The high temperature and high humidity test is a reliability testing method that simulates the usage and storage conditions of products in extreme hot and humid environments. By artificially creating high-temperature and high-humidity environmental conditions, the performance, stability, and durability of products are evaluated.

The core purpose of this test is to check whether the product can maintain normal functions in a hot and humid environment and to detect potential quality hazards in advance, such as material aging, structural deformation, and decline in electrical performance. This provides a basis for product design improvement, quality control, and reliability enhancement.

| Project Background

The high temperature and high humidity test for PCB (Printed Circuit Board) and PCBA (Printed Circuit Board Assembly, which is the finished product after soldering components on the PCB) is a core testing item designed by the electronics industry to evaluate the reliability of products in hot and humid environments. Its background is closely related to the application scenarios, failure risks, and quality control requirements of electronic devices.

| Project Overview

The high temperature and high humidity test is a reliability testing method that simulates the usage and storage conditions of products in extreme hot and humid environments. By artificially creating high-temperature and high-humidity environmental conditions, the performance, stability, and durability of products are evaluated.

The core purpose of this test is to check whether the product can maintain normal functions in a hot and humid environment and to detect potential quality hazards in advance, such as material aging, structural deformation, and decline in electrical performance. This provides a basis for product design improvement, quality control, and reliability enhancement.

In terms of test standards, the commonly used international standards are IEC and ISO, while in China, there are relevant standards such as GB/T. These standards clearly stipulate the environmental parameters, duration, sample handling, etc. of the test to ensure the scientific nature and comparability of the test results.

The test conditions are usually set according to the actual usage scenarios of the product and relevant standards. The temperature generally ranges from 40°C to 85°C, and the relative humidity ranges from 60% to 95%. The test duration varies from a few hours to several thousand hours. For example, for electronic and electrical products, the test is often carried out under the conditions of 40°C and 90%-95% relative humidity, and the duration may be 1000 hours.

The high temperature and high humidity test is applicable to a variety of products, including electronic components, electrical equipment, automotive parts, plastic and rubber products, coatings, etc. Through this test, it is possible to evaluate whether the solder joints of electronic components will experience false soldering or oxidation due to heat and humidity; check whether plastic parts will undergo dimensional changes or strength reduction due to moisture absorption; and verify whether the coatings will show phenomena such as blistering, peeling, and discoloration.

After the test, the samples will be subjected to appearance inspection, performance testing, etc., and a comparative analysis will be made with the state before the test to determine whether the product meets the relevant reliability requirements. If the product's performance indicators exceed the allowable range or there is obvious damage to the appearance during the test, it indicates that its reliability in a hot and humid environment is insufficient, and targeted improvements are needed.

| Test Objective

1. Expose defects in advance: Before mass-producing or launching a product into the market, discover problems in design (such as unreasonable line spacing design), materials (such as poor moisture resistance of the solder mask), or processes (such as poor copper plating) through tests to avoid batch failures.

2. Verify design reliability: Confirm that the product can maintain key performance (such as insulation resistance ≥10⁸Ω, no short circuits/ open circuits) even after experiencing high-temperature and high-humidity environments within the expected service life (for example, consumer electronics usually require 3 to 5 years, and industrial equipment requires more than 10 years).

3. Support product certification: Many industries (such as the automotive and medical industries) require products to pass reliability tests such as high temperature and high humidity tests as the basis for market entry certification to ensure that products meet safety and performance standards.

In summary, the background of the high temperature and high humidity test for PCB/PCBA stems from the challenges of the actual application environment, the need for targeted verification of core failure mechanisms, and the promotion of industry quality control and standardization. It is a key testing link to ensure the reliable operation of electronic equipment in hot and humid environments. 

| Testing Standards

| Service Products / Fields

Electronics and electrical field

Products in this field are relatively sensitive to the damp-heat environment, and the high temperature and high humidity test is an indispensable link. It includes various electronic components, such as resistors, capacitors, inductors, chips, etc. Through the test, it can be checked whether their performance parameters will drift, short-circuit or even fail due to damp-heat; there are also consumer electronic products such as mobile phones, computers, televisions, and household appliances such as refrigerators, air conditioners, washing machines. The test can verify whether they can be normally turned on and operated in the damp-heat environment and whether their functions are stable, to avoid problems such as screen flickering and key failure.

Automobile industry field

During driving and parking, automobiles often face high-temperature and high-humidity environments in different regions, and relevant parts need to undergo strict tests. Automobile electronic components, such as in-vehicle navigation, sensors, ECU (electronic control unit), etc. The test can evaluate their working reliability in high-temperature and high-humidity areas such as the engine compartment; automobile interior parts, such as seat fabrics, dashboard plastic parts, etc. Through the test, it can be judged whether mildew, aging, deformation, etc. will occur; in addition, automobile lamps, wiring harnesses, etc. also need to undergo high temperature and high humidity tests to ensure that their performance is not affected by damp-heat.

Materials and chemical industry field

The performance changes of various materials in the damp-heat environment are the focus of attention in this field. For plastic and rubber products, such as pipes, seals, gaskets, etc., the test can detect whether phenomena such as dimensional expansion, hardness reduction, and fracture occur due to moisture absorption; for coating and coating products, the test can observe problems such as blistering, peeling, discoloration, and powdering, and evaluate their protective performance; for metal materials and their products, the test can examine the rusting situation in high-temperature and high-humidity environments and judge their corrosion resistance.

Medical device field

The reliability of medical devices is directly related to the life safety of patients, so high temperature and high humidity tests are crucial. For medical electronic equipment, such as monitors and defibrillators, the test can ensure the accuracy of measurement data and the stability of equipment operation in a humid and hot environment; for disposable medical devices, such as infusion sets and syringes, the test can examine whether the materials will degrade due to heat and humidity, which may affect the safety of use.

Aerospace field

The environment where aerospace products are located is complex and changeable, and high temperature and high humidity tests are important means to ensure their reliability. For electronic equipment, sensors, cables, etc. on aircraft, the test can simulate the conditions in the high-altitude humid and hot environment or during ground storage to verify whether they can work normally; for aerospace materials, such as the shell materials and thermal insulation materials of spacecraft, the test can evaluate whether their physical and chemical properties are stable in a humid and hot environment.

| Project Advantages

1. Discover potential problems in advance and reduce market risks.

2. Improve product reliability and enhance market competitiveness.

3. Provide a scientific basis for product design optimization.

4. Meet industry standards and regulatory requirements to expand market access.

5. Reduce production costs and improve production efficiency.