Introduction to Reliability Testing

1. Reliability testing originated in the military industry and later gradually applied to civilian industries. Common standards include GJB150, MIL-STD-810, MIL-STD-202G (mainly for components), IEC60068-2, ASTM, JEDEC, etc. Reliability testing aims to evaluate and analyze the reliability of products and provide useful information for design, production, and usage.

2. Reliability testing is conducted to evaluate and analyze product reliability. Through reliability testing, the reliability characteristics of a product under various environmental conditions during operation or storage can be determined, providing useful information for design, production, and usage. Testing also helps to fully expose issues in product design, raw materials, and processes. Through failure analysis, corrective measures can be identified. In this “discover–analyze–correct” cycle, product reliability is continuously improved. Therefore, conducting reliability testing and failure analysis is a crucial step in producing highly reliable products.

3. Environmental reliability testing is divided into three types: climatic environmental testing, mechanical environmental testing, and comprehensive environmental testing.

Climatic Environmental Testing

Climatic environmental testing applies stress to products through temperature, humidity, and air pressure. All reliability testing methods involve climatic environmental testing, making it an essential part of reliability testing. Currently, climatic environmental testing is considered a primary method for verifying and improving the quality of industrial products. The main test items include:

• High/Low Temperature Test: IEC60068-2-1, IEC60068-2-2

• Step Stress Test: IEC60068-2-1, IEC60068-2-2

• Constant Temperature and Humidity Test: IEC60068-2-3

• Temperature/Humidity Cycling Test: IEC60068-2-14/30/38

• Rapid Thermal Change Test: IEC60068-2-14/30/38

• Temperature Shock Test: GB2423, GJB150.5

• Mold Test: IEC60068-2-10

• Low Pressure Test: IEC60068-2-13/39/40/41

力学环境试验

Mechanical environmental testing applies stress to products through vibration, shock, and drop tests. It mainly includes mechanical vibration, mechanical shock, drop, collision, and constant acceleration tests. The main test items are:

• Vibration Testing:

  • Sine Vibration: GB/T 2423.10, IEC 60068-2-6, EN60068-2-6, ISO 8318, GB/T 4857.10, ISO 2247, GB/T 4857.7

  • Random Vibration: GB/T 2423.56, IEC 60068-2-64

• Drop Testing: GB/T 2423.8 “Environmental Testing for Electrical and Electronic Products – Part 2: Test Methods, Test Ed: Free Fall,” IEC60068-2-32 “Test Method for Free Fall.”

• Mechanical Shock Testing: GB/T 2423.5, GB/T 2425.6, IEC60068-2-27

• Mechanical Collision Testing: GB/T 2423.35, GB/T 2423.36

  ‍

Comprehensive Environmental Testing

Comprehensive Environmental Testing, also known as Combined Environmental Testing, simulates the simultaneous effect of two or more environmental factors on a product. Since the actual usage environment of products consists of multiple environmental factors, comprehensive environmental testing can more realistically simulate the impact of real-world conditions on the product. Although the methods and equipment for comprehensive environmental testing are relatively complex and the testing costs are higher, it is necessary to conduct such testing to more accurately evaluate a product’s environmental adaptability. Comprehensive environmental testing can include combinations such as vibration and temperature. Combined environmental tests should simulate the primary stresses and conditions of real-world usage, including electrical stress, vibration stress, temperature stress, humidity stress, and product operational cycles. Major types of comprehensive environmental testing include temperature and pressure testing, temperature and vibration testing, temperature, humidity and vibration testing, and temperature, pressure and humidity testing. Key standards for combined testing reference: GB/T2423.35, GB/T2423.36, IEC/EN60068-2-50, IEC/EN60068-2-51.

Advantages of Comprehensive Environmental Testing:

1. It can more realistically simulate usage environments, thereby increasing the authenticity and reliability of the test results.

2. Conducting comprehensive environmental testing allows ground-based simulations to replace in-flight tests, creating conditions for evaluating control system accuracy and reliability.

3. It exposes failure modes caused by the combined effect of multiple environmental factors, providing conditions for design improvements.

Comprehensive Environmental Test Systems
A comprehensive environmental test device subjects the test object to specified composite environmental conditions such as temperature and humidity while performing vibration testing, simulating real working conditions. Historically, comprehensive environmental testing was used for reliability evaluation of machines in aerospace and space industries. In recent years, with the rapid development of electronics such as semiconductors and widespread use of resin-based composite materials in the automotive industry, comprehensive environmental testing has become an indispensable step to ensure product reliability.

HALT and HASS test devices apply extreme stresses such as vibration, temperature, humidity, and other combined conditions during the early R&D stage of a product to identify design flaws and performance limits early. Vibration stress uses a cylinder-based vibration generation principle, enabling high-acceleration tests and 6-direction free random vibration. Temperature stress ranges from -100℃ to +200℃, with a temperature change rate of up to 60℃/min.

If you would like to learn more about testing or have any other questions, we welcome you to contact our team at weitest. Our professional team is dedicated to providing customized solutions and expert consultation services, and we look forward to working with you!