JPH01171709A - Method and device for perforating printed board - Google Patents

Abstract

PURPOSE:To lengthen the life of a drill and carry out a high-speed and high- quality perforation by providing a control device for relatively moving and positioning a printed board to be machined and a prepared-hole laser machining head as well as a finishing-hole drilling head to perforating positions. CONSTITUTION:After positioning a laser machining head 16 in a perforating position, as a laser light 31 is generated by means of a laser generator 14, the laser light 31 is introduced into the laser machining head 16, the course thereof is changed by means of a mirror or a prism 22, and the laser light 31 is introduced to a condensing lens 23 and condensed into a spot 32 with a proper diameter to be radiated to the initial perforating position on the printed board 11. Thereby, laser machined holes 9 of through holes as prepared holes are opened in the initial perforating positions on the previously determined whole perforating positions. Then, by setting the drill 33 of a drill machining head 17 so as to be conformed to each laser machined hole 9 on the board 11, the drill 33 is moved downward while being rotated to carry out drilling in accordance with the machined holes 9. Thereby, drill machined holes can be opened on the perforating position of the board 11.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method and apparatus for drilling holes in printed circuit boards, and is particularly suitable for drilling small diameter holes in multilayer printed circuit boards efficiently and with high quality. The present invention relates to a method for drilling a printed circuit board and a drilling apparatus for carrying out the method.

[Conventional technology]

In the conventional technology, as described in Japanese Patent Application Laid-open No. 155306/1983, in order to accurately drill small diameter holes in a printed circuit board, a laser beam is used to make a dent in the surface of the printed circuit board, and then the hole is drilled using a drill. I was supposed to do it.

An example of a combination of laser processing and other processing methods is a "punch press machine tool apparatus" disclosed in Japanese Patent Publication No. 11318/1983.

On the other hand, drilling a hole in a printed circuit board is a process, especially when drilling small diameter holes in a multilayer printed circuit board, and is not limited to the accuracy of the hole position, but also the condition of the hole as a whole, including the inner wall condition of the hole, remaining chips, etc. Good quality products are required. In order to improve these problems, conventional techniques have adopted methods of managing the lifespan of drills, such as preventing more than 1000 holes from being drilled with one drill. Even if this method is used, if the diameter of the drill becomes smaller, the life of the drill will have to be further shortened due to variations in the manufacture of the drill, resulting in an extremely low efficiency.

By the way, Figures 5 and 6 show various defects when drilling holes in a multilayer printed circuit board, and Figure 7 shows holes in a multilayer printed circuit board being drilled with a laser beam. Indicates defects during processing.

The multilayer printed circuit board as a workpiece shown in FIGS. 5 to 7 has a surface copper foil 1 laminated on the top and bottom surfaces of a synthetic resin board 3, and an inner node inside the synthetic resin board 3. It is constructed by burying copper w32.

FIG. 5 shows defects caused by inner wall roughness 5 of the drill hole 4 and defects caused by peeling 6 of the inner copper foil 2 when holes are drilled in the multilayer printed circuit board.

Further, FIG. 6 shows a defect due to the adhesion of chips N (smear) 7 of the synthetic resin plate 3 to the inner wall of the drilled hole 4 when the hole is similarly drilled using a drill.

The incidence of stiff defects is affected by processing conditions (spindle rotation speed, cutting speed, etc.), the thickness and material of the printed circuit board, and the material, shape, and wear of the drill. Now, if we focus on the wear of the drill and these defects, it is clear that as the drill wear progresses and becomes duller, the quality of the hole deteriorates.

FIG. 8 is an enlarged front view of the tip of the drill, and FIG. 9 is a bottom view of FIG. 8.

When drilling holes in printed circuit boards, if we closely observe the wear of the drill during processing, we find that with small diameter drills, the wear of the tip of the drill is particularly severe as shown in Figures 8 and 9, shortening the life of the drill. I understand. This portion of the drill that is severely worn is indicated by reference numeral 8 in FIG.

Next, in laser processing, which is widely used in the metal processing field, as shown in Fig. 7, not only is the shape of the laser-processed hole 9 unsuitable for use as a through hole in a printed circuit board, but the inner wall of the hole is There may be defects such as carbonization or carbonization.
As stated in, for example, Japanese Unexamined Patent Publication No. 155306/1983, it cannot be used as it is.

[Problem that the invention seeks to solve]

In short, among the conventional techniques, JP-A-60-15530
As described in Publication No. 6, the technology in which a laser beam is used to create a dent on the surface of a printed circuit board and then a drill is used to drill the hole has the problem of severe wear of the drill and shortened drill life. When the workpiece is a multilayer printed circuit board, defects such as roughness on the inner wall of the hole, peeling of the inner layer, and smear may occur.
There is a problem of poor hole quality and a problem of poor efficiency.

In addition, even with the technology of drilling holes in printed circuit boards using only a drill, the life of the drill is short, as mentioned above.
Moreover, there is a problem of poor quality of holes and a problem of poor formation.

Furthermore, with the technique of drilling holes in a printed circuit board using only a laser beam, there is a problem that the shape of the hole is not suitable as a through hole in a printed circuit board, and there is a problem that the inner wall of the hole becomes rough and carbonization occurs.

A first object of the present invention is to solve the problems of the prior art,
Even if the workpiece is a multilayer printed circuit board and a small diameter hole is to be drilled in it, the life of the drill can be extended, and high-speed, high-quality drilling can be performed. The object of the present invention is to provide a method, and the second aspect of the present invention is to provide a method.
The object of the present invention is to provide an apparatus for drilling holes in a printed circuit board, which enables the method described above to be carried out accurately.

[Means for solving problems]

The first purpose is to process a through hole as a pilot hole in a printed circuit board as a workpiece using a laser beam, and then perform finishing machining according to the through hole with a drill.
achieved.

The second object is to attach a laser machining head for pilot hole machining and a drill machining head having a drill for finishing machining in parallel to the head attachment member, and to attach a printed circuit board as a workpiece, Drilling is achieved by installing a control device that moves and positions the laser processing head and the drilling head relative to each other.

[Effect]

In the method of the present invention, a through-hole is made as a pilot hole using a laser beam, and then a drill is used to perform finishing machining according to the through-hole.Since the load applied to the tip of the drill, which is most likely to wear out, is small, the life of the drill is extended. Since it can be extended, the cutting speed can be increased, and the amount of cutting by the drill is reduced, fewer chips are generated, and the occurrence of defects such as hole clogging and smear due to chips can be reduced.

Therefore, according to the method of the present invention, even when the workpiece is a multilayer printed circuit board and a small diameter hole is to be drilled therein, the life of the drill can be extended.

In addition, it becomes possible to perform high-speed, high-quality hole drilling.

In the apparatus of the present invention, the laser processing head and the printed circuit board as the workpiece are first moved relative to each other, and the laser processing head and the hole drilling position of the printed circuit board are aligned.

Next, a laser beam is irradiated from the laser processing head to the position of the printed circuit board to form a through hole as a pilot hole.

After drilling through holes as pilot holes in all positions,
The control device relatively moves the drilling head and the printed circuit board to position the drilling head and the prepared hole.

After positioning the drilling head and the pilot hole, finishing is performed according to the pilot hole using a drill attached to the drilling head. By performing this drilling process on the entire prepared hole, the drilling work is completed.

Therefore, with the apparatus of the present invention, it is possible to accurately implement the method of the present invention.

〔Example〕

, Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a perspective view showing an example of an apparatus for implementing the method of the present invention, and Fig. 2 shows a printed circuit board as a workpiece, a table on which it is mounted, a laser oscillator, a laser processing head, and a drill. Layout diagram showing the relationship with the processing head, No. 8
The figure shows an example of a workpiece, a laser machined hole as a pilot hole,
FIG. 4 is a sectional view showing the relationship with a drilled hole which is a finished hole, and FIG. 4 is a flowchart showing an example of the method of the present invention.

The perforation device of the embodiment shown in FIGS. 1 and 2 includes a table 12 on which a printed circuit board 11 is mounted, a column 13, and a cross slide 18 as a head mounting member slidably mounted on the table 12. , a laser oscillator 14,
A protective guide 1 connected thereto and configured to be extendable and retractable
5, a laser processing head 16 attached to the cross slide 18 and connected to the laser oscillator 14 via the protection guide 15, and a drilling head 17 attached to the cross slide 18 in parallel with the laser processing head 16. and an NC device (not shown) as a control device.
It is equipped with

A printed circuit board 11, which is a workpiece, is fixed to a table 12 by pins 21.

The table 12 is moved and positioned in a horizontal plane in the X direction by an NC device.

The cross slide 18 is moved and positioned in a horizontal plane in the Y direction by an NC device, and the laser processing head 16 and drill processing head 17 are also moved and positioned together with this cross slide 18. be done.

The position of the laser oscillator 14 is fixed, and the laser processing head 16 is movable by expansion and contraction of the protective guide 15.

Inside the laser processing head 16, as shown in FIG. 2, a mirror or prism 22 and a condensing lens 23 are arranged. The laser beam 31 emitted from the laser oscillator 14 passes through the protection guide 15, enters the laser processing head 1 button, and enters the mirror or prism 22.
The light is reflected toward the condensing lens 23, and the condensing lens 23 condenses the light onto a spot 32 of an appropriate diameter, and the hole in the printed circuit board 11 is irradiated to the position where a through hole as a pilot hole is machined. It is supposed to be done.

The drilling head 17 includes a rotational drive source for a drill (not shown), a chuck (not shown), and a drill 33 attached thereto.

Then, at least the drill 33 rotates and moves in the Z direction perpendicular to the horizontal plane, so as to finish the printed circuit board 11 according to the prepared hole.

Next, an example of the method of the present invention will be explained with reference to FIGS. 1 to 4 in connection with the operation of the drilling apparatus of this embodiment.

In this embodiment, the printed circuit board 11 is the fourth printed circuit board 11.
As shown in the figure, the target is a multilayer printed circuit board in which surface steel foils 1 are laminated on both the upper and lower surfaces of a synthetic resin board 3, and inner layer copper foils 2 are embedded in multiple stages inside.

As shown in FIGS. 1 and 2, this printed circuit board 11 is
It is fixed on the table 12 with pins 21.

Then, in step 40 of FIG. 3, the NC data is read out by the NC device.

Then, in step 41 shown in FIG. 3, the table 12 is moved in the X direction and the cross slide 18 is moved in the Y direction by the NC device, and the laser processing head 16 is positioned at the first drilling position.

After positioning the laser processing head 16 at the drilling position,
At step 42 in FIG. 3, the laser beam 31 is oscillated by the laser oscillator 14. As shown in FIG. 2, the laser beam 31 emitted from the laser oscillator 14 passes through the protective guide 15 and is introduced into the laser processing head 16.
The course of this laser beam 31 is changed by a mirror or prism 22 within the laser processing head 16, and the path is changed by a condensing lens 22.
3, and is focused by this condensing lens 23 into a spot 32 of an appropriate diameter, and the first hole in the printed circuit board 11 is irradiated to the position. As a result, as shown in FIG. 4, a laser-machined hole 9, which is a through hole as a pilot hole, is drilled at the position where the first hole was to be drilled. In addition, this laser machined hole 9
is tapered and has inner wall roughness,
Furthermore, the accuracy of the hole diameter is poor, making it unsuitable for use as a through hole in printed circuit boards.

Steps 41 and 42 are repeated to drill laser-processed holes 9 at all predetermined positions in the printed circuit board 11.

Next, in step 43 of FIG. 3, it is determined whether the laser-processed holes 9 have been drilled at all positions. If all the laser-processed holes 9 have not been drilled, steps 41 and 42 are repeated. When all the laser-processed holes 9 have been drilled, the process advances to the next step 44.

The laser processing head 16 and the drilling head 17 are mounted in parallel on the cross slide 18 with a distance d between them, as shown in FIG. Therefore, in step 44 of FIG. 3, the NC data is corrected by the distance d, and the drilling of the printed circuit board 11 is determined based on the position, that is, the drill installed in the drilling head 17 for each laser-processed hole 9, which is a pilot hole. Set so that 33 matches.

Then, similarly to step 41, the printed circuit board 11
The hole drilling determines the position and the drill 33.

Next, in step 46 of FIG. 3, the drill 33 is rotated and moved downward in the Z direction, and a drill hole is machined according to the laser machined hole 9 as a pilot hole. As a result, drilled holes 10 shown by imaginary lines in FIG. 4 are drilled at the positions of the printed circuit board 11.

In the drill hole processing, the hole is drilled according to the laser machined hole 9 which is a through hole as a pilot hole drilled in advance.
Even if the printed circuit board to be processed is a multilayer printed circuit board as shown in Figure 4, or even if you are drilling an extremely small diameter hole, the drill that wears out the most when drilling the hole alone is the drill that wears out the most. Since the tip of 33 is not used,
Can extend the life of the drill, drill 3 when cutting
Since the load of 3 is small, cutting speed can be increased,
Since the amount of cutting is small, there is less generation of chips (it is possible to reduce defects such as hole clogging and smear caused by chips).

Steps 45 and 46 are repeated, and the holes determined in the printed circuit board 11 are drilled at all positions, that is, the same number of drilled holes 10 are drilled according to the laser-processed holes 9.

Next, in step 47 of FIG. 3, it is determined whether or not the drilled holes 10 are drilled at all the positions of the printed circuit board 11. If all the drilled holes 10 have not been drilled, steps 45 and 46 are repeated. When all the drilled holes 10 are drilled, 1
The drilling process for the printed circuit board 11 is completed.

In addition, in the present invention, as shown in the drawings, the printed circuit board 11
The structure is not limited to the configuration in which the table 12 on which is mounted is moved in the X direction, and the laser processing head 16 and the drill processing head 17 are moved in the X direction.
, a laser processing head 16 and a drill processing head 17
Any configuration may be used as long as it can be positioned by relatively moving the two in the X and X directions.

Further, in the present invention, the control device is not limited to an NC device, but may be any device having the desired functions.

〔Effect of the invention〕

According to the method of the present invention described above, a through hole is drilled as a pilot hole using a laser beam, and then finishing processing is performed according to the through hole using a drill, and the load applied to the tip of the drill, which is most likely to wear out, is small. Drilling has the effect of extending the life of the drill and increasing the cutting speed, so it has the effect of improving machining efficiency, and it also reduces the amount of cutting by the drill, reducing the generation of chips. This also has the effect of improving the quality of holes, since the occurrence of defects such as hole clogging and smear due to chips can be reduced.

Further, according to the apparatus of the present invention, a laser processing head for preparing a pilot hole and a drill processing head having a drill for finishing are attached to the head mounting member in parallel, and a printed circuit board as a workpiece, By installing a control device for relatively moving and positioning the laser processing head and the drilling head to the drilling position, there is an effect that the method of the present invention can be carried out accurately.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of an apparatus for implementing the method of the present invention, and Fig. 2 shows a printed circuit board as a workpiece, a table on which it is mounted, a laser oscillator, a laser processing head, and a drill. Layout diagram showing the relationship with the processing head, 3rd
The figure is a flowchart showing an example of the method of the present invention, FIG. 4 is a cross-sectional view showing an example of a workpiece, the relationship between a laser-machined hole as a pilot hole, and a drilled hole as a finish-machined hole, and FIG. 5 , Figure 6 is a cross-sectional view showing various defects when holes are drilled into a multilayer printed circuit board, Figure 7
The figure is a cross-sectional view showing defects when drilling holes in a multilayer printed circuit board using a laser beam, FIG. 8 is an enlarged front view of the tip of the drill, and FIG. 9 is a bottom view of the same. 9... Laser processing hole, 10... Drill processing hole, 11
... Printed circuit board as a workpiece, 12... Table on which the printed circuit board is mounted, 14... Laser oscillator, 1
5... Laser light protection guide, 16... Laser processing head, 17... Drill processing head, 18... Cross slide which is a head attachment member, 31... Laser light, 32... Laser light Spot, 33...Drill, 40-47...Steps for carrying out the method of the present invention.

Claims (1)

[Claims] 1. Drilling of a printed circuit board, which is characterized in that after drilling a through hole as a pilot hole in a printed circuit board, which is a workpiece, with a laser beam, finishing machining is performed using a drill according to the through hole. Method. 2. Attach a laser processing head for pilot hole processing and a drill processing head with a drill for finishing processing in parallel to the head mounting member, and attach the printed circuit board that is the workpiece, the laser processing head, and the drill processing head. 1. A printed circuit board drilling device, comprising a control device for moving and positioning a head relative to a drilling position.