AOS Semiconductor Product Reliability Report AO7800/AO7800L, rev B Plastic Encapsulated Device ALPHA & OMEGA Semiconductor, Inc 495 Mercury Drive Sunnyvale, CA 94085 U.S. Tel: (408) 830-9742 www.aosmd.com Aug 4, 2006 1 This AOS product reliability report summarizes the qualification result for AO7800/AO7800L. 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 AO7800/AO7800L 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. Product Description Package and Die information Environmental Stress Test Summary and Result Reliability Evaluation Quality Assurance Information I. Product Description: The AO7800 uses advanced trench technology to provide excellent RDS(ON), low gate charge and operation with gate voltages as low as 1.8V, in the small SOT323 footprint. It can be used for a wide variety of applications, including load switching, low current inverters and low current DC-DC converters. It is ESD protected. Standard Product AO7800 is Pb free (meets ROHS & Sony 259 specifications). AO7800L is a Green Product ordering option. AO7800 and AO7800L are electrically identical. Absolute Maximum Ratings TA=25°C unless otherwise noted Parameter Symbol Maximum Units Drain-Source Voltage VDS 20 V Gate-Source Voltage VGS ±8 V ID 0.9 Continuous Drain Current TA=25°C TA=70°C Pulsed Drain Current Power Dissipation TA=25°C TA=70°C Junction and Storage Temperature Range Thermal Characteristics Parameter Maximum JunctionT ≤ 10s to-Ambient Maximum JunctionSteadyto-Ambient State Maximum JunctionSteadyto-Lead State 0.7 IDM A 5 0.3 PD TJ, TSTG Symbol RθJA RθJL 0.19 W -55 to 150 °C Typ Max 360 415 400 460 300 350 Units °C/W 2 II. Die / Package Information: Process Package Type Lead Frame Die Attach Bondwire Mold Material Flammability Rating Backside Metallization Moisture Level AO7800 Standard sub-micron Low voltage N channel process SC-70 6L Alloy 42, Ag spot Silver epoxy 1.3mils Au wire Epoxy resin with silica filler UL-94 V-0 Ti / Ni / Ag Up to Level 1 * AO7800L (Green Compound) Standard sub-micron Low voltage N channel process SC-70 6L Alloy 42, Ag spot Silver epoxy 1.3mils Au wire Epoxy resin with silica filler 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 AO7800 (Standard) & AO7800L (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 /85RH +3 cycle reflow @260°c Temp = 150°c, Vgs=100% of Vgsmax 0hr Standard: 10 lots Green: 3 lots 1925 pcs 0 2 lots 164 pcs 0 HTGB 168 / 500 hrs (Note A*) Number of Failures 77+5 pcs / lot 1000 hrs HTRB Temp = 150°c, Vds=80% of Vdsmax 168 / 500 hrs 2 lots (Note A*) 164 pcs 0 77+5 pcs / lot 1000 hrs HAST Pressure Pot 130 +/- 2°c, 85%RH, 33.3 psi, Vgs = 80% of Vgs max 121°c, 29.7psi, 100%RH 100 hrs Standard: 6 lots Green: 3 lots 495 pcs 0 50+5 pcs / lot 96 hrs (Note B**) Standard: 10 lots Green: 3 lots 715 pcs 0 50+5 pcs / lot Temperature Cycle -65°c to 150°c, air to air, 250 / 500 cycles (Note B**) Standard: 10 lots Green: 3 lots 715 pcs 0 50+5 pcs / lot (Note B**) 3 III. Result of Reliability Stress for AO7800 (Standard) & AO7800L (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 230°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 AO7800 and AO7800L burn-in data up to the published date. Note B: The pressure pot, temperature cycle and HAST reliability data for AO7800L comes from the AOS generic green compound package qualification data. IV. Reliability Evaluation FIT rate (per billion): 11 MTTF = 10377 years 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 (AO7800). 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 (2×164) (1000) (258)] = 11 MTTF = 109 / FIT = 9.08 x 108hrs = 10377 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 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