JPH0242797A - Manufacturing method of multilayer ceramic wiring board - 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] [Summary] The purpose of this method is to form a high-density, fine pattern on the green sheet with good quality, and to produce a smooth surface. After printing a pattern made of conductive paste on a transfer film that is entirely flexible, a green sheet is laminated on the transfer film on which the pattern has been printed, the pattern is transferred to the green sheet, and then the pattern is transferred to the green sheet. It consists of the steps of peeling off the transfer film, stacking a plurality of green sheets with the pattern transferred thereon, and firing them.

(Industrial Application Field) The present invention relates to a method for manufacturing a multilayer ceramic wiring board formed by laminating green sheets.

When forming a pattern by screen printing conductive paste on a green sheet, since the green sheet is porous, the solvent in the conductive paste is absorbed by the green sheet and the pattern is not leveled, resulting in mesh marks from screen printing. remains on the pattern surface and becomes uneven, and when pressure is applied to the green sheets during lamination, the convex portions collapse and spread laterally, making the pattern width uneven. Therefore, it is difficult to form patterns on the green sheets without unevenness. There is a need for a method of manufacturing a multilayer ceramic wiring board that can have a high-density, fine pattern on the inner layer.

[Prior Art] Conventionally, a method for producing a multilayer ceramic wiring board is to screen print a pattern 2 directly on the upper surface of a green sheet 3, stack a plurality of green sheets 3, and then fire the green sheets, as shown in FIG. The lamination method was commonly used.

[Problem to be solved by the invention] However, in the conventional green sheet lamination method,
), place pattern 2 directly on green sheet 3.
is screen printed, but since the green sheet 3 is a porous sheet made by drying and forming a slurry in which a ceramic material is dispersed, the solvent of the conductive paste that forms the pattern 2 is absorbed by the green sheet 3, and the leveling of the pattern 2 is affected. If the process is not carried out sufficiently, mesh marks from screen printing remain, and the surface of the formed pattern 2 becomes uneven.

When a plurality of green sheets 3 having such a pattern 2 are stacked and pressure is applied, the convex portions of the pattern are crushed and spread laterally, as shown in FIG. 4(b), and the width of the pattern is reduced. It has been difficult to form fine patterns with high density because of the non-uniformity. The present invention has been made to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a method for manufacturing a multilayer ceramic wiring board that can form a high-density, fine pattern on a green sheet with good quality. .

[Means for Solving the Problems] The present invention will be explained based on FIGS. 1 and 3 corresponding to embodiments. First, a pattern 2 made of a conductive paste is formed on a transfer film l having a smooth surface and a flexible whole. When printed by screen printing, the surface of the transfer film 1 is smooth and does not absorb the solvent in the conductive paste, so the pattern 2 is sufficiently leveled and a high quality pattern 2 is formed. Next, by laminating the green sheet 3 on the transfer film 1 on which the pattern 2 is printed, the pattern 2 is transferred from the transfer film 1 onto the green sheet 3. After the pattern 2 is transferred, when the transfer film 1 is peeled off, a high-quality pattern 2 with a smooth and leveled surface is transferred and formed on the green sheet 3, and a plurality of such green sheets 3 are laminated. Even if pressure is applied to prevent the pattern from spreading unevenly. By firing the green sheets 3 laminated in this manner, a multilayer ceramic wiring board having a high-quality pattern on the inner layer can be manufactured.

[Effect]

Through the above steps, the present invention first transfers the pattern 2 to a transfer film 1 which has a smooth surface and does not absorb the solvent of the conductive paste.
By printing on top, it is possible to form a leveled pattern 2 with a uniform thickness.In this state, the green sheet 3 is laminated on the transfer film 1 and the pattern 2 is transferred. To manufacture a multilayer ceramic wiring board with a high-density and fine pattern as an inner layer, since a high-quality pattern 2 with no unevenness is formed and the pattern 2 is not crushed to an uneven width when the green sheets 3 are laminated. Can be done.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. First, as shown in FIG. 1, a pattern 2 made of conductive paste is formed on a transfer film 1 by screen printing. Since the pattern 2 does not absorb solvent, the pattern 2 is formed by screen printing on the transfer film 1 and then leveling it to a uniform thickness. Next, as shown in FIG. 2, a green sheet 3 is laminated on the surface of the transfer film 1 on which the pattern 2 is printed.

The green sheet 3 is a porous sheet formed by drying a slurry in which a ceramic material is dispersed, and the transfer film 1 has a high-quality pattern 2 printed on it in advance.
Since the green sheet 3 is laminated on top of the green sheet 3, unlike when printing the pattern 2 directly on the green sheet 3, the solvent of the conductive paste is not absorbed into the green sheet 3 and causes unevenness, which improves quality. A good pattern 2 is directly layered on the green sheet 3, and when the transfer film 1 is peeled off as shown by the two-dot chain line in FIG. 2, a pattern 2 with a smooth surface and good quality can be formed on the green sheet 3. . Next, when a plurality of green sheets 3 with the pattern 3 transferred in this way are stacked, the pattern 3 is subjected to pressure, but since the pattern 3 is leveled without unevenness, it does not spread horizontally unevenly, and the pattern 3 is not spread unevenly. By firing the green sheet 3 shown in FIG.
And a uniform and accurate pattern 3 as shown in (b)
It is possible to manufacture a multilayer ceramic wiring board with an inner layer of

[Effects of the Invention] As is clear from the above explanation, according to the method for manufacturing a multilayer ceramic wiring board according to the present invention, a high-quality pattern can be formed with high precision. It is possible to manufacture a multilayer ceramic wiring board.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the first step of the present invention, FIG. 2 is a sectional view showing the second step of the present invention, and FIG. 3(a) is a sectional view showing a part of the laminated green sheets. , Figure 3(b)
is a plan view of FIG. 3(a), FIG. 4(a) is a sectional view showing one process of the conventional example, and FIG.
b) is a front view of a conventional multilayer ceramic wiring board. In the figure, 1 is a transfer film, 2 is a pattern, and 3 is a green sheet.

Claims (1)

[Claims] After printing a pattern (2) made of conductive paste on a transfer film (1) whose surface is smooth and entirely flexible,
The transfer film (on which the pattern (2) is printed)
1) Lay a green sheet (3) on top and transfer the pattern (2) to the green sheet (3), then peel off the transfer film (1) and remove the green sheet with the pattern (2) transferred thereto. A method for producing a multilayer ceramic wiring board by laminating and firing a plurality of sheets (3).