JPH10223994A - Electronic circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic circuit board which can be smoothly divided into subordinate substrates along breaking grooves at a high yield. SOLUTION: An electronic circuit board 10 is composed of a platy ceramic board and subordinate substrates 11a and 11b are demarcated on the board 10. Between the subordinate substrates 11a and 11c, a breaking groove 13 is provided for separating the substrates 11a and 11c from each other, and many through holes 14 which intersect the groove 13 are arranged. In addition, surface electrodes 17 are formed around the through holes 14 in such a state that both end sections of the electrodes 17a and 17b are disposed separately at a specified interval from the groove 13, and through hole electrodes 18 which are electrically connected to the surface electrodes 17 having facing both end sections 17a and 17b are formed on the internal surfaces of the through holes 14, and continuously connected to each other at spots which are provided at a fixed interval from the bottom section 19 of the groove 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electronic circuit board, and more particularly, to an electronic circuit board having a break groove and a through hole.

[0002]

2. Description of the Related Art FIG. 6A is a partially enlarged view of a conventional electronic circuit board including a plurality of sub-boards, and FIG.
6A is a cross-sectional perspective view taken along line VI-VI in FIG. The electronic circuit board 50 is provided with a break groove 51 around each of the daughter boards 51a and 51b for separating from a removal edge or another daughter board. Also, a large number of through holes 52 are arranged so as to intersect with the break grooves 51. The plurality of lead patterns 53 extending to the side of each through hole 52 are continuous with the surface electrode 54 formed on the entire periphery of the opening of the through hole 52. This surface electrode 54 is
Extends to the back surface of the electronic circuit board 50 via the through-hole electrode 55 formed on the inner surface of the electronic circuit board 50.

In the electronic circuit board 50 having such a configuration,
When the sub-boards 51a and 51b and the removal edges (not shown) are divided by the break grooves 51, the sub-boards 51a and 51b on which predetermined circuits are formed are obtained. The obtained sub-boards 51a and 51b are used as surface mounting boards.

[0004]

However, in the above-mentioned conventional electronic circuit board, the surface electrode is formed all around the opening of the through-hole, and the through-hole electrode electrically connected to the surface electrode is formed. When the electronic circuit board is divided into sub-boards along the break groove, the surface electrode formed in the break groove and the through-hole electrode located immediately below the bottom of the break groove are obstacles when forming the electronic circuit board along the break groove. Therefore, there is a problem that the electronic circuit board is not divided smoothly along the break groove, and chipping or cracking occurs in each of the daughter boards.

Further, when the electronic circuit board is divided into the respective sub-boards, a defect that the surface electrode or the through-hole electrode is peeled off occurs, and there is also a problem that the yield of the sub-boards is deteriorated.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an electronic circuit board which is smoothly divided into sub-boards along break grooves and has a good yield of the sub-boards. Aim.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of forming a plurality of through-holes over a break groove formed for dividing a daughter board. An electronic circuit board comprising a surface electrode formed around the periphery of the substrate, and a through-hole electrode formed on the inner surface, wherein both end portions of the surface electrode are located at positions separated by a predetermined distance from an edge of the break groove. The through-hole electrodes are electrically connected at opposite ends thereof to surface electrodes facing each other, and are connected to each other at locations spaced apart from the bottom of the break groove by a predetermined distance.

According to the electronic circuit board of the present invention, the surface electrode is formed at the edge of the break groove and the through-hole electrode is formed so as not to contact the bottom of the break groove. The surface electrode and the through-hole electrode do not hinder.

[0009]

FIG. 1 is a plan view showing an embodiment of an electronic circuit board according to the present invention. The electronic circuit board 10 is a ceramic flat board, and includes four sub-boards 11a to 11c.
11d. The removal edge 12 or other child substrates 11a to 11d are provided around each of the child substrates 11a to 11d.
A break groove 13 is provided for separation from d. Also, a large number of through holes 14 intersecting with the break grooves 13 are arranged.

An electronic component such as an IC chip is mounted on the center of the upper surface of each of the daughter boards 11a to 11d, and a ground electrode 15 connected to the ground terminal is arranged. Around the ground electrode 15, a plurality of lead patterns 16 extending from the vicinity of the ground electrode 15 to the side of each through hole 14 are independently arranged. Each lead pattern 16 is connected to a surface electrode 17 formed near the periphery of the through hole 14.

FIG. 2A is an enlarged plan view of a portion A in FIG. 1, and FIG. 2B is a cross-sectional perspective view taken along the line II-II in FIG. 2A. Both ends 17a, 1 of the surface electrode 17
As shown in FIG. 2A, 7b is located at a position spaced apart from the break groove 13 by a predetermined distance. That is, both ends 17
a, 17b are opposed to the surface electrode 17
And are not formed continuously.

On the other hand, each surface electrode 1 formed on the inner surface of the through hole 14 and having opposite ends 17a and 17b facing each other.
As shown in FIG. 2B, the through-hole electrodes 18 electrically connected to each other are connected to each other at a position spaced from the bottom 19 of the break groove 13 by a constant distance, and the edges have a substantially U-shape. It is continuous as it does.

When the electronic circuit board 10 is divided, the sub-boards 11a (to 11d) as shown in FIG.
Is obtained. On the side surface of the daughter board 11a, a through-hole electrode 18 electrically connected to the surface electrode 17 on the front surface is formed.

The electronic circuit board 10 having the above configuration
An example of the manufacturing process of FIG. 1 is shown. First, a through hole 14 is formed at a desired position of a ceramic sheet obtained by kneading a ceramic material and extending the sheet by punching or the like. Next, these ceramic sheets are laminated so that the through holes 14 coincide with each other, and pressed to form a flat ceramic substrate having the through holes 14. At this time, a break groove 13 is formed along a boundary line between the daughter boards 11a to 11d, and the break groove 13 is formed at the same time when the ceramic substrate is pressed.

Next, the pressed ceramic substrate is semi-baked, and after the respective patterns of the ground electrode 15, the lead pattern 16, the surface electrode 17, and the through-hole electrode 18 are printed, the substrate is completely baked. And FIG.
For example, when the surface electrode 17 is screen-printed, a part of the through-hole 14 is masked with an organic resin or the like, and the electrode paste is sucked from the back surface of the through-hole electrode 18 having the shape shown in FIG. Then, it is formed by removing the mask.

The electronic circuit board 10 manufactured as described above
Can be divided for each of the sub-boards 11a to 11d.
A large number of different types or the same type of electronic circuits can be formed, and mass production of a child substrate having each electronic circuit can be achieved.

According to the electronic circuit board of the present embodiment as described above, the surface electrode is formed at the edge of the break groove and the through-hole electrode is formed so as not to contact the bottom of the break groove. When the electronic circuit board is divided into the respective sub-boards, the surface electrodes and the through-hole electrodes do not hinder. Therefore, since it can be divided smoothly along the break groove, chipping or cracking does not occur in each child substrate,
In a manufacturing process of obtaining a sub-board from an electronic circuit board, the yield is improved.

Further, when the electronic circuit board is divided into the sub-boards, the occurrence of defects such as peeling of the conductive pattern is reduced. Therefore, a highly reliable child substrate can be manufactured.

Furthermore, the portion where the through-hole electrode is not formed triggers the electronic circuit board to be easily divided, so that the manufacturing process of the daughter board can be simplified.

Further, since the through-hole electrodes whose both ends are electrically connected to the opposing surface electrodes are connected to each other, each surface electrode and each through-hole electrode can be made continuous in the electronic circuit board. Therefore, by connecting the plating electrode to the surface electrode present at the removed edge, it is possible to easily perform plating on each surface electrode and each through-hole electrode.

FIGS. 4 and 5 show the electronic circuit board 10 of FIG.
5A and 5B are a top view and a cross-sectional view taken along line VV in FIG. 4 when the child boards 11a (to 11d) obtained from FIG.

The electrode 21 disposed on the motherboard 20 and the through-hole electrode 18 disposed on the side surface of the daughter board 11a
Have the same pitch so as to face each other. And
The electrodes 21 on the motherboard 20 and the through-hole electrodes 18 on the side surfaces of the child substrate 12 are fixed by solder 22 by reflow soldering or the like. At this time, the solder 22 creeps up along the through-hole electrode 18 and has a large soldering area, so that a mechanically strong solder can be obtained. Note that a protective layer 23 made of a resin potting layer is provided on the sub-substrate 11a to protect elements mounted on the sub-substrate 11a.

In the above-described embodiment, the shape of the through-hole is substantially elliptical, but any shape such as a circle or a rectangle may be used as long as the surface electrode does not contact the break groove.

Although the case where the through-hole electrodes are connected to each other near the back surface of the electronic circuit board has been described, any portion of the through-hole may be connected as long as it does not contact the bottom of the break groove.

[0025]

According to the electronic circuit board of the present invention, since the surface electrode is formed at the edge of the break groove and the through-hole electrode is formed so as not to contact the bottom of the break groove, the electronic circuit board is formed along the break groove. When the substrate is divided into sub-substrates, the surface electrodes and the through-hole electrodes do not hinder. Therefore, since it can be divided smoothly along the break groove, chipping or cracking does not occur in each sub-board, and the yield is improved in the manufacturing process of obtaining the sub-board from the electronic circuit board.

In addition, when the electronic circuit board is divided into the sub-boards, the occurrence of defects such as peeling of the conductive pattern is reduced. Therefore, a highly reliable child substrate can be manufactured.

Furthermore, since the portion where the through-hole electrode is not formed triggers the electronic circuit board to be easily divided, the manufacturing process of the daughter board can be simplified.

Further, since the through-hole electrodes whose both ends are electrically connected to the opposing surface electrodes are connected to each other, each surface electrode and each through-hole electrode can be made continuous in the electronic circuit board. Therefore, by connecting the plating electrode to the surface electrode present at the removed edge, it is possible to easily perform plating on each surface electrode and each through-hole electrode.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of an electronic circuit board according to the present invention.

FIG. 2A is an enlarged plan view of a portion A in FIG. 1;
(B) is a sectional perspective view taken along line II-II of (a).

FIG. 3 is a partially enlarged perspective view of a child board obtained from the electronic circuit board of FIG. 1;

FIG. 4 is a top view when the child board of FIG. 3 is mounted on a motherboard.

FIG. 5 is a sectional view taken along line VV in FIG. 4;

6A is a partially enlarged plan view showing a conventional electronic circuit board, and FIG. 6B is a cross-sectional perspective view taken along line VI-VI of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electronic circuit board 11a-11d Substrate 13 Break groove 14 Through hole 17 Surface electrode 18 Through hole electrode 17a, 17b Both ends 19 Bottom

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Koki Nishimura 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Stock Company Murata Manufacturing Co., Ltd. (72) Inventor Kenji Kubota 2-26-10 Tenjin, Nagaokakyo-city, Kyoto Stock (72) Inventor Toshiro Adachi 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Inside Murata Manufacturing Co., Ltd.

Claims (1)

[Claims] A plurality of through holes are formed so as to straddle a break groove formed for dividing into a daughter board, a surface electrode formed around the through hole, and a through electrode formed on an inner surface. An electronic circuit board comprising: a hole electrode; wherein both end portions of the surface electrode are located at positions separated by a predetermined distance from an edge of the break groove; and the through hole electrode is a surface electrode whose both end portions face each other. An electronic circuit board, which is electrically connected to the circuit board and is connected to each other at a location separated by a predetermined distance from the bottom of the break groove.