JP2001077505A - Through hole forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a through hole forming method, capable of easily forming a through hole having a desired shape. SOLUTION: In this through hole forming method, a green sheet 10 is sandwiched between a plate 13 on which a hole is opened and a protrusion plate 15, and a protrusion 14 of the protrusion plate 15 is pressed against a carrier film 11. The green sheet 10 is pushed into a hole 12 of the plate 13, and a part into which the green sheet 10 is pushed is exposed from the aperture part of the hole 12 of the plate 13. An adhesive film 16 is arranged on the plate 13 and pressed with a roller 17. The adhesive film 16 is peeled from the plate 13, and a sheet chip 101 as a part of the green sheet 10 is peeled from a carrier film 11. A trace, where the sheet chip 101 of the green sheet 10 is peeled off, becomes a through-hole 102.

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, and more particularly to a method for forming a through hole having a predetermined shape in a green sheet used for manufacturing a ceramic multilayer part.

[0002]

2. Description of the Related Art Ceramic multilayer components such as LC filters and high-frequency switches are formed by connecting predetermined conductor layers formed between ceramic sheet layers to each other through through holes provided in the sheet layers. A desired circuit is formed in a multilayer substrate. The through holes are formed in advance on a green sheet to be a sheet layer, and a method for forming the through holes is disclosed in, for example, JP-A-8-55748.

FIG. 2 is a sectional view of a main part showing a conventional method of forming a through hole. The green sheet 50 used in this forming method is formed by mixing a ceramic slurry prepared by kneading a ceramic powder and an organic binder and the like onto a carrier film 51 using a doctor blade method or the like.
It is formed by coating with a thickness of m. Note that the carrier film 51 is made of a plastic film such as PET and has a thickness of several tens of μm.

First, the green sheet 50 is placed between the male mold 53 and the female mold 55 such that the carrier film 51 faces the male mold 53 having the pin 52 and the green sheet 50 faces the female mold 55 having the hole 54. Deploy. (Figure 2
(A)) Next, the male mold 53 and the female mold 55 are brought close to each other by lowering the male mold 53, and the lower ends of the pins 52 of the male mold 53 are pressed against the carrier film 51. The pin 52 of this male mold 53
When the carrier film 51 is pressed, the portion of the carrier film 51 abutting on the pin 52 is deformed downward due to its plasticity.
0 is pushed into the hole 54 of the female mold 55. (Figure 2
(B)) Then, when the pins 52 of the male mold 53 are further pressed, the deformation of the carrier film 51 further proceeds, and the pressed portion of the green sheet 50 is moved between the edge 54 a at the upper end of the hole 54 of the female mold 55 and the carrier film 51. The sheet piece 56 is cut in a shape substantially conforming to the shape of the hole 54 of the female mold 55 by being crushed. (FIG. 2C) Next, the male mold 53 and the female mold 55 are separated from each other to
When the pressing of the carrier film 51 by 2 is released, the carrier film 51 returns to its shape by its own elasticity,
In the green sheet 50, a through hole 57 which is a hole that passes through the front and back of the green sheet 50 that matches the shape of the hole 54 of the female mold 55 is formed. (FIG. 2D) In the conventional through-hole forming method as described above, the through-hole 57 can be formed in the green sheet 50 while the green sheet 50 is supported by the carrier film 51. Even in the case where the thickness is small, there is an advantage that the green sheet 50 is not broken or stretched in the course of transport and processing, handling is extremely easy, and a desired through hole 57 can be formed accurately.

[0005]

However, in the above-described conventional through-hole forming method, a desired portion of the green sheet is cut by pressing a male pin against the carrier film. Since the film and the film are bonded by an intermolecular force, it is difficult to peel the green sheet from the carrier film only by pressing the male pin against the carrier film, and a through hole having a desired shape cannot be formed. There is.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a through-hole forming method capable of easily forming a through-hole having a desired shape.

[0007]

In order to solve the above-mentioned problems, a method of forming a through-hole according to the present invention comprises forming a perforated plate having a hole of a predetermined diameter and a projection having a smaller diameter than the hole of the perforated plate. A green sheet provided with a carrier film on one surface thereof is sandwiched between the projection plate and the projection plate provided so that the carrier film faces the projection plate side, and the projections of the projection plate are pressed against the carrier film to form the perforated plate. A part of the green sheet pushed into the hole is peeled off by using a peeling means having an adhesive property.

[0008] The method of forming a through hole according to the present invention comprises:
The peeling means is an adhesive film.

According to the through hole forming method of the present invention,
Since a part of the green sheet pushed into the hole of the perforated plate by the projection of the projection plate is peeled off by the peeling means, the green sheet at the position where the through hole is formed can be easily peeled from the carrier film.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part showing an embodiment according to the through hole forming method of the present invention. The green sheet 10 used in this forming method is formed by a method similar to the conventional method, and has a carrier film 11 on one surface.

First, the green sheet 10 is placed between the perforated plate 13 having the holes 12 and the projection plate 15 having the projections 14, the green sheet 10 is disposed on the perforated plate 13 having the holes 12, and the carrier film 11 is disposed on the side of the carrier film 11. It is sandwiched between the projection plates 15 having the projections 14 so as to face each other. (FIG. 1A) The diameter of the projection 14 of the projection plate 15 is smaller than the diameter of the hole 12 of the perforated plate 13.

Next, by pushing up the projection plate 15, the perforated plate 13 and the projection plate 15 are brought close to each other, and the projection 14 of the projection plate 15 is pressed against the carrier film 11. (FIG. 1B) Next, when the projections 14 of the projection plate 15 are pressed, the portions of the carrier film 11 abutting on the projections 14 are deformed upward due to their plasticity, and the green sheet on the upper side is deformed by the deformation of the carrier film 11. 10 is pushed into the holes 12 of the perforated plate 13. (FIG. 1C) Next, when the protrusions 14 of the protrusion plate 15 are further pressed, the deformation of the carrier film 11 further proceeds, and the pressed portion of the green sheet 10 is exposed from the opening of the hole 12 of the perforated plate 13. (FIG. 1D) Next, the adhesive film 16 serving as a peeling means is disposed on the side of the perforated plate 13 not facing the green sheet 10, and the adhesive film 16 is pressed by the roller 17. (FIG. 1E) Next, when the adhesive film 16 is peeled off from the perforated plate 13, the sheet piece 101 which is a part of the green sheet 10 adhered to the adhesive film 16 becomes the carrier film 1.
Stripped from 1. (FIG. 1F) Next, when the perforated plate 13 and the protruding plate 15 are separated from each other and the pressing of the carrier film 11 by the protruding portions 14 of the protruding plate 15 is released, the carrier film 11 returns to its shape by its own elasticity. The green sheet 10 has a through hole 1 that is a hole that passes through the front and back of the green sheet 10 that matches the shape of the stripped sheet piece 101.
02 is formed through. (FIG. 1 (g)) Through these series of steps, a desired through hole 102 can be formed in the green sheet 10 without making a hole in the carrier film 11.

Actually, in the through hole forming method shown in FIG. 1, the thickness of the perforated plate 13 and the height of the projections 14 of the projection plate 15 are 100 μm and 200 μm, respectively. Difference between the diameter of the projections 14, that is, the clearance is 50 to 100.
μm.

By using such a perforated plate 13 and a projection plate 15, a through hole 102 having substantially the same size as the diameter of the perforated plate 13 could be formed in the green sheet 10.

FIG. 2 is a sectional view showing a method for manufacturing a multilayer substrate. The conductive paste 20 is filled in the through holes 102 of the green sheet 10 formed by the method of FIG. 1 and dried. (FIG. 2A) Next, the wiring pattern 21 is printed on the surface of the green sheet 10 and dried. (Figure 2
(B)) Next, from the green sheet 10 to the carrier film 11
After peeling off, a plurality of green sheets 10 are laminated to form a laminate 22. (FIG. 2C) Next, the laminate 2
2 is thermocompression-bonded and fired to complete the multilayer substrate 23 having the wiring pattern 21 connected by the via-hole electrode 201 therein. (FIG. 2D) FIG. 3 is a cross-sectional view showing a method for manufacturing a multilayer substrate having a cavity. A green sheet 10 having a through hole 102 which becomes a part of the cavity formed by the method of FIG.
Is dried as it is, a carrier film (not shown) is peeled off from the green sheet 10 and laminated with a green sheet 10 ′ having no through-hole 102 to form a laminate 25. (FIG. 3A) Next, after the laminate 25 is thermocompressed and fired, a multilayer substrate 27 having a cavity 26 is completed.

Then, after laminating the laminate 25 of FIG. 3 on the laminate 22 of FIG. 2, thermocompression bonding, and firing, a cavity 26 is provided on the upper portion, and the wiring pattern 21 connected by the via-hole electrode 201 is built in. Multilayer substrate 28 (FIG. 4)
Is formed.

In the embodiment of the through hole forming method described above, a perforated plate is arranged on the upper side, and a projecting plate is arranged on the lower side, and the projecting plate is pushed up.
The case where the green sheet is pushed into the hole of the perforated plate has been described, but the protruding plate is placed above and the perforated plate is placed below, and the protruding plate is lowered to push the green sheet into the hole of the perforated plate. May be. Also in this case, the green sheet is naturally disposed on the perforated plate side and the carrier film is disposed on the protruding plate side.

Although the case where the shape of the hole of the perforated plate and the shape of the projection of the projection plate is substantially circular has been described, if the shape of the hole of the hole plate and the shape of the projection of the projection plate are formed in accordance with the shape of the through hole. For example, when the shape of the through hole is rectangular, the shape of the hole of the perforated plate and the shape of the projection of the projection plate is rectangular, and when the shape of the through hole is oval, the shape of the hole of the hole plate and the shape of the projection of the projection plate is elliptical. Becomes

Further, the case where the peeling means is an adhesive film has been described, but pressure and peeling may be performed simultaneously using a roller having an adhesive material on the surface.

[0020]

According to the first aspect of the present invention, a part of the green sheet pushed into the hole of the perforated plate by the projection of the projection plate is peeled by the peeling means having adhesiveness. The green sheet at the position where the through hole is formed can be easily separated from the carrier film. As a result, a through hole having a desired shape can be easily formed.

Further, since a part of the green sheet is peeled off by a peeling means having adhesiveness to form a through hole in the green sheet, fragments of the green sheet and a part of the carrier film are formed in the through hole. The possibility of remaining is reduced. As a result, poor filling of the conductive paste into the through-holes and, consequently, poor connection can be suppressed.

Furthermore, since the outer dimensions of the through-holes, ie, the outer dimensions of the holes of the perforated plate, are smaller than the outer dimensions of the holes of the perforated plate, the projections of the projection plate are less likely to be damaged, and the maintenance cost of the projection plate is reduced. Accordingly, the manufacturing cost of through holes can be reduced.

According to the through hole forming method of the second aspect, since the peeling means is an adhesive film, the manufacturing apparatus can be inexpensive, and the manufacturing cost of the through hole can be further reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing an embodiment according to a through-hole forming method of the present invention.

FIG. 2 is a cross-sectional view illustrating a method of manufacturing a multilayer substrate using the through-hole forming method of FIG.

FIG. 3 is a cross-sectional view illustrating a method for manufacturing another multilayer substrate using the through-hole forming method of FIG. 1;

FIG. 4 is a cross-sectional view of a multilayer substrate formed by using the through-hole forming method of FIG.

FIG. 5 is a sectional view of a main part showing a conventional method of forming a through hole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Green sheet 102 Through hole 11 Carrier film 12 Hole 13 Perforated plate 14 Projection 15 Projection plate 16 Adhesive film

Claims (2)

[Claims] A green sheet having a carrier film on one surface is provided between a perforated plate having a hole of a predetermined diameter and a projection plate having a projection smaller in diameter than the hole of the perforated plate. A part of the green sheet pushed into the hole of the perforated plate by pressing the projection of the projection plate against the carrier film by sandwiching a film so as to face the projection plate side, and peeling means having adhesiveness. A method for forming a through-hole, wherein the through-hole is peeled off by using. 2. The method according to claim 1, wherein the peeling means is an adhesive film.