Reliability Report

AOS Semiconductor
Product Reliability Report
AOD458,
rev A
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
www.aosmd.com
1
This AOS product reliability report summarizes the qualification result for AOD458. 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 AOD458 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 AOD458 has been fabricated using an advanced high voltage MOSFET process that is
designed to deliver high levels of performance and robustness in popular AC-DC applications. By
providing low RDS(on), Ciss and Crss along with guaranteed avalanche capability this device can
be adopted quickly into new and existing offline power supply designs. 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:
AOD458
Standard sub-micron
Low voltage N channel process
Package Type
3 leads TO252
Lead Frame
Bare Cu
Die Attach
Soft solder
Bond wire
Al 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
2
III. Result of Reliability Stress for AOD458
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
Lot
Attribution
9 lots
168hrs
500 hrs
1000 hrs
168hrs
500 hrs
1000 hrs
1 lot
(Note A*)
Total
Sample size
Number
of
Failures
1210pcs
0
JESD22A113
77pcs
0
JESD22A108
0
JESD22A108
495pcs
0
JESD22A110
0
JESD22A102
0
JESD22A104
77 pcs / lot
77pcs
1 lot
(Note A*)
77 pcs / lot
130 +/- 2°c ,
85%RH,
33.3 psi, Vgs =
100% of Vgs max
121°c , 29.7psi,
RH=100%
100 hrs
9 lots
96 hrs
(Note A*)
5 lots
55 pcs / lot
275pcs
(Note A*)
55 pcs / lot
-65°c to 150°c ,
air to air,
250 / 500
cycles
8 lots
(Note A*)
Reference
Standard
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): 23
MTTF = 4957 years
The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in
sample size of the selected product (AOD458). 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
7
MTTF = 10 / FIT = 4.34 x 10 hrs = 4957 years
/ [2x2x77x1000x258] = 23
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
1
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
3