JP2962895B2 - Manufacturing method of molded ceramic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a molded ceramic capacitor in which ceramic dielectric plates and electrode plates are alternately stacked, and the periphery thereof is covered with an insulating resin by molding.

[0002]

2. Description of the Related Art A conventional molded ceramic capacitor is generally manufactured by the steps shown in FIG. In the first unit assembling step a, the assembling jig unit 1 shown in FIGS. 14 and 15 is assembled. In this assembly jig unit 1, pins 3 are concentrically mounted on a substrate 2 and supported. In the next assembling step b, the terminal fitting 4 is first inserted into the space surrounded by the pins 3 of the assembling jig unit 1, and then the ceramic dielectric plate 5 and the electrode plate 6 are inserted.
Are assembled while alternately applying an adhesive to assemble the capacitor body 7. At this time, the components 4 to 6 are positioned from the outside by the pins 3 so that their centers coincide with each other, and so-called centering is performed.

[0003] In the next adhesive curing step c, the weight 8 is placed on the terminal fitting 4 at the upper end of the capacitor body 7 incorporated in the assembly jig unit 1 and held to cure the adhesive. Usually, heating is performed to accelerate curing, but it takes about one hour to cure. When the adhesive hardens, the assembly jig unit 1 is disassembled in the next jig removal step d, and the capacitor body 7 is removed. In the next molding step e, the removed capacitor body 7 is molded as shown in FIGS. In the figure, first, it is attached to the bottom plate 9 of the molding die. Further, the upper mold 11 is incorporated as shown in FIG. The upper mold 11 is a split-side mold, and a core 12 is disposed at the center of the upper part for centering the capacitor body 7.

In the next preheating step f, the assembled mold and the capacitor body 7 are heated to a predetermined temperature. In the next casting step g, the molding material M is injected from the casting port 13 as shown in FIG. Thereafter, the molding is completed through the steps of a primary curing step h, a mold release step i, and a secondary curing step j, which are ordinary steps of molding.

[0005]

By the way, in the above-mentioned conventional method for manufacturing a molded ceramic capacitor,
There are steps a to d for assembling the capacitor body 7 and a subsequent embedding step e for molding, which causes a problem that the time required for completion is long and the manufacturing cost is high. In addition, since the assembled capacitor body 7 is once removed from the assembling jig unit 1 and then set at a predetermined position inside the mold by embedding, there is a problem that misalignment is likely to occur. The present invention has been made in order to solve the above problems, and aims to reduce the number of steps to shorten the time required for manufacturing, reduce costs, and prevent the occurrence of misalignment. An object of the present invention is to provide a method of manufacturing a molded ceramic capacitor having a good yield.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method of forming a capacitor body by alternately laminating and bonding ceramic dielectric plates and electrode plates, and then forming an insulating resin around the capacitor by molding. In the method of manufacturing a molded ceramic capacitor for covering, the assembly jig is mounted at a predetermined position inside the molding die before assembling and where the capacitor body is supported during a later molding step, and Ceramic jig plate for assembly jig,
After assembling the capacitor body by laminating and bonding while incorporating the electrode plate and terminal fittings, assembling the mold, and then preheating the mold while supporting both ends of the capacitor body with the mold, and bonding the capacitor body to the adhesive layer. Is cured, and an assembling jig is extracted from a mounting hole formed in a mold, and a molding material is injected from the mounting hole.

[0007]

In the present invention, an assembling jig is mounted inside a molding die before assembling, and a ceramic dielectric plate, an electrode plate, and a terminal fitting are assembled into the assembling jig and laminated and bonded. Thereby, the capacitor main body is assembled at a predetermined position in the mold in which the capacitor main body is supported during a later molding step. Next, after the mold is assembled, the mold is preheated while both ends of the capacitor body are supported by the mold, and the adhesive layer of the capacitor body is hardened. Further, the assembly jig is pulled out from the mounting hole of the mold, and the molding material is injected through the mounting hole, whereby the molded ceramic capacitor is manufactured.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a manufacturing process according to the present invention. FIG.
As apparent from the manufacturing process shown in FIG. 13, the conventional unit assembling process a, the assembling process b, the adhesive curing process c, and the jig removing process d are unnecessary as compared with the conventional manufacturing process shown in FIG. The first molding step e in the present invention includes the assembly of the capacitor body 7 performed in the conventional assembling step b.

The next preheating step f includes the curing of the adhesive of the capacitor body 7 performed in the conventional adhesive curing step c. Subsequent steps are configured in substantially the same manner as in the related art.
Next, each of the above-described steps will be described in detail. FIG. 2 is a plan view of the assembling jig 15 used in the first molding step e. FIG. 3 is a front view of the assembling jig 15.
Is a side view thereof.

The assembling jig 15 has a side plate 16 fixed to a substrate 17 by bolts 18. On the substrate 17,
A hole 19 through which a bolt 29 screwed into the terminal fitting 4 at the lower end of the capacitor body 7 is formed. The inner three surfaces of the side plate 16 are arranged so that a virtual columnar body having the same diameter as the capacitor body 7 is circumscribed around the hole 19. That is, the hole 19 is aligned with the center axis of the capacitor body 7, and the terminal fitting 4, the ceramic dielectric plate 5, and the electrode plate 6 are sequentially laminated while being pressed against the side plate 16, thereby centering the capacitor body 7. Can be.

FIG. 5 shows a bottom plate 21 constituting a mold.
22 is a plan view, and FIG. 6 is a cross-sectional view taken along line AA of FIG. The bottom plates 21 and 22 are made of an aluminum material and abut against each other at the joining line B to be integrated. Are formed. further,
In order to insert the assembling jig 15, a hole 26 which is a mounting hole having the same shape as the cross section of the assembling jig 15 is formed with reference to the hole 23.

The hole 23 has a counterbore 27 for fitting the tip of the terminal fitting 4. Hole 2
A recess 20 serving as a space for filling the molding material is formed in a circular area including the holes 24, 25, and 26 with the center at 3. Further, a positioning pin 28 for assembling an upper mold described later is implanted in the bottom plate 22.

FIG. 7 is a plan view showing a state where the assembling jig 15 is fixed to the bottom plates 21 and 22 to assemble the capacitor body 7, and FIG. 8 is a front view of FIG. In the figure, the assembly jig 15 is inserted into the hole 26 of the bottom plate 22 and fixed at a reference position centered on the hole 23, whereby the capacitor body 7 is accurately assembled at the center position of the mold. When assembling the capacitor body 7, first, the tip of the terminal fitting 4 is
The bottom plate 22 is fitted into the counterbore hole 27 of the bottom plate 22.
A bolt 29 is inserted into the hole 23 from the lower surface of the base member 4 and screwed into the tip of the terminal fitting 4 to fix the terminal fitting 4 to the bottom plate 22.

Next, two ceramic dielectric plates 5 and an electrode plate 6 are alternately assembled on the upper surface of the terminal fitting 4, pressed against the side plate 16 of the jig 15, and stacked while applying an adhesive. The terminal fitting 14 is adhered to the uppermost part, and the assembly of the capacitor body 7 is completed. In addition, 31, 3 in the figure
Reference numeral 2 denotes a bolt seat installed in the finished product.
Are fixed to the bottom plate 22 by bolts 33, 34 inserted through the holes 24, 25 from the lower surface of the bottom plate. Also, terminal fittings 4, 14,
An adhesive layer 30 is provided between the ceramic dielectric plate 5 and the electrode plate 6.
Are respectively formed.

FIG. 9 shows that the side dies 36, 37 are attached to the bottom plates 21, 22.
It is a figure which shows the state which attached. The side molds 36 and 37 made of aluminum have a half-split structure, and the side mold 36 is
Positioning is performed by fitting the second positioning pin 28. The bolt 3 is located above the center axis of the capacitor body 7.
A core 42 made of an aluminum material is fixed to the side dies 36 and 37 via a pressing plate 41 fixed to 8, 39.
The core 42 is air-tightly supported between the side dies 36 and 37 via an O-ring 43, and abuts the terminal fitting 14, which is the upper end of the capacitor body 7, at the center of the lower surface.

Here, the bolt 45 inserted through the center hole 44 of the core 42 is screwed into the terminal fitting 14, and the upper end of the capacitor body 7 is fixed at a fixed position. That is, the capacitor body 7 in which the terminal fittings 4 and 14 and the ceramic dielectric plate 5 and the electrode plate 6 are alternately stacked, the upper and lower ends are fixed in addition to the side surfaces supported by the assembling jig 15. Thereby, each part is maintained at a proper position, and the shape of the entire capacitor body 7 is stabilized. The side dies 36, 37
Are assembled into the bottom plates 21 and 22 so that a space S is formed therein. This completes the molding step e.

Next, the process proceeds to the next preheating step f while maintaining this state. In the preheating step f, the entire mold in which the above-described capacitor body 7 is incorporated is heated to a predetermined temperature in preparation for the next casting step g. During the preheating step f, the adhesive layer 30 between the components of the capacitor main body 7 is hardened, and the entire capacitor main body 7 is integrated, and is stabilized alone. In this state, if necessary, the capacitor body 7 may be taken out, and a formal wire may be connected between the terminal fittings 4 and 14 and the electrode plate 6 by soldering. Next, the bolt 29 is removed from the terminal fitting 4 and the substrate 17, and the assembling jig 15 fixed to the bottom plate 22 is pulled out downward.
Is screwed into the terminal fitting 4, and the process proceeds to the casting step g.

The casting step g is performed by assembling the jig 1 from the bottom plate 22.
5 is removed, and the top and bottom are changed.
The mold material M is injected using the hole 26 of the bottom plate 22 into which the hole 5 has been inserted as an injection port. At this time, in the space S inside the mold, the upper and lower sides of the capacitor main body 7 are fixed, so that the capacitor body 7 is maintained at a predetermined center position, and the periphery thereof is filled with the molding material M.

FIG. 10 is a sectional view showing a state after the molding material M has been injected. In this state, the next primary curing step h
Then, the entire mold in which the capacitor body 7 is incorporated is heated to a predetermined temperature. When the molding material M is an epoxy resin, the temperature in the furnace is kept at 100 ° C. and kept for 24 hours. Thereafter, it is completed through a mold release step i and a secondary curing step j, which are ordinary steps of molding.

FIG. 11 is a sectional view of the molded ceramic capacitor C completed through the above steps.
Is a bottom view thereof. In the figure, reference numeral 46 denotes a high-voltage electrode made of the terminal fitting 14, 47 denotes a low-voltage electrode made of the terminal fitting 4, 48
Is a formal line. In this molded ceramic capacitor C, a flange portion F is formed on the low voltage electrode 47 side,
Bolt seats 31 and 32 are provided on the end surface of the flange portion F.

As described above, when manufacturing the molded ceramic capacitor C, the capacitor body 7 is assembled in the molding step e, and the adhesive layer 30 of the capacitor body 7 is cured in the preheating step f. Accordingly, the unit assembling step a, the assembling step b of the capacitor main body 7, the adhesive curing step c, and the jig removing step d, which are conventionally required alone, are not required.
In particular, the time required for the adhesive curing step c is usually one hour, but by reducing this, the manufacturing time is greatly reduced.

Further, since the assembly of the capacitor body 7 is performed in the mold and is continuously cured at the same position, the capacitor body 7 is assembled with high precision, the misalignment is eliminated, the quality is stabilized, and the yield is improved. . The present invention is not limited to the shape and structure of the molded ceramic capacitor C of the embodiment, but similarly applies to other molded ceramic capacitors having a basic structure in which ceramic dielectric plates and electrode plates are alternately stacked. Applicable.

[0023]

As described above, according to the present invention, the assembly of the ceramic dielectric plate, the electrode plate and the terminal fitting is performed in the mold, and the adhesive layer is cured by preheating the mold. As a result, the number of steps is reduced, and the manufacturing time and cost can be reduced. In addition, by assembling the ceramic dielectric plate and the electrode plate, etc. from the beginning at a predetermined position in the molding die, and maintaining the state as it is, the molding is performed. The yield is stably improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a manufacturing process using the present invention.

FIG. 2 is a plan view of an assembly jig used in a molding step.

FIG. 3 is a front view of an assembling jig used in the embedding process.

FIG. 4 is a side view of an assembling jig used in the molding step.

FIG. 5 is a plan view of a bottom plate constituting the mold;

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is a plan view showing a state where the capacitor body is assembled.

FIG. 8 is a front view showing a state where the capacitor body is assembled.

FIG. 9 is a sectional view showing a state in which an upper die is attached to a bottom plate.

FIG. 10 is a cross-sectional view showing a state after a molding material has been injected.

FIG. 11 is a sectional view of the completed molded ceramic capacitor.

FIG. 12 is a bottom view of the completed molded ceramic capacitor.

FIG. 13 is a view showing a manufacturing process of a conventional example.

FIG. 14 is a plan view showing a conventional unit assembly process.

FIG. 15 is a front view showing a conventional unit assembling process.

FIG. 16 is a front view showing a molding step of a conventional example.

FIG. 17 is a cross-sectional view showing a molding and casting process of a conventional example.

[Explanation of symbols]

 Reference Signs List 4 terminal fitting 5 ceramic dielectric plate 6 electrode plate 7 capacitor body 14 terminal fitting 15 assembly jig 19 hole 21,22 bottom plate 23-26 hole 28 positioning pin 29 bolt 30 adhesive layer 36,37 side mold 38,39 bolt 41 Press plate

Claims (1)

(57) [Claims] In a method of manufacturing a molded ceramic capacitor, a ceramic dielectric plate and an electrode plate are alternately laminated and adhered to assemble a capacitor body, and the surroundings are covered with an insulating resin by molding. Inside the molding die, a mounting jig is mounted at a predetermined position where the capacitor body is supported during a later molding process, and a ceramic dielectric plate is mounted on the assembly jig.
After assembling the capacitor body by laminating and bonding while incorporating the electrode plate and terminal fittings, assembling the mold, and then preheating the mold while supporting both ends of the capacitor body with the mold, and bonding the capacitor body to the adhesive layer. A method of manufacturing a molded ceramic capacitor, comprising: curing an assembly jig from a mounting hole formed in a mold; and injecting a molding material through the mounting hole.