Reliability Report

AOS Semiconductor
Product Reliability Report
AO8808A/AO8808AL,
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 AO8808A/L.
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 AO8808A/Lpasses
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.
Product Description
Package and Die information
Environmental Stress Test Summary and Result
Reliability Evaluation
I. Product Description:
The AO8808A uses advanced trench technology to provide excellent RDS(ON), low gate charge
and operation with gate voltages as low as 1.8V while retaining a 12V VGS(MAX) rating. It is ESD
protected. Standard Product AO8808A is Pb-free (meets ROHS & Sony 259 specifications).
AO8808A and AO8808AL are electrically identical.
-RoHS Compliant
-AO8808AL is Halogen Free
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II. Die / Package Information:
Process
Package Type
Lead Frame
Die Attach
Bond wire
Mold Material
Flammability Rating
Backside Metallization
Moisture Level
AO8808A
AO8808AL (Green Compound)
Standard sub-micron
Low voltage N channel process
TSSOP-8
Cu, D/pad, Ag spot
Ag epoxy
S: Cu 2 mils; G: Au, 1mil
Epoxy resin with silica filler
UL-94 V-0
Ti / Ni / Ag
Up to Level 1 *
Standard sub-micron
low voltage N channel process
TSSOP-8
Cu, D/pad, Ag spot
Ag epoxy
S: Cu 2 mils; G: Au, 1mil
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 AO8808A (Standard) & AO8808AL (Green)
Test Item
Test Condition
Time
Point
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
-
HTGB
HTRB
Temp = 150°°c ,
Vds=80% of Vdsmax
168hrs
500 hrs
1000 hrs
168hrs
500 hrs
1000 hrs
HAST
130 +/- 2°°c , 85%RH,
33.3 psi, Vgs = 80% of
Vgs max
100 hrs
Pressure Pot
121°°c , 29.7psi,
RH=100%
96 hrs
Temperature
Cycle
-65°°c to 150°°c ,
air to air,
250 / 500
cycles
Lot Attribution
Standard: 11 lots
Green: 4 lots
1 lot
2 lots
(Note A*)
Total
Sample
size
1705 pcs
0
241 pcs
0
77 pcs / lot
241 pcs
1 lot
2 lots
(Note A*)
Number of
Failures
0
77 pcs / lot
Standard: 6 lots
Green: 4 lots
550 pcs
0
(Note B**)
Standard: 11 lots
Green: 4 lots
55 pcs / lot
825 pcs
0
(Note B**)
Standard: 3 lots
Green: 3 lots
55 pcs / lot
330 pcs
0
(Note B**)
55 pcs / lot
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III. Result of Reliability Stress for AO8808A (Standard) & AO8808AL (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 AO8808A/L burn-in data
up to the published date.
Note B: The pressure pot, temperature cycle and HAST reliability data for AO8808A/L comes
from the AOS generic package qualification data.
IV. Reliability Evaluation
FIT rate (per billion): 9
MTTF = 12392 years
The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in
sample size of the selected product (AOB414). Failure Rate Determination is based on JEDEC
Standard JESD 85. FIT means one failure per billion hours.
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9
9
Failure Rate = Chi x 10 / [2 (N) (H) (Af)] = 1.83 x 10
9
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MTTF = 10 / FIT = 1.09 x 10 hrs = 12392 years
/ [2x (4x77x500+2x77x1000) x258] = 9
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
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Tjs = Stressed junction temperature in degree (Kelvin), K = C+273.16
Tju =The use junction temperature in degree (Kelvin), K = C+273.16
k = Boltzmann’s constant, 8.617164 X 10-5eV/K
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