AOS Semiconductor Product Reliability Report AO4818B/AO4818BL, rev A Plastic Encapsulated Device ALPHA & OMEGA Semiconductor, Inc 495 Mercury Drive Sunnyvale, CA 94085 U.S. Tel: (408) 830-9742 www.aosmd.com 1Aug, 2007 1 This AOS product reliability report summarizes the qualification result for AO4818B. 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 AO4818B 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. V. I. Product Description Package and Die information Environmental Stress Test Summary and Result Reliability Evaluation Quality Assurance Information Product Description: The AO4818B uses advanced trench technology to provide excellent RDS(ON) and low gate charge. This device is suitable for use as a load switch or in PWM applications. Standard Product AO4818B is Pb-free (meets ROHS & Sony 259 specifications). Absolute Maximum Ratings TA=25°C unless otherwise noted Parameter Symbol Maximum Units Drain-Source Voltage VDS 30 V Gate-Source Voltage VGS ±20 V Continuous Drain Current TA=25°C TA=70°C Pulsed Drain Current TA=25°C Power Dissipation TA=70°C Avalanche Current Repetitive avalanche energy 0.3mH Junction and Storage Temperature Range Thermal Characteristics Parameter Maximum Junction-toAmbient Maximum Junction-toAmbient Maximum Junction-to-Lead 8.5 ID 6.6 IDM 30 2 PD W 1.28 IAR 16 EAR 38 TJ, TSTG -55 to 150 Symbol T ≤ 10s SteadyState SteadyState A RθJA RθJL °C Typ Max Units 48 62.5 °C/W 74 110 °C/W 35 40 °C/W 2 II. Die / Package Information: Process Package Type Lead Frame Die Attach Bond wire Mold Material Filler % (Spherical/Flake) Flammability Rating Backside Metallization Moisture Level AO4818B AO4818BL (Green Compound) Standard sub-micron Low voltage N channel process 8 leads SOIC Copper with Solder spot Ag epoxy S: Cu 2mils; G: Au 1.3mil Epoxy resin with silica filler 90/10 UL-94 V-0 Ti / Ni / Ag Up to Level 1 * Standard sub-micron low voltage N channel process 8 leads SOIC Copper with Solder spot Ag epoxy S: Cu 2mils; G: Au 1.3mil Epoxy resin with silica filler 100/0 UL-94 V-0 Ti / Ni / Ag Up to Level 1* Note * based on info provided by assembler and mold compound supplier III. Result of Reliability Stress for AO4818B (Standard) & AO4818BL (Green) Test Item Test Condition Time Point Lot Attribution Total Sample size 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 0hr Standard: 83 lots Green: 29 lots 17380 pcs 168 / 500 hrs 4 lots 328 pcs 1000 hrs (Note A*) 77+5 pcs / lot 168 / 500 hrs 4 lots 328 pcs 1000 hrs (Note A*) 77+5 pcs / lot 100 hrs Standard: 81 lots Green: 16 lots HTGB HTRB HAST Pressure Pot Temperature Cycle Temp = 150°c , Vds=80% of Vdsmax 130 +/- 2°c , 85%RH, 33.3 psi, Vgs = 80% of Vgs max 121°c , 29.7psi, 100%RH -65°c to 150°c , air to air 96 hrs 250 / 500 cycles (Note B**) Standard: 83 lots Green: 20 lots (Note B**) Standard: 87 lots Green: 29 lots (Note B**) Number of Failures 0 0 0 5335 pcs 0 50+5 pcs / lot 5665 pcs 0 50+5 pcs / lot 6380 pcs 0 50+5 pcs / lot 3 III. Result of Reliability Stress for AO4818B (Standard) & AO4818BL (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 Die shear 150°c 0hr 10 10 0 Note A: The HTGB and HTRB reliability data presents total of available AO4818B and AO4818BL burn-in data up to the published date. Note B: The pressure pot, temperature cycle and HAST reliability data for AO4818B and AO4818BL comes from the AOS generic package qualification data. IV. Reliability Evaluation FIT rate (per billion): 32 MTTF = 3567years In general, 500 hrs of HTGB, 150 deg C accelerated stress testing is equivalent to 15 years of lifetime at 55 deg C operating conditions (by applying the Arrhenius equation with an activation energy of 0.7eV and 60% of upper confidence level on the failure rate calculation). AOS reliability group also routinely monitors the product reliability up to 1000 hr at and performs the necessary failure analysis on the units failed for reliability test(s). The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in sample size of the selected product (AO4818B). Failure Rate Determination is based on JEDEC Standard JESD 85. FIT means one failure per billion hours. Failure Rate = Chi2 x 109 / [2 (N) (H) (Af)] = 1.83 x 109 / [2 (4×164) (168) (258)] = 32 MTTF = 109 / FIT = 3.12 x 107hrs = 3567years 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 4 V. Quality Assurance Information Acceptable Quality Level for outgoing inspection: 0.1% for electrical and visual. Guaranteed Outgoing Defect Rate: < 25 ppm Quality Sample Plan: conform to Mil-Std-105D 5