A brief introduction to Customization

A Brief Introduction
to Customization
By Mark Klein, Vincent Forte, and Steve Hubert

This introduction of our five-part series is focused on
optoelectronic customization, and how both emitter and
detector components and assemblies can be specifically
designed for your application, including in-depth analysis of
materials, packaging, and testing.
Customization: To make or alter based on individual specifications or preferences.
The goal of this series is to provide design engineers with details concerning customized components and
assemblies, such as physical constraints and how to optimize electrical, optical, and thermal characteristics.
Part 1: Custom emission materials
Does your application require tight binning? In this article, we will explore how specific wavelengths can
optimize your product’s performance. We will explain how
your choice of chip and other factors, including how you drive
the component, will affect degradation and the lifetime of your
product. What chip mounting options are best-suited for your
application? This article will cover wire bonding techniques,
die attach (eutectic or conductive paste), illumination patterns,
and output.
Part 2: Custom detection materials
In this article, we will cover the materials that are used in
silicon detectors, including PIN photodiodes, photodiode
arrays, Avalanche photodiodes, and other detector products. We’ll review your options to customize either
N-type, P-type, or epi-materials to optimize chip design, with consideration for characteristics like minimum
reflection, low-dark current, minimum series resistance, low capacitance, fast response, and low crosstalk.
Part 3: Packaging
Once you have chosen the chip, the packaging criteria comes into play next. You need to define what
important criteria are needed, for example, space constraints. Packaging options include SMD (surface
mount devices), COB (chip on board), through-hole devices, and TO-cans, including multi-chips, which may
contain both emitter and detector chips.
Does your application require multiple chips, either for emission or detection or both? What is the best

material for your assembly: FR-4 to ceramic, flex, or metal
core? Depending on your application, you must determine
how many chips are required based on outputs and drive
conditions.
Depending on your choice of chip and package, conditions
such as heat dissipation and electromagnetic interference
should be considered. In this article, we also will explore
lensing options to modify radiation patterns, such as wide or
narrow viewing angles, or custom illumination patterns.
Part 4: Design, Testing, and Binning
Part 5 in the series will cover design, testing, binning, and
quality control. Depending on your application, you may
have a need to test for optical and electrical parameters
on both emission and detector components, materials,
and assemblies. You may even require unique testing
capabilities on detectors including spectral response,
quantum efficiency, shunt resistance, dark current, and
capacitance. On the emission side, testing is sometimes
required on both UV and SWIR devices.
Part 5: Getting Started
Part 5 in the series will be a wrap-up summary of Parts of
Parts 1 through 4 and will highlight the next steps to take if
you are interested in pursuing a custom device, beginning
with initial discussions with an application engineer. We
will discuss the various steps to bring your idea from
concept to prototype to finished component or assembly.

Customization of
Optoelectronic Emitter
Materials
Part 1 of a 5 part series

Custom packaging and electrical sorting of product offer further differentiation. Marktech provides the
designer with insights concerning custom variations–variations that optimize electrical, optical, and thermal
characteristics–without the need for large volume commitments.
To solve your needs, Marktech engineers will discuss with you:
• Application needs specific to your project
• Optimization recommendations for component and assembly packaging, technology, and thermal and
electrical parameters
• Manufacturing of dedicated end-products in support of your specifications and needs
In this part of Marktech’s customization capabilities series, we focus on optoelectronic emitter materials,
materials typically intended for mating with compatible (and possibly customized) detectors.
Emitter wavelengths
Available products have wavelengths varying from 280nm (UV) through visible (440 to 700nm) to Near IR
(710nm - 1100nm) and short wavelength infrared (up to 3000nm). Our online Product Selector Guide helps in
the selection of emitter wavelengths, while also indicating compatible detectors. Tight binning by Marktech
can provide uniform color characteristics to optimize the application and mating detectors’ sensitivities,
providing process-controlled, uniform product solutions.
LED drive current and temperature
Optimal drive current and temperature minimize degradation/ lifetime effects.
Forward current vs. ambient temperature:
Figures 1 and 2 show an example in which the current is derated to take temperature into account. CREE
technical data for LED lamps usually shows the permissible current values against temperature. Refer to this
information when planning a new design.
Utilizing our 30 years of experience in optoelectronics,
Marktech’s customization process focuses on customer needs
and applications. Instead of using standardized–but perhaps
non-optimized–parts, Marktech allows advantageous custom
product variations to enhance your product design.

The following example describes how to derate for temperature when designing:
Figure 1 - Specified by design (25 mA) exceeds permissible value at 70C high temperatures
Figure 2 - Specified by design (25 mA) is within permissible value at 70C high temperatures
LED lamp example:
• An LED lamp is to be used at an ambient temperature of 25°C.
• To obtain the required luminosity, set the LED lamp current to 20 mA.
• The guaranteed operating temperature range for the equipment is -10° to +70°C.
• If the current is derated for temperature, as shown in Figure 1, at 70°C the LED lamp current must be set
to 20 mA or less. Hence a design that yields an LED lamp current of 25 mA is not permitted. However,
some other types of LEDs that emit the same color have their current derated to take temperature into
account, as shown in Figure 2. Since those LEDs can maintain a current of about 30 mA at a temperature
of 70°C, they satisfy the above design conditions.
50
IF(mA)
Ta( C)
40
40 60 80 100 120
30
20
20
10
0
0
FIGURE 1 BLUE & GREEN MAXIMUM
FORWARD DC CURRENT VS
AMBIENT TEMPERATURE (Tjmax = 105 C)

Derating for longevity:
Characteristically, the luminous intensity of LEDs gradually decreases over the life of the LED. The rate at
which the luminous intensity falls varies according to the material used and the forward current at which
the LED is driven. The larger the current, the greater the diminution of luminosity. Thus, when setting the
forward current of the LED lamp, do not determine the setting solely from the temperature characteristics,
as in the above example, but consider also longevity characteristics. An effective way of improving the
longevity characteristics is to set the forward current of the LED lamp relatively low.
Chip mounting: Die attach and wire bonding
What chip mounting options are best-suited for your application? Simpler wire-bond techniques and
conductive paste die attach are acceptable for low-power devices, but as power increases, increased
thermal conductivity is needed to assist in lowering chip temperatures.
Die attach:
• Conductive epoxy die attach: good for low/ medium power applications
• Soft solder die attach: good/ very good for low or high power applications
• Eutectic solder die attach: good/ very good for high power applications
• Advanced Eutectic (thermal compression bond Gold Silicon): very good for high power applications.
Difficult to apply
Wire bonding: (Source: Hybond, a wirebonder manufacturer):
There are three types of wire bonding:
• Thermocompression bonding
• Thermosonic bonding
• Ultrasonic bonding
Thermocompression bonding: A process that involves the use of force, time, and heat to join the two
materials by inter-diffusion. The wire (heated in some cases) is pressed against the hot surface (at 150°
C or more) at high force for a limited period of time to achieve the bond. No friction is used. This process
uses gold wire and a gold bond surface, and it was originally associated with ball bonding. To this day,
there are still some people who will use the phrase “thermocompression bonding” as a synonym for ball
bonding, even if it now uses ultrasonic friction.
Thermosonic bonding: A process that involves the use of force, time, ultrasonics, and heat to join
two materials. The wire (heated in some cases) is pressed against the hot surface (at 150° C or less)
at low force and vibrated for a limited period of time to achieve the bond. This process uses gold wire

and a gold bond surface, and it was also originally associated with ball bonding because the first time
ultrasonics were used as a bonding parameter, it was done with ball bonding.
Gold ball bonding: So-named because it is the bonding of a gold wire, which, in its initial stage, has a
ball or sphere formed on the end. A “flame-off” is used to make the ball. Originally the flame-off was
done with an open hydrogen flame which would rotate towards the end of the wire and melt it, creating
a sphere at the end of the wire. Currently the ball is made with an EFO (electronic flame-off), which
creates a spark to melt the end of the wire. This bonding process uses force, time, ultrasonics, and heat
to make bonds. As of recent years, copper wire has begun to be used for this process, but equipment
must have modifications to prevent oxidation of the wire and especially the ball during its formation at
flame-off.
Wedge bonding: This process was originally exclusive to aluminum wire, and no heat was used
to create bonds. With time, heat was added to the bonding surface and gold wire was used for
thermosonic wedge bonding of the gold wire. This is now a common form of bonding gold wire or
ribbon. It should be noted, however, that some people still use the phrase “wedge bonding” as a term
for ultrasonic (explained below) and not thermosonic wire bonding. Regardless of the traditional
meaning of the phrase “wedge bonding,” the thermosonic wedge bonding process uses force, time,
ultrasonics, and heat to make bonds.
Ultrasonic bonding
Ultrasonic bonding: is a process that involves the use of force, time, and ultrasonics to join two materials.
The wire is pressed against the surface (both at ambient temperature) at low force and vibrated for a limited
period of time to achieve the bond. This process can be done with gold, aluminum, copper, palladium, silver,
or platinum wire or ribbons and to bond surfaces of the same materials. Originally, this form of wire bonding
was done only with aluminum wire, so to this day, there are still some people who will use the phrase
“ultrasonic bonding” as a synonym only for aluminum wire wedge bonding, even if it now is used for gold
wire wedge bonding and other materials as well.
Wedge bonding: This process uses force, time, and ultrasonics with the bonding surface at room/
ambient temperature to make bonds. Although originally exclusive to aluminum bonding applications,
today there are many other materials and alloys that can be bonded by the ultrasonic method, including
some thought at one time to only be effective if heat was applied.
Peg bonding: This process uses force, time, and ultrasonics with the bonding surface at room/ambient
temperature to make bonds. Although peg bonding is exactly the same as wedge bonding, and can be
done thermosonically as well as ultrasonically, the main difference with the techniques described earlier

is that in a peg bonder, wire is not fed from a spool of wire by the wire bonder. Instead, the wire or ribbon
(or any conductor in general) is either pre-aligned over the bond pad or it is manually introduced under
the bonding tool (peg) to be bonded. A more common name to this process is TAB (tape automated
bonding) or single point TAB. Hybond has given the name “peg” to this type of bonding because naming
it TAB would lead to the assumption that a tape-feeding mechanism would be included as part of the
equipment, and in reality, it is not. The name peg is also given by Hybond because the tool used for
bonding usually looks like a peg, just as the tool used in wedge bonding looks like a wedge.
Today, ultrasonic bonding is a different process from what it was originally thought to be. The concept of
interfacial rubbing is not valid. Ultrasonic energy, when applied to metal to be bonded, renders it temporarily
soft and plastic. This causes the metal to flow under pressure. The acoustic energy frees molecules and
dislocates them from their pinned positions, which allows the metal to flow under the low-compressive
forces of the bond. Thus heat at the bond site becomes a byproduct of the bonding process, and the external
heat becomes unnecessary to form the bond. This is also called a “cold weld.”
The friction of the wire breaks up and sweeps aside some contaminants in the weld area exposing clean
metallic surfaces that promote the metallurgical bonds. It is important, however, to begin with a clean
surface to avoid difficulties or failures in bonding. In some cases, the ultrasonic scrubbing may not be able to
remove contaminants, as in the case of lubricants.
It also was found that the bonding tool moves cyclically across the top of the wire. A regular flat tool may not
grip the wire well enough, and this causes the wire to slip back and forth across the bond surface of the tool.
For this reason, there are tools that are made with more porous materials, such as ceramic-metal alloys, or
that have special features like cross-grooves or grids that assist in the gripping of the wire during ultrasonic
and thermosonic bonding.
Lensing: Illumination patterns and output
Spatial radiation characteristics: Lenses determine the angle-dependent output power obtainable. Lens
characteristics determine intensity peaks and coverage areas. Marktech products provide great choice in
beam angle, and these need to be matched to the application and sensor needs. Marktech uses goniometer
equipment to analyze these radiation patterns.

Luminous intensity and directional characteristics: Relationship between luminous intensity units and
directional characteristics. Luminous intensity is measured in candela (cd), and the radiance is measured
in watts/steradian (W/sr). One steradian is the solid angle at the center of a one-meter-radius sphere
subtended by a square meter of surface area. The steradian is a metric unit. The radiance of light is the
amount of luminous flux propagated in a given solid angle, or the amount of incident. Hence, as the figures
below show, the narrower the directionality of an LED lamp, the higher the luminous intensity of that lamp.
Hence, for an LED lamp of given directionality, the higher the emission efficiency of the chip, the higher the
luminous intensity.
Visit Digikey for a listing of select Marktech emitter chips ranging from deep UV to the visible range to near-
infrared and short wave infrared (SWIR).
View a full listing of Marktech emitter chips ranging from deep UV to the visible range to near-infrared and
short wave infrared (SWIR).
Application Viewing Angle
High-Brightness LED information panel
Signal applications
Low-Brightness LED information panel
Narrow-Direction indicator
Wide-Direction indicator
Automotive stop lamp
Automotive dashboard narrow directionality
Automotive dashboard wide directionality
15° to 30°
8° to 30°
30° to 120°
30° to 60°
60° to 120°
20° to 50°
20° to 60°
60° to 120°

Examples of customized products
Custom light rings
Custom light rings applications:
• Analytical instruments for the biochemical industry, medical and scientific analysis, endoscopy
• Critical illumination
• Security cameras
Marktech solution:
Constructed with FR-4, metal core, or ceramic construction, Marktech’s ring/
chip offerings range from 280nm in the UV range though visible to near IR;
white light ring options can be made with color temperatures ranging from
warm (2600K) to cool (10000K). Emitter or detector chips–or a combination
of both–can be included in custom light ring packages. In most cases,
Marktech can test to plus or minus 1 nanometer. Their size offerings range
from 4mm up to any required size.
Smaller size light rings are typically manufactured with COB [chip on board] technology, however, standard
surface mount components such as 0805, 1206, and PLCC-type packages are also available depending on
the optical performance required.
Pulse oximeter: Oxygen and pulse rate monitoring
Typical medical physicals now include quick and reliable readings of patient oxygen levels, findings that can
be duplicated with home monitoring due to the low cost of access to the equipment. The oxygen levels of
your blood are easily determined by a simple pulse oximeter where two different LED emitter wavelengths
are used. Oxygenated blood tends to absorb light at 660nm; deoxygenated blood absorbs light better at
905nm. By making measurements and interpreting the results using Beer-Lambert’s law, the saturated
peripheral oxygen level from your fingertip is quickly determined.
What’s needed:
• Customized packaging of emitter parts to conveniently fit in a small
package
• Optimization of the part wavelengths to increase accuracy

Marktech solution:
Design, purchase, and modify LED-sorting equipment to bin LED products into tighter than +/- 1nm selected
chips.
UV curing and drying of inks, adhesives, and coatings
Ultraviolet LED emitter light curing is now used for applications
ranging from dentistry to guitar finishes, including automotive,
telecommunications, electronics, graphic arts, glass, and plastic
decorating. Inks, coatings, and adhesives cured with UV LED
light have dramatically improved physical properties. Traditional
curing used highly inefficient and environmentally objectionable
mercury lamps that could potentially damage the subject matter
if misapplied. UV LEDs, on the other hand, are highly efficient and
offer a longer-life alternative to standard bulbs. Heat output is easily
controlled with LEDs while also lowering the time needed to cure,
reducing the potential for damage to the cured object.
Advantages are:
• Fast production speeds/increased capacity
• Dramatically reduced set-up/clean-up labor
• Environmental considerations for emissions and energy use
• Less floor space needed
• Increased manufacturing efficiency
Marktech solution:
Marktech can optimize the emission wavelength for camphorquinone (CPQ) and other alternate materials
that can be used as the curing photoinitiator. Packaging can be optimized for access to, for instance, small
dental probes optimized for patient use.
For more information, see: http://blog.marktechopto.com/4-ways-uv-leds-are-changing-our-world/
Customized displays
Times Square in New York City is an exciting, visually awesome area. Marktech has
contributed to this area and to other large display applications with customized display
capability including:
• Display visibility 12-16 blocks away and 60 feet below

• High quality – Zero defects /zero failures since 1996!
• Design solution of two-chip assembly with elliptical lens
• Cooperative manufacturing agreement with Toshiba
Bar code scanning
Bar code readers use emitters with:
• Consistent power output
• Repeatable wavelengths
Marktech solution:
Design, purchase, and modify equipment to sort LEDs for power output, with selected/consistent binning.
SWIR (short wavelength infrared) emitter applications
Short wavelength infrared (SWIR) LEDs are the
latest addition to Marktech’s broad line of emitters.
Marktech Optoelectronics is one of only a handful of
manufacturers that supply emitters in the extended
wavelength or SWIR range. Available in a variety of
through-hole and surface mount packages, SWIR
emitters satisfy a growing need for high-speed light
emission in ranges not easily seen by standard detectors
and are also being used for material and chemical
analysis.
Typical industries served:
Medical, security, military, communications, industrial, and agriculture
Common applications:
The rapidly growing market for SWIR includes applications like produce inspection, security, surveillance,
anti-counterfeiting, biomedical bioflorescence and blood chemistry analysis, night vision, safety equipment,
currency validation, fiber optics, and inspection system devices. SWIR detectors can help realize non-
invasive imaging methods, for example, optical coherence tomography (OCT) systems, utilizing SWIR to
exploit the low scattering properties of >1μm light to see the previously unreachable, thick parts of the
cornea.
Marktech solution:
Marktech’s standard product offerings includes both through-hole and surface mount packages with

wavelengths from 1050nm to 1720nm and operating currents ranging from 20mA to 350mA for high-power
applications. Higher wavelength ranges up to 3000nm are available in specific package types.
The Marktech extended wavelength standard SWIR package offerings include TO-46 flat, TO-46 lens,
TOPLED PLCC4, SMD 1206, SMD 1206 Lens, and SMD high-power black. Custom package options are also
available.
To learn more about Marktech, optoelectronic emitters, or our start-to-finish
customization capabilities, visit our website at
www.marktechopto.com.

Customization of
Optoelectronic Detectors

Custom packaging and electrical sorting of products offer further differentiation. Marktech provides the
designer with insights concerning custom variations–variations that optimize electrical, optical, and
thermal characteristics–without the need for large volume commitments. With manufacturing facilities in
California, Germany, and Japan, Marktech is a vertically-integrated company, allowing us to produce detector
components quickly, thus decreasing your time to market. We can even produce your entire package in the
United States, if need be.
To solve your needs, Marktech engineers will discuss with you:
In this installment of our customization capabilities, we focus on optoelectronic detector materials, to allow
options to customize detector components for optimal mating with compatible emitters.
Overview
Photodetectors are sensors, detecting light and converting the photons into measurable currents, and
are therefore useful for applications ranging from water faucets to nuclear transient events. With varied
technologies and packaging, specific measurements can be made that are ideal for your applications.
Marktech devices are solely solid-state devices (there are no photomultiplier tubes in our product line,
although our products may supply similar functionality). Response rates can be as fast as 300 picoseconds.
Light levels that can be measured range from tens of photons to massive levels. Wavelengths can range
from 150nm to greater than 3000nm.
Each photodetector uses p-n or n-p junctions as part of either a photodiode or phototransistor construction,
effectively working as an inverse function from the typical operation of a light emitting diode. Depending on
the technology used, the detectors provide current response to specific ranges of light wavelength.

Detector Materials and Characteristics
The materials used may be silicon, GaP, or InGaAs. The P and N epitaxial layers of the wafer materials can
be optimized for specific customer specifications and desired characteristics, including minimum reflection,
Optimized Responsivity, low dark current, minimum series resistance, low capacitance, fast response, low
cross talk, and more. The detectors can be packaged in a variety of packages from metal can and standard
3mm and 5mm plastic packages, to surface-mount...or virtually any custom package assembly. Detector
applications range from simple door opening to the latest cancer PET scan system.
Detector Wavelengths
Available products have wavelengths varying from 150nm (UV) through the visible range (440 to 700nm),
through SWIR (short wavelength infrared) (up to 2600nm), and beyond to MWIR (medium wavelength IR)
(>3000nm). This link to our online Product Selector Guide helps in the selection of the emitter wavelengths,
while also indicating compatible detectors. Tight binning by Marktech can provide uniform wavelength
characteristics to optimize the application and mating detectors’ sensitivities, providing process-controlled,
uniform product solutions.
Marktech Photodetector Variations:
• Silicon photodetectors (400nm to 1100nm): photovoltaic, photoconductive photodiodes, and
phototransistors
• Silicon avalanche photodiodes (400nm to 1100nm, with 800nm, 905nm optimization)
• UV detectors (150nm to 450nm)
• InGaAs PIN photodetectors (800nm to 2600nm) and SWIR (short wavelength IR) detectors (1050nm to
1720nm)
Products are also available in epitaxial wafer form, and can be packaged as photoreflectors, arrays, and
hybrid parts. For part listing and additional information, visit our detectors catalog.
Silicon Photodetectors (400nm to 1100nm):
Marktech’s silicon phototransistors can be utilized in applications requiring very high sensitivity, uniform
response, and increased reliability such as card readers and optical sensors.
The photovoltaic silicon photodetectors have a spectral sensitivity from near-ultraviolet, through the visible
range, to short wavelength Near IR (400nm to 1100nm). These are used in applications such as medical,
analytical, communications, spectroscopy equipment, and sensing requiring broadband sensitivity with
enhancements in the blue/green region. These devices can exhibit moderate-speed response, high
sensitivity, and low noise. Devices are available as either phototransistors or photodiodes.
The photoconductive silicon photodetectors are suitable for high-speed and high-sensitivity applications.

The spectral range extends from 400nm to 1100nm, making these photodiodes ideal for visible and near-IR
applications, including such AC applications as detection of pulsed LASER sources and LEDs.
Marktech’s broad line of silicon photodetectors are provided in a variety of package types including through-
hole plastic, ceramic, metal-can, surface mount, and full custom. These devices are available with standard
silicon die having a spectral sensitivity of approximately 400nm to 1100nm, or with special UV-enhanced
silicon chips with sensitivity in the lower UV-A range. Custom active areas and multi-element chips can
also be manufactured to suit your application. Many of our wafers/chips are manufactured in the USA and
optimized to insure uniform and consistent performance with high reliability. These devices are well-suited
for visible and near-IR applications requiring high speed and high sensitivity as well as low noise such as
optical switches and optical communications.
Marktech silicon detectors can be obtained with integrated filters for reduced visible light interference or
optimized for your required spectral output. In addition to our various package styles available off-the-shelf,
Marktech can integrate multiple detectors and/or emitter detector combinations in a single package type.
Silicon photodetector variations:
• Silicon phototransistors
• Avalanche Photodiodes
• Silicon photodiodes in SMT, through-hole DIL, and metal can packaging
• Photodiode arrays
• Dual/quadrant photodiodes
• X-ray detectors
• Multichip photodiodes for expanded wavelength or sensitivity
• Silicon photovoltaic PIN photodiodes
• Silicon photoconductive PIN photodiodes
• Silicon PIN photodiodes with enhanced blue sensitivity
• Silicon photodiode arrays
• Differential photodiodes
Customized optimizations:
• UV blue-green NIR (near-IR)
• 1064nm, 2200nm, and 2600nm
• Minimum reflection
• Low dark current
• Minimum series resistance
• Low capacitance
• Low carrier lift time

• Fast response
• Low cross-talk
Customized packaging:
• Tested wafers
• Chips
• Hermetic packaged devices
• Hybrids (detector/amplifier in one package)
• Detector/filter combinations (bandpass or color glass)
• Hybrid/modules (ceramic or COB [chip on board])
Typical industries served
Medical, optical communications, industrial, scientific, and analytical
Common applications
Remote controls, optical encoders, position sensors, fiber optics, barcode readers, and chemical analysis.
Silicon Avalanche Photodiodes
(400nm to 1100nm, optimized for 800nm and 905nm)
Avalanche photodiodes are ideal for high-speed and low-light level detection in the near-infrared range.
These detectors have become the semiconductor equivalent of photomultipliers in many applications
including data communication, LIDAR, instrumentation, and photon counting. In addition, cost-effective
customization of these APDs is offered to meet exacting design specifications. Operation voltage selection
and voltage breakdown (Vbr) binning, wavelength-specific band-pass filtering, and hybridization options
are among many of the application-specific solutions available at Marktech.
Marktech APDs have an internal gain mechanism, fast time response, low dark current, and high sensitivity
in the near-infrared region. These APDs are recommended for applications that require high bandwidth or
where internal gain is needed to overcome high pre-amp noise. In addition, Marktech APDs provide higher
sensitivity than a standard photodiode and are ideal for extreme low-light level detection and short pulse
detection. APDs are essentially photodetectors that provide an amplification gain stage through avalanche
multiplication. They are similar to photomultipliers but are solid state semiconductor devices.
Silicon Avalanche photodiodes (Si APDs) are the preferred optical detectors for applications where the
wavelength lies between 400nm and 1100nm (with 800nm and 905nm optimized sensitivities), and exhibit
high speed and low noise for visible to near-IR applications. Standard versions are available in three active

area diameter sizes: 200, 500, and 800um and are offered in hermetic TO cans and can also be supplied in
cost-effective LCC packages.
UV Detectors (150nm to 570nm)
UV LEDs are becoming more prevalent in the industry, replacing old technology such as mercury lamps. As
a result, the need for UV detection is also increasing. Marktech UV detectors are offered in a variety of TO
metal can-type packages from TO-18 to TO-39 with a special UV glass lens to ensure optimum lifetime and
the least amount of material degradation. Marktech offers both standard and custom packaging including
components, assemblies, and bare chip options to match your application requirements.
Our UV detectors use materials including GaP Schottky, GaN, and SiC. A die can be packaged individually in
a variety of hermetically sealed packages or multiple die can be integrated in a custom package to suit your
specific application. Marktech UV detectors offer superior stability over time and high device sensitivity with
low dark current.
UV-A: Marktech also offers, on a custom basis, silicon-based UV detectors, which are designed for
operation in the UV-A range. These devices are available in plastic and surface mount packages in
addition to the standard TO metal can-type.
Typical industries served: Medical, industrial, scientific and analytical, environmental/ecological, and
commercial
Common applications: Biomedical/chemical analysis, UV emitter output monitoring, outdoor UV
sensors, gas/flame detection, spectrometers and wearable devices, emitter calibration, UV dosimetry
and imaging including solar UV measurements and astronomical studies, flame sensors (fire alarm
systems, missile plume detection, combustion engine control), spatial optical communications (intra-
and inter-satellite secured communications), and biological and chemical sensors (ozone detection,
determination of pollution levels in air, and biological agents detection).
InGaAs PIN Photodetectors (800nm to2600nm)
Thishigh-sensitivity and high-reliability product series is ideally suited for applications in the SWIR (short
wavelength infrared) wavelength range. This high-sensitivity and high-reliability product is ideally suited for
optical communication devices.
Photodiode chip active area sizes from 0.1mm to 3.0mm are available to provide the optimum balance
between low dark current, high speed, and light sensitivity. This allows for increased flexibility and options

in a variety of applications ranging from fiber optics and high-speed optical communications to medical and
chemical analysis.
Integrated TE (thermal electric) cooling is currently not utilized on our standard PIN photodiodes, thereby
reducing costs and improving overall efficiency.
In addition to PIN photodiodes, Marktech offers foundry services for epitaxial growth of SWIR wafers in the
1.0um to 2.6um range, using InP material as the base substrate. Marktech is currently producing these high-
reliability wafers in 2”, 3”, and 4” diameters. Among the applications for these wafers are photodetectors,
linear arrays, and image sensors. Photodetectors processed using our epitaxial wafers provide significant
advantages, including lower dark current, better shunt resistance, and overall improved performance at
lower operating temperatures.
Marktech manufactures InP PIN photodiodes using InGaAs/InP technology, which have a spectral sensitivity
in the 800nm to 2600nm range for applications requiring low dark current, high speed, and sensitivity such
as fiber optics and optical communications. Marktech’s detector die can be placed in a variety of packages
from metal can TO-5, TO-18, and TO-46 to surface mount and standard 3mm and 5mm plastic packages.
We can also incorporate the detector die in custom-designed assemblies.
SWIR (Short Wavelength IR) Emitters (1050nm to 1720nm)
Marktech Optoelectronics is one of only a handful of manufacturers that supply emitters in the extended
wavelength or SWIR range. Marktech’s standard product offering includes both through-hole and surface
mount packages with wavelengths from 1050nm to 1720nm and operating currents ranging from 20mA
to 350mA for high-power applications. Higher wavelength ranges up to 3000nm are available in specific
package types.
The SWIR wavelength range requires specialized optical detectors since standard silicon detectors have a
maximum sensitivity limit of up to only approximately 1100nm. Marktech produces a line of InGaAs detectors
that are optimized for sensing light in this SWIR wavelength range. These detectors can be obtained as
an individual, discrete component, or they can be combined with a silicon sensor to cover the complete
spectrum of light from the visible to the SWIR range. Marktech also offers the option to custom-produce
multi-element devices with emitter and detector chips in the same package.
The Marktech extended wavelength standard SWIR package offerings include:
• TO-46 flat
• TO-46 lens
• TOPLED PLCC4

• SMD 1206
• SMD 1206 lens
• SMD high-power black
Marktech’s optoelectronic manufacturing and assembly capabilities include:
• SMD, through-hole, and chip on board assembly
• High-density pick and place
• Prototyping
• Small- to high-volume production runs
• PCB design and fabrication
• Single or multi-layer
• Flexible or rigid
• Aluminum, FR4, ceramic, and polyimide
• Schematic capture
• PCB design
• Simulation
• CAD/CAM
• Consigned or purchased materials
• In-circuit testing
• Reliability testing
• Potting
• Conformal coating
• IPC standard assembly
• Use of your part numbering system
• Shipped to your packaging requirements
Additional outsourced capabilities include:
• Plastic injection molding
• Metal work fabrication
• Optical analysis
• Thermal analysis

Photodetector Applications:
• Astronomy: Space-based telescopes with far-IR wavelengths
• Automotive: Driver vision in low light, collision detectors, twilight detection
• Banking: Counterfeit detection in currency
• Communication: Fiber optic communication (typically operates in the infrared wavelength) with very
high rise time (response rate) to allow high data rates of up to 100 gigabits/second, silicon photodiodes
used for short wavelength links (650 for POF and 850 for glass MM fiber), long wavelength systems
used in InGaAs (indium gallium arsenide) detectors as they have lower noise than germanium (which
allows for more sensitive receivers), very high speed systems using avalanche photodiodes (APDs) that
are biased at high voltage to create gain in the photodiode
• Chemical/biological: High-speed detection
• Consumer: Household electronics (radios, DVD players, TVs, computer sensors), cameras
• Environmental: Detection via spectroscopy for pollutants and particulates, global temperature
monitoring via space-based sensors, thermal imaging for home and business heat loss/efficiency,
recycling (material identification from fluorescence of plastics/glass)
• Industrial: Robotic imaging/sensing, video camera imaging, process control through temperature
monitoring, arc light detection (ultraviolet wavelength detectors are offered in applications where
mercury lamps and UV LEDs are used), bar coding
• Medical: Pulse oximeters, CAT, and PET scans
• Military: Night vision applications, intake/exhaust temperatures for aerospace
• Municipal: Monitoring of water purification for municipal water supply, pools
• Safety/Security: Smoke/flame detection, TSA security
SWIR for Night Vision Applications
Arrays of SWIR detectors have been utilized in SWIR night vision systems, which rely on the intense night
glow that can illuminate the scenery even when there is complete darkness in the visible spectrum.

SWIR Detector for Homeland Security Applications
Applications in Medical & Biophotonics
SWIR detectors can help realize the non-invasive imaging methods, for example, optical coherence
tomography (OCT) systems, utilizing SWIR to exploit the low scattering properties of >1μm light to see the
previously unreachable, thick parts of the eye’s cornea.

SWIR Industrial Applications
Inspection for High-Temperature Manufacturing Processes: Web inspection of continuous processes
such as high-temperature manufacturing processes and quality controls.
Recycled Plastics Resorting Application: SWIR can be used in the recycled plastics industry due to C-H,
O-H, and N-H found in plastics, and uses wavelength around 1.0-2.2μm.

SWIR Applications in Agriculture
SWIR detectors, such as 1240nm, 1640nm, and 2130nm, combined with visible detectors, can be applied in
some remote sensors for soil moisture and agricultural drought monitoring.
SWIR imaging can provide more information about rock and soil features better than visible images due to
the reflection characteristics of rock and soil in the 1.8um to 2.5um range.

LIDAR Applications
LIDAR (light detection and ranging) is a surveying method that measures distance to a target by illuminating
that target with a laser light. LIDAR uses laser light pulses, while radar uses radio waves. Avalanche
photodiodes enable the LIDAR application as a remote sensing technology that optically measures
properties of scattered light to find range and/or other information about a distant target.
To learn more about Marktech, optoelectronic emitters, or our start-to-finish
customization capabilities, visit our website at
www.marktechopto.com.

Customization of
Optoelectronic Packaging

Custom packaging and electrical sorting of product offer further differentiation. Marktech provides the
designer with insights concerning custom variations–variations that optimize mechanical, electrical,
optical, and thermal characteristics–without the need for large volume commitments. With manufacturing
facilities in California and Japan, Marktech is a vertically-integrated company, allowing us to produce emitter
and detector components quickly, thus decreasing your time to market. We can even produce your entire
package in the United States, if need be.
To solve your needs, Marktech engineers will discuss
In this third installment in our five-part series on Marktech’s customization capabilities, we focus on
Optoelectronic Packaging, to provide the physical and optical forms to optimally solve application needs.
Overview
Once the emitter and/or detector electrical characteristics and chip sizes are determined (as discussed in
earlier parts of this series), packaging design for these devices is needed in order to meet the goals of optical
efficiency (along with viewing/radiation angle), space constraints, heat dissipation (and resultant reliability),
electromagnetic interference, and product cost. The finished design is then prototyped and then electrically
and environmentally screened as required.
Packaging provides the necessary interface between the semiconductors and the physical world to provide
optimal electro-optical performance as well as the physical strength and reliability of the device. Optical
designs maximize light output and power transfer for the desired viewing angle. Packaging can contribute
50 to 80% of the manufacturing expense of the optoelectronic assemblies.

Optically clear silicones and epoxies are typically used for potting, molding, or encapsulation.
• Silicones are often used for high powered devices due to stable thermo-optical properties. Silicones
are very stable in upper UV and blue light, even under high intensity, humidity, and temperature.
They are also useful when incorporated into surface mount technology (SMT), where optical and
mechanical stability are needed after exposure to solder reflow temperatures. Silicone attributes are:
high transparency in the UV-visible region, controlled refractive index (RI), stable thermo-mechanical
properties, and tunable hardness from soft gels to hard resins. A silicone can have a glass transition Tg
below 0°C, but due to its flexibility and elasticity, it can be used at high and low temperature extremes.
• Epoxies are typically used for general purpose, low to medium power devices, and have a long history
of use dating to the 1960-1970’s, with improvements in formulations along the way that have provided
low cost and high reliability. The glass transition temperatures of epoxies are lower than for non-optical
devices (65C is typical). High temperatures can cause mechanical stresses, as well as degrade light
transmission over time.
Die attachment is typically provided by silver filled epoxy or, for more heat transfer by Direct
Attachment (DA), Flip Chip attachment, or solder eutectic.
• Epoxy die attach material is silver filled to provide thermal and electrical conductivity. Additional
desirable attributes are: low outgassing, low bleed, good adhesion characteristics, and high glass
transition point (typical value: 140C).
• Direct Attachment (DA) employs an efficient flux eutectic bonding process for attaching chips without
the use of epoxy. The technique uses a process which eliminates the need for solder paste, preforms or
conductive adhesives (see below for more detail).
• Flip Chip die attach uses a solder bump bonding method (see below for more detail).
• Solder is used for some high power devices, but also as mentioned for Flip Chip chip on board (COB) use,
where the controlled –collapse chip connection soldering allow self-alignment of devices as well other
electro-mechanical advantages.
Substrate materials can be metal lead frames, standard TO style metal headers, ceramic headers, and
printed circuit boards of FR4, ceramic construction, or metal core. Ceramic packaging is preferred when
higher thermal stability is required, with low-temperature co-fired ceramic substrates in common use.
Selection of materials to provide needed CTE (coefficient of thermal expansion) enhances the thermal path
from the chip to the heat sink, thereby lowering the junction temperature of the chip and improving quality/
reliability.
Chemical compatibility with packaging materials should be reviewed with Marktech, as acids and solvents
may not be compatible with reliable product use.

Temperature concerns:
The development of high-power GaN visible chips for commercial use since the 1990’s (with >150 lumens
per watt for LED’s replacing tungsten’s characteristics of 12 lumens/watt) have required an evolution from
standard lead-frame/molded epoxy 5mm and similar lamps to allow for the heat generation and general
power requirements of the newer high lumen output chips produced by Cree (and sold through Marktech for
custom use). Evaluation Star and Linear boards from Marktech help in characterization of these products.
Care is needed to not exceed maximum junction temperature specifications, and it is beneficial to derate
the temperature of the parts for reliability. Thermal management is a key aspect of packaging for high-
power LED’s. Overheating can decompose the silicone of the inner lens, which then can become corrosive.
Overdriving can carbonize the inner lens above the LED. Thermal expansion can cause broken wire bonds or
die attach separation.
LED manufacturing volumes are typically lower than for non-optoelectronic microelectronics, where shorter
cure times are used for packaging, and where reflowing solder may extend temperatures to 200C. Many
optoelectronic assemblies are damaged at temperatures between 100C to 125C. Solder temperature and
duration must be in accordance with recommendations.
Here are thermal conductivities for varied assemblies (in Watts per meter x degree Kelvin):
• FR4 printed circuit board: 0.23 W/mK
• Alumina or LTCC (low temperature co-fired ceramic) board: 25 W/mK
• Metal-core copper heatsink board: 400 W/mK
• Flip chip LED’s with silicon backing: 150 W/mK
Alternatively, the following graph shows the progress in thermal efficiency for the newer packaging
variations.
Thermal Resistance Comparison (Junction to Pad)

Customized assemblies
Customized assemblies can provide prototypes for what-if product builds, evaluation test products, and
products incorporating specific emitter and detector chips needed for demanding customer applications.
Note: Marktech works with the entire Cree dice line, and can provide customization of products incorporating
any of this product. In addition, Marktech provides customization of Marktech’s own specialized visible, IR,
and UV dice.
Customized assemblies use selected emitters, detectors, and packaging, as detailed below.
Examples of Customized Products
Customized emitters
These can consist of Cree and Marktech UV, visible, and NIR /SWIR (near infrared/ short wavelength
infrared) chips.
These include:
• High-brightness and high-power LEDs
• Multichip emitters and chip-on-board packaging
• Infrared, ultraviolet, and visible LED emitters
• Single or multi-chip LED packages or modules for multiple wavelength applications
• Single or multiple LED die configurations

Available LED emitters have wavelengths varying from 280nm (UV) through visible (440 to 700nm) to
short wavelength infrared (SWIR; up to 3000nm). Our online Product Selector Guide helps in the selection
of emitter wavelengths, while also indicating compatible detectors. Tight binning by Marktech can provide
uniform color characteristics to optimize the application and the mating detectors’ sensitivities, providing
process-controlled, uniform product solutions.
Cree emitter dice custom assemblies
Cree dice can be custom packaged by Marktech for specific application needs. Marktech is one of only
a small number of suppliers with this access to Cree dice. Marktech provides expertise in both Direct
Attachment (DA) and Chip On Board assembly techniques. Cree is a major supplier of DA chips.
Customized detectors
Customized detectors are photo transistors and photodiodes with the ability to detect light in the UV, visible,
and infrared spectrums. These include:
• Standard photovoltaic silicon photodiodes
• Silicon photo transistor and Avalanche photodiodes
• Specialty photo detectors (including GaP Schottky)
• InGaAs and InP PIN photodiodes
• InGaAs/InP epitaxial wafers
Silicon photodetectors (standard 400nm to 1100nm and new UV/Blue Enhanced 365nm – 1100nm):
photovoltaic, photoconductive photodiodes, and phototransistors. Marktech’s silicon phototransistors can be
utilized in applications requiring very high sensitivity, uniform response, and increased reliability such as card
readers and optical sensors.
Silicon avalanche photodiodes (400nm to 1100nm, with 800nm, 905nm optimization).
Avalanche photodiodes (APDs) essentially provide an amplification gain stage through avalanche
multiplication. They are similar to photomultipliers but are solid state semiconductor devices. Avalanche
photodiodes are ideal for high-speed and low-light level detection in the near-infrared range. These
detectors have become the semiconductor equivalent of photomultipliers in many applications including
data communication, LIDAR, instrumentation, and photon counting. Marktech APDs have an internal gain
mechanism, fast time response, low dark current, and high sensitivity in the near-infrared region. These
APDs are recommended for applications that require high bandwidth or where internal gain is needed
to overcome high pre-amp noise. In addition, these devices provide higher sensitivity than standard
photodiodes and are ideal for extreme low-light level detection and short pulse detection.

UV detectors (150nm to 450nm). These devices use materials including GaP Schottky, GaN, and SiC.
A die can be packaged individually in a variety of hermetically sealed packages or multiple die can be
integrated in a custom package to suit your specific application. Marktech UV detectors offer superior
stability over time and high device sensitivity with low dark current.
• UV-A: Marktech also offers, on a custom basis, silicon-based UV detectors, which are designed for
operation in the UV-A range. These devices are available in plastic and surface mount packages in
addition to the standard TO metal can-type.
InGaAs PIN photodetectors (800nm to 2600nm).
These are high-sensitivity and high-reliability products, ideally suited for optical communication devices.
Chip active area sizes from 0.1mm to 3.0mm provide the optimum balance between low dark current, high
speed, and light sensitivity, allowing for increased flexibility and options in a variety of applications ranging
from fiber optics and high-speed optical communications to medical and chemical analysis. Marktech
manufactures InP PIN photodiodes using InGaAs/InP technology, which have a spectral sensitivity in the
800nm to 2600nm range for applications requiring low dark current, high speed, and sensitivity such as
fiber optics and optical communications. Marktech’s detector dice can be placed in a variety of packages
from metal can TO-5, TO-18, and TO-46 to surface mount and standard 3mm and 5mm plastic packages.
We can also incorporate the detector dice in custom-designed assemblies.
SWIR (Short Wavelength IR) Emitters (1050nm to 1720nm):
Marktech Optoelectronics is one of only a handful of manufacturers that supply emitters in the extended
wavelength or SWIR range. Marktech’s standard product offering includes both through-hole and surface
mount packages with wavelengths from 1050nm to 1720nm and operating currents ranging from 20mA
to 350mA for high-power applications. Higher wavelength ranges up to 3000nm are available in specific
package types. These detectors can be combined with a silicon sensor to cover the complete spectrum of
light from the visible to the SWIR range.
Marktech Custom Package Variations
Choose from any of the following package options when designing your custom emitter or detector
component. These packages are designed for accommodating 1 - 7 chips in any configuration. If you don’t
see a package that would work for your application, we can design a complete custom solution to meet your
needs.

Ceramic Surface Mount Package with no added lens

Plastic 6-leaded Surface Mount Package with no added lens

8 Pin, TO-39 Metal Can Package with multiple lens options

5mm ceramic stem with drip lens encapsulation
These versatile parts allow mix and matching of multiple emitters and multiple detectors.
Reflective Sensor Package for both emitters and detectors
Custom designs are available for variations off of Marktech standard Photo Reflectors. Typically standard
parts are offered in a compact high reliability 4mm plastic package with a wavelength range from 468nm
to 950nm and optimal operational distance is 0.5mm-1.5mm. These devices offer superior alignment and
sensitivity making them ideal for position sensing applications. Emitter/detector combinations are available
from UV to SWIR.
Custom- COB (Chip-On-Board) mounting to FR-4 boards, metal core PCBs, and ceramic and flex
Polyimide – up to 144 die on a single substrate.
In the late 2000’s, a push for even greater efficiency and increased density for LEDs was occurring, once
again, primarily driven by the lighting and general illumination market. This resulted in the widespread

introduction and usage of COB (Chip-On-Board) technology. COB is a semiconductor technology where
the “chip” also referred to as the “die” is mounted directly on the printed circuit board using a procedure
called die attach or die bonding. The individual die are placed on the PCB by either using a conductive
paste or soldering (Eutectic) method and then wire bonded. This technology virtually eliminates the need
for additional packaging such as lead frames and housings which allows for greater thermval dissipative
qualities, reduced size and increased LED density (if required).

140pcs of a LED chip packaged into an area less than 1 square inch
There are still challenges with using COB technology especially from a manufacturing standpoint. Some of
these include:
1. Capital expense - The equipment required is often very specialized and expensive
2. Uniformity and consistency is critical in many COB applications, therefore, the bare Die / Chip must be
carefully selected and tested prior to placement on the PCB. This process also requires very specialized
equipment and in addition, the yields must be considered to maintain a cost effective device.
3. Re-Work of COB assemblies can be difficult if already encapsulated. In some cases, the entire product
must be discarded. If the product is able to be re-worked, typically, it can only be performed at the
factory. Conversely, if the device is not encapsulated, re-work is relatively easy to perform compared to
through-hole and SMT technology and less costly.
4. The quality, uniformity and type of the PCB is critical to insure proper die attach and wire bond integrity.
Pure, wire-bondable gold is often required if Direct Attach or Flip Chip techniques are not used.
COB technology is now being used by almost every major LED manufacturer, primarily in the general
illumination and lighting marketplace. The increasing demand for energy efficient solutions to incandescent,
halogen and similar antiquated technologies is allowing for rapid growth in the COB LED arena. As this
technology continues to improve and costs decrease, the COB LED assembly market is expected to exceed
the overall standard LED market in the next several years. Although most manufacturers are focused on
energy efficient solutions to general illumination, there are a few select LED manufacturers (Marktech
amongst them) who are using the many advantages of COB technology in more niche, highly specialized
applications such as military, medical, machine vision and security.
An offshoot of COB technology which further increases efficiency and provides an even greater opportunity
for miniaturization are the Direct Attach and Flip Chip methods of assembly. Both methods do not require
wire bonding thus allowing for a lower profile COB assembly while improving performance. Currently, a
limited number of LED manufacturers (including Marktech) are taking advantage of this type of die structure.

In addition, there are even a smaller number of assemblers that are capable of properly mounting this type
of die. A major supplier of Direct Attach (DA) dice is Cree, Inc. An example of one of their DA type chips is
shown here.
Direct Attach (DA) die top and bottom view
The Direct Attach technique uses a flux eutectic bonding process which eliminates the need for solder paste,
preforms or conductive adhesives. An appropriate flux and PCB is all that is required to achieve a high quality
bond during the re-flow process. An example of an assembly made with standard COB technology versus
DA bonding is shown here.
Standard COB assembly (Wire Bonding Required)
Direct Attach assembly (No Wire Bonding Required)

Flip chip technology flips over the LED in a face down orientation and places the electrodes in direct contact
with the PCB. Like the Direct Attach process, this technology gives LED chips advantages that include
a larger light-emitting area, better heat dissipation, along with eliminating the wire-bonding step and
wire bond shadowing. The bonding method for flip chip die uses solder bumps. The attachment process
consists of applying the appropriate type of flux (as in the DA method) to these solder bump areas and then
performing a reflow process.
Due to the CTE (Coefficient of Thermal Expansion) mismatch between the flip chip and PCB, it is typically not
recommended to use FR-4 material but a ceramic or optimized MC (Metal Core) substrate PCB.
Flip Chip top view, bottom view and side view w/solder bumps
Both of these technologies are making large inroads into the general illumination and niche marketplaces
mentioned previously. In addition to some of the advantages described earlier, the reduction in thermal
resistance going from a through-hole device to COB will result in significant improvements in the lifetime
and performance of the product.
Custom-Varied layouts
Star boards
Starboards can be made with either die or surface mount components. Materials include FR-4, ceramic and
metal core. Standard boards are made for soldering wires, however connections may also be integrated for
quick and easy testing. In addition, these evaluation boards can be designed with thermal pads as well as
added components such as thermistors for performing temperature analysis.
Marktech’s Cree star and linear evaluation boards provide a solution for lighting designers and
manufacturers who want to test and measure Cree Xlamps®. Marktech offers Cree high-power Xlamps, as
well as UV and infrared emitters, on aluminum core star boards for easier product evaluation in a variety of
applications. Available in numerous colors or even multi-colors, and with several different viewing angles,

these single LED star board configurations are offered to designers as a tool to accelerate the adoption of
LED technology in designs that currently use another type of illumination. Additionally, Marktech can design
and develop custom assemblies incorporating high-power components.
Linear boards
Linear Boards are similar to the Starboards with the exception that they can be manufactured in multiple
widths and lengths.
Marktech’s evaluation boards provide a solution for lighting designers and manufacturers who want to test
and measure Cree Xlamps®. They help new designs get to market fast by reducing the time to prototype
and characterize luminaires. Marktech offers these standard and customizable solutions, while Cree delivers
the industry-leading LED technology.
Multi-Chip metal cans
Multi-Chip metal cans flexibly hold up to 7 chips of your choosing, in hermetic packaging as an alternative to
5mm ceramic stem packaging (see above).

Light Rings
If your application requires high reliability and high radiant power output, but needs a compact circular
footprint, a light ring may be the right LED solution for you.
Available in FR-4, metal core, and ceramic, light rings from Marktech push the boundaries in terms of chips,
materials, and sizes. Marktech currently produces one of the smallest commercially available light ring for
endoscopy applications at 4mm.

Additional custom designs:
If you don’t see a package that would work for your application, we can design a complete custom solution
to meet your needs.
Useful references:
Advanced Packaging of Optoelectronic Devices, Wiley Encyclopedia of Electrical and Electronics Engineering.
Published Online: 18 JAN 2013. Copyright © 2013 John Wiley & Sons, Inc.
Epoxies for OptoElectronic Packaging; Applications and Material Properties, by Michael J. Hodgin of Epoxy
Technology, Inc. Proceedings of the 36th Annual IMAPS Conference, Boston MA, Nov 17-20, 2003, pp. 26 -
30
Shining a light on LED technology, by M. Simard-Normandin of MuAnalysis
IWLPC (Wafer-Level Packaging) Conference Proceedings
http://www.smta.org/led/SMTA-Webinar-2015-03-19_Shining-a-light-on-LED.pdf
http://www.smta.org/chapters/files/Carolinas_Cree_The_Good_Bad_&_Ugly_on_LED_-_SMTA_Carolinas_
Expo_May_2015.pdf
Reconstituted Big-Chip LEDs on Multi-Layer Interconnects for High-Brightness Lighting. Authors: Liang
Wang, Gabe Guevara, Grant Villavicencio, Roseann Alatorre, Hala Shaba, Rey Co, Eric Tosaya. Company:
Invensas Corporation. Date Published: 11/11/2014 Conference: IWLPC (Wafer-Level Packaging)

Design, Testing, and
Binning

Utilizing our 30 years of engineering and marketing experience in optoelectronics, Marktech’s customization
process focuses on customer needs and applications. Instead of using standardized–but perhaps non-
optimized–parts, Marktech allows advantageous custom product variations to enhance your product
design needs. Marktech Optoelectronics has solved challenging LED design, assembly and manufacturing
problems for a wide range of customers. Marktech’s company size and market focus allows it to offer
customized variations of products that are not available from typical optoelectronic suppliers.
Resources are provided for component selection, packaging options, testing and expert advice, providing the
designer with insights concerning custom variations that can be leveraged to optimize electrical, optical, and
thermal characteristics–without the need for large volume commitments.
For a quick video of this, see: https://www.youtube.com/watch?v=8LDWuMejJv0
Design
Marktech has the design and test expertise you need to get your product to market faster, working with you
every step of the way from prototype testing to high volume production.
What you can expect from working with Marktech:
Initially, our staff of experienced engineers will gain an understanding of your application and the
environment in which it will be used.
In this fourth installment in our five-part series on Marktech’s
customization capabilities, we focus on examples of
Marktech’s equipment and facilities that are used to help
design, test, and bin your optoelectronic custom parts.

Next, using computer aided design, specialized software, and engineering tools, we operate within the
parameters of your primary concept and specification documents to design and develop a product that
meets your requirements.
Test Services
Once a prototype of your product is created, testing can begin in our onsite components lab. Testing is
supported by a complete onsite components lab with measurement capability for validation of wavelength,
angles, simulation of specific conditions, and full optical and electrical parametric characterization.
Optical measurements can be obtained either “Photometrically” or “Radiometrically” as described below.
Marktech’s application support also includes electrical parameter test, environmental test screening, and
reliability testing for your specific needs.
Photometry
Photometry is simply the measurement of light in the visible spectrum (approximately 380nm-770nm). This
is light seen by the naked eye of an average human observer. There are many different types of photometric
units such as nits (cd/m2), lux (lumen/m2), footcandles (lumen/ft2), stilb (cd/cm2) etc. All of these are based
on two basic photometric standards, the LUMEN and the CANDELA.
The Candela is the unit of luminous intensity, which can be defined as the amount of luminous flux (total
luminous power emitted from a source and expressed as lumens) per unit solid angle in a given direction.
The Lumen can be defined as the luminous flux emitted per unit solid angle from a uniform point source
whose luminous intensity is 1 candela. (1 candela = 1 lumen/steradian) It is also important to understand the
definition of steradian, which is the solid angle (cone) at the center of a sphere of radius “r” that subtends
an area “r2” on the surface of the sphere. (See figure 1) The surface area of a sphere is 4πr2; therefore, a
sphere has 4π steradians.

Figure 1
Radiometry
Radiometry refers to total radiation or the measurement of all light whether in the visible, infrared, or
ultraviolet spectrum. The basic unit of radiometric optical power (Radiant Power) is the watt (W). The watt is
an absolute unit because it is independent of wavelength. One watt of infrared light contains as much power
as one watt of visible light. Other radiometric terms that are commonly measured are radiant intensity
(Watts/Steradian), Irradiance (W/m2) and Radiance (W/m2 sr). The primary method for measuring total
radiant power/luminous flux is by using an integrating sphere.(See figures 2 - 5)
Integrating Sphere
The integrating sphere measures light emitted from the LED in all directions. Generally these measurements
are independent of viewing angle and not subject to angular measurement inaccuracies seen when testing
photometrically, however, errors are still possible. Sphere diameters of approximately 3 and 6 inches are
widely used. If accuracy is critical, the larger diameter types are preferred due to the favorable ratio of
the sphere area to the size of the LED and ports, however, this also results in a loss of intensity. A major
source of measurement error has been where to position the LED inside the integrating sphere. The latest
specification adopted by the CIE , Publication 127, states that the entire package of the LED should be inside

the sphere which is called a luminous flux measurement.
Figure 2 : Power output selection for 5mm red LED product
Figure 3: Optical parameter testing

Figure 4: Photo Research combination Photometer/ Spectroradiometer equipment, utilized for spectrally based
colorimetry and high speed, low level luminance testing
Figure 5: Light/power output characterization of finished custom devices
Reliability of LED Components and Assemblies

There are many factors that affect the reliability and lifetime of optoelectronic devices and assemblies.
Marktech insures that all product designed, prototyped and manufactured undergoes rigorous testing and
screening to insure optimal performance and life. Some of these conditions are outlined below.
Temperature Conditions of LEDs
It may be useful to calculate such information as the longevity characteristics (at high temperatures, normal
temperatures, and low temperatures) of a discrete LEDs in an environment in which the equipment will be
actually used, and to test those calculations by test operation of the equipment.
Humidity Conditions of LEDs
Depending on the material used in an LED, operating the LED under high-humidity, high-temperature
conditions can dramatically reduce its lifetime. When an LED may be used under high-humidity, high-
temperature conditions, be sure to check its longevity characteristics.
Current Conditions of LEDs
Because lattice defects increase with use, the luminous intensity of LEDs gradually declines. The speed of
accumulation of lattice defects depends on the magnitude of the forward current.
Others Factors of LEDs
When using a LED under conditions where factors such as vibration, shock, gas, or ultra-violet affect the
leads or resin, Marktech recommends testing the LED separately for each potential affecting factor.
LED Lamp Temperature Cycle Test
Temperature cycle testing is normally performed on the LED lamp structure at the upper-limit storage
temperature and the lower-limit storage temperature.
Longevity Simulation
The following examples show how simulation can be used to obtain longevity information. For simplicity
the characteristics of a hypothetical LED lamp are used. Example (a): Simulate the longevity of an LED lamp
incorporated in control equipment installed in a room in which high-temperature equipment is operating.
Environment
High-temperature equipment operates for 1,080 hours a year (three hours a day x 360 days) with a forward
current of 20 mA
LED lamp ambient temperature is 60°C, 60 days per year, humidity=”90%”

LED lamp longevity characteristics: Figure 6 shows the longevity characteristics of LED lamps.
REL Luminosity vs Time
Figure 6
Simulation Example
Calculating the LED lamp operating time per year by ambient temperature.
Condition 1 operating time: 3 hours x 60 days = 180 hours
Figure 7 shows the results. In the example, the longevity characteristics are simulated by the approximate
equation exp(-8 t), with 8 changing each time. Where the curve time constants for the characteristics in
Figure 6 are 81, 82, 83 and luminosity reduction rate = exp (-8nt), the calculation is made by assigning 8 to

each operating time.
Note: It is not possible to represent all the different longevity characteristics by a single approximate
equation. It would be risky to extrapolate the characteristics over ten or 20 years based on the above
examples and except the results to be accurate, even if the daily operating time were short. REL Luminosity
Residue vs Time 1
Figure 7 - Simulation example
Recent improvements have reduced the tendency for LED lamp luminosity to decline with use. The results
of long-term studies of longevity characteristics now show that the luminosity need not always attenuate.
The decline in luminosity that occurs during use has been evaluated using a Wiebel distribution function.
Sometimes, even after thousands of hours of longevity testing, the M-value does not change thousands of
hours (see Figure 8).
REL Luminosity Residue vs Time 2
Figure 8 - Predictions from longevity test results (a), (b), (c)
With the tendency for luminosity to deteriorate already confirmed by the results of long-term longevity
tests in Figure 8(a) and (b), longevity can now be predicted relatively easily. However, in Figure 8 (c), no
deterioration is seen, even after 10,000 hours of use. It is not possible to decide whether deterioration
proceeds in the (c-1) direction or the (c-2) direction. In some cases, the deterioration in the M-value is large
after a certain point, as in (c-2).

The absence of luminosity reduction during longevity tests does not mean that the LED lamp will not
deteriorate at some point in its life. When determining the location in which a piece of equipment
incorporating an LED is to be used, if necessary perform longevity testing under accelerated conditions, so
as to predict the longevity characteristics based on the actual conditions of use.
Tenney (Thermal Product Solutions) Temperature/ Humidity
Test Chambers. Typically used for 85C/ 85% Relative Humidity rigorous environmental component life
testing. Electrical bias testing is optionally included.
Quality inspection of bare dice on blue nitto (sticky) tape

Visual product inspection and documentation
Team evaluation of custom product
Quality inspection of a scoreboard product’s panel

100% Burn-In of flexible strips for architectural lighting
Burn In of flexible strip displays used for auto gas station pricing signage
Testing and Evaluation
By utilizing Marktech’s value-added engineering services, you will get a custom component or assembly
that meets your unique specifications. We provide our customers with extensive testing and evaluation
capabilities, ensuring your product is functioning exactly as expected.
Marktech’s testing and evaluation services include:
• Burn on
• IV / power output sorting
• Vf forward voltage / Vr reverse voltage testing
• Current gain sorting
• Wavelength sorting
• Angular measurements

• CCT and chromaticity coordinates
• Prototype capabilities
• Failure analysis
• Microscopic inspection
• Detector Spectral Response
• Detector efficiency
• Capacitance
• Dark Current
Machine Vision Lighting
Marktech offers unique lighting solutions when it comes to machine vision lighting. To begin with we design
our own printed circuit boards and specify the material composition since this is critical for proper die attach
and wire bonding of the bare die. We also have the ability to sort +/- 1 nanometer on the die or luminosity
and power output ratios of less than 2 to 1. Of great interest to our customer base is the fact that we can
guarantee uniformity of light across large surface areas. Marktech can assist you in making the transition
from thru-hole to chip on board. From initial concept through final product which includes the housing,

Marktech can help take the stress out of achieving maximum lighting for your machine vision application.
• State of the art designs incorporating chip on board
• Tight sorting options +/-1 nm
• Housing design and manufacturing
• High reliability
Proprietary advanced inspection equipment
High speed LED insertion

Machine vision inspection system
White LED strips and panels

Star Board solder paste process
Customized optical package design

Customer service
Customer service is a top priority at Marktech. So, even after delivery, our team will stay in touch to make
certain that your products are performing as expected.

Getting Started

Utilizing our 30 years of experience in optoelectronics, Marktech’s customization process focuses on
customer needs and applications. Instead of using standardized–but perhaps non-optimized–parts,
Marktech allows advantageous custom product variations to enhance your product design needs. Marktech
Optoelectronics has solved challenging LED design, assembly and manufacturing problems for a wide
range of customers. Marktech’s company size and market focus, along with 30+ years of engineering and
marketing experience, allows it to offer customized variations of products that are not available from typical
optoelectronic suppliers.
Resources are provided for component selection, packaging options, testing and expert advice, providing the
designer with insights concerning custom variations that can be leveraged to optimize electrical, optical, and
thermal characteristics–without the need for large volume commitments.
Customized assemblies
Customized assemblies can provide prototypes for what-if product builds, evaluation test products, and
products incorporating specific emitter and detector chips needed for demanding customer applications.
In this fifth installment of our five-part series on Marktech’s
capabilities, we focus on the overall steps that can be used to
provide customization as a solution for your application needs.

Pursuing a Custom Device
To develop a custom device that solves your needs –from proof-of-concept to manufacture and launch,
Marktech engineers will discuss with you these following areas, which are detailed further below:
Application support for needs specific to your project
Component optimization recommendations involving technology selection (see Product Selector Guide) and
assembly packaging, including:
Emitter selection (Cree and Marktech UV, visible, and NIR /SWIR chips)
• High-brightness and high-power LEDs
• Multichip emitters and chip-on-board packaging
• Infrared, ultraviolet, and visible LED emitters
• Single or multi-chip LED packages or modules for multiple wavelength applications
• Single or multiple LED die configurations
Detector selection (photo transistors, and photodiodes with the ability to detect light in the UV,
visible, and infrared spectrums)
• Specialty photo detectors (GaP Schottky)
• Standard photovoltaic silicon photodiodes
• Silicon photo transistor and Avalanche photodiodes
• InGaAs and InP PIN photodiodes
• InGaAs/InP epitaxial wafers
• Custom detectors from Marktech are also available through Digi-Key by filling out a form https://www.
digikey.com/en/supplier-centers/m/marktech-optoelectronics/custom-detectors
Packaging selection
• A variety of packaging can be selected, including:
• Ceramic surface mount package with or without an added lens

• Plastic 2, 4 or 6-leaded surface mount package with no added lens
• 8 pin, TO-39 metal can package with multiple lens options
• 2mm – 5mm ceramic stem with drip lens encapsulation
• Reflective sensor package for both emitter and detector
• Custom chip-on-board (COB) mounting to FR-4 boards, metal core PCBs, and ceramic and flex
polyimide
Test Services
Marktech’s application support includes electrical parameter test, environmental test screening and
reliability testing for your specific needs. Testing is supported by a complete onsite components lab with
measurement capability for validation of wavelength, angles, simulation of specific conditions, and full
optical and electrical parametric characterization.
Manufacturing
Complete turn-key manufacturing from Epi growth to finished products, and from pilot runs to full
production is available. Completed assemblies have ranged from two chips to 140, with no restrictions on
the number of chips we can mount. Whether your LED assembly needs are surface mount, through-hole,
or a combination of the two, we provide an efficient, hassle-free, cost-effective solution to LED assembly-
related challenges.

Application Support:
A discussion with our engineers about custom assemblies can answer these concerns:
• Does your application require multiple chips, either for emission or detection or both?
• What is the best material for your assembly: FR-4 to ceramic, flex, or metal core?
• How many chips are required based on output and drive conditions. (At Marktech, we have completed
assemblies ranging from two chips to 140, however, there are no restrictions on the number of chips we
can mount.)
• Is complete turn-key manufacturing needed? Marktech can supply this from Epi growth to finished
products.

Test Services
Marktech provides customized testing for your products. Unlike many optoelectronic device producers that
only will supply standard parts with standard testing, Marktech has the equipment, knowledge, procedures,
and most important—the willingness to custom test your parts as needed by you. Testing is done in
Marktech’s NY, California, and Japan facilities.
Test equipment includes:
• Photo Research
• Oriel Instruments (Newport)
• Labsphere
• Gooch and Housego
• Instrument Systems (Konica Minolta)
• Blue M (85/C/85%RH testing)
• Tenney (air to air thermal shock, and temperature cycling)
• Ransco (air to air thermal shock)
• UV to SWIR detector parametric test (utilizing customized equipment not available in the market)
• Spectral response
• Quantum efficiency
• Shunt resistance
• Dark current
• Bare emitter die test, with blue membrane tape (pick/test/replace die on tape), as well as waffle pack/
tray test.
Agilent / HP Parametric testing
Keithley electrical characterization
Manufacturing
With manufacturing facilities in California, Germany, and Japan, Marktech is a vertically-integrated company,
allowing quick production of components, thus decreasing your time to market. We can produce your entire
package in the United States, if need be.

LED Assembly Capabilities
• SMD, Thru-Hole & Chip-on-Board assembly
• High Density Pick & Place
• Prototyping
• High Volume Production Runs
• PCB Design and Fabrication
• Single or Multi-Layer
• Flexible or Rigid
• Aluminum, FR4 and Polyimide
• Eng. Software Capabilities
• Schematic Capture
• PCB Design
• Simulation
• CAD & CAM
• Consigned or purchased materials
• In-circuit testing
• GenRad functional testing
• Potting
• Conformal Coating
• IPC Standard Assembly
• Use of your Part Numbering System
• Shipped to your packaging requirements
• Additional Outsourced Capabilities Include:
• Plastic injection molding
• Metal work fabrication
To Get Started Marktech May Need
• Assembly drawing
• PCB FAB drawing and Gerber files
• Bill of Materials (BOM) with manufacturer’s name,
part numbers, and circuit references
• Drawings and BOM for any custom items; cable
assemblies, transformers, metal or plastic cases, etc.
• Is this consigned or turnkey material?
• Conformal Coating requirements
• Testing instructions
• Packaging requirements
• Target Costs
• Quantity and proposed delivery schedule
• Any existing vendors or special arrangements
Marktech needs to know about

Conclusion
Marktech offers our customers many options to achieve their goal of having a custom component or
assembly device designed to their specific needs. To accomplish this Marktech offers a wide selection of
emitter materials ranging from 280nm UV, the Cree line of visible materials, near IR, and SWIR materials.
Our range for emitter materials is one of the largest commercially available from one source and ranges
from 280nm to 2600nm with higher wavelengths available.
On the detector side we offer both silicon. GaP, and InGaAs materials. Available wavelengths begin at 150nm
(UV) through the visible range (440 to 700nm), near infrared (710 to 1050nm and Short Wave Infrared (1050
to 1720nm).
Our packaging options include both components and assemblies for emitters, detectors and a combination
of both. Packages include surface mount, multi-chip and chip on board. Design assemblies using ring lights,
starboards and linear boards to name a few.
We are able to test for any electrical and optical parameter for emitters and detectors. In most cases this
includes plus or minus 1 nanometer for emission.
For more information:
Contact Marktech Optoelectronics
3 Northway Lane, North
Latham, N.Y. 12110
Ph: 518-956-2980
E-mail: info@marktechopto.com
Fax: 518-785-4725
www.marktechopto.com

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