At present, the common temperature impact test and evaluation methods for printed circuit boards are widely used across various industries. These tests are designed to simulate real-world environmental conditions that PCBs may encounter during their operational life. Different standards define specific test parameters such as temperature ranges, cycle numbers, and dwell times based on the type of substrate and the intended application. In addition to these general guidelines, many companies develop more detailed internal standards to meet the unique requirements of their products, allowing for greater flexibility in testing conditions.
For example, when evaluating package substrates, the number of temperature cycles is often increased to 500–1000 to ensure long-term reliability and performance under extreme conditions. This approach helps identify potential weaknesses early in the design or manufacturing process, leading to improved product quality and durability.
In terms of standardized testing, several key specifications exist:
- **GJB362B-2009 (National Military Standard)**: This standard defines four test conditions (A, B, C, D) based on different substrate types. The low temperature ranges from -40°C to -65°C, while high temperatures vary between 85°C and 170°C. Each temperature is maintained for 15 minutes, with 100 cycles performed. The resistance change after the first and last high-temperature exposure should be less than 10%, and a micro-section analysis of the plated holes is required post-test.
- **QJ519A and QI832A (National Aerospace Industry Standards)**: These standards specify a low temperature of -65°C and a high temperature of 125°C, with each temperature held for 15 minutes and 100 cycles conducted. The conversion time between temperature extremes must be less than 1 minute. The interconnect resistance difference after the first and last cycle should not exceed 10% of the initial value. A microscopic inspection of the plated holes is also required.
- **IPC-TM-650 2.6.7 (IPC Standard)**: This standard outlines six test conditions (A to F), depending on the substrate type. Temperature ranges include low temperatures from 0°C to -65°C and high temperatures from 70°C to 170°C. Each condition lasts 15 minutes, with 100 cycles completed. The resistance change rate must be below 10%, and a micro-section evaluation of the plated holes is necessary.
These standards provide a structured framework for evaluating the thermal stability and reliability of printed circuit boards. By following these protocols, manufacturers can ensure that their products meet the rigorous demands of modern electronics, whether in military, aerospace, or commercial applications.
Feature
1.The tray is the container to carry the flowerpot, which is used to hold the excess water leaking out of the flowerpot after watering. Solve the geothermal damage to the flower roots, while avoiding the damage to the floor.
2. The ceramic tray is rich in color, beautiful in appearance and has certain ornamental value.
Attribute
| Size |
41cm, 36cm, 30cm, 27cm, 25cm, 22cm, customized |
|
Shape |
Round, customized |
| Colour | Red, green, blue, white, customized |
Ceramic Saucer,Drip Saucer,Flower Pot Saucer,Customized Tray
Yixing Bocai Pottery Co.,Ltd , https://www.bocaipottery.com