Reliability Report

AOS Semiconductor
Product Reliability Report
AOTF404/AOTF404L,
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 AOTF404. 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 AOTF404 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 AOTF404/L uses advanced trench technology and design to provide excellent RDS(ON) with low
gate charge. This device is suitable for use in high voltage synchronous rectification, load switching
and general purpose applications.
-RoHs Compliant
-AOTF404L is Halogen free
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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
AOTF404
AOTF404L (Green Compound)
Standard sub-micron
Standard sub-micron
Low voltage N channel process Low voltage N channel process
3 leads TO220FL
3 leads TO220FL
Bare Cu
Bare Cu
Soft solder
Soft solder
Al 5&15 mils
Al 5&15 mils
Epoxy resin with silica filler
Epoxy resin with silica filler
UL-94 V-0
UL-94 V-0
Ti / Ni / Ag
Ti / Ni / Ag
Up to Level 1 *
Up to Level 1*
Note * based on info provided by assembler and mold compound supplier
III. Result of Reliability Stress for AOTF404 (Standard) & AOTF404L (Green)
Test Item
Test Condition
Time
Point
Lot Attribution
Total
Sample
size
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
-
Standard: 11 lots
Green: 3 lots
2442pcs
0
231pcs
0
HTGB
168hrs
500 hrs
1000 hrs
Number
of
Failures
3 lots
77pcs / lot
(Note A*)
HTRB
Temp = 150°°c ,
Vds=80% of Vdsmax
168hrs
500 hrs
1000 hrs
231pcs
0
3 lots
77 pcs / lot
HAST
130 +/- 2°°c , 85%RH,
33.3 psi, Vgs = 80% of
Vgs max
100 hrs
(Note A*)
Standard : 5 lots
Green: 3 lots
Pressure Pot
121°°c , 29.7psi,
100%RH
96 hrs
Temperature
Cycle
-65°°c to 150°°c ,
air to air,
250 / 500
cycles
440pcs
0r
(Note B**)
Standard :11 lots
Green: 3 lots
55 pcs / lot
1078pcs
0
(Note B**)
Standard : 9 lots
Green: 3 lots
77 pcs / lot
924pcs
0
(Note B**)
77 pcs / lot
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III. Result of Reliability Stress for AOTF404 (Standard) & AOTF404L (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 AOTF404 and AOTF404L
burn-in data up to the published date.
Note B: The pressure pot, temperature cycle, HAST and HTS reliability data for AOTF404 and
AOTF404L comes from the AOS generic package qualification data.
IV. Reliability Evaluation
FIT rate (per billion): 8
MTTF = 14871 years
The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in
sample size of the selected product (AOTF404). Failure Rate Determination is based on JEDEC
Standard JESD 85. FIT means one failure per billion hours.
2
9
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Failure Rate = Chi x 10 / [2 (N) (H) (Af)] = 1.83 x 10
9
8
MTTF = 10 / FIT =1.30 x10 hrs = 14871 years
/ [2x6x77x1000x258] = 8
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
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