PTH plating method of printed circuit boards

Abstract

A plating through hole (PTH) plating method of a printed circuit board is provided to minimize the thickness of plating by removing a copper layer formed on both surfaces of a substrate through an etching process after processing the size of a hole with 10 um-20 um. A hole is processed on one side of a printed circuit board in which a copper layer, a polyimide (PI) layer, and a copper layer are successively laminated by radiating ultraviolet ray (UV) laser (S10). The copper layer is removed by performing an etching process on the printed circuit board (S20). A plating preprocessing process is performed in the inner side of a hole and on the upper and lower sides of the PI layer (S30). A copper plating processing is performed in the inner side of the hole and on the upper and lower sides of the printed circuit board (S40). Therefore, fine patterns can be favorably formed.

Description

technical field [0001] The present invention relates to the PTH (plated through hole) gold-plating method (The PTH platingmethod of printed circuit boards) of printed circuit boards, especially after processing the hole of the substrate into 10-20um, utilize PHT filling (PHT FILL) gold-plating method to process, Thereby hole cracking can be achieved and gold plating thickness can be reduced, forming a PTH gold plating method for printed circuit boards with fine patterns. Background technique [0002] Now, with the rapid development of semiconductors and the increase of high-profile smartphones, the integration of the configuration has become higher, and the thickness of the smartphone has become thinner and requires flexibility. Therefore, the production technology of flexible circuit boards has been greatly developed. [0003] figure 1 It is a process flow chart of a flexible printed circuit board manufacturing method in the prior art. [0004] like figure 1 As shown, th...

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Problems solved by technology

[0005] However, the above method is difficult to ensure the reliability of the inner wall of the PTH, and defects such as hole cracking occur. Therefore, although the PTH can be processed by machining or using a laser, the mechanical drilling method requires the size of the hole to be large. When processing with a laser, the larger the size of the space, the longer the processing time, which increases the cost and reduces the productivity.

[0006] As mentioned above, when the size of the hole is large, it is difficult to perform RTR, and in order to prevent the occurrence of hole cracking, the size of the pad needs to be increased. Difficulties

[0007] The current PTH fill gold plating method is not a general process, but requires additional processes, and requires specialized equipment and chemicals. Therefore, the cost is high, and the workability is lower than other gold plating methods, thereby reducing productivity.

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