Reliability Report

AOS Semiconductor
Product Reliability Report
AOD254,
rev A
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
www.aosmd.com
1
This AOS product reliability report summarizes the qualification result for AOD254. 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 AOD254 passes AOS quality and
reliability requirements.
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 AOD254 uses trench MOSFET technology that is uniquely optimized to provide the most
efficient high frequency switching performance. Power losses are minimized due to an extremely
low combination of RDS(ON) and Crss. In addition, switching behavior is well controlled with a soft
recovery body diode. This device is ideal for boost converters and synchronous rectifiers for
consumer, telecom, industrial power supplies and LED backlighting.
II. Die / Package Information:
AOD254
Standard sub-micron
Middle voltage N channel process
Package Type
TO252
Lead Frame
Bare Cu
Die Attach
Soft solder
Bonding
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 AOD254
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
-
9 lots
168hrs
500 hrs
1000 hrs
6 lots
Temp = 150°c ,
Vds=80% of
Vdsmax
168hrs
500 hrs
1000 hrs
HTGB
Lot
Attribution
Total
Sample size
Number
of
Failures
Reference
Standard
1210pcs
0
JESD22A113
462pcs
0
JESD22A108
0
JESD22A108
495pcs
0
JESD22A110
0
JESD22A102
0
JESD22A104
77 pcs / lot
HTRB
385pcs
5 lots
77 pcs / lot
HAST
Pressure Pot
Temperature
Cycle
130 +/- 2°c ,
85%RH, 33.3 psi,
Vgs = 100% of
Vgs max
121°c , 29.7psi,
RH=100%
-65°c to 150°c ,
air to air,
100 hrs
9 lots
96 hrs
(Note A*)
5 lots
55 pcs / lot
275pcs
(Note A*)
55 pcs / lot
250 / 500
cycles
8 lots
(Note A*)
440pcs
55 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): 8
MTTF = 13632 years
The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in
sample size of the selected product (AOD254). Failure Rate Determination is based on JEDEC
Standard JESD 85. FIT means one failure per billion hours.
2
9
9
Failure Rate = Chi x 10 / [2 (N) (H) (Af)] = 1.83 x 10
9
8
MTTF = 10 / FIT = 1.19 x 10 hrs = 13632 years
/ [2x (11x77x500) x258] = 8
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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