Reliability Report

AOS Semiconductor
Product Reliability Report
AOT404/AOT404L,
rev A
Plastic Encapsulated Device
ALPHA & OMEGA Semiconductor, Inc
495 Mercury Drive
Sunnyvale, CA 94085
U.S.
Tel: (408) 830-9742
www.aosmd.com
Mar 7, 2005
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This AOS product reliability report summarizes the qualification result for AOT404. 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 AOT4 04 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.
V.
Product Description
Package and Die information
Environmental Stress Test Summary and Result
Reliability Evaluation
Quality Assurance Information
I. Product Description:
The AOT404 uses advanced trench technology and design to provide excellent R DS (ON) with low gate
charge. This device is suitable for use in high voltage synchronous rectification, load switching and general
purpose applications. AOT404L (Green Product) is offered in a Lead Free package.
Absolute Maximum Ratings TA=25°C unless otherwise noted
Parameter
Symbol
Maximum
Units
Drain-Source Voltage
VDS
105
V
Gate-Source Voltage
VGS
±25
V
TA=25°C
Continuous Drain
G
Current
TA=100°C
Pulsed Drain Current
Avalanche Current
C
C
TA=25°C
B
Power Dissipation
Junction and Storage
Temperature Range
40
ID
IDM
100
IAR
20
Maximum Junction-to-Case
A
100
PD
TA=100°C
Thermal Characteristics
Parameter
Maximum Junction-toAmbient
A
28
W
50
TJ , TSTG
SteadyState
SteadyState
-55 to175
°C
Symbol
Typ
Max
Units
RθJA
50
60
°C/W
RθJL
1
1.5
°C/W
2
II. Die / Package Information:
Process
Package Type
Lead Frame
Die Attach
Bond wire
Mold Material
Filler % (Spherical/Flake)
Flammability Rating
Backside Metallization
Moisture Level
AOT404
AOT404L (Green Compound)
Standard sub-micron
Standard sub-micron
low voltage N channel process low voltage N channel process
3 leads TO220
3 leads TO220
Copper with Ni pad
Copper with Ni pad
Soft solder
Soft solder
Al wire, 5&15 mils
Al wire, 5&15 mils
Epoxy resin with silica filler
Epoxy resin with silica filler
50/50
100/0
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 AOT404 (Standard) & AOT404L (Green)
Test Item
Test Condition
Time
Point
Solder
Reflow
Precondition
HTGB
Normal: 1hr PCT+3
cycle IR reflow@240 °c
(260° c for Green)
Temp = 150 C,
Vgs=100% of Vgsmax
HTRB
HAST
Pressure Pot
Temperature
Cycle
Temp = 150 C, Vds=80%
of Vdsmax
Lot Attribution
Total
Sample
size
0hr
Normal: 9 lots
1210pcs
168 / 500
hrs
Normal: 2 lots
164pcs
1000 hrs
(Note A*)
168 / 500
hrs
Normal: 2 lots
1000 hrs
(Note A*)
130 +/- 2 C, 85%, 33.3
psi, Vgs = 80% of Vgs
max
100 hrs
121 C, 15+/-1 PSIG,
RH=100%
96 hrs
-65 to 150 deg C, air to
air, 0.5hr per cycle
250 / 500
cycles
Number
of
Failures
0
0
77+5 pcs /
lot
164pcs
0
77+5 pcs /
lot
Normal: 8 lots
440pcs
0
Normal: 9 lots
50+5 pcs /
lot
495pcs
0
Normal: 5 lots
50+5 pcs /
lot
275pcs
0
50+5 pcs /
lot
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III. Result of Reliability Stress for AOT404 (Standard) & AOT404L (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
230° C
5 sec
15
15 leads
0
Die shear
150°C
0hr
10
10
0
Note A: The HTGB and HTRB reliability data presents total of available AOT404 and AOT404L
burn-in data up to the published date.
IV. Reliability Evaluation
FIT rate (per billion): 14.4
MTBF = 7927 years
500 hrs of HTGB, 150 deg C accelerated stress testing is equivalent to 15 years of lifetime at 55
deg C operating conditions (by applying the Arrhenius equation with activation energy of 0.7eV
and 60% of upper confidence level on the failure rate calculation). AOS reliability group also
routinely monitors the product reliability up to 1000 hr at and performs the necessary failure
analysis on the units failed for reliability test(s).
The presentation of FIT rate for the individual product reliability is restricted by the actual burn-in
sample size of the selected product (AOT404). Failure Rate Determination is based on JEDEC
Standard JESD 85. FIT means one failure per billion hours.
2
9
/ [2 (N) (H) (Af)]
= 1.83 x 10 / [2 (164) (500) (258.24)+ 2 (164) (1000) (258.24)] = 14.4
7
Failure Rate = Chi x 10
9
9
MTBF = 10 / FIT =6.9x 10 hrs = 7927years
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 = 55C)
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 = Boltznan’s constant, 8.617164 X 10 E-5V / K
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V. Quality Assurance Information
Acceptable Quality Level for outgoing inspection: 0.1% for electrical and visual.
Guaranteed Outgoing Defect Rate: < 25 ppm
Quality Sample Plan: conform to Mil-Std-105D
Contacts:
Wei Liu, Engineer of Failure Analysis and Reliability
[email protected]
Fred Chang, Manager of Failure Analysis and Reliability
[email protected]
Wilson Ma, Senior Director of Quality Assurance
[email protected]
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