evaluation of case size 0603 bme ceramic capacitors · 2016-09-24 · evaluation of case size 0603...

Evaluation of Case Size 0603 BME Ceramic Capacitors

Alexander TeverovskyAS&D, Inc.

[email protected]

NASA Electronic Parts and Packaging (NEPP) Program

1Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov presented by Alexander Teverovsky at the Components for Military and Space Electronics, Conference and Exhibition (CMSE), Los Angeles, CA, March 1-3, 2015.

https://ntrs.nasa.gov/search.jsp?R=20150002857 2020-05-30T16:11:08+00:00Z

List of Acronyms and Symbols


A area of cross-section PME precious metal electrode BME base metal electrode PWB printed wiring board

C capacitance RT room temperature CTE coefficient of thermal expansion STD standard deviation DCL direct current leakage t thickness of the dielectric DWV dielectric withstanding voltage telectr electrification time

E Young’s modulus Tg glass transition temperature Ea activation energy TSD terminal solder dip

HALT highly accelerated life testing Tsold melting temperature of solder HT high temperature VBR breakdown voltage HV high voltage VBR75 third quartile of VBR distribution IR insulation resistance VBRmin minimal VBR in the group LV low voltage VO

++ charged oxygen vacancy MLCC multilayer ceramic capacitor VR rated voltage

N number of layers XRF X-Ray Fluorescence

Abstract

3

High volumetric efficiency of commercial base metal electrode (BME) ceramiccapacitors allows for a substantial reduction of weight and sizes of the parts comparedto currently used military grade precious metal electrode (PME) capacitors. Insertionof BME capacitors in space applications requires a thorough analysis of theirperformance and reliability. In this work, six types of cases size 0603 BME capacitorsfrom three vendors have been evaluated. Three types of multilayer ceramiccapacitors (MLCCs) were designed for automotive industry and three types forgeneral purposes. Leakage currents in the capacitors have been measured in a widerange of voltages and temperatures, and measurements of breakdown voltages (VBR)have been used to assess the proportion and severity of defects in the parts. Theeffect of soldering-related thermal shock stresses was evaluated by analysis ofdistributions of VBR for parts in “as is” condition and after terminal solder dip testing at350°C. Highly Accelerated Life Testing (HALT) at different temperatures was used toassess the activation energy of degradation of leakage currents and predict behaviorof the parts at life test and normal operating conditions. To address issues related torework and manual soldering, capacitors were soldered onto different substrates atdifferent soldering conditions. The results show that contrary to a commonassumption that large-size capacitors are mostly vulnerable to soldering stresses,cracking in small size capacitors does happen unless special measures are takenduring assembly processes.

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov presented by Alexander Teverovsky at the Components for Military and Space Electronics, Conference and Exhibition (CMSE), Los Angeles, CA, March 1-3, 2015.

Outline

4

Introduction. Leakage currents and insulation resistance.

Absorption and leakage currents. Temperature and voltage dependence of leakage currents.

Breakdown voltages. Initial evaluation. Effect of TSD at 350°C.

Degradation of leakage currents during HALT. Activation energy of degradation. Effect of HALT on breakdown voltages.

Effect of soldering. Manual and reflow soldering. Effect of substrate temperature for manual soldering.

Conclusion.Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov presented by Alexander Teverovsky at the Components for Military and Space Electronics, Conference and Exhibition (CMSE), Los Angeles, CA, March 1-3, 2015.

Introduction


Two major issues with MLCC: Insulation Resistance (IR) degradation related to oxygen vacancies. Failures related to soldering induced cracking.

Due to the difference in electro-chemical behavior of Ni and Ag/Pd and formed products, the probability of low-voltage failures for BME is less than for PME capacitors.

BME PME

Intrinsic wear-out failures caused by oxygen vacancies typically do not cause failures during applications.Concentration of VO

++ should be under control to reduce the probability of failures in the presence of defects.

n

i

dVBR

VBRTTFTTF

×= 0

V0++

Degradation in the presence of defects

Results of electro-chemical migration in PME and BME capacitors

The Significance of Breakdown Voltages


In most cases distributions of VBR for BME capacitors are bimodal. The high voltage (HV) mode has tight distributions (STD/Mean

~4%) indicating intrinsic breakdown. The presence of low voltage (LV)

subgroup is due to defects.

BME capacitors with bimodal distributions

breakdown voltage, V

cumu

lative

prob

abilit

y, %

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

The interception point of VBR distribution indicates the proportion of defects, and the spread of VBR towards low voltages indicates the significance of defects.

Lot acceptance criterion: VBRmin/VBR75 > 0.5. Migration of VO

++ in capacitors with defects results in IM failures.

VBR intrinsic

VBR defect

Part Types Used in This Study


X-Ray Fluorescence (XRF) analysis showed that barium titanate ceramics (BaTiO3) doped with different elements (mostly Zr, Y, W) is used in all parts.Same size and nominal auto and general purpose MLCCs

have similar design and materials.

application Mfr. C, µF VR, V t, µm N plates

Margins, µmEnd Cover Side

auto C 0.1 50 8 60 180 110 170

auto M 0.1 50 9 62 125 70 120

auto A 0.1 50 10 46 115 140 110

general C 0.1 50 8 120 150

general M 0.01 25 18 19 170 140 180

general C 0.01 50 15 17 160 220 160

Absorption and Leakage Currents


Direct Current Leakage (DCL) at room temperature (RT) decreases with the electrification time, as ~1/telectr.

Absorption currents at VR prevail during first hours of electrification and depend mostly on the value of capacitance.

Absorption currents are reproducible, increase with voltage, and stabilize at V > ~2VR.

The larger telectr. the better the sensitivity of the DCL/IR testing to the presence of defects.

No significant difference in DCL for generic and auto capacitors.

Relaxation of leakage currents at room temperature

y = 6E-08x-0.801

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E+1 1.E+2 1.E+3 1.E+4

curre

nt, A

time, sec

BME 0603 0.1uF 50V at 22C, 50V

Mfr.C autoMfr.M autoMfr.A autoMfr.C gen

y = 1E-08x-0.569

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E+1 1.E+2 1.E+3 1.E+4

curre

nt, A

time, sec

BME 0603 0.1uF 50V Mfr.M

50V0_50V100V0_100V150V0_150V y = 2E-08x-0.766

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E+1 1.E+2 1.E+3 1.E+4

curre

nt, A

time, sec

BME 0603 0.1uF 50V Mfr.C

25V0_25V50V0_50V100V0_100V150V0_150V

Insulation Resistance


y = 6E-08x-0.695

y = 1E-07x-0.893

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E+1 1.E+2 1.E+3 1.E+4

curre

nt, A

time, sec

0603 BME 0.1uF 50V

RT_Ca RT_Ma RT_A125C_Ca 125C_Ma 125C_AMIL_RT MIL_125 MUR_RTMUR_125

125C

22C

At 125°C intrinsic currents prevail after ~ 100 sec of electrification. IR measurements in LV capacitors during mass production is a

challenge. The test voltage should be increased. IR values for 0603 capacitors are within the range of values typical

for different types of BME MLCCs, but some are out of the MIL limit. MIL requirements for IR do not allow sufficient margin for high

volumetric efficiency BME capacitors. Murata auto limits are more reasonable.

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E+1 1.E+2 1.E+3 1.E+4cu

rrent

, A

time, sec

Mfr.M auto 0603 0.1uF 50V at 85C

25V50V75V100V150V

depolarization

IR_avr = 5E9/C

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

1.E+12

1.E+13

0.001 0.01 0.1 1 10 100

IR, O

hm

capacitance, uF

BME IR_120 sec

all BMEBME 0603murata autoMIL limit

Effect of capacitance on IR in different types of BME capacitors

Relaxation of leakage currents at different temperatures and voltages

Effects of Temperature and Voltage on Leakage Currents


m=2.4m=1.9

m=1.6

m=1.5

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

3 30 300

curre

nt, A

voltage, V

Mfr.C auto 0.1uF 50V

85C_Ca

125C_Ca

150C_Ca

175C_Ca

m=2.6m=2.3

m=2.1

m=1.8

m=1.5

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

10 100

curre

nt, A

voltage, V

Mfr.M 0.01uF 25V

22C85C125C150C175C

m=3.2m=2.3

m=1.8

m=1.5

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

3 30 300

curre

nt, A

voltage, V

Mfr.A auto 0.1uF 50V

85C_Aa125C_Aa150C_Aa175C_Aa

Variations of leakage currents with voltage at different temperatures

1

1.5

2

2.5

3

3.5

75 100 125 150 175 200

m

temperature, deg.C

Variation of exponent m with temperature

Mfr.Ca 0.1uF 50VMfr.Ma 0.1uF 50VMfr.Aa 0.1uF 50VMfr.Mg 0.01uF 25VMfr.Cg 0.1uF 50VMfr.Cg 0.01uF 50V

At high temperatures I-V characteristics in all parts can be described with a power law, I ~Vm.The exponent m decreases with temperature.At 125°C 1.8 < m < 2.2 and at 175°C m ~ 1.5.DCL at HT can be explained based on the

space charge limiting model.

Effects of Temperature and Voltage on Leakage Currents, Cont’d


For BME capacitors activation energy of intrinsic leakage currents decreases with voltage.

Ea for BME is less than for PME capacitors. Voltage and temperature dependencies for

auto and general type capacitors are similar.

0

0.3

0.6

0.9

1.2

1.5

0 50 100 150 200 250

activ

atio

n en

ergy

, eV

voltage, VMfr.Ca 0.1uF 50V Mfr.Ma 0.1uF 50VMfr.Aa 0.1uF 50V M123 1uF 50VMfr.Mg 0.01uF 25V Mfr.Cg 0.1uF 50VMfr.Cg 0.01uF 50V M123 0.1uF 100V

PME

BME

1eV

0.61eV

0.55eV

0.47eV

0.42eV

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

0.002 0.0022 0.0024 0.0026 0.0028 0.003

curre

nt, A

1/T, 1/K

Mfr.A auto, 0603, 0.1uF, 50V25V50V100V150V200V

0.87eV0.73eV

0.6eV 0.55eV

0.52eV

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

0.002 0.0022 0.0024 0.0026 0.0028 0.003

curre

nt, A

1/T, 1/K

Mfr.M auto, 0603, 0.1uF, 50V

25V50V100V150V200V

0.9eV0.69eV

0.57eV

0.51eV

0.47eV

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

0.002 0.0022 0.0024 0.0026 0.0028 0.003

curre

nt, A

1/T, 1/K

Mfr.C auto, 0603, 0.1uF, 50V

25V50V100V150V200V

Variations of leakage currents with temperature at different voltages

Breakdown and Rated Voltages


Tested lots did not have gross defects: VBRmin/VBR75 > 0.5.Thickness of the dielectric is not the only factor determining VBR.No significant difference between automotive and general types of

BME capacitors.VR is 20 to 30 times less than VBR. One of the limiting factors for

VR is voltage dependence of capacitance.

Distributions of VBR for 0603 BME MLCCsCase size 0603 general type BME capacitors


cumu

lative

prob

abilit

y, %

500 2000800 1100 1400 17001.E-1

5.E-11

510

50

100

1.E-1

0.01uF, 50V

0.01uF, 25V

0.1uF, 50VMfr.C, 8um

Mfr.M, 18um

Mfr.C, 15um

BME 0603 0.1uF 50V capacitors


cumu

lative

prob

abilit

y, %

700 1200800 900 1000 11001

5

10

50

99

Mfr.C

Mfr.MMfr.A

autogeneral

0

0.02

0.04

0.06

0.08

0.1

0.12

0 10 20 30 40

capa

cita

nce,

uF

voltage, V

BME 0.1uF 50V capacitors

0603 Mfr.A, 10um0603 Mfr.C, 8um1210 Mfr.C, 23um1210 Mfr.A, 24um

C-V characteristics

HALT, General Type BME Capacitors


1.E-09

1.E-08

1.E-07

1.E-06

1.E+2 1.E+3 1.E+4 1.E+5 1.E+6

curre

nt, A

time, sec

BME MLCCs at 125C 200V

0.01uF 50V Mfr.C

0.01uF 25V Mfr.M

0.1uF 50V Mfr.C0.1uF 50V Mfr.C

0.01uF 25V Mfr.M

0.01uF 50V Mfr.C

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E+2 1.E+3 1.E+4 1.E+5

curre

nt, A

time, sec

BME 0603 at 22C, 200V

1.E-08

1.E-07

1.E-06

1.E-05

1.E+2 1.E+3 1.E+4 1.E+5 1.E+6

curre

nt, A

time, sec

0603 BME MLCCs at 150C 200V

0.01uF 50V Mfr.C

0.01uF 25V Mfr.M

0.1uF 50V Mfr.C

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.0E+05 1.5E+05 2.0E+05 2.5E+05

curre

nt, A

time, sec

0603 BME MLCCs at 175C 200V

0.01uF 50V Mfr.C

0.01uF 25V Mfr.M

0.1uF 50V Mfr.C

At 125°C some degradation was observed in 0.1µF 50V capacitors only.At 150°C degradation in 0.1µF 50V capacitors

was noticeable and some parts failed.All 0.1µF 50V capacitors failed at 175°C, but

0.01 µF capacitors, both 25V and 50V, increased currents ~ 50% only.

Step stress HALT was carried out at T = 22°C, 125°C, 150°C, and 175°C, for 100hr and 200V at each step.

Leakage currents were monitored through the testing.

HALT, Automotive Grade BME Capacitors


1.E-07

1.E-06

1.E-05

1.E-2 1.E-1 1.E+0 1.E+1 1.E+2

curre

nt, A

time, hr

BME auto 0603 0.1uF 50V at 125C 200V

Mfr.A

Mfr.C

Mfr.M

1.E-07

1.E-06

1.E-05

1.E-2 1.E-1 1.E+0 1.E+1 1.E+2

curre

nt, A

time, hr

BME auto 0603 0.1uF 50V at 150C 200V

Mfr.A

Mfr.C

Mfr.M

No current increase for capacitors from Mfr.M that had minimal IR. It is possible that large intrinsic currents mask degradation.Some degradation can be observed at 125°C for Mfr.A and C.Degradation and failures in parts from Mfr.C at 150°C are similar to

generic capacitors from the same manufacturer.Comparison of results for Mfr.C 0.1µF and 0.01µF capacitors

indicates the effect of dielectric thickness on degradation processes.

Variations of leakage currents in 0.1µF 50V size 0603 BME auto capacitors at 200V with time at 125°C and 150°C

Activation Energy of Degradation


y = 1E-13x + 2E-07

y = 3E-12x + 6E-07

y = 2E-11x + 2E-06

1.E-07

1.E-06

1.E-05

1.E+3 1.E+4 1.E+5 1.E+6

curre

nt, A

time, sec

0.1uF 50V BME_C at 200V SN5

125C

150C

175C

Ea=1.6eV

1.E-14

1.E-13

1.E-12

1.E-11

1.E-10

0.0022 0.0023 0.0024 0.0025 0.0026

rate

, A/s

ec

1/T, 1/K

0.1uF 50V BME_C at 200V

SN5

SN6

SN7

Activation energy of degradation is consistent with the migration of positively charged oxygen vacancies model.Degradation at life test and operating conditions is negligibly small.

At Ea ~1.6 eV, the predicted degradation rate at 125°C and 200V is ~ 1.3×10-13 A/sec. Using a conservative estimation for the voltage acceleration constant, n = 3, the rate at 2VR would be ~ 1.5×10-14 A/sec. At this rate it would take ~2×106 years for the current to increase by 1 µA during life testing.

Time dependence of DCL approximated with linear functions.

Temperature dependence of degradation rates for 3 samples.

Effect of HALT on VBR


Parts with higher rate of degradation had a more substantial decrease of VBR.Post-HALT degradation of VBR is consistent with the defect-related

failure model:An IM failure occurs when accumulation of VO

++ at a defect site would be sufficient to increase current density to a level necessary to initiate a local thermal run-away process.

V0++

defect

Effect of HALT on general type BME 0603 MLCC


cumu

lative

prob

abilit

y, %

0 2000400 800 1200 16001

5

10

50

99

Mfr.C0.01uF 50V

Mfr.M0.01uF 25V

initial

after HALT

Comparison of initial and post_HALT distributions of VBR.Effect of HALT on BME auto 0603 MLCC

breakdown voltage, Vcu

mulat

ive pr

obab

ility,

%400 1400600 800 1000 12001

5

10

50

99

Mfr.A

Mfr.M

initial

post HALT

Effect of Soldering Thermal Shock on Breakdown Voltages


BME MLCC 0603 0.1uF 50V Mfr.A


cumu

lative

prob

abilit

y, %

700 1200800 900 1000 11001

5

10

50

99

Mfr.CMfr.A

initial

initialafter TSD at 350C

after TSD at 350C 600

800

1000

1200

1400

1600

1800

600 800 1000 1200 1400 1600 1800

VB

R_T

SD

350,

V

VBR_init, V

BME 0603 capacitors

Mfr.Aa 0.1uF 50VMfr.Ma 0.1uF 50VMfr.Ca 0.1uF 50VMfr.Cg 0.01uF 50VMfr.Mg 0.01uF 25VMfr.Cg 0.1uF 50V

30 capacitors of each type were stressed by the terminal solder dip testing at a solder pot temperature of 350°C (10 cycles).

The effect was evaluated by visual examinations and by comparing initial and post-terminal solder dip (TSD)350 distributions.

No substantial variations in distributions of breakdown voltages after thermal shock testing.TSD_350 does not generate cracks on 0603 BME capacitors.

Effect of Manual Soldering


It is often assumed that large size MLCCs (1210 and above) are more susceptible to cracking.

Insertion of BME MLCCs in hi-rel applications means extensive use of small size capacitors ( below 0805). Are they less vulnerable to cracking?

Experiment: Groups with 14 to 12 samples of 0.1µF, 50V, size 0603 BME MLCCs were soldered manually onto FR4 PWBs using recommended precautions and a soldering iron set to 315°C.

MLCC Open circuit Short circuit Intermittent Total failures

Mfr. C 3/14 2/14 0/14 5/14Mfr. M 1/14 2/14 5/14 8/14Mfr. A 3/12 0/12 2/12 5/12

Manual soldering can cause failures of small size capacitors. Out of 40 samples of 0603 size MLCCs soldered with a soldering

iron at 315°C 70% were electrical failures.

Post-manual-soldering test results

Manual vs. Reflow Soldering


BME 0603 0.01uF 25V capacitors Mfr.M


cumu

lative

prob

abilit

y, %

100 1600400 700 1000 13001

5

10

50

99

initialFR4 PCB soldered by paste reflowFR4 PCB at 150C, manual sold., 0.08" tip at 350CFR4 PCB at 22C, manual sold., 0.03" tip at 350CFR4 PCB at 22C, manual sold., 0.08" tip at 350C

manual soldering, cold FR4 PWB

Effects of manual and reflow soldering were compared by measurements of VBR for case size 0603 BME 0.01uF, 25V capacitors from Mfr.Msoldered onto the same FR4 PWB.

Manual soldering was carried out with different tip sizes (0.03” and 0.08”) and different temperatures of the board (cold, 22°C, and hot, 150°C).

No defects were observed in MLCCs after solder reflow and after manual soldering onto a board preheated to 150°C.Soldering iron tips of larger size increase the probability of failures

from ~20% for 0.03” to ~70% for 0.08”.

0.01uF 25V capacitors failed after manual soldering

crack

Post Soldering Stresses


( ) ( )( )

11

−−

×+

−×−=

cap

PWBPWBcap

rgcapPWBreflow

AAEE

TTαασ

( )

( )1

1−

−

×+

−×=

cap

PWBPWBcap

rsoldcapcoldPWB

AAEE

TTασ

case size

reflow FR4

cold PWB FR4

reflow alumina

cold alumina

0603 32.6 -107 -45.8 -1812225 17.3 -56.7 -37.8 -149

Board

MLCCSolder

Compressive stress

CTEPWB > CTECAP

Tensile strength of X7R ceramics is 70 to 250 MPa. PWB with coefficient of thermal expansion (CTE)PWB > CTEcap

create compressive stresses (σ > 0) in MLCCs after reflow soldering.

Ceramic substrates with CTEPWB < CTEcap create tensile stresses (σ < 0) that are much more dangerous.

The level of stresses caused by solder reflow and manual soldering onto a cold board can be estimated using a one-dimensional model:

Material E, GPa CTE, ppm/oC Tg/Tsold

PWB (FR4) 17 15 150Alumina 360 7.7 230MLCC 100 10

Mechanical characteristics used for stress calculations

Mechanical stresses in MLCCs assembled by reflow and manual soldering (3mm FR4, 1mm alumina)

Reflow soldering onto a PWB creates relatively small compressive stresses in case of FR4 and tensile stresses in case of alumina board.Manual soldering onto cold PWB creates significant tensile stresses.Post manual soldering stresses are greater for small size MLCCs.

Effect of Substrate and Type of MLCC


Manual soldering onto alumina board resulted in less damage compared to FR4 PWB. A contradiction with the model is likely due to a much higher thermal conductivity of alumina (increase T of the board).All case size 0603 0.01 µF 50V capacitors passed DWV test after

reflow soldering. However, contrary to 0.1 µF 50V MLCCs, ~10% of capacitors had defects.

BME 0603 0.01uF 25V capacitors Mfr.M


cumu

lative

prob

abilit

y, %

100 1600400 700 1000 13001

5

10

50

99

initial

ceram PCB at 22C,

FR4 PCB at 22C, manual sold.,

manual sold.,

0.008" tip at 350C

0.08" tip at 350C

0.01uF 25V capacitors were soldered onto alumina and FR4 PWBs manually (350°C)

Mfr.C BME 0603 0.01uF 50V. Effect of soldering.


cumu

lative

prob

abilit

y, %

0 2000400 800 1200 16001

5

10

50

99

in oil

in still air

after reflow soldering loose MLCCs

loose MLCCs

0.01uF 50V capacitors were soldered onto an FR4 PWB by solder reflow

Failures Caused by Manual Soldering


cracks

Typical soldering thermal shock cracks in large MLCCs

Contrary to the annular thermal stress cracks in large size capacitors, cracks in 0603 capacitors occur along the terminations.Termination cracks are not specific for BME

MLCCs only. They were also observed in small-size PME capacitors.

Size 2225

PME 0402

Size 0603

Post soldering cracks in small size MLCCs

Conclusion

Deliverable to NASA Electronic Parts and Packaging (NEPP) Program to be published on nepp.nasa.gov presented by Alexander Teverovsky at the Components for Military and Space Electronics, Conference and Exhibition (CMSE), Los Angeles, CA, March 1-3, 2015. 23

Design, materials, leakage currents and breakdown voltages in automotive and general application capacitors are similar.Leakage currents: at RT absorption currents prevail over intrinsic conduction currents that are several

orders of magnitude less than currents measured within 2 min of electrification; Ea decreases with voltage from ~ 0.9 eV at 0.5VR to ~ 0.5 eV at 4VR. I-V characteristics at HT follow a power low with the exponent decreasing from ~3 at

85°C to ~ 1.5 at 175°C.Degradation of DCL and failures were observed during HALT in

parts having minimal thickness of the dielectric. Activation energy of degradation is large, ~1.6 eV, so no intrinsic wear-out failures are expected at life testing or normal operating conditions.0603 MLCCs are vulnerable to manual soldering and more than

50% of capacitors can fail in case of soldering onto a cold PWB.Board preheating is critical to reduce the probability of failures.Post-soldering fracturing along the terminals is a specific feature

of small-size capacitors.

evaluation of case size 0603 bme ceramic capacitors · 2016-09-24 · evaluation of case size 0603...

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