AOS Semiconductor Product Reliability Report AO4704/AO4704L, rev C Plastic Encapsulated Device ALPHA & OMEGA Semiconductor, Inc 495 Mercury Drive Sunnyvale, CA 94085 U.S. Tel: (408) 830-9742 www.aosmd.com May 11, 2006 1 This AOS product reliability report summarizes the qualification result for AO4704. 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 AO4704 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 AO4704 uses advanced trench technology to provide excellent RDS(ON), shoot-through immunity and body diode characteristics. This device is suitable for use as a synchronous switch in PWM applications. The co-packaged Schottky Diode boosts efficiency further. AO4704 is Pbfree (meets ROHS & Sony 259 specifications). AO4704L is a Green Product ordering option. AO4704 and AO4704L are electrically identical. Absolute Maximum Ratings TA=25°C unless otherwise noted Parameter Symbol Mosfet Schottky Units Drain-Source Voltage VDS 30 V Gate-Source Voltage VGS ±12 V ID 13 Continuous Drain Current TA=25°C TA=70°C 10.4 Pulsed Drain Current IDM Schottky reverse voltage VKA Continuous Forward Current TA=25°C TA=70°C Pulsed Forward Current Power Dissipation TA=25°C TA=70°C Junction and Storage Temperature Range 30 3.2 IFM TJ, TSTG V 4.4 IF PD A 40 A 30 3.1 3.1 2 2 W -55 to 150 -55 to 150 °C 2 Thermal Characteristics MOSFET Maximum Junctiont ≤ 10s to-Ambient Maximum JunctionSteadyto-Ambient State Maximum JunctionSteadyto-Lead State Thermal Characteristics Schottky Maximum Junctiont ≤ 10s to-Ambient Maximum JunctionSteadyto-Ambient State Maximum JunctionSteadyto-Lead State Symbol Typ Max 28 40 54 75 RθJL 21 30 Symbol Typ Max 36 40 67 75 25 30 RθJA RθJA RθJL Units °C/W Units °C/W II. Die / Package Information: Process AO4704 AO4704L (Green Compound) Standard sub-micron Standard sub-micron low voltage N channel process low voltage N channel process Package Type Lead Frame Die Attach Bond wire Mold Material Filler % (Spherical/Flake) Flammability Rating Backside Metallization Moisture Level 8 lead SOIC Copper with Solder Plate Silver epoxy 2 mils Au wire Epoxy resin with silica filler 90/10 UL-94 V-0 Ti / Ni / Ag Up to Level 1 * 8 lead SOIC Copper with Solder Plate Silver epoxy 2 mils Au wire 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 3 III. Result of Reliability Stress for AO4704 (Standard) & AO4704L (Green) Test Item Test Condition Time Point Solder Reflow Precondition Standard: 1hr PCT+3 cycle reflow@260°c Green: 168hr 85°c /85%RH+3 cycles reflow@260°c Temp = 150°c, Vgs=100% of Vgsmax 0hr HTGB 168 / 500 hrs Lot Attribution Standard: 87 lots Green: 29 lots 5 lots (Note A*) Total Sample size Number of Failures 17380 pcs 0 410 pcs 0 77+5 pcs / lot 1000 hrs HTRB Temp = 150°c, Vds=80% of Vdsmax 168 / 500 hrs 5 lots (Note A*) 410 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, 15+/-1 PSIG, RH=100% 100 hrs Standard: 81 lots Green: 16 lots 5335 pcs 0 50+5 pcs / lot 96 hrs (Note B**) Standard: 83 lots Green: 20 lots 5665 pcs 0 50+5 pcs / lot Temperature Cycle DPA -65°c to 150°c , air to air, 250 / 500 cycles (Note B**) Standard: 87 lots Green: 29 lots 6380 pcs 0 50+5 pcs / lot Internal Vision Cross-section X-ray CSAM (Note B**) 5 5 5 5 5 5 0 NA 5 5 0 NA 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 AO4704 and AO4704L burn-in data up to the published date. Note B: The pressure pot, temperature cycle and HAST reliability data for AO4704 and AO4704L comes from the AOS generic package qualification data. 4 IV. Reliability Evaluation FIT rate (per billion): 11.7 MTTF = 9756 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 (AO4704). 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) + (164)×(500) (258)+ (164) × (1000) (258)] = 11.7 MTTF = 109 / FIT = 8.54 x 107 hrs = 9756 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 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