LTCC Passive Integration
Status and challenges

Steve Dai, Motorola Labs, Tempe, Arizona




             Channel/
              cavity



            Embedded
             Capacitor
Outline


• Introduction
• LTCC (Low Temperature Cofired Ceramics)
     –   LTCC materials
     –   LTCC Passive integration
     –   LTCC feature forming
     –   Zero shrink tape: ideal way for integration?
• LTCC Applications
     – Wireless
     – Automotive, energy and others
• Summary


Steve Dai, SICCAS LTCC Seminar   7_16_2007
Introduction
Why Passive Integration?


• Device miniaturization
• Greater component density for increased functionality
• High speed signal process requires
     – Lower equivalent series inductors
     – Tighter control of parasitic R, C and L
• Higher assembly yield
• Lower system cost
• Better reliability



     * Robert Heistand, ED Online #2718, Feb 2, 2003

Steve Dai, SICCAS LTCC Seminar    7_16_2007
Introduction
Paths to Passive Integration – technologies

               Characteristics                  PCB (Printing            LTCC                Thin film on
                                                Circuit Board,          (MCM-C)                Si/glass
                                                   MCM-L)                                     (MCM-D)
        Substrates                              FR-4, BT, FR-5           Ceramic           Si, Glass, Sapphire
                   Dielectric Constant (εr)      4.9 / 3.9 / 4.7           7 -12               12 / 5 / 10
                      Loss Tangent (1 GHz)      .015 /.009/.010         .0003 -.003         .005/ .003 / .0001
                        Thermal σ(W / m-K)           .2 -.4                 2.5               100 / 1.7 / 42
                                 CTE (ppm)        15 / 15 / 13              6                   2.6 / 1 / 8
                                 # of Layers           8                    30                      6
        Conductors                                    Cu           Ag, Ag/Pd, Au, Pt, Cu       Al, Cu, Au
                      Electrical ρ (10-8 Ω-m)         1.7                 1.2~1.7             2.6 / 1.7 / 2.1
                         Thermal ρ (W/m-K)            398                398~428                247~398
                           Line Width (μm)            100                   75                      5
        Process Variation                          10 -15 %               2 –4 %                 2 –4 %
        RF Frequency                               < 10 GHz              <25 GHz                < 50 GHz
        # Iterations to Spec                           5                    5                       5
        Iteration Time                              1 week               2 weeks               2-4 weeks
        Iteration Cost1                              $.5 K                 $2 K                   $10 K
       * From INEMI

Steve Dai, SICCAS LTCC Seminar   7_16_2007
Introduction
Paths to Passive Integration – a comparison

       Technology                    Integration                 Advantages                  Disadvantage
                                     method
       Thin film on                  Lithographically defined
                                        L/C/R
                                                                 Precision L/C/R value       Low inductance
                                                                 High tolerance              Equipment costly
       Si/glass                      Sequential build up of      High component density      Limited selection on film
                                        layers
       (MCM-D)                                                   Cost effective for dies <      materials
                                                                   20 mm2                    Materials compatibility

       Thick film on                 Screen printed L/C/R on
                                       sintered ceramic
                                                                 Low cost process            No precise Rs
                                                                 High packaging density      Ls difficult to form
       ceramics                        substrates (e.g. Al2O3)   Module reliability - auto   Process time and yield
                                     Sequential build up of
       (MCM-C)                         multiple layers
                                                                   applications                due to sequential
                                                                                               buildup

       PCB (Printing                 Discrete L/C/R buried in
                                       laminated structure
                                                                 Low cost process            Lack high K dielectric
                                                                 Multilayer structure        R limited, trimming
       Circuit Board,                Sequential or parallel      Cu conductor                PCB not RF friendly
       MCM-L)                          process                                               No CAD tool for PCB
                                                                                                passive layout

       LTCC                          Screen printed L/C/R on
                                       “green” ceramics tapes
                                                                 Parallel layer process      Cofireability of materials
                                                                 High layer counts~ 100      No high K dielectric
       (MCM-C)                       Parallel multi layer and    RF friendly materials       No precise Rs
                                       final cofired structure   Module reliability          Inductor limited
     * Robert Heistand, ED Online #2718, Feb 2, 2003

Steve Dai, SICCAS LTCC Seminar    7_16_2007
Introduction
LTCC market potential




    * From Paumonok, in millions of US$



LTCC market driven by RF wireless applications
     –   Loss conductors, Ag
     –   Temperature stable base dielectric, Tf ~ 0 ppm/°C
     –   Precision stack capacitor – resonator
     –   Fast turn around
     –   Infrastructure
     –   Competitive cost

Steve Dai, SICCAS LTCC Seminar      7_16_2007
Introduction
LTCC landscape
                                        US/CA                           EU                                                    JP                                    Asia - other




                                                                             Epcos, Selmic, TAHLES, VIT, IMST




                                                                                                                                   Soshin/NGK, Taiya Yuden, Nikko
            LTCC                         Motorola




                                                                                                                                                                         ACX (TW), Samsung EMCO,
                                                                                                                                      Nippon Electro Glass, etc
          Applications              Northrop Grumman
                                         Rockwell
                                           TDK
              LTCC                       Ford/GM




                                                       Bosch, Siemens




                                                                                                                 Hitachi, MuRata
              Design

              LTCC                     C-MAC, CTS
                                       Vispro, ATC
            Foundries                   CoorsTec


             LTCC                      DuPont, Ferro
            materials                  Hereaus, ESL




                                      Horizontal                                                                Vertical
Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Process Flow




Steve Dai, SICCAS LTCC Seminar   7_16_2007
Common LTCC Base Dielectrics




Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Base Dielectric
a comparison
                                             Green             Sintered

Type 1:
     Unreactive, glass as bonding
       agent
     Example: DuPont 951

Type 2:
     Re-crystallizeable, glass re-
       crystallize to form high Q
       phases
     Example: Ferro A6

Type 3:
     Reactive, glass as both bonding
       agent and ingredients for high
       Q crystalline phases
     Example: Motorola T2000
                                               Glass   Al2O3      Crystalline phase
Steve Dai, SICCAS LTCC Seminar   7_16_2007
Motorola T2000 LTCC Dielectric

     Existing system:               Glass: K2O, B2O3, SiO2     Ceramic Filler       Tf
     K=7.8                                 CaO, SrO, BaO           Al2O3         Adjuster
                                                                                  TiO2
     Q=500
     Tf=-60 ppm/°C
     Contains Pb
                                                          Sintering
                                                         850~ 900 °C



                                   Residual    CaAl2Si2O8, Q=1300         Al2O3
     T2000 dielectric:             Glass       SrAl2Si2O8, Q=1300-10000   Q = 10000
     K=9.1                         Q ~ 350     BaAl2Si2O8, Q=10000         VAl2O3
                                                                                      TiO2
     Q=1000                          Vglass               Vcryst.
     Tf~ 0 ppm/°C
     Pb-free
                                Dielectric    1= V Vglass Vcryst . V
                                                  i≈     +        + Al 2O 3
                                Mixture       Q ∑Q   350   1500    10000
                                                  i


              Calculated Q: ~ 1100, measured Q: 1050 - 1200

Steve Dai, SICCASA, 7/18/2007
T2000 TEM Microstructure




Al2O3 particles from 3 μm to <1 μm High Q phases formed in reaction
     Al2O3 dissolves/diffuses into glass     Particle size/S.A.
                                             Sintering T and t
                                             Heating rate




Steve Dai, SICCAS LTCC Seminar   7_16_2007
T2000 Temperature Stability
                                                                                                                   1.006
                                                      T f Measurement
                                  1.248                                                                                                                                    Tf Measurement
                                  1.246                                   TiO 2 added                              1.004
   Resonant frequency (10 9 Hz)




                                                                          No TiO   2
                                  1.244




                                                                                            Normalized Frequency
                                                                                                                   1.002

                                  1.242
                                                                                                                   1.000
                                   1.24
                                  1.238
                                          T f =4.2 ppm/°C                                                          0.998         T2000: 0.6 ppm/C
                                  1.236                                                                                          FerroA6: -48 ppm/C
                                          T f =-78.5 ppm/°C                                                                      DuPont 943: -58 ppm/C
                                  1.234                                                                            0.996         DuPont 951: -69 ppm/C
                                                                                                                                 Hereaus: -76 ppm/C
                                  1.232
                                          -40   -20     0    20      40      60        80                          0.994
                                                       Temperature (°C)                                                    -50    -30         -10         10        30      50     70       90
                                                                                                                                                         Temperature (C)




 Compensation of Tf (temp coef of resonant freq):
                                  Need negative Tk material, TiO2 (TK =-750 ppm/°C)
                                      Tf= -(1/2)Tk - α, α is thermal coefficient of expansion
                                  Tf of T2000 is -80 ppm/°C without compensation
                                  Can be continuously tuned near 0 ppm/°C
Steve Dai, SICCAS LTCC Seminar                              7_16_2007
T2000 TiO2 Distribution




        T2000 Quantitative Analysis: (wt%)
                         wTiO2    wAl2O3     wCaF2
        Ref 1            0        100        20
        Ref 2            30       70         20
        Ref 3            60       40         20
        Ref 4            100      0          20
        Sintered T2000 3.5        40.3       20
        Unfired T2000    6.2      49.1       20
Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Passive Integration
Embedded high K dielectrics

                                                                                               BZN Cofired in LTCC
    BZN high K dielectric


                                                                                                           Ag
        Dielectric properties of low fire BZN                                                    K80


                                                                                                T2000
   “Higher K Low Loss Dielectric Ceramic Cofireable with a Commercial LTCC Tape System”,
   Weiming Zhang, J. Thomas Hochheomer, Christina Modes, Peter Barnwell and Steve Dai, IMAPS
   annual meeting, Oct. 2001, Baltimore, USA. To be published on IMAPS proceedings.
                                                                                                           10 μm


     Critical:
     Lower sintering from 1050 to 850 C with 0.5~3.0 wt%
      glass

Steve Dai, SICCAS LTCC Seminar       7_16_2007
LTCC Conductors
Common conductors and Ag/Pd paste
                                                                       20

                                                                       15
    Observation




                                             Dimentional Change (%)
                                                                       10
    • Glassy sintered surface                                           5
      with mixed Ag/Pd                                                  0
      conductor                                                        -5
                                                                                         Dieletric
    • No surface glass                                                -10                Ag/Pd alloy
                                                                                         Ag/Pd mixture
      observed with alloy                                             -15
                                                                             * courtesy T. Garino - Sandia National Labs, Albuquerque, NM
      Ag/Pd                                                           -20
                                                                            300   350   400   450   500    550   600   650   700    750   800   850   900   950
                                                                                                          Temperaure (°C)


                                                                                              Ag: 962 ºC                           Pd: 1772 ºC
       Unusual large expansion in
       Ag/Pd mixture in 350-400 ºC.

       Kirkendall Effect?



Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Passive Integration
Embedded resistor
                                                                 RuO2 based
         Screen                              Direct
                                                                 embedded resistor
         print                               write
                                                      to


       Dielectric properties of low fire BZN
                                                                                                      t




                                                           P. Yang, D. Dimos, M. A. Rodriguez, R. F.
                                                           Huang, S. Dai, D. Wilcox., MRS Proc 542 (1999)




Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Passive Integration
Embedded resistor in via




Steve Dai, SICCAS LTCC Seminar   7_16_2007   (Courtesy of F. Uribe et al., Sandia)
LTCC Passive Integration
integrated magnetic materials




       HeraLock with cofired ferrite         A. Feingold, et al., IMAPS 2001
       transformer, F. Lautenhiser and E.
       Amaya, ICAPS 2002



Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Integration
piezoelectric/piezoresistive Materials




                   PZT/LTCC membrane, W. Hermel, P. Otschik, A. Schonecker, Fraunhofer IKTS, Dresden




      Piezoresistive pressure sensor on                  LTCC membrane for integrated pressure
      LTCC. Sensitivity: 1.3 mV/kPa                      sensor, L Golonka, Wroclaw University
Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Passive Integration
Status



         Embedded L                          Embedded C               Cofired R
         (5 ~ 200 nH)
                                   Paste            Layer     Embedded     Surface
                                   (up to 25        (50~70    (10 Ω/sq ~   trimmable
                                   nf/cm2 with      pf/cm2)   100 kΩ/sq)   (10 Ω/sq ~ 1
                                   K800)                                   MΩ/sq)
                ± 5%                   ± 30%          ± 5%       ± 30%          ± 2%




Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Feature Forming
Critical sizes




Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Feature Forming
techniques




Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Feature Forming
microchannels
            Sintering cavity without fugitive material                                       M. R. Gongora-Rubio et
                                                                                             al.,Sensors and Actuators
                                                                                             (2001)




      Compensate sagging with supported structure




                                                           Integrated UV Light Source


        Controlled firing of fugitive carbon black paste




                                                            Dia. =150 μm                             V
                                                            Thickness = 110 μm
                                                            Gas: Ne                     G. Eden, B. Vojak, Univ. of
                                                            V = 100- 200 V              Illinois, Urbana, Illinois,
    (Courtesy of T. Garino, Sandia)                         I = 2 mA
Steve Dai, SICCAS LTCC Seminar        7_16_2007             Pressure = 200-800 Torr
LTCC Feature Forming
suspended structure
                                                                                   Antennae
          Suspended Inductors




                                     1 mm
                                     Unfired                          1 mm




                                      Fired
                                             K. A. Peterson et al., CICMT (2005)

Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Feature Forming
released moving parts

                                                            Pneumatically driven functional-as-
                                                            released wheels (3 mm)


                                       Setter as fugitive
                                       materials




                                                                   K. A. Peterson et al., CICMT (2005)
                                             Wheel free to
                                             rotate
Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Feature Forming
Unconventional Forming and Physical Insertion
 Ion Mobility Spectrometer                                                  Heated gas feed tube
                                             Rolled IMS drift tube
                                                                                             1 cm
                                                                               Thermistor
                                                                                            Contact
                                                                                            buried
                                                                                            heater



                                                        12 mm I.D.
                                                  K. A. Peterson et al., CICMT (2005)




   (Courtesy of K. A. Peterson
   and K. B. Pfeifer, Sandia)



Steve Dai, SICCAS LTCC Seminar   7_16_2007
Zero-shrink LTCC Tape
transfer tape



          Al2O3 tape                           Al2O3 tape   Al2O3
        LTCC Module                  Sinter   LTCC Module             LTCC Module
                                                            removal
                                               Al2O3 tape
          Al2O3 tape




Compatible lamination process
Limited LTCC layers
Require backend Al2O3 removal from surface
Post fire surface electrode patterns


Steve Dai, SICCAS LTCC Seminar   7_16_2007
Zero-shrink LTCC Tape
differentiate shrinkage




               By W. Wersing et al., Siemens

Steve Dai, SICCAS LTCC Seminar   7_16_2007
Zero-shrink LTCC Tape
Heralock HL2000 (courtesy of Hereaus)




                                             Full ground plane




    Needs no extra processing
    Virtually zero x & y shrinkage
    Very precise dimensional control
    Fires flat
    Cavities readily available
    Allows novel structures
Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Applications
RF building blocks

                                                                    ANT

                                                                      C7

                                                                           C8

                                                     Z1
                                                                                        Multilayer Capacitor
                                                                Z4


                                             C1           Z2   D1          Z3                     C4
                                      TX                                                               RX
           Vertically Coiled                  C2               C3                  D2
                                                                                             C5

          Transmission Line                                                     BIAS
                                                                                        C6




                     Metal
      Dielectric Paste                       Metal
                                                                                        Horizontally Coiled
                         Dielectric Tape                                                Transmission Line

               Dielectric Paste Capacitor
Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Applications
RF frontend modules




Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Applications
Wireless modules
         IMST radar sensor                   IMST transceiver
                                             module




  RF moduels, Micro Systems                  Kyocera PA module – size reduction via passive
  Engineering GmbH                           integration




Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Applications
automotive – slow yet stable growth
                                                 Bosch electronic turbo charger
• working temperature up to
  155°C
• high vibration stress up to 50g
• direct engine mountability
• high packaging density (Thick
  Film -> LTCC)
              Delphi Delco LTCC ABS controller   Delphi Delco LTCC ECU




Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Applications
Direct Methanol Fuel cell                                         Concept for Fuel Cell with integrated
                                                                        pumping and control




                    Gold
   Flow Field      Current          Air Holes
  (anode side)    Collector      (cathode side)




                                                                                 Working Fuel Cell
Steve Dai, SICCAS LTCC Seminar   7_16_2007
                                                  Assembled Fuel Cell
LTCC Applications
Micro cooling
                Heat pipes                            Heat spreader




                                                                                 layout of microchannels
                                                                                 grey: line + printed resistor,
                                                                                 black: cooling channel)




                                                                                Microchannel cooling
    Heat pipes formed with LTCC micro channels as heat spreader (Kinzy Jones,
    FIU)                                                                        (H. Thust, Ilmenau TU)
Steve Dai, SICCAS LTCC Seminar   7_16_2007
LTCC Applications
Optoelectronic packaging

                                                              WAVEGUIDE
                                                                                  Demodulator IC
                                                              Input/Output
                                       Integrated laser and
                                       optical modulator
                                                                                         ELECTRICAL
                                                                                          Input/Output
                Embedded optical   Photo detector
                switches
                                                                                                Coax cable
               Polyme r optical
               waveguide embedded in
               LTCC


       LTCC Fibre
       alignment
       groove

    Ball grid array mounting                                                            Transimpedance
                                                                                        amplifier (flip chip)

                                                                             Photo detector array               MEMS package with integrated
                                                                                  Embedded passives
                                                                                                                heaters and thermistors (L.
                                                               Silicon V-groove   (resistors/capacitors)        Golonka, Wroclaw U.)
                                        Multilayer LTCC
           Fibre Optic
          Input/Output                  substrate




                    CMAC’s System In a Package Vision

Steve Dai, SICCAS LTCC Seminar         7_16_2007
Summary
LTCC is powerful platform integration technology with wide applications
     Wireless applications is the fastest growth area

Material challenges:
      Base and integrated high K Dielectrics
      Improved Conductors (Au, Ag, Ag/Pd, Pt, Cu, etc)
      Precision cofired resistors
      Magnetic materials
      Functional materials (Ferroelectric, piezoelectric, magnetic, sensing, …)

Process Challenges
      Combination of tape and thick film processes
      Thin film process for fine feature forming
      Interconnect technologies
      Modeling on sintering of dissimilar materials

Integration and Assembly Challenges
     Application driven
     Technologically innovative
     Knowledge-based understanding

Steve Dai, SICCAS LTCC Seminar   7_16_2007
Backup slides
                         Methanol Reformer
                                                                                                         Cell Phone
                                                                                                         Receiver



                                 15 mm
                                                       fuel               integrated
ENERGY                                              reformers              modules
                                         5 mm
                                                       MICROSYSTEM                                WIRELESS
     Direct                                             FUNCTIONS on-chip                      COMMUNICATIONS
    Methanol                                                                         power
    Fuel Cell                                                                   ICs amplifiers
                                                  sensors
                                          fuel                 NEW
    Micro Hollow Cathode                  cells             MATERIALS &                  filters
                                                                                                                        8 mm

     Discharge (MHCD)                                       PROCESSES
                                                    light                        pumps
       UV light source
                                                  sources                                                     8.5 mm
                                                                                                     Power Amplifier
                                                        temperature       chemical
                                                                          reactors PCR
                                                  E-chip control                                                       Pumping/
                                                                                                                        Mixing

               V                                                cell sorting
    Integrated BioChip
    Technology                                          LIFE                                          DNA
Steve Dai, SICCAS LTCC Seminar     7_16_2007          SCIENCES                                     amplification
Backup slides


                                                                             ~
                                                                     ~


                                        LNA Bypass
        Impedance        Power and Bias Capacitors Bandpass Filter
          Matching
           Line
                                                         To
              Bias                                      Amplifier
              Circuit


               Trap                                      From
               Filter                                   Amplifier

                                                                         1 cm X 1 cm
         Switch w/
         Harmonic                                                        41 components/sq. cm
          Filter                                       To Mixer
                                   Switch Image Reject Filter
                  Transmit Antenna Bias
Steve Dai, SICCAS LTCC Seminar   7_16_2007

LTCC Overview

  • 1.
    LTCC Passive Integration Statusand challenges Steve Dai, Motorola Labs, Tempe, Arizona Channel/ cavity Embedded Capacitor
  • 2.
    Outline • Introduction • LTCC(Low Temperature Cofired Ceramics) – LTCC materials – LTCC Passive integration – LTCC feature forming – Zero shrink tape: ideal way for integration? • LTCC Applications – Wireless – Automotive, energy and others • Summary Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 3.
    Introduction Why Passive Integration? •Device miniaturization • Greater component density for increased functionality • High speed signal process requires – Lower equivalent series inductors – Tighter control of parasitic R, C and L • Higher assembly yield • Lower system cost • Better reliability * Robert Heistand, ED Online #2718, Feb 2, 2003 Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 4.
    Introduction Paths to PassiveIntegration – technologies Characteristics PCB (Printing LTCC Thin film on Circuit Board, (MCM-C) Si/glass MCM-L) (MCM-D) Substrates FR-4, BT, FR-5 Ceramic Si, Glass, Sapphire Dielectric Constant (εr) 4.9 / 3.9 / 4.7 7 -12 12 / 5 / 10 Loss Tangent (1 GHz) .015 /.009/.010 .0003 -.003 .005/ .003 / .0001 Thermal σ(W / m-K) .2 -.4 2.5 100 / 1.7 / 42 CTE (ppm) 15 / 15 / 13 6 2.6 / 1 / 8 # of Layers 8 30 6 Conductors Cu Ag, Ag/Pd, Au, Pt, Cu Al, Cu, Au Electrical ρ (10-8 Ω-m) 1.7 1.2~1.7 2.6 / 1.7 / 2.1 Thermal ρ (W/m-K) 398 398~428 247~398 Line Width (μm) 100 75 5 Process Variation 10 -15 % 2 –4 % 2 –4 % RF Frequency < 10 GHz <25 GHz < 50 GHz # Iterations to Spec 5 5 5 Iteration Time 1 week 2 weeks 2-4 weeks Iteration Cost1 $.5 K $2 K $10 K * From INEMI Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 5.
    Introduction Paths to PassiveIntegration – a comparison Technology Integration Advantages Disadvantage method Thin film on Lithographically defined L/C/R Precision L/C/R value Low inductance High tolerance Equipment costly Si/glass Sequential build up of High component density Limited selection on film layers (MCM-D) Cost effective for dies < materials 20 mm2 Materials compatibility Thick film on Screen printed L/C/R on sintered ceramic Low cost process No precise Rs High packaging density Ls difficult to form ceramics substrates (e.g. Al2O3) Module reliability - auto Process time and yield Sequential build up of (MCM-C) multiple layers applications due to sequential buildup PCB (Printing Discrete L/C/R buried in laminated structure Low cost process Lack high K dielectric Multilayer structure R limited, trimming Circuit Board, Sequential or parallel Cu conductor PCB not RF friendly MCM-L) process No CAD tool for PCB passive layout LTCC Screen printed L/C/R on “green” ceramics tapes Parallel layer process Cofireability of materials High layer counts~ 100 No high K dielectric (MCM-C) Parallel multi layer and RF friendly materials No precise Rs final cofired structure Module reliability Inductor limited * Robert Heistand, ED Online #2718, Feb 2, 2003 Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 6.
    Introduction LTCC market potential * From Paumonok, in millions of US$ LTCC market driven by RF wireless applications – Loss conductors, Ag – Temperature stable base dielectric, Tf ~ 0 ppm/°C – Precision stack capacitor – resonator – Fast turn around – Infrastructure – Competitive cost Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 7.
    Introduction LTCC landscape US/CA EU JP Asia - other Epcos, Selmic, TAHLES, VIT, IMST Soshin/NGK, Taiya Yuden, Nikko LTCC Motorola ACX (TW), Samsung EMCO, Nippon Electro Glass, etc Applications Northrop Grumman Rockwell TDK LTCC Ford/GM Bosch, Siemens Hitachi, MuRata Design LTCC C-MAC, CTS Vispro, ATC Foundries CoorsTec LTCC DuPont, Ferro materials Hereaus, ESL Horizontal Vertical Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 8.
    LTCC Process Flow SteveDai, SICCAS LTCC Seminar 7_16_2007
  • 9.
    Common LTCC BaseDielectrics Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 10.
    LTCC Base Dielectric acomparison Green Sintered Type 1: Unreactive, glass as bonding agent Example: DuPont 951 Type 2: Re-crystallizeable, glass re- crystallize to form high Q phases Example: Ferro A6 Type 3: Reactive, glass as both bonding agent and ingredients for high Q crystalline phases Example: Motorola T2000 Glass Al2O3 Crystalline phase Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 11.
    Motorola T2000 LTCCDielectric Existing system: Glass: K2O, B2O3, SiO2 Ceramic Filler Tf K=7.8 CaO, SrO, BaO Al2O3 Adjuster TiO2 Q=500 Tf=-60 ppm/°C Contains Pb Sintering 850~ 900 °C Residual CaAl2Si2O8, Q=1300 Al2O3 T2000 dielectric: Glass SrAl2Si2O8, Q=1300-10000 Q = 10000 K=9.1 Q ~ 350 BaAl2Si2O8, Q=10000 VAl2O3 TiO2 Q=1000 Vglass Vcryst. Tf~ 0 ppm/°C Pb-free Dielectric 1= V Vglass Vcryst . V i≈ + + Al 2O 3 Mixture Q ∑Q 350 1500 10000 i Calculated Q: ~ 1100, measured Q: 1050 - 1200 Steve Dai, SICCASA, 7/18/2007
  • 12.
    T2000 TEM Microstructure Al2O3particles from 3 μm to <1 μm High Q phases formed in reaction Al2O3 dissolves/diffuses into glass Particle size/S.A. Sintering T and t Heating rate Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 13.
    T2000 Temperature Stability 1.006 T f Measurement 1.248 Tf Measurement 1.246 TiO 2 added 1.004 Resonant frequency (10 9 Hz) No TiO 2 1.244 Normalized Frequency 1.002 1.242 1.000 1.24 1.238 T f =4.2 ppm/°C 0.998 T2000: 0.6 ppm/C 1.236 FerroA6: -48 ppm/C T f =-78.5 ppm/°C DuPont 943: -58 ppm/C 1.234 0.996 DuPont 951: -69 ppm/C Hereaus: -76 ppm/C 1.232 -40 -20 0 20 40 60 80 0.994 Temperature (°C) -50 -30 -10 10 30 50 70 90 Temperature (C) Compensation of Tf (temp coef of resonant freq): Need negative Tk material, TiO2 (TK =-750 ppm/°C) Tf= -(1/2)Tk - α, α is thermal coefficient of expansion Tf of T2000 is -80 ppm/°C without compensation Can be continuously tuned near 0 ppm/°C Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 14.
    T2000 TiO2 Distribution T2000 Quantitative Analysis: (wt%) wTiO2 wAl2O3 wCaF2 Ref 1 0 100 20 Ref 2 30 70 20 Ref 3 60 40 20 Ref 4 100 0 20 Sintered T2000 3.5 40.3 20 Unfired T2000 6.2 49.1 20 Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 15.
    LTCC Passive Integration Embeddedhigh K dielectrics BZN Cofired in LTCC BZN high K dielectric Ag Dielectric properties of low fire BZN K80 T2000 “Higher K Low Loss Dielectric Ceramic Cofireable with a Commercial LTCC Tape System”, Weiming Zhang, J. Thomas Hochheomer, Christina Modes, Peter Barnwell and Steve Dai, IMAPS annual meeting, Oct. 2001, Baltimore, USA. To be published on IMAPS proceedings. 10 μm Critical: Lower sintering from 1050 to 850 C with 0.5~3.0 wt% glass Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 16.
    LTCC Conductors Common conductorsand Ag/Pd paste 20 15 Observation Dimentional Change (%) 10 • Glassy sintered surface 5 with mixed Ag/Pd 0 conductor -5 Dieletric • No surface glass -10 Ag/Pd alloy Ag/Pd mixture observed with alloy -15 * courtesy T. Garino - Sandia National Labs, Albuquerque, NM Ag/Pd -20 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Temperaure (°C) Ag: 962 ºC Pd: 1772 ºC Unusual large expansion in Ag/Pd mixture in 350-400 ºC. Kirkendall Effect? Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 17.
    LTCC Passive Integration Embeddedresistor RuO2 based Screen Direct embedded resistor print write to Dielectric properties of low fire BZN t P. Yang, D. Dimos, M. A. Rodriguez, R. F. Huang, S. Dai, D. Wilcox., MRS Proc 542 (1999) Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 18.
    LTCC Passive Integration Embeddedresistor in via Steve Dai, SICCAS LTCC Seminar 7_16_2007 (Courtesy of F. Uribe et al., Sandia)
  • 19.
    LTCC Passive Integration integratedmagnetic materials HeraLock with cofired ferrite A. Feingold, et al., IMAPS 2001 transformer, F. Lautenhiser and E. Amaya, ICAPS 2002 Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 20.
    LTCC Integration piezoelectric/piezoresistive Materials PZT/LTCC membrane, W. Hermel, P. Otschik, A. Schonecker, Fraunhofer IKTS, Dresden Piezoresistive pressure sensor on LTCC membrane for integrated pressure LTCC. Sensitivity: 1.3 mV/kPa sensor, L Golonka, Wroclaw University Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 21.
    LTCC Passive Integration Status Embedded L Embedded C Cofired R (5 ~ 200 nH) Paste Layer Embedded Surface (up to 25 (50~70 (10 Ω/sq ~ trimmable nf/cm2 with pf/cm2) 100 kΩ/sq) (10 Ω/sq ~ 1 K800) MΩ/sq) ± 5% ± 30% ± 5% ± 30% ± 2% Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 22.
    LTCC Feature Forming Criticalsizes Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 23.
    LTCC Feature Forming techniques SteveDai, SICCAS LTCC Seminar 7_16_2007
  • 24.
    LTCC Feature Forming microchannels Sintering cavity without fugitive material M. R. Gongora-Rubio et al.,Sensors and Actuators (2001) Compensate sagging with supported structure Integrated UV Light Source Controlled firing of fugitive carbon black paste Dia. =150 μm V Thickness = 110 μm Gas: Ne G. Eden, B. Vojak, Univ. of V = 100- 200 V Illinois, Urbana, Illinois, (Courtesy of T. Garino, Sandia) I = 2 mA Steve Dai, SICCAS LTCC Seminar 7_16_2007 Pressure = 200-800 Torr
  • 25.
    LTCC Feature Forming suspendedstructure Antennae Suspended Inductors 1 mm Unfired 1 mm Fired K. A. Peterson et al., CICMT (2005) Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 26.
    LTCC Feature Forming releasedmoving parts Pneumatically driven functional-as- released wheels (3 mm) Setter as fugitive materials K. A. Peterson et al., CICMT (2005) Wheel free to rotate Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 27.
    LTCC Feature Forming UnconventionalForming and Physical Insertion Ion Mobility Spectrometer Heated gas feed tube Rolled IMS drift tube 1 cm Thermistor Contact buried heater 12 mm I.D. K. A. Peterson et al., CICMT (2005) (Courtesy of K. A. Peterson and K. B. Pfeifer, Sandia) Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 28.
    Zero-shrink LTCC Tape transfertape Al2O3 tape Al2O3 tape Al2O3 LTCC Module Sinter LTCC Module LTCC Module removal Al2O3 tape Al2O3 tape Compatible lamination process Limited LTCC layers Require backend Al2O3 removal from surface Post fire surface electrode patterns Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 29.
    Zero-shrink LTCC Tape differentiateshrinkage By W. Wersing et al., Siemens Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 30.
    Zero-shrink LTCC Tape HeralockHL2000 (courtesy of Hereaus) Full ground plane Needs no extra processing Virtually zero x & y shrinkage Very precise dimensional control Fires flat Cavities readily available Allows novel structures Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 31.
    LTCC Applications RF buildingblocks ANT C7 C8 Z1 Multilayer Capacitor Z4 C1 Z2 D1 Z3 C4 TX RX Vertically Coiled C2 C3 D2 C5 Transmission Line BIAS C6 Metal Dielectric Paste Metal Horizontally Coiled Dielectric Tape Transmission Line Dielectric Paste Capacitor Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 32.
    LTCC Applications RF frontendmodules Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 33.
    LTCC Applications Wireless modules IMST radar sensor IMST transceiver module RF moduels, Micro Systems Kyocera PA module – size reduction via passive Engineering GmbH integration Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 34.
    LTCC Applications automotive –slow yet stable growth Bosch electronic turbo charger • working temperature up to 155°C • high vibration stress up to 50g • direct engine mountability • high packaging density (Thick Film -> LTCC) Delphi Delco LTCC ABS controller Delphi Delco LTCC ECU Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 35.
    LTCC Applications Direct MethanolFuel cell Concept for Fuel Cell with integrated pumping and control Gold Flow Field Current Air Holes (anode side) Collector (cathode side) Working Fuel Cell Steve Dai, SICCAS LTCC Seminar 7_16_2007 Assembled Fuel Cell
  • 36.
    LTCC Applications Micro cooling Heat pipes Heat spreader layout of microchannels grey: line + printed resistor, black: cooling channel) Microchannel cooling Heat pipes formed with LTCC micro channels as heat spreader (Kinzy Jones, FIU) (H. Thust, Ilmenau TU) Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 37.
    LTCC Applications Optoelectronic packaging WAVEGUIDE Demodulator IC Input/Output Integrated laser and optical modulator ELECTRICAL Input/Output Embedded optical Photo detector switches Coax cable Polyme r optical waveguide embedded in LTCC LTCC Fibre alignment groove Ball grid array mounting Transimpedance amplifier (flip chip) Photo detector array MEMS package with integrated Embedded passives heaters and thermistors (L. Silicon V-groove (resistors/capacitors) Golonka, Wroclaw U.) Multilayer LTCC Fibre Optic Input/Output substrate CMAC’s System In a Package Vision Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 38.
    Summary LTCC is powerfulplatform integration technology with wide applications Wireless applications is the fastest growth area Material challenges: Base and integrated high K Dielectrics Improved Conductors (Au, Ag, Ag/Pd, Pt, Cu, etc) Precision cofired resistors Magnetic materials Functional materials (Ferroelectric, piezoelectric, magnetic, sensing, …) Process Challenges Combination of tape and thick film processes Thin film process for fine feature forming Interconnect technologies Modeling on sintering of dissimilar materials Integration and Assembly Challenges Application driven Technologically innovative Knowledge-based understanding Steve Dai, SICCAS LTCC Seminar 7_16_2007
  • 39.
    Backup slides Methanol Reformer Cell Phone Receiver 15 mm fuel integrated ENERGY reformers modules 5 mm MICROSYSTEM WIRELESS Direct FUNCTIONS on-chip COMMUNICATIONS Methanol power Fuel Cell ICs amplifiers sensors fuel NEW Micro Hollow Cathode cells MATERIALS & filters 8 mm Discharge (MHCD) PROCESSES light pumps UV light source sources 8.5 mm Power Amplifier temperature chemical reactors PCR E-chip control Pumping/ Mixing V cell sorting Integrated BioChip Technology LIFE DNA Steve Dai, SICCAS LTCC Seminar 7_16_2007 SCIENCES amplification
  • 40.
    Backup slides ~ ~ LNA Bypass Impedance Power and Bias Capacitors Bandpass Filter Matching Line To Bias Amplifier Circuit Trap From Filter Amplifier 1 cm X 1 cm Switch w/ Harmonic 41 components/sq. cm Filter To Mixer Switch Image Reject Filter Transmit Antenna Bias Steve Dai, SICCAS LTCC Seminar 7_16_2007