Reliability Report

AOS Semiconductor
Product Reliability Report
AO4620,
rev C
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
www.aosmd.com
This AOS product reliability report summarizes the qualification result for AO4620.
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 AO4620
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 AO4620 uses advanced trench technology MOSFETs to provide excellent RDS(ON) and
low gate charge. The complementary MOSFETs may be used in inverter and other
applications.
-RoHS Compliant
-Halogen Free
Detailed information refers to datasheet.
II. Die / Package Information:
AO4620
Standard sub-micron
Low voltage N+P channel
Package Type
8 lead SOIC
Lead Frame
Copper
Die Attach
Ag Epoxy
Bonding Wire
Au & Cu wire
Mold Material
Epoxy resin with silica filler
Flammability Rating
UL-94 V-0
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 AO4620
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
Temp = 150 °c,
Vgs=100% of
Vgsmax
-
29 lots
3575pcs
0
JESD22A113
168hrs
500 hrs
1000 hrs
154pcs
0
2 lots
JESD22A108
0
JESD22A108
880pcs
0
JESD22A110
(Note A*)
HTRB
Temp = 150 °c,
Vds=80% of
Vdsmax
168hrs
500 hrs
1000 hrs
HAST
Pressure Pot
Temperature
Cycle
77pcs / lot
154pcs
2 lots
(Note A*)
Standard
77pcs / lot
130 +/- 2°°c,
85%RH, 33.3 psi,
Vgs = 80% 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 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 (AO4620). 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
/ [2x4x77x500x258] = 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