JPH0855748A - Formation of through hole - Google Patents

Abstract

PURPOSE:To provide a method by which a through hole can be accurately formed even when the green sheet is thin. CONSTITUTION:Since a pin P is pressed against the film surface of a green sheet GS and part of the sheet GS is pushed in a hole H by utilizing the deformation of the sheet GS caused by the pin P, and then, the pushed-in part is cut off between the edge Ha of the hole H and base film BF of the sheet GS, a through hole can be formed through the sheet GS as the sheet GS remain supported by the base film BF and the sheet GS is not broken nor elongated while the sheet GS is transported or worked even when the sheet GS is thin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a through hole having a predetermined diameter in a green sheet used for manufacturing a laminated ceramic electronic component.

[0002]

2. Description of the Related Art A laminated ceramic electronic component such as a laminated inductor or a laminated coil has a ceramic chip in which conductor layers having a predetermined pattern interposed between ceramic layers are connected to each other through through holes provided in the ceramic layer. A desired conductor circuit is formed therein. The above-mentioned through holes are formed in advance on the green sheet to be the ceramic layer by using a device as shown in FIG.

This device comprises a male die M1 having pins P having a predetermined diameter in a predetermined arrangement and a female die M2 having holes H having the same diameter as the pins P in the same arrangement, and the green sheet GS is made of metal. The peripheral portion is attached to the support frame F made of
It is placed on the female mold M2 during punching.

As shown in FIG. 12, formation of a through hole by the above-described device is performed by lowering the male die M1 toward the female die M2 and shearing when the pin P of the male die M1 is inserted into the hole H of the female die M2. It is performed by punching the green sheet GS with the same diameter as the pin P and the hole H by force. The punched sheet piece C is sucked and removed to the outside through a passage D provided in the female die M2.

[0005]

By the way, there is a demand for miniaturization and multi-layering of multilayer ceramic electronic components, and the thickness of the above green sheet GS tends to become thinner and thinner. Therefore, if the green sheet GS is directly attached to the support frame F as in the conventional apparatus, the sheet is likely to be broken or stretched during the process of conveying and processing, which causes inconvenience, which makes it impossible to form a desired through hole. There is a point.

The present invention has been made in view of the above problems, and an object thereof is to provide a method capable of accurately forming a through hole even when the thickness of the green sheet is thin.

[0007]

In order to achieve the above object, the invention according to claim 1 has a template having a hole having a predetermined diameter, a pressing tool having a diameter smaller than the hole, and one surface supported by a flexible film. Prepared green sheet, press the pressing tool against the film surface with the sheet surface of the green sheet facing the hole forming surface of the template, and part of the sheet due to film deformation due to pressing It is characterized in that it is pushed in and the pushed portion is cut between the hole edge and the film.

According to a second aspect of the present invention, a template having a hole having a predetermined diameter, a pressing tool having a conical inclined surface capable of making line contact with the hole edge in the circumferential direction, and a green sheet having one surface supported by a flexible film are provided. Prepare a sheet and press the conical slope of the pressing tool against the film surface with the sheet surface of the green sheet facing the hole forming surface of the template, and part of the sheet of the template due to film deformation accompanying the pressing. It is characterized in that it is pushed into the hole and the pushed portion is cut between the hole edge and the film.

According to a third aspect of the present invention, there is provided a template having a hole having a predetermined diameter, a pressing tool having a spherical surface capable of making line contact with the hole edge in the circumferential direction, and a green sheet having one surface supported by a flexible film. Prepare a sheet, press the spherical surface of the pressing tool against the film surface with the sheet surface of the green sheet facing the hole forming surface of the template, and press the part of the sheet into the hole of the template due to the film deformation accompanying the pressing. It is characterized in that the pushed portion is cut between the hole edge and the film.

A fourth aspect of the present invention is characterized in that, in the through hole forming method according to any one of the first to third aspects, an annular protrusion is provided at the edge of the hole.

According to a fifth aspect of the present invention, a template having a hole having a predetermined diameter and an annular projecting portion at the edge of the hole, a pressing tool having a flat surface larger than the annular projecting portion, and one surface made of a flexible film are used. Prepare a supported green sheet, press the pressing tool against the film surface with the sheet surface of the green sheet facing the hole forming surface of the template, and part of the sheet through the film It is characterized in that it is pushed into the protrusion and the pushed portion is cut between the annular protrusion and the film.

According to a sixth aspect of the present invention, there is provided a template having a hole having a predetermined diameter and an annular projecting portion at the edge of the hole, a roller-shaped pressing tool larger than the annular projecting portion, and one surface supported by a flexible film. Prepared green sheet, press the pressing tool against the film surface with the sheet surface of the green sheet facing the hole forming surface of the template, and insert a part of the sheet through the film into the annular protrusion of the hole edge. It is characterized in that it is pushed in to cut the pushed portion between the annular protrusion and the film.

[0013]

According to the present invention, when the pressing tool, its conical slope or spherical surface is pressed against the film surface of the green sheet, a part of the sheet is pressed into the hole of the template by the film deformation accompanying the pressing, The indented portion is crushed between the hole edge and the film and cut in a shape that substantially matches the hole shape.

According to the fourth aspect of the present invention, when the pressing tool, its conical inclined surface or spherical surface is pressed against the film surface, the annular protruding portion provided at the edge of the hole bites into the sheet surface to accelerate the cutting action. Other functions are similar to those of the first to third inventions.

According to the fifth and sixth aspects of the present invention, when the pressing member is pressed against the film surface of the green sheet, a part of the sheet is pressed into the annular protrusion of the hole edge through the film,
The pressed portion is crushed between the annular protrusion and the film and cut so as to substantially match the shape of the hole (annular protrusion).

[0016]

EXAMPLE FIG. 1 shows a green sheet used in the present invention. The green sheet GS is a base material prepared by kneading a ceramic powder, an organic binder and the like into a ceramic slurry by using a doctor blade method or the like. It is formed by coating the film BF with a thickness of several tens of μm. The base film BF is made of a flexible film such as PET and has a thickness of several tens of μm.

In the drawing, the dimensions of the green sheet GS and the base film BF are made to match, but the dimensions of the green sheet GS may be smaller than that of the base film BF, and a strip-shaped base film BF is used. The green sheet GS may be formed in a strip shape on the BF.

FIG. 2 shows a first embodiment of the through hole forming device. This device is composed of a male die M1 having pins P having a flat diameter and a predetermined diameter in a predetermined arrangement, and a female die M2 having holes H having a diameter larger than that of the pins P in the same arrangement. Further, the female die M2 is provided with a passage D for sucking and removing the cut sheet piece to the outside.

When the through holes are formed in the green sheet GS using the above apparatus, first, as shown in FIG. 2, the film surface of the green sheet GS faces the male mold M1 and the sheet surface faces the female mold M2. Place it between the two molds. Then, as shown in FIG. 3, the male M
Both molds M1 and M2 are brought close to each other by lowering 1 and the lower end of the pin P is pressed against the film surface of the green sheet GS.

In the above-mentioned pin pressing, as shown in FIG. 4A, the pin contact portion of the base film BF is deformed downward due to its flexibility, and the film deformation causes the lower sheet portion to be punctured. It is pushed into H.

When the film is further deformed by pressing the pin P, the sheet pressing portion is crushed between the edge Ha at the upper end of the hole H and the base film BF to make a notch, and as shown in FIG. 4 (b). The green sheet GS is cut in a shape that substantially matches the shape of the hole H. The cut sheet piece C is sucked and removed to the outside through the passage D.

After the cutting is completed, the molds M1 and M2 are separated from each other, and the pressing of the film surface by the pin P is released.
As shown in, the base film BF recovers its shape by its elasticity, and the green sheet GS is formed with a through hole GSa that matches the shape of the hole H.

In this embodiment, since the through holes GSa can be formed in the green sheet GS while the green sheet GS is supported by the base film BF, even if the thickness of the green sheet GS is thin, the sheet can be conveyed and processed in the process. It is possible to form the desired through-hole GSa accurately by making the handling extremely easy without breaking or extending.

Further, since the through hole GSa can be formed without cutting scratches on the base film BF, even when the conductive paste is printed on the sheet surface and the paste is filled in the through hole GSa in a later step, the filling paste is not formed. It can be prevented from infiltrating into the base film BF or leaking to the outside, and the glue sheet GS and the conductive paste can be easily peeled from the base film BF.

FIGS. 6A and 6B show a second embodiment of the through hole forming device. This device is composed of a male mold having pins P of a predetermined diameter having a flat lower surface in a predetermined arrangement, and a female mold having holes H having a diameter larger than that of the pins P in the same arrangement. Further, a sharp annular protrusion Hb having the same inner diameter as the hole H is provided at the upper edge of the hole H.

When a through hole is formed in the green sheet GS using the above apparatus, first, the green sheet G is formed.
S is placed between the molds so that the film surface faces the male mold and the sheet surface faces the female mold. Then, the two molds are brought close to each other in the same state, and the lower end of the pin P is pressed against the film surface of the green sheet GS.

In the above pin pressing, the pin contact portion of the base film BF is deformed downward due to its flexibility,
By the deformation of the film, the lower sheet portion is pressed against the annular protrusion Hb, and the annular protrusion Hb is attached to the seat surface.
Cut into.

When the film is further deformed by pressing the pin P, the sheet pressing portion is crushed between the tip of the annular protrusion Hb and the base film BF to make a notch, and as shown in FIG. 6 (b). The green sheet GS is cut in a shape that substantially matches the shape of the annular protruding portion Hb. The cut sheet piece C is sucked and removed to the outside through the passage.

In this embodiment, by providing the annular protrusion Hb at the upper edge of the hole H, there is an advantage that the annular protrusion Hb can bite into the seat surface to promote the cutting action. Other functions and effects are similar to those of the first embodiment.

Although the pin P having a flat lower surface is used in the first and second embodiments, the lower end of the pin P may be rounded.

FIGS. 7A and 7B show a third embodiment of the through hole forming device. This device is composed of a male type having pins P in a predetermined arrangement and a female type having holes H in the same arrangement. Further, at the lower end of the pin P, a hole H
A conical slope P that can make line contact with the upper edge Ha in the circumferential direction.
a is provided.

When a through hole is formed in the green sheet GS using the above apparatus, first, the green sheet G is formed.
S is placed between the molds so that the film surface faces the male mold and the sheet surface faces the female mold. Then, the two molds are brought close to each other in the same state, and the conical slope Pa at the lower end of the pin P is pressed against the film surface of the green sheet GS.

In the above pin pressing, the pin contact portion of the base film BF is deformed downward due to its flexibility,
Due to the film deformation, the lower sheet portion is pushed into the annular protrusion Hb.

When the film is further deformed by the pressing of the pin P, the sheet pressing portion is crushed between the edge Ha at the upper end of the hole H and the base film BF to make a notch, and as shown in FIG. 7 (b). The green sheet GS is cut in a shape that substantially matches the shape of the hole H. The cut sheet piece C is sucked and removed to the outside through the passage.

In this embodiment, the conical slope Pa at the lower end of the hole H is used.
By providing the above, there is an advantage that the pressing force is concentrated on the hole edge Ha and the cutting action can be performed smoothly. Other functions and effects are similar to those of the first embodiment.

FIGS. 8A and 8B show a fourth embodiment of the through hole forming device. This device is composed of a male type having pins P in a predetermined arrangement and a female type having holes H in the same arrangement. Further, at the lower end of the pin P, a hole H
A spherical surface Pb capable of making line contact with the upper edge Ha in the circumferential direction is provided.

When forming a through hole in the green sheet GS using the above apparatus, first, the green sheet G
S is placed between the molds so that the film surface faces the male mold and the sheet surface faces the female mold. Then, the two molds are brought close to each other in the same state, and the spherical surface Pb at the lower end of the pin P is pressed against the film surface of the green sheet GS.

In the above pin pressing, the pin contact portion of the base film BF is deformed downward due to its flexibility,
Due to the film deformation, the lower sheet portion is pushed into the annular protrusion Hb.

When the film is further deformed by the pressing of the pin P, the sheet pressing portion is crushed between the edge Ha at the upper end of the hole H and the base film BF to make a notch, and as shown in FIG. 8 (b). The green sheet GS is cut in a shape that substantially matches the shape of the hole H. The cut sheet piece C is sucked and removed to the outside through the passage.

In this embodiment, the spherical surface Pb is provided at the lower end of the hole H, so that the pressing force can be concentrated on the hole edge Ha and the cutting action can be smoothly performed. Other functions and effects are similar to those of the first embodiment.

In the third and fourth embodiments, the annular projection Hb similar to that of the second embodiment is provided at the upper edge of the hole H, and the cutting action is performed by utilizing the bite of the projection Hb. Can be promoted.

FIGS. 9A and 9B show a fifth embodiment of the through hole forming device. This device is composed of a male type having pins P in a predetermined arrangement and a female type having holes H in the same arrangement. Further, at the upper edge of the hole H, as in the second embodiment, a sharp annular protrusion H having the same inner diameter as the hole H is formed.
b is provided, and a flat surface Pc larger than the annular protrusion Hb is provided at the lower end of the pin P.

When forming through holes in the green sheet GS using the above apparatus, first, the green sheet G is formed.
S is placed between the molds so that the film surface faces the male mold and the sheet surface faces the female mold. Then, the two molds are brought close to each other in the same state, and the flat surface Pc at the lower end of the pin P is pressed against the film surface of the green sheet GS.

In the above-mentioned pin pressing, the seat surface is pressed against the annular protruding portion Hb via the base film BF, and the annular protruding portion Hb bites into the seat surface.

As the pressing progresses further, the sheet pressing portion is crushed between the annular protruding portion Hb and the base film BF to make a notch, and the green sheet GS moves to the annular protruding portion Hb as shown in FIG. 9B. It is cut in a shape that almost matches the shape of. The cut sheet piece C is sucked and removed to the outside through the passage.

In the present embodiment, the annular projection Hb provided at the upper edge of the hole H bites into the sheet surface to accelerate the cutting action, and since the film is not deformed at the time of forming the through hole, it is clean. A cutting plane can be obtained. Other functions and effects are similar to those of the first embodiment.

FIGS. 10A and 10B show a sixth embodiment of the through hole forming device. In this device, the annular protrusion Hc at the upper end of the hole H is made to protrude more largely than that of the fifth embodiment, and the taper at the tip of the protrusion is formed inside.

In this embodiment, by tapering the inside of the tip of the annular protruding portion Hc and making the outer surface cylindrical, a through hole having a shape corresponding to the outer diameter of the annular protruding portion Hc can be formed without sheet compression. It can be obtained with high dimensional accuracy.
Other actions and effects are similar to those of the fifth embodiment.

The pins of the fifth and sixth embodiments described above may be plates having the same flat surface. Instead of these, a roller may be used and the roller may be moved in parallel to form a through hole. Good.

[0050]

As described above in detail, according to the first aspect of the present invention, the through holes can be formed in the green sheet while the green sheet is supported by the film.
Even if the thickness of the green sheet is thin, the sheet will not be broken or stretched during the transportation and processing process, and the handling can be made extremely easy and the desired through hole can be accurately formed.

According to the second and third aspects of the present invention, the pressing force can be concentrated on the edge of the hole to smoothly perform the cutting action. The other effects are the same as those of the invention of claim 1.

According to the fourth aspect of the present invention, the annular protrusion can bite into the seat surface to promote the cutting action. Other effects are the same as those of the inventions of claims 1 to 3.

According to the fifth and sixth aspects of the present invention, the annular projecting portion can be made to bite into the sheet surface to accelerate the cutting action, and since the film is not deformed at the time of forming the through hole, a clean cutting surface can be obtained. be able to. The other effects are the same as those of the invention of claim 1.

[Brief description of drawings]

FIG. 1 is a perspective view of a green sheet used in the present invention.

FIG. 2 is a cross-sectional view showing a first embodiment of a through hole forming device.

FIG. 3 is an operation explanatory diagram of FIG.

FIG. 4 is an operation explanatory diagram of FIG.

FIG. 5 is a diagram illustrating the operation of FIG. 2;

FIG. 6 is a cross-sectional view of essential parts showing a second embodiment of the through-hole forming apparatus.

FIG. 7 is a cross-sectional view of essential parts showing a third embodiment of the through-hole forming apparatus.

FIG. 8 is a cross-sectional view of essential parts showing a fourth embodiment of the through-hole forming apparatus.

FIG. 9 is a cross-sectional view of essential parts showing a fifth embodiment of the through-hole forming apparatus.

FIG. 10 is a cross-sectional view of essential parts showing a sixth embodiment of the through-hole forming apparatus.

FIG. 11 is a cross-sectional view showing a conventional example of a through hole forming device.

FIG. 12 is an operation explanatory diagram of FIG. 11.

[Explanation of symbols]

Gs ... Green sheet, GSa ... Through hole, BF ...
Base film, M1 ... Male type, M2 ... Female type, P ... Pin,
Pa ... conical slope, Pb ... spherical surface, Pc ... flat surface, H ...
Hole, Ha ... Edge, Hb, Hc ... Annular protrusion.

Claims (6)

[Claims] 1. A template having a hole having a predetermined diameter, a pressing tool having a diameter smaller than that of the hole, and a green sheet having one surface supported by a flexible film are prepared. A pressing tool is pressed against the film surface while facing the hole forming surface, and a part of the sheet is pressed into the hole of the template by the film deformation accompanying the pressing, and the pressed portion is cut between the hole edge and the film. A through hole forming method characterized by the above. 2. A template having a hole having a predetermined diameter, a pressing tool having a cone-shaped inclined surface capable of making line contact in the circumferential direction at the hole edge, and a green sheet having one surface supported by a flexible film are prepared. , With the sheet surface of the green sheet facing the hole forming surface of the template, press the conical slope of the pressing tool against the film surface, and press the part of the sheet into the hole of the template due to the film deformation accompanying the pressing. A method for forming a through hole, characterized in that the pressed portion is cut between the hole edge and the film. 3. A green plate having a hole having a predetermined diameter, a pressing tool having a spherical surface capable of making line contact in the circumferential direction at the hole edge, and a green sheet having one surface supported by a flexible film are prepared. Press the spherical surface of the pressing tool against the film surface with the sheet surface of the sheet facing the hole forming surface of the template, and press the part of the sheet into the hole of the template by the film deformation accompanying the pressing, and press the pressed portion. A method for forming a through hole, comprising cutting between the hole edge and the film. 4. The through-hole forming method according to claim 1, wherein an annular protrusion is provided at the edge of the hole. 5. A template having a hole of a predetermined diameter and an annular protrusion on the edge of the hole, a pressing tool having a flat surface larger than the annular protrusion, and a green sheet having one surface supported by a flexible film. With the sheet surface of the green sheet facing the hole forming surface of the template, press the pressing tool against the film surface, and push the part of the sheet into the annular protrusion of the hole edge through the film. A method of forming a through hole, characterized in that the pressed portion is cut between the annular protrusion and the film. 6. A template having a hole of a predetermined diameter and an annular protrusion on the edge of the hole, a roller-shaped pressing tool larger than the annular protrusion, and a green sheet having one surface supported by a flexible film. Prepare, press the pressing tool against the film surface with the sheet surface of the green sheet facing the hole forming surface of the template, and push a part of the sheet into the annular protrusion of the hole edge through the film A method of forming a through hole, characterized in that a portion is cut between the annular protrusion and the film.