Reliability Report

AOS Semiconductor
Product Reliability Report
AOD478,
rev C
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
www.aosmd.com
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This AOS product reliability report summarizes the qualification result for AOD478. 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 AOD478 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.
Product Description
Package and Die information
Environmental Stress Test Summary and Result
Reliability Evaluation
I. Product Description:
The AOD478 combines advanced trench MOSFET technology with a low resistance package to
provide extremely low RDS(ON). This device is ideal for boost converters and synchronous rectifiers
for consumer, telecom, industrial power supplies and LED backlighting.
-RoHS Compliant
-Halogen Free
Details refer to the datasheet.
II. Die / Package Information:
AOD478
Standard sub-micron
100V N channel MOSFET
Package Type
TO252
Lead Frame
Bare Cu
Die Attach
Soft solder
Bond
Al & Au wire
Mold Material
Epoxy resin with silica filler
Moisture Level
Up to Level 1 *
Note * based on info provided by assembler and mold compound supplier
Process
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III. Result of Reliability Stress for AOD478
Test Item
Test Condition
Time
Point
MSL
Precondition
168hr 85°c
/85%RH +3 cycle
reflow@260°c
Temp = 150°c ,
Vgs=100% of
Vgsmax
-
HTGB
HTRB
Temp = 150°c ,
Vds=80% of
Vdsmax
HAST
Pressure Pot
Temperature
Cycle
168hrs
500 hrs
1000 hrs
168hrs
500 hrs
1000 hrs
Lot
Attribution
Total
Sample size
Number
of
Failures
Reference
Standard
15 lots
2739pcs
0
JESD22A113
3 lots
6 lots
5 lots
(Note A*)
1078pcs
0
JESD22A108
3 lots
6 lots
5 lots
(Note A*)
1078pcs
0
JESD22A108
660pcs
0
JESD22A110
0
JESD22A102
0
JESD22A104
77 pcs / lot
77 pcs / lot
130 +/- 2°c ,
85%RH,
33.3 psi, Vgs =
100% of Vgs max
121°c , 29.7psi,
RH=100%
100 hrs
12 lots
96 hrs
(Note A*)
12lots
55 pcs / lot
924pcs
(Note A*)
77 pcs / lot
-65°c to 150°c ,
air to air,
250 / 500
cycles
15 lots
(Note A*)
1155pcs
77 pcs / lot
Note A: The reliability data presents total of available generic data up to the published date.
IV. Reliability Evaluation
FIT rate (per billion): 3
MTTF = 42154 years
The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in
sample size of the selected product (AOD478). Failure Rate Determination is based on JEDEC
Standard JESD 85. FIT means one failure per billion hours.
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Failure Rate = Chi x 10 / [2 (N) (H) (Af)]
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= 1.83 x 10 / [2x (6x77x168 +12x77x500 +10x77x1000) x258] = 3
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MTTF = 10 / FIT = 3.69 x 10 hrs = 42154 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
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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
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