Micro blind hole drill with large taper outer diameter at front end

Abstract

The invention discloses a micro blind hole drill with a large taper outer diameter at a front end. The micro blind hole drill comprises a drill body and a cylindrical drill head which is fixedly arranged at one end of the drill body, a head portion is formed at one end of the drill head away from the drill body, and the diameter of drill head close to the head portion is identical to the outer diameter of a portion between the head portion of the drill head and the drill body; one end face of the head portion away from the drill body is a tip portion, the head is conical, and the outer diameter of one end of the head portion away from the drill body is small; a cutting edge is arranged on the tip portion, the lateral surface of the head portion is connected to one end of the cutting edge, and the other end is connected to an axis of the drill head; and a spiral groove is further arranged on the drill head and starts from the cutting edge and stops on the drill head between the head portion and the drill body. The blind hole drill can reduce cutting resistance and abrasion of the drill head, improve the fineness of the hole wall, a glue slag removing step is not needed after laser hole forming, and the production efficiency is improved.

Description

technical field [0001] The invention relates to a micro-blind hole drill with a front end outer diameter and a large taper. Background technique [0002] At present, printed circuit boards are developing in the direction of "dense, thin, and multi-layer", and "dense" is the leading and core of development. Reducing the number of through holes on the board is one of the effective ways to increase the circuit density of the printed board, which can greatly increase the density of wiring. However, the use of ordinary blind hole drilling needles for blind hole processing often leads to the problem of no copper in the hole or incomplete copper sinking in the copper plating process, which cannot meet the requirements in terms of production efficiency and quality, so many manufacturers choose laser drilling. Laser drilling does have certain advantages in drilling efficiency and flexibility, but laser drilling also has some defects that are prone to occur, such as copper window de...

AI Technical Summary

Problems solved by technology

However, the use of ordinary blind hole drilling needles for blind hole processing often leads to the problem of no copper in the hole or incomplete copper sinking in the copper plating process, which cannot meet the requirements in terms of production efficiency and quality, so many manufacturers choose laser drilling

Laser drilling does have certain advantages in drilling efficiency and flexibility, but laser drilling also has some defects that are prone to occur, such as copper window delamination, glass fiber protrusion, resin residue, bottom copper peeling and other defects; at the same time Laser drilling has high requirements on the thickness uniformity of the plate medium layer, and the thermal processing (CO2 infrared laser) in laser processing cannot process thicker copper layers; while cold processing (UV ultraviolet laser), because the diameter of the light spot is usually only 15 Micron, if the diameter of the hole to be drilled is large (such as 0.4mm), the drilling efficiency will become very low; more importantly, laser drilling generally requires subsequent micro-etching treatment to remove glue residue, so there will be more a process

[0003] The diameter of the ordinary drill bit is an inverted cone-shaped cylinder, that is, the diameter of the head of the drill bit is the largest, and the diameter becomes smaller as it goes up, so that the drill bit is always kept close to the head to contact the processing surface, reducing drilling. The contact area between the outer diameter of the needle and the hole wall reduces the frictional heat during processing and improves the smoothness of the hole wall. However, the processing of the entire hole is completed by the head of the drill, so the cutting amount of the head will be very large. Large, the contact part is very hot, which aggravates the wear of the tool, and also causes problems such as burning and melting of the inner layer of the plate

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