CN1889811A

CN1889811A - Technology for auxiliary removing hole wall copper in deep drilling hole

Info

Publication number: CN1889811A
Application number: CN 200610028732
Authority: CN
Inventors: 马夕松
Original assignee: HUSHI ELECTRONICS CO Ltd
Current assignee: HUSHI ELECTRONICS CO Ltd
Priority date: 2006-07-07
Filing date: 2006-07-07
Publication date: 2007-01-03
Anticipated expiration: 2026-07-07
Also published as: CN100531518C

Abstract

A technique assisting to remove off copper on hole wall in deep-drilled hole carries out deep hole drilling on PCB being finalized with pattern electric plating and antietching layer then carries out basic etching on PCB being deep hole drilled and finally removes off antietching layer of electric plating.

Description

The auxiliary hole wall process for copper of removing in a kind of deep drilling

Technical field

The invention belongs to printed circuit board (PCB) (PCB) manufacturing technology field, relate to a kind of auxiliary process of deep drilling, specifically is the auxiliary technology of removing hole wall copper in the deep drilling.

Background technology

So-called PCB deep drilling, promptly the mode by machine drilling is drilled to a perforation 2 in the hole of being made up of a part of perforation 2 and a part of not perforation 1, the degree of depth of perforation 1 is not controlled between certain two adjacent inner layer usually, and depth accuracy requires to be controlled at ± and 5mil (mil) is (as shown in Figure 1, wherein: L1 ... which layer Ln represents).The main purpose of deep drilling is that copper in the metallized hole is removed one section with the mode of boring.

In the boring procedure, when the diameter of perforation 1 not is mutually far short of what is expected with the diameter of perforation 2, existing present technology is: at first PCB is carried out graphic plating, promptly earlier PCB is carried out twice copper facing and graphic plating resistant layer 5 (as Fig. 2, shown in Figure 3), carry out alkali etching (as shown in Figure 4) then, again resistant layer 5 is removed behind the alkali etching, carried out deep drilling (as shown in Figure 5) by drill point 7 again, finish boring (as shown in Figure 6).

Generally speaking, not during the axis disalignment of the axis of perforation 1 and perforation 2, when drill point 7 carries out deep drilling, can't thoroughly bore copper 3 (as Fig. 8, shown in Figure 9) except that hole wall, if but the diameter that can control drill point 7 within the specific limits, still can bore the not copper 3 of the hole wall of perforation 1.Under a lot of situations, the diameter of perforation 1 is not restricted, mainly be subject to the distance 8 of hole wall to nearest circuit, be Drill to metal (D2M) value, drill point 7 diameters are subjected to the not restriction (as shown in Figure 7) of perforation 1 diameter when promptly boring not perforation 1, and D2M must guarantee certain distance, otherwise under the situation that perforation boring accuracy is not high, be offset at layer and layer, get on the circuit 9 when very easily causing boring not perforation 1, cause function effect PCB.

Summary of the invention

The technical problem to be solved in the present invention is: provide a kind of when perforation 1 diameter and perforation 2 diameters do not differ very little, as the perforation of 6mil≤not 1 and the diameter of perforation 2 poor＜during 8mil, can reduce the deep drilling system to aiming at the requirement of accuracy, the auxiliary technology of removing the copper of hole wall in deep drilling.

Technical scheme of the present invention is as follows:

The auxiliary hole wall process for copper of removing in a kind of deep drilling: the PCB that finishes after graphic plating and the resistant layer is carried out deep drilling, then the PCB behind the deep drilling is carried out alkali etching, remove the resistant layer of electroplating at last;

Further, PCB carries out in graphic plating and the resistant layer process, and perforation one side is not reserved the orifice ring diameter of boring less than perforation one side opening ring diameter;

Further, the hole depth of perforation not when PCB is carried out deep drilling, the depth as shallow of perforation not when carrying out in the deep drilling technology deep drilling after finishing than alkali etching again.

When PCB is carried out deep drilling, perforation 1 diameter and perforation 2 diameters do not differ when not being very big, as the perforation of 6mil≤not 1 and the diameter of perforation 2 poor＜8mil, use the present invention can reduce the deep drilling system to aiming at the requirement of accuracy, the precision of contraposition can be relaxed ± 1mil at least during boring, and can effectively remove the not remaining copper 3 of perforation 2 hole walls, reduce residual copper because of perforation hole wall not the PCB function effect.When perforation 1 not than perforation 2 diameters poor 〉=during 8mil, the present invention also equally also can use.

The present invention has following advantage: when effectively preventing in twice boring perforation and the perforation axis not overlapping not the residual copper of perforation hole wall can not bore the shortcoming of removing fully, can effectively remove after the boring the not residual copper of perforation hole wall, avoid of the influence of the residual copper of hole wall the PCB function signal.

Description of drawings:

Fig. 1 is a perforation and perforation generalized section not behind the PCB deep drilling

Fig. 2 was for plating the hole generalized section of a copper

Fig. 3 is the hole generalized section of having plated twice bronze medal and having had resistant layer

Fig. 4 is the hole generalized section after alkali etching and the place to go resistant layer

Fig. 5 carries out the deep drilling generalized section in the hole after for alkali etching and place to go resistant layer

Fig. 6 is perforation behind the deep drilling and perforation generalized section not

Fig. 7 for perforation hole wall not to nearest circuit apart from schematic diagram

Fig. 8 was for plating twice bronze medal and having the hole generalized section of just carrying out deep drilling (perforation and not perforation journal offset) in resistant layer hole

Fig. 9 was for having plated twice bronze medal and having had the hole generalized section of just carrying out deep drilling (perforation with not perforation axes intersect) in resistant layer hole

Figure 10 is the not perforation after deep drilling and the etching, utilizes alkali etching to remove the hole generalized section of copper residual in the hole

1-is perforation 2-perforation not

3-copper 5-resistant layer

6-orifice ring 7-drill point

The 8-hole wall to circuit apart from the 9-circuit

Embodiment

The invention will be further described below in conjunction with accompanying

drawing

2,3,8,9,10 and embodiment.

The auxiliary hole wall process for copper of removing in the deep drilling, when not perforation 1 diameter and perforation 2 diameters differ when not being very big, as the perforation of 6mil≤not 1 and the diameter of perforation 2 poor＜8mil, at first PCB is carried out graphic plating, after promptly PCB having been carried out twice copper facing, the graphic plating resistant layer 5 again, and position---the orifice ring 6 of holing when reserving deep drilling; As Fig. 2, shown in Figure 3, wherein orifice ring 6 diameters of perforation 1 one sides are not little than orifice ring 6 diameters of perforation 2 one sides; Shown in Fig. 8,9, guarantee that according to this drill point 7 boring procedures can remove the copper 3 that need remove hole wall by more effective brill, then the PCB after the graphic plating resistant layer is carried out deep drilling, at last, as shown in figure 10, PCB behind the deep drilling is carried out alkali etching, further remove hole wall and behind deep drilling, do not bore the residual copper 3 that removes, at last resistant layer 5 is removed.

Wherein, when perforation 2 and not perforation 1 parallel axes or perforation 2 and not perforation 1 axes intersect, the present invention all can effectively remove the residual copper 3 of boring back hole wall, thereby, greatly reduce the deep drilling system to aiming at the requirement of accuracy, the precision of contraposition can be relaxed ± 1mil at least when making boring.

In addition, owing to will carry out before the alkali etching after being advanced to graphic plating after finishing by alkali etching the opportunity of deep drilling and finishing, because of alkali etching can act on the hole wall remaining copper 3 that does not get in the perforation 1 not, so the drilling depth of perforation is not shallow when carrying out deep drilling in the deep drilling technology after the degree of depth of perforation 1 boring is not finished than alkali etching again.

Claims

1, the auxiliary hole wall process for copper of removing in a kind of deep drilling is characterized in that: the PCB that finishes after graphic plating and the resistant layer is carried out deep drilling, then the PCB behind the deep drilling is carried out alkali etching, remove the resistant layer of electroplating at last.

2, the auxiliary hole wall process for copper of removing in a kind of deep drilling according to claim 1, it is characterized in that: PCB carries out in graphic plating and the resistant layer process, and perforation one side is not reserved the orifice ring diameter of boring less than perforation one side opening ring diameter.

3, the auxiliary hole wall process for copper of removing in a kind of deep drilling according to claim 1 and 2, it is characterized in that: the hole depth of perforation not when PCB is carried out deep drilling, the depth as shallow of perforation not when carrying out in the deep drilling technology deep drilling after finishing than alkali etching again.