Reliability Report

AOS Semiconductor
Product Reliability Report
AOT2500L,
rev A
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
www.aosmd.com
1
This AOS product reliability report summarizes the qualification result for AOT2500L. 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 AOT2500L passes AOS quality and
reliability requirements.
Table of Contents:
I.
II.
III.
IV.
V.
Product Description
Package and Die information
Environmental Stress Test Summary and Result
Reliability Evaluation
Appendix: Test data
I. Product Description:
The AOT2500L uses Trench MOSFET technology that is uniquely optimized to provide the most
efficient high frequency switching performance. Both conduction and switching power losses are
minimized due to an extremely low combination of RDS(ON), Ciss and Coss. 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:
Process
Package Type
Lead Frame
Die Attach
Bonding
Mold Material
Moisture Level
AOT2500L
Standard sub-micron
150V N-Channel MOSFET
TO220
Bare Cu
Soft solder
Al wire
Epoxy resin with silica filler
Up to Level 1
2
III. Result of Reliability Stress for AOT2500L
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
-
12 lots
168hrs
500 hrs
1000 hrs
2 lots
6 lots
Temp = 150°c ,
Vds=80% of
Vdsmax
168hrs
500 hrs
1000 hrs
2 lots
6 lots
77 pcs / lot
HAST
130°c , 85%RH,
33.3 psi, Vds =
80% of Vdsmax
96 hrs
9 lots
Pressure Pot
121°c , 29.7psi,
RH=100%
96 hrs
HTGB
HTRB
Temperature
Cycle
-65°c to 150°c ,
air to air,
250 / 500
cycles
Lot
Attribution
Total
Sample size
Number
of
Failures
Reference
Standard
2541pcs
0
JESD22A113
616pcs
0
JESD22A108
0
JESD22A108
693pcs
0
JESD22A110
(Note A*)
12 lots
77 pcs / lot
924pcs
0
JESD22A102
(Note A*)
77 pcs / lot
0
JESD22A104
77 pcs / lot
616pcs
12 lots
(Note A*)
924pcs
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): 3.27
MTTF = 34906 years
The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in
sample size of the selected product (AOT2500L). Failure Rate Determination is based on JEDEC
Standard JESD 85. FIT means one failure per billion hours.
2
9
Failure Rate (FIT) = Chi x 10 / [2 (N) (H) (Af)]
9
= 1.83 x 10 / [2x (4x77x500 +12x77x1000) x259] = 3.27
9
8
MTTF = 10 / FIT = 3.06 x 10 hrs = 34906 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:
55 deg C
70 deg C
85 deg C
100 deg C
115 deg C
Af
259
87
32
13
5.64
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
130 deg C
150 deg C
2.59
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