A printed circuit board and its manufacturing method

Abstract

The invention discloses a printed circuit board and a manufacturing method thereof. The surface copper thickness L=L1+L2, the hole copper thickness H=H1+H2, wherein the copper layer L2 and the copper layer H2 are obtained by electroplating at the same time, and the copper layer L1 It can be manufactured and controlled separately from the copper layer H1. During the production process, the difference between the surface copper thickness and the hole copper thickness can be realized by controlling the thickness of the copper layer L1 and the copper layer H1, so that it can meet the thickness requirements at the same time. In addition, the present invention uses pre-plated tin-lead layer as the anti-corrosion layer (3), which can protect the surface copper layer from damage, and minimize the thickness of the electroplated surface copper to ensure the thickness uniformity of the surface copper; the present invention also uses anti-corrosion The adhesive material (4) protects the hole copper layer and can ensure that the thickness of the final hole copper layer meets the requirements.

Description

technical field [0001] The invention relates to the technical field of printed circuit boards, in particular to a printed circuit board with a high thickness-to-diameter ratio and a manufacturing method thereof. Background technique [0002] With the rapid development of electronic products, the wiring density of PCB boards continues to increase, the lines are getting thinner, and the thickness-to-diameter ratio of through holes is getting larger and larger. In the production process of high-thickness-diameter ratio and fine-line PCB boards, the production of thin-line and small-pitch PCB boards requires that the surface copper thickness be limited to a certain thickness. The thinner the surface copper thickness, the easier it is to make fine lines; the copper layer If the thickness is too high, it will be difficult to make fine lines; but as the interlayer connection and welding position of the line, the through hole has strict requirements on the thickness of the copper in...

AI Technical Summary

Problems solved by technology

However, in the production process of high thickness-to-diameter ratio and fine circuit PCB boards, when the electroplating meets the thickness of hole copper, the surface copper will also reach a larger thickness; thus, etching difficulties will occur in the production of fine circuits, due to surface copper There is a contradiction between the thickness requirements and the hole copper thickness requirements, and other methods must be used for production

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