Reliability Report

AOS Semiconductor
Product Reliability Report
AO4940/AO4940L,
rev A
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
495 Mercury Drive
Sunnyvale, CA 94085
U.S.
Tel: (408) 830-9742
www.aosmd.com
1
This AOS product reliability report summarizes the qualification result for AO4940. 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 AO4940 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.
I.
Product Description
Package and Die information
Environmental Stress Test Summary and Result
Reliability Evaluation
Product Description:
The AO4940/L uses advanced trench technology to provide excellent RDS(ON) and low gate charge.
The two MOSFETs make a compact and efficient switch and synchronous rectifier combination
for use in DC-DC converters. A monolithically integrated Schottky diode in parallel with the
synchronous MOSFET to boost efficiency further. Standard Product AO4940 is Pb-free (meets
ROHS & Sony 259 specifications).
- RoHS Compliant
- AO4940L is Halogen Free
2
II. Die / Package Information:
Process
Package Type
Lead Frame
Die Attach
Bond wire
Mold Material
Flammability Rating
Backside Metallization
Moisture Level
AO4940
Standard sub-micron
Low voltage N channel process
8 leads SOIC
Cu, D/pad, Ag spot
Ag epoxy
G: Au 1.3 mils; S: Cu 2mils
Epoxy resin with silica filler
UL-94 V-0
Ti / Ni / Ag
Up to Level 1 *
AO4940L (Green Compound)
Standard sub-micron
Low voltage N channel process
8 leads SOIC
Cu, D/pad, Ag spot
Ag epoxy
G: Au 1.3 mils; S: Cu 2mils
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 AO4940 (Standard) & AO4940L (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
-
Standard: 83 lots
Green: 29 lots
17380 pcs
0
82 pcs
0
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,
RH=100%
-65°c to 150°c ,
air to air
168 / 500
hrs
1 lot
1000 hrs
(Note A*)
168 / 500
hrs
1 lot
1000 hrs
(Note A*)
100 hrs
Standard: 81 lots
Green: 16 lots
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
77+5 pcs /
lot
82 pcs
0
77+5 pcs /
lot
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 AO4940 (Standard) & AO4940L (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
Note A: The HTGB and HTRB reliability data presents total of available AO4940 and AO4940L
burn-in data up to the published date.
Note B: The pressure pot, temperature cycle and HAST reliability data for AO4940 and AO4940L
comes from the AOS generic package qualification data.
IV. Reliability Evaluation
FIT rate (per billion): 128
MTTF = 887 years
4