JP3231490B2 - Manufacturing method of punching die for printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates are those concerning the manufacturing process of punching抜用mold for use in drilling of a printed wiring board are many used for a variety of electronic devices such as television and video tape recorder.

[0002]

2. Description of the Related Art In recent years, strict requirements have been placed on printed wiring boards, such as higher density and higher precision, as electronic devices have become smaller, lighter, and multifunctional, and electronic components have been automatically inserted or surface mounted. .

[0003] Furthermore, electronic device manufacturers are aiming for complete automation of the mounting process of electronic components. However, inspection after soldering, which is one of the biggest obstacles, and improvement and rationalization of the process of repairing defective portions of solder adhesion are being pursued. Therefore, complete automation has not been realized, and various studies have been made on a method of forming a component insertion hole formed in a soldering land and a surface treatment method thereof for solving the problem.

[0004] A method for drilling holes in a printed wiring board using a conventional die for punching a printed wiring board will be described below.

FIGS. 4 to 9 show a method of forming holes in a printed wiring board using a conventional die for punching a printed wiring board.

In FIGS. 4 to 9, reference numeral 1 denotes a printed wiring board;
1a is an insulating substrate, 1b is a conductor pattern, 1c is a land for soldering, 1d is a component insertion hole, 1e is a guide hole, 1
f is a phenolic resin, 2a is an upper mold plate, 2b is a lower mold plate, 2c is a plate for holding and fixing a punch for punching, 2d is an upper mold plate, 2e is a support hole of a lower mold plate, 2f is a guide pin, 3 is a punch for punching.

[0007] A method of forming a hole using a punching die for a printed wiring board configured as described above will be described below.

First, a copper-clad laminate (not shown) in which copper foil is laminated on one side of a paper-based phenolic resin laminate serving as the insulating substrate 1a is formed on the copper foil surface by means of a screen printing method or the like. After an etching resist is formed and the exposed copper foil is etched using a solution such as cupric chloride, the etching resist is peeled off, and as shown in FIG. 4, a conductor pattern 1b and a soldering pattern are formed on the insulating substrate 1a. The printed wiring board 1 on which the land 1c is formed is obtained.

Next, the printed wiring board 1 is provided with a solder resist (not shown) serving as a solder resist and a road map (not shown) specifying the insertion or mounting position of the electronic component by screen printing or the like. Insulating substrate 1a
After being formed on the conductor pattern 1b and the land 1c, a guide hole 1e serving as a reference for punching a printed wiring board is formed as shown in FIG.

Then, after the printed wiring board 1 having the guide holes 1e formed therein is heated to a predetermined temperature, the guide pins 2 of the lower mold 2b of the mold set in a pressing device (not shown).
After the guide hole 1e is inserted into the hole f, the component insertion hole 1d and the outer shape of the printed wiring board 1 are processed by the punch 3 with the vertical movement of the upper die 2a of the mold as shown in FIG. The continuity check and surface treatment of the conductor pattern 1b are performed.

[0011]

However, in the above-mentioned conventional structure, the phenol resin 1 constituting the insulating substrate 1a is not provided.
f is softened by heating before punching, the atmosphere in the punching chamber, the generation of static electricity, or the degree of wear and contamination of the surface of the punch 3 constituting the punching die. During the descent of 2a or when the bottom dead center is reached, as shown in FIG. 7, phenolic resin 1f or shear debris adheres to the side surface of the punch 3 fixed to the plate 2c of the upper die 2a, or the upper die 2a As shown in FIG. 8, the phenolic resin 1f and the shear debris adhered to the side surface of the punch 3 are transferred or adhered to the periphery of the support hole 2e of the upper die plate 2d during the ascent or during the process of reaching the top dead center.

Most of the phenolic resin 1f and the shear debris transferred or adhered to the periphery of the support hole 2e of the upper die plate 2d are used for punching by blowing dry air, etc., which is performed for each punching stroke. The phenol resin 1f, which is removed from the mold but relatively easily adheres to the metal surface, gradually accumulates as the punching stroke of the punching die is repeated, and as shown in FIG. Land 1c to be the soldering part around hole 1d
And is left on the printed wiring board 1 after being adhered or transferred to the printed wiring board 1.

For this reason, air is blown every time the punching stroke is performed, and the surface of the upper die plate 2d and the lower die 2b of the punching die is adhered by brushing each time a certain number of punching strokes are completed. Phenolic resin 1f
Although foreign substances such as ash and shear debris are removed, it is not possible to remove all of the phenol resin 1f adhered during a certain number of punching strokes.

Further, the phenolic resin 1f adhered and remaining on the printed wiring board 1 cannot be completely removed even in a surface treatment in a finishing step of the printed wiring board 1 and the like. There has been a problem that soldering defects such as repelling solder and not attaching solder are induced.

In order to improve this problem, means for enhancing the appearance inspection of the printed wiring board 1, lowering the heating temperature before punching the printed wiring board 1, removing static electricity, and performing mechanical polishing in the finishing step. Have taken.

However, among the above-mentioned improvement means, the load on inspection personnel and man-hours is remarkable in strengthening the appearance inspection, and in the case of low temperature heating before punching of the printed wiring board 1, the dense component insertion holes 1d are required. In addition, cracks in the middle and chipping of the shear surface have occurred. In addition, in addition of mechanical polishing in the finishing process, the solder resist and road map are cut and the edge of the conductor pattern 1b is exposed, so that solder short-circuit occurs. Printed wiring board 1
And has the problem of affecting the characteristics of electronic devices.

The present invention solves the above-mentioned conventional problems by suppressing the adhesion of resin when drilling holes in a printed wiring board, streamlining the inspection process of the printed wiring board, and improving the reliability of printed wiring boards and electronic devices. Printed wiring that can be improved
An object of the present invention is to provide a method for manufacturing a die for punching a plate .

[0018]

In order to achieve the above object, a method for manufacturing a die for punching a printed wiring board according to the present invention comprises:
Multiple types of predetermined components that make up the die for printed wiring board
Among the punches having a diameter, the predetermined diameter is 0.9 mm to
For SKH wire rod only for punching punches in the range of 2.0mm
After drawing to the specified diameter, cutting and header processing
After finishing, low-speed barrel processing for 5 to 15 hours as finishing
By applying, the average surface roughness of the punch for punching
0.00034 mm or less and the maximum surface roughness is 0.0
It is characterized by finishing to be less than 02mm
It is.

[0019]

With this configuration, it is possible to make the side surface of the portion of the punch for punching the insulating substrate smooth, and by heating before punching, the resin constituting the insulating substrate is softened so that the punching is performed. Since it can be prevented from adhering to the surface on the punch side, it can be transferred or adhered to the upper plate of resin or shear debris, or it can be applied to the land that will be the soldering part around the processed hole such as the component insertion hole of the printed wiring board. Transfer or adhesion of the resin can be prevented.

[0020]

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a punch manufactured by a method of manufacturing a die for punching a printed wiring board according to an embodiment of the present invention.
4 shows a method of drilling holes using a metal mold .

1 to 3, reference numeral 11 denotes a printed wiring board; 11a, an insulating substrate; 11b, a conductor pattern;
Is a land for soldering, 11d is a component insertion hole, 11e
Is a guide hole, 12a is an upper die, 12b is a lower die, 12c is a plate for fixing a punch for punching, 12d is an upper die plate, 12e is a support hole of the upper die plate, 12f is a guide pin, and 13 is a punch. It is a punch for removal.

The operation of the method for manufacturing a punching die for a printed wiring board configured as described above and the method of drilling holes using the punching die thus manufactured will be described with reference to FIGS.

First, information such as an electric circuit diagram and electronic component positions and external dimensions is CAD-input, and a master film for forming a conductor pattern, a master film for forming a solder resist, a master film for forming a road map, and the like are manufactured.

At the same time, data for forming a die for processing the outer shape of the printed wiring board, the reference hole, the component insertion hole, etc., is output.
We also manufacture punching dies for printed wiring boards.

Prior to the production of a die for punching a printed wiring board, a punch 13 is first prepared. If the diameter of the punch 13 is less than 0.9 mm and exceeds 2.0 mm, After the SKH wire is cut to a predetermined size and subjected to a predetermined centerless polishing, the punch 13 for punching is formed by performing a predetermined barrel treatment for about 1 to 2 hours as a rough finish and about 30 to 45 minutes as a final finish. The diameter of the punch 13 is 0.9 mm or more and 2.0 mm
In the following cases, the SKH wire rod is drawn to a predetermined size, cut and subjected to a predetermined header processing, and then subjected to a predetermined low-speed barrel processing for about 5 to 15 hours as a final finish.
The finished average surface roughness and the finished maximum surface roughness of the punch 13 were 0.00034 mm, respectively .
And 0.002 mm or less.

The finished punch 13 is a plate 1
It is assembled together with members 2c and 12d to obtain a die for punching the printed wiring board 11 as shown in FIG.

Next, a means such as a screen printing method is applied to a copper foil of a copper-clad laminate (not shown) obtained by laminating a copper foil on one side of a paper base phenol resin laminate serving as an insulating substrate 11a. An etching resist is formed using the etching method, and the exposed copper foil is etched using a solution such as cupric chloride, and then the etching resist is peeled off to form an insulating substrate 11a, as shown in FIG. A conductive pattern 11b and a land 11c for soldering are formed on the substrate, and a solder resist (not shown) serving as a solder resist and a road map (not shown) for clearly indicating insertion and mounting positions of electronic components are screen-printed. The guide hole 11e which is formed on the insulating substrate 11a, the conductor pattern 11b or the land 11c by a method such as .

Next, after the printed wiring board 11 having the guide hole 11e formed therein is heated to a predetermined temperature, the printed wiring board 11 is guided by guide pins 12f of a lower mold 12b of a mold set in a pressing device (not shown). After the hole 11e is inserted and the outer shape of the printed wiring board 11, the component insertion hole 11d, and the like are processed by the vertical movement of the upper die 12a of the mold as shown in FIG. 3, the conduction check and surface treatment of the conductor pattern 11b are performed. Is performed, and the printed wiring board 11 is completed.

A method for forming a punch using a punching die manufactured by the method for manufacturing a die for printing a printed wiring board according to the present embodiment as described above, and a method for forming a punch for punching by a conventional hole forming method. Experimental results on the relationship between the surface roughness and the adhesion of the resin to the printed wiring board are shown in comparison with (Table 1).

[0031]

[Table 1]

As is apparent from Table 1, according to the hole forming method using the die for punching the printed wiring board of the present embodiment, the point of suppressing and preventing the adhesion of the resin to the printed wiring board. Excellent effect can be obtained.

As described above, according to the present embodiment, by using a punch for punching having an average finished surface roughness of 0.00034 mm or less and a maximum surface roughness of 0.002 mm or less, the pre-punching Resin adhesion to the punching punch side surface due to the softening of the resin that composes the insulating substrate due to the temperature can be suppressed, so that the resin and shear debris are transferred and adhered to the upper die plate, and the processing of the parts insertion hole of the printed wiring board Transfer and adhesion of the resin to the lands to be the soldered portions around the formed holes can be prevented.

In this embodiment, the finished average surface roughness is 0.0002 mm or less and the maximum surface roughness is 0.02 mm or less.
When a punch for punching of 015 mm or less is used, tens of thousands to one
Within the punching life range of the mold set to about 100,000 times, there is no need to replace punching punches. Can be prevented from adhering.

Further, in the step of punching the printed wiring board, it is possible to omit the brushing of the surface of the upper die plate and the lower die every time a fixed number of punching strokes are completed.

Although the printed wiring board 11 is a single-sided printed wiring board in the embodiment of the present invention, it may be a double-sided printed wiring board or a multilayer printed wiring board. Further, the insulating substrate 11a constituting the printed wiring board 11 is a paper-based phenolic resin laminate, but the insulating substrate 11a may be a laminated plate of a glass cloth or a glass nonwoven fabric epoxy resin.

[0037]

As described above, the printed wiring board of the present invention
By using a punch having a finished average surface roughness of 0.00034 mm or less and a maximum finished surface roughness of 0.0020 mm or less produced by a method for producing a punching die, the holes in the printed wiring board can be formed. Resin adhesion to printed wiring boards during processing can be suppressed, streamlining the inspection process of printed wiring boards and improving the reliability of printed wiring boards and electronic devices, and at the same time, man-hours for replacing punches for punching due to wear. reduction and to achieve the rationalization of the more striking抜工of
Can be done.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a method for forming a hole using a die for punching a printed wiring board according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a hole forming method using a die for punching a printed wiring board in the embodiment.

FIG. 3 is a cross-sectional view showing a hole forming method using a die for punching a printed wiring board in the embodiment.

FIG. 4 is a cross-sectional view showing a conventional hole processing method using a die for punching a printed wiring board.

FIG. 5 is a cross-sectional view showing a hole forming method using a punching die for the printed wiring board.

FIG. 6 is a cross-sectional view showing a hole forming method using a punching die for the printed wiring board.

FIG. 7 is a cross-sectional view showing a hole forming method using a punching die for the printed wiring board.

FIG. 8 is a cross-sectional view showing a hole forming method using a punching die for the printed wiring board.

FIG. 9 is a cross-sectional view showing a hole forming method using a punching die for the printed wiring board.

[Explanation of symbols]

 Reference Signs List 11 printed wiring board 11a insulating board 11b conductive pattern 11c land 11d component insertion hole 11e guide hole 12a upper die 12b lower die 12c plate 12d upper die plate 12e support hole 12f guide pin 13 punch for punching

Continuation of the front page (56) References JP-A-56-156768 (JP, A) JP-A-3-51923 (JP, U) JP-A-1-172425 (JP, U)

Claims (1)

(57) [Claims] 1. A die for punching a printed wiring board.
Of a plurality of types of punches having a predetermined diameter, a predetermined diameter
Is limited to punching punches in the range of 0.9mm to 2.0mm
SKH wire is drawn to a predetermined diameter, cut and
After applying header processing, finish as 5-15 hours
By applying a low-speed barrel treatment, the punch for punching
The average surface roughness is 0.00034 mm or less and the maximum
Finish so that surface roughness is 0.002mm or less
A method for producing a die for punching printed wiring boards, characterized by the following.