Managing Humidity-Sensitive Components in PCB Manufacturing
PCB EMS electronics manufacturing plants often handle humidity-sensitive electronic components with care to prevent issues like poor soldering and defects. Proper management of these components is crucial to ensure product quality.
Key Aspects of Managing Humidity-Sensitive Components:
- Storage: Components should be stored in a moisture-proof cabinet with temperature and humidity monitoring.
- Feeding: Components have specific Moisture Sensitivity Levels (MSL) that define exposure time and feeding intervals.
Moisture Sensitivity Levels (MSL) Classification:
- Level 1: Unlimited floor life at ≤ 30°C/85% RH
- Level 2: One year floor life at ≤ 30°C/60% RH
- Class 2a: Four weeks floor life at ≤ 30°C/60% RH
- Level 3: 168 hours floor life at ≤ 30°C/60% RH
- Level 4: 72 hours floor life at ≤ 30°C/60% RH
- Level 5: 48 hours floor life at ≤ 30°C/60% RH
- Class 5a: 24 hours floor life at ≤ 30°C/60% RH
- Level 6: 12 hours shop life; components must be baked before use and reflowed within specified time
MSL Determination Process:
- Conduct SAT on good ICs to confirm no delamination.
- Bake ICs to remove moisture completely.
- Humidify based on MSL level.
- Pass IR-Reflow testing 3 times.
- Perform SAT and functionality tests.
If components pass the tests, they meet the specified MSL level requirements. PCBA factories enforce strict procedures to manage humidity-sensitive components effectively, ensuring product quality and reliability.
