Reliability Report

AOS Semiconductor
Product Reliability Report
AOT500,
rev A
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
495 Mercury Drive
Sunnyvale, CA 94085
U.S.
Tel: (408) 830-9742
www.aosmd.com
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This AOS product reliability report summarizes the qualification result for AOT500. 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 AOT500 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:
AOT500 uses an optimally designed temperature compensated gate-drain zener clamp. Under
over voltage conditions, the clamp activates and turns on the MOSFET, safely dissipating the
energy in the MOSFET. The built in resistor guarantees proper clamp operation under all circuit
conditions, and the MOSFET never goes into avalanche breakdown. Advanced trench technology
provides excellent low Rdson, gate charge and body diode characteristics, making this device
ideal for motor and inductive load control applications.
Standard Product AOT500 is Pb-free (meets ROHS & Sony 259 specifications).
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II. Die / Package Information:
Process
Package Type
Lead Frame
Die Attach
Bond wire
Mold Material
Flammability Rating
Backside Metallization
Moisture Level
AOT500
Standard sub-micron
Low voltage N channel process
3 leads TO220
Cu, Ni pad, Ni lead
Soft solder
Al 5&15mils
Soft solder
UL-94 V-0
Ti / Ni / Ag
Up to Level 1 *
Note * based on info provided by assembler and mold compound supplier
III. Result of Reliability Stress for AOT500
Test Item
Test Condition
Time
Point
Solder
Reflow
Precondition
HTGB
168hr 85°c
/85%RH +3 cycle
reflow@260°c
Temp = 150°c ,
Vgs=100% of Vgsmax
-
168hrs
500 hrs
1000 hrs
Lot Attribution
Total
Sample
size
8 lots
990pcs
0
164pcs
0
77+5 pcs /
lot
164pcs
0
77+5 pcs /
lot
275pcs
0
50+5 pcs /
lot
275pcs
0
50+5 pcs /
lot
440pcs
0
2 lots
(Note A*)
HTRB
HAST
Pressure Pot
168hrs
500 hrs
1000 hrs
2 lots
130°c , 85%RH,
33.3 psi, Vgs = 80% of
Vgs max
100 hrs
(Note A*)
5 lots
121°c , 29.7psi,
RH=100%
96 hrs
Temp = 150°c ,
Vds=80% of Vdsmax
(Note B**)
5 lots
(Note B**)
Temperature
Cycle
-65°c to 150°c ,
air to air
250 / 500
cycles
Number
of
Failures
8 lots
(Note B**)
50+5 pcs /
lot
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III. Result of Reliability Stress for AOT500
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 AOT500 burn-in data up
to the published date.
Note B: The pressure pot, temperature cycle and HAST reliability data for AOT500 comes from
the AOS generic package qualification data.
IV. Reliability Evaluation
FIT rate (per billion): 11
MTTF = 10558 years
The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in
sample size of the selected product (AOT500). Failure Rate Determination is based on JEDEC
Standard JESD 85. FIT means one failure per billion hours.
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9
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Failure Rate = Chi x 10 / [2 (N) (H) (Af)] = 1.83 x 10
9
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MTTF = 10 / FIT = 9.25 x 10 hrs =10558 years
/ [2x 2x164x1000x258] = 11
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
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Tjs = Stressed junction temperature in degree (Kelvin), K = C+273.16
Tju =The use junction temperature in degree (Kelvin), K = C+273.16
k = Boltzmann’s constant, 8.617164 X 10-5eV/K
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