JP3960738B2 - Pressure forming device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure forming apparatus that forms a predetermined shape by applying pressure to a workpiece by a mold.
[0002]
[Prior art]
2. Description of the Related Art There is known a pressure molding apparatus that surrounds a workpiece (a product to be pressed) with a mold and pressurizes and molds the workpiece into a predetermined shape. Examples of the work include multilayer electronic components such as multilayer capacitors. The multilayer capacitor is manufactured by alternately laminating conductive sheets and ceramic green sheets having a predetermined shape, pressurizing in the laminating direction, simultaneously heating to cure the binder between the layers, and firing the ceramic. A conductor having a predetermined shape serves as an electrode, and the fired ceramic layer serves as an insulator. In practice, this is cut into a predetermined shape and used as a circuit element.
[0003]
However, when the parallelism between the surface of the laminate of the conductor sheet and the ceramic green sheet and the surface of the mold that contacts this is not maintained, or when the laminate surface has irregularities, the entire laminate surface is evenly distributed. In some cases, pressurization could not be performed. If the pressure is not evenly applied, pressure-bonding failure of each layer of the laminated body occurs, and the layer peels off, resulting in a defective product. Although it is possible to reduce the crimping failure by increasing the applied pressure or strictly controlling the parallelism of the surface of the laminate, according to the former, the latter increases the size of the pressurizing device. According to this, there is a concern about a decrease in production efficiency.
[0004]
As a method for solving this problem, a technique is known in which a surface of a mold that contacts a laminated body is formed of a flexible elastic member so as to enable uniform pressurization. FIG. 4 shows a schematic view of a pressure molding apparatus using a flexible member. The workpiece 110 is placed on a lower die 112, and an upper die 116 in which a flexible layer 114 is disposed on the surface facing the workpiece is positioned above the workpiece 110. The upper mold 116 includes a rigid frame 118 and the flexible layer 114 coupled thereto. The flexible layer 114 has a larger area in a plane perpendicular to the vertical direction in FIG. On the side of the space between the upper mold 116 and the lower mold 112 and on the side of the flexible layer 114, a horizontal mold 120 is disposed so as to surround them.
[0005]
When the upper mold 116 is crushed, the flexible layer having a rectangular cross-sectional shape bulges out so as to fill the gap portion on the side of the workpiece 110. At this time, the flexible layer 114 fills the gap portion with a flow from above the gap portion indicated by arrow A in FIG. The workpiece 110 is formed by applying pressure from above and the side of the workpiece 110 by the flexible layer 114 deformed as described above.
[0006]
[Problems to be solved by the invention]
When pressurizing the work, a phenomenon occurs in which the work extends in the lateral direction as much as it is reduced by the press die. In particular, when pressure is applied by a member having flexibility as in the above-described conventional example, in addition to the above-described function, the surface of the flexible member that contacts the workpiece expands outward as indicated by arrow B. The phenomenon that the surface of the workpiece extends in the lateral direction occurs.
[0007]
Further, the corner portion of the surface of the workpiece that comes into contact with the pressure-type flexible member is rounded due to the deformation of the flexible member as shown in FIG.
[0008]
Furthermore, when pressurizing the work side surface with a flexible member bulged by pressurization, the pressure from the lateral direction of the work may be insufficient or non-uniform.
[0009]
The present invention has been made to solve the above-described problems, and an object of the present invention is to uniformly pressurize a workpiece so as to obtain a predetermined shape.
[0010]
[Means for Solving the Problems]
In order to solve the above-described problem, a pressure molding apparatus according to the present invention is a pressure molding apparatus that performs pressure molding by surrounding a pressure molded product with a plurality of pressure dies. The first pressure mold to be placed, the auxiliary frame disposed on the first pressure mold so as to come into contact with and surround the pressed object, the pressed object and the auxiliary frame A second pressurizing mold that pressurizes at the same time; and a third pressurizing mold disposed around the side of the space sandwiched between the first and second pressurizing molds.
[0011]
When pressurizing the object to be pressed, pressurize the object to be pressed and the auxiliary frame together to support the side of the object to be pressed with the auxiliary frame, and move in the lateral direction of the object to be pressed. Can be prevented.
[0012]
In particular, when a layer having flexibility is provided on the surface to be in contact with the first or second pressure-type molded object and the auxiliary frame, the lateral expansion of the pressure-molded article is performed. In addition to prevention, sagging of the corners of the pressed product can be prevented.
[0013]
The auxiliary frame may have flexibility, and the height of the auxiliary frame is preferably slightly lower than the height of the pressed product.
[0014]
Further, the auxiliary frame can be a rigid body, and in this case, it is preferable that the height of the auxiliary frame is slightly higher than the height of the pressed product.
[0015]
Furthermore, the outer shape of the auxiliary frame is smaller than the surface on which the first pressure-type object to be pressed is placed, and the second pressure-type object to be pressed and the surface in contact with the auxiliary frame are It can be larger than the auxiliary frame outline.
[0016]
According to another aspect of the present invention, a pressure molding method is provided. That is, the pressure molding method of the present invention is a method of performing pressure molding by enclosing a molded object to be compressed with a plurality of pressure molds, and applying pressure to the molded object on the first pressure mold. Placing the auxiliary frame on the first pressure mold so as to come into contact with and surround the pressure-molded article placed above, and above the first pressure mold. A step of arranging a second pressure mold; a step of arranging a third pressure mold around a side of a space between the first and second pressure molds; and a molding object to be pressurized by the second pressure mold. And pressurizing the auxiliary frame simultaneously.
[0017]
Furthermore, the said 1st or 2nd pressurization type shall have a flexible layer which has a softness | flexibility in the surface which contacts a to-be-pressurized molded object and the said auxiliary | assistant frame.
[0018]
According to still another aspect of the present invention, a method for manufacturing a laminated electronic component is provided. The press-molded product of the pressure molding method described above is a laminate in which conductor sheets of predetermined shapes and ceramic green sheets are alternately laminated, and ceramic is also fired when the laminate and the auxiliary frame are pressed. Like that. A laminated electronic component is manufactured by cutting the fired laminate into a predetermined shape.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings. FIG. 1 shows a main configuration of a pressure molding apparatus according to this embodiment. The workpiece 10 is a multilayer capacitor that is the above-described multilayer electronic component. The workpiece 10 is placed on the lower mold 12. An auxiliary frame 22 is disposed around the side of the work 10. As shown in FIG. 2, the auxiliary frame 22 has an inner surface 24 that is in contact with substantially the entire circumference of the workpiece 10. Further, the surface on which the workpiece 10 and the auxiliary frame 22 of the lower mold 12 are placed is a large surface extending outward from the outer shape of the auxiliary frame 22. Above the workpiece 10 and the auxiliary frame 22, the upper die 16 in which the flexible layer 14 is disposed on the surface facing the workpiece 10 and the auxiliary frame 22 is located. The surface of the upper mold 16 that contacts the workpiece 10 and the auxiliary frame 22 is also a large surface that extends outward from the outer shape of the auxiliary frame 22. The upper mold 16 includes a rigid frame 18 and the flexible layer 14 coupled thereto. The flexible layer 14 has a larger area on the plane perpendicular to the vertical direction in FIG. 1 than the surface where the workpiece 10 and the auxiliary frame 22 are combined. On the side of the space between the upper mold 16 and the lower mold 12 and on the side of the flexible layer 14, a horizontal mold 20 is disposed so as to surround them.
[0020]
When the upper mold 16 is crushed, the flexible layer 14 having a rectangular cross-sectional shape pressurizes the workpiece 10 and the auxiliary frame 22 simultaneously. The member forming the flexible layer 14 bulges so as to fill the gap portion on the side of the auxiliary frame 22. The flexible member that moves to the bulging portion is one above the gap portion and one above the auxiliary frame 22, and there is little flow of the flexible member to the side above the workpiece 10. As a result, the lateral extension of the upper surface of the workpiece 10 is suppressed. Moreover, the extension to the side of the workpiece 10 can also be suppressed by the auxiliary frame 22 itself. That is, the auxiliary frame 22 acts to stop the work 10 from extending. This effect can be expected even when the surface of the upper die 16 in contact with the workpiece is not a flexible member, that is, when there is no flow to the side of the upper die surface member.
[0021]
Further, as shown in FIG. 3, the flexible layer 14 flows into the gap portion on the side of the auxiliary frame 22, so that the corner portion of the workpiece 10 is not rounded. Further, the distribution of pressure applied by the flexible layer 14 to the outer peripheral surface of the auxiliary frame 22 tends to be large above the auxiliary frame 22 and small below. However, since the auxiliary frame 22 is interposed between the workpiece 10 and the bulging flexible layer 14, the pressure acting on the side surface of the workpiece 10 becomes substantially equal.
[0022]
Simultaneously with pressurization by the mold, heating is performed to cure the binder between the respective layers, and further firing the ceramic. Thereby, the conductor of the workpiece 10 (laminated body) becomes an electrode, and the fired ceramic layer becomes an insulator. Then, this is cut into a predetermined shape and used as a circuit element. For heating, the lower mold 12 and the upper mold 16 have heating means built therein, and the mold is heated, and this heat is transmitted to the workpiece 10.
[0023]
The auxiliary frame 22 is made of the same or equivalent material as the flexible layer 14. Specifically, fluorine rubber, silicon rubber, NBR (acrylonitrile butadiene rubber), or the like can be used. In this case, it is preferable that the dimension (thickness) of the auxiliary frame 22 in the vertical direction in FIG. Thereby, a sufficient pressure can be applied to the corner of the workpiece 10 from above. The auxiliary frame 22 can also be formed as a rigid body such as a metal. In this case, it is preferable to make it slightly larger than the thickness of the workpiece 10.
[0024]
The inner side surface shape of the auxiliary frame is determined according to the outer peripheral shape of the workpiece. If the work is a disk, the shape of the inner surface of the auxiliary frame is a circle. Further, the outer surface shape of the auxiliary frame is not limited to a square shape as shown in FIG. Further, the workpiece is not limited to the laminated electronic component.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a main configuration of an embodiment.
FIG. 2 is a diagram illustrating examples of shapes of a workpiece and an auxiliary frame.
FIG. 3 is a diagram for explaining a pressure distribution in the vicinity of an auxiliary frame.
FIG. 4 is a diagram showing a main configuration of a conventional pressure molding apparatus.
FIG. 5 is a diagram showing an example of the shape of a workpiece when pressed by a conventional apparatus.
[Explanation of symbols]
10 work, 12 lower mold, 14 flexible layer, 16 upper mold, 20 horizontal mold, 22 auxiliary frame.

Claims (3)

A pressure molding apparatus that surrounds a press-molded product with a plurality of pressure dies and performs pressure molding,
A first pressure mold for placing the object to be pressed;
An auxiliary frame disposed on the first pressure mold so as to come into contact with and surround the object to be pressed;
A second pressure mold for simultaneously pressing the object to be pressed and the auxiliary frame;
A third pressurization mold disposed around a side of the space sandwiched between the first and second pressurization molds;
I have a,
The first or second pressurizing mold has a flexible layer having flexibility on a surface that comes into contact with the pressed molding and the auxiliary frame,
The third pressurizing mold is disposed so as to surround a side of the flexible layer;
The auxiliary frame is a rigid body, the height of which is slightly higher than the height of the pressed product,
Pressure molding device. It is a method of performing pressure molding by enclosing a material to be pressed with a plurality of pressure dies and applying pressure,
  A step of placing a pressed object on the first pressure mold;
  A step of placing an auxiliary frame on the first pressure mold so as to come into contact with and surround the press-molded product placed above;
  Disposing a second pressure mold above the first pressure mold;
  Disposing a third pressure mold around a side of a space sandwiched between the first and second pressure molds;
  A step of simultaneously pressurizing the object to be pressed and the auxiliary frame by the second pressure mold;
Have
  The first or second pressurizing mold has a flexible layer having flexibility on a surface that comes into contact with the object to be pressed and the auxiliary frame, and the third pressurizing mold has a side of the flexible layer. Placed around,
  The auxiliary frame is a rigid body, the height of which is slightly higher than the height of the pressed product,
Pressure molding method. A step of alternately laminating sheets of a predetermined-shaped conductor and ceramic green sheets to form a laminate;
  Placing the laminate on a first pressure mold;
  Placing the auxiliary frame on the first pressurizing mold in contact with the periphery of the laminated body placed above and having a shape surrounding it;
  Disposing a second pressure mold above the first pressure mold;
  Disposing a third pressurization mold around a side of a space sandwiched between the first and second pressurization molds;
  A step of simultaneously pressurizing and firing the laminate and the auxiliary frame by the second pressure mold;
  Cutting the fired laminate into a predetermined shape and forming a laminated electronic component;
Have
  The first or second pressurizing mold has a flexible layer whose surface contacting the laminated body and the auxiliary frame has flexibility, and the third pressurizing mold is disposed so as to surround a side of the flexible layer. And
  The auxiliary frame is a rigid body, the height of which is slightly higher than the height of the pressed product,
A method for manufacturing a laminated electronic component.

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