Printed circuit board (PCB) layer-by-layer para-position laser drilling method

Abstract

The invention relates to a printed circuit board (PCB) layer-by-layer para-position laser drilling method. The PCB layer-by-layer para-position laser drilling method comprises the following steps: manufacturing a target on the opposite second layer of circuit board; removing a copper layer covered on the target or removing a copper layer and a resin layer covered on the target, exposing the target and performing para-position; and directing drilling a blind hole by using laser. Owing to the PCB layer-by-layer para-position laser drilling method, the problem of hole misregistration of the blind hole on the inner layer can be effectively solved.

Description

[0001] technical field [0002] The invention relates to a manufacturing method of a printed circuit board, in particular to a method for layer-by-layer aligning laser drilling of blind holes in a PCB. Background technique [0003] At present, the production of printed circuit boards is developing in the direction of high precision and density. Due to the influence of circuit design, the design of PAD (pad) at the bottom of blind holes tends to be smaller. At the same time, due to the influence of offset between board layers, traditional X-RAY drilling targets are used. (Twice outer layers of graphics are superimposed), which is easy to cause blind holes to collapse. Taking a 4-layer circuit board as an example, [0004] (1) When the designed alignment target pattern (L02 / L03) has no offset, such as Figure 1a As shown, the blind hole (L0102 / L0403) has no or small offset to the inner PAD, where L02 / L03 refers to the design of the alignment target pattern on the L02 circuit b...

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Problems solved by technology

[0005] (2) Due to the low inter-layer alignment of the alignment target pattern superposition, when the designed target pattern (L02 / L03) is offset, such as Figure 1b As shown, due to the small design of the inner PAD, the blind hole (L0102 / L0403) deviates from the inner PAD or even collapses (that is, the blind hole deviates from the bottom PAD)

[0006] and by Figure 1b It can be seen that in the process of PCB production, the increase in the number of presses will increase the difficulty of the alignment accuracy of the bottom PAD pattern corresponding to the blind hole. The difficulty of the position accuracy of the bottom PAD, which leads to the increase of the position deviation of the blind hole

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