Reliability Report

AOS Semiconductor
Product Reliability Report
AO4421,
rev C
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
www.aosmd.com
This AOS product reliability report summarizes the qualification result for AO4421.
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 AO4421
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 AO4421 combines advanced trench MOSFET -60V technology with a low resistance
package to provide extremely low RDS(ON). This device is ideal for load switch and battery
protection applications.
-RoHS Compliant
-Halogen Free
Detailed information refers to datasheet.
II. Die / Package Information:
AO4421
Standard sub-micron
Low voltage P channel
Package Type
SO8
Lead Frame
Copper
Die Attach
Ag Epoxy
Bonding Wire
Au wire
Mold Material
Epoxy resin with silica filler
MSL (moisture sensitive level) Level 1 based on J-STD-020
Process
III. Result of Reliability Stress for AO4421
Test Item
Test Condition
Time
Point
Lot
Attribution
Total
Sample
size
Number
of
Failures
MSL
Precondition
168hr 85°c
/85%RH +3 cycle
reflow@260°c
HTGB
-
33 lots
5929pcs
0
JESD22A113
Temp = 150 c,
Vgs=100% of
Vgsmax
168hrs
500 hrs
1000 hrs
231pcs
0
6 lots
4 lots
JESD22A108
Temp = 150 c,
Vds=80% of
Vdsmax
168hrs
500 hrs
1000 hrs
77pcs / lot
231pcs
0
JESD22A108
130 +/- 2c,
85%RH, 33.3 psi,
Vgs = 80% of
Vgsmax
121c, 29.7psi,
RH=100%
96 hrs
(Note A*)
20 lots
77pcs / lot
1540pcs
0
JESD22A110
96 hrs
(Note A*)
24lots
77 pcs / lot
1848pcs
0
JESD22A102
-65c to 150c,
air to air
250 / 500
cycles
(Note A*)
33 lots
77 pcs / lot
2541pcs
0
JESD22A104
(Note A*)
77 pcs / lot
(Note A*)
HTRB
HAST
Pressure Pot
Temperature
Cycle
6 lots
4 lots
Standard
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 (AO4421). 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 / [2 x (2x12x77x500+8x77x1000) x 259] = 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:
Af
55 deg C
70 deg C
85 deg C
100 deg C
115 deg C
130 deg C
150 deg C
259
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