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Developing Automotive grade MLCCfor Space Applications

民生部品（車載用）をﾍﾞｰｽとした宇宙用積層ｾﾗﾐｯｸﾁｯﾌﾟｺﾝﾃﾞﾝｻの開発

ＭＥＷＳ18 2005.10.28MURATA MFG .CO., LTD.

Kunio Tachi 舘 邦夫

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1）Background2） Present situation of current MLCC for Space3）Trend of dielectric thickness for consumer

application4）Technology to achieve thinner dielectric films5）Collaboration with JAXA MLCC for Space

application by using Automotive Grade MLCC6)Automotive Grade & Space Grade Process Chart7)Capacitance Range for Space Grade Capacitors8)Data of Space Grade Capacitors9)Conclusions

CONTENTS

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1)Current MLCC(Multi-Layer Ceramic Capacitors) for Space application are

designed by using special material (ceramic/electrode/resin ) and design

rule . So, it is very difficult to cost reduction and also becomes difficult to get special material (ceramic/electrode/resin ).

2)And, order intake of MLCC for Space has been decreased. But it needs stability of supply, and Pb free.

3)We(MURATA’)shipment history to the automotive market for the past 2 years has been slightly over 20 billion pcs a year. The field failure rate of capacitors shipped to automotive customers was 1.2ppb.

4)JAXA and MURATA have joined hands in developing MLCC for spaceapplications based on existing automotive grade capacitors.

Background

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NASDA CDS Type

NASDA CKS/1002S Type

JAXA(NASDA) SPEC. Ceramic Capacitor

5

0

20

40

60

80

100

120

140

16095F1

95F2

96F1

96F2

97F1

97F2

98F1

98F2

99F1

99F2

00F1

00F2

01F1

01F2

02F1

02F2

03F1

03F2

04F1

04F2

05F1

<Kpcs/half year>

CKS/1002S(RK-R) CDS(GRH-R/GR-R)

Sales Trend of Capacitor for Space application

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1. Trend of dielectric thickness for consumer applications

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0.1

1

10

100

1980 1985 1990 1995 2000 2005 2010

year

Die

lect

ric

Thi

ckne

ss (

µm )

Trend of dielectric thickness Trend of dielectric thickness (for consumer applications)(for consumer applications)

0603 Size-10uF-6.3V(1μm)

0805 Size-10uF6.3V(1.7μm)

1206 Size-10uF-25V(3μm)

1206 Size-1uF-16V(9μm)

8

0.1

1

10

1980 1985 1990 1995 2000 2005 2010

year

Rat

ed V

olta

ge (V

/µm

)Trend of Rated Voltage and Size Trend of Rated Voltage and Size

0805 Size-0.1uF-25V 0603 Size-0.1uF-16V

0402 Size-0.1uF-10V

1206 Size-0.1uF-50V

0201 Size-0.1uF-10V

1210 Size-0.1uF-50V

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2. Technology to achieve thinner dielectric films

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Low withstanding voltage,shorter life, poor reliability, etc.

Unevenness of inner electrode

Pore

Areas of non-uniform composition

Technologies to achieve thinner dielectric;Mainly 1)Fine ceramic powder

2)High density of green film3)Uniformity of Composition 4)Thin and smooth electrode

Technology to achieve thinner dielectric filmsTechnology to achieve thinner dielectric films

Similar technology would lead to

New technology

Inner electrode

Dielectric layer

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Cross section of 0603 Size X5R 10uF 6.3V

Internal Structure of MLCCInternal Structure of MLCC with latestwith latest TechnologyTechnology

FE-SEM Picture

Number of Dielectric layers:320

Inner electrode :Ni

Fine and uniform grains

Thin and dense dielectric layer

Thin and smooth electrode

500um

Schematic of a Multi Layer Ceramic CapacitorSchematic of a Multi Layer Ceramic Capacitor

Precious Metals Electrode Products Base Metals Electrode Products

Pd or Ag/Pd Ni

1st layer Ag/Pd or Ag Cu (or Ag/Pd)2nd layer Ni Ni3rd layer Sn Sn

Inner electodeTermination

Inner electrode

Termination

1st layer2nd layer3rd layer

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3. Collaboration with JAXA MLCC for Space Application by using Automotive Grade MLCC

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MIXING

DE-AIRING

INCOMING INSP. OFCERAMIC MATERIAL

SHEET CASTING

ELECTRODE PRINTING

STACKING & PRESSING

CUTTING

FIRING

TERMINATION

TERMINATION FIRING

TERMINATION PLANTING

SORTING

GROUP A INSPCTION

OUTGOING INSPECTION

SAM & BURN-IN

SORTING

Addition for SPACE GradeAUTOMOTIVE Grade

GROUP B/C INSPCTION(Periodical)

SPACE Grade

Automotive Grade & Space Grade Process ChartAutomotive Grade & Space Grade Process Chart

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SAM (Scanning Acoustic Microscope)SAM (Scanning Acoustic Microscope)

Water

Transducer

Void

Crack

SAM Picture of Failure

Defect position

ResolutionX-Y direction : 10μmZ direction : 10μm

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Reliability of Automotive Grade capacitorReliability of Automotive Grade capacitor

FR

=8.3*10-9

=8.3Fit

Failure level Symbol : Ｓ (0.001%/1000hrs＝10Ｆｉｔ)

Coefficient Number of sampleCoefficient Number of sample

288*3000*AccelerationAcceleration FactorFactor(128*1)

0.917

Voltage Acceleration = (200/50)^3.5 =128

Temperature Acceleration=2^((125-125)/8)=1

Total Number of hours Total Number of hours =

Sample :1206Size X7R 224K 50VDielectric Thickness :16umTest condition :125C-200VNumber of sample units:72pcs-4lots=288Duration :3,000hours

at125C-50V Confidence Level 60%

Acceleration FactorVoltage: 3.5Temperature:8C

=

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Capacitance Range & Dielectric Thickness Capacitance Range & Dielectric Thickness for Space Grade Capacitorsfor Space Grade Capacitors

TC RATED VOLTAGE(V) CAP.RANGE DIELECTRIC THICKNESS（μm)COG 50 0R5～332 18～137

100 390～182 25～142200 030～391 52～142

X7R 25 221～225 15～4650 221～105 16～66100 102～474 22(SERIES)～130200 152～224 24(SERIES)～28(SERIES)500 102～104 33(SERIES)～37(SERIES)

MIL-PRF-123C MIN DIELECTRIC THICKNESS :0.8mil(20μm) for 50V or 1mil(25.4μm) for ratings above 50V

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Test Sample for Space MLCCTest Sample for Space MLCC

NO SIZE(mm) TC CAP WV1 3216 COG 332K 502 3216 COG 182K 1003 3216 COG 391K 2004 3225 X7R 105K 255 4532 X7R 225K 256 5750 X7R 474K 507 5750 X7R 105K 508 5750 X7R 224K 1009 5750 X7R 474K 10010 5750 X7R 224K 20011 5750 X7R 104K 500

Automotive Grade Space GradeWV ⇒ 1/2WVex. 200V 100V

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Qualification Inspection for Space MLCC to JAXAQualification Inspection for Space MLCC to JAXA

Group Item Test Condition ResultⅠ Thermal shock and voltage conditioning -55⇔125℃ 100cycle & 125℃ 2WV 168HR 0/245

Dielectric withstanding voltage 2.5WV 5sec Insulation resistance(25℃/125℃） WV 120secCap,DF COG(1000pFover)&X7R:1kHz1v,COG(1000pFless):1MHz1V

Ⅱ Visual,Dimension Visual inspection,using calipers 0/15Destructive physical analysis Cutting,Grinding

Ⅲ Terminal strength MIL-STD-202 method 211 0/4Solderability of Termination MIL-STD-202 method 208　230℃ 5sec 0/4Resistance to Soldering Heat MIL-STD-202 method 210 260℃ 10sec 0/4

Ⅳ Voltage temperature limits +25/-55/-125℃　WV 0/12Moisture resistance MIL-STD-202 method 106 20cycle 50VorWV

Ⅴ Humidity Steady State Low voltage MIL-STD-202 method 106A 85℃ 85%RH 240HR 1.3V 0/12Vibration MIL-STD-202 method 213/214 0/10Thermal shock MIL-STD-202 method 107 -55⇔125℃ 100cycle 0/18

Ⅵ Life MIL-STD-202 method 108 125℃ 2WV 4000HR 0/123

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1206 COG332K50(t= 0.7mil< 181206 COG332K50(t= 0.7mil< 18μμm>)m>)

All 12.0 over

10.00

11.00

12.00

13.00

14.00

15.00

Initial 1000 2000 4000[Hr]

IR【

log.IR】

↑ ↑↑ ↑

LIFE TEST(125℃ 2WV 4000HR n=123pcs)

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1210 X7R105K25(t= 0.6mil< 151210 X7R105K25(t= 0.6mil< 15μμm >)m >)

9.00

9.50

10.00

10.50

11.00

Initial 1000 2000 4000[Hr]

IR【log.IR】

LIFE TEST(125℃ 2WV 4000HR n=123pcs)

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8.50

9.00

9.50

10.00

10.50

Initial 1000 2000 4000[Hr]

IR【

log.IR】

1812 X7R225K25(t= 0.6mil< 151812 X7R225K25(t= 0.6mil< 15μμm >)m >)

LIFE TEST(125℃ 2WV 4000HR n=123pcs)

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1812 X7R225K25(t= 0.6mil< 151812 X7R225K25(t= 0.6mil< 15μμm >)m >)

8.50

9.00

9.50

10.00

10.50

50 100 250 500 1000[cycle]

IR【

log.IR】

THERMAL SHOCK(-65℃－+125℃ n=18pcs)

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1812 X7R225K25 (t=0.6mil<151812 X7R225K25 (t=0.6mil<15μμm>)m>)

8.00

8.50

9.00

9.50

10.00

Initial After

IR【

log.IR】

Humidity steady state low voltage(85℃ 85%RH 1.3V 240Hr n=12pcs)

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①GRK-R42-6COG332K50

②GRK-R42-6COG182K100

③GRK-R42-6COG391K200

Tin Whisker(Thermal shock Tin Whisker(Thermal shock --3030⇔⇔100100℃℃1000cycle)1000cycle)

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ConclusionsConclusions

1. JAXA and MURATA have co-developed MLCC for Space applications derived from existing Automotive grade capacitors (SAM and additional burn in tests).

2. Although, the dielectric thickness of MLCC for Space application is below 0.8mil (MIL-PRF-123C spec.), our tests show the reliability to be high and meeting MIL life test condition(125℃ 2WV 4000HR ).

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APPENDIX

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Shipping HistoryShipping History

(1) Murata has been supplying MLCC with nickel internal electrodes (Nickel Electrode Material) to the automotive market for over five years now.

(2) The MLCC industry as a whole supplied about 700 Billion capacitors in 2004.

(3) Murata’s shipment history to the automotive market for the past 2 years has been slightly over 20 billion pieces a year .

(4) The field failure rate of capacitors shipped to automotive customers was 1.2 ppb (past 2 years).

(5) Furthermore, very few of those failures could be related to reliability problems concerning the dielectric film or material. This corroborates our findings in this study that MLCC made with dielectric films thinner than MIL spec of 20μm are reliable enough to be used in Hi-Rel

applications (including automotive).

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1E+2

1E+3

1E+4

1E+5

1E+6

I.R.

(M o

hm)

INITIAL AFTER TEST

ReliabilityReliability of Ni and Pd electrode MLCCof Ni and Pd electrode MLCC

HIGH TEMPERATURE LOAD HUMIDITY LOAD

TEST CONDITION: TEMPERATURE : 40 +/- 2deg. C

HUMIDITY : 90 ~ 95%RH

VOLTAGE : 25 VDC

DURATION : 500 +/- 12 HOURS

TEST CONDITION: TEMPERATURE : 125 +/- 3deg. C

VOLTAGE : 50 VDC

DURATION : 1000 +/- 12 HOURS

Ni electrodePd electrode0805 Size X7R 100nF 25V

n=18pcs

1E+2

1E+3

1E+4

1E+5

1E+6

I.R.

(M o

hm)

INITIAL AFTER TEST

n=18pcs

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Key factors of New TechnologyKey factors of New Technology

Key factors

1)Fine ceramic powder Fineness of raw materials, Mixing, High Crystallinity

2)High density of green film Dispersant, Binder & Casting conditions

3)Uniformity of Composition Composition and Uniform dispersion of dopants

4)Thin and smooth electrode Anti-oxidant fine metal powder, Paste Rheology

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1) Fine ceramic powder1) Fine ceramic powder

Particle Size Distribution of Ceramic powder

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FE-SEM: Surface of green film

2) High density of green film 2) High density of green film

Former Current

Pore2umHigh density

Fine ceramic powder

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2um

FIB-SIM: Cross section of green film

Pore

High density of green Sheet High density of green Sheet

Former Current

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FIBFIB--SIMSIM

Angle of incidence : 5deg.Angle of incidence : 5deg.

FIB:Focused Ion BeamSIM:Scanning Ion Microscope Ga Ion Beam

Detector

Angle of observation picture : 45deg.Angle of observation picture : 45deg.

SIMSIM--PicturePicture

Green SheetGreen Sheet

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Uniformity of green filmWDX Mapping of Mn (dopant material)

3) Uniformity of Composition3) Uniformity of Composition

agglomerationFormer Current

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4) 4) Thin and smooth electrodeThin and smooth electrode

2um

FIB-SIM: Cross section of green chip

Former Current

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Thin and smooth electrodeThin and smooth electrode

Surface roughness of inner electrode

Max peak : 0.9-1.0um

Max peak : <0.5um

Former

Current

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Highly Accelerated Life Test (HALT)Highly Accelerated Life Test (HALT)Sample :1206Size X7R 224K 50VDielectric Thickness :16umTest condition :150C-400VNumber of sample units:18

m-parameter : 2.96

MTTF : 224hrs

Acceleration FactorVoltage: 3.5Temperature:8C

Estimated MTTF at 125C,100%RV : 322years

Weibull distribution

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Voltage Acceleration : Eyring Model

L = C’ x V- a

Hereby is L : Lifetime C’ : ConstantV : Test Voltage a : Acceleration Factor

MLCC Reliability Design (1)MLCC Reliability Design (1)

AL = LN /LA = (VA /VN)n

Hereby is AL : Acceleration FactorLN : Lifetime under Standard ConditionLA : Lifetime under Accelerated ConditionVN: Temperature Standard ConditionVA: Temperature Accelerated Condition n : Voltage Acceleration Factor

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MLCC Reliability Design (2)MLCC Reliability Design (2)

Temperature Acceleration: Ahrenius model

L = C X exp { -Ea/(k XT) }Hereby is L : Lifetime C : Constant

Ea : Activated Energy k : Boltzmann FactorT : Absolute Temperature

AL = LN /LA = 2( t/b )

Hereby is AL : Acceleration FactorLN : Lifetime under Standard ConditionLA : Lifetime under Accelerated Conditiont : Temperature Difference between

Standard & Accelerated Conditionb : Temperature Acceleration Factor

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Introduction of antiIntroduction of anti--deoxidization ceramicsdeoxidization ceramics

Technique for base metal inner electrodeTechnique for base metal inner electrode

Apply base Apply base metal(Nimetal(Ni))

Firing in the deoxidization atmosphere

Following point are requiredFollowing point are required

-- antianti--deoxidization of dielectric.deoxidization of dielectric.-- improve reliability.improve reliability.