double heterojunction algaas red low current seven segment displays reliability data description the following cumulative test results have been obtained from testing performed at agilent technologies in accordance with the latest revision of mil- std- 883. hdsp-x100 series HDSP-X101 series agilent technologies tests parts at the absolute maximum rated conditions recommended for the device. the actual performance you obtain from agilent parts depends on the electrical and environmental characteristics of your application but will probably be better than the performance outlined in table 1. table 1. life tests demonstrated performance stress test total units total failure rate test name conditions device hrs. tested failed [1] (% /1k hours) [2] high temperature i f = 15 ma dc 435,000 435 0 0.230 operating life t a = 55 c point typical performance failure rate prediction the failure rate given is at elevated operating conditions. the failure rate will depend on the junction temperature of the device. assum- ing a package thermal resistance of 430 c per watt the calculated temperature rise during testing was approximately 14 c above the ambient temperature. the esti- mated life at different tempera- tures is calculated and listed in the following table. estimations are done using the arrhenius model with the activation energy of 0.43 ev in reference to the mil-hdbk-217 for hybrid products. example of failure rate calculation assume a device operating 8 hours/ day, 5 days/week. the utilization fac- tor, given 168 hours/week is: (8 hours/day) x (5 days/week) / (168 hours/week) = 0.25 notes: 1. for purposes of this data sheet, a failure is any device that (a) has v f greater than 0.5 v over the maximum data sheet specification or (b) has v r smaller than 3.0 v at 100 m a or (c) degrades in light output more than 75%. 2. assuming one failure for calculation. the point failure rate per year (8760 hours) at 55 c ambient temperature is: (0.230% / 1k hours) x 0.25 x (8760 hours/year) = 0.500% per year. similarly, 90% confidence level failure rate per year at 55 c ambient temperature is: (0.529% / 1k hours) x 0.25 x (8760 hours/year) = 1.15% per year.
notes: 3. the point mtbf (representing a typical mtbf) is simply the total device hours divided by the number of failures. since no failures occurred during the testing, the point mtbf and failure rate are calculated assuming one failure. 4. this mtbf and failure rate represent the performance level for which there is a 90% probability of the device doing better than the stated value. this confidence level is based on the statistics of the distribution of failures. the assumed distributi on is exponential. this particular distribution is commonly used in describing useful life failures. this methodology is based on mil-std-690b. note: 5. with the exception of solderability and temperature cycling, all data is generic to seven segment display family. table 2. failure rate prediction point typical performance performance [3] in time [4] in time (90% confidence) ambient junction failure rate failure rate temperature ( c) temperature ( c) mtbf [1] (%/1k hours) mtbf [2] (%/1k hours) 85 99 134,000 0.746 58,000 1.717 75 89 194,000 0.515 84,000 1.185 65 79 287,000 0.348 125,000 0.801 55 69 435,000 0.230 189,000 0.529 45 59 675,000 0.148 293,000 0.341 35 49 1,077,000 0.093 468,000 0.214 25 39 1,769,000 0.057 768,000 0.130 table 3. mechanical and environmental tests units units test name mil-std-883c ref test conditions tested failed physical dimensions 2016 device profile at 20x 197 0 solderability 2003.3 sn 60, pb 40 solder at 260 c for 5 sec. 536 0 temperature 1010.5 -55 to 100 c, 15 min. dwell, 5 min. transfer 536 cycling 20 cycles 0 100 cycles 2 (0.37%) moisture resistance 1004.4 10 days, 90-98% rh, -10 to 65 c, non-operating 392 0 mechanical shock 2002.3 (cond. b) 5 blows each x1, y1, y2 axis 1500 g 0.5 msec. 369 0 vibration fatigue 2005.1 (cond. a) 32 8 hours each x, y, z, 96 hours total, 190 0 60 hz, 20 g min. vibration, variable 2007.1 (cond. a) 3 cycles, 4 min. for each x, y, z axis at 20 g. 190 1 frequency min., 20 to 2000 hz (0.53%) constant 2001.2 1 min. each x1, y1, y2 at 20,000 g 189 0 acceleration (cond. d) lead fatigue 2004.4 (cond. b2) 3 bends 15 degrees min. 45 0 terminal strength 2004.4 (cond. a) 1 lb. for 30 seconds 149 0 solvent resistance 2015.4 solvents tested: 45 0 1/4 isopropyl alcohol and 3/4 mineral spirits salt atmosphere 1009.4 35 c for 24 hrs. 50 0 www.semiconductor.agilent.com data subject to change. copyright ? 1999 agilent technologies, inc. 5954-8454 (11/99)
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