JPH0455841B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a green sheet for ceramic substrates, and particularly to an apparatus for manufacturing the green sheet.

(b) Background of the technology Printed wiring boards made of synthetic resin are the mainstream substrates on which semiconductor devices and other circuit components are mounted, but as the mounting density increases, the heat resistance of printed wiring boards Heat dissipation and heat dissipation became a problem, and ceramic circuit boards based on ceramics, which are excellent in this respect, have come into use.

However, in the case of ceramic circuit boards as well as in the case of printed wiring boards, there is a demand for multilayer conductor layers, and this has entered the realm of practical use.

In the production of multilayer ceramic circuit boards, normally a ceramic green sheet is first produced, cut into a predetermined size, printed with wiring, laminated, and fired. The uniformity of the density of the green sheet is important as it affects the shrinkage rate.

(c) Prior art and problems Figure 1 shows an example of a conventional green sheet manufacturing device, where 1 is a carrier film, 2 is a stand,
3 is a doctor blade, 4 is an undried green sheet, 5 is a green sheet, and 6 is a dryer.

The manufacturing apparatus shown in the figure employs the doctor blade method, and the manufacturing process of the green sheet is as follows.

When the carrier film 1 on which the green sheet is placed is sliding on the table 2 and moving from right to left in the figure, the doctor blade 3 passes the slurry (ceramic substrate material powder and binder) that is the material of the green sheet 5. and a solvent) are continuously placed at a constant thickness to form an undried green sheet 4. The undried green sheet 4, which moves along with the movement of the carrier film 1, dries while passing under the dryer and becomes a green sheet 5, completing its production.

In this manufacturing method, when the slurry comes out from the doctor blade 3, the dispersion of the mixture within the slurry, that is, within the undried green sheets 4, is not necessarily uniform. Green sheet 5 obtained by drying in
has the disadvantage that the density deviation becomes large due to the influence of the dispersion.

(d) Object of the Invention In view of the above-mentioned conventional drawbacks, an object of the present invention is to provide a green sheet manufacturing apparatus in which density deviation of the green sheet is reduced.

(e) Structure of the Invention The above object has a first table on which a doctor blade is placed, and a second table on which a vibrator is placed, and the first table and the second table have a first table on which a doctor blade is placed and a second table on which a vibrator is placed. A green sheet manufacturing device in which tables are arranged with intervals,
A green sheet that vibrates via the carrier film by the vibrator to an undried green sheet moving on the carrier film from the distance between the doctor blade and the first stand to the second stand. This is achieved by sheet manufacturing equipment. This is because by applying vibration before drying, the dispersion can be made uniform, and by using a carrier film, it is easy to apply vibration to the entire surface of the undried green sheet.

(f) Embodiment of the Invention An embodiment of the present invention will be described below with reference to the drawings. The same reference numerals indicate the same objects throughout the figures.

FIG. 2 is a diagram showing an example of a green sheet manufacturing apparatus constructed according to the present invention, in which 2a and 2b are stands, 5
a indicates a green sheet, 7 indicates a glass substrate, 8 indicates a vibrator, and 9 indicates an oscillator.

The manufacturing apparatus of this embodiment is an apparatus having means for applying vibration from the carrier film 1 to the moving undried green sheet 4 in the manufacturing apparatus shown in FIG.

A glass substrate 7 and a vibrator 8 are closely arranged on the top surface of the table 2a, and the carrier film 1 is slid on the top surface of the glass substrate 7 and the vibrator 8, and the vibrator is driven by an oscillator 9. 8 is transmitted through the glass substrate 7 as well, the carrier film 1 vibrates, and the undried green sheet 4
It is designed to give vibration to the entire surface of the In addition,
The stand 2b supporting the carrier film 1 under the doctor blade 3 is independent from the stand 2b so as not to vibrate.

By using the manufacturing apparatus of this example, borosilicate glass powder (particle size: approximately 40 μm) was used as a ceramic substrate material.
and alumina powder (particle size: approx. 5 μm) in a weight ratio of 1:1.
100, polyvinyl butyral as a binder and methyl ethyl ketone as a solvent were added at weight ratios of 7 and 80, respectively, and mixed by ball milling to produce slurry. This was placed on the carrier film 1 with a thickness of about 0.3 mm using a doctor blade 3, and the frequency of the vibrator 8 was set to 30 KHz to obtain a green sheet 5a with a thickness of about 0.2 mm.

As shown in Table 1, the density uniformity of the green sheet 5a obtained using this apparatus is extremely superior to that of the green sheet 5 obtained using a conventional apparatus. Moreover, the surface smoothness was also excellent.

Table 1 Density deviation (%) of green sheet Production apparatus of the present invention: 0.2 Conventional production apparatus: 0.7 Note that a liquid such as glycerin is interposed between the carrier film 1 and the glass substrate 7/oscillator 8. Then, the vibration of the carrier film 1 becomes even more effective.

The present manufacturing apparatus described above can be easily applied to mass production, and can be expected to produce green sheets with little density deviation.

(g) Effects of the invention As explained above, according to the configuration according to the present invention, the density deviation of the green sheet is reduced,
Moreover, it is possible to provide a green sheet manufacturing apparatus that can be easily applied to mass production, and has the effect of making it possible to manufacture multilayer ceramic circuit boards of excellent quality.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a conventional green sheet manufacturing apparatus, and FIG. 2 is a diagram showing an example of a green sheet manufacturing apparatus configured according to the present invention. In the drawings, 1 is a carrier film, 2, 2
a and 2b are stands, 3 is a doctor blade, 4 is an undried green sheet, 5 and 5a are green sheets,
6 is a dryer, 7 is a glass substrate, 8 is a vibrator, and 9 is an oscillator.

Claims (1)

[Scope of Claims] 1. It has a first table on which a doctor blade is placed and a second table on which a vibrator is placed, and the first table and the second table are separated from each other. A green sheet manufacturing apparatus is provided with a green sheet manufacturing apparatus arranged with a . A green sheet manufacturing apparatus characterized in that the vibrator applies vibration via the carrier film.