Anti-cracking structure for preventing board edge cracking and manufacturing technology thereof

Abstract

The invention relates to an anti-cracking structure for preventing board edge cracking, which is characterized in that the anti-cracking structure includes a circuit board, a fixed table and hot-meltblocks; the circuit board consists of core boards and a PP sheet clamped between the core boards, each core board consists of a board body and a copper foil layer, the PP sheet is used for bonding thecore boards, and locating holes are arranged in the edge of the circuit board; a number of locating pins corresponding to the locating holes are vertically arranged on the upper surface of the fixedtable, and the locating pins are inserted into the locating holes; and the hot-melt blocks are arranged at the edges of the core boards and are used for pre-fixing the core boards, and a number of anti-cracking holes are arranged in the edges of the hot-melt blocks. The phenomenon of circuit board cracking during processing can be avoided, and the production yield can be improved.

Description

technical field [0001] The invention relates to the field of circuit processing, in particular to an explosion-proof structure and a manufacturing process for preventing board edge explosion. Background technique [0002] At present, two core and above boards in the PCB industry are generally produced by fusion, because the fusion method is relatively easy to produce layer deviation compared with riveting (copper rivets are required), and the fusion board edge (long side board edge) is generally designed with 6-8 For the fusion site, the size of each fusion site is generally designed to have a width of about 8 mm and a length of about 12 mm. The temperature during fusion is generally set at 170-190°C, and the melting time is 3-20S, which is set according to the thickness of the plate and the number of PP sheets. After the fusion position is fused at high temperature, PP and the substrate are combined together. After the fusion block of the multilayer board is solidified at ...

AI Technical Summary

Problems solved by technology

After the fusion position is fused at high temperature, PP and the substrate are combined together. After the fusion block of the multilayer board is solidified at high temperature, the pp sheet is then solidified at high temperature. During the heating process, the pp sheet melts and flows, and the flowing pp sheet is mixed with the solidified heat When the junction of the frit is solidified, it is easy to produce voids, and it is easy to explode at the fusion block in the subsequent process, which will cause the delamination of the edge of the PCB unit, especially if the surface treatment is tin plate, the fusion position of the tin plate is easy When the explosion occurs seriously, it will be led to the PCB unit near the edge of the board. Now, it is often used to mill out the exhaust groove around the hot melt to discharge the water vapor generated by the pp sheet during heating. However, the processing of the exhaust groove requires the circuit board to be rebuilt. It is fixed on the milling machine and then processed. The operation is complicated and time-consuming, and the area of ​​the exhaust groove is large. When the dry film is attached to the circuit board in the subsequent process, the dry film is easily broken, which affects the subsequent processing of the circuit board.

Images