Method for machining semimetal blind hole with aspect ratio greater than 1

Abstract

The invention relates to a method for machining a semimetal blind hole with an aspect ratio greater than 1, which comprises the following steps: drilling a blind groove, namely, selecting a proper board and drilling a blind hole in the surface of the board, wherein the hole depth is greater than the hole diameter; drilling a flow guide hole, namely forming a reserved area and a cutting area on thetwo sides of the blind hole by taking the diameter of the blind hole as a division line and drilling a through hole in the hole bottom on one side of the cutting area, wherein the through hole does not cross the division line of the two areas; electroless plating copper and electroplating, namely, carrying out electroless plating copper and electroplating on the whole board, and forming uniform electroplated layers on the surface of the board and on the inner wall of the blind groove; carrying out milling and cutting, namely, transferring the board to a milling machine tool, milling and cutting the board by taking the division line delimited in S2 as a cutting line, and removing the cutting area; and completing machining, namely, completing the machining of the semimetal blind hole aftertrimming and post-processing. The problem that a bonding pad or cap copper cannot be manufactured in the semimetal blind hole due to falling of resin in the hole is avoided.

Description

technical field [0001] The invention relates to the field of semi-metal blind hole processing, in particular to a semi-metal blind hole processing method with an aspect ratio greater than 1. Background technique [0002] PCB (Printed Circuit Board), the Chinese name is printed circuit board, also known as printed circuit board. In order to meet certain functional requirements, it is necessary to make metallized blind holes on the PCB. At present, due to the restriction of electroplating ability, the metallized blind holes with an aspect ratio greater than 1 can only be made by back drilling and resin plugging. The general process is as follows: cutting → inner layer circuit → pressing → drilling through hole (manufacturing For back drilling)→Immersion Copper→Board Electricity→Plating Hole Pattern on Outer Layer→Back Drilling→Resin Plug Hole→Abrasive Belt Grinding Plate→Outer Layer Drilling→Normal Post-process. However, if the diameter of the back-drilled hole is too large ...

AI Technical Summary

Problems solved by technology

However, if the diameter of the back-drilled hole is too large and the thickness of the dielectric layer is relatively thin, after the resin plugs the hole, some back-drilled holes will have poor bonding force between the resin in the hole and the hole wall, causing the resin in the hole to fall off, resulting in failure. Make pads or cap copper on back drilled holes (metallized blind holes), causing production boards to be scrapped

Images