Reliability Report

AOS Semiconductor
Product Reliability Report
AO4240,
rev A
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
www.aosmd.com
This AOS product reliability report summarizes the qualification result for AO4240.
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 AO4240
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 AO4240 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 "Schottky style" soft recovery body diode.
- RoHS Compliant
- Halogen Free
Detailed information refers to datasheet.
II. Die / Package Information:
AO4240
Standard sub-micron
40V N channel
Package Type
SO8
Lead Frame
Cu
Die Attach
Ag Epoxy
Bonding
Cu wire
Mold Material
Epoxy resin with silica filler
MSL (moisture sensitive level) Level 1 based on J-STD-020
Process
Note * based on information provided by assembler and mold compound supplier
III. Result of Reliability Stress for AO4240
Test Item
Test Condition
Time
Point
MSL
Precondition
168hr 85°c
/85%RH +3 cycle
reflow@260°c
HTGB
Temp = 150 °c,
Vgs=100% of
Vgsmax
HTRB
HAST
Pressure Pot
Temperature
Cycle
Temp = 150 °c,
Vds=80% of
Vdsmax
Lot
Attribution
Total
Sample
size
Number
of
Failures
-
29 lots
3575pcs
0
JESD22A113
168hrs
500 hrs
1000 hrs
2 lots
385pcs
0
JESD22A108
0
JESD22A108
880pcs
0
JESD22A110
168hrs
500 hrs
1000 hrs
3 lots
(Note A*)
2 lots
3 lots
(Note A*)
Standard
77pcs / lot
385pcs
77pcs / lot
130 +/- 2°°c,
85%RH, 33.3 psi,
Vgs = 100% of
Vgs max
121°°c, 29.7psi,
RH=100%
100 hrs
16 lots
96 hrs
(Note A*)
20 lots
55 pcs / lot
1100pcs
0
JESD22A102
-65°°c to 150°°c,
air to air
250 / 500
cycles
(Note A*)
29 lots
55 pcs / lot
1595pcs
0
JESD22A104
(Note A*)
55 pcs / lot
Note A: The reliability data presents total available generic data up to the published date.
IV. Reliability Evaluation
FIT rate (per billion): 7
MTTF = 16536 years
The presentation of FIT rate for the individual product reliability is restricted by the actual
burn-in sample size of the selected product (AO4240). Failure Rate Determination is based
on JEDEC Standard JESD 85. FIT means one failure per billion hours.
2
9
Failure Rate = Chi x 10 / [2 (N) (H) (Af)]
9
= 1.83 x 10 / [2x (4x77x168+6x77x1000) x258] = 7
9
8
MTTF = 10 / FIT = 1.45 x 10 hrs = 16536 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
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
-5
K = Boltzmann’s constant, 8.617164 X 10 eV / K