JP5511603B2 - Multiple wiring board - Google Patents

Description

  In the present invention, a plurality of wiring board regions having mounting parts for mounting electronic components such as semiconductor elements and surface acoustic wave elements are arranged vertically and horizontally, and in the respective wiring board areas, the periphery of the mounting part is viewed in a plan view. The present invention relates to a multi-cavity wiring board having a U-shaped wall portion.

  Conventionally, wiring boards used for mounting electronic components such as semiconductor elements and surface acoustic wave elements are made of a ceramic sintered body such as an aluminum oxide sintered body or a glass ceramic sintered body. A square plate-like substrate part having a mounting part for mounting and a square frame-like wall part made of a ceramic sintered body and laminated on the upper surface of the substrate part so as to surround the mounting part are provided.

  Such a wiring board is generally manufactured in the form of a so-called multi-cavity wiring board in which a plurality of wiring boards are obtained simultaneously from a single large-area mother board. In the multi-cavity wiring board, the wiring board regions to be the wiring boards as described above are arranged vertically and horizontally on the mother board, and the board portions and the wall portions of the adjacent wiring board regions are connected to each other.

  In the conventional wiring board and the multi-cavity wiring board, a recess (so-called cavity) for hermetically sealing electronic components is formed by the mounting portion and the wall portion. For example, a lid is bonded to the upper surface of the wall portion. By closing the recess, the electronic component mounted on the mounting portion is hermetically sealed.

  In the multi-piece wiring board, the dividing groove is formed along the boundary of the wiring board region, and the mother board is broken by applying a bending stress to the mother board across the dividing groove. Is divided into wiring boards. The dividing grooves are formed by making a cut at a predetermined depth on the upper and lower surfaces of the unfired mother board using a cutter blade or the like at the boundary between adjacent wiring board regions.

JP 2009-283645 A

  In recent years, a wiring board has been used in which a square frame-shaped wall portion laminated on a substrate portion is not formed on one side so that the mounting portion is opened to the outside (the wall portion is U-shaped). It has become like this. When manufacturing a large number of such wiring boards in the form of a wiring board, a plurality of wiring board regions to be individual wiring boards are arranged so that the sides where the wall portions are not formed are adjacent to each other, The division grooves are respectively formed on the upper and lower surfaces of the mother substrate, that is, the lower surface of the substrate portion and the upper surface of the wall portion. In this case, normally, the dividing groove is not formed on the exposed upper surface of the substrate portion on the side where the wall portion is not formed. This is because if the dividing groove on the upper surface side of the mother substrate is deepened until it reaches the upper surface of the substrate portion, the dividing groove on the upper surface side of the mother substrate becomes too deep compared to the dividing groove on the lower surface side, and the manufacturing process This is to suppress deformation of the unfired mother substrate (particularly the wall).

Therefore, if the mother board is broken by applying bending stress to the mother board so that the dividing groove on the upper surface of the wall portion is opened, the crack does not always advance along the boundary, and the crack is not removed from the boundary. In some cases, the substrate portion proceeds from the exposed upper surface to the lower surface. Accordingly, there is a problem in that it is difficult to divide along the boundary in the portion where the wall portion is not formed, and burrs and chips are likely to occur on the end surface side where the wall portion of the individual wiring board is not formed.

  The present invention has been completed in view of the above-described conventional problems, and the object thereof is that a wall portion is not formed on one side of the wiring board region, and the wall portion has a U-shape. Provided is a multi-piece wiring board in which a plurality of wiring board areas are arranged vertically and horizontally, and can suppress the occurrence of burrs and chips along the boundary of the wiring board area when divided. There is to do.

  The multi-cavity wiring board of the present invention is made of a ceramic sintered body, and is a flat lower mother board in which a plurality of rectangular wiring board regions having an electronic component mounting portion at the center of the upper surface are arranged vertically and horizontally. And a mother board made of a ceramic sintered body and laminated on the upper surface of the lower mother board and a frame-like upper mother board for forming a wall portion around the mounting portion in each wiring board region. A multi-cavity wiring board in which a dividing groove is formed on an upper surface of the board along a boundary of the wiring board area, and the upper mother board is not formed on one side of the wiring board area and the wall is formed. The portion is U-shaped, and a plurality of the wiring board regions are arranged so that one side where the upper mother board is not formed is adjacent to the lower mother board, At the boundary of the wiring board area In addition, a slit penetrating the lower mother substrate in the thickness direction is formed in a portion exposed along one side where the upper mother substrate is not formed, and the upper mother substrate adjacent to the slit is formed. A groove is formed on the inner side surface from the upper end to the lower end of the inner side surface.

  The multi-piece wiring board of the present invention is characterized in that, in the above configuration, the groove portion is formed so that a width gradually decreases from an upper end to a lower end of the inner side surface of the upper mother board. .

  The multi-piece wiring board of the present invention is characterized in that, in the above configuration, the slits are extended to the lower mother board located at the lower side of the upper mother board at both ends thereof.

  According to the multi-cavity wiring board of the present invention, each wiring board region is composed of a flat lower mother board arranged vertically and horizontally, and a ceramic sintered body, which are laminated on the upper surface of the lower mother board. For a multi-chip wiring board in which a dividing groove is formed in a mother board composed of a frame-like upper mother board for forming a wall portion around the mounting portion in the board area, the lower mother board is connected to the wiring board area. Since a slit that penetrates the lower mother substrate in the thickness direction is formed in a portion exposed along one side where the upper mother substrate is not formed at the boundary, a dividing groove of the lower mother substrate as a substrate portion Since the boundary of the lower mother board is separated in advance by slits in the regions where it is difficult to form, the mother board can be easily divided along the boundary of the wiring board region.

  In addition, since a groove is formed from the upper end to the lower end of the upper mother board on the inner surface of the upper mother board as a frame part adjacent to the slit, the upper surface of the upper mother board is divided when dividing the mother board. A crack that proceeds from the bottom of the groove can be easily guided along the groove to the slit portion of the lower mother substrate that is in contact with the lower end of the upper mother substrate. Therefore, it is easy to match the break (divided) position of the mother board from the groove with the dividing position by the slit, and it is effective for defects such as burrs and chips when dividing the mother board into individual wiring boards. Can be suppressed.

Therefore, in a multi-cavity wiring substrate in which a wall portion is not formed on one side of the wiring substrate region and a plurality of wiring substrate regions in which the wall portion is U-shaped are arranged vertically and horizontally on the mother substrate. It is possible to provide a multi-cavity wiring board that can suppress the occurrence of burrs, chips, etc. on the end face of the subsequent wiring board.

  Further, according to the multi-cavity wiring board of the present invention, when the groove portion is formed so that the width gradually decreases from the upper end to the lower end of the inner surface of the upper mother substrate, the groove portion is generated from the bottom portion of the dividing groove. The portion of the lower mother board that is in contact with the lower end of the upper mother board along the groove formed on the inner surface of the upper mother board from the upper end to the lower end of the upper mother board (the end of the slit) It is possible to make it proceed reliably, and it is possible to more effectively suppress the occurrence of burrs and chips on the individual wiring board.

  Further, according to the multi-cavity wiring board of the present invention, when the slit is extended to the lower mother board located below the upper mother board at both ends, the lower mother board is divided in advance by the slit. Since the portion of the lower mother board that is located below the groove is also separated by a slit in advance, the mother board can be more easily and reliably divided along the boundary. Can do.

(A) is a top view which shows a part in an example of embodiment of the multi-piece wiring board of this invention, (b) is sectional drawing in the XX 'line | wire of (a), (c) FIG. 4 is a cross-sectional view taken along line YY ′ in FIG. It is a principal part perspective view which expands and shows the principal part of the multi-cavity wiring board shown in FIG. It is a top view which shows typically the whole multi-piece wiring board shown in FIG. (A) And (b) is a schematic diagram (principal part perspective view) for demonstrating the effect of the multi-piece wiring board of this invention, respectively. It is a principal part perspective view which shows the principal part in the other example of embodiment of the multi-cavity wiring board of this invention. It is a principal part perspective view which shows the principal part in the other example of embodiment of the multi-cavity wiring board of this invention.

  A multi-piece wiring board and a wiring board according to the present invention will be described with reference to the accompanying drawings. FIG. 1A is a top view illustrating a part of an example of an embodiment of a multi-cavity wiring board according to the present invention, and FIG. 1B is a cross-sectional view taken along line XX ′ in FIG. FIG. 1C is a cross-sectional view taken along line YY ′ of FIG. 2 is a perspective view showing a main part of the multi-cavity wiring board shown in FIG. 1, and FIG. 3 is a plan view schematically showing the whole multi-cavity wiring board shown in FIG.

An upper mother board 109 is laminated on a lower mother board 108 in which a plurality of wiring board areas 102 having mounting portions 103 are arranged vertically and horizontally to form a mother board 101. The mother board 101 has a boundary 105 between the wiring board areas 102. A multi-cavity wiring board is basically configured by forming a dividing groove 106 along the line. The mother board 101 of such a multi-piece wiring board is divided along the boundary 105 of the wiring board region 102 to produce a piece of wiring board (not shown). The insulating substrate of the individual wiring board to be manufactured forms a wall portion around the mounting portion 103 on the three sides of the lower substrate on the upper surface of a rectangular flat plate-like lower substrate (not shown) having the mounting portion 103. A U-shaped upper substrate (not shown) is basically stacked and configured.

The mother board 101 is made of a ceramic sintered body, and has a flat lower mother board 108 in which a plurality of square-shaped wiring board regions 102 having electronic component mounting parts 103 are arranged vertically and horizontally in the center of the upper surface, A frame-like upper mother board made of a ceramic sintered body and laminated on the upper surface of the lower mother board 108 to form a wall (no symbol) around the mounting part 103 in each wiring board region 102
109.

Note that the upper mother substrate 109 has only a U-shaped wall with respect to one wiring substrate region 102, and is not a frame shape surrounding the mounting portion 103, but is adjacent to each other. The mounting portions 103 of the two wiring board regions 102 are collectively enclosed in a frame shape, and are formed in a frame shape as a whole.

  The lower mother substrate 108 and the upper mother substrate 109 are an aluminum oxide sintered body, a glass ceramic sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a silicon nitride sintered body, and a mullite sintered body. Etc. are formed of a ceramic sintered body.

  In the example of this embodiment, as shown in FIG. 3, a dummy area (no symbol) is provided on the outer periphery of the mother board 101 which is a multi-piece wiring board so as to surround a plurality of wiring board areas 102 arranged. Is provided. The dummy area is provided to facilitate handling of the multi-piece wiring board.

The mother board 101 is produced, for example, by integrally firing a lower mother board 108 and an upper mother board 109. That is, a suitable organic solvent and binder are added to raw powders such as aluminum oxide and silicon oxide and formed into a sheet shape to produce a plurality of ceramic green sheets. After forming into a frame, a frame-shaped ceramic green sheet is laminated on a flat ceramic green sheet that has not been punched, and the laminate is integrally fired to form a mother substrate 101 made of an aluminum oxide sintered body or the like. Can be produced. In this case, a flat ceramic green sheet becomes the lower mother substrate 108,
A frame-shaped ceramic green sheet becomes the upper mother substrate 109.

The plurality of wiring board regions 102 arranged on the lower mother board 108 have electronic component mounting portions 103 in the center or the like, and each is a region that becomes a lower board of the individual wiring board. A frame-shaped upper mother substrate 109 is laminated on the lower mother substrate 108 to form a mother substrate 101. The upper mother substrate 109 is for forming a wall portion around the mounting portion 103, and serves as the upper substrate 109 of the individual wiring substrate. The wall portion is for protecting an electronic component (not shown) mounted on the mounting portion 103.

Examples of electronic components mounted on the mounting unit 103 include various types of piezoelectric elements such as crystal oscillators, surface acoustic wave elements, semiconductor elements such as semiconductor integrated circuit elements (ICs), capacitive elements, inductor elements, resistors, and the like. Mention electronic components.

  In the example shown in FIGS. 1 to 3, a part of the wiring conductor 104 is formed on the mounting portion 103. The wiring conductor 104 is formed, for example, from the mounting portion 103 through the inside of the mother board 101 to a portion that becomes the outer surface of the individual wiring board, such as the lower surface of the mother board 101. Of the wiring conductors 104, those formed inside the mother board 101 are in the form of through conductors (so-called via conductors) or internal wiring layers. If an electronic component mounted on the mounting portion 103 is electrically connected to the wiring conductor 104, the electronic component can be electrically connected to an external electric circuit via the wiring conductor 104.

The wiring conductor 104 is made of, for example, copper, silver, palladium, gold, platinum, tungsten, molybdenum,
Made of a metal material such as manganese. If the wiring conductor 104 is made of copper, for example, a metal paste (not shown) prepared by adding an organic solvent and a binder to copper powder is applied to a ceramic green sheet serving as the base substrate 101 in a predetermined pattern. It can be formed by simultaneous firing.

In this multi-piece wiring board, the upper mother board 109 is not formed on one side of the rectangular wiring board area 102 and the lower mother board 108 is exposed to the boundary 105 of the wiring board area 102. In other words, in this multi-cavity wiring board, the mounting portion 103 of the wiring board region 102 is not surrounded by the wall portion around the entire circumference, but the wall portion is U-shaped, and the wiring board region 102 has a rectangular shape. 1
The mounting portion 103 is open to the outside at one side.

The range where the upper mother substrate 109 is not formed is as shown in FIG.
It does not extend over the entire length of one side, and does not extend to a portion that intersects (perpendicular to) two sides that touch this one side. In other words, the upper mother board 109 corresponding to the two sides reaches the boundary 105 of the wiring board region 102, and the mounting portion 103 is opened to the outside between the two sides. The plurality of wiring board regions 102 are arranged so that one side where the upper mother board 109 is not formed is adjacent to each other, and the upper mother boards 109 corresponding to the two sides are connected to each other.

A wiring board produced by dividing a multi-piece wiring board having such a configuration into individual pieces is used for applications such as a TV tuner module for mobile phones. In the case of this application, a tuner IC (not shown), which is an electronic component, is mounted on the mounting portion 103, and this is covered with a sealing material (not shown) such as resin and sealed. Is produced. In this case, a tuner IC is mounted on the mounting portion 103 of each wiring board region 102 in the state of a multi-piece wiring board, and an OFDM chip (orthogonal freqeuncy) is formed on the lower surface of the mother board 101 (lower mother board 108).
division multiplex: an orthogonal frequency division multiplex system (not shown) may be mounted, and then divided into individual wiring boards (individual electronic devices in which electronic components are mounted on the wiring boards). The electrodes of the tuner IC are electrically connected to the wiring conductor 104 via solder (not shown), and the OFDM electrodes are formed on the lower surface side of the mother board 101 via bonding wires or the like (not shown). It is electrically connected to a wiring conductor (not shown).

In order to divide the mother board 101, dividing grooves 106 are formed on the upper surface of the upper mother board 109 and the lower surface of the lower mother board 108 along the boundary 105 of the wiring board region 102. The mother board 101 is divided into individual wiring boards by applying stress to the mother board 101 at the portion where the dividing groove 106 is formed (the boundary 105 of the wiring board region 102) and breaking the mother board 101 in the thickness direction. Is done.

  These dividing grooves 106 are formed on the laminated body of ceramic green sheets to be the mother board 101, on the lower surface of the ceramic green sheet to be the lower mother board 108, and on the upper surface of the ceramic green sheet to be the upper mother board 109. It is formed by making a cut along the boundary 105 with a cutter blade or the like.

In the multi-cavity wiring board of the present invention, a slit that penetrates the lower mother board 108 in the thickness direction at a portion exposed along one side where the upper mother board 109 is not formed at the boundary 105 of the wiring board region 102. 110 is formed, and a groove 111 is formed on the inner surface of the upper mother substrate 109 adjacent to the slit 110 from the upper end to the lower end of the upper mother substrate 109.

The slit 110 has a band shape in plan view and penetrates the lower mother substrate 108 in the thickness direction. The slit 110 is for facilitating the division of the mother board 101. Further, when dividing the mother substrate 101, the groove portion 111 guides a crack generated from the dividing groove 106 on the upper surface of the upper mother substrate 109 to the position where the slit 110 is formed, that is, the boundary 105 of the wiring substrate region 102. belongs to.

That is, according to the multi-cavity wiring board of the present invention, since the above-described configuration is provided, the lower mother board 108 is separated in advance by the slit 110 in a portion where it is difficult to form the dividing groove 106 of the lower mother board 108 as the board part. Therefore, it is easy to divide the mother board 101 along the boundary 105 of the wiring board region 102.

Further, on the inner side surface of the upper mother substrate 109 as a frame portion adjacent to the slit 110, the upper mother substrate
Since the groove portion 111 is formed from the upper end to the lower end of 109, cracks generated from the dividing groove 106 on the upper surface of the upper mother substrate 109 when the mother substrate 101 is divided are formed along the groove portion 111 in the lower mother substrate 108. It can be easily guided to the slit 110 portion. Therefore, the mother substrate 101 from the groove 111
It is easy to match the break (split) position of the slit and the split position by the slit 110, and it is possible to effectively suppress defects such as burrs and chips when the mother board 101 is divided into individual wiring boards. it can.

Therefore, in a multi-piece wiring board in which a plurality of wiring board regions 102 in which a wall portion is not formed on one side of the wiring board region 102 and the wall portions are U-shaped are arranged, the end face of the divided wiring board Thus, it is possible to provide a multi-cavity wiring board capable of suppressing the occurrence of burrs and chips on the side.

In this case, if the slit 110 is simply formed, for example, as shown in FIG. 4A, a crack generated in the portion where the dividing groove 106 is formed on the upper surface of the upper mother substrate 109 is slit into the mother substrate 101. May deviate from 110. Further, a part of the mother board 101 adjacent to the slit 110, that is, a part of the lower mother board 108 in contact with the slit 110, is broken by a mechanical shock when a crack progresses from the upper mother board 109 to the lower mother board 108. May cause mechanical destruction. On the other hand, if the groove 111 is formed as described above, for example, FIG.
As shown, the crack can be advanced along the groove 111 to be led to the position where the slit 110 is formed. In addition, since the groove 111 is formed, the upper mother substrate 109 is easily broken, and the mechanical shock when the crack progresses from the upper mother substrate 109 to the lower mother substrate 108 can be suppressed low. For this reason, it is possible to effectively suppress defects such as burrs and burrs when the mother board 101 is divided into individual wiring boards. 4 (a) and 4 (b) are schematic views (perspective views of essential parts) for illustrating the effect of the multi-piece wiring board of the present invention. 4, parts similar to those in FIGS. 1 to 3 are denoted by the same reference numerals.

The slit 110 is formed on a portion of the boundary 105 of the wiring board region 102 that is exposed when a frame-shaped ceramic green sheet is laminated in a later step on the ceramic green sheet that becomes the lower mother substrate 108, a mold, or the like. A portion that penetrates in the thickness direction by a method such as mechanical punching using a laser or laser processing is formed by providing a predetermined shape and size of the slit 110 in plan view (considering firing shrinkage). be able to. In this case, the length of the slit 110 may be slightly longer than a predetermined length in consideration of stacking deviation and the like.

  The groove 111 contacts (is orthogonal to) one side that is not formed at the boundary 105 of the wiring board region 102 when the ceramic green sheet to be the upper mother board 109 is punched into a frame shape as described above. The inner side surfaces of the two sides may be processed to form grooves using a mold or the like from the upper end to the lower end at a portion corresponding to the boundary 105 of the wiring board region 102. The formed groove becomes the groove 111.

The width of the slit 110 formed in the lower mother substrate 108 is, for example, about 0.2 to 0.5 mm when both the upper mother substrate 109 and the lower mother substrate 108 are made of an aluminum oxide sintered body. For example, if the wiring board region 102 has a square shape with a side length of about 3 to 10 mm and the area of the mounting portion 103 is about 5 to 80 mm ² , the width of the wall portion is about 0.25. The width of the groove 111 formed on the upper mother substrate 109 may be set to be slightly narrower than the width of the slit 110, that is, about 0.15 to 0.4 mm. As a result, cracks that have progressed from the dividing groove 106 on the upper surface follow the groove 111 formed on the inner surface of the upper mother substrate 109 from the upper side of the wall portion to the end of the dividing groove 106 on the lower surface of the substrate portion (lower mother substrate 108). In addition to being able to advance accurately over the portion, the crack progresses within the range of the width of the slit 110.

Here, the shape of the groove 111 in plan view is a semicircular shape in FIG. This is to prevent the cracks from coming off the boundary 105 when the cracks proceeding from the upper split grooves 106 travel along the grooves 111 formed on the inner side surface of the upper mother substrate 109. Since the shape of the groove 111 is semicircular, cracks are induced at the bottom of the semicircular groove 111, that is, the narrowest part of the wall, thus preventing cracks from coming off the boundary 105. There is an effect to. As long as the shape of the groove 111 in plan view is such that the portion having the narrowest width of the wall is formed, the same effect is obtained. The shape of the groove 111 in plan view is, for example, V-shaped or U
It may be a letter shape.

According to such a multi-cavity wiring board of the present invention, since the upper mother board 109 is not formed and the upper surface of the lower mother board 108 is exposed up to the slit 110 in the wiring board region 102, the lower mother board 108 is exposed. This is advantageous in ensuring a large area of the mounting portion 103 on which the electronic component is mounted. Further, in this case, since the wall portion is formed in a U-shape, the electronic component can be more reliably protected than the multi-layer wiring substrate in which the mother substrate 101 is a flat plate. Sealing is easy. For example, after mounting an electronic component on a mounting portion (not shown) of an individual wiring board, if one side of the opened mounting portion is closed with a member (not shown) such as a metal fitting or glass, a frame shape As in the case of the wall portion, hermetic sealing with a lid or the like can be performed. Such a member can be made to transmit and receive signals such as light and electricity between an electronic component and an external electric circuit through an optical fiber, electric wiring, or the like.

Further, according to the multi-piece wiring board of the present invention, in the above configuration, for example, as shown in FIG. 5, the groove portion 111 gradually decreases in width from the upper end to the lower end of the inner side surface of the upper mother substrate 109. If formed, a crack that proceeds from the bottom of the dividing groove 106 is slit along the groove 111 formed on the inner surface of the upper mother substrate 109 so as to contact the lower end of the upper mother substrate 109. It is possible to proceed more accurately by the portion where 110 is formed, and it is possible to more effectively suppress the occurrence of burrs and chips on the individual wiring board.

That is, in this case, since the width of the groove 111 is relatively wide on the upper end side of the upper mother substrate 109, it is easy to cause cracks in the upper mother substrate 109 at the position of the groove 111. The direction in which the crack progresses is gradually narrowed toward the upper mother substrate 109 more securely.
Among them, a crack can be caused to progress in a portion where the slit 110 is formed.

If the width of the slit 110 formed in the lower mother substrate 108 is about 0.2 to 0.5 mm, for example, the lower width of the groove 111 formed in the upper mother substrate 109 is smaller than the width of the slit 110. What is necessary is just to form in the width | variety which becomes a little narrow, ie, about 0.15-0.4 mm. Further, the upper width of the groove 111 formed in the upper mother substrate 109 may be formed so as to be slightly wider than the width of the slit 110, that is, about 0.3 to 0.7 mm. As a result, the crack progressing from the split groove 106 on the upper surface is guided to progress within the width of the groove 111, and the crack progresses accurately from the upper mother substrate 109 to the split groove 106 on the lower surface of the lower mother substrate 108. Can be made.

Further, according to the multi-piece wiring board of the present invention, in the above configuration, as shown in FIG. 6, for example, the slit 110 has the lower mother board 108 positioned at the lower side of the upper mother board 109 at both ends thereof.
The lower mother substrate 108 is preliminarily divided by the slit 110, and the portion of the lower mother substrate 108 located below the groove 111 is also previously formed by the slit 110. Due to the separation, the mother substrate 101 can be more easily and reliably divided along the boundary 105. In this case, it can be considered that the groove 111 extends to the lower surface of the mother substrate 101.

The dividing groove 106 is for breaking the mother substrate 101 along the dividing groove 106 and dividing it into individual wiring boards. As described above, the division grooves 106 include those formed on the upper surface of the upper mother substrate 109 and those formed on the upper surface of the lower mother substrate 108. These dividing grooves 106
Are on the same boundary 105 of the wiring board region 102 and continue in a straight line in plan view. Further, among the divided grooves 106 formed in the upper mother board 109, the divided grooves 106 formed across the walls of the adjacent wiring board regions have a structure in which the rigidity of the mother board 101 is relatively maintained. Therefore, the depth is formed deeply (about 50 to 70% of the thickness of the upper mother substrate 109),
The split groove 106 formed at the boundary 105 where the slit 110 is formed has a structure in which the rigidity of the mother substrate 101 is less likely to be maintained by the amount of the slit 110 formed, and thus is formed shallower than the other parts (upper part) It is preferable that the thickness of the base substrate 109 is about 30 to 50%. By adopting such a structure, it is possible to realize a multi-piece wiring board that satisfies both the handleability in the manufacturing process of the mother board 101 and the division ability at the time of division.

Here, the effect of the multi-piece wiring board 101 of the present invention is formed by laminating an upper mother board 109 having a thickness of about 0.4 mm on a lower mother board 108 made of an aluminum oxide sintered body and having a thickness of about 0.3 mm. A specific example is given by taking a multi-chip wiring board as an example in which a plurality of wiring board regions 102 to be individual wiring boards are arranged on the mother board 101 so that the sides where the wall portions are not formed are adjacent to each other. Explained. In this multi-piece wiring board, the wiring board region 102 has a rectangular shape with a long side (side on which the slit 110 is formed) having a length of 10 mm and a short side having a length of 8 mm.

  In the above example, on one side of the wiring board region 102, the dividing groove 106 is formed at a depth of about 0.2 mm on the lower surface of the lower mother board 108 exposed without forming the upper mother board 109, and the upper mother board is formed. A dividing groove 106 was formed at a depth of about 0.15 mm on the upper surface of 109, and this was divided along the dividing groove 106, and the presence or absence of burrs and cracks was visually confirmed (magnification about 20 times).

The mother board 101 has a rectangular shape with a long side length of 110 mm and a short side length of 94 mm (the width of the dummy area is 15 mm in both vertical and horizontal directions). Arranged. Also, as a comparative example, a multi-cavity wiring board of the prior art, that is, a multi-cavity wiring board having a shape in which the slit 110 and the groove 111 are not formed on the side where the mounting portion 103 of the wiring board region 102 is opened, is prepared. It was divided along the dividing groove to confirm the presence or absence of burrs and cracks. In both the multi-cavity wiring board of the specific example of the present invention and the multi-cavity wiring board of the comparative example, the number of mother boards (101) tested was 10 (about 640 individual wiring boards).

  As a result, burrs and cracks were not observed in the multi-cavity wiring board of the present invention, whereas burrs were observed in 13 wiring boards of the multi-cavity wiring board of the comparative example. Thereby, the effect which suppresses generation | occurrence | production of the burr | flash and crack in the multi-cavity wiring board of this invention was able to be confirmed.

Note that the multi-piece wiring board of the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the gist of the present invention. For example, the insulating layer constituting the mother substrate 101 may have a three-layer structure instead of two layers, and the wall portion may be composed of two insulating layers. Further, when the wall portion is composed of two insulating layers, the width of the groove 111 is formed wider in the upper insulating layer and the width of the groove 111 is narrowed in the lower insulating layer, and the center of each groove 111 is formed. It is also possible to suppress burrs and chipping at the time of division by stacking so as to match.

101 ... Mother board
102 ・ ・ ・ Wiring board area
103 ・ ・ ・ Mounting part
104 ... Wiring conductor
105 ... Boundary
106 ・ ・ ・ Dividing groove
108 ・ ・ ・ Lower mother board
109 ... Upper mother board
110 ... Slit
111 ・ ・ ・ Groove

Claims (3)

A ceramic sintered body, and a plurality of square-shaped wiring board regions having an electronic component mounting portion in the center of the upper surface, and a plate-like lower mother board arranged vertically and horizontally, and a ceramic sintered body, On the upper surface of the mother board, which is stacked on the upper surface of the lower mother board and is formed of a frame-like upper mother board for forming a wall portion around the mounting portion in each of the wiring board areas, A multi-piece wiring board in which dividing grooves are formed along a boundary, wherein the upper mother board is not formed on one side of the wiring board region, and the wall portion has a U-shape. In addition, a plurality of the wiring board regions are arranged so that one side where the upper mother board is not formed is adjacent to each other, and the lower mother board is arranged at the boundary of the wiring board area with the upper mother board. The substrate is not formed A slit that penetrates the lower mother substrate in the thickness direction is formed in a portion exposed along one side, and an inner surface of the upper mother substrate adjacent to the slit is formed from an upper end of the inner surface. A multi-cavity wiring board characterized in that a groove is formed at the lower end. 2. The multi-piece wiring board according to claim 1, wherein the groove is formed so that a width gradually decreases from an upper end to a lower end of the inner side surface of the upper mother board. 2. The multi-piece wiring board according to claim 1, wherein the slit is extended to the lower mother board located below the upper mother board at both ends thereof.

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