Blind hole processing method for multilayer printed board

Abstract

The invention relates to the technical field of circuit board manufacturing, and discloses a blind hole processing method of a multi-layer printed board. The blind hole processing method comprises thefollowing steps: S1, processing process edge; S2, windowing of PP sheet; S3, hollowing out the PP sheet; S4, pressing in the early stage; S5, first back drilling; S6, pressing all chips; S7, second back drilling; and S8, obtaining the finished product. The setting of notches and windows in the steps S1 and S2 of the processing method can ensure that the first copper foil on the upper surface of the Nth layer core board at the notches is exposed and the pressing feet of the drilling machine can be pressed on the first copper foil of the Nth core plate after pressing of the core plate. Therefore, when the drill bit contacts the first copper foil on the upper surface of the Nth layer core plate, the press feet of the drilling machine and the drilling bit form a circuit to generate current and the drill bit stops drilling. Compared with the method of pressing the presser feet of the drilling machine on the first copper foil on the upper surface of the first layer core plate, the drillingdepth can be accurately controlled to ensure that the first copper foil on the upper surface of the Nth layer core plate is just drilled without drilling through the copper foil, thus ensuring the accuracy of the drilling depth and greatly improving the success rate of processing.

Description

technical field [0001] The invention relates to the technical field of circuit board manufacturing, in particular to a blind hole processing method of a multilayer printed board. Background technique [0002] Processing multi-layer interconnected printed boards with blind holes is one of the common printed board designs. At present, most of them are used in aerospace, military industry, and medical treatment. Some blind holes are used to insert component probes, such as figure 1 , the bottom of the probe needs to be attached to the printed board pad, that is, it needs to be attached to the copper surface leaking from the bottom of the hole, such as figure 1 . Using the traditional process, the depth of the processed blind hole is not accurate, and after processing, there will be an adhesive layer in the hole that cannot be processed, and the leakage of the pad in the hole cannot be realized, so that the probe of the component cannot be used normally when inserted into the b...

AI Technical Summary

Problems solved by technology

Using the traditional process, the depth of the processed blind hole is not accurate, and after processing, there will be an adhesive layer in the hole that cannot be processed, and the leakage of the pad in the hole cannot be realized, so that the probe of the component cannot be used normally when inserted into the blind hole. Therefore, the traditional process method cannot process the part of the blind hole used to insert the component probe. The industry basically communicates with the designer and re-modifies the wiring design to meet the needs of installing the component probe. However, this method has the following disadvantages: Due to graphics limitations, when the printed board has many graphics and is too complex to be processed, it is necessary to modify the wiring design of the printed board. By increasing the number of layers of the printed board, the complex and dense design can be decomposed to meet the functional requirements of use. Increasing the number of layers of the board will increase the manufacturing cost of the printed board, and because the design thickness of the printed board is related to the use environment and area size of the finished product, the increase in thickness will make the finished printed board unusable or inconvenient to use in the use area situation, resulting in the scrapping of the finished printed board

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