JPH05246756A - Ceramic substrate - Google Patents

Abstract

PURPOSE:To obtain a ceramic substrate having high elongation and hardly causing cracking by adding a polyester type plasticizer and a binder to ceramic powder and carrying out mixing, kneading, forming into a sheet and firing. CONSTITUTION:A polyester type plasticizer is added to ceramic powder of 0.2-0.8mum particle diameter such as alumina-talc powder by 0.5-4 pts.wt. per 100 pts.wt. of the ceramic powder and a binder such as methylcellulose is further added by 1-30 pts.wt. per 100 pts.wt. of the ceramic powder. They are mixed and kneaded with three rolls, etc., to obtain body and this body is formed into a sheet with an extruder, etc. This sheet is blanked and the resulting green sheet is fired to obtain the objective ceramic substrate.

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 ceramic substrate used as a mounting substrate for various electronic elements.

[0002]

2. Description of the Related Art Conventional ceramic substrates are refractory aggregates,
Although a ceramic substrate is obtained by kneading a combustion aid and a binder into a sheet and then firing the sheet, there is a problem that cracks are likely to occur in the sheet during the sheet punching process because the sheet has a very small elongation. However, cracks in the ceramic substrate hinder the circuit pattern drawn on the substrate surface, and in recent fine patterns, they have caused circuit disconnection and short circuits.

[0003]

As described in the prior art, the conventional ceramic substrate has a drawback that cracks easily occur. The present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is to provide a ceramic substrate that has elongation and is unlikely to cause cracks.

[0004]

According to the present invention, a polyester type plasticizer and a binder are added to and mixed with ceramic powder.
Since the ceramic substrate is characterized by being kneaded, formed into a sheet, and then fired, the above object can be achieved. The present invention will be described in detail below.

The ceramic powder used in the present invention includes refractory aggregates such as alumina, magnesia, silica, nitride, boron, etc., ceramic powder, combustion aids such as talc, calcia, yttrium, etc. However, the particle size is 0.2
It is preferable to use one having a diameter of .about.0.8 micron. That is, if the particle size exceeds 0.8 μm, cracks tend to occur. As the polyester type plasticizer, any polyester type may be used as long as it is a polyester type, but a polymer type is preferable. The addition amount of the polyester type plasticizer is preferably 0.5 to 4 parts by weight (hereinafter simply referred to as “part”) with respect to 100 parts by weight of the ceramic powder. That is, if it is less than 0.5 part, it is difficult to reduce cracks, and if it exceeds 4 parts, the formability tends to decrease. As the binder, methyl cellulose, acryl, vinyl acetate, urea resin, melamine resin, phenol resin or the like can be used. It is desirable that the amount of the binder be as small as possible, preferably 1 to 30 parts per 100 parts of the ceramic powder. That is, if it is less than 1 part, it is difficult to mold, and if it exceeds 30 parts, the traces of bubbles increase. Kneader for mixing and kneading,
A commonly used one such as a vertical kneader, a mixer, a roll, an extruder or the like is used and is not particularly limited. An extruder, a roll or the like can be used for forming a sheet. As for the firing method and the firing apparatus, those commonly used can be used as they are.

The present invention will be described below based on examples.

[0007]

Example Ceramic powder 10 obtained by adding 4 parts of talc to 96 parts of alumina having a particle size of 0.4 micron and mixing them
To 0 parts, add 6 parts of methyl cellulose and 2 parts of polyester type plasticizer (Nippon Yushi Co., Ltd., trade name Nonion), and add 3 parts.
It mixed and kneaded with this roll and obtained the clay. Next, the clay is formed into a sheet having a thickness of 1.0 mm by an extruder and 400 × 400 mm.
The green sheet obtained by punching was heated to 1600 ° C. at a heating rate of 100 ° C./hour, fired at 1600 ° C. for 2 hours, and then cooled to obtain a ceramic substrate.

[0008]

[Comparative Example] A ceramic substrate was obtained by the same process as in Example except that the polyester type plasticizer was not used.

The performance of the ceramic substrates of Examples and Comparative Examples is as shown in Table 1.

[0010]

[Table 1]

[0011]

The present invention is constructed as described above.
With the ceramic substrate having the structure described in the claims, it was confirmed that the present invention is excellent because a ceramic substrate having a good elongation rate and few cracks was obtained.

Claims (2)

[Claims] 1. A ceramic substrate characterized in that a polyester type plasticizer and a binder are added to, mixed with, and kneaded with a ceramic powder, and then formed into a sheet and then fired. 2. The ceramic substrate according to claim 1, wherein the amount of the polyester type plasticizer is 0.5 to 4 parts by weight with respect to 100 parts by weight of the ceramic powder.