How to keep the high quality and high efficiency in the SMD production process
This article describes some of the details that need to be noted in the design:
1. Mark points are round or square, with a diameter of 1.0mm, which can be determined according to the SMT equipment. Mark points to the surrounding copper area should be greater than 2.0mm, Mark points are not allowed to crease, dirt and exposed copper, etc.;
2. There must be a Mark point on each of the four corners of the board or two Mark points on the opposite corner. The Mark point must be greater than 5 mm from the edge.
3. Each small board must have two Mark points;
4. According to the specific equipment and efficiency evaluation, it is not allowed to play the "X" board in the FPC board;
5. When fixing the board, use the wide adhesive tape to stick the board and the board firmly, and then check the film. If the board is not flat, press it again and re-check the film once;
6. The 0402 component pad pitch is 0. 4mm; 0603 and 0805 component pad pitch is 0.6mm; the pad is preferably processed into a square shape;
7. In order to avoid the small area of the FPC board being punched and sagged, punching from the bottom direction;
8. After the FPC board is made, it must be vacuum-packed after baking; before SMT is put on the line, it is best to pre-bake;
9. The size of the puzzle is preferably within 200mmX150mm;
10. There must be 4 SMT fixture positioning holes on the edge of the panel, the hole diameter is 2.0mm;
11. The minimum distance between the edge elements of the panel and the edge of the board is 10mm;
12. The distribution of the panels is distributed in the same direction as each small plate;
13. The small gold finger areas (ie hot-pressed end and solderable end) are pieced together to avoid tin fingers in SMT production;
14. The distance between the Chip component pads is a minimum of 0.5mm.
Engineering designers and craftsmen have estimated that they have had the experience of SMT soldering after the completion of FPC production; the problem is that as an excellent designer, it is possible to produce in SMT by knowing some special requirements about SMT process in advance. Maintain high quality and efficiency during the process. Because FPC has a very high requirement for the flatness of the board itself in the SMT process; in addition, the spacing, the MARK point setting, the size of the board, etc. all affect the quality and efficiency of the SMT, so the design engineer as an FPC manufacturer should know more about SMT. Some special requirements combined with the FPC process ability to comprehensively consider the design before the system, should not consider this loss, otherwise the endless troubles.