A method for laminating the covering film of the outer layer of the soft board

Abstract

The invention discloses a cover film laminating method with a flexible plate at an outer layer. The method is characterized by, before a cover film is pasted to the flexible plate in a conventional process, pre-pasting pure glue to fill a flexible circuit; after pasting of the pure glue and the cover film is finished, laminating a release film and a silicone pad on the flexible plate in sequence; and then, carrying out laminating and shaping through a laminating device. The cover film laminating method with the flexible plate at the outer layer adopts the mode of pre-pasting the pure glue and then, laminating the cover film, so that the flexible circuit is allowed to be filled by enough glue, and laminating difficulty is reduced greatly; and meanwhile, during laminating, only auxiliary silicone pad lamination is needed, thereby effectively simplifying the steps of PE film and aluminum sheet protection and the like, and greatly improving laminating efficiency.

Description

technical field [0001] The invention relates to the technical field of manufacturing a rigid-flexible printed circuit board, in particular to a method for laminating a covering film on the outer layer of a flexible board. Background technique [0002] In the design of rigid-flex board processing, there is a special structure in which the flexible board is located on the outer layer. For this type of structure, the circuit in the flexible area is etched twice and the covering film needs to be pressed twice. The first time is on the flexible board. When making the inner layer of the board: Etch one side of the flexible board as the inner layer, and then press the cover film to protect the flexible area of ​​the inner layer; Layer flex zone 2nd lamination cover film protection. This type of outer cover film lamination (such as figure 1 , figure 2 As shown), the release film, milled aluminum sheet, release film, PE film, aluminum sheet and silica gel pad are stacked in seque...

AI Technical Summary

Problems solved by technology

According to the lamination method of the above-mentioned traditional outer cover film, there are mainly the following deficiencies in the outer lamination of the cover film: 1. The surface copper thickness of the outer flexible board is generally more than 35um after electroplating, and the cover film with an ordinary glue thickness of 25um is used for lamination. The line filling effect is poor, and air bubbles are easy to appear between the lines after pressing; 2. The cover film with a high glue thickness of 50um is used for lamination, and the line filling effect is improved, but the edge of the pad is seriously overflowing, which affects the appearance of the pad. and welding quality; 3. In order to equalize the pressure and reduce air bubbles, the industry usually uses release film plus PE film and other fillers to assist in pressing, but if there are device holes above 1.0mm in the board, the release film will be removed under high pressure. The breakage of the film will cause the PE film to enter the hole, causing a great quality risk; 4. For the board with the device hole above 1.0mm, in order to prevent the PE film from entering the hole, it is necessary to rivet the aluminum sheet for protection, and mill the slot in the flexible area window, this method is cumbersome to operate, inefficient, and cannot meet the needs of mass production

Images