Pressure Cooker Tester – Pressure Cooker Test (PCT)

●	Equipment Model: WEW-PCT-350-515
●	Test Bucket: Round-shaped Bucket ∮250 mm x L400 mm
●	External Dimension: 650x 700 x 1050 mm (W * D * H)
●	Set Temperature: + 100 ℃ ~ + 135 ℃｜+ 100 ℃ ~ + 147 ℃ (Steam Temperature)
●	Humidity Range: 100% RH｜75 ~ 100% RH (47 ℃ degrees of humidity up to 75% RH)
●	Humidity Control Stability: ±1% RH
●	Pressure Application: 1.2~2.89 KG (include 1atm)
●	Time Range: 0 Hr ~ 9999 Hr
●	Pressure Time: 0.00kg ~ 1.04 Kg/cm2 about 45 minutes
●	Temperature Uniformity: ±0.5℃
●	Temperature Display Precision: ±0.1 ℃
●	Pressure Fluctuation Uniformity: ±0.1 KG
●	Average Humidity Distribution: ±3% RH

1, Highly Accelerated Stress Test(HAST) HAST test is a damp heat bias test and has another name “unsaturated pressure cooker test”. Applying test conditions of high temperature no less than 100 degrees Celsius and high pressure no less than 1 hPa, HAST is very effective accelerated test to evaluate the device for its moisture resistance within short period of time. Test condition of 120 degrees Celsius, 85%RH (1.7 hPa), under rated voltage at power supply, for 200-400 hours is generally applied to test semiconductor devices.
 
2, Pressure Cooker Test (PCT) PCT is similar to HAST test in testing moisture resistance applying test conditions of high temperature no less than 100 degrees Celsius and high pressure no less than 1 hPa. Difference from HSAT is that humidity condition in PCT is no less than 100%RH and there is no voltage bias during the test. While HAST is called unsaturated pressure cooker test, PCT sometimes called “saturated pressure cooker storage test”. This test method is suitable to evaluate resin sealed device for its thermal resistance in reflow, and crack in resin caused by heat application during the reflow can be detected within short period of time. 121 degrees Celsius, 100%RH (2hPa) for 48-96 hours are general test conditions.
 
3, Damp Heat Biased Test (THB) THB is an accelerated test to verify the resin-sealed device for its moisture resistance. Failure induced by moisture such as corrosion, contamination on surface or deterioration in contact can be detected in THB. Test condition of 85 degrees Celsius, 85%RH, under rated voltage at power supply, for 1000 hours (JESD22-A101, etc), is generally applied to test semiconductor devices.

● Imported high temperature resistant sealing solenoid valve with double-loop structure ensures no leakage of pressure. ● Wewon Pressure cooker tester equipped with the overpressure protection, overtemperature protection, one-key pressure relief, manual pressure relief multiple security devices, to ensure the maximum use and safety of users. ● Backpressure lock device. When there is pressure inside the test room, the test box door cannot be opened. ● The pressure cooker tester has misoperation Safety Device: In case the inner door is not closed tightly, the pressure cooker tester cannot start. ● Overpressure Safety Protection: When the pressure in the pot exceeds the maximum working value, the pressure will be automatically discharged and released. ● Overtemperature Protection: When the temperature in the pot is too high, the pressure cooker test equipment will alarm and automatically cut off the heating power. ● Anti-scald Protection: 85/85 humidity test duration, Specially made materials can prevent operators from contact with scald.

Safety Protection:

Currently, Most solar materials and modules can withstand long-term DHB(temperature, humidity and bias) tests without failure. In order to improve the test efficiency and shorten the test time, The pressure cooker test method was adopted. There are two main types of pressure cooker test: PCT and HAST.	[Pressure Cooker Test] and [Highly-Accelerated Temperature and Humidity Stress Test]:
If there are defects in solar packaging materials and modules that can be identified through inclusion trials, Reduce 1% degradation, can reduce 10% of the LCOE [Levelized Cost of Electricity] (actual energy output, electricity generation cost per kilowatt-hour).
The purpose of PCT test is to improve environmental stress (temperature and humidity). Used to evaluate the sealing effect of the module and the hygroscopic condition of the back plate.
Used to evaluate the integrity of non-air-tight encapsulating devices against water vapor in condensation or saturated water vapor environment. The sample is under high pressure in a condensed, high humidity environment. To allow water vapor to enter the package, exposing the weaknesses in the package. Such as layered and metallized corrosion.	PCT [Pressure Cooker Test]/ JESD22-A102 Test Specifications and Conditions:
This test is used to evaluate the updating of materials and designs in new packaging structures or packages. It should be noted that there may be some internal or external failure mechanisms in this test that are inconsistent with the actual application. Because the absorbed water vapor lowers the glassy transition temperature of most polymer materials, When the temperature is higher than the glass transition temperature, There may be an unreal failure mode.
Test Term: 121℃/100%R.H./ 80h(COVEME) 200h[toyalSolar] The Pressure Cooker Tester Application: PET EVA MODULE
Usually named pressure cooker cooking test or saturated steam test, The most important thing is to test the product under severe temperature, saturated humidity (100%R.H.) [saturated steam] and pressure. Test the high humidity resistance of the test agent, For solar packaging materials or modules,	PCT [Pressure Cooker Test] / The Test Method and Definition:
If the encapsulation is not good enough, moisture will infiltrate into the encapsulation along the interface between the rubber body or the rubber body and the wire frame. Common installation reasons: popcorn effect, break caused by metal wire corrosion, short circuit caused by contamination between packing body pins. And so on. Unlike the accelerated aging of the inclusion.
85℃/85%/1000H (JESD22-A101) →110 ℃/85%/ 264H (JESD22-A110、A118) Test Standard: JEDEC22-A110(Biased Test) JEDEC22-A118(Unbiased Test) Test Term: 110℃/85%R.H./264h The Pressure Cooker Tester Application: PET EVA MODULE

●	Adopt Taiwan color touch PLC to control humidity and steam temperature (PT-100 platinum temperature sensor).	Control System:
●	Use the pointer to display the pressure gauge.
●	The microcomputer P.I.D automatically calculates and controls the temperature and humidity of the saturated steam.
●	Manual water inlet valve (automatic water supply function, continuous test without stop).
●	Round inner bucket, stainless steel circular test inner box structure, in accordance with industrial safety container standards, can prevent water condensation design during the test.	Mechanical Structure:
●	Stainless steel bucket liner design to avoid direct impact of latent heat of steam.
●	Precision design, good air tightness, less water consumption, each time adding water can run for 400 hours continuously.
●	The patented packing design makes the door and box more closely combined, which is completely different from the traditional extrusion type and can extend the packing life.
●	The critical point LIMIT mode is automatically protected for safety, abnormal causes and failure indicator light display.

Description of the relationship between environmental stress and failure: According to the Hughes airlines report, In terms of the proportion of environmental stress causing the failure of electronic products, height accounts for 2%, salt fog accounts for 4%, sand dust accounts for 6%, vibration accounts for 28%, and temperature and humidity account for as much as 60%. So the effect of electronics on temperature and humidity is particularly significant.

Because the traditional high temperature and high humidity test (such as: 40 ℃ / 90% R.H. and 85 ℃ / 85% R.H., 60 ℃ / 95% R.H.) required for a long time, In order to accelerate the moisture absorption rate of materials and shorten the test time, Inclusion test facilities (high acceleration life tester, PCT[pressure cooker]) are available for inclusion testing. This named (degradation failure period, loss period) test.

θ10℃ Test: Estimate the product life, usually use the θ10℃ test rules, In simple terms, can be expressed as [10 ℃ rules], When the ambient temperature up to 10 ℃, the product life span would be halved; When the ambient temperature to be 20 ℃, product life will be reduced to a quarter. This rule shows how temperature affects product life (failure). On the contrary, when the product reliability test is conducted, the failure phenomenon can also be accelerated by raising the ambient temperature, and various accelerated life aging tests can be carried out.

Causes of failure caused by moisture: Depolymerization of water vapor infiltration, polymer materials, polymer combining ability, corrosion, hollow, wire solder joint release, leakage between lead and glued laminated wafer and chip off, welding plate corrosion, metal, or short circuit between the lead.

Influence of water vapor on reliability of electronic packaging: Corrosion failure, lamination and cracking, change the properties of plastic seal materials.

Failure Mode of PCT on PCB: Blister, Crack, SR de-lamination.

Semiconductor PCT Testing: PCT is mainly used to test the moisture resistance of semiconductor packaging. The products to be tested were placed in strict temperature, humidity and pressure environment. If the semiconductor package is not good enough, moisture will infiltrate into the package along the interface between the rubber body or the rubber body and the wire frame. Common reasons for improper installation: Popcorn effect, The short circuit caused by the corrosion in the dynamic metallization zone and the contamination between the leads of the package body.

Failure Phenomenon of Plastic-sealed Semiconductor due to Moisture Corrosion: Because aluminum and aluminum are cheap and easy to process, So it is usually used as the metal wire of the integrated circuit. Starting from the molding process of integrated circuit, The water vapor will then infiltrate through the epoxy resin causing corrosion of the aluminum wire leading to the opening of the road. Become the quality management most headache problem.

Although various efforts have been made to improve product quality through various improvements, including the use of different epoxy resin materials, the improvement of plastic sealing technology and the improvement of inactive plastic sealing films, But with the rapid miniaturization of semiconductor electronic devices, Corrosion of aluminum wire in plastic sealing is still a very important technical problem in electronic industry.

Explanation of Popcorn Effect: Refers to the IC encapsulated by the plastic outer body, Because the silver paste used in the wafer installation absorbs water, Once the plastic has been sealed without precaution, When the downstream assembly welding encounters high temperature, The water will cause the sealing body to burst due to evaporation pressure.

It also makes a sound like popcorn, hence its name, The phenomenon occurs when the water vapor content is higher than 0.17%. Recently, P-BGA packaging components are very popular. Not only will the silver glue absorb water, but also the substrate of the mounting plate will absorb water. Popcorn is also a frequent occurrence when management is poor.

	Testing Methods for MIL-STD-202 Test Standard Electronic & Electrical Component Parts
	HAST (Highly Accelerated Stress Test)｜HAST Relative Humidity Concepts｜ESPEC CORP

Used to evaluate the reliability of devices in moist environment, That is, apply severe temperature, humidity and increase water vapor pressure through external protective materials (encapsulated or sealed materials) or along the interface of external protective materials and metal conductors.	JESD22-A118 [Accelerated Moisture Resistance-Unbiased] Test Method Definition (HAST Unbiased Test):
Its failure mechanism and the high wet steady state of high temperature 85 ℃ / RH 85% humidity life test (JESD22 – A101 – B) are the same, No bias pressure was applied to ensure that the failure mechanism was not covered by bias pressure. The test was used to determine the failure mechanism in the encapsulation body. The sample was in non-coagulative humidity environment.
Just the temperature goes up a little bit, Its failure mechanism and the bias of high wet steady state of high temperature 85 ℃ / 85% RH humidity life test is the same, It is important to note that since the absorbed water vapor will reduce the glass transition temperature of most polymer materials, When the temperature is higher than the glass transition temperature, there may be an unreal failure mode.
An experimental method of highly accelerated moisture tolerance with temperature and humidity as the main environmental parameters. The HAST Test and the PCT [Pressure Cooker Test] are different. The inclusion Test is called the unsaturated Test, and PCT is the saturated humidity Test.	HAST [Highly-Accelerated Temperature and Humidity Stress Test] Test Method:
With general evaluation test method during the biggest difference is that it is in the area of above 100 ℃ temperature and humidity, And it’s in a high density water vapor environment. .
The purpose of inclusion is to accelerate moisture penetration testing of samples for moisture tolerance assessment by taking advantage of the fact that the water vapor pressure in the test chamber is much higher than the water vapor pressure inside the sample
The condition of damp heat test is 85 ℃ / 85% R.H. time: 1000 hours. To determine the module’s ability to resist long-term moisture penetration, Through hot and humid test can find flaws: CELL layer, EVA (delaminating, color change, bubble, atomization, Browning), string line black and TCO corrosion, spot corrosion, Thin – film yellow discoloration, junction box degumming loss.. , etc.	Damp Heat Test: IEC61215-10-13
But 1,000 hours is not enough, according to the test results from the relevant Solar plant. It takes at least 3, 000 to 5, 000 hours for the module to be found to have problems.