AOS Semiconductor Product Reliability Report AO7401/AO7401L, rev B Plastic Encapsulated Device ALPHA & OMEGA Semiconductor, Inc 495 Mercury Drive Sunnyvale, CA 94085 U.S. Tel: (408) 830-9742 www.aosmd.com Dec 14, 2005 1 This AOS product reliability report summarizes the qualification result for AO7401. 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 AO7401 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 AO7401 uses advanced trench technology to provide excellent RDS(ON), low gate charge, and operation with gate voltages as low as 2.5V, 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. Standard Product AO7401 is Pb-free (meets ROHS & Sony 259 specifications). AO7401L is a Green Product ordering option. AO7401 and AO7401L are electrically identical. Absolute Maximum Ratings TA=25°C unless otherwise noted Parameter Symbol Maximum Units Drain-Source Voltage VDS -30 V Gate-Source Voltage VGS ±12 V Continuous Drain Current TA=25°C TA=70°C Pulsed Drain Current TA=25°C Power Dissipation TA=70°C Junction and Storage Temperature Range Thermal Characteristics Parameter Maximum Junction-toAmbient Maximum Junction-toAmbient Maximum Junction-to-Lead -1.2 ID -1.0 IDM -10 0.35 PD W 0.22 TJ, TSTG -55 to 150 Symbol T ≤ 10s SteadyState SteadyState A RθJA RθJL °C Typ Max Units 300 360 °C/W 350 425 °C/W 280 320 °C/W 2 II. Die / Package Information: Process Package Type Lead Frame Die Attach Bond wire Mold Material Flammability Rating Backside Metallization Moisture Level AO7401 Standard sub-micron Low voltage P channel process 3 leads SC-70 Copper with Solder Plate Ag epoxy Au 2mils Epoxy resin with silica filler UL-94 V-0 Ti / Ni / Ag Up to Level 1 * AO7401L (Green Compound) Standard sub-micron Low voltage P channel process 3 leads SC-70 Copper with Solder Plate Ag epoxy Au 2 mils 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 AO7401 (Standard) & AO7401L (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: 3 lots Green: 3 lots 990 pcs 4 lots 328 pcs HTGB 168 / 500 hrs (note A*) 1000 hrs HTRB Temp = 150°c , Vds=80% of Vdsmax 168 / 500 hrs 4 lots (note A*) 1000 hrs HAST Pressure Pot Temperature Cycle 130 +/- 2°c , 85%RH, 33.3 psi, Vgs = 80% of Vgs max 121°c , 15+/-1 PSIG, RH=100% -65°c to 150°c , air to air, 0.5hr per cycle 100 hrs 96 hrs 250 / 500 cycles Standard: 3 lots Green: 3 lots (note B**) Standard: 3 lots Green: 3 lots (note B**) Standard: 3 lots Green: 3 lots (note B**) Number of Failures 0 0 77+5 pcs / lot 328 pcs 0 77+5 pcs / lot 330 pcs 0 50+5 pcs / lot 330 pcs 0 50+5 pcs / lot 330 pcs 0 50+5 pcs / lot 3 III. Result of Reliability Stress for AO7401 (Standard) & AO7401L (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 AO7401 and AO7401L burn-in data up to the published date. Note B: The pressure pot, temperature cycle and HAST reliability data for AO7401 and AO7401L comes from the AOS generic package qualification data. IV. Reliability Evaluation FIT rate (per billion): 11.7 MTTF = 9757 years 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 (AO7401). 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) (168) (258) + 2 (164) (500) (258) + + 2 (164) (1000) (258)] = 11.7 MTTF = 109 / FIT =8.54 x 107hrs = 9757years 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