Process flow of multi-layer circuit board PCB

- Jul 28, 2016-

1. The purpose of blackening and browning

1 Remove surface oil, impurities and other contaminants;


2 increasing the specific surface of the copper foil, thereby increasing the contact area with the resin, which is beneficial to the resin to fully diffuse and form a large bonding force;


3 changing the non-polar copper surface to the surface with polar CuO and Cu2O, increasing the polar bond between the copper foil and the resin;


4 The oxidized surface is not affected by moisture at high temperatures, reducing the chance of delamination of the copper foil and the resin.


5 The board prepared by the inner layer must be blackened or browned before lamination. It oxidizes the copper surface of the inner layer of the board. Generally, Cu2O is red and CuO is black. Therefore, Cu2O in the oxide layer is mainly called browning, and CuO is mainly blackening.


1. Lamination is the process of bonding the layers of the layers into a unitary body by means of a B-stage prepreg. This bonding is achieved by interdiffusion, infiltration, and intertwining of macromolecules on the interface. The step of prepreg bonding the layers of the line into a unitary process. This bonding is achieved by interdiffusion, infiltration, and intertwining of macromolecules on the interface.


2. Purpose: The discrete multilayer board and the bonded sheet are pressed together into a desired number of layers and thickness of the multilayer board.


1 typesetting copper foil, bonded sheet (pre-cured sheet), inner layer board, stainless steel, insulation board, kraft paper, outer steel sheet and other materials are laminated according to the process requirements. If more than six layers of board still need pre-typesetting. The copper foil, the adhesive sheet (prepreg), the inner layer board, the stainless steel, the separator board, the kraft paper, the outer layer steel sheet and the like are laminated according to the process requirements. If more than six layers of board still need pre-typesetting.


2 The lamination process feeds the stacked circuit boards into a vacuum hot press. The resin in the resin sheet is melted by the heat energy supplied from the machine to bond the substrate and fill the void.


3 Lamination For designers, the first thing to consider when laminating is symmetry. Because the board is subject to pressure and temperature during the lamination process, there will be stress in the board after lamination is completed. Therefore, if the laminated boards are not uniform on both sides, the stress on the two sides will be different, causing the board to bend to one side, which greatly affects the performance of the PCB. Keyou Circuit specializes in the production of high-precision multi-layer circuit boards. The products are widely used in: LCD liquid crystal modules, communication equipment, instrumentation, industrial power, digital, medical electronics, industrial control equipment, LED modules/modules, electric energy, transportation, Science and technology research and development, automotive, aerospace and other high-tech fields. Hotline: Miss Zhong


In addition, even in the same plane, if the copper distribution is uneven, the resin flow speed will be different at each point, so the thickness of the place where the copper is less will be slightly thinner, and the thickness of the copper will be slightly thicker. some. In order to avoid these problems, the factors such as the uniformity of the copper cloth, the symmetry of the laminate, the design and arrangement of the blind buried holes, etc. must be detailed in the design.


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