Thermal Shock Test Chamber and Rapid Temperture Change Test Chamber’s Different
Thermal Shock Test Chamber and Rapid Temperture Change Test Chamber’s Different:
|
Item |
Thermal Shock Test |
Rapid Temperture Change Test
|
Remarks |
|---|---|---|---|
| Test Objectives | After a certain number of sudden changes in temperature, the test samples are tested for chemical changes or physical damage caused by thermal expansion and shrinkage |
Use and environmental stress that underlie the electronic product research and development, design, production process, because of the bad components, manufacturing process and other reasons caused by the early failure happened early exposed, modification and replacement
|
The purpose of the experiment is different |
|
Testing Phase
|
Mainly in the development and design stage, the pilot stage
|
It is mainly in mass production | Phase difference |
|
Test Object
|
Mainly used for testing material structure or composite materials. The most used now is the components of electronics or components (such as PCBA, IC). | It is mainly applicable to the components, components and equipment of electronic products | Thermal Shock Chamber are rarely used for device level |
| Temperature Change Rate Requirements |
There is no temperature change rate indicator, but the temperature recovery time is required. The reference point is generally in the outlet, and the domestic and international standards require less than 5min, the faster the better;There are also standard requirements on product surface measurements, temperature recovery time within 15min
|
In order to strengthen the screening effect, common rapid temperature change box well advised to choose a temperature change rate is 10 ~ 25 ℃ / min, and the temperature controlled variable speed rate; | |
| Sample Failure Mode |
The failure of material creep and fatigue damage is also known as brittle failure
|
Failure due to material fatigue | The failure mode is different |
| Common Fault Phenomenon | Such as the deformation or rupture of the parts, the failure of the insulating protective layer, the tightening of the moving parts or the changes of the electrical and electronic components, the rapid condensation or frost causing the electrical or mechanical failure |
If the coating, material or line head of various micro cracks expand;Make sticky joints loose;To loosen bolts or riveted joints;The failure of deformation and stress caused by different thermal expansion coefficient of materials causes the insulation of solid sealing material to decline.Loose fitting joints with insufficient mechanical tension;To increase or cause open the contact resistance of the brazing contact resistance;Malfunction of moving parts and seals
|
There are some similarities between the two |
| Reference Standard | JESD22-A106B
GJB-150-A MIL-STD-810G MIL-STD-202G |
JEDEC JESD22-A104-b
IEC68-2-1 MIL-STD-2164-85 IEC60749-25 |
|
| Equipment Selection | A. For small and medium size products of components (capacitance, inductance, IC) and plate CARDS, the optimal choice of basket type cold and heat shock is more stringent
B. For oversized products, such as LCD TV or heavy products, it is recommended that you choose three boxes to be more suitable C. If there is a heavy product, and the size is larger, it also requires too small to be used as a reference for the cold and hot impact box of horizontal basket D.Defrost cycle requirements
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A. Size of equipment, common dimensions 400L, 800L, 1000L or custom
B.Actual test temperature range (such as: - 40 ℃ ~ 85 ℃), at the same time also require equipment the whole temperature range (such as: - 70 ℃ ~ 190 ℃) C. temperature change rate requirement;Is the linear temperature change rate or average temperature change rate;If there is a requirement for the temperature change rate, be sure to carry the load, including the static load (usually aluminum ingot) and heat load (the product is hot with electric charge).
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