JPH0442865A - How to apply powder for firing ceramic substrates - Google Patents

Abstract

PURPOSE:To extremely uniformly coat a setter with spreading powder for sintering by forming a green sheet containing a spreading powder comprising boron nitride, etc., an organic binder and a plasticizer, placing the green sheet on the setter and subsequently calcining the green sheet. CONSTITUTION:A slurry containing a spreading powder comprising boron nitride powder, etc., and used for calcined ceramic substrates, an organic binder and a plasticizer is formed into a green sheet 4 on a carrier sheet 6. The green sheet 4 is peeled, placed on a setter 7 and calcined, thereby uniformly coating the setter 7 with the spreading powder 5. A green sheet 8 for a ceramic substrate is placed on the spreading powder-coated setter 7 and then calcined.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for applying a coating powder for firing ceramic substrates used in manufacturing ceramic substrates.

2. Description of the Related Art In recent years, with the miniaturization of electronic devices, ceramic multilayer substrates have been widely used as a means of high-density packaging.

Ceramic multilayer boards have traditionally been required to be of high quality and high reliability in order to mount electronic components at high density, and accordingly, the firing powder used when manufacturing ceramic multilayer boards has been required. There has also been a demand for a coating method with high quality and high uniformity.

An example of a method of applying the above-mentioned conventional coating powder for firing a ceramic substrate will be described below with reference to the drawings.

Fig. 2 shows the steps of the conventional method of coating powder for firing ceramic substrates. In the figure, 1 is a setter made of alumina, 2 is a green sheet that becomes a ceramic multilayer board by firing, and 3 is a setter made of alumina. is a baking powder that is mixed with an organic solvent and sprayed on in the form of a mist.

The coating method will be explained below.

When manufacturing a ceramic multilayer substrate, first, a firing powder 3 mixed with an organic solvent is sprayed onto the setter 1 in the form of a mist, and dried at room temperature to evaporate and remove the organic solvent. Next, the green sheet 2 is placed on the baking powder 3 and fired to obtain a ceramic multilayer substrate. In this case, the baking powder 3 is used to prevent the green sheet 2 from being fused to the setter 1.

Problems to be Solved by the Invention However, with the above configuration, it is not possible to evenly and uniformly apply the baking powder 3 onto the setter 1.
There have been problems in that the yield of ceramic multilayer substrates is reduced due to warping or deformation of the ceramic multilayer substrates, and coating variations among the many setters 1 used for firing.

The present invention solves the above-mentioned problems, and aims to provide a method for applying a ceramic substrate firing powder that can form a firing powder with extremely high uniformity on a setter. .

Means for Solving the Problems In order to achieve the above-mentioned objects, the present invention provides a method in which a slurry containing a ceramic substrate firing powder made of boron peroxide powder, an organic binder, and a plasticizer is placed on a carrier sheet. A green sheet is prepared, and then the green sheet is placed on a setter with a screen curtain U and fired, so that the baking powder is evenly and uniformly applied.

Therefore, according to the present invention, a green sheet prepared by mixing ceramic firing powder, an organic binder, and a plasticizer with the above-mentioned configuration is placed on a ceramic plate and fired. Since the bedding powder is distributed evenly and evenly, the bedding powder for ceramic firing is evenly coated and formed on the setter.

EXAMPLE Hereinafter, a method of applying a coating powder for firing a ceramic substrate according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the process of applying powder for firing ceramic substrates in one embodiment of the present invention.
4 is a green sheet prepared by mixing a ceramic firing powder made of boron nitride powder, an organic binder, 1lliJ plasticizer, etc., and 6 is a green sheet in which the organic binder and plasticizer are separated and lost by firing the green sheet 4. This is the remaining powder for firing ceramic substrates.

The method for applying the coating powder 6 for firing ceramic substrates will be described in detail below.

Boron nitride powder, an organic binder, a plasticizer, etc. are mixed together as a ceramic substrate baking powder 5, and after being weighed and kneaded in a ball mill, a green sheet 4 with a thickness of 50 μm is placed on a carrier sheet θ using a doctor blade method.
It is molded, dried and then wound into a roll. Next, the wound green sheet 4 is peeled off from the carrier sheet 6 and then cut into a predetermined size. A green sheet 4 cut into a predetermined size is placed on a seven-piece vine 7 made of a ceramic material such as alumina, and heated to a temperature of 900'c't' to decompose and dissipate the binder. The ceramic substrate firing powder 6 is evenly and uniformly coated on the setter 7 which has been fired in this manner. Next, a ceramic substrate green sheet 8 is placed on the setter 7 to which the ceramic substrate baking powder 6 is evenly applied and is baked at a high temperature to obtain a ceramic substrate.

As described above, according to the present embodiment, by making the ceramic substrate firing powder 6 into a green sheet shape, the ceramic substrate firing powder 6 can be uniformly dispersed within the green sheet 4, so that the powder on the setter 7 This means that the ceramic substrate firing powder 5 can be applied and formed evenly and uniformly over the entire surface.

In this embodiment, the green sheet 4 is formed using a doctor blade method, but the green sheet 4 can also be formed using other methods.

Further, although the firing temperature was set at 900°C in the examples, other temperatures may be used as long as the organic binder and plasticizer can be dissociated and released.

In addition, in the example, the thickness of the green sheet 4 is 60 μm.
green sheet 4 having a thickness other than this.
Similar effects can also be obtained.

Further, in the embodiment, a setter other than alumina was used, but other than alumina, a ceramic setter such as zirconia or mullite can also be used.

Effects of the Invention As is clear from the above examples, the present invention is to prepare a green sheet by mixing a ceramic substrate firing powder, an organic binder, and a plasticizer, and then place it on a setter and fire it. This allows ceramic firing powder to be evenly distributed and coated onto the setter, and is highly effective in preventing warpage and deformation of ceramic substrates and improving yield.

[Brief explanation of drawings]

FIG. 1 is a process diagram for explaining a method of applying a coating powder for firing a ceramic substrate in a simple embodiment of the present invention, and FIG. 2 is a process diagram for explaining a conventional method of applying a coating powder for firing a ceramic substrate. It is. 4... Clean sheet, 6... Ceramic substrate baking powder, 6... Carrier sheet,
7...Name of setter agent Patent attorney Shigetaka Awano and 1 other person [[]

Claims (1)

[Claims] A green sheet is created by forming a slurry containing a ceramic substrate firing powder made of boron nitride powder, an organic binder, and a plasticizer on a carrier sheet, and then the green sheet is peeled off and placed on a setter for firing. A method for applying a ceramic substrate firing powder, characterized in that the ceramic firing powder is evenly applied and formed on a setter by applying the following steps.