AOS Semiconductor Product Reliability Report AO4892, rev A Plastic Encapsulated Device ALPHA & OMEGA Semiconductor, Inc www.aosmd.com This AOS product reliability report summarizes the qualification result for AO4892. 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 AO4892 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 AO4892 uses trench MOSFET technology that is uniquely optimized to provide the most efficient high frequency switching performance. Both conduction and switching power losses are minimized due to an extremely low combination of RDS(ON), Ciss and Coss. This device is ideal for boost converters and synchronous rectifiers for consumer, telecom, industrial power supplies and LED backlighting. Detailed information refers to datasheet. II. Die / Package Information: AO4892 Standard sub-micron 100V Dual N channel Package Type SO8 Lead Frame Cu Alloy Die Attach Ag Epoxy Bonding Cu wire Mold Material Epoxy resin with silica filler MSL (moisture sensitive level) Level 1 based on J-STD-020 Process Note * based on information provided by assembler and mold compound supplier III. Result of Reliability Stress for AO4892 Test Item Test Condition Time Point MSL Precondition 168hr 85°c /85%RH +3 cycle reflow@260°c - HTGB Temp = 150 °c, Vgs=100% of Vgsmax 168hrs 500 hrs 1000 hrs Lot Attribution Total Sample size Number of Failures 29 lots 3575pcs 0 JESD22A113 308pcs 0 JESD22A108 0 JESD22A108 880pcs 0 JESD22A110 1 lot 3 lots Standard 77pcs / lot Temp = 150 °c, Vds=80% of Vdsmax 168hrs 500 hrs 1000 hrs 1 lot 3 lots HAST 130 °c, 85%RH, 33.3 psi, Vgs = 100% of Vgs max 100 hrs 16 lots Pressure Pot 121°°c, 29.7psi, RH=100% 96 hrs (Note A*) 20 lots 55 pcs / lot 1100pcs 0 JESD22A102 Temperature Cycle -65°°c to 150°°c, air to air 250 / 500 cycles (Note A*) 29 lots 55 pcs / lot 1595pcs 0 JESD22A104 (Note A*) 55 pcs / lot HTRB 308pcs 77pcs / lot Note A: The reliability data presents total available generic data up to the published date. IV. Reliability Evaluation FIT rate (per billion): 7 MTTF = 17349 years The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in sample size of the selected product (AO4892). Failure Rate Determination is based on JEDEC Standard JESD 85. FIT means one failure per billion hours. 2 9 Failure Rate = Chi x 10 / [2 (N) (H) (Af)] 9 = 1.83 x 10 / [2x (2x77x500+6x77x1000) x258] = 7 9 8 MTTF = 10 / FIT = 1.52 x 10 hrs = 17349years 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 -5 K = Boltzmann’s constant, 8.617164 x 10 eV / K