Reliability Report

AOS Semiconductor
Product Reliability Report
AO4442/AO4442L,
rev A
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
495 Mercury Drive
Sunnyvale, CA 94085
U.S.
Tel: (408) 830-9742
www.aosmd.com
This AOS product reliability report summarizes the qualification result for AO4442.
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 AO4442
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 AO4442 uses advanced trench technology to provide excellent RDS(ON), low gate
charge and operation with gate voltages from 4.5V to 25V. This device is suitable for use as a
load switch or in PWM applications. Standard Product AO4442 is Pb-free (meets ROHS &
Sony 259 specifications). AO4442L is a Green Product ordering option. AO4442 and
AO4442L are electrically identical.
II. Die / Package Information:
AO4442
AO4442L (Green Compound)
Process
Standard sub-micron
Low voltage N channel
Package Type
8 lead SOIC
Lead Frame
Cu, S/pad, Ag spot
Die Attach
Ag epoxy
Bond wire
Au 2mils
Mold Material
Epoxy resin with silica filler
Flammability Rating
UL-94 V-0
Backside Metallization Ti / Ni / Ag
Moisture Level
Up to Level 1 *
Standard sub-micron
Low voltage N channel
8 lead SOIC
Cu, S/pad, Ag spot
Ag epoxy
Au 2mils
Epoxy resin with silica filler
UL-94 V-0
Ti / Ni / Ag
Up to Level 1*
Note * based on information provided by assembler and mold compound supplier
III. Result of Reliability Stress for AO4442 (Standard) & AO4442L (Green)
Test Item
Test Condition
Time Point
Solder
Reflow
Precondition
Standard: 1hr PCT+3
cycle [email protected]°°c
Green: 168hr 85°°c
/85%RH +3 cycle
[email protected]°°c
Temp = 150°°c,
Vgs=100% of Vgsmax
-
HTGB
168 hrs
500 hrs
1000 hrs
Lot Attribution
Standard: 83 lots
Green: 29 lots
1 lot
(Note A*)
HTRB
Temp = 150°°c,
Vds=80% of Vdsmax
168 hrs
500 hrs
1000 hrs
1 lot
(Note A*)
HAST
Pressure Pot
130 +/- 2°°c, 85%RH,
33.3 psi, Vgs = 80% of
Vgs max
121°°c, 29.7psi,
RH=100%
100 hrs
Standard: 81 lots
Green: 16 lots
Total
Sample size
Number
of
Failures
17380 pcs
0
82 pcs
0
77+5 pcs / lot
82 pcs
0
77+5 pcs / lot
5335 pcs
0
50+5 pcs / lot
96 hrs
(Note B**)
Standard: 83 lots
Green: 20 lots
5665 pcs
0
50+5 pcs / lot
Temperature
Cycle
-65°°c to 150°°c,
air to air
250 / 500
cycles
(Note B**)
Standard: 87 lots
Green: 29 lots
6380 pcs
50+5 pcs / lot
(Note B**)
0
III. Result of Reliability Stress for AO4442 (Standard) & AO4442L (Green)
Continues
DPA
Internal Vision
Cross-section
X-ray
CSAM
NA
5
5
5
5
5
5
0
NA
5
5
0
Bond
Integrity
Room Temp
150°°c bake
150°°c bake
0hr
250hr
500hr
40
40
40
40 wires
40 wires
40 wires
0
Solderability
245°°C
5 sec
15
15 leads
0
Note A: The HTGB and HTRB reliability data presents total of available AO4442 and
AO4442L burn-in data up to the published date.
Note B: The pressure pot, temperature cycle and HAST reliability data for AO4442 and
AO4442L comes from the AOS generic package qualification data.
IV. Reliability Evaluation
FIT rate (per billion): 128
MTTF = 887 years
The presentation of FIT rate for the individual product reliability is restricted by the actual
burn-in sample size of the selected product (AO4442). 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
6
MTTF = 10 / FIT =7.77 x 10 hrs = 887 years
/ [2 x 164 x 168 x 258] = 128
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