Method for manufacturing soft and hard combined board

Abstract

The invention relates to a method for manufacturing a soft and hard combined board. The method comprises the following steps of: preparing the circuit of an inner-layer soft board; pre-cutting a gap on the surface of each inner-layer PP (Propene Polymer) film; adhering and pressing the inner-layer PP films onto the two sides of the inner-layer soft board; pre-cutting a gap on the surface of each FR-4 layer, pressing the FR-4 layers onto the inner-layer PP films through the pseudo-adhering and transferring processes; combining the inner-layer soft board and the FR-4 layers together through pressing, and then sequentially carrying out target hole punching, hole drilling, board copper depositing and electroplating processes; preparing the circuit of a secondary outer layer, combining the secondary outer layer with the FR-4 layers; pre-cutting a gap on the surface of each of PP films on the surfaces of the secondary outer layer, combining the PP films of the secondary outer layer and the secondary outer layer together by pressing and then sequentially carrying out target hole punching, hole drilling, board copper depositing and electroplating processes; preparing the circuit of an outer layer, combining the outer layer and the PP films of the secondary outer layer and then performing a green oil coating process; and removing the FR-4 layers out of a soft board area and then performing the subsequent processes, wherein the gap width is 0.01-0.05mm. According to the invention, a PAD is effectively prevented from being subjected to fretting corrosion, PI (polyimide) is ensured to have no chromatic aberration, and the surface of the board is flat, thereby being beneficial to the improvement of the yield of circuit boards.

Description

technical field [0001] The invention relates to the technical field of circuit board manufacturing methods, in particular to a method for manufacturing a rigid-flex board. Background technique [0002] In order to meet the development needs of light, small, thin, short and bendable electronic products, flexible circuit boards have a design method of inner layer layout pads to conform to the development trend of electronic products. Arranging pads on the inner layer of the circuit board can reduce the assembly process, facilitate soldering, and save space. Therefore, at present, the soft-hard board also generally has a PAD on the inner layer of the circuit window, and combined with the inner layer of protective film to protect the inner layer of the window. Not affected by etching. However, due to the multi-layer board structure of the circuit board, the number of process operations in the manufacturing process is relatively large, which weakens the protective ability of the...

AI Technical Summary

Problems solved by technology

However, because the circuit board is a multi-layer board structure, the number of process operations during the manufacturing process is relatively large, which weakens the protective ability of the protective film, resulting in the PAD in the inner window opening area being easily corroded during etching.

In addition, using a protective film to protect the inner window will easily produce marks when the outer hard board is pressed, and the protected part and the unprotected part of the soft board area are prone to obvious color differences, and the part without the protective film is prone to board surface wrinkles during lamination. pleats, resulting in uneven product appearance and reduced yield

In order to overcome the shortcomings of opening the inner layer of the circuit and using a protective film to protect the inner layer of the window, the current industry also uses controlled laser energy to open the cover as an alternative method. When using this method, the laser energy depends on the depth of the cover and the energy tolerance. , board thickness tolerance, etc. will affect the consistency of the opening depth, and the difference in the consistency of the opening depth will induce the quality hidden danger of the inner copper layer being burned, resulting in damage to the circuit board

At the same time, the laser energy cover opening operation process is complicated, and the cost of laser cutting is high, which is not conducive to cost control and quality control