JPS6131361A - Manufacture of ceramic wafer - 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 (Field of Industrial Application) The present invention relates to a method of manufacturing a ceramic wafer used for example in capacitors.

(Conventional technology) Conventionally, porcelain wafers are manufactured as follows.

The slurry obtained by mixing the raw materials for the porcelain composition and the organic binder is stretched thinly using a doctor blade or other means to create an unsintered product! A receipt is prepared, and then this unsintered porcelain sheet is cut into a predetermined shape to obtain an unsintered porcelain wafer. As shown in Fig. 2, this wafer a is coated with a thin layer of zirconia or alumina powder C having a particle size of 5 μm, which is an anti-fusing agent to prevent fusion and reaction, on a sintering substrate. The unsintered porcelain wafer is then placed on top of the wafer a, and the process of alternately spreading alumina powder C thinly so that one particle layer is formed on top of the wafer a and placing the unsintered porcelain wafer on top of the unsintered porcelain wafer is repeated. a2... are stacked, and a zirconia sintered plate d, which is about 5 to 10 times thicker than the unsintered porcelain wafer, is placed on the top layer as a weight, and sintered in that state.

(Problems to be Solved by the Invention) In the conventional method for manufacturing porcelain wafers, since the anti-fusing agent is a powder, even if it is spread thinly, the porcelain wafer will have unevenness and a smooth surface cannot be obtained, resulting in practical problems. Many warped porcelain wafers are likely to be produced. If you select whether or not they will pass through a slit of a certain length, about half of them will not be able to pass through.Therefore, these highly warped porcelain wafers are stacked again, and a weight is applied to heat the wafers to about 100°C above the sintering temperature. When reheating at a lower temperature, about 50% of the defects are corrected, but the rest is not corrected and is discarded as defective.

In order to obtain such a ceramic wafer with less warpage, there is a problem in that the number of sintering processes and the waste of materials are increased.

An object of the present invention is to provide a method for manufacturing porcelain wafers that does not have the above-mentioned disadvantages.

(Means for Solving the Problems) The present invention provides an unsintered porcelain wafer made of a ceramic composition raw material and a binder, and an anti-fusing powder made of an anti-fusing agent powder and a binder. are alternately stacked on a substrate, and the unsintered porcelain wafers are sintered and the binder is burned out.

(Function) According to the configuration of the present invention, the unsintered porcelain wafer and the anti-fusing agent wafer are in uniform contact with each other on smooth surfaces, and the front surface of each unsintered porcelain wafer is uniformly pressed. In this state, the unsintered porcelain wafer is sintered and the binder is burned away.

(Example) Example 1 Pb203 228.52 Cj, Ti O□ 53
．． 27 g, lr O□ 81.159 were wet mixed in a ball mill and calcined at 850°C for 2 hours,
1 powder of the porcelain composition was ground again using a ball mill.
00g, polyvinyl butyral 89, and 30g of raw material methyl ethyl ketone were mixed in a ball mill for 15 hours to make a slurry, and this slurry was coated on a polyethylene prephthalate film by the doctor blade method and heated at 80°C.
After drying for 30 minutes, the film was peeled off to produce an unsintered porcelain sheet with a thickness of 801 Lm.

Next, 1102 with a particle size of 3 μm used as an anti-fusing agent
100 g of polyvinyl butyral, 8 g of polyvinyl butyral, and 30 g of methyl ethyl ketone were mixed to prepare an anti-fusing agent sheet having a thickness of 80 uTrL.

These two types of sheets are each shaped into a circular shape with an outer diameter of 30 INRφ, and an unsintered porcelain circular wafer (1) and an anti-fusing agent circular wafer (2) are formed into 150# used for sintering as shown in the first figure. Place these on the l#l square substrate (3) 1-, the anti-fusing agent circular wafer (2) and the unsintered porcelain circular wafer (1).
) The cat stacks 20 sheets alternately in this order.

This was sintered in air at 1200°C under conditions of 2[15°C]. After sintering process, anti-fusing agent circular wafer (2)
Since only the binder was burnt out and the anti-fusing agent was not sintered, when the anti-fusing agent wafer (2) was pressed with a finger, it easily collapsed and became powder, and the sintered porcelain circular wafers were separated from each other. This porcelain circular wafer had a thickness of 80 μm and an outer diameter of 24 mm.

When 1000 circular porcelain wafers thus produced were tested for passing through a 130 gm slit, only 18 did not pass through the slit and were defective.

Example 2 A porcelain wafer was produced in the same manner and under the same conditions as in Example 1, except that 100 g of A1□03 was used instead of 7r02 as the anti-fusing agent. Sample 10
Out of 00 pieces, 21 pieces were defective.

Example 3 Wet-mixed 34 g of BaC03197 and 279.9 g of Ti, performed calcination treatment at 800°C for 2 hours, and re-pulverized the resulting powder to form a porcelain wafer in the same manner and under the same conditions as in Example 1. Of the 111,000 ICo samples I created, 12 were defective.

Example 4 In Example 1, the thickness of the unsintered porcelain wafer was 50 g.
Porcelain wafers were prepared in the same manner and under the same conditions as in Example 1, except that the thickness of the wafer was changed to 401 LTrL. When sorting between good and defective products was carried out using a 65 gm slit, 31 out of 141,000 samples were found to be defective.

Comparative Example 1 Porcelain was prepared under the same conditions and in the same manner as in Example 1, except that instead of the Fa adhesion inhibitor wafer, zirconia powder with an average particle size of 3 am was thinly spread on the unsintered l111 substrate. Created a wafer. 2 for 1000 samples
44 items were defective.

Comparative Example 2 A porcelain wafer was prepared in the same manner and under the same conditions as in Example 4, except that instead of the anti-fusing agent wafer, a thin layer of ZrO powder having an average particle size of 1 uTrL was spread. When sorting was carried out under the same conditions as in Example 4, 307 out of 1000 samples were found to be defective.

(Effects of the Invention) The present invention comprises stacking unsintered porcelain wafers made of a ceramic composition raw material and a binder and anti-fusing agent wafers consisting of an anti-fusing agent powder and a binder on a substrate alternately. Since the binder is burned out when the unsintered porcelain wafer is sintered, there are fewer sintered porcelain wafers that warp to the point of failure, and there is no need for processes such as reheating. There is.

[Brief explanation of the drawing]

FIG. 1 is an enlarged side view, not showing the 8!1 layer state of the unsintered porcelain wafer and the anti-fusing agent wafer in the manufacturing method of the present invention;
FIG. 2 is an enlarged side view showing a laminated state of an unsintered porcelain wafer and anti-fusing agent powder in a conventional manufacturing method. (1) Unsintered porcelain circular wafer (2) Anti-fusing agent circular wafer (3) Substrate patent Applicant Taiyo Yuden Co., Ltd. i.1 Agent Kitamura
Kin 9. 2 people other than 'i

Claims (1)

[Claims] Unsintered porcelain wafers made of a porcelain composition raw material and a binder and anti-fusing agent wafers made of an anti-fusing agent powder and a binder are alternately stacked on a substrate, and the unsintered porcelain wafers are sintered. A method for manufacturing a porcelain wafer, characterized in that the binder is burned out at the same time.