PCB (printed circuit board), laminating method for PCB and COF (chip on FPC (flexible printed circuit)), as well as liquid crystal display device

Abstract

The invention discloses a PCB (printed circuit board), a connecting method for the PCB and a COF (chip on FPC (flexible printed circuit)), as well as a liquid crystal display device. The connecting method comprises the following steps: A, a clearance groove / clearance grooves is / are arranged at one side or two sides of a laminating area / laminating areas of the PCB, wherein the PCB and the COF are laminated on the laminating area / laminating areas; B, a high-temperature laminating cutter bit is used for laminating the COF and the printed circuit board assembly (PCBA), so that the COF and the PCBA are connected on the laminating area / laminating areas. According to the invention, as the clearance grooves are arranged at the two sides of the laminating areas at which the PCBA and the COF are laminated, so that the two sides of the laminating area / laminating areas of the PCBA are not affected by the high temperature of the laminating cutter bit, thereby avoiding the defect that the distortion of the PCB at the two sides is accumulated on the PCB on the laminating area / laminating areas so that large displacement of golden fingers on the laminating area / laminating areas can be caused and ensuring the connection accuracy of a leading wire of the COF and the golden fingers on the PCBA.

Description

technical field [0001] The invention relates to the field of liquid crystal display devices and manufacturing, more specifically, to a printed circuit board, a method for laminating it with a flexible circuit board, and a liquid crystal display device. Background technique [0002] In today's liquid crystal display manufacturing process, it often involves the interconnection between the flexible circuit board (COF, Chip on FPC) and the printed circuit board (PCB), and the interconnection between the display electrode and the flexible circuit. In these connections, the anisotropic conductive film is widely used, placed between the parts to be connected, and then pressurized and heated to form a stable and reliable mechanical and electrical connection between the parts. [0003] figure 1 Shown is a schematic diagram of a current liquid crystal display driver printed circuit board assembly (PCBA) 100 . The printed circuit board assembly 100 is provided with a golden finger ar...

AI Technical Summary

Problems solved by technology

However, the longer the PCBA board, the greater the expansion, and the expansion and deformation accumulated on both sides will cause a large offset in the pressing area 102, and the contact between the pressing area 102 and the flexible circuit board 200 will be offset, resulting in ineffective connection.

like image 3 As shown, before lamination, the left, middle, and right of the entire flexible circuit board 200 are aligned on the golden fingers 103 of the lamination area 102 of the printed circuit board assembly 100, as shown in Figure 4 As shown, after lamination, due to the expansion of the PCBA, the overall expansion will be added to the lamination area 102 so that the gold fingers 103 in the lamination area 102 and the traces 201 on the left, middle, and upper right of the entire flexible circuit board 200 will have a relatively large gap. A large misalignment will affect the connectivity, and may even break the circuit and cause the product to fail to work normally

The current way to overcome it will be to shrink the design in advance and control the temperature of the same equipment to overcome it. However, it will be difficult to design or control the equipment, and it will take multiple experiments to obtain reasonable conditions and design values. And poor regulation will lead to the occurrence of bad products

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