AOS Semiconductor Product Reliability Report AO4854, rev B Plastic Encapsulated Device ALPHA & OMEGA Semiconductor, Inc www.aosmd.com This AOS product reliability report summarizes the qualification result for AO4854. 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 AO4854 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 AO4854 uses advanced trench technology to provide excellent RDS(ON) and low gate charge. The two MOSFETs make a compact and efficient switch and synchronous rectifier combination for use in DC-DC converters. -RoHS Compliant -Halogen-Free Detailed information refers to datasheet. II. Die / Package Information: AO4854 Standard sub-micron Low voltage 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 AO4854 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 1 lot 308pcs 0 JESD22A108 0 JESD22A108 880pcs 0 JESD22A110 3 lots (Note A*) Standard 77pcs / lot Temp = 150 °c, Vds=80% of Vdsmax 168hrs 500 hrs 1000 hrs 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 1 lot 3 lots (Note A*) 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 = 15704 years The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in sample size of the selected product (AO4854). 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 (2x77x168+6x77x1000) x258] = 7 9 8 MTTF = 10 / FIT = 1.38 x 10 hrs = 15704 years 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