. The board on which the components are mounted is bent after soldering, and the component feet are difficult to cut flat. The board can't be installed on the chassis or the socket in the machine. What should be done to prevent warpage of the pcb multi-layer circuit board? Let's learn about it with the editor of Victory Control.

Warpage prevention in engineering design: Matters needing attention when designing printed boards:

A. The arrangement of the interlayer prepreg should be symmetrical, for example: for a six-layer board, the thickness between 1~2 and 5~6 layers and the number of sheets of the prepreg should be the same, otherwise it will simply warp after lamination.

b. Multi-layer core board and prepreg should use the same supplier's products.

c. The area of the circuit pattern on the outer A side and the B side should be as close as possible. If the A side is a large copper surface, and the B side has a few lines, the printed board will easily warp after etching. Assuming that the line areas on the two sides are too different, some independent grids can be added to the sparse side for balance.

Anti-warping of the baking board before cutting:

The purpose of baking the board (150 degrees Celsius, time 8±2 hours) before blanking the copper clad laminate is to remove the moisture in the board, and at the same time, the resin in the board is completely cured, and the remaining stress in the board is further eliminated, so as to avoid the board warping. Helpful. Now, many double-sided and multi-layer boards still insist on the process of baking the board before or after cutting. However, there are also some board factories that make exceptions. Now the time for baking boards in various PCB factories is not the same, ranging from 4 to 10 hours. It is recommended to decide according to the level of the printed boards produced and the customer's requirements for warpage. After cutting into a jigsaw puzzle, it is still the same as the whole piece of aniseed and then unloading. Both methods are feasible. It is recommended to bake the board after cutting. The inner board should also be baked. High precision pcb circuit board