In environmental reliability testing, "thermal shock testing" and "high and low temperature testing" are often mentioned. Many engineers who are new to the industry may mistakenly believe that they are the same thing or use them interchangeably.

In fact, there are significant differences between the two in terms of experimental purposes, methods, parameter requirements, etc. If the selection is incorrect, it will not only affect the product validation conclusion, but may even lead to reliability risks.

This article summarizes the technical points based on various international standards and clarifies their differences in one go.

One Cold and hot shock test: instantaneous damage, testing structural failure

Cold and hot shock test refers to the rapid switching of a specimen between two environments with large temperature differences, to examine its adaptability and structural reliability under severe thermal expansion and contraction. Commonly used for destructive screening or design verification of stress sensitive products such as welding structures, packaging materials, and electronic devices.

📘 Reference standards:

GB/T 2423.22-2012: Environmental testing for electrical and electronic products - Test N: Temperature variation

IEC 60068-2-14:2009: Test Na (rapid temperature change)

MIL-STD-883H Method 1010.8: Temperature Shock Test for Electronic Components

II High and low temperature tests: gradual temperature variation, examination of aging and adaptability

High and low temperature testing is a program-controlled slow rise and fall temperature test used to evaluate the fatigue aging characteristics of products under multiple thermal stress alternations. It is commonly used for reliability assessment of the entire machine, materials, and structural components.

📘 Reference standards:

GB/T 2423.1-2021: Low temperature test method (Test A);GB/T 2423.2-2021: High temperature test method (Test B)

GB/T 2423.22-2012: Temperature variation (Test N);IEC 60068-2-14: Temperature variation test (Test Nb)

III Standard comparison: Cold and hot shock vs. high and low temperature test

4 Common selection errors in actual testing

Can temperature cycling also show solder joint cracking?

Due to slow temperature changes, high and low temperature cycling cannot simulate sudden thermal stress; Stress conditions such as solder joint cracks that require instantaneous expansion and failure must be exposed through thermal shock.

Is thermal shock more suitable for various temperature tests than high and low temperature cycles?

Both have their own purposes. Cold and hot shock is used for design limit testing or pre factory screening, while high and low temperature cycling is more suitable for long-term aging evaluation. Mixing testing methods can actually lead to the problem of 'mistakenly killing' or 'mistakenly placing'.

Five Test box description: Taking the three box thermal shock test box as an example

The following is the structure and parameters of our SETH three box thermal shock test box, which is suitable for rapid stress testing under standards such as GB/T, IEC, MIL, etc.

Product SpecificationsSET-A3express-40℃～+150℃/ A4express-55℃～+150℃/A5.express-65℃～+150℃

Cold and hot shock is the verification of "fast, accurate, and ruthless" damage; high and low temperature cycling is the long-term durability screening of "slow, solid".