JPS6146013A - Method of producing ceramic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION 2 (Field of Industrial Application) The present invention relates to a method of manufacturing a ceramic capacitor, and particularly to a method of manufacturing a multilayer ceramic capacitor, for example.

(Prior art) The conventional manufacturing method for multilayer ceramic capacitors is as follows:
After dispersing dielectric powder in an organic binder solution to form a mud-like ceramic paste, the ceramic paste is formed into a sheet shape and dried by heating, for example, with a heater to obtain a ceramic green sheet. An electrode paste containing a mixture of gold mud powder and, for example, Fes is printed on the surface of this ceramic green sheet and dried by heating to form an electrode paste J'ffl. Furthermore, a number of these layers are piled up and pressed together as required to obtain a laminate.

The laminate is burnt out (calcined) and fired using a firing machine. Furthermore, external electrodes are formed on the fired chip-like laminate to produce a laminate type ceramic or vine capacitor.

(Problems to be Solved by the Invention) When pre-drying and curing the electrode paste layer and the ceramic paste layer, it takes a long time to cure, and therefore the process takes a lot of time. This is one of the factors that hinders improvement in mass productivity.

Therefore, the main object of the present invention is to provide a method for manufacturing a ceramic capacitor, which can cure a ceramic paste layer and an electrode paste layer in a short time and improve mass productivity.

(Means for Solving the Problems) In this invention, a ceramic paste is made by mainly mixing a dielectric powder and an electron beam curable resin, and an electrode paste is made by mainly mixing a metal powder and an electron beam curable resin. . First, a layer of ceramic paste or electrode paste is formed and then hardened by irradiating it with an electron beam. Then, a layer of electrode paste or ceramic paste is formed on top of the hardened layer and then the layer is irradiated with an electron beam. and then let it harden.

(Function) The ceramic paste layer is instantly hardened by being irradiated with an electron beam, and the electrode paste N is similarly hardened instantly by being irradiated with an electron beam.

(Effects of the Invention) According to the present invention, the ceramic paste layer and the electrode paste layer can be cured simply by irradiating them with electron beams, so that the curing time is shorter than that in the conventional case of heating and drying. It cannot be significantly shortened. Therefore, a dramatic improvement in the mass productivity of ceramic capacitors can be expected. Furthermore, each paste layer is already cured by electron beam irradiation, and there is no need to carry it to a furnace for drying and curing after printing and forming each paste +-i as in the past. Since there is no need to increase the mechanical strength of each layer, it is possible to make the ceramic paste layer and electrode paste layer thinner, which not only saves materials but also provides a ceramic capacitor with high capacitance. .

Furthermore, if the same electron beam curable resin is used as the binder for the ceramic paste and the electrode paste, the adhesion between the layers will be good during lamination, and no peeling will occur.

Furthermore, if the same electron beam curable resin is used, the firing (burnout) of each layer proceeds simultaneously, resulting in a dense sintered product. In other words, in the conventional method, the face of the electrode paste and the binder of the ceramic paste are made of different materials, and when a laminate of the electrode paste layer and the ceramic green sheet is fired at the same time, the face first becomes low-molecular and carbonizes. The binder is then scattered.

During this firing, because the faces are scattered to the outside, passages are created between the ceramic particles of the ceramic green sheet. This path will be restored later as the ceramic particles grow due to temperature, but since the binder is blown away after the face is blown away, the path will be opened again in the ceramic green sheet and another A new passage will be created. Such passages also subsequently fill and stabilize, but never completely. Therefore, the ceramic layer ends up being porous.

And when it comes to a porous ceramic layer like this,
"Layer peeling" or delamination between the ceramic layer and the electrode layer occurs, resulting in a defective product. On the other hand, if the same resin is used, burnout occurs in the electrode layer and the ceramic layer at the same time, so the path that occurs when the binder scatters is formed only once, and furthermore, the binder does not scatter afterwards. Since there are no such passages, the growth of ceramic particles will almost completely fill up such passages. Therefore, the ceramic layer becomes relatively dense and does not cause "layer peeling" or delamination from the electrode layer. Therefore, the yield in the process is improved, and mass productivity can be further improved.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Example) FIG. 1 is an illustrative diagram showing a method for manufacturing a multilayer ceramic capacitor according to an example of the present invention, step by step.

In the following explanation, a method for manufacturing an 8M capacitor will be exemplified, but it will be appreciated that the present invention can be applied to the manufacturing of any type of capacitor such as other ceramic capacitors, such as single-plate capacitors and cylindrical capacitors. Please point it out in advance (.

First, as shown in FIG. 1(A), a base 10 made of, for example, glass, metal, or ceramic is prepared.

Next, as shown in FIG. 1(B), a film is printed on the base 10 by, for example, a screen printing method or a doctor blade method.
A first ceramic paste layer 12a is formed. Ceramic paste is mainly a mixture of dielectric powder and electron beam curable resin. Examples of the electron beam curable resin include monomers and oligomers of acrylate compounds, such as epoxy acrylate, polyester acrylate, urethane acrylate, unsaturated polyester, unsaturated polyether, urethane melamine acrylate, vinyl polybutadiene, acrylic urethane, and acrylic polyester. etc. are available.

Next, as shown in Fig. 1(c), ceramic paste)
The fit 12a is irradiated with an electron beam to harden the ceramic paste layer 12a. An electron beam irradiation time of 1710 seconds or less is sufficient.

Then, as shown in FIG. 1CD), a first electrode paste layer 14a is formed on the hardened ceramic paste layer 12a by, for example, a screen printing method or a spray method. This electrode paste is a mixture of the same electron beam curing resin as the ceramic paste and mainly metal powder. In this way, the electron beam curing resin contained in the electrode paste may be the same as that contained in the ceramic paste, but depending on the materials to be mixed, such as the difference between dielectric and metal, etc. Different resins may be used.

As shown in FIG. 1(E), the electrode paste layer 14a is irradiated with an electron beam to harden the electrode paste N14a.

In this way, ceramic paste) J
W12a is formed and cured, then the electrode paste) Fi
14a is laminated and cured.

Since it is a multilayer capacitor, the process returns to the step shown in FIG. 1(B) and the hardened electrode paste N1
4a, the next ceramic paste 512b is formed, and then the ceramic paste Fi 12b is irradiated with an electron beam and hardened in the same manner as the step shown in FIG. 1(c).

Furthermore, the next electrode paste layer 14b is formed on the hardened ceramic paste (J'1ii) 12b in the same manner as the step shown in FIG. 1(D), and the electrode paste layer 14b is The electrode paste layer 14 is irradiated with a wire.
Harden b.

By repeating this process several times, as shown in FIG.
i12a, 12b, 12c, 12d and 12e are formed, and electrode pastes 14a, 14b,
Laminate 2 in which each of 14c and 14d is formed
Get 0. In this case, for example, ceramic paste H
If the electrode paste layers 12a to 12e and the electrode paste layers 14a to 14d are rectangular, at least one of the edge and lateral dimensions of the electrode paste layers 14a to 14d are shorter than those of the ceramic paste J'112a to 12e.

The electrode paste layers 14a and 14c have one end aligned with one end of the ceramic paste N12a to 12e, and the electrode paste layers Ji14b and 144 have one end aligned with the ceramic paste WJ.
12a to 12e are aligned and stacked.

That is, each of the electrode paste layers 14a to 14d has its other end alternately connected to the ceramic paste layer 12.
The layers a to 12e are stacked so that the shortened dimension described above is separated from the other end.

Next, as shown in FIG. 1(G), ceramic paste layers 12a to 12e and electrode pastes Fi14a to 1 are formed.
The laminate 20 of 4d is removed from the base 10 and fired in a firing furnace to obtain a fired laminate 20. At this time, if the binder, that is, the electron beam curing resin contained in each ceramic paste layer and the electrode paste H is the same, they will be scattered at the same time.

Finally, as shown in FIG. 1(H), external electrodes 116a and 116b are placed on both sides of the fired laminate 120.
form each. The external electrode 116a is the electrode layer 114
a and the electrode layer 114C, and the external electrode 11
6b is commonly connected to the electrode layer 114b and the electrode layer 114 (i. Therefore, the external electrodes 116a and 116
The capacitances of the ceramic layers 112a to 112e are formed or connected in parallel between the ceramic layers 112a to 112e.

FIG. 2 is an illustrative diagram specifically showing each step of FIG. 1(B) to FIG. 1(E).

In this example, first, a ceramic paste (ceramic paste) is placed on the base 10.
]'W12a is formed. Then, move this laminate in the direction shown by arrow A in FIG. 2, and paste the ceramic paste JW.
12a is irradiated with an electron beam. Next, an electrode paste is printed on the hardened ceramic paste layer 12a to form an electrode paste N14a, and the laminate is formed into a second layer.
Move in the direction shown by arrow B in the figure and irradiate the electron beam at the same position. What is necessary is just to repeat such a process as needed.

[Brief explanation of the drawing]

FIG. 1 is an illustrative diagram showing step by step a method for manufacturing a multilayer ceramic capacitor as an embodiment of the present invention. FIG. 2 is an illustrative diagram showing a method of irradiating the ceramic paste (Ff) and electrode paste layer with an electron beam. In the figure, 12a to 12e are ceramic paste layers,
142-14d are electrode paste layers, 112a-112e
indicates a fired ceramic layer, and 114a to 114d indicate fired electrode layers. Patent applicant Murata Manufacturing Co., Ltd. Representative Patent attorney Oka 1) Zen Kei (one idiot) Figure 1 Figure 2 Figure 10'

Claims (1)

[Claims] 1 (a) preparing a ceramic paste by mainly mixing a dielectric powder and an electron beam curable resin; (b) preparing an electrode by mainly mixing a metal powder and an electron beam curable resin; (c) forming one layer of the ceramic paste and electrode paste; (d) curing the one layer by irradiating the one layer with an electron beam; (e) on the one layer. forming the other layer of the ceramic paste and the electrode paste, and (f) curing the other layer by irradiating the other layer with an electron beam, any of the steps (c) to (f) A method for manufacturing a ceramic capacitor, the method comprising: repeating the above steps as necessary, and further comprising: (g) firing a laminate of the ceramic paste and the electrode paste. 2. The method of manufacturing a ceramic capacitor according to claim 1, wherein the same electron beam curable resin is used in steps (a) and (b).