There is significant opportunity for improvements in contamination prevention, field performance and cost of medical devices through the use of biocompatible nanocoatings. To be successful using these coatings requires knowledge of the materials and processes on the market, the regulatory status, and the benefits versus risks. This presentation will provide a clear understanding of the current state of nanocoating technology for medical devices and electronics. There has been an explosion in new coating technologies over the past 24 months. The use of nanocoatings has been driven by the desire for moisture proofing, providing an oxygen barrier ( a hermeticity option) and mitigating tin whiskers. Successful adoption of these coating technologies can lead to improved performance and market differentiation. Inappropriate adoption can drive higher failure rates, recalls and alienation of customers. Obtaining relevant reliability and quality information can be difficult. The information is often segmented for different markets; and, the focus is on the opportunities, not the risks. The primary information sources are either marketing material or confusing, scientific studies. Where is the practical advice?

1. Using Nanocoatings:
Opportunities & Challenges for
Medical Devices
Cheryl Tulkoff, ctulkoff@dfrsolutions.com
Senior Member of the Technical Staff
DfR Solutions
November 12-13, 2013; Milpitas, CA.

2. • Introduction
• What is nanocoating technology?
• Super Hydrophobicity
• Atomic Layer Deposition
• Multi-Layer Barrier Films
• Who are the key players?
• What are the benefits?
• What are the risks?
• Summary
Topics to be covered

3. What is a medical device?
3
More diverse group than medical
electronics!

4. Medical Device Definition
 Surprisingly, no good, uniform definition of a medical device
 Increasing overlap in technologies combining medical devices with
biologics or drugs.
 Example: Drug-coated stents.
 How the device is regulated depends upon the primary function of the
product
 Since the stent is performing the primary function of holding a blood
vessel open, it is regulated in the US as a medical device
 If the primary function was to deliver medication, it would be regulated
as a drug
 This is an extremely complex area of regulation!

5. Medical Electronics – Still very
diverse!

6. What are medical electronics?
 Is it a realistic category?
 Some implanted in the body; some outside
 Some portable; some fixed
 Some complex; some simple
 Some control; some monitor; some medicate
 All connected by the perception that one’s life
may be dependent upon this product
 Creates a powerful emotional attachment/effect
 Assuring reliability becomes critical

7. Why are medical coatings used?
 Enhance performance of the device
 Extend useful life
 Cleaning, disinfection, and sterilization protocols
degrade product
 Protect the device
 Human body is a hostile environment
 Protect the patient
 Body responds to intrusions
 Defense mechanisms treat foreign objects as threats
 Reduce scar tissue and infection opportunities
 Encourage/enhance healing

8. Medical Coating Challenges
 Biocompatibility
 Coating adhesion
 Uniform coverage over challenging shapes
 Strength
 Durability

9.  Parylene-N and -C are currently approved by FDA
as a USP class VI polymer
 Allows them to be used in biomedical devices
 Parylene-C has higher thermal stability &
chemical/moisture resistance than Parylene N
 Commonly chosen as an encapsulation material for
biomedical devices
 Applications include stents, pacemakers, neural probes, and
solder joints encapsulation
 CVD Parylene can form a conformal and pinhole free coating
 Parylene films do not have strong adhesion to inorganic surfaces
such as silicon
State of Coatings in Implanted
Medical Devices
Reference” Characterization of Parylene-C film as an encapsulation material
for neural interface devices”

10.  Nonfouling (protein adsorption-resistant) thin-layer polymeric
coatings offer more paths to reduce inflammatory responses
 Surface coatings that completely eliminate protein adsorption
over the lifetime of a device have not been found
 Design requirements for implanted materials and devices vary
considerably
 Depends on the application and site of implantation
 Polymeric surface coatings for implantables ideally conform to
the following:
 Use nontoxic materials
 Prevent biofouling
 Can be deposited on a variety of materials and architectures
 Mechanical, chemical, and electrical stability to withstand
surface deposition, sterilization methods, implantation
procedures, and in vivo environment
Medical Device Coating Needs

11. Nanocoating Introduction
 Explosion in new
coating technologies
over the past 24
months
 Drivers
Moisture proofing
Oxygen barrier
(hermeticity)
Tin whiskers

12.  Super Hydrophobicity
 Atomic Layer Deposition
 Multi-Layer Barrier Films
Nanocoating Technology

13.  Definition: Wetting angle far
greater than the 90 degrees
typically defined as hydrophobic
 Can create barriers far more
resistant to humidity and
condensation than standard
conformal coatings
 How to get there?
 Deposit materials with existing high surface tension
(e.g., Teflon)
 Replicate the surface of the Lotus Leaf
Super Hydrophobicity

14.  Three companies currently focused on the
electronics market
 The key technology for each company is
the process, not necessarily the materials
Nano Deposition of High
Surface Tension Materials

15.  GVD: Founded in 2001. Spinoff from MIT
 Key technology is initiated chemical vapor deposition
(iCVD) and PTFE and Silicone
 P2I: Founded in 2004. Spin off from UK MOD
Laboratory and Durham University
 Key technology is pulsed plasma and halogenated
polymer coatings (specifically, fluorocarbon)
 Semblant: Founded in 2009. Spin off from Ipex Capital
 Key technology is plasma deposition and halogenated
hydrocarbon
Nanocoating Companies

16.  Hydrophobicity tends to be driven by number and
length of the fluorocarbon groups and the
concentration of these groups on the surface
 The key points to each technology are similar
 All assisted chemical vapor deposition (CVD) processes
 Room Temperature Deposition Process
 Low Vacuum Requirements
 Variety of Potential Coating Materials (with primary focus
on fluorocarbons)
 Differentiation is how they breakdown the monomer
before deposition
Process Technology

17. Process Differentiation
 iCVD uses a chemical
initiator to breakdown
the monomer
 Plasma-Enhanced
CVD (PECVD) uses
plasma to breakdown
the monomer
http://web.mit.edu/gleason-lab/research.htm
Courtesy of Semblant Ltd.

18.  These are truly nanocoatings
 Minimum Parylene thickness tends to be above
one micron (necessary to be pinhole free)
 These coatings can be pinhole free at 100 nm or
lower
 Nanocoating allows for
 Optical Transparency
 RF Transparency
 Reworkability
 Elimination of masking
Benefits (especially compared
to Parylene)

19. Optically Transparent
Courtesy of P2i

20. LLCR Measurements
Current (A) 0.01
V comp (V) 0.1
Connector Male 34way Pin Header Au over nickel contact (TE Connectivity 1-215307-7)
Connector Female 34way Socket Header Au over nickel contact (TE Connectivity 1-826632-7)
Benefits: No Masking
1
2
3
4
5
6
7
32
33
34
Current
Source
10mA
Nano
Voltmeter
34 way
header pins
34 way
header Socket
Rcontact = Vmeasure/10x10-3
Test Circuit
0
1
2
3
4
5
6
7
8
9
0 10 20 30 40
Resistance(mOhms)
Pin Number
Low Level Contact Resistance
Plasma Coated
Uncoated
Courtesy of Semblant Ltd.

21.  Voltage Breakdown
 Levels tend to be lower compared to existing coatings (acrylic,
urethane, silicone)
 Can be an issue in terms of MIL and IPC specifications
 Optically Transparent
 Inspection is challenging
 Cost
 Likely more expensive than common wet coatings
 However, major cell phone manufacturer claims significant ROI based
on drop in warranty costs
 Throughput
 Batch process. Coating times tend to be 10 to 30 minutes, depending
upon desired thickness
 However, being used in high volume manufacturing
Risks?

22.  Nanocoating technology is being used by
almost every major hearing aid
manufacturer (8 million per year)
High Volume Manufacturing
Courtesy of P2i

23.  P2i combats contamination and costly
sample loss through coatings for medical
devices & laboratory equipment
 Semblant developed Plasma Shield, a
conformal coating to coat electronic
components for internal medical devices and
equipment
 GVD provides protective coatings for medical
electronics, biocompatible coatings on
implantable devices, & lubricious coatings for
tubes and trocars.
Manufacturing for Medical

24.  High aspect surfaces create very high
(>150o) wetting angles
 Rapid adoption in other
industries
 Paints, clothing, etc.
 Challenges with electronics
 Different surfaces/chemistries can
disrupt surface modification
Where are Lotus Leaf
Coatings?

25.  Developed in the 70s and 80s
 Sequential surface reactions
 Deposition rate of ~0.1 nm/cycle
Atomic Layer Deposition (ALD)
Deposit
organometallic /
hydroxyl compounds
Purge
Treatment to react 1st
precursor (2nd
precursor or energy)
Purge

26.  Designed for inorganic
compounds
 Primarily simple
oxides and nitrides
 Limited industrial acceptance
 Electroluminescence displays (obsolete)
 Basic research
 Glass strengthening
 Considered for next-gen silicon
 Interest from solar
 Moisture / oxygen barriers
ALD (cont.)

27.  Advantages
 Deposition at low temps
(80-150C)
 Not line of sight (conformal)
 Precise thickness control
 Large area
 Less stringent vacuum requirements (0.1 – 5 mbar)
 Multilayer and gradient capability (it can be tailored)
 Northrop Grumman / Lockheed Martin estimated
cost reductions of 50% vs. traditional hermetic
approaches
ALD (cont.)
Atomic Layer Deposition (ALD) Coatings for Radar Modules, DMSMS 2012

28.  The process can be very slow
(100nm thickness can take over an hour)
 Not reworkable
 There have been challenges in regards to
compatibility of ALD with existing electronic
materials and manufacturing process
 Clean surfaces with similar coefficient of thermal
expansion (CTE) work best
 De-adhesion and cracking sometimes observed when
applied to metals, polymers, and surfaces with flux
residue (requires some tailoring)
Risks

29.  A Multi-Layer Barrier Stack to retard water vapor and
oxygen diffusion
 Patent history includes
Osram, filed in 2001
 Similar patents filed by
Battelle Labs and
commercialized by Vitex
Systems in 1999 (Barix) (now
Samsung America)
 Flexibility and transparency
key attributes of the technology
 Index matching of materials (primary driver is organic
LEDs and thin film solar)
Multi-Layer Barrier Films: What
is the Technology?

30.  Oxide barrier layer protects against oxygen and moisture
 Can be aluminum oxide, silicon oxide, or silicon nitride
 Polymer layer provides adhesion, smooth surface, decouples
defects
 Three to four layers required to survive 60C/90%RH for 500 hrs.
 Requires permeation less than 10-6 g/m2/day
Multi-Layer Barrier (cont.)
3 um total thickness

31.  Requires a low temp vacuum deposition process (PVD
or CVD)
 Concerns about cost and throughput (similar to parylene)
Multi-Layer Barrier Manufacturing Process
Vitex Process

32.  Recent advances use nanotechnology to
eliminate defects
Nanoparticles seal defects
and react/retain oxygen
and moisture
Requires fewer layers to
be effective
Claims up to
2300 hours
at 60C/90%RH
Multi-Layer Barrier Advances

33.  Multi-layer barrier is believed to be the only
solution for OLEDs
 However, commercialization has been limited
 Developed over ten (10) years ago; still not in
commercial production
 Only one or two manufacturers in this space
 Cost could be high (similar to parylene) and
potential for low throughput (batch process)
 Rework is likely impossible
Risks

34.  There is significant opportunity for field
performance improvement and cost reduction
through the use of nanocoatings
 Requires a knowledge of the materials and
processes on the market
 Benefits vs. Risks
 With any new technology, do not rely on standard
qualification tests!
 A physics-based test plan provides the most robust
mitigation
Conclusion

35. Presenter Biography
 Cheryl has over 22 years of experience in electronics manufacturing focusing on failure
analysis and reliability. She is passionate about applying her unique background to enable her
clients to maximize and accelerate product design and development while saving time,
managing resources, and improving customer satisfaction.
 Throughout her career, Cheryl has had extensive training experience and is a published author
and a senior member of both ASQ and IEEE. She views teaching as a two-way process that
enables her to impart her knowledge on to others as well as reinforce her own understanding
and ability to explain complex concepts through student interaction. A passionate advocate of
continued learning, Cheryl has taught electronics workshops that introduced her to numerous
fascinating companies, people, and cultures.
 Cheryl has served as chairman of the IEEE Central Texas Women in Engineering and IEEE
Accelerated Stress Testing and Reliability sections and is an ASQ Certified Reliability
Engineer, an SMTA Speaker of Distinction and serves on ASQ, IPC and iNEMI committees.
 Cheryl earned her Bachelor of Mechanical Engineering degree from Georgia Tech and is
currently a student in the UT Austin Masters of Science in Technology Commercialization
(MSTC) program. She was drawn to the MSTC program as an avenue that will allow her to
acquire relevant and current business skills which, combined with her technical background,
will serve as a springboard enabling her clients to succeed in introducing reliable, blockbuster
products tailored to the best market segment.
 In her free time, Cheryl loves to run! She’s had the good fortune to run everything from 5k’s to
100 milers including the Boston Marathon, the Tahoe Triple (three marathons in 3 days) and
the nonstop Rocky Raccoon 100 miler. She also enjoys travel and has visited 46 US states and
over 20 countries around the world. Cheryl combines these two passions in what she calls
“running tourism” which lets her quickly get her bearings and see the sights in new places.

36. Instructor Biography
 Cheryl Tulkoff has over 22 years of experience in electronics manufacturing with an
emphasis on failure analysis and reliability. She has worked throughout the electronics
manufacturing life cycle beginning with semiconductor fabrication processes, into printed
circuit board fabrication and assembly, through functional and reliability testing, and
culminating in the analysis and evaluation of field returns. She has also managed no clean
and RoHS-compliant conversion programs and has developed and managed
comprehensive reliability programs.
 Cheryl earned her Bachelor of Mechanical Engineering degree from Georgia Tech. She is a
published author, experienced public speaker and trainer and a Senior member of both
ASQ and IEEE. She holds leadership positions in the IEEE Central Texas Chapter, IEEE
WIE (Women In Engineering), and IEEE ASTR (Accelerated Stress Testing and Reliability)
sections. She chaired the annual IEEE ASTR workshop for four years and is also an ASQ
Certified Reliability Engineer.
 She has a strong passion for pre-college STEM (Science, Technology, Engineering, and
Math) outreach and volunteers with several organizations that specialize in encouraging
pre-college students to pursue careers in these fields.

37. Contact Information
• Questions?
• Contact Cheryl Tulkoff,
ctulkoff@dfrsolutions.com,
512-913-8624
• askdfr@dfrsolutions.com
• www.dfrsolutions.com
• Connect with me in LinkedIn as well!