JPH0563365A - Structure of sintered multilayer board - Google Patents

Abstract

PURPOSE:To obtain a sintered multilayered board excellent in dimensional precision wherein, even when large difference exists in the pattern density of printed circuits formed in inner layers, irregularities in the degree of shrinkage is eliminated. CONSTITUTION:At the part where the density of a printed circuit 13 of a board 11 is small, a dummy pattern 14 wherein the same material as printed circuit forming material is used is arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a sintered multi-layer substrate for forming a hybrid integrated circuit or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a plurality of substrates 2 and 2 provided with a predetermined printed circuit 1 on a hybrid integrated circuit or the like.
A multilayer substrate 3 is used which is obtained by stacking and sintering. As the material of the substrate 2, an alumina substrate that is fired at a high temperature, a ceramic substrate that is fired at a low temperature, or the like is used.

Among these, low temperature firing type substrates, for example, ceramic substrates such as green sheets, have the advantage that the shrinkage rate after baking is more stable than high temperature firing type substrates.

[0004]

However, there is a large difference in the pattern densities of the printed circuits 1 formed on the inner layer of the substrate. For example, a portion where the pattern is not formed or a pattern is formed like the portion A in FIG. However, if there is a rough portion, the shrinkage ratio at the time of baking may vary between the portion and the portion where a large number of patterns are formed, and the dimensional accuracy may be impaired, resulting in a defective product. It was

Therefore, an object of the present invention is to provide a structure capable of obtaining a sintered multilayer substrate excellent in dimensional accuracy by eliminating the above-mentioned variation in shrinkage ratio.

[0006]

In order to achieve the above object, the structure of a sintered multilayer substrate of the present invention is a multilayer substrate obtained by stacking and sintering a plurality of substrates having a predetermined printed circuit on the surface thereof. It is characterized in that a discard pattern made of the same material as the printed circuit forming material is provided in a portion of the substrate where the printed circuit has a rough pattern density.

[0007]

[Operation] According to the above configuration, it is possible to average the pattern density on the substrate surface and eliminate variations in shrinkage rate during baking.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to an embodiment shown in FIGS.

This multi-layer substrate 11 is formed by forming a predetermined printed circuit 13 on the surface of each substrate 12, 12 in the same procedure as in the conventional method, stacking the printed circuits 13 and baking them while pressure bonding.

A discard pattern 14 as a dummy circuit is provided on a portion of each substrate 12 where the circuit pattern is not formed, or on a rough portion where the circuit pattern is formed. The discard pattern 14 is formed by printing the pattern of the printed circuit 13 simultaneously with the same material as that of the printed circuit 13.

The position, density, etc. of the discard pattern 14 can be appropriately set according to the state of the printed circuit 13 provided on the substrate 12. That is, the discard pattern 14
Is preferably set so that the pattern is evenly distributed on the substrate 12, but the position, density, thickness, direction, etc. are set so that the dimensional error due to the variation of the shrinkage ratio falls within a predetermined range. Just do it.

As described above, by providing the discard pattern 14 in the portion of the printed circuit 13 of the substrate 12 where the pattern density is rough, the shrinkage rate of the substrate 12 during firing can be made substantially constant, and the shrinkage during firing can be reduced. The dimensional accuracy can be improved by reducing the variation in the rate.

When the pattern densities of the substrates to be laminated are greatly different, the other substrate is provided with a discard pattern so as to correspond to the pattern density of the substrate on which the pattern is most densely formed. The pattern density of each substrate to be sintered can be averaged to prevent variation in shrinkage ratio between the substrates.

[0014]

As described above, according to the present invention,
By averaging the pattern density on the substrate surface, it is possible to reduce the variation in shrinkage rate during baking, so that it is possible to obtain a sintered multilayer substrate with excellent dimensional accuracy, and to improve the manufacturing cost due to improved yield. Reduction can be achieved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sintered multilayer substrate showing an embodiment of the present invention.

FIG. 2 is likewise a plan view of the substrate surface.

FIG. 3 is a sectional view showing an example of a conventional sintered multilayer substrate.

[Explanation of symbols]

11 ... Multilayer substrate 12 ... Substrate 13 ... Printed circuit
14 ... Discard pattern

Claims (1)

[Claims] 1. A multilayer substrate obtained by laminating and sintering a plurality of substrates each having a predetermined printed circuit on the surface thereof, the same material as the printed circuit forming material being provided in a portion where the pattern density of the printed circuit of the substrate is rough. A structure of a sintered multi-layer substrate, characterized by being provided with a discard pattern using.