JPS58217471A - Method of sintering ceramic electronic part - 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] The present invention is a barista. f-t star, moisture sensitive resistor.

This invention relates to a method for sintering ceramic electronic components such as ceramic capacitors.

Up until now, the sintering method for ceramic electronic components has been considered important as a factor that greatly affects road material properties.In general, ceramic molded bodies formed into a predetermined shape are made of alumina. The material is placed in a shell made of silica or the like, covered with a lid made of the same material as the shell, and sintered in a tunnel furnace maintained at a certain temperature for several hours. However, during the sintering process, the compact that is in contact with the sintered pod undergoes an interaction with the sintered pod, causing the composition of the compact to change in quality, causing the compact to lose its original properties. . Conventionally, when arranging compacts in a sintered pod to solve this problem, the inner bottom of the sintered pod (1) is made of a material that does not relatively react with the compact (2), as shown in Figure 1. Lay out a flat plate of seven ivy O) and place the seven ivy (3
] Either several molded bodies (2) II are arranged on a plane and sintered, or the molded bodies (2) are placed in a sintered sheath (4) as shown in Figure 2.
5) is spread, and a plurality of molded bodies (5) are arranged on the powder (6) in a plane and sintered.

However, in the case of the method shown in FIG. 1, the lower surface of the molded body (2) in contact with the flat center (3) forms an electrode through interaction with the flat center (3). However, in the case of the method shown in Figure 2, powder (6)
Since the particles dig into the molded body (5) or are attached to the entire surface, it has the same drawbacks as the method shown in FIG.・Therefore, as shown in Fig. 3, a flat center (9) made of a material that does not react with the compact (8) is laid inside the sintered pod (7), and the compact is placed on the center (9). It is conceivable to prevent interaction between the electrode forming portions on both sides and the center (9) on the flat plate by sintering 1! several pieces of (5) upright, but ) In the process of softening the molded body (8) due to the melt-diffusion reaction between the powders constituting the powder, the body of the molded body (8) itself becomes fused to form a flat center (
At the same time, the compact (8) itself shrinks by 10 to 20% during sintering, creating a space between the compacts (8) and causing the compact (8) to tilt. The sintered body (lO) deforms as shown in Figure 4! ! Cracks during other formation f
It had drawbacks such as failure to form a C or 'WL polar acid.

This was especially noticeable when the thickness of the molded body was relatively thin and the number of molded bodies to be arranged was large. In the case of sintering in a sintering sheath, the shape of the center is improved so that when the ceramic molded body is supported by the seven vines, the lowest part of the molded body is higher than the lowest part without coming into contact with the sintering sheath or the seven vines. By supporting the compact at the plow station and at the same time arranging self-supporting separators at arbitrary intervals between multiple compacts, there is no interaction between the electrode forming surfaces on both sides of the compact and the center, and there is no risk of deformation. The object of the present invention is to provide a method for sintering ceramic parts that can produce a sintered body free of sintered parts. An embodiment of the present invention will be described below using a ceramic varistor as an example. That is, as shown in FIG. 5, a plurality of triangular prism-shaped seven vines (12) made of, for example, saponified magnesium are arranged on the bottom surface of a sintered pod (11) made of, for example, alumina or silica, as shown in FIG. and the cross section la# formed between the centers (12)
For example, zinc oxide, iron oxide, #c
The main ingredients are tin chloride, 6&titanium oxide, 7'Cti barium titanate, etc., and several other types of metal oxides are added and mixed, granulated, and then a binder is added and formed into a disk shape. Several varistor molded bodies (14) are arranged in an upright manner, and while the molded bodies (14) are supported, the molded bodies (14) are arranged so that the outer peripheral part of the varistor molded bodies (14) does not come into contact with the sintered sheath (11). It is supported at two locations that are υ higher than the lowest location. In this case, separators (15) made of the same composition as the varistor molded bodies (14) and capable of standing on their own are arranged at arbitrary intervals between the plurality of varistor molded bodies (14). 11) Cover the opening with a lid (not shown) made of the same material as the corresponding jar (11) and sinter it in a tunnel furnace (not shown) maintained at a temperature of 700 to 1600°C for 1 to 10 hours. It is something.

According to such a method of sintering the varistor molded body (14), the contact portions with the center (12) are only two places on the outer periphery supporting the varistor molded body (14), and the varistor molded body (1
4) Electrode formation II can be sintered without contacting not only the sintered pod (11) but also the seven vines (12), so that the contact between the sintered pod (11) and the center (12) on the surface of that part is reduced. The varistor molded body (14) is supported by the support groove (13) with an inclined cross section, and the two positions are higher than the lowest position on the outer periphery. Since the varistor molded body (14) itself is dispersed in two places, and due to the presence of the separator (15), the varistor molded body (14)
) has a small inclination, the deformation of the varistor molded body (14) is greatly alleviated, and deterioration of the varistor characteristics can be prevented.

In the above description, a triangular prism-shaped center was used as an example, and a disc-shaped molded body was used as an example, but as shown in FIG. Using the cylindrical seven ivy (17), as shown in Fig. 8, the flat part (16) is brought into contact with the sintered nail (18), and several vI are arranged at regular intervals, and the partial notch is made. An oblique support groove (17) formed between the cylindrical centers (17)
The same effect can be achieved by arranging a plurality of varistor molded bodies (20) in the shape of a rectangular plate or a disk in an upright manner in 19). In the figure, (21) shows a separator. In addition, in the above embodiment, the separator is arranged at a constant interval between six centers, but as shown in FIG. 9 and FIG. The seven ivy (12) or the partially cut-out cylindrical center (17) are arranged so that they are attracted to each other so that the lowest part does not come into contact with the center (12) or (17) while supporting the varistor molded body. Needless to say, the same effect can be obtained by using a center (23) integrally formed with a support (22) having an inclined cross section as shown in FIGS. 11 to 14. In FIGS. 9 and 10, reference numeral (24) indicates a support groove having an inclined plane. Furthermore, although the above explanation uses a varistor as an example, it can also be applied to a method for sintering ceramic electronic components such as a thermistor, a moisture-sensitive resistor, and a ceramic capacitor, and the same effect cannot be denied.

Next, the effects of the present invention will be explained based on experimental examples. First, 'ZnO82.8 mol% and MgO13.5 mol%
and Biaj)a O, 8 mol%.

SbgOr51.2 mol%, Co00.5 mol%.

Mn00.5mol%, NiO0.5%le% r Cr
2030.2 mol% was added and mixed, granulated, polyvinyl alcohol was added as a binder, and the diameter was 25s111. 400 varistor molded bodies each having a thickness of 1 shoe were manufactured, and the 400 varistor molded bodies were divided into 100 pieces each. Next, as a method for sintering 4 blocks divided into 100 blocks: ■ Example (4) of the present invention using the method shown in FIG. 5 ■ Conventional sintering example (II) using the method shown in FIG. 1 (3) Conventional reference example using the method shown in Figure 2 (C) Conventional reference example using the method shown in Figure 3 Figure 15 and 1st
The results shown in Figure 6 were obtained. In this case, the triangular prism-shaped center in the implementation contingency, example 俤), example (2)
The flat center shown in ) is made of a non-woven material of magnesium oxide, and the reference example (the powder shown in Q is zinc oxide powder, and the electrode is a metal electrode with a diameter of 20 m) is also sintered. The temperature and time are (A) (B) (C)
(2) Both were set at 1300' for 0.3 hours. The separator used in the practical example was made of the same composition as the varistor molded body. Figure 15 is a voltage-reduction characteristic curve diagram, and Figure 16 shows a square waveform of 8 x 20μsea at 400O.
Application when applying surge 11La of A [! 11-
It shows the rate of change of the varistor voltage (VlmA).

As is clear from FIGS. 7 and 8, Example (4) has excellent voltage-current characteristics and varistor voltage change rate characteristics, whereas Reference Example ω) (Q) has excellent voltage-current characteristics and varistor voltage change rate characteristics. It can be seen from the actual example that the current characteristics and the rate of change characteristics of the varistor voltage are inferior, and the effect of actual accidental causes is remarkable.Also, in reference example (2), 6 out of 100 molded bodies cracked during electrode formation. occurs, resulting in poor yield and impractical.

As described above, according to the present invention, when a ceramic molded body is placed in a sintering pod and sintered, a center having a support groove with an inclined cross section is provided in the sintering pod, and When a plurality of plate-shaped ceramic molded bodies are arranged and supported in an upright state, the lowermost part of the outer periphery of the molded bodies is not in contact with the sintered sheath or the center, and the lowermost part is higher than the lowermost part. By arranging separators made of the same composition as the ceramic molded bodies, which can stand on their own at arbitrary intervals between several folded ceramic molded bodies while supporting the ceramic molded bodies in place, property deterioration and deformation can be prevented and ceramic sintering with stable characteristics can be achieved. A method for sintering ceramic electronic components capable of obtaining a solid body can be provided.

[Brief explanation of the drawing]

Figures 1 to 4 are related to conventional reference examples, and Figures 1 to 3 are cross-sectional views showing a state in which a ceramic molded body is housed in a sintered pod, and Figure 4 and Figure 3 are sectional views. FIGS. 5 and 6 are side views showing a varistor molded body obtained by sintering in a state where the varistor molded body is housed in a sintered sheath. FIG. 6 is a perspective view showing the center used in FIG. 5, and FIGS. 7 to 14 relate to other embodiments of the present invention. Fig. 8 is a partially cutaway perspective view showing a state in which a ballista molded body is housed in an arm-tying shell using the center shown in Fig. 7, and Figs. 9 and 10 are perspective views showing the state in which the center is arranged. 11 to 14 are perspective views showing the respective shapes of the center, and FIG.
The figure is a voltage-to-electricity ratio characteristic curve diagram, and FIG. 16 is an IR diagram of the surge application number-varistor voltage change rate characteristic. (11H1B)-----・Sintered pod (12H17
) (23)--------- Center (13) (19) (
22) (24) -------Support groove with inclined cross section (1
4) (20)----1--- Varistor molded body (15
) (21)---1---7 Valet Patent
Applicant Marcon Electronics Co., Ltd. Figure 1 Figure 3 Figure 5 Figure 2 Figure 4 Figure 4 Figure 7 Figure 3 Figure 7 Figure 1 θ Figure 1/Figure 12 Figure 13 1st IJ-Figure

Claims (2)

[Claims] (1) A state in which a sector with a support groove with a 1# surface slope is provided in the sintered pod, a plurality of plate-shaped ceramic molded bodies are arranged in the support groove, and the molded bodies are supported. The lowermost part of the outer periphery of the molded body is supported at two points higher than the lowermost part without contacting the sintered sheath or sector, and the lIl! A method for sintering a ceramic electronic component, characterized in that separators made of the same composition as the molded bodies are disposed between several molded bodies and are sintered so that they are self-supporting at arbitrary intervals. (2) A patented method for sintering electronic components, characterized in that support grooves are provided between each of the seven vines. (31) A method for sintering a ceramic electronic component according to claim 1, wherein the support groove is provided in an integrally molded center.