JP2015090889A - Multi-piece wiring board, wiring board and electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-piece wiring board and the like which can easily manufacture a wiring board in which reflection of light from an insulating substrate surface on the outside of a mounting part of a light emitting element is reduced.SOLUTION: A multi-piece wiring board 10 comprises: a mother board 1 which is composed of a ceramic sintered compact and in which a plurality of wiring board regions 2 are arranged, and which has mounting parts 2a of light emitting elements formed on respective central parts of the plurality of wiring board regions 2 and has a top face including split grooves 3 formed along boundaries of the plurality of wiring board regions 2; and an absorption layer 7 which is composed of a darkly-colored coloring material and formed on the top face of the mother board 1 from outer circumferences of the wiring substrate regions to the middle of an internal surface of each split groove 3 in a height direction. Since the absorption layer 7 is not formed to a bottom of the split groove 3, mechanical destruction of the absorption layer 5 at the time of splitting the mother board 1 is inhibited and reflection of light from the outside of the mounting part 2a is reduced by the absorption layer 5.

Description

  According to the present invention, a plurality of wiring board regions serving as wiring boards for mounting light emitting elements are arranged vertically and horizontally on a mother board, and individual wirings are formed along divided grooves formed at the boundaries of the wiring board regions. The present invention relates to a multi-piece wiring board or the like divided into substrates.

  A wiring board used for mounting a light emitting element such as a light emitting diode includes a rectangular plate-shaped insulating substrate made of a ceramic sintered body such as a glass ceramic sintered body or an aluminum oxide sintered body, and an upper surface of the insulating substrate. And a light emitting element mounting portion provided. A light emitting element is mounted on the mounting portion. Part of the light (visible light) emitted by the light emitting element is reflected by the upper surface including the mounting portion of the insulating substrate and radiated to the outside. In order to increase the light reflectivity, generally, the upper surface of the insulating substrate is white with high light reflectivity. For this purpose, an insulating substrate is formed of a white material such as an aluminum oxide sintered body.

  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. The multi-cavity wiring board has, for example, a structure in which a plurality of wiring board regions serving as wiring boards are arranged vertically and horizontally on a flat mother board. Such a multi-piece wiring board is divided into individual wiring boards by providing a dividing groove in advance at the boundary of the wiring board region and breaking the mother board along the dividing groove.

JP 2013-197236 JP 2013-187222 JP 2010-118560 A

  In recent years, the wiring board as described above has been widely used as a substrate for manufacturing a light emitting device for a backlight such as a liquid crystal display device. In this case, the portion where the light emitting element is mounted on the upper surface of the insulating substrate is required to have high light reflectance, but the light reflectance is required to be as low as possible in the portion outside the mounting portion. It is getting to be.

  This suppresses the upper surface of the insulating substrate in the portion outside the mounting portion from being reflected on the liquid crystal display device (liquid crystal screen) when a light emitting device in which a light emitting element is mounted on a wiring board is used as a backlight. It is to do. When the reflectance of the upper surface of the insulating substrate in the part outside the mounting part is high, a part of the upper surface of the insulating substrate may be visible from the outside through the liquid crystal screen, which may hinder normal image display There is sex.

  For such problems, for example, by adding a pigment such as a metal oxide to the material forming the mother substrate and coloring the insulating substrate to a dark color such as black or brown, the insulation of the individual pieces A means for suppressing the reflection of light on the upper surface of the substrate can be considered. However, in this case, the reflectance of light in the mounting portion decreases, and the amount of light emitted to the outside as the light emitting device decreases.

A multi-cavity wiring board according to one aspect of the present invention is made of a ceramic sintered body, and a plurality of wiring board regions are arranged, and a light emitting element provided at the center of each of the plurality of wiring board regions And a mother board having an upper surface including a dividing groove provided along a boundary of each of the plurality of wiring board regions, and a dark colorant, and the wiring board among the upper faces of the mother board And a light absorbing layer provided from the outer periphery of the region to the middle of the inner surface of the dividing groove in the height direction.

  A wiring board according to one aspect of the present invention is characterized in that the plurality of wiring board regions included in the multi-piece wiring board having the above-described configuration are divided into pieces.

  An electronic component according to one aspect of the present invention includes the wiring board having the above configuration and a light emitting element mounted on the mounting portion.

  According to the multi-cavity wiring board of one aspect of the present invention, the light absorption layer is provided from the outer peripheral portion to the groove for each of the plurality of wiring board areas arranged on the mother board. When the light emitting element is mounted at the center of the light, the reflectance of light at the center is high, and the reflection of light at the outer periphery is effectively suppressed. In addition, since the light absorption layer is provided halfway along the inner surface of the dividing groove and does not reach the bottom of the dividing groove, the light absorbing layer is mechanically separated when the mother substrate is divided from the bottom of the dividing groove. The possibility of being destroyed is effectively reduced. For this reason, the reliability of deposition of the light absorbing layer on the mother substrate (individual insulating substrate) is also high.

  Accordingly, there is provided a multi-piece wiring board capable of manufacturing a wiring board for a light emitting device that can easily improve the light emission amount and suppress light reflection at the outer peripheral portion of the wiring board region and has high reliability. be able to.

(A) is sectional drawing which shows a part of multi-cavity wiring board of embodiment of this invention, (b) is sectional drawing which expands and shows the principal part of (a). It is a top view which shows an example of the whole multi-piece wiring board which shows a part in FIG. (A) is a top view showing an example of a wiring board manufactured by dividing the multi-cavity wiring board shown in FIG. 1 into individual pieces, and (b) is a sectional view taken along line AA in (a). is there. It is sectional drawing which shows the modification of the multi-piece wiring board shown in FIG. It is sectional drawing which shows the other modification of the multi-cavity wiring board shown in FIG.

  A multi-piece wiring board according to an embodiment of the present invention will be described with reference to the accompanying drawings. The light in the following description is visible light.

  FIG. 1A is a cross-sectional view showing a part of a multi-piece wiring board according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view showing an enlarged main part of FIG. . FIG. 2 is a plan view showing an example of the entire multi-cavity wiring board partially shown in FIG. A plurality of wiring board regions 2 are arranged vertically and horizontally on the mother board 1, and a dividing groove 3 is provided at the boundary of the wiring board area 2 so that a multi-piece wiring board 10 is basically configured. In FIG. 1, the boundary of the wiring board region 2 is indicated by a virtual line (two-dot chain line). A plurality of wiring board regions 2 are divided into individual wiring board regions 2 for each virtual line indicating the boundary position. Further, although FIG. 2 is not a cross-sectional view, the light absorbing layer 7 (described later) is hatched for easy understanding.

  The mother substrate 1 is formed of a ceramic sintered body such as an aluminum oxide sintered body or a glass ceramic sintered body. The mother board 1 may be formed by laminating a plurality of insulating layers (not shown) made of such a ceramic sintered body.

  If the mother board 1 is made of, for example, an aluminum oxide sintered body, it is manufactured as follows. First, a raw material powder containing aluminum oxide as a main component and added with additives (such as glass components) such as silicon oxide, calcium oxide and magnesium oxide is kneaded together with an organic solvent and a binder to prepare a slurry. Next, a plurality of ceramic green sheets are produced by forming the slurry into a sheet by a sheet forming technique such as a doctor blade method. Thereafter, the mother substrate 1 can be manufactured by firing a ceramic green sheet (or a laminate of a plurality of ceramic green sheets).

  The plurality of wiring board regions 2 arranged on the mother board 1 are areas that each become an individual wiring board. For example, a plurality of wiring boards 20 as shown in FIG. 3 are simultaneously and collectively manufactured by breaking and dividing the mother board 1 at the portion where the dividing grooves 3 are formed. The individual wiring substrate 20 includes an insulating substrate 21 obtained by dividing the mother substrate 1 and a light emitting element mounting portion 2 a provided at the center of the upper surface of the insulating substrate 21. The electronic component 30 is formed by mounting the light emitting element 4 on the wiring board 20. The electronic component 30 is used as a light emitting device for a backlight of a liquid crystal display device, for example. 3A shows an example of the wiring board 20 produced by dividing the multi-piece wiring board 10 shown in FIG. 1 into pieces and the electronic component 30 in which the light emitting element 4 is mounted on the wiring board 20. FIG. FIG. 3B is a cross-sectional view taken along line AA of FIG. In FIG. 3, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals. Although FIG. 3A is not a cross-sectional view, the light absorbing layer 7 (described later) is hatched for easy understanding.

  The dividing groove 3 is provided, for example, by cutting with a cutter blade or the like along the boundary of the wiring board region 2 on the upper surface of a ceramic green sheet (or a laminate of a plurality of ceramic green sheets) to be the mother board 1. Yes. The dividing groove 3 has a shape of a longitudinal section corresponding to the shape of the longitudinal section of the cutter blade or the like, and is, for example, a V-shape that gradually decreases in width from the opening to the bottom.

  By applying a stress such as a bending stress to the mother board 1 with the dividing groove 3 interposed therebetween, the mother board 1 is broken in the thickness direction starting from the bottom of the dividing groove 3, and the multi-piece wiring board 10 is separated into pieces. Divided into substrates 20.

  In the multi-piece wiring board 10 shown in FIG. 2, a dummy region 8 is provided on the outer periphery of the mother board 1. The dummy area 8 is provided to facilitate handling of the multi-piece wiring board 10. The boundary between the wiring board regions 2 is a boundary between the wiring board regions 2 and a boundary between the outermost wiring board region 2 and the dummy region 8. In this example, the dividing groove 3 is provided extending to the dummy region 8 (to the outer edge of the mother board 1), so that the mother board 1 can be divided more easily.

  As shown in FIG. 1 and FIG. 2, the light emitting element 4 is mounted on the central portion (mounting portion) 2 a of the upper surface of each of the plurality of wiring board regions 2 (individual pieces of wiring boards 20). The mounting of the light emitting element 4 may be performed in the state of the multi-piece wiring board 10 or after being divided into the individual wiring boards 20. FIG. 2 shows a state where the light emitting element 4 is not mounted on the mounting portion 2a.

  In the multi-cavity wiring board 10 of the embodiment, a recess (no symbol) is provided on the upper surface of the mother board 1 for each wiring board region 2. The inside of the recess is a central portion (mounting portion) 2a of the upper surface in each wiring board region 2, and the light emitting element 4 is mounted on the bottom surface of the recess. Further, on the upper surface of the mother board 1, a frame-shaped part surrounding the recess of each wiring board region 2 is the outer peripheral part 2 b.

Note that the mother substrate 1 is not limited to the one having the recesses as in the example of the present embodiment, and may be a flat plate (not shown) having no recesses on the upper surface. In the case of a flat mother board, the portion of the upper surface surrounding the portion where the light emitting element is mounted in each wiring board region and the portion where the wiring conductor (described later) electrically connected to the light emitting element is provided. The range is the central portion (mounting portion), and the outer side is the outer peripheral portion.

  The concave portion is formed by punching out a portion corresponding to the central portion of the wiring board region 2 in the thickness direction of the ceramic green sheet that is an upper layer when stacked, among the plurality of ceramic green sheets that become the mother substrate 1. 1 can be provided for each wiring board region 2 on the upper surface of 1.

  The light emitting element 4 mounted on the mounting portion 2a is provided, for example, from the mounting portion 2a to the lower surface of the mother board 1 in the wiring board region 2 including the mounting portion 2a (the lower surface of the insulating substrate 21 if it is a single piece). It is electrically led out to the lower surface through the wiring conductor 5. If a portion of the wiring conductor 5 provided on the lower surface of the wiring board region 2 is electrically connected to the external electric circuit, the light emitting element 4 is electrically connected to the external electric circuit via the wiring conductor 5. The light emitting element 4 is mounted on the central portion (mounting portion) 2a. For example, the electrode (not shown) of the light emitting element 4 is electrically connected to a portion of the wiring conductor 5 provided on the mounting portion 2a. It is performed by being electrically and mechanically connected via

  The light emitting element 4 may be mounted on the mounting portion 2a after the multi-piece wiring board 10 is divided into individual wiring boards 20 (mounting on individual wiring boards 20) or before being divided. Good. When the light emitting element 4 is mounted in each wiring board region 2 of the multi-cavity wiring board 10, for example, a multi-cavity electronic component as shown in FIG. 1A is manufactured. This multi-piece electronic component is divided along the dividing groove 3 to produce a plurality of pieces of electronic components.

  The wiring conductor 5 is formed of, for example, a metal material such as tungsten, molybdenum, manganese, copper, silver, palladium, gold, platinum, nickel or cobalt, or an alloy material containing at least one of these metal materials as a main component. ing. If the wiring conductor 5 is made of tungsten, for example, a metal paste prepared by kneading tungsten powder together with an organic solvent and a binder is printed on a ceramic green sheet serving as the mother board 1 in a predetermined pattern of the wiring conductor 5. The metal paste and the ceramic green sheet can be formed by co-firing. Further, a plating layer (not shown) such as nickel, cobalt, copper, silver or gold may be further deposited on the surface of the tungsten metallization layer. In consideration of light reflectance, the plating layer is preferably at least the uppermost layer is a silver plating layer, and in consideration of oxidation inhibition and solder wettability, at least the uppermost layer is preferably a gold plating layer. .

  The light emitting element 4 may be bonded to the bottom surface of the recess 2 via a bonding material such as an organic resin adhesive or a brazing material. In this case, the electrical connection between the electrode of the light emitting element 4 and the wiring conductor 5 is performed by, for example, a bonding wire (not shown).

  Electric power is supplied from the outside to the light emitting element 4 mounted on the mounting portion 2 a via the wiring conductor 5, and light is emitted by photoelectric conversion of the light emitting element 4. The light emitted from the light emitting element 4 is emitted to a certain part directly outward (upward), and the other part is reflected by the upper surface including the mounting portion 2a of the mother board 1 and emitted to the outside. .

The light emitting element 4 mounted on the mounting portion 2a is covered with a coating layer 6 made of a transparent resin material containing a fluorescent agent, for example. In the example of the embodiment, the covering layer 6 is filled inside the concave portion that is the central portion (mounting portion) 2 a of the wiring board region 2. In this case, the uncured resin material to be the coating layer 6 is filled in the concave portion so as to cover the light emitting element 4, and then the uncured resin material is cured to form the coating layer 6. be able to.

  The multi-cavity wiring board 10 of the embodiment is made of a dark color material, and is provided from the outer peripheral part 2b of the wiring board region 2 to the middle of the inner side surface of the dividing groove 3 in the height direction on the upper surface of the mother board 1. It has a light absorbing layer 7. The inside of the portion where the light absorbing layer 7 is provided is a light emitting element mounting portion 2a.

  Examples of the coloring material forming the light absorbing layer 7 include a dark pigment, a paint, or a material in which a dark pigment is added to a substrate such as a glass material or a ceramic material. In consideration of the strength of adhesion to the mother substrate 1 and long-term reliability, a coloring material in which a dark pigment is added to a base material such as a glass material is suitable as the coloring material. Details of this deposition and the like will be described later.

  The light absorption layer 7 is for suppressing reflection of light at the outer peripheral portion 2 b of the upper surface of the wiring board region 2. The light absorption layer 7 suppresses the light emitted from the light emitting element 4 from being reflected by the outer peripheral portion 2b. For example, when the electronic component 30 is used as a light emitting device for a backlight of a liquid crystal display device, The possibility that the outer peripheral portion is reflected on the liquid crystal display device is reduced.

  Therefore, the colorant has a dark color as described above, and is, for example, black, gray close to black, brown, dark blue, or dark green. A material containing such a dark pigment is used as a coloring material. These pigments preferably have a hue with a light reflectance of 10% or less. Examples of such pigments include cobalt and its oxide, chromium and trivalent chromium oxide, and manganese and its oxide.

  Since the light absorption layer 7 is provided on the outer peripheral portion, when the light emitting element 4 is mounted on the central portion (mounting portion 2a) of the wiring board region 2, the light in the central portion (mounting portion 2a) is transmitted. There is a low possibility that reflection is hindered by the light absorption layer 7. Therefore, the reflectance of the light of the mother board 1 in the mounting part 2a is high. Moreover, the reflection of the light in the outer peripheral part 2b of the outer side is suppressed effectively.

  Therefore, a multi-cavity wiring that can easily improve the amount of light emission as the light emitting electronic component 30 and suppress the reflection of light at the outer peripheral portion of the upper surface of the wiring board region 2a (the insulating substrate 21 of the piece of wiring board 20). A substrate 10 can be provided.

  Further, the light absorption layer 7 is provided halfway in the height direction of the inner surface of the dividing groove 3 and does not reach the bottom of the dividing groove 3. Therefore, the possibility that the light absorbing layer 7 is mechanically broken when the mother substrate 1 is divided (broken) from the bottom of the dividing groove 3 is effectively reduced. Therefore, the reliability of adhesion of the light absorption layer 7 to the mother substrate 1 (individual insulating substrate 21) is also high. Therefore, it is also possible to provide a multi-piece wiring board capable of manufacturing the highly reliable electronic component 30 (light emitting device).

  The dividing groove 3 in which the light absorption layer 7 is provided up to the middle of the inner surface in the height direction is provided between the wiring substrate regions 2 and between the wiring substrate region 2 and the dummy region 8. Including those provided. Further, when the dividing groove 3 is extended into the dummy region 8 as in the example of FIG. 2, the extended portion is also included. That is, when the mother substrate 1 is broken along the dividing groove 3 in the thickness direction, the light absorbing layer 7 (coloring material) that is likely to be mechanically damaged is not attached to the bottom of the dividing groove 3 and the vicinity thereof. .

  As the colorant forming the light absorption layer 7, for example, a glass material or a ceramic material to which a dark pigment is added as described above is used.

The pigment content in the light absorbing layer 7 is preferably such an amount that the reflectance of light on the exposed surface of the light absorbing layer 7 is about 20% or less. For example, when the pigment is an oxide of cobalt or manganese, it is preferably about 5 to 20% by mass.

  The pigment contained in the light-absorbing layer 7 is dark as described above, but is preferably black in terms of suppressing light reflection. Examples of the black pigment include the above cobalt, chromium, manganese, and oxides thereof.

  As described above, the coloring material forming the light absorbing layer 7 may be made of a glass material containing a pigment. The glass material in this case functions as a base material for the colorant, and serves as a base material on which the colorant containing the pigment is deposited on the surface of the mother substrate 1.

  In this case, it is easy to color the glass material to a color (black or the like) suitable for suppressing light reflection with a pigment. Further, the glass material can be easily deposited on the upper surface of the wiring board region 2 a by simultaneous firing with the mother board 1. Therefore, it is possible to produce a coloring material having a high adhesion strength to the mother substrate 1 and easy to be colored, and a multi-piece wiring substrate in which the light absorption layer 7 and the reliability of the adhesion to the mother substrate 1 are higher. Can be 10.

  The colorant made of a glass material containing a pigment is deposited on the mother substrate 1 by simultaneous firing with the mother substrate 1 in the following manner, for example. That is, a powder of cobalt oxide, which is a pigment, and a glass powder such as silica glass are kneaded together with an appropriate organic solvent and a binder to produce a coloring paste, and this coloring paste is used as a ceramic as a mother substrate 1. The ceramic green sheet and paste are integrally fired integrally after being applied to a predetermined portion of the surface of the green sheet. Thereby, the light absorption layer 7 made of a coloring material can be provided at a predetermined site on the surface of the mother substrate 1. As said glass powder, what is the glass component similar to the glass component contained in the mother substrate 1 is mentioned. If the glass materials contained between the coloring material (light absorption layer 7) and the mother substrate 1 are the same as each other, it is more advantageous in improving the bonding strength between the light absorption layer 7 and the mother substrate 1. is there.

  In order to provide the coloring material to be the light absorption layer 7 in the middle of the inner surface of the dividing groove 3 in the height direction, for example, the bottom portion of the dividing groove 3 is previously filled with an organic resin material that can be thermally decomposed during firing. Then, the coloring paste may be printed on the surface of the ceramic green sheet to be the mother substrate 1 as described above. At this time, the paste is not applied to the bottom portion of the dividing groove 3 because it is hindered by the organic resin material. Thereafter, if the ceramic green sheet, paste and organic resin material are fired at the same time, the organic resin material is decomposed and removed, and the coloring material is applied to the middle of the inner side surface of the dividing groove 3 to form the light absorption layer 7. Is done.

  It is preferable that the organic resin material previously filled in the bottom portion of the dividing groove 3 is only one whose components are removed as a gas along with thermal decomposition. Examples of such organic resin materials include hydrocarbon resin materials such as polypropylene and polyethylene. In addition, these organic resin materials can be filled in the bottom part of the division groove | channel 3 in the state melt | dissolved in the organic solvent, for example in the heat melting.

  The glass material preferably contains boron oxide and barium oxide in addition to the silicon oxide (silica) component as the base material. In this case, since the boron oxide and the barium oxide each have an effect of assisting the sintering or bonding of the pigment component and the glass component, the pigment and the glass material are more firmly bonded in the coloring material (for example, The mutual sinterability at the time of firing can be improved).

The coloring material forming the light absorbing layer 7 is not necessarily applied to the mother substrate 1 by simultaneous firing with the mother substrate 1. For example, a glass material powder having a softening temperature lower than that of the glass material contained in the mother substrate 1 and a pigment powder are kneaded together with an organic solvent, a binder, and the like at a predetermined position on the surface of the mother substrate 1 after firing. The light-absorbing layer 7 may be formed by preparing a paste for coloring material and applying the paste to the surface of the mother substrate 1 and then melting the glass powder once by heating, followed by cooling and solidification.

  Further, in the multi-piece wiring board 10 (piece wiring board) of the embodiment, the inner peripheral position of the light absorption layer 7 and the outer peripheral position of the mounting portion 2a overlap each other. In this case, reflection of light from the outer side (outer peripheral part 2b) can be effectively suppressed while effectively improving the reflectance of light to the outside in the mounting part 2a. Therefore, it is possible to provide a multi-piece wiring board 10 capable of manufacturing an electronic component 30 (light emitting device) that is more advantageous in both the light emission amount and the suppression of light reflection at the outer peripheral portion.

  FIG. 4 is a sectional view showing a modification of the multi-cavity wiring board 10 shown in FIG. 4, parts similar to those in FIG. 1 are denoted by the same reference numerals. In the example shown in FIG. 4, the thickness of the light absorption layer 7 on the inner surface of the dividing groove 3 is gradually reduced at the end portion.

  In this case, since the thickness at the tip portion of the light absorbing layer 7 is thin, the tip portions of the light absorbing layer 7 provided on the inner side surfaces of the two inner side surfaces of the dividing groove 3 facing each other are arranged. The possibility of being connected is reduced more effectively. Therefore, for example, the portion where the tips of the light absorbing layer 7 are connected to each other is prevented from being mechanically broken when the mother substrate 1 is broken.

  In order to reduce the thickness of the end portion of the inner surface of the dividing groove 3 for the light absorption layer 7, for example, when applying a coloring paste to be the light absorption layer 7, the viscosity of the paste is made relatively small and the application thickness is reduced. You may adjust it.

  FIG. 5 is a cross-sectional view showing another modification of the multi-cavity wiring board 10 shown in FIG. 5, parts similar to those in FIG. 1 are denoted by the same reference numerals. In the example shown in FIG. 5, the inner surface of the dividing groove 3 is curved in a convex shape. In other words, the width of the dividing groove 3 (the dimension in the direction orthogonal to the length direction of the dividing groove 3 in a top view) is relatively large in the portion close to the opening of the dividing groove 3 and suddenly decreases as it approaches the bottom portion. It has become. In this example, most of the portion of the inner surface of the dividing groove 3 that can be seen in the top view is occupied by the portion close to the opening of the dividing groove 3. Further, the light absorption layer 7 is provided only on the inner surface of the dividing groove 3 near the opening of the dividing groove 3.

  In this case, since the light absorbing layer 7 is provided only in the portion close to the opening of the dividing groove 3, there is a possibility that the coloring paste that becomes the light absorbing layer 7 is mistakenly applied to the bottom of the dividing groove 3. It has been reduced more. Therefore, mechanical destruction of the light absorption layer 3 when the mother substrate 1 is divided can be more effectively suppressed. Moreover, the range in which the light-absorbing material 7 is provided in the plan view of the wiring board region 2 is also sufficiently wide.

  To form the dividing groove 3 as shown in FIG. 5, for example, when forming the dividing groove 3 on the ceramic green sheet to be the mother substrate 1, the vertical sectional shape of the cutter blade to be used is matched with the shape of the dividing groove 3. Or the elastic modulus of the ceramic green sheet to be the mother substrate 1 may be adjusted. The larger the elastic modulus of the ceramic green sheet, the larger the elastic deformation (return) of the ceramic green sheet at the bottom portion of the dividing groove 3 after the cutter blade is pulled out, and the width of the dividing groove 3 abruptly decreases at the bottom portion.

Note that the multi-piece wiring board of the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention. For example, for the light absorption layer 7,
The surface roughness of the exposed surface such as the upper surface is made rougher than the surface roughness of the mother substrate 1 so that the amount of light reflected upward (that is, the direction of the liquid crystal screen or the like) is further reduced. Good. As a method of increasing the surface roughness of the light absorbing layer 7, for example, a method of performing a surface roughening treatment such as etching or sand blasting on the colorant deposited on the surface of the mother substrate 1 as the light absorbing layer 7 is used. Can be mentioned.

DESCRIPTION OF SYMBOLS 1 ... Mother board 2 ... Wiring board area | region 2a ... Center part (mounting part)
2b ... outer peripheral part 3 ... dividing groove 4 ... light emitting element 5 ... wiring conductor 6 ... coating layer 7 ... light absorption layer 8 ... dummy region
10 ... Multi-piece wiring board
20 ... wiring board
21 ・ ・ ・ Insulating substrate
30 ... Electronic components

Claims (6)

A plurality of wiring board regions are arranged, and the light emitting element mounting portion provided at the center of each of the plurality of wiring board regions, and each of the plurality of wiring board regions. A mother substrate having an upper surface including a dividing groove provided along the boundary;
A light-absorbing layer made of a dark colorant and provided from the outer peripheral part of the upper surface of the mother board outside the central part of the wiring board region to the middle of the inner side surface of the dividing groove. A multi-cavity wiring board characterized by comprising. 2. The multi-cavity wiring board according to claim 1, wherein the colorant is black. 2. The multi-cavity wiring board according to claim 1, wherein the colorant is made of a glass material containing a dark pigment. 2. The multi-cavity wiring board according to claim 1, wherein an inner peripheral position of the light absorption layer and an outer peripheral position of the mounting portion overlap each other. 5. The wiring board according to claim 1, wherein the plurality of wiring board regions included in the multi-cavity wiring board according to claim 1 are divided into pieces. The wiring board according to claim 5;
An electronic component comprising: a light emitting element mounted on the mounting portion.

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