AOS Semiconductor Product Reliability Report AO4850/AO4850L, rev A Plastic Encapsulated Device ALPHA & OMEGA Semiconductor, Inc 495 Mercury Drive Sunnyvale, CA 94085 U.S. Tel: (408) 830-9742 www.aosmd.com This AOS product reliability report summarizes the qualification result for AO4850. Accelerated environmental tests are performed on a specific sample size, and then followed by electrical test at end point. Review of final electrical test result confirms that AO4850 passes AOS quality and reliability requirements. The released product will be categorized by the process family and be monitored on a quarterly basis for continuously improving the product quality. Table of Contents: I. II. III. IV. Product Description Package and Die information Environmental Stress Test Summary and Result Reliability Evaluation I. Product Description: The AO4850 uses advanced trench technology to provide excellent RDS(ON) and low gate charge. The two MOSFETs may be used in H-bridge, Inverters and other applications. II. Die / Package Information: AO4850 AO4850L (Green Compound) Process Standard sub-micron Standard sub-micron Low voltage N channel, Integrated Schottky diode Package Type 8 lead SOIC 8 lead SOIC Lead Frame Cu, D/pad, Ag spot Cu, D/pad, Ag spot Die Attach Ag epoxy Ag epoxy Bond wire S: Cu 2mils; G: Au 1.3mils S: Cu 2mils; G: Au 1.3mils Mold Material Epoxy resin with silica filler Epoxy resin with silica filler Flammability Rating UL-94 V-0 UL-94 V-0 Backside Metallization Ti / Ni / Ag Ti / Ni / Ag Moisture Level Up to Level 1 * Up to Level 1* Note * based on information provided by assembler and mold compound supplier III. Result of Reliability Stress for AO4850 (Standard) & AO4850L (Green) Test Item Test Condition Time Point Solder Reflow Precondition Standard: 1hr PCT+3 cycle reflow@260°°c Green: 168hr 85°°c /85%RH +3 cycle reflow@260°°c Temp = 150°°c, Vgs=100% of Vgsmax - HTGB 168 hrs 500 hrs 1000 hrs Lot Attribution Standard: 83 lots Green: 29 lots 1 lot (Note A*) HTRB Temp = 150°°c, Vds=80% of Vdsmax 168 hrs 500 hrs 1000 hrs 1 lot (Note A*) HAST Pressure Pot 130 +/- 2°°c, 85%RH, 33.3 psi, Vgs = 80% of Vgs max 121°°c, 29.7psi, RH=100% 100 hrs Standard: 81 lots Green: 16 lots Total Sample size Number of Failures 17380 pcs 0 82 pcs 0 77+5 pcs / lot 82 pcs 0 77+5 pcs / lot 5335 pcs 0 50+5 pcs / lot 96 hrs (Note B**) Standard: 83 lots Green: 20 lots 5665 pcs 0 50+5 pcs / lot Temperature Cycle -65°°c to 150°°c, air to air 250 / 500 cycles (Note B**) Standard: 87 lots Green: 29 lots 6380 pcs 50+5 pcs / lot (Note B**) 0 III. Result of Reliability Stress for AO4850 (Standard) & AO4850L (Green) Continues DPA Internal Vision Cross-section X-ray CSAM NA 5 5 5 5 5 5 0 NA 5 5 0 Bond Integrity Room Temp 150°°c bake 150°°c bake 0hr 250hr 500hr 40 40 40 40 wires 40 wires 40 wires 0 Solderability 245°°C 5 sec 15 15 leads 0 Note A: The HTGB and HTRB reliability data presents total of available AO4850 and AO4850L burn-in data up to the published date. Note B: The pressure pot, temperature cycle and HAST reliability data for AO4850 and AO4850L comes from the AOS generic package qualification data. IV. Reliability Evaluation FIT rate (per billion): 128 MTTF = 887 years The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in sample size of the selected product (AO4850). Failure Rate Determination is based on JEDEC Standard JESD 85. FIT means one failure per billion hours. 2 9 9 Failure Rate = Chi x 10 / [2 (N) (H) (Af)] = 1.83 x 10 9 6 MTTF = 10 / FIT =7.77 x 10 hrs = 887 years / [2 x 164 x 168 x 258] = 128 Chi² = Chi Squared Distribution, determined by the number of failures and confidence interval N = Total Number of units from HTRB and HTGB tests H = Duration of HTRB/HTGB testing Af = Acceleration Factor from Test to Use Conditions (Ea = 0.7eV and Tuse = 55°C) Acceleration Factor [Af] = Exp [Ea / k (1/Tj u – 1/Tj s )] Acceleration Factor ratio list: Af 55 deg C 70 deg C 85 deg C 100 deg C 115 deg C 130 deg C 150 deg C 258 87 32 13 5.64 2.59 1 Tj s = Stressed junction temperature in degree (Kelvin), K = C+273.16 Tj u = The use junction temperature in degree (Kelvin), K = C+273.16 k = Boltzmann’s constant, 8.617164 X 10-5eV / K