JPH037452B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for punching laminates such as printed circuit boards.

(Prior Art) FIG. 1 shows a cross-sectional view of the structure of a conventionally used punching die. In the figure, 1 is a press mechanism;
The hydraulic holder 2 includes a holder pad 3 that can be moved up and down by hydraulic pressure. Note that 4 is a pipe that supplies oil under pressure, and 5 is filled with oil. Further, a punch holder 7 is attached to the lower part of the hydraulic holder 2 via a holder 6, and a plurality of rod-shaped punches 9 are provided on the lower surface of the punch holder 7 to protrude depending on punching locations. Next, a stripper 10 having a guide hole 10a that fits the punch 9 is provided below the punch holder 7, and the stripper 10 is moved by a rod 8 slidably provided through the holder 6 and punch holder 7. , is adapted to receive pressure from a holder pad 3 driven by hydraulic pressure. The tip of the punch 9 is normally located below the surface of the stripper 10, and when the stripper 10 relatively retreats (raises) against hydraulic pressure during punching, the punch 9 protrudes. On the other hand, below the stripper 10, a die plate 12 and a die holder 13 are provided on a bolster 14 for supporting a laminate 11 made of a plate material 11A such as a printed circuit board and a metal foil 11a. Note that 12a is a die hole for punching, and 13a is a hole for discharging punched waste.

In the punching operation, the slide ram 1 is lowered by a press mechanism (not shown) while the stripper 10 is pressed downward by applying hydraulic pressure from the pipe 4, and the stripper 10 and the die plate 12 are pressed down. When the laminated plate 11 is sandwiched between the two, and the pressing force overcomes the hydraulic pressure, the stripper 10 is relatively retreated, and the tip of the punch 9 protrudes from the surface of the stripper 10 to punch out the laminated plate 11.

FIG. 2 shows the state of punching, and each reference numeral indicates the same thing as in FIG. 1. Note that 11a is a metal foil attached to the surface of the plate material. Figure 2A shows the state in which the laminate plate 11 is punched out by shear force as the punch 9 descends, B shows the state in which the punch 9 has penetrated the laminate plate 11, and C shows the state in which the punch 9 is pulled out after punching. Each shows the state in which it is removed.

(Problem to be solved by the invention) By the way, in the above-mentioned punching, the punch 9
The scraps 11b of the laminate 11 are attached to the tip of the laminate 11,
As shown in FIG. 2C, this has the drawback that it enters the punching hole again when the punch 9 is pulled out, and punching debris tends to become clogged. Therefore, as a post-punching process, high-pressure washing or needle threading and removal of punched residue are required, leading to an increase in the number of processes. In addition, as the elastic deformation of the punched hole portion of the laminate plate 11 returns, the hole shrinks after the punch 9 is pulled out, and the hole diameter (radius) becomes smaller by the amount shown by δ in FIG. 2C. It was hot. In particular, this hole shrinkage is detrimental to the densification of the printed pattern, and a large diameter punch must be used to punch holes of the desired size in anticipation of hole shrinkage, making it difficult to densify the printed pattern. This leads to an increase in the size of the land portion (a portion of metal foil provided approximately concentrically with the hole for soldering). Furthermore, the inner wall surface of the hole has many irregularities as shown in FIG. 2C, making it unsuitable for through-holes that require a uniform surface.

The present invention has been proposed in view of the above points, and its purpose is to provide a method for punching a laminated board that has a simple structure, has little hole shrinkage, and can produce a relatively smooth finish. It is in.

(Means for Solving the Problems) According to the present invention, the above object is to provide a punch 9 that moves up and down, a stripper 10 that is pressed downward and guides the up and down movement of the punch 9, and a stripper 10 that faces the stripper. , and a die plate 12 on which the laminate 11 to be punched is placed, the die plate 12
(i) the stripper 10 descends to sandwich the laminate 11 between the die plate 12; and (ii) the laminate 11 is pressed between the stripper 10 and the die plate. 12, the punch 9 protrudes downward from the surface of the stripper 10, and the laminate 11
(iii) pulling out the punch 9 upward from the punched hole with the laminate 11 sandwiched therein; (iii) moving the die plate 12 in the direction of the stripper 10 in the above state; The pressing means 16 is activated to push the laminate 11 upward, and the tip of the punch 9 is passed through the punched hole in the laminate 11 again to remove the punching residue remaining in the punched hole and to remove the inner part of the punched hole due to hole shrinkage. This is accomplished by a method for punching out a laminate, which comprises the steps of removing unevenness on a wall surface.

(Function) In the present invention configured as described above, the punch 9 is again passed through the punched hole formed by the punch 9, and the punched hole is ground.

(Example) The present invention will be described below with reference to drawings showing examples.

FIG. 3 is a configuration diagram showing one embodiment of a punching die employed in the method for punching a laminate according to the present invention, and the same parts as those shown in FIG. 1 are given the same reference numerals. In this embodiment, a die plate 12 on which a laminated plate 11 made of a plate material 11A and a metal foil 11a is placed, and a die holder 13' are connected to a spring 16.
One of the features is that it is held movably up and down by a spring unit 15 having a
The hydraulic pressure applied to the holder pad 3 is changed according to the movement (press stroke) of the slide ram 1. FIG. 4 shows the timing relationship between the press stroke S of the slide ram 1 and the hydraulic pressure P applied to the holder pad 3.
At time t ₂ after time t ₁ (bottom dead center of the press stroke) when punching is performed, the oil pressure P is rapidly reduced, and then the oil pressure P is restored before reaching the top dead center of the press stroke. be.

FIG. 5 shows the operating state corresponding to each time in FIG. 4, and FIG. 5A _{shows time t 1 ,} FIG. D shows the situation at time _t4 .

When the slide ram 1 descends with hydraulic pressure applied to the holder pad 3 and the stripper 10 pressed downward, the laminate 11 is sandwiched between the stripper 10 and the die plate 12, and the pressing force at this time causes the die plate to 12 and the spring 16 supporting the die holder 13' contract, the lower surface of the die holder 13' comes into contact with the upper surface of the spring unit 15, and when the pressing force overcomes the hydraulic pressure, the stripper 10 relatively retreats, and the punch 9 moves against the slide ram. With the press stroke of 1, the stripper 1
As shown in Fig. 5A, the laminate plate 1 protrudes from the surface of the
Punch out 1.

Next, when the slide ram 1 starts to rise,
The stripper 10 hydraulically presses the laminated plate 11, and the punch 9 is pulled out while the spring 16 remains compressed. (Fig. 5B) In this state, as in the conventional example, the punching waste 11b attached to the tip of the punch 9 enters the punching hole again, and
Hole shrinkage also occurs.

When the hydraulic pressure P applied to the holder pad 3 is suddenly removed in this state, the laminate 11 is pushed upward by the repulsive force of the spring 16, and the stripper 10 rises together with the laminate 11, causing the punch 9 to move upward. The tip passes through the punched hole of the laminated plate 11 again, pushing out the punched dregs 11b, and the hole wall surface is shaved to remove the punched dregs and the unevenness caused by hole shrinkage (FIG. 5C).

Thereafter, hydraulic pressure is gradually applied to the holder pad 3 over a certain period of time, and the stripper 1 is
0 is relatively lowered to shake off the laminated plate 11 (FIG. 5 D) stuck to the punch 9. In the above explanation, the pressing force of the stripper 10 was limited to the one using hydraulic pressure from the hydraulic holder 2, holder pad 3, etc., but it is also possible to use other means such as air pressure, and the point is that the pressing force It is sufficient as long as it can be controlled appropriately.

FIG. 7 shows a hole in a printed circuit board punched by the laminate board punching method of the present invention, and FIG. 6 shows a conventional printed circuit board for comparison. In FIGS. 6 and 7, A shows a top view, and B shows a sectional view, respectively.

That is, in the past, punching was performed with just one stroke, which caused hole shrinkage as shown in Figure 6. Therefore, in order to obtain the required hole diameter d, a larger punch was used in anticipation of hole shrinkage δ. Therefore, the land outer shape D had to be made large. On the other hand, if the land spacing l is too narrow, a defect called solder bridging occurs in which the solder applied to each land 11a rubs together, so there is a limit to the land spacing l. Therefore, in order to obtain the required hole diameter d and land spacing l, there naturally arises a limit to the pattern density, which hinders the increase in pattern density.

On the other hand, according to the present invention, the punched hole is again pierced with a punch and the shaving process is performed, so the punch diameter and the hole diameter almost match, and the hole shrinkage is reduced, resulting in the outside of the land as shown in Figure 7. There is no need to make the diameter D' unnecessarily large, and a high density pattern can therefore be achieved.

FIG. 8 shows another embodiment of the punching die employed in the method of punching a laminate according to the present invention, in which a push-up pin 17 is provided on the lower surface of the die holder 13' in place of the spring 16 in FIG.
The push-up pin 17 is controlled by hydraulic pressure or pneumatic pressure. Note that although only the lower mold is shown in the figure, the other structure is the same as that shown in FIG. 3.

FIG. 9 shows still another embodiment of the punching die employed in the method for punching a laminate according to the present invention, in which only the die plate 12 of the lower die is held movable up and down by a spring 16. It is. Note that it is also possible to change the spring 16 and provide a lifting pin and drive it by hydraulic pressure or pneumatic pressure. The other configurations are the same as in FIG. 3.

(Effects of the Invention) As described above, in the present invention, a laminate is sandwiched between an upper die stripper and a lower die plate, and a punch is protruded from the surface of the stripper to punch out the laminate. In the process of pulling out the punch, the pressing force of the stripper is loosened, the die plate is pushed up, and the punch 9 that has been pulled out is passed through the punching hole again. At the same time, it is possible to remove unevenness on the inner wall surface due to hole shrinkage of the punched hole, thereby simplifying the post-process, and having the effect that punching with a clean finish can be performed with less influence from hole shrinkage.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the configuration of a punching die used in the conventional method for punching laminates, Fig. 2 is an explanatory diagram of the operation of Fig. 1, and Fig. 3 is a sectional view showing the configuration of a punching die used in the conventional method for punching laminates. A cross-sectional view showing the configuration of an embodiment of the punching die to be adopted, FIG. 4 is an explanatory diagram showing the press stroke in FIG. 3 and the timing of oil pressure application, and FIG. 5 shows the punching operation in FIG. 3. Explanatory drawings, Figures 6 and 7
The figure is an explanatory diagram showing the finished state when the printed pattern is punched out, and Figures 8 and 9 are configuration diagrams showing other embodiments of the punching die employed in the method of punching out a laminate according to the present invention. be. 1... Slide ram, 2... Hydraulic holder, 3...
...Holder pad, 4...Pipe, 5...Oil,
6... Holder, 7... Punch holder, 8... Rod, 9... Punch, 10... Stripper, 11...
... Laminate plate, 12 ... Die plate, 13' ... Die holder, 14 ... Bolster, 15 ... Spring unit, 16 ... Spring, 17 ... Push-up pin.

Claims (1)

[Scope of Claims] 1. A punch 9 that moves up and down, a stripper 10 that is pressed downward and guides the up and down movement of the punch 9, and a die plate 1 facing the stripper and on which a laminate 11 to be punched is placed.
2. Using a punching device equipped with means for pressing the die plate 12 in the direction of the stripper 10, (i) the stripper 10 descends to sandwich the laminate 11 between the die plates 12; and (ii) the laminate 11 is is sandwiched between the stripper 10 and the die plate 12, the punch 9 projects downward from the surface of the stripper 10, and the laminate 11
(iii) pulling out the punch 9 upward from the punched hole with the laminate 11 sandwiched therein; (iv) moving the die plate 12 in the direction of the stripper 10 in the above state; The pressing means 16 is activated to push the laminate 11 upward, and the tip of the punch 9 is passed through the punched hole in the laminate 11 again to remove the punching residue remaining in the punched hole and to remove the inner part of the punched hole due to hole shrinkage. A method for punching a laminate, comprising: a step of removing irregularities on a wall surface;