AOS Semiconductor Product Reliability Report AO3424/AO3424L, rev B Plastic Encapsulated Device ALPHA & OMEGA Semiconductor, Inc 495 Mercury Drive Sunnyvale, CA 94085 U.S. Tel: (408) 830-9742 www.aosmd.com Apr 19, 2006 1 This AOS product reliability report summarizes the qualification result for AO3424. 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 AO3424 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 AO3424 uses advanced trench technology to provide excellent RDS(ON), very low gate charge and operation with gate voltages as low as 2.5V. This device is suitable for use as a load switch or in PWM applications. Standard Product AO3424 is Pb-free (meets ROHS & Sony 259 specifications). AO3424L is a Green Product ordering option. AO3424 and AO3424L 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 2 ID 2 IDM 8 A 1.4 PD W 0.9 TJ, TSTG -55 to 150 Symbol T ≤ 10s SteadyState SteadyState RθJA RθJL °C Typ Max Units 70 90 °C/W 100 125 °C/W 63 80 °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 AO3424 Standard sub-micron low voltage N channel process 3 leads SOT Copper with Solder Plate Ag epoxy Au 2mils Epoxy resin with silica filler 90/10 UL-94 V-0 Ti / Ni / Ag Up to Level 1 * AO3424L (Green Compound) Standard sub-micron low voltage N channel process 3 leads SOT Copper with Solder Plate Ag epoxy Au 2 mils 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 AO3424 (Standard) & AO3424L (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: 32 lots Green: 19 lots 7535 pcs 0 5 lots 410 pcs 0 HTGB 168 / 500 hrs (Note A*) 77+5 pcs / lot 5 lots (Note A*) 410 pcs 1000 hrs HTRB Temp = 150°c , Vds=80% of Vdsmax 168 / 500 hrs Pressure Pot Temperature Cycle 130 +/- 2°c , 85%RH, 33.3 psi, Vgs = 80% of Vgs max 100 hrs 121°c , 29.7psi, RH=100% 96 hrs -65°c to 150°c , air to air, 250 / 500 cycles 0 77+5 pcs / lot 1000 hrs HAST Number of Failures Standard: 32 lots Green: 16 lots (Note B**) Standard: 27 lots Green: 14 lots (Note B**) Standard: 29 lots Green: 19 lots (Note B**) 2640 pcs 0 50+5 pcs / lot 2255 pcs 0 50+5 pcs / lot 2640 pcs 0 50+5 pcs / lot 3 III. Result of Reliability Stress for AO3424 (Standard) & AO3424L (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 AO3424 and AO3424L burn-in data up to the published date. Note B: The pressure pot, temperature cycle and HAST reliability data for AO3424 and AO3424L comes from the AOS generic package qualification data. IV. Reliability Evaluation FIT rate (per billion): 4.8 MTTF = 23782years In general, 500 hrs of HTGB, 150 deg C accelerated stress testing is equivalent to 15 years of lifetime at 55deg 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 (AO3424). 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 / [2 (164) (500) (258) +2 (4×164) (1000) (258)] = 4.8 9 8 MTTF = 10 / FIT = 2.08 x 10 hrs =23782years 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