If we encounter humidity sensitive electronic components in the processing of PCBA, we must attach great importance to them. Due to improper management of humidity sensitive components, it can directly lead to poor soldering, resulting in various defects such as poor soldering, solder connection, and insufficient soldering. So what are the management methods for humidity sensitive components in PCBA processing?

The management of humidity sensitive components is mainly carried out from two aspects: storage and feeding.

Each type of humidity sensor has its own MSL (Moisture Sensitivity Level), which clearly specifies the maximum allowable exposure time and feeding interval for humidity sensors. Once the agreement is exceeded, strict baking must be carried out before going online. Humidity sensitive components are generally stored in moisture-proof cabinets with specific functions. It is recommended to install specific temperature and humidity alarms on the moisture-proof cabinet to remind warehouse personnel that if the humidity exceeds the standard, they will alarm and intervene manually. When removing, it is necessary to check the condition of the humidity label card and record the removal time and the return time of the remaining materials.

There are 8 levels of MSL classification

Level 1- less than or equal to 30 ° C/85% RH infinite workshop life

Level 2- Less than or equal to 30 ° C/60% RH, one year workshop life

Level 2a - ≤ 30 ° C/60% RH workshop life

Level 3- ≤ 30 ° C/60% RH 168 hours workshop life

Level 4- ≤ 30 ° C/60% RH 72 hours workshop life

Level 5- workshop life less than or equal to 30 ° C/60% RH for 48 hours

Level 5a - ≤ 30 ° C/60% RH 24 hour workshop life

Level 6-12 hours workshop life less than or equal to 30 ° C/60% RH (for Level 6, components must be baked before use and must return within the time limit specified on the moisture sensitive label)

The process of MSL determination is:

(1) Perform SAT on the good IC and confirm that there is no delamination phenomenon.

(2) Bake the IC to completely eliminate moisture.

(3) Humidify according to MSL level.

(4) Pass IR Reflow 3 times (simulate IC loading, repair and disassembly, repair and re loading).

(5) SAT inspection for delamination and IC testing function.

If the above test can be passed, it indicates that the IC packaging meets the MSL level.

Generally speaking, PCBA processing plants will establish strict forms that require operators to conduct strict registration before each retrieval, inspection, and feeding to ensure the effectiveness of materials. The management of humidity sensitive components is a crucial operational requirement in the entire PCBA processing process, and strict management is necessary.