JP2000012986A - Ceramic substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent crackings, chippings, etc., of a ceramic substrate, when the substrate is positioned by chamfering the corner sections of the substrate respectively formed of the broad upper and lower surfaces and narrow side faces of the substrate. SOLUTION: A planar ceramic substrate 1 has a broad upper surface 3 on which splitting grooves 2 are formed, a broad lower surface 4, narrow side faces 5 and 6, and corner sections 7 and 8 respectively formed of the upper and lower surfaces 3 and 4 and side faces 5 and 6. The corner sections 7 and 8 are chamfered to have smooth circular-arcuate R faces, linear C faces, etc. The R and C faces are formed, by pressing the corner sections to a die, when a ceramic green sheet is cut into a prescribed outside dimension with the die. The chamfering sizes of the corner sections are set 1/2 or smaller than the thickness of the substrate 1, but 0.01 mm or larger. The chamfered ceramic substrate can be positioned accurately, when the substrate is used as a hybrid IC board, a substrate for mounting electronic parts, etc., because the used positioning mechanism can operate smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate used for manufacturing electronic components such as chip resistors, hybrid ICs, laminated circuits, and the like.

[0002]

2. Description of the Related Art In recent years, chip resistors, hybrid I
With the miniaturization of electronic devices, the shapes of C, laminated circuits, and the like have been reduced in size, thickness, and precision. Therefore, in the case of a ceramic substrate, a plurality of dividing grooves
A plurality of units are formed on the same sheet by being formed sideways, and are made smaller, thinner, more precise, and the like. In addition, it is necessary to pay attention to the positioning in the process of printing a circuit such as a conductor, a resistor, and a dielectric on a ceramic substrate or a process of mounting an electronic component or the like on a ceramic substrate.

[0003]

However, in the process of manufacturing a ceramic substrate, a ceramic substrate obtained by cutting and firing a green sheet into a sheet shape by a die press or a ceramic substrate cut out by a laser is used. In the step of printing on the ceramic substrate, the step of mounting electronic components, and the like, when the ceramic substrate is positioned by the positioning mechanism, cracking, chipping, or the like of the ceramic substrate occurs on the side surface of the ceramic substrate, resulting in poor positioning, In some cases, there may be problems such as a transportation error due to the shards, and shards of the ceramic substrate adhering to the ceramic substrate.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to a ceramic substrate fired in a flat plate shape, wherein corners where the upper and / or lower surfaces of the ceramic substrate intersect with the narrow side surfaces of the ceramic substrate are chamfered. Accordingly, it is an object of the present invention to provide a ceramic substrate which solves the problem without cracking, chipping or the like of the ceramic substrate when the ceramic substrate is positioned by the positioning mechanism.

Hereinafter, a ceramic substrate according to the present invention will be described in detail with reference to examples.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a ceramic substrate according to the present invention will be described in detail with reference to the accompanying drawings. The ceramic substrate according to the present invention is not limited to the following embodiments.

FIGS. 1 (a), 1 (b) and 1 (c)
1 shows an embodiment of a ceramic substrate according to the present invention, 1 is a ceramic substrate, 2 is a dividing groove (generally a plurality of vertical and horizontal dividing grooves are formed),
Reference numerals 3 and 4 denote wide-area upper and lower surfaces of the flat ceramic substrate, 5 and 6 denote narrow-area side surfaces of the flat ceramic substrate, and 7 and 8 denote an upper surface 3 or lower surface 4 and a side surface 5 or side surface. The corners 7 and 8 are chamfered at the corners 7 and 8 such as a gentle arc-shaped R surface and a straight C surface.

A ceramic green sheet was prepared by a conventionally well-known doctor blade method comprising aluminum oxide as a main component, kneading, coating and drying. A plurality of vertical division grooves and horizontal division grooves were formed in the ceramic green sheet using a mold according to a conventional technique, and a ceramic green sheet for chip resistors cut to predetermined external dimensions was prepared.

As an example of a method for forming a chamfer at a corner, when the ceramic green sheet is cut off to a predetermined outer dimension by a mold, the corner is pressed by the mold to form an R surface,
A C-plane can be formed. As described above, when the corners are pressed by the mold, the ceramic green sheet may slightly rise, and therefore it is preferable that the ceramic green sheet is a dummy that is not a final product.

[0010] The ceramic green sheet for chip resistors cut into predetermined external dimensions was fired, straightened, and the like by a conventional technique to produce a flat ceramic substrate for chip resistors.

The ceramic substrate not chamfered by the mold has corners 7 and 8 which are almost right angles. As an example of a method for chamfering the corners, an end face of the ceramic substrate fired in a flat plate shape is used. Grind. As a method of polishing the end face, a method of chamfering by spraying ceramic powder on a corner portion, which is an end face of the ceramic substrate, and a method of polishing the corner portion, which is an end face of the ceramic substrate, to another structure (abrasive material by rotating an abrasive material). This is a method of chamfering by contact polishing with an object (reciprocating / vibrating).

In the present embodiment, an abrasive is constantly supplied to the rotating body, and is passed through the ceramic substrate for chip resistors having a thickness of 0.5 mm, and the corners are slightly rounded to an average of 0.1 mm.
mm C-plane was formed.

The chamfer dimension of the corner is preferably not more than 1/2 of the thickness of the ceramic substrate and not less than 0.01 mm (R face / C face). More preferably, the radius of curvature is from 0.05 to 1/2 the thickness of the ceramic substrate on the R-plane, or from 0.05 to 1/2 the thickness of the ceramic substrate on the C-plane.

When a thick film printer was used to print each of the ceramic substrate of the present embodiment, which was chamfered at the corners, and the conventional ceramic substrate, 1,000 sheets each, the cracks of the ceramic substrate were zero in the product of the present embodiment. On the other hand, the number of the conventional product was two, and the number of the ceramic substrate was zero in the product of the present example, whereas the number of the conventional product was 72 in the product of the present example.

The ceramic substrate according to the present invention is useful for a substrate for a hybrid IC, a substrate for a chip resistor, a substrate for mounting electronic components, a substrate for a laminated circuit, etc., and is useful because the positioning mechanism operates smoothly.

[0016]

The ceramic substrate according to the present invention is chamfered at the corners intersecting the upper surface and / or the lower surface and the side surfaces, so that the ceramic substrate can be used for positioning by a positioning mechanism such as a printing machine or a mounting machine. Since there is no occurrence of cracks, chips, etc., there are excellent effects such as accurate positioning, no transport error due to fragments, and no adhesion of fragments.

[0017]

[Brief description of the drawings]

FIG. 1 shows an embodiment of a ceramic substrate according to the present invention. (A) is a perspective view of a ceramic substrate fired in a flat plate shape and having a plurality of vertical and horizontal dividing grooves. (B),
(C) shows KK 'of (a) having a C-plane and an R-plane at the corners.
It is sectional drawing.

[0018]

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic substrate 2 Dividing groove 3 Upper surface 4 Lower surface 5, 6 Side surface 7, 8 Corner

Claims (1)

[Claims] 1. A ceramic substrate fired in a flat plate shape, wherein a corner portion where an upper surface and / or a lower surface of a wide area of the ceramic substrate and a side surface of a narrow area of the ceramic substrate intersect is chamfered. Ceramic substrate.