The Causes of PCB Warping and Prevention Methods
PCB warping is often caused by improper substrate storage and production practices. Understanding these issues is crucial for preventing warping.
Storage
Improper storage of copper-clad laminates, especially in terms of moisture absorption, is a significant cause of warping. Single-sided laminates are more prone to moisture absorption, particularly in high humidity environments, leading to increased warping. In contrast, double-sided laminates absorb moisture mainly through their edges, resulting in slower warpage.
- Ensure low humidity levels in storage areas for copper-clad laminates without moisture-proof packaging.
- Store exposed laminates to minimize moisture exposure and avoid warping.
- Avoid improper stacking, such as vertical placement or placing heavy objects on top, as it can contribute to laminate warping.
Production Practices
When dealing with PCB rigid boards, it is essential to consider the overall board’s anti-interference capability. Conventional methods include:
- Using actual soldered products for testing to ensure proper soldering.
- Avoiding long-term high-temperature soldering to prevent color changes in multi-layer boards.
- Understanding that dark-colored boards absorb more heat, leading to slightly higher measured temperatures.
Testing Temperature Curves
For a 16-layer rigid PCB, testing the temperature curve efficiently is crucial. Understanding the specific methods and steps involved is essential for accurate testing.
