A high-precision stepped crimping hole processing method

Abstract

The invention discloses a high-precision stepped crimping hole processing method, which comprises the following steps: Step 1, punching a positioning hole; Step 2, measuring expansion and contraction for the first time; Step 3, positioning the first pin; Step 4, passing Mechanically drill through holes; step 5, perform controlled depth drilling to obtain controlled depth drilled holes, the depth of controlled depth drilled holes is the depth of the target conduction layer, and the controlled depth drilled holes are the inner diameter of the target through hole; step 6, sink copper; Step seven, electroplating; step eight, forming electroplating PIN holes after electroplating the positioning holes, and testing the size of electroplating PIN holes; step nine, positioning through the second pin nails and electroplating PIN holes matched with electroplating PIN holes; Drill to get backdrilled drill holes. The invention reduces the influence of positioning point deviation and improves the position accuracy of back drilling; the tool diameter of back drilling only needs to be increased by 0.025mm to 0.1mm relative to depth control drilling, which avoids the large diameter of conventional back drilling. The waste of space; the allowable deviation accuracy of the finished hole position is less than the copper thickness of the hole, ensuring that the crimping hole is a through hole.

Description

Technical field: [0001] The invention belongs to the field of PCB board manufacture, in particular to a method for processing a high-precision stepped crimping hole. Background technique: [0002] With the development of 5G high-speed products, PCB is moving towards high density and high integration, especially the demand for high layer count, high wiring density and low stub (stub). The company proposes a method to increase the wiring density through stepped back drilling, through small holes and then controlled deep drilling, and then processing with a back drilling aperture equal to or slightly larger than the controlled depth drilling diameter; compared with conventional back drilling diameter Larger than through holes result in a waste of space. [0003] For example, a 0.4mm through hole is used as an example. Conventionally, a 0.4mm drill is used, and a layer of copper is plated on the hole wall by sinking copper and electroplating; in order to control the stub, it is...

AI Technical Summary

Problems solved by technology

Because the conventional back-drilling drill can cover the influence of the deviation of the drilling hole position, the main factors affected are the extremely poor thickness of the plate. After testing the section of the coupon, confirm that the stub is greater than the extreme difference of the plate thickness to ensure that there will be no risk of open circuit; but for the ladder Back drilling, in addition to extremely poor board thickness, there is also the risk of partial open circuits caused by hole deviation

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