JPH02117117A - Manufacture of laminated ceramic capacitor - Google Patents

Abstract

PURPOSE:To obtain a laminated ceramic capacitor which can be produced by transferring dielectric layers at a low temperature by means of a hot stamping system without the need of using a large amount of binder in the dielectric layers, by providing a green sheet having an adhesive layer formed partially on the surface of a dielectric layer into a meshy or spotted form and transferring the dielectric layer to an object to be transferred while exerting heat and pressure onto the base film of the green sheet. CONSTITUTION:A dielectric layer 4 consisting of dielectric powder 2, a plasticizer and a binder 3 is provided on a base film 1, and an adhesive layer 5 is applied thereon partially in to a meshy or spotted form. A hot-stamping sheet thus produced is applied against a dielectric layer having inner electrodes printed thereon, so that the dielectric layer 4 on the base film 1 is transferred thereto by exerting heat and pressure onto the base film 1. A laminated ceramic capacitor is produced in this manner. According to this method, dielectric layers can be laminated at a low temperature by means of a hot stamping system.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a multilayer ceramic capacitor.

Background of the Invention In recent years, with the development of ultra-compact, thin, and lightweight electronic devices such as radios, microcassettes/7 recorders, electronic tuners, and video cameras, there has been a strong demand for smaller and larger capacity capacitors used as circuit elements. It has become. A multilayer ceramic capacitor is known as a component that satisfies these requirements.

The method for manufacturing multilayer ceramic capacitors is to first form a ceramic dielectric layer several tens of micrometers thick on an organic film using a doctor blade method using a nullary consisting of dielectric powder, a binder, a plasticizer, and an organic solvent, and then form a green sheet. Create. Next, a plurality of sheets with internal electrodes printed on them are stacked and pressed together to create a laminated molded body, which is then cut into chip shapes, fired, and then external electrodes are formed. (“Insulating Dielectric Ceramic 7” CMC
On the other hand, in order to achieve even higher capacity, it is desirable to make the dielectric layer thinner, but since there is a limit to the thickness of the dielectric layer in the doctor blade method, By increasing the amount of binder than before and further reducing the nullary viscosity, we created a thin sheet of 10 μm or less using the river crawl method.Using the large amount of binder, we created a dielectric sheet from the vane film side of the green sheet by thermocompression bonding. The so-called ho, which transfers the body layer.

A method of laminating dielectric layers using the Tonu-Tamp method has also been recently proposed.

The lamination process of a laminated ceramic capacitor using the hot stamping method will be briefly explained using FIG.

Using a nullary prepared by adding a binder, a plasticizer, a solvent, etc. to dielectric powder and mixing it, an ultra-thin dielectric layer 6.11 of several μm to several tens of μm is formed on the base film 1o by a river crawl method or the like. Form and create hot stamp sheets. In this case, the composition of the dielectric layer 6 must contain an amount of binder that enables hot stamping. Internal electrodes 7 are formed on the dielectric layer 6 surface of this hot stamp sheet, and then another hole 7) is formed.
The stamp sheets 8 are overlapped, and then heat and pressure are simultaneously applied from the base film 10 side using a heat roller 9 or the like to form the dielectric layer 11 of the hot stamp sheet 8 into the dielectric layer 6 on which the internal electrodes 7 are printed. After that, the Peine film 10 of the hot stamp sheet 8 is peeled off.

After forming internal electrodes on this peeled surface, the layers are laminated by repeating the steps of overlapping another hot stamp sheet, transferring by thermocompression, peeling off the base film, and forming electrodes. In addition, in FIG. 2, 12 is a heater, and 13 is a heater.
is the stand for the Ho-notonutamp device.

Problems to be Solved by the Invention E. 7 In order to enable thermal transfer, green sheets using the tonutamp method contain a larger amount of binder than green sheets made using the conventional method, making it difficult to remove the binder when firing a laminated molded product. This is also a cause of peeling between the dielectric layer 6 and the internal electrode 7 after curing. Further, when the number of laminated layers increases and the amount of binder is large, electrode displacement of the internal electrodes 7 occurs due to heat and pressure during lamination, resulting in problems such as a decrease in capacitance as a capacitor.

In view of the above-mentioned problems, the present invention aims to provide a method for manufacturing a multilayer ceramic capacitor that can be transferred at low temperatures and that can be transferred without using a large amount of binder in the dielectric layer. .

Means for Solving the Problems In order to solve the above problems, the green sheet used in the multilayer ceramic capacitor of the present invention has a dielectric layer made of dielectric powder, a binder, a plasticizer, and a partial layer formed on the surface of the Baine film in this order. An adhesive layer is provided on the surface. The dielectric layer is then laminated by applying heat and pressure from the base film side of the green sheet to transfer the dielectric layer to the object.

Function FIG. 1 shows an example of a green sheet used in manufacturing the multilayer ceramic capacitor of the present invention. The green sheet in Figure 1 has two layers of dielectric powder on one side of the base film. It has a structure in which a dielectric layer 4 made of a plasticizer and a binder 3 is provided, and an adhesive layer 6 is partially formed on the surface thereof in the shape of a network or spots. Using a hot stamp sheet with such a structure, heat and pressure is applied to one side of the base film of the green sheet in the same manner as shown in Figure 2, and the bake film 1 is placed on the dielectric layer on which internal electrodes are printed. It is assumed that a multilayer ceramic capacitor is created by transferring the dielectric layer 4 of . If dielectric layers were to be laminated using the Hontonutanbu method without a conventional adhesive layer, a large amount of binder would be needed to soften the binder in the dielectric layer and make thermal transfer possible during heat-press bonding. However, the green sheet used in the manufacturing method of the present invention has a pressure-sensitive adhesive layer that is softened and fixed at low temperature [E] partially formed in the shape of a network or spots on the surface of the dielectric layer. Therefore, the dielectric layers can be easily laminated together by a hot stamping method at a low temperature without requiring any special binder in the dielectric layers.

Therefore, when using the conventional E7) Nutanbu type green sheet, it is easy to remove the binder and low temperature transfer is possible, so that electrode displacement does not occur even when a high number of layers are stacked. Note that if an adhesive layer is formed on the entire surface of the dielectric layer, the thermal transfer during horitonutamping will be good, but the organic adhesive will thermally decompose during firing and generate a large amount of adhesive, so there will be a gap between the dielectric layers in the sintered body. A large number of delaminations occur.

Example Specific embodiments of the present invention will be described in detail.

BaTi0. After blending 12 parts by weight of polyvinyl butyral resin and 2 parts by weight of dioctyl phthalate with 100 parts by weight of dielectric powder mainly composed of
Seven rallies were prepared with a viscosity of s. After degassing this nullary, a dielectric layer 4 with a thickness of 9 μm was formed on a Borien ether film with a thickness of 60 μm by a reverse roll method. Next, a thermoplastic acrylic-nutyrene-salt-acid-vinyl-pi-based adhesive layer 6 with a thickness of 1 μm was formed in a network shape by a gravure coating method on the dielectric layer 4 to prepare a green sheet. The ratio of the surface on which the adhesive layer 6 was formed and the surface on which the adhesive layer 6 was not formed on the surface of the dielectric layer 4 was 1:1. For comparison, a sheet was also prepared in which an adhesive layer made of the same adhesive as described above was formed on the entire surface of the dielectric layer 4.

Next, in accordance with the method shown in FIG. 2, a highly laminated molded product consisting of 50 layers was formed by hot stamping using the two types of green sheets described above.

The temperature at the time of stamping was 100℃ and the pressure was 26℃.
Ky/cd. Furthermore, commercially available Pd paint was used as the internal electrode. After that, after cutting into chunks, the chip molded body was heated at 1000° while being sprinkled in ZrO2 powder.
It was baked at C for 2 hours. The laminated chip created in this way,
The fine structure inside the sintered body of the HUP capacitor was observed using a scanning electron microscope. As a result, when using a sheet in which the adhesive layer 5 was formed on the entire surface of the dielectric layer 5, the trial amount was 2Q.
In all of the capacitors, delamination occurred between the dielectric layer 4 and the internal electrodes, making it impossible to use them as capacitors. On the other hand, in the sintered body using a green sheet in which the adhesive layer S was partially formed on the dielectric layer 4 surface, no delamination was observed and there was no displacement of the internal electrodes. Further, as a result of measuring the capacitance, it was confirmed that the variation in capacitance was within ±1% of the theoretically calculated value for 60 measurements, and that the capacitance accuracy was high.

Note that even if a green sheet consisting only of the dielectric layer 4 having the same composition as used in this example was hot stamped under exactly the same conditions as described above, thermal transfer could not be achieved. Note that thermal transfer is only possible when the amount of binder is increased to create a dielectric layer sheet with a composition of 100 parts by weight of dielectric powder, 20 parts by weight of polyvinyl butyral resin, and 2 parts by weight of phthalate, and the temperature in that case is 186°C. °
It was C.

As is clear from the above results, dielectric powder.

When using a green sheet for laminated ceramic capacitors in which an adhesive layer 6 is partially formed on the surface of a dielectric layer 4 made of a binder and a plasticizer, it is possible to laminate layers using the Ho-Sotonutan method at a temperature 86°C lower than conventional methods. As a result, there was no misalignment of the internal electrodes, and the accuracy of the capacitance was greatly improved.

In addition, by partially forming the adhesive layer 6 on the surface of the dielectric layer 40, the dielectric layer 4K can be laminated by thermal transfer even if it does not contain a particularly large amount of binder, making it easy to remove the binder during firing. It was possible to significantly suppress the occurrence of delamination in the sintered body.

In the embodiment, the adhesive layer 5 is formed in a mesh shape on the surface of the dielectric layer 4, but the same effect can be obtained even if it is formed partially in spots, stripes, etc.

In addition, although this case study deals with multilayer ceramic capacitors, other multilayer ceramic electronic components that can be stacked using the hot stamping method, such as multilayer actuators, multilayer barinutors, etc.
It goes without saying that the same effect can be obtained even when applied to a laminated substrate.

Effects of the Invention As described above, the method for manufacturing a multilayer ceramic capacitor according to the present invention is based on the base film ff1 of a green sheet having a structure in which an adhesive layer is partially formed in the form of a network and spots on the surface of a dielectric layer. (Ill Color Heat!: It has a lamination process that transfers the dielectric layer to the object by applying positive pressure.The amount of binder in the dielectric layer is higher than when using a conventional hot nut sheet.) Thermal transfer can be carried out at low temperatures even if the amount of heat is reduced.Therefore, the occurrence of delamination can be suppressed or the positioning accuracy of the electrode can be improved, thereby increasing the accuracy of electromagnetism, and its industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a green sheet for a laminated ceramic capacitor used in the manufacturing method according to the present invention, and FIG. 2 is a sectional view illustrating the lamination process when laminating using a hototonutamp sheet. 1...Baine film, 2...Dielectric powder, 3...Plasticizer, binder, 4...
- Dielectric layer, 6...Adhesive layer. Name of agent: Attorney Shigetaka Awano and 1 other person 1st
Figure 2 Figure 1 ・− −m− 3−・− Base full dielectric material 8 禾可′Mj? J, Bainta Ronden Junsoso i slayer =:===)

Claims (1)

[Claims] A green sheet is formed by providing a dielectric layer made of dielectric powder, a binder, and a plasticizer on the base film surface, and partially providing an adhesive layer on the dielectric layer surface. A method for manufacturing a multilayer ceramic capacitor, comprising the step of laminating a dielectric layer by applying pressure and transferring the dielectric layer to an object.