Component Moisture Sensitivity Level (MSL)
A one-stop service PCBA foundry, the warehouse will store a large number of components, and some key components need to implement MSL requirements. In the process of SMT production, there are many aspects that will affect the quality of electronic manufacturing. One of the more hidden reasons is that the PCB and components are damp, and the PCB board is damp. There will be permanent damage and other defects. Strict temperature and humidity control of components and PCBs is one of the issues that must be paid attention to in production.
Component humidity sensitivity level (MSL): IPC divides it into 8 levels of 1, 2, 2a, 3, 4, 5, 5a, and 6, and its humidity sensitivity level increases step by step.
The PCB MSL moisture-sensitive grade is only used as a reference for the residence time in the production process after opening, not for baking conditions and requirements.
The IC has not been launched on SMT for a period of time after unpacking or has not been unpacked but has been in stock for a long time, resulting in discoloration of the internal HIC (Humidity Indicator Card) after unpacking, and it needs to be baked before being launched on SMT. Sensitivity Level) IC baking time requirements are different
Generally, there are two types of semiconductor IC packages, graphite package (black surface, such as BGA, TSOP, etc.) and CSP (chip scale package). Graphite package is MSL 3, and CSP is MSL 1. Others can refer to IC supplier documents to determine MSL grade.
Take the MSL 3 IC as an example, if the chip thickness is 1.2mm, after unpacking and placed for more than 72 hours, the baking conditions
1. In the case of the tray, the baking temperature can generally be selected at 125C (generally, the highest baking temperature will be indicated on the tray), and it takes 9 hours;
2. In the case of reel, the baking temperature can only be selected at 40C, <=5% RH, and it takes 9 days.
BQC has its own component storage warehouse, which will be differentiated and stored according to the MSL requirements of IC. We have our own temperature and humidity sensitive warehouse to provide a safe storage environment for customers' materials.
