surface mount schottky diodes reliability data the following cumulative test results have been obtained from testing performed at hewlett- packard communications com- ponents division in accordance with the latest revision of mil-std-750. data was gathered from the product qualification, reliability monitor, and engineering evaluation. for the purpose of this reliability data sheet, a failure is any part which fails to meet the electrical and/or mechanical specification listed in the hewlett-packard communications components designers catalog. point [1] 90% confidence level [2] junction temp. mttf mttf t j ( c) (hours) fit [3] (hours) fit [3] 150 3.6 x 10 6 278.0 1.6 x 10 6 625.0 140 7.3 x 10 6 137.0 3.2 x 10 6 312.0 130 1.5 x 10 7 67.0 6.5 x 10 6 153.0 120 3.2 x 10 7 31.0 1.4 x 10 7 71.0 100 1.7 x 10 8 6.0 7.4 x 10 7 14.0 75 1.8 x 10 9 0.56 7.8 x 10 8 1.3 50 2.6 x 10 10 0.04 1.1 x 10 10 0.09 b. failure rate prediction the failure rate will depend on the junction temperature of the device. the estimated life at different temperatures is calcu- lated, using the arrhenius plot with activation energy of 1.05 ev, and listed in the following table. 1. life test a. demonstrated performance units total total failure rate test test conditions tested device hrs. failed 1%/1k hrs. high temp. rev. v r = 80% v br , t a = 150 c 127 127,000 0 0 bias (htrb) high temp. p fm = 75 mw, t a = 65 c 129 129,000 0 0 operating v r = 80% v br life (htol) high temp. t a = 150 c 129 129,000 0 0 storage (hts) hsms-8101 hsms-820x hsms-286a/6x
2 400 junction temperature, t j ( c) mean time to failure, mttf (hrs) 350 300 250 200 150 100 50 25 activation energy (ev) 0.7 0.8 0.9 1.0 1.5 2.0 3.0 4.0 0.6 0.5 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 e a = 1.05 ev notes: 1. the point mttf is simply the total device hours divided by the number of failures. 2. the mttf and failure rate represent the performance level for which there is a 90% probability of the device doing better than the stated value. the confidence level is based on the statistics of failure distribution. the assumed distribution is exponential. this particular distribution is commonly used in describing useful life failures. 3. fit is defined as failure in time, or specifically, failures per billion hours. the relationship between mttf and fit is as follows: fit = 10 9 /(mttf). c. example of failure rate calculation at 50 c with a device operating 8 hours a day, 5 days a week, the percent utilization is: % utilization = (8 hrs/day x 5 days/wk) ? 168 hrs/wk = 25% then the point failure rate per year is: (4.0 x 10 -11 /1000 hrs.) x (25%) x (8760 hrs/yr) = 8.76 x 10 -6 % per year likewise, the 90% confidence level failure rate per year is: (9.0 x 10 -11 /1000 hrs.) x (25%) x (8760 hrs/yr) = 1.97 x 10 -5 % per year
3 2. environmental and mechanical tests mil-std-750 units total test reference test conditions tested failed solderability 2026 215 c, 5 seconds 500 0 solder heat 2031 260 c, 10 seconds 426 0 resistance to solvent 1022 4 solvent groups 98 0 autoclave 121 c, 15 psig, 96 hrs. 116 0 moisture resistance 85 c/85% rh, biased, 1000 hrs. 118 0 thermal shock 1056 -65/150 c, 5 min dwell, 163 0 200 cycles temperature cycle 1051 -65/150 c, 10 min dwell, 169 0 200 cycles lead integrity 140 0 3. flammability test: meets needle flame test category d (flaming time <3 sec.) under material classification 94v0. 4. dod-hdbk-1686a esd classification: hsms-8101/820x/286x/286a class i
www.hp.com/go/rf for technical assistance or the location of your nearest hewlett-packard sales office, distributor or representative call: americas/canada: 1-800-235-0312 or 408-654-8675 far east/australasia: call your local hp sales office. japan: (81 3) 3335-8152 europe: call your local hp sales office. data subject to change. copyright ? 1998 hewlett-packard co. obsoletes 5965-9142e printed in u.s.a. 5967-6074e (5/98)
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