Reliability stress tests(on-semiconduct),FYI

Reliability stress tests
(on-semiconductor)
1.
AUTOCLAVE
Autoclave is an environmental test which measures device resistance to moisture penetration and the resultant effects of galvanic corrosion. Autoclave is a highly accelerated and destructive test.
Typical test condition :

TA=121℃ , RH.=100%, P=1atmosphere(15PSIG), t=24 to 240 hours.
Common failure modes:

Parametric shifts, high leakage and/or catastrophic failure .
Common failure mechanisms:

Die corrosion or contaminants such as foreign material on or within the package materials. Poor package seal.
2.
Highly accelerated stress test:
Highly accelerated stress test uses a pressurized environment to produce extremely severe temperature, humidity and bias conditions, H.A.S.T. accelerates the same failure mechanisms as high humidity high temperature bias.
Typical test conditions:
Ta=130℃, RH=85% to 95%, p=2 atmospheres, bias=80% to 100% of data Book maximum rating, t= 96 to 240 hours.
**
Common failure modes:**

Parametric shifts, high leakage and/or catastrophic failure.
**
Common failure mechanisms:**

Die corrosion or contaminants such as foreign material on or within the package materials. Poor package sealing.
3.
High humidity high temperature bias.
This is environmental test designed to measure the moisture resistance of plastic encapsulated devices. A bias is applied to crate an electrolytic cell necessary to accelerate corrosion of the die metallization with time, this is catastrophically destructive test.
Typical test cognition:
Ta=85 to 95℃, RH=85% to 95%,
bias=80% to 100% of data Book maximum rating, t= 96 to 1008 hours
Common failure modes:

Parametric shifts, high leakage and/or catastrophic failure.
Common failure mechanisms:

Die corrosion or contaminants such as material on or within the package materials. Poor package sealing.
4.
**
High temperature forward bias:**
This test is designed to measure the stability of devices under a forward
bias condition at high temperature .
Typical test condition :

Ta=85 to 100℃, bias=80% to 100% of data Book maximum rating, t= 120 to 1008 hours.
Common failure modes:

Parametric shifts in repetitive peak off state and reverse currents, gate trigger

current and voltage.
5.
High temperature gate bias
This test is designed to electrically stress the gate oxide under a bias condition at high temperature.
Typical test condition:
TA=150℃, BIAS=80% OF data book maximum rating, t=120 to 1008 hours.
Common failure modes:

Parametric shifts in gate leakage and gate threshold (開始, 極限) voltage.
Common failure mechanism :

Random oxide defects and ionic contamination(沾污)
6.
High temperature reverse bias
the purpose of this test is to align mobile ions by means of temperature and voltage stress to form a high-current leakage path between two or more junctions.
Typical test cognition:
TA=85℃ to 150℃, bias=80% to 100% of data book maximum rating, t=120 to 1008 hours .
**
Common failure modes:**

Parametric shifts in leakage and gain
**
Common failure mechanism :**

Ionic contamination on surface or under the metallization of die.
7.
High temperature store life
High temperature store life testing is performed to accelerate failure mechanisms which are thermally activated through the application of extreme temperatures.
Typical test condition:
TA=125℃ to 200℃, no bias, t=24 to 1008 hours.
**
Common failure modes:**

Parametric shifts in leakage and gain.
**
Common failure mechanisms:**

Bulk die and diffusion defects.
8.
Intermittent(斷續)operating life
The purpose of this test is the same as operating life in addition to checking the integrity of both wire and die bonds by means of thermal stressing.
Typical test conditions:
TA=25℃, pd=data book maximum rating, Ton=Toff=△Tj of 125℃ to 175℃, t=1000 to 15000 cycles.
**
Common failure modes:**


Parametric shifts and catastrophic (災難) failure.
**
Common failure mechanism:**

Foreign material , crack and bulk die defects, metallization , wire and die bond defects.
9.
Operating life
The purpose of this test is to evaluate the bulk stability of the die and to generate defects resulting from manufacturing aberrations(失常) that are manifested(