Accelerated Aluminum Electrlytic Capacitr Life Testing: Hw t Pick the Mst Reliable E-Cap in a Few Weeks Stephani Gulbrandsen September 18, 2014 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Overview E-caps Intrductin External Cnstructin Internal Cnstructin E-cap Failure Catastrphic Degradatin Wear-ut Criteria Testing Hw t Chse an E-cap Traditinal Trends in Traditinal Data Accelerated Calculatins Accelerated Critical Weight Lss Accelerated Calculatins Accelerated Wear-Out Failure Mde Benefits f Accelerated Apprach Accelerated Life Test Suppliers A & B Overview Suppliers A & B Rate f Weight Lss Suppliers A & B Critical Weight Lss Suppliers A & B Cmparisn Suppliers C & D Overview Suppliers C & D Rate f Weight Lss Suppliers C & D Critical Weight Lss Suppliers C & D Cmparisn Cnclusins 1 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Overview E-caps Intrductin External Cnstructin Internal Cnstructin E-cap Failure Catastrphic Degradatin Wear-ut Criteria Testing Hw t Chse an E-cap Traditinal Trends in Traditinal Data Accelerated Calculatins Accelerated Critical Weight Lss Accelerated Calculatins Accelerated Wear-Out Failure Mde Benefits f Accelerated Apprach Accelerated Life Test Suppliers A & B Overview Suppliers A & B Rate f Weight Lss Suppliers A & B Critical Weight Lss Suppliers A & B Cmparisn Suppliers C & D Overview Suppliers C & D Rate f Weight Lss Suppliers C & D Critical Weight Lss Suppliers C & D Cmparisn Cnclusins 2 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
E-cap 3 E-cap 2 E-cap 1 E-caps Intrductin Datasheet lifetime Trad test (life)time Accel test time Industrial custmer cmmunicatin interface PCBA frm Mnic Inc. Digital media player PCBA frm Shenzhen Sinetech Electrnic C Ltd. Datasheet lifetime Trad test (life)time Accel test time Datasheet lifetime Trad test (life)time Accel test time Time Cmparisn f datasheet lifetime, traditinal test (life)time, and accelerated test time. Autmtive asset tracking PCBA frm Theta Engineering Inc. 3 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
E-caps External Cnstructin Ande (+) Al can Cathde (-) Rubber bung Vent E-cap external cnstructin. Radial lead Axial lead Screw terminal Snap in Fur types f E-cap leads. 4 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Ande fil Al 2 O 3 dielectric Electrlyte Paper separatr Cathde fil E-caps Internal Cnstructin e - e - Internal sandwich structure f an E-cap. CT scan shwing the crimped seal between the can and the bung. Tp-dwn view f the rlled sandwich structure f an E-cap. 5 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Overview Aluminum Electrlytic Capacitrs Intrductin External Cnstructin Internal Cnstructin E-cap Failure Catastrphic Degradatin Wear-ut Criteria Testing Hw t Chse an E-cap Traditinal Trends in Traditinal Data Accelerated Calculatins Accelerated Critical Weight Lss Accelerated Calculatins Accelerated Wear-Out Failure Mde Benefits f Accelerated Apprach Accelerated Life Test Suppliers A & B Overview Suppliers A & B Rate f Weight Lss Suppliers A & B Critical Weight Lss Suppliers A & B Cmparisn Suppliers C & D Overview Suppliers C & D Rate f Weight Lss Suppliers C & D Critical Weight Lss Suppliers C & D Cmparisn Cnclusins 6 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
E-cap Failure Catastrphic Catastrphic failure Overstress Vltage Current Temperature Reverse plarity Bad electrlyte Catastrphic failure resulting in significant leakage f electrlyte frm E-cap vent. Catastrphic failure resulting in blwn capacitrs. 7 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
E-cap Failure Degradatin Degradatin failure Wear-ut Bad electrlyte Degradatin failure resulting in tented vent and ppped bung. Functining E-cap indicated by flat vent and in place bung. 8 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
E-cap Failure Wear-Out Apply ripple and bias e - e - e - PCB Heating f the capacitr frm applied ripple current causes evapratin f the electrlyte. e - PCB Internal pressure increase frm electrlyte evapratin facilitates electrlyte egress between the rubber bung and Al case. 9 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Ande fil Al 2 O 3 dielectric Electrlyte Paper separatr Cathde fil Ande fil Al 2 O 3 dielectric Electrlyte Paper separatr Cathde fil % Increase ESR E-cap Failure Criteria Capacitance Change Dissipatin Factr* Leakage Current Within +/- 20% f initial value Nt mre than 200% f the specified value Initial specific value r less *Prprtinal t Equivalent Series Resistance (ESR). Electrlyte evapratin 200% Time 10 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Overview Aluminum Electrlytic Capacitrs Intrductin External Cnstructin Internal Cnstructin E-cap Failure Catastrphic Degradatin Wear-ut Criteria Testing Hw t Chse an E-cap Traditinal Trends in Traditinal Data Accelerated Calculatins Accelerated Critical Weight Lss Accelerated Calculatins Accelerated Wear-Out Failure Mde Benefits f Accelerated Apprach Accelerated Life Test Suppliers A & B Overview Suppliers A & B Rate f Weight Lss Suppliers A & B Critical Weight Lss Suppliers A & B Cmparisn Suppliers C & D Overview Suppliers C & D Rate f Weight Lss Suppliers C & D Critical Weight Lss Suppliers C & D Cmparisn Cnclusins 11 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Testing Hw t Chse an E-cap Supplier Vltage (V) Capacitance (uf) Max Operating Temperature Size Ripple (marms 85 C 120 Hz) V 10 470 85 C 8 x 9 360 2000 W 10 470 85 C 6.3 x 11 350 2000 X 10 470 85 C 6.3 x 11 320 2000 Y 10 470 85 C 6.3 x 11 350 2000 Z 10 470 85 C 6.3 x 11 350 2000 Endurance (Lad) Life* *See datasheet fr infrmatin n test cnditins. Typically at rated temperature and vltage, but may r may nt apply ripple current. Datasheets fr example capacitrs stated nly max temperature with rated vltage were applied. 12 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Testing Traditinal Apply rated ripple and bias at rated temperature. e - e - Oven and ripple current heating causes electrlyte evapratin. e - e - Turn ff electricity and cl t rm temperature. PCB PCB PCB N. Cntinue testing. Weigh. Yes. Testing is cmplete. Did ESR have a >200% increase frm the initial value? Measure ESR Electrical characterizatin. Weight: 1.432 g 13 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Weight Lss % Increase ESR Testing Trends in Traditinal Data 800% 600% 400% 200% 1000 2000 3000 4000 Time (hurs) Linear thrughut entire test lifetime f an E-cap ppulatin. Impact n Rate Variable f Weight Lss Ambient temperature Applied ripple current Heat dissipatin Space between bung and can 1000 2000 3000 Time (hurs) 4000 Expnential behavir that is relatively cnstant until apprach time t failure. Variable Electrlyte stability Initial ESR measurement Impact n Time t 200% Increase in ESR 14 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Weight Lss % Increase ESR Testing Accelerated Calculatins 800% 600% 400% Critical weight lss 200% 1000 2000 3000 4000 Accelerated test lifetime Time (hurs) Weight Lss Critical weight lss 1. Critical weight lss at 200% increase in ESR is calculated using the ESR-Weight Lss curve 2. Rate f weight lss is extraplated t the critical weight lss and the crrespnding time is recrded as the accelerated test lifetime 15 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Testing Accelerated Critical Weight Lss Puncture a hle in the capacitr. Oven heating causes electrlyte evapratin. Turn ff heat and cl t rm temperature. N. Cntinue testing. Weigh. Yes. Testing is cmplete. Did ESR have a >200% increase frm the initial value? Measure ESR Electrical characterizatin. Weight: 1.432 g 16 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Testing Accelerated Wear-Out Failure Mde Critical weight lss test Dried ut, ff white paper indicative f electrlyte evapratin. Grey paper indicative f electrlyte saturatin. As-received 17 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Testing Benefits f Accelerated Apprach 500 1,000 hurs f testing fr rate f weight lss and critical weight lss data Time is dependent n capacitr size Traditinal testing lasts 1,000 t >10,000 hurs with significant variability (0.5x 3x) when cmpared t datasheet lifetime Allws fr determinatin f relative reliability f capacitrs with cmparable electrical and physical characteristics under same test cnditins Useful fr determining which supplier is mre reliable fr the same applicatin Traditinal testing calculates actual time t failure fr a given ppulatin f capacitrs 18 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Overview Aluminum Electrlytic Capacitrs Intrductin External Cnstructin Internal Cnstructin E-cap Failure Catastrphic Degradatin Wear-ut Criteria Testing Hw t Chse an E-cap Traditinal Trends in Traditinal Data Accelerated Calculatins Accelerated Critical Weight Lss Accelerated Calculatins Accelerated Wear-Out Failure Mde Benefits f Accelerated Apprach Accelerated Life Test Suppliers A & B Overview Suppliers A & B Rate f Weight Lss Suppliers A & B Critical Weight Lss Suppliers A & B Cmparisn Suppliers C & D Overview Suppliers C & D Rate f Weight Lss Suppliers C & D Critical Weight Lss Suppliers C & D Cmparisn Cnclusins 19 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Accelerated Life Test Suppliers A & B Overview The accelerated test apprach was used t cmpare the behavir f the fllwing tw E-caps Supplier Capacitance (mf) Size (mm) Rated Lifetime (hrs) Vltage (V) A 68 18 x 31.5 10,000 450 1575 B 68 18 x 40 >15,000 450 1517 Rated Ripple Current (ma RMS) * Ripple applied at 120 Hz. 20 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Accelerated Life Test Suppliers A & B Rate f Weight Lss 450 V, 68 mf Supplier A Rate f Weight Lss ½ Supplier B Rate f Weight Lss Supplier A capacitrs have a better seal between the can and bung 21 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Accelerated Life Test Suppliers A & B Critical Weight Lss 450 V, 68 mf Supplier A Critical Weight Lss Supplier B Critical Weight Lss Chemical stability f Supplier A and Supplier B electrlyte is cmparable 22 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Accelerated Life Test Suppliers A & B Cmparisn Accelerated life test results indicate that the Supplier A E-cap is mre reliable than Supplier B This is ppsite what the datasheet lifetimes suggest Supplier A Supplier B 23 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Accelerated Life Test Suppliers C & D Overview The accelerated test apprach was used t cmpare the behavir f the fllwing E-caps Supplier Capacitance (mf) Size (mm) Rated Lifetime (hrs) Vltage (V) C 2.2 10 x 20 10,175 450 43 D 2.2 10 x 20 5,000 450 29 Rated Ripple Current (ma RMS) * Ripple applied at 120 Hz. 24 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Accelerated Life Test Suppliers C & D Rate f Weight Lss 450 V, 2.2 mf Supplier C Rate f Weight Lss 2 Supplier D Rate f Weight Lss Supplier C capacitrs have a wrse seal between the Al can and bung 25 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Accelerated Life Test Suppliers C & D Critical Weight Lss 450 V, 2.2 mf Supplier C Critical Weight Lss 2.5 Supplier D Critical Weight Lss Supplier C capacitrs have a mre chemically stable electrlyte 26 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Accelerated Life Test Suppliers C & D Cmparisn Accelerated life test results indicate that the Supplier C E-cap is mre reliable than Supplier D This supprts what the datasheet lifetimes suggest Supplier C Supplier D 27 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Overview Aluminum Electrlytic Capacitrs Intrductin External Cnstructin Internal Cnstructin E-cap Failure Catastrphic Degradatin Wear-ut Criteria Testing Hw t Chse an E-cap Traditinal Trends in Traditinal Data Accelerated Calculatins Accelerated Critical Weight Lss Accelerated Calculatins Accelerated Wear-Out Failure Mde Benefits f Accelerated Apprach Accelerated Life Test Suppliers A & B Overview Suppliers A & B Rate f Weight Lss Suppliers A & B Critical Weight Lss Suppliers A & B Cmparisn Suppliers C & D Overview Suppliers C & D Rate f Weight Lss Suppliers C & D Critical Weight Lss Suppliers C & D Cmparisn Cnclusins 28 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Cnclusins The Al ECap accelerated life test apprach is an effective way t cmpare the reliability f the same capacitrs frm different manufacturers under applied test cnditins Test results indicated that datasheet lifetime values can be inaccurate when cmpared t the reliability test results 29 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm
Questins??? Stephani Gulbrandsen is a Member f the Technical Staff at DfR Slutins. Prir t this she cmpleted a master s degree at Gergia Tech in Materials Science and Engineering. Stephani has used her research experience t develp accelerated electrlytic capacitr testing. In her free time she enjys cking and spending time with her family. 30 9000 Virginia Manr Rd Ste 290, Beltsville MD 20705 301-474-0607 www.dfrslutins.cm