The reasons of substrate include unreasonable substrate selection, unreasonable substrate ratio, unreasonable matching structure, unreasonable matching of substrate processing materials, poor matching of substrate copper foil and substrate PP, and insufficient stress release (cooling) of substrate.
In terms of production technology, there are some reasons, such as too high temperature, unreasonable collocation of multi-layer PP plates, mixed materials from different suppliers, and great difference in the change rate between the selected ink and PP.
The specific reasons should be analyzed in detail, and it is necessary to confirm whether it is a substrate problem or a production process problem, so that it is possible to find a solution. In addition, it is difficult to solve the warping problem after the finished board is made by back pressure molding.