JPH0748408B2 - Ceramic substrate for sheet electronic parts - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate for electronic parts used for chip parts and the like used in electronic equipment.

2. Description of the Related Art Generally, as shown in FIG. 5, a chip resistor is provided with a resistor 12 by coating a resistor paste on a ceramic substrate 11 by screen printing or the like and firing it, and connecting it to the resistor 12. And the electrode 13 is provided so as to be formed from the end face to the bottom face of the ceramic substrate 11, and the glass film 14 is provided so as to protect the resistor 12.

Conventionally, a ceramic substrate for electronic parts used in this type of chip resistor or the like has a shape as shown in FIGS. 6 to 8. 6 to 8 show a schematic view of a ceramic substrate for making a chip component, 15 is a ceramic substrate before division, 16 is a vertical dividing groove, and 17 is a horizontal dividing groove. If the surface having the dividing grooves 16 and 17 is used as the surface, the warp of the substrate in the horizontal direction is a valley shape with respect to the surface when viewed from the side, and the warp of the substrate in the vertical direction is also from the side. When viewed, it has a valley shape with respect to the surface. In such a conventional ceramic substrate, since the warp of the substrate has a valley shape and the valley shape of the ceramic substrate progresses as shown in FIG. 13 each time the process is processed and fired, the following drawbacks occur. there were.

FIG. 9 shows a paste state when screen printing is performed in a general chip resistor manufacturing process. Thirteenth
As shown in the figure, since the valley shape of the ceramic substrate 15 is extremely advanced after the first firing, when the resistor and the glass portion are formed by screen printing as shown in FIG. There is a drawback that variations occur from place to place, the yield of resistance value deteriorates, and the total thickness of products varies.

Further, FIG. 10 is a front view of the step of dividing the ceramic substrate after the third firing along the dividing groove 17 in the lateral direction, and 19 is the dividing point 20 and 21 of the ceramic substrate 15 for dividing. It is a jig. At such division points 19, the transverse rupture force for division is concentrated on the division points 19, and after the division, a deformed portion 22 as shown in FIG. There is a drawback that troubles are likely to occur when mounting and mounting. In addition, the moment when the division is performed, the ceramic substrate 15 is slightly bent, and stress is applied to the vertical dividing groove 16, so that the horizontal dividing groove 17 is formed.
At the same time as the division along the line, the division groove 16 in the vertical direction is also divided, resulting in a defect that a division defect as shown in FIG. 12 occurs.

Problems to be Solved by the Invention In order to reduce the printing film thickness variation in such a conventional ceramic substrate, it is necessary to reduce the depth of the dividing groove and reduce the warpage of the ceramic substrate. However, in order to improve the dividability, it is necessary to increase the depth of the dicing groove, but the warp of the ceramic substrate becomes large, and the printed film thickness varies. Has a problem that adversely affects

It is an object of the present invention to stabilize the variation of the printed film thickness of the ceramic substrate and solve the problems of the dividability as described above.

Means for Solving the Problems In order to solve the above problems, the present invention has a dividing groove for dividing the surface vertically and horizontally, and provides a chevron-shaped warp with the dividing groove side upward. It is a thing.

Operation According to this configuration, the resistance of the substrate is flattened and the variation of the printed film thickness is reduced in the resistance, the glass paste printing, and the step of dividing the dividing groove in the horizontal direction by performing the process processing and firing. The value yield can be improved and the variation in the total product thickness can be reduced. Also, in the process of dividing the lateral dividing groove, the dividing point becomes a line, the bending force for dividing can be dispersed, and irregularity does not occur. The bending of the substrate at the time of division is also eliminated, and the stress applied to the vertical division groove is reduced, so that division defects can be reduced.

EXAMPLES Hereinafter, the present invention will be described with reference to the drawings using examples of ceramic substrates for chip resistors.

FIG. 1 shows a ceramic substrate according to an embodiment of the present invention, FIG. 2 shows a warped shape of the ceramic substrate seen from the lateral direction, and FIG. 3 shows a warped shape of the ceramic substrate seen from the vertical direction. There is. That is, according to the present invention, as shown in FIG. 2 and FIG. 3, dividing grooves 2 and 3 are provided on the surface of the ceramic substrate 1, and the warp shape of the ceramic substrate 1 with respect to the surface is made into a mountain shape. . The dimensions are, for example, 30 μm for A in FIG. 2, 15 μm for B and C, and 40 μ for D in FIG.
m, E and F were set to 20 μm.

The warp shape of the ceramic substrate in the horizontal direction corresponds to FIG. 7, and the warp shape of the substrate in the vertical direction corresponds to FIG.

Hereinafter, specific effects when the ceramic substrate of the present invention is used will be described.

Create 1,000 ceramic substrates of the present invention, put into a chip resistor manufacturing line, check the substrate warp shape for each process firing, check the resistance value variation, check the glass film thickness variation, check the split variant occurrence rate, The fraction defective was confirmed.

As shown in FIG. 4, since the substrate warp shape due to the process working and firing became a substantially flat shape, the variation in the resistance value could be σ≈1.5% from what was conventionally σ≈4%. The variation in glass film thickness, which was conventionally σ = 6.8 μm, can be reduced to σ = 3.5 μm. or,
The ratio of occurrence of split variants was 3.2%, which was 1.3% or less, and the split defect rate was 0.8%, which could be reduced to 0.3%.

Effects of the Invention As described above, the ceramic substrate in the present invention is a sheet-shaped ceramic substrate that produces individual electronic components by dividing along the dividing grooves formed in the vertical and horizontal directions. The warp of the ceramic substrate that has occurred can be reduced by providing the warp in the direction opposite to the warp, that is, in the chevron shape with the dividing groove side as the upper side. In addition, it is possible to provide an electronic component with reduced variations in the printed film thickness and uniform electrical characteristics and product film thickness, and an electronic component with a uniform division size that can be divided along a predetermined dividing groove with extremely high precision. It becomes possible to provide.

[Brief description of drawings]

1 is a perspective view showing a ceramic substrate for electronic parts according to an embodiment of the present invention, FIG. 2 is an explanatory view seen from the lateral direction of FIG. 1, and FIG. 3 is seen from the longitudinal direction of FIG. Explanatory diagram, FIG. 4 is an explanatory diagram showing the state of warpage of the same substrate due to process processing firing, FIG. 5 is a sectional view showing a general chip resistor, FIG.
FIG. 7 is a perspective view showing a conventional ceramic substrate, and FIG.
FIG. 8 is a cross-sectional view seen from the lateral direction of the figure, FIG. 8 is a cross-sectional view seen from the longitudinal direction of FIG. 6, and FIG. 9 is an explanatory view showing a printed film thickness state when a conventional ceramic substrate is used. The figure is a front view showing the process of dividing the horizontal dividing groove.
Figure 10 is a perspective view showing the problems that occur when dividing
FIG. 13 is an explanatory diagram showing the state of warpage of a conventional ceramic substrate due to process processing and firing. 1 ... Ceramic substrate, 2, 3 ... Dividing groove.

Claims (1)

[Claims] 1. A ceramic substrate for a sheet-shaped electronic component, characterized in that it has a split groove for vertical and horizontal division on the surface, and is provided with a chevron-shaped warp with the split groove side facing upward.