JP2003297616A - Ceramic substrate for multiple-chip resistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic substrate for multiple-chip resistor, that is provided with longitudinal and transverse dividing grooves and through-holes which are formed at regular intervals on either the longitudinal or the transverse dividing grooves, is divided into a product section partitioned by the outermost longitudinal and transverse dividing grooves and a dummy section between the outermost longitudinal and transverse dividing grooves and the outer periphery of the substrate, and is reduced in the occurrence of defective products by stabilizing the dimensions the and shapes of the outermost through-holes. <P>SOLUTION: In the dummy section 6a including parts of the through-holes 5a formed on the outermost dividing grooves 2a, a plurality of dummy through- holes 7 is formed at intervals equal to those of the through-holes 5a formed on the dividing grooves 2a. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate for a multiple chip resistor used for forming a multiple chip resistor made of ceramic.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing a general multiple chip resistor. This multiple chip resistor 10 is provided with a resistor film 13 between opposed recesses 12 on a long ceramic substrate 11 having both sides formed to be uneven, and each resistor film 13 has both ends thereof. Of the protective film 1 while being electrically connected to the end face electrode films 15 adhered to the concave portions 12 of the respective
4 was to be covered.

Further, in order to form such a multiple chip resistor 10, vertical and horizontal dividing grooves 32 and 3 as shown in FIG.
3 and, for example, a plurality of through holes 35 formed at equal intervals on the horizontal dividing groove 32, and the region partitioned by the vertical and horizontal dividing grooves 32a, 33a located at the outermost side is the product portion 34, the outermost portion. The region from the vertical and horizontal dividing grooves 32a and 33a located at the outer side to the outer sides 31a and 31b of the ceramic substrate 31 is defined as the dummy portion 3
6, the ceramic substrate 31 for multiple chip resistors is used. First, after the end face electrode film 15 is printed and baked on the inner wall surface of the through hole 35 of the ceramic substrate 31 and around the opening, one main surface of the ceramic substrate 31 is printed. Resistor film 13 on the surface side
Is printed and baked, and then the resistance value of the resistor film 13 is set by laser trimming. Then, the protective film 14 is printed and baked on the resistor film 13, and then the lateral dividing groove 3 is formed.
After performing the primary break along 2 and the secondary break along the vertical dividing groove 33, the multiple chip resistor 10 as shown in FIG. 4 was manufactured.

In order to manufacture the ceramic substrate 31 for multiple chip resistors, first, a ceramic green sheet is prepared and a plurality of holes 40 are formed as shown in FIG. 6 (a).
After forming a vertical and horizontal dividing groove 32, 33 by pressing a metal mold 41 having a V-shaped cross-section on the surface of the ceramic green sheet 39 mounted on the lower punch 40 having a, As shown in FIG. 6B, the ceramic green sheet 39 is punched at a predetermined position on the divided groove 32 in the lateral direction with a punching pin 42 having a cylindrical tip surface to form a plurality of through holes 35, and then a ceramic green sheet 39. Was manufactured by firing (Japanese Patent Laid-Open No. 10-15682).
(See Japanese Patent Publication No. 1).

[0005]

By the way, when the through hole 35 is punched on the dividing groove 32 by the punching pin 42,
A tensile stress is generated in the ceramic green sheet 39 in the direction in which the through hole 35 expands, but the tensile stress generated in the extending direction of the dividing groove 32 is high due to the formation of the dividing groove 32. There is almost no influence on the shape of the holes 35, and the tensile stresses generated in the vertical direction with respect to the division grooves 32 are mutually different due to the stress generated when the through holes 35 are formed on the adjacent division grooves 35. Since they work so as to cancel each other, the shape of the through hole 35 is hardly affected.

However, the outermost dividing groove 32 is provided.
Since the tensile stress does not act on the through hole 35a on the a side from the dummy portion side on which a part of the through hole 35a is applied, only the shape of the through hole 35a formed on the outermost dividing groove 32a is shown in FIG. There was a problem that it was transformed into such an elliptical shape.

Therefore, when the end face electrode film 15 is formed thereafter, the through hole 35 on the outermost dividing groove 32a is formed.
However, the end face electrode film 15 having a uniform film thickness cannot be formed, and in a severe case, the end face electrode film 15 becomes a defective product, so that the yield cannot be improved.

[0008]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a dividing groove vertically and horizontally formed on at least one main surface of a ceramic substrate and a dividing groove on either the vertical direction or the horizontal direction. The product part is an area partitioned by vertical and horizontal dividing grooves located at the outermost side, and a region from the outermost vertical and horizontal dividing grooves to the outer edge of the ceramic substrate. In a ceramic substrate for multiple chip resistors having a dummy portion, a plurality of through holes are formed outside the outermost dividing groove in which the through hole is formed, at intervals equal to those of the through hole on the outermost dividing groove. It is characterized in that a dummy hole is provided.

The shortest distance between the dummy hole and the through hole on the outermost dividing groove is preferably equal to the distance between the through holes formed on the adjacent dividing grooves of the product portion.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

FIG. 1 is a plan view showing an example of a ceramic substrate for multiple chip resistors according to the present invention.

This ceramic substrate 1 for multiple chip resistors
Has a horizontal dividing groove 2 and a vertical dividing groove 3 on at least one main surface of the ceramic substrate 1, and has a plurality of through holes 5 formed on the horizontal dividing groove 2 at equal intervals. Prepare,
The area partitioned by the outermost vertical and horizontal dividing grooves 2a and 3a is the product portion 4, and the outermost vertical and horizontal dividing grooves 2a and 3a.
To the outer edges 1a and 1b of the ceramic substrate 1 are used as the dummy portion 6.

The ceramic forming the ceramic substrate 1 for multiple chip resistors is not particularly limited, and a ceramic sintered body containing alumina, zirconia, mullite, silicon nitride, aluminum nitride or the like as a main component is used. it can. The sectional shape of each of the dividing grooves 2 and 3 is V
The through hole 5 has a circular shape in plan view.

In the ceramic substrate 1 for multiple chip resistors of the present invention, the lateral dividing groove 2a is located outside the outermost dividing groove 2a in which the through hole 5a is formed, that is, the outermost dividing groove 2a. A plurality of dummy holes 7 are formed in the dummy portion 6a, which covers a part of the upper through hole 5a, at intervals equal to those of the through hole 5a on the outermost dividing groove 2a.

That is, in order to manufacture the ceramic substrate 1 for multiple chip resistors shown in FIG. 1, first, a ceramic green sheet is prepared and, as shown in FIG. 2 (a), a lower punch having a plurality of holes 20a. After the die 21 having a V-shaped cross-section is pressed against the surface of the ceramic green sheet 9 placed on 20 to form vertical and horizontal dividing grooves, as shown in FIG. A punching pin 2 having a cylindrical shape with a flat tip surface at a predetermined position on the lateral dividing groove 2.
2 is punched out to form a plurality of through holes 5,
At this time, the punching pin 23 is equivalent to the through hole 5a on the outermost dividing groove 2a by the punching pin 23 even on a part of the through hole 5a formed on the outermost lateral dividing groove 2a. By punching the plurality of dummy portions 7 at intervals of, the tensile stress in the direction perpendicular to the dividing groove 2a can be applied from both sides to the through hole 5a on the dividing groove 2a located on the outermost side. The deformation of the through hole 5a can be prevented, and as shown in FIG. 3, the planar shape can be made circular like the other through holes 5.

Therefore, by firing the ceramic green sheet 9 having the division grooves 2 and 3 and the through holes 5 at a predetermined temperature, the dimensional accuracy of all the through holes 5 formed in the product portion 4 is stabilized. Therefore, it is possible to prevent film formation defects during the formation of the end face electrode film and eliminate the generation of defective products, so that the yield can be improved.

In order to achieve such an effect, the shortest distance L between the dummy hole 7 formed in the dummy portion 6a and the through hole 5a formed on the outermost lateral dividing groove 2a is: It is preferable that the distance W between the through holes 5 formed on the adjacent division grooves 2 of the product portion 4 is close to, and preferably equal to each other.

This is because if the shortest distance L between the dummy hole 7 and the through hole 5a becomes larger or smaller than the interval W between the through holes 5 formed on the adjacent dividing grooves 2 of the product portion 4, it becomes too small. When punching the through hole 5a on the outermost lateral dividing groove 2a by the punching pin 22, there is a difference between the tensile stress acting from the product part side and the tensile stress acting from the dummy part side. , The dimensions of the through holes 5a formed on the outermost lateral dividing grooves 2a cannot be stabilized, and thus the shortest distance between the dummy holes 7 and the through holes 5a. By setting L to be equal to the interval W between the through holes 5 formed on the adjacent division grooves 2 of the product portion 4, the tensile stress acting from the product portion side and the tensile stress acting from the dummy portion side are large. Equality and mutual It is possible to offset the tensile stress, the dimensions of the through holes 5a to be formed in the lateral direction of the dividing groove 2a on which is located outermost can be stabilized.

In the present invention, the shortest distance L between the dummy hole 7 and the through hole 5a is determined by the adjacent division grooves 2 of the product portion 4.
The same as the distance W between the through holes 5 formed above means that
When the distance W between the through holes 5 is 1, the shortest distance L is the distance W.
To 0.8 to 1.2.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and for example, the planar shape of the through hole 5 is not limited to the circular shape. The shape may be an ellipse, a rhombus, a quadrangle such as a square, or a dummy dividing groove may be formed in the dummy portion 6 in consideration of the dividing property.

As described above, it goes without saying that the invention can be applied to the modified and modified ones without departing from the scope of the invention.

[0022]

EXAMPLES Here, 20 ceramic chip substrates for multiple chip resistors 1 of the present invention shown in FIG. 1 and 20 ceramic substrate chips for conventional multiple chip resistors shown in FIG.
An experiment was conducted to compare the dimensional accuracy of the through holes 5a and 35a formed on the outermost lateral dividing grooves 2a and 32a.

Further, in the ceramic substrate 1 for multiple chip resistors of the present invention, the shortest distance from the through hole 5a formed on the outermost lateral dividing groove 2a to the dummy hole 7 formed on the dummy portion 6a. The same experiment was conducted by preparing those having different distances L.

Each of the ceramic substrates 1 and 31 for multiple chip resistors used in this experiment was made of alumina ceramics having an alumina content of 96% by weight, and the outer side dimension was 60.0 × 51.2 mm and the plate thickness was Was 0.37 mm.

The multiple chip resistors taken out by division are four in series, and the outside dimension is 2.0 mm.
× 1.0 mm, and the vertical and horizontal dividing grooves 2, 3, 3 are formed so that 46 rows are formed in the long side direction and 16 rows are formed in the short side direction of the plate-shaped body.
2 and 33 are formed, and lateral division grooves 2 and 32 are formed.
A total of 3008 through holes 5 and 35 are formed on the upper surface of the conventional ceramic substrate 31 for a multiple chip resistor.
Was produced.

Further, in the ceramic substrate 1 for multiple chip resistors of the present invention, the dummy portion 6a to which a part of the through hole 5a formed on the outermost lateral dividing groove 2a is applied, A plurality of dummy holes 7 are formed at the same intervals as the through holes 5a on the outermost divided groove 2a.

However, in both cases, the through holes 5, 35 and the dummy hole 7 have a circular plane shape, and the hole diameter is 0.14 mm.
And

Then, as shown in FIGS. 3 and 7, the through hole 5 on the outermost lateral dividing grooves 2a and 32a is formed.
a, 35a diameter (X) in the extending direction and through hole 5a,
The diameter (Y) in the direction perpendicular to 35a is measured, and the roundness of the through holes 5a and 35a is evaluated by calculating the length difference.

The results are shown in Table 1.

[0030]

[Table 1]

As a result, as can be seen from Table 1, in the conventional ceramic substrate 31 for multiple chip resistors having no dummy hole, the maximum difference in length of the through hole 35a located at the outermost side was 0.028 mm. .

On the other hand, in the ceramic substrate for multiple chip resistors 1 of the present invention, the dummy holes 7 are formed, so that the conventional ceramic substrate for multiple chip resistors 3 is formed.
It can be seen that the difference in length between the outermost through holes 5a can be made smaller than that of No. 1.

When the distance W between the through holes 5 on the adjacent dividing grooves 2 of the product portion 4 is 1, the shortest distance L from the outermost through hole 5a to the dummy hole 7 is 0.8 to 1. The maximum value of the difference in length of the through holes 5a located at the outermost part can be set to 0.01 mm or less by setting to be 0.2, which was particularly excellent.

[0034]

As described above, according to the present invention, the dividing grooves formed in the vertical and horizontal directions on at least one main surface of the ceramic substrate and the equal intervals on the dividing grooves in either the vertical direction or the horizontal direction. It has a plurality of through holes perforated with the product. In the multiple chip resistor ceramic substrate described above, a plurality of dummy holes are provided at the same interval as the through holes on the outermost divided groove in the dummy part where a part of the through hole on the outermost divided groove is applied. By providing the through holes, it is possible to suppress the deformation of the through holes on the outermost dividing grooves and maintain the dimensional accuracy to the same level as that of the other through holes. In particular, by positioning the shortest distance between the dummy hole and the through hole on the outermost dividing groove to be the same as the distance between the through holes formed on the adjacent dividing grooves of the product part, the outermost portion is positioned. The size of the through hole on the dividing groove can be made more stable.

Therefore, if the ceramic substrate for multiple chip resistors is used, it is possible to take out good multiple chip resistors from the product section without generating defective products.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a ceramic substrate for multiple chip resistors according to the present invention.

2A and 2B are cross-sectional views for explaining a manufacturing process of the ceramic substrate for multiple chip resistors of the present invention.

FIG. 3 is an enlarged plan view of a through hole formed on the outermost dividing groove of the ceramic substrate for multiple chip resistors of the present invention.

FIG. 4 is a perspective view showing a general multiple chip resistor.

FIG. 5 is a plan view showing an example of a conventional ceramic substrate for multiple chip resistors.

6A and 6B are cross-sectional views for explaining a manufacturing process of a conventional ceramic substrate for multiple chip resistors.

FIG. 7 is an enlarged plan view of a through hole formed on an outermost division groove of a conventional ceramic substrate for multiple chip resistors.

[Explanation of symbols]

1: Ceramic substrate for multiple chip resistors 2: Lateral dividing groove 2a: Outermost lateral dividing groove 3: Vertical dividing groove 3a: Outermost vertical dividing groove 4: Product Part 5: Through hole 5a: Through hole on the outermost dividing groove 6: Dummy part 6a: Part of the through hole on the outermost dividing groove is applied Dummy part 7: Dummy hole 9: Ceramic green sheet 10 : Multiple chip resistor 11: Ceramic substrate 12: Recessed portion 13: Resistor film 14: Protective film 15: End face electrode film 20: Lower punch 20a: Hole 21: Die 22, 23: Punch punch

Claims (2)

[Claims] 1. A ceramic substrate is provided with dividing grooves formed in at least one main surface in a vertical and horizontal direction, and a plurality of through holes formed in the dividing groove in either the vertical direction or the horizontal direction at equal intervals. In the ceramic board for multiple chip resistors, the area partitioned by the vertical and horizontal dividing grooves located at the outermost is the product section, and the area from the outermost vertical and horizontal dividing grooves to the outer side of the ceramic board is the dummy section. A multiple chip resistor characterized in that a plurality of dummy holes are provided outside the outermost dividing groove in which the through hole is formed, at the same intervals as the through holes on the outermost dividing groove. Ceramic substrate. 2. The shortest distance between the dummy hole and the through hole on the outermost divided groove is equal to the distance between the through holes formed on the adjacent divided grooves of the product portion. The ceramic substrate for multiple chip resistors according to claim 1.