the significance of breakdown voltages for quality ... · 1.e+06 1.e+07 1.e+08 1.e+09 1.e+10 1.e+11...

20
The Significance of Breakdown Voltages for Quality Assurance of Low-Voltage BME Ceramic Capacitors NASA Electronic Parts and Packaging (NEPP) Program Alexander Teverovsky AS&D Inc. (work performed for GSFC Parts, Packaging, and Assembly Technologies Office, Code 562) [email protected] Base-Metal-Electrode (BME) Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014. https://ntrs.nasa.gov/search.jsp?R=20140005413 2020-08-03T14:32:57+00:00Z

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Page 1: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

The Significance of Breakdown Voltages for Quality Assurance of Low-Voltage BME Ceramic

Capacitors

NASA Electronic Parts and Packaging (NEPP) Program

Alexander TeverovskyAS&D Inc.

(work performed for GSFC Parts, Packaging, and Assembly Technologies Office, Code 562)

[email protected] (BME)

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

https://ntrs.nasa.gov/search.jsp?R=20140005413 2020-08-03T14:32:57+00:00Z

Page 2: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

List of Acronyms and Symbols

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

2

AF acceleration factor Rd resistance associated with defectsBME base metal electrode Ri intrinsic resistance

C capacitance RSH resistance to soldering heatCVR constant voltage ramp S&Q screening and qualificationDCL direct current leakage T temperatureDF dissipation factor Tc Curie temperature

DWV dielectric withstanding voltage TS thermal shockHALT highly accelerated life testing TSD terminal solder dip

HV high voltage TTF time to failureIR insulation resistance VBR breakdown voltageLV low voltage VBR75 third quartile of VBR distribution

MF mechanical fracture VO++ charged oxygen vacancy

MLCC multilayer ceramic capacitor VR rated voltage

PME precious metal electrode X-sect cross-sectionr charge absorption resistance PDA percent defective allowable

Page 3: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Outline

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

3

What limits application of BME MLCCs in hi-relelectronics?

Drawbacks of the existing system of quality assurance for MLCCs.

Factors affecting VBR. Distributions of VBR and their

use for quality assurance. Modeling of life testing. Flash testing for screening. Recommendations. Summary.

Flashover

Page 4: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

What Impedes Application of BME Capacitors in Hi-Rel Systems?

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

4

It is assumed that reliability is limited by high concentration of VO

++. The wear-out problem has been resolved

by using new materials and processes.(Life testing (1000 hr, 2VR, 125 °C) is equivalent to thousands of years at 65 °C and 0.5 VR).

Intrinsic wear-out failures caused by VO

++ do not limit applications. Failures are caused by defects.

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

2 4 6 8 10

time,

yea

rs

voltage acceleration constant, n

Time at 65C, 0.5VR that is equivalent to 1khr life testing

0.7eV 0.9eV1.1eV 1.3eV1.5eV 1.7eV1.9eV

Factors impeding applications: (1) lead-free termination finishing; (2) insufficient data on long-term reliability; (3) the presence of defects introduced either during manufacturing or assembly and handling processes.How effective the existing S&Q system for revealing defects in

MLCCs?

Page 5: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

What is in the Toolbox for S&Q?

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

5

Specified characteristics: C, DF, and IR. DF and IR have only max limit (unknown margin). VR is assigned by manufacturers so that the parts

meet their performance and reliability requirements. DWV test assures that VBR exceeds 2.5VR. Environmental stresses during S&Q testing: HT/HV testing (voltage conditioning and life): Thermal testing (TS, RSH). Humidity testing; No measurements are required during the

environmental testing, and PDA has no limits.Improvements in the S&Q system can be achieved by: increasing the level of stress as necessary; setting PDA limits; monitoring DCL during environmental testing; using new, defect-sensitive, characteristics and tests.

C, DF, IR, DWV

∆T

C, DF, IR, DWV

Page 6: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

The Effectiveness of IR Measurements

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

6

IR is presented by three resistors connected in parallel: absorption (r), intrinsic (Ri), and defects (Rd). Limits for military MLCCs: IR > 1011 Ω or 103 MΩ-µF at +25°C(×0.1 at +125°C).

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

1.E+12

1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12

IR_d

amag

ed, O

hm

IR_initial, Ohm2225 1uF 50V 1206 4.7uF 25V 1210 0.1uF 50V 1812 1uF 100V2220 1uF 50V 0805 3.3uF 6.3V 2220 10uF 50V 1210 0.1uF 50V1825 0.1uF 100V 1206 82nF 50V 1825 1uF 50V 2220 22uF 25V2223 22nF 50V 1206 0.47uF 16V 2220 100uF 6.3V 1825 0.47uF 50V

Room temperature

High absorption currents at RT, and large intrinsic leakage currents at HT mask the presence of defects.

The probability of revealing a defect decreases for capacitors with larger C and smaller VR.

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

1.E+05 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11

IR_d

amag

ed, O

hm

IR_virgin, Ohm

M1206 22uF 6.3VC1206 4.7uF 25VM1206 10uF 16VA1206 0.47uF 25VV1825 0.47uF 50VA1825 0.47uF 50VC1825 0.47uF 50VA 1825 1uF 50VP 1825 1uF 50V

85C, 125C, 165C

[ ] [ ] 1111 ),(),( −−−− ++= di RVTRCtrIR

Page 7: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

The Effectiveness of DWV Testing

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

7

27 lots of low-voltage MLCCs were tested in virgin condition, after mechanical fracture (MF) at the corner, after cross-sectioning (X-sect), and after thermal shock (TS).

The probability of failure during DWV testing for capacitors even with rough mechanical fractures was low.

The existing screening techniques (C, DF, IR, and DWV) are capable to determine only gross defects in the parts.

Gr.2 1812 Mfr.A 1uF 50V

breakdown voltage, V

cumu

lative

prob

abilit

y, %

60 2000100 10001

5

10

50

90

99

virgin

TS

X-sect

MF

DWV

Gr.6 2225 Mfr.C 1uF 50V

breakdown voltage, Vcu

mulat

ive pr

obab

ility,

%60 2000100 1000

1

5

10

50

90

99

virgin

TS

X-sect

MF

DWV

Page 8: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

The Effectiveness of VBR Measurements

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

8

Local defects do not change C, DF and IR, but affect VBR.

If a capacitor passed DWV testing, should we care about VBR?(Designers’ and QA approaches)

defect

High values of VBR (similar to IR) provide assurance that the parts have no gross defects that might cause failures.Contrary to IR, VBR can be measured accurately.The consistency of the distributions indicates stability of the

manufacturing process and quality of the product.

VBR intrinsic VBR intrinsic

VBR defectVBRi < VBRd

Page 9: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Constant Voltage Ramp Technique

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

9

Factors affecting VBR: Ramp rate. Maximum current. Medium.

No significant variations in VBR at ramp rates from 25 V/s to 100 V/s.

Current limit in the range from 1 mA to 10 mA will not result in substantial variations of VBR.

CVR failures are due to thermal breakdown.

Testing in oil increases VBR by 10% to 50%.

400

420

440

460

480

500

520

540

0 50 100 150 200 250

VB

R, V

ramp rate, V/sec

MLCC 0805 1uF 10V

A B C

0.E+00

2.E-03

4.E-03

6.E-03

8.E-03

1.E-02

300 400 500 600

curr

ent,

A

voltage, V

MLCC 0805 1uF 10V CVR at 100 V/sec

Gr.BGr.AGr.C

MLCCs size 1825 0.47uF 50V

breakdown voltage, V

cumu

lative

prob

abilit

y, %

600 2100900 1200 1500 18001

5

10

50

99

BME_A, oil

BME_C, oil

BME A

BME_A, air

BME_C, air

PME_C, oil/airPME_V, oil/air

Page 10: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Distributions of VBR

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

10

In most cases distributions of VBR for BME capacitors are bimodal. The HV mode has tight distributions (STD/Mean ~4%) indicating

intrinsic breakdown. The presence of LV subgroup is due to defects.

The point of interception indicates proportion of defects in the lot.The spread of VBR towards low voltages indicates the

significance of these defects.

0.1uF 25V and 50V BME MLCCs

breakdown voltage, V

cumu

lative

prob

abilit

y, %

0 2500500 1000 1500 20001

5

10

50

99

0805 15um 25V M

0805 13um 25V A

0603 8um 50V C

1210 26um 50V C

BME capacitors with bimodal distributions

breakdown voltage, Vcu

mulat

ive pr

obab

ility,

%200 2200600 1000 1400 18001

5

10

50

99

1812 1uF 50V

0805 0.1uF 25V

0805 0.12uF 50V

1210 0.1uF 50V12 um, floating electrode

15 um

13 um

14 um

Page 11: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Distributions of VBR, Cont’d

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

11

Comparison of distributions for the same type of BME capacitors.

Analysis of distributions allows for assessment of the quality of capacitors and revealing improvements.Automotive industry and general purpose parts might be from

the same population and have similar defects.

MLCC size 0805 1uF 10V Mfr.A

breakdown voltage, V

cumu

lative

prob

abilit

y, %

100 600200 300 400 5001

5

10

50

99

2001, 6um

2013, 5um

BME MLCCs 1210 10uF 25V

breakdown voltage, V

cumu

lative

prob

abilit

y, %

250 500300 350 400 4500.1

0.51.0

5.010.0

50.0

99.9

0.1

Mfr.M, 5um

Mfr.T general, 4.5umMfr.T auto, 4.5um

Page 12: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Analysis of VBR Distributions for QA

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

12

Out of 27 types of BME capacitors 67% had bimodal distributions.

The proportion of capacitors with defects was from 2.6% to 80%.

The significance of the defects (the ratio of VBRmin and VBR75) varied from 0.3 to 0.95.

Assuming that acceptable defects would reduce breakdown voltage less than 2 times, 5 out of 27 lots should be rejected.

Analysis of distributions of VBR allows for the assessment of the quality of the lot.The lot is acceptable for space applications if VBR/VBR75 > 0.5.

BME_A 1825 1uF 50V

breakdown voltage, V

cumu

lative

prob

abilit

y, %

800 18001000 1200 1400 16001

5

10

50

99

VBR75

VBRmin

Page 13: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Rated and Breakdown Voltages

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

13

VBR exceeds VR more than 15 times.

Breakdown voltages on average increased with the rated voltage.

The spread of the data was large: at VR = 50 V, VBR varied from 17VR to 45VR.

Breakdown voltage is not a limiting factor in assigning VR to low-voltage capacitors.

In class II dielectrics VR is limited by the non-linearity of polarization that results in decrease of capacitance with voltage.

0

500

1000

1500

2000

2500

0 20 40 60

brea

kdow

n vo

ltage

, V

rated voltage, V

Low-voltage BME MLCCs

Page 14: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Effect of Soldering Stresses

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

14

3 cycles of TSD testing at Tsolder = 350 °C. Case size 1825, 0.47 µF, 50 V capacitors

were tested after manual soldering with a soldering iron set to 350 °C.

Stresses related to manual soldering can degrade VBR.VBR should be used to assess the

possibility of manual soldering.

BME 0805 0.12uF 50V Mfr.A

breakdown voltage, V

cumu

lative

prob

abilit

y, %

500 1500700 900 1100 13001

5

10

50

99

initialafter TSD_350

BME 0805 0.47uF 16V Mfr.Pa

breakdown voltage, V

cumu

lative

prob

abilit

y, %

500 800560 620 680 7401

5

10

50

99

initial

after TSD_350BME 1825 0.47uF 50V, Mfr.A

breakdown voltage, V

cumu

lative

prob

abilit

y, %

0 2500500 1000 1500 20001

5

10

50

99

manual soldering

TSD_350Cvirgin

intrinsicbreakdown

Page 15: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Simulation of Life Testing (2VR, 125°C)

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

15

Assumptions: intrinsic degradation for a defect-free part results in failures at TTF0 and the voltage AF follows Prokopowicz-Vaskas equation with n ~ 3 for PME and n from 4 to 9 for BME capacitors.

Similar defects are more likely to cause life test failures in BME compared to PME capacitors.

The greater the voltage acceleration constant n and the lowerVBR/VBR75 , the more probable infant mortality failures are.

n

i

dVBR

VBRTTFTTF

×= 0

VBR intrinsic VBR

defectV0+

+

TTFs were calculated based on VBR assuming for PME TTF0=50 khr, and for BME TTF0=10 khr.

BME

0805 0.1uF 25V, life test simulation

time, hrcu

mulat

ive pr

obab

ility,

%1.E-1 1.E+51 10 100 1000 100001

5

10

50

90

99

BME, n = 9

BME, n = 3PME, n = 3

β=0.3

β=0.9

PMEBME

β=3 to 9

Page 16: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

2.E-09

2.E-08

2.E-07

1 10 100

curre

nt, A

time, hr

MLCCs 1210, 0.1uF, 50V

PME (7 damaged and 3 virgin)

BME (3 virgin)

BME (7 damaged)

BME_A 1825 1uF 50V

breakdown voltage, Vcu

mulat

ive p

roba

bility

, %0 2000400 800 1200 1600

1

5

10

50

99

initialafter HALT(160hr, 175C, 100V)

Effect of Defects in MLCCs on Reliability

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

16

BME and PME MLCCs with introduced defects were stressed by HALT.

Defects resulting in DCL degradation of BME capacitors might not affect PME capacitors.VBR for BME capacitors degrades after HALT.The effect is more significant for the LV subgroup of MLCCs.

Page 17: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Flash Testing

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

17

DWV testing can reveal only gross defects in low-voltage BME capacitors.

Testing at higher voltages would be more effective.

Time of exposure to HV should be reduced.

The third quartile is close to the mean value of VBR for the HV subgroup of capacitors.

Flash testing should be carried out at the same conditions as VBR measurements, except for it does not require oil as the medium and maximum applied voltage is limited to 0.5×VBR75_air.

BME 0805 0.1uF 25V

breakdown voltage, Vcu

mulat

ive pr

obab

ility,

%

0 1500300 600 900 12001

5

10

50

99

DWV Flash

75%

Flash

VBR_75%

Page 18: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Can Exposure to HV Cause Damage?

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

18

Different types of BME MLCCs were characterized before and after stressing with 1 to 5 sec pulses at V ~ 0.7VBR

No effect on leakage current and VBR. Remnant polarization can decrease C; however, this effect

decreases with time of storage and disappears after annealing at T > Tc (~ 120 °C).

No risks associated with HV exposure.

20

30

40

50

60

70

80

0 20 40 60 80 100

leak

age

curr

ent,

uA

cycle

BME Mfr.T 0603 0.47uF 10V cycling at 300V (VBR = 422V)

SN10 SN11

SN12 SN13

SN14 300V

300

600

900

1200

300 600 900 1200

VB

R_p

ost_

cycl

ing,

V

VBR_init, V

Effect of high-voltage cycles

Mfr.T 0603 0.47uF 10V after 100c 300VMfr.M 0.01uF 25V 0603 after 100c 500VMfr.M 0.1uF 25V 0805 after 100c 400V

0.5

0.6

0.7

0.8

0.9

1

1.1

init 1 min af ter HV

1.5hr af ter HV

70hr af ter HV

af ter 1hr at 175C

C/C

_bak

e

0805 0.1uF 25V Mfr.M 0603 0.01uF 25V Mfr.M0603 0.1uF 50V Mfr.C 0805 0.1uF 25V Mfr.A0805 1uF 10V Mfr.M

Page 19: The Significance of Breakdown Voltages for Quality ... · 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12 1.E+06 1.E+07 1.E+08 1.E+09 1.E+10 1.E+11 1.E+12; IR_damaged, Ohm; IR_initial,

Recommendations

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

19

A lot should be characterized by a distribution of VBR based on 50 samples tested in oil (and in air for gr. C qualification testing) at maximum current of 10 mA and voltage ramp of 25 V/sec for C ≥ 1 µF and 100 V/sec for C < 1 µF. The values of VBR75_oil, VBR75_air, and VBRmin allow for the assessment of the consistency in quality, as a baseline to determine conditions for the flash testing, and to evaluate results of the RSH test.

Lots with VBRmin< 0.5×VBR75_oil have a higher risk of failures and should not be accepted for space applications.

Flash testing should be used as a screening procedure at the same conditions as VBR measurements, except for it does not require oil as the medium and maximum applied voltage is limited to 0.5×VBR75_air.

VBR measurements should be used as a lot acceptance procedure after RSH testing using 30 samples minimum. The acceptance criterion: VBRmin > 0.5×VBR75_oil or VBRmin > 0.5×VBR75_air for the parts soldered onto a test board.

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Summary

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov originally presented by Alexander Teverovsky at the Capacitors and Resistors Technology Symposium (CARTS) conference, Santa Clara, California, April 1-3, 2014.

20

Reliability of BME MLCCs is limited by defects. The existing S&Q system can reveal only gross

defects. Analysis of VBR distributions allows for estimation

of the proportion and severity of the defects. Recommendations for using VBR measurements

for S&Q are suggested.