JPH11186011A - Ceramic board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make dividing property of a ceramic board extremely satisfactory, even when the ceramic board is composed of dielectric which is comparatively fragile, and more surely prevent cracks of the ceramic board at the time of carrying. SOLUTION: In a ceramic board 1, through-holes 2 are formed, and a plurality of first dividing trenches 3 which reach the through-holes 2 and a plurality of second dividing trenches 4 which do not reach the through-holes 2 are formed on a surface. In the first dividing trenches 3, at least the regions in the vicinities of the through-holes 2 are formed shallower than the second dividing trenches 4. The depth of the first dividing trenches 3 is set to be 70-90% of the depth of the second dividing trenches 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate with a divided groove used when manufacturing electronic components such as chip resistors, high-frequency devices, thick-film hybrid integrated circuits, isolators, chip capacitors, etc. by "multi-piece". It is about.

[0002]

2. Description of the Related Art Conventionally, a ceramic substrate having a divided groove has been used to manufacture electronic components such as chip resistors by "multiple-piece".

In such a ceramic substrate, each single chip obtained by the division functions as a base material of an electronic component. For example, a division groove having a certain depth in the vertical and horizontal directions is formed on one main surface of a ceramic green sheet. Are manufactured by firing at a high temperature those provided with a plurality of.

[0004] In order to "multi-piece" electronic components using such a ceramic substrate, first, a conductive paste or the like is applied to one main surface or both surfaces of the ceramic substrate in a predetermined pattern and is baked at a high temperature to form a conductor. A pattern or the like is formed, and thereafter, the ceramic substrate is sequentially divided in a vertical direction and a horizontal direction along a division groove by application of an external force, thereby forming a plurality of single chips.

[0005] The dividing grooves of the ceramic substrate are formed by pressing a mold having a plurality of blades implanted against one main surface of the ceramic green sheet with a predetermined pressing force. The ceramic substrate has a predetermined depth, for example, a thickness of 0.60 m so that the ceramic substrate can be relatively easily divided at the time of the above-mentioned division.
0.20 in the case of m.
They are all equally formed with a depth of mm.

Recently, in order to print an end face only on a part necessary for manufacturing an electronic component, a semi-cylindrical notch is formed in an end face of a single chip 11 obtained by dividing a ceramic substrate as shown in FIG. 12 is provided. In a ceramic substrate for obtaining such a single chip 11, a circular through hole is formed on a part of the dividing groove, and by dividing the ceramic substrate along the dividing groove, an end face of the single chip 11 is formed. The semi-cylindrical notch 12 as described above is provided.

[0007]

However, in this conventional ceramic substrate, since all the dividing grooves are formed at the same depth, of these dividing grooves, one having a through-hole arranged therein and The mechanical strength of that part is significantly different from that of the other parts. That is, the dividing groove of the ceramic substrate is usually formed to a certain depth so that it is not necessary to apply an excessively large external force at the time of division. The mechanical strength of the ceramic substrate becomes extremely low. For this reason, when a large vibration or impact is applied to the ceramic substrate during the transfer of the ceramic substrate or the like, the ceramic substrate is cracked at the divided groove passing over the through hole, and the reliability of the ceramic substrate is greatly reduced. Had disadvantages.

[0008]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and a ceramic substrate of the present invention has a through hole, and has a plurality of first through holes connected to the through hole on one main surface. A ceramic substrate provided with a dividing groove and a plurality of second dividing grooves not communicating with the through holes,
The first dividing groove is characterized in that at least a depth of a region near the through hole is formed shallower than that of the second dividing groove.

Further, the ceramic substrate of the present invention is characterized in that:
The depth of the dividing groove is 70% to 90% of the depth of the second dividing groove.
%.

That is, according to the present invention, the depth of the first divided groove passing over the through-hole is made smaller than the depth of the second divided groove not passing over the through-hole. Appropriate mechanical strength can be given to the portion where the first division groove is provided, and therefore, cracking of the ceramic substrate due to vibration or impact during transportation or the like is effectively prevented, and the reliability of the ceramic substrate is improved. It becomes possible.

Further, since the first dividing groove is formed so as to communicate with the through hole, the ceramic substrate can be accurately divided along the dividing groove. This allows
There is an advantage that chipping hardly occurs at the edge of each single chip obtained by dividing the ceramic substrate, and the yield of electronic components is also improved.

Further, according to the present invention, the depth of the first dividing groove is set to 70% to 90% of the depth of the second dividing groove,
Even when the ceramic substrate is made of a relatively brittle dielectric, the splitting of the ceramic substrate can be made extremely good, and the ceramic substrate can be more reliably prevented from cracking during transportation or the like.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing one embodiment of the ceramic substrate of the present invention, wherein 1 is a ceramic substrate, 2 is a through hole, 3 is a first division groove, and 4 is a second division groove.

The ceramic substrate 1 is made of alumina ceramic, zirconia, mullite, forsterite, M
g-Ca-Ti dielectric, Ba-Mg-W dielectric, B
It is made of a ceramic material such as an a.Ti-based dielectric or a Ba.Nd.Ti-based dielectric, and its thickness is appropriately set according to the application, and is formed in a square shape.

The ceramic substrate 1 has a plurality of through-holes 2 and one of its main surfaces is provided with a plurality of divided grooves 3 and 4 in the vertical and horizontal directions.

The through holes 2 are, for example, arranged in a matrix of nine rows and three rows in the vertical and horizontal directions. These through holes 2 divide the ceramic substrate 1 along the dividing grooves 3 and 4. In this case, a semi-cylindrical or rectangular column-shaped notch is formed on the end face of the obtained single chip.

On the other hand, the plurality of divided grooves 3 and 4 provided on one main surface of the ceramic substrate 1 include a first divided groove 3 communicating with the through hole 2 and a plurality of second divided grooves not communicating with the through hole 2. And 4.

The dividing grooves 3 and 4 apply an external force to the ceramic substrate 1 to divide the ceramic substrate 1 into a plurality of single chips,
Alternatively, when the dummy portion 1a provided on the peripheral portion of the ceramic substrate 1 is cut off, the operation is performed easily and accurately, and each of the dummy portions 1a has a predetermined depth so as to form a V-shaped cross section. It is formed.

The first and second divisional grooves 3 and 4 are formed to have different depths. Specifically, as shown in FIGS. 2A and 2B, the depth D ₁ of the first dividing groove 3 is 70 times the depth D ₂ of the second dividing groove 4.
% To 90%. For example, when the thickness of the ceramic substrate 1 is 0.60 mm and the depth of the second division groove 4 is 0.20 mm, the depth of the first division groove 3 is 0%. .1
It is set within the range of 4 to 0.18 mm.

As described above, the depth D ₁ of the first divided groove 3 passing through the through hole 2 is made smaller than the depth D ₂ of the second divided groove 4 not passing through the through hole 2. In addition, appropriate mechanical strength can be given to the portion of the ceramic substrate 1 where the first division groove 3 is provided. Therefore, cracking of the ceramic substrate 1 due to vibration or impact during transportation or the like is effectively prevented, and the reliability of the ceramic substrate 1 can be improved.

Further, since the first dividing groove 3 communicates with the through hole 2 on one main surface of the ceramic substrate 1, the ceramic substrate 1 can be accurately divided along the dividing groove 3, and each single chip Chipping can be effectively prevented from occurring at the edge of. As a result, the yield of electronic components obtained by dividing the ceramic substrate 1 is greatly improved.

The first divided groove 3 has a depth D ₁ equal to or greater than 70% of a depth D ₂ of the second divided groove 4, so that the ceramic substrate 1 is made of a Mg.Ca.Ti based dielectric. Ba ・ M
g-W dielectric, Ba-Ti dielectric, Ba-Nd-T
Even when the ceramic substrate 1 is made of a relatively brittle dielectric material such as an i-type dielectric, the mechanical strength of the ceramic substrate 1 can be increased to reliably prevent the ceramic substrate 1 from cracking.
Further, by setting the depth D ₁ to 90% or less of the depth D ₂ , there is an advantage that the dividing property of the ceramic substrate 1 is extremely excellent, and the occurrence of chipping can be effectively prevented. Therefore, the depth D ₁ of the first division groove 3 is 7 times the depth D ₂ of the second division groove 4.
It is preferable to set within the range of 0% to 90%.

Further, the dividing grooves 3 and 4 have their angles θ ₁ ,
By setting θ ₂ to 40 ° or more, it is possible to more effectively prevent the occurrence of cracks due to vibration or the like during the transfer of the ceramic substrate 1, and to set the angles θ ₁ , θ ₂ of the dividing grooves 3, 4. By setting the angle at 70 ° or less, the ceramic substrate 1 can be broken along the division grooves 3 and 4 when the ceramic substrate 1 is divided. Therefore, it is preferable that the angles θ ₁ and θ ₂ of the dividing grooves 3 and 4 be set in the range of 40 ° to 70 °.

In order to manufacture such a ceramic substrate 1, for example, when the ceramic substrate 1 is made of alumina ceramics, first, an appropriate organic solvent and a solvent are added to a ceramic raw material powder such as alumina, silica, magnesia and the like. A ceramic green sheet is formed by adopting a conventionally known doctor blade method, a calender roll method, or the like, and then the ceramic green sheet is punched into a predetermined shape. A plurality of through holes 2, a plurality of first divided grooves 3 and a plurality of first divided grooves 3 are pressed against a ceramic green sheet by pressing a mold having a plurality of punches and a plurality of blades integrally implanted with a predetermined pressing force. The second dividing groove 4 is formed at the same time. At this time, the plurality of blades implanted in the mold
The first division groove 3 is formed such that the depth D ₁ of the first division groove 3 is smaller by a predetermined depth than the depth D ₂ of the second division groove 4.
Is arranged lower than the position of the blade for forming the second divided groove 4 by, for example, 0.02 to 0.06 mm. Finally, the ceramic green sheet is fired under predetermined conditions to complete the ceramic substrate 1 as a product. The ceramic substrate 1
In addition to the above-mentioned manufacturing method, it can also be manufactured by a powder press molding method or the like.In this case, an appropriate organic solvent and a solvent are added to and mixed with the ceramic raw material powder, and then dried and granulated. Is filled in a predetermined mold as a powder, and further pressurized and heated. Further, the through hole 2, the first divided groove 3, and the second divided groove 4 are formed at the same time by processing the inner surface of the mold into a predetermined shape according to these.

When the above-mentioned ceramic substrate 1 is used for "multiple-piece" production of electronic components, first, a conductive paste or the like is applied to one main surface or both surfaces of the ceramic substrate 1 in a predetermined pattern, and this is heated at a high temperature. A conductive pattern is formed by baking, and thereafter, an external force is applied to the ceramic substrate 1 using a predetermined jig to vertically move the ceramic substrate 1 along the first divided groove 3 and the second divided groove 4, The division is performed sequentially in the horizontal direction, whereby a plurality of single chips as shown in FIG. 3 are manufactured at the same time.

At this time, the dummy portion 1 of the ceramic substrate 1
a in the middle of the dummy portion 1a, specifically, in the direction in which the first divided groove 3 is formed,
By stopping at / 4, the mechanical strength of that portion is improved, so that cracking of the ceramic substrate 1 due to vibration or impact during transportation or the like is more reliably prevented, and the ceramic substrate 1 Reliability is further improved. Therefore, the first portion provided on the dummy portion 1a of the ceramic substrate 1
It is preferable that the dividing groove 3 be stopped at １ ／ to ／ of the middle of the dummy portion 1a.

The present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the gist of the present invention.

For example, in the embodiment described above, the depth D ₁ of the first divided groove 3 is made shallower than the depth D ₂ of the second divided groove 4 as a whole, but instead, as shown in FIG. The depth D ₁ of the first division groove 3 is formed to be shallower than the depth D ₂ of the second division groove 4 only in a region adjacent to the through hole 2;
Other parts may be formed at the same depth as the second division groove 4. In this case, the blade for forming the first division groove 3 is formed in a shape corresponding to the shape of the first division groove 3.

Further, in the above-described embodiment, one through hole 2 is divided into two by the first dividing groove 3. However, as shown in FIG. The present invention is also applicable to an embodiment in which the first divided groove 3 divides the light into four.

Further, as shown in FIG. 6A, an R surface having a radius of curvature of 0.01 to 0.5 mm is provided at the ridge line of the dividing groove 3 'provided on one main surface of the ceramic substrate 1, or as shown in FIG. b)
As shown in the above, if the C-plane is provided at the ridge of the dividing groove 3 ", there is also an advantage that cracks can be effectively prevented from being generated around the dividing groove 3" when the green sheet is formed.

(Experimental Example) As in the case of the ceramic substrate 1 shown in FIG.
Using a Ba / Nd / Ti based dielectric substrate of 60 mm, 35 mm × 35 mm as a sample, the depth D ₁ of the first division groove leading to the through hole is set to the depth D ₂ of the second division groove not leading to the through hole. In each case, the crack occurrence rate during the process and the splitting property when actually splitting were examined. Table 1 shows the results. The depth of the depth D ₂ of the second dividing grooves are all fixed to 0.20 mm, the number of samples is set to one by 100, and divided into these three stages of the overall evaluation to ○ △ ×.

[0032]

[Table 1]

As is clear from the above results, the depth D ₁ of the first divisional groove is preferably set to 90% or less of the depth D ₂ of the second divisional groove from the viewpoint of the crack occurrence rate. from the viewpoint of dividing properties, preferably the second divided more than 70% of the depth D ₂ of the groove.

Therefore, when the depth D ₁ of the first divided groove is comprehensively taken into consideration from the viewpoint of the reduction of the rate of occurrence of cracks in the process and the division property, the depth D ₁ is 70% or less of the depth D ₂ of the second divided groove. It can be seen that setting the range to 90% is optimal.

[0035]

According to the ceramic substrate of the present invention, the depth of the first divided groove passing over the through hole is made smaller than the depth of the second divided groove not passing over the through hole. Appropriate mechanical strength can be imparted to the portion of the ceramic substrate where the first division groove is provided. Therefore, cracking of the ceramic substrate due to vibration or impact during transportation or the like is effectively prevented, and the reliability of the ceramic substrate is improved. Can be improved. Further, according to the ceramic substrate of the present invention, since the first division groove is formed so as to communicate with the through hole, chipping hardly occurs at the edge of each single chip at the time of division of the ceramic substrate. Therefore, there is an advantage that the yield of electronic components obtained by the method is also improved.

Further, according to the ceramic substrate of the present invention, the depth of the first division groove is set to 70% to 90% of the depth of the second division groove.
%, When the ceramic substrate is made of a relatively fragile dielectric material, the splitting ability when dividing the ceramic substrate into a plurality of single chips is extremely good, and when the ceramic substrate is transported, etc. Cracking of the ceramic substrate can be more reliably prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a ceramic substrate of the present invention.

2A is a partial sectional view of a first dividing groove, and FIG. 2B is a partial sectional view of a second dividing groove.

FIG. 3 is a perspective view of a single chip obtained by dividing the ceramic substrate of FIG. 1;

FIG. 4 is a sectional view showing another embodiment of the ceramic substrate of the present invention.

FIG. 5 is a perspective view showing another embodiment of the ceramic substrate of the present invention.

FIGS. 6A and 6B are partial cross-sectional views showing a modification of the ceramic substrate of the present invention.

FIG. 7 is a perspective view of a single chip obtained by dividing a conventional ceramic substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ceramic substrate 2 ... Through hole 3 ... 1st division groove 4 ... 2nd division groove

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoshi Kosugi 10-1 Kawai, Gamo-cho, Gamo-gun, Shiga Prefecture

Claims (2)

[Claims] 1. A ceramic substrate having a through hole and having, on one main surface, a plurality of first division grooves communicating with the through hole and a plurality of second division grooves not communicating with the through hole. A ceramic substrate, wherein the first divisional groove is formed to have a depth at least in a region close to the through hole shallower than that of the second divisional groove. 2. The ceramic substrate according to claim 1, wherein the depth of the first division groove is 70% to 90% of the depth of the second division groove.