2. Improper management of these components can lead to poor soldering, causing defects such as soldering failures, continuous solder, and insufficient solder.
3. Managing humidity-sensitive components involves two key aspects: storage and feeding.
4. Each type of humidity-sensitive component has a specific MSL (Moisture Sensitivity Level), which defines the maximum allowable exposure time and feeding interval.
1. Once the agreement is exceeded, strict baking must be performed before proceeding online. Humidity-sensitive components should be stored in a moisture-proof cabinet with specific functions. It is recommended to install a dedicated temperature and humidity alarm on the moisture-proof cabinet to alert warehouse staff if the humidity exceeds the set threshold, triggering an alarm and requiring manual intervention. When removing components, check the condition of the humidity label card and record both the removal time and the time of returning any remaining material to the box.
2. There are 8 levels of MSL (Moisture Sensitivity Level) classification:
– Level 1: ≤ 30°C/85% RH, unlimited floor life
– Level 2: ≤ 30°C/60% RH, one year floor life
– Class 2a: ≤ 30°C/60% RH, four weeks floor life
– Level 3: ≤ 30°C/60% RH, 168 hours floor life
– Level 4: ≤ 30°C/60% RH, 72 hours floor life
– Level 5: ≤ 30°C/60% RH, 48 hours floor life
– Class 5a: ≤ 30°C/60% RH, 24 hours floor life
– Level 6: ≤ 30°C/60% RH, 12 hours shop life (For Level 6, components must be baked before use and must be reflowed within the time limit specified on the moisture-sensitive attention label.)
3. The process for determining MSL is as follows:
– (1) Conduct SAT (Surface Analysis Test) on good ICs to confirm no delamination.
– (2) Bake the IC to completely remove moisture.
– (3) Humidify according to the MSL level.
– (4) Pass IR-Reflow testing 3 times (to simulate IC upload, repair and dismantling, and repair and upload).
– (5) Perform SAT to check for delamination and test the IC’s functionality.
4. If the IC passes the above tests, it indicates that the IC package meets the specified MSL level.
5. Generally, PCBA factories will implement stringent procedures, requiring operators to complete detailed registrations before each pick-and-place, inspection, and feeding to ensure material effectiveness. Managing humidity-sensitive components is a critical aspect of the PCBA processing workflow, and rigorous management practices must be enforced.
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