The copper-clad plate is pasted with a copper foil on the insulating material, and then baked to dry. The copper foil will shrink during the drying process, and stress in all directions will be generated, which is the source of the stress. Secondly, the purpose of baking the plate before drilling, In fact, it is mainly dehumidification. The purpose of baking the board before drilling the PCB is to remove the moisture in the board and reduce the internal stress; there is also a printed solder mask after the lamination, including characters, etc. It needs to be baked. There is also a process of baking the platen before shipping and packaging. It is also to remove moisture, and the warpage of the baked board has been greatly improved.
The aforementioned baking can eliminate theThe internal stress of the PCB board, that is, stabilizes the size of the PCB. Its significant advantage is that it can dry the moisture in the pad after baking, strengthen the welding effect, reduce virtual welding, repair rate, etc. However, baking will make The color of the PCB board changes, which affects the appearance.
usually bake in general100-120 degrees Celsius, bake for about 2H. If it is exposed to the air, it needs to be used up on the same day, otherwise oxidation will easily occur. The following baking instructions are for your reference:
1. If the PCB is sealed and unpacked for more than 5 days within 2 months of the manufacturing date, please bake at 120 ± 5 degrees Celsius for 1 hour;
2. If the PCB exceeds the manufacturing date by 2 months, please bake it at 120 ± 5 degrees Celsius for 1 hour before going online;
3. If the PCB exceeds the manufacturing date by 2 to 6 months, please bake at 120 ± 5 degrees Celsius for 2 hours before going online;
4. If the PCB exceeds the manufacturing date by 6 months to 1 year, please bake at 120 ± 5 degrees Celsius for 4 hours before going online;
5. The baked PCB must be used up within 5 days (put into IR REFLOW), and after use, it needs to be baked for another 1 hour before it can be used online;
6. If the PCB exceeds the manufacturing date for 1 year, please bake it at 120 ± 5 degrees Celsius for 4 hours before going online, and then send it to the PCB factory for re-spraying before it can be used online.