JP2014127678A - Wiring board and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board capable of suppressing disconnection in a conductor layer part and an increase in electrical resistance of the conductor layer part.SOLUTION: A wiring board 1 includes: an insulating base 11 having an insulating layer 11a; a wiring conductor 14 provided on a main surface of the insulating layer 11a; and a conductor layer part connected to the wiring conductor 14. The insulating base 11 includes the insulating layer 11a which has a castellation part 12 extending in a vertical direction, and the castellation part 12 has a groove extending in the vertical direction. The conductor layer part is provided in the castellation part 12 so as to enter the groove.

Description

  The present invention relates to a wiring board and an electronic device.

  For example, a wiring board used for mounting electronic components is provided on an insulating substrate including an insulating layer, a wiring conductor provided on the main surface of the insulating layer (that is, the main surface or the inner layer of the insulating substrate), and a side surface of the insulating layer. And a conductor layer portion formed. The insulating layer has a castellation portion extending in the vertical direction, and the conductor layer portion is provided in the castellation portion. For example, when the insulating substrate is made of ceramics, the conductor layer portion of the castellation portion is formed by applying a conductor paste to a ceramic green sheet and firing it (see, for example, Patent Document 1).

  The above-described wiring board may be manufactured by dividing a multi-piece wiring board from the viewpoint of manufacturing efficiency due to the recent miniaturization of electronic devices. A multi-cavity wiring board is one in which a plurality of wiring board regions are arranged vertically and horizontally.

JP 2010-232687

  About the conductor layer part in a castellation part, it may be difficult to form in sufficient thickness compared with the wiring conductor in the main surface of an insulating layer. When the conductor layer portion does not have a sufficient thickness, there is a concern about disconnection in the conductor layer portion or an increase in electrical resistance in the conductor layer portion.

  In addition, when the wiring board is manufactured by dividing, for example, a multi-piece wiring board and the insulating base is made of ceramics, for example, the conductor layer part of the castellation part is formed on the inner surface of the through hole provided in the ceramic green sheet, for example. The conductive layer may be formed by applying a conductive paste and firing. In this forming method, it may be difficult to form the conductive layer portion with a sufficient thickness to the depth of the through hole.

  According to one aspect of the present invention, the wiring board includes an insulating base having an insulating layer, a wiring conductor provided on the main surface of the insulating layer, and a conductor layer portion connected to the wiring conductor. The insulating base includes an insulating layer having a castellation portion extending in the vertical direction, and the castellation portion has a groove portion extending in the vertical direction. The conductor layer portion is provided in the castellation portion so as to enter the groove portion.

  According to another aspect of the present invention, an electronic device includes the wiring board having the above configuration and an electronic component mounted on the wiring board.

In the wiring board according to one aspect of the present invention, the castellation portion has a groove portion extending in the vertical direction, and the conductor layer portion is provided in the castellation portion so as to enter the groove portion. A sufficient thickness can be ensured in at least a part of the portion, and disconnection in the conductor layer portion and an increase in electric resistance in the conductor layer portion can be suppressed.

  An electronic device according to another aspect of the present invention is improved in terms of electrical reliability and electrical characteristics by including the wiring board having the above configuration.

(A) is a top view which shows the wiring board in the 1st Embodiment of this invention, (b) is a bottom view of (a). (A) is sectional drawing in the AA line of the wiring board shown by Fig.1 (a), (b) is sectional drawing in the BB line of the wiring board shown in Fig.1 (a). is there. (A)-(d) is sectional drawing which shows the 1st manufacturing method of the conductor layer of the wiring board in the 1st Embodiment of this invention. (A)-(f) is sectional drawing which shows the 2nd manufacturing method of the conductor layer of the wiring board in the 1st Embodiment of this invention. (A)-(f) is sectional drawing which shows the 3rd manufacturing method of the conductor layer of the wiring board in the 1st Embodiment of this invention. (A) is a top view which shows the wiring board in the 2nd Embodiment of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows the wiring board in the 1st Embodiment of this invention, (b) is a bottom view of (a). FIG. 1A is an enlarged bottom view of a main part of the wiring board A shown in FIG. 1B, and FIG. 1B is a cross-sectional view taken along the line AA of the wiring board shown in FIG. It is.

  Several exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
The electronic device according to the first embodiment of the present invention includes a wiring board 1 and an electronic component 2 provided on the upper surface of the wiring board 1 as shown in FIGS. 1 and 2. The electronic device is mounted on a circuit board that constitutes an electronic component module, for example.

  The wiring substrate 1 includes an insulating substrate 11 having a castellation portion 12 extending in the vertical direction, a conductor layer portion (conductor layer 13) provided in the castellation portion, and an insulating substrate electrically connected to the conductor layer 13 11 and a wiring conductor 14 provided on the surface and inside. The castellation portion 12 has a groove portion (groove 12a) extending in the vertical direction, and the conductor layer 13 enters the groove 12a. 1 and 2, the electronic device is mounted on an xy plane in a virtual xyz space. 2 to 5, the upward direction refers to the positive direction of the virtual z axis.

  The insulating base 11 is composed of a plurality of insulating layers 11a, has an upper surface including a mounting area for the electronic component 2, and has a rectangular plate shape in plan view. The insulating substrate 11 functions as a support for supporting the electronic component 2, and the electronic component 2 is bonded and fixed to the mounting area in the center of the upper surface via a bonding agent such as a low melting point brazing material or a conductive resin. The

  As the insulating substrate 11, for example, ceramics such as an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, or a glass ceramic sintered body can be used.

When the insulating substrate 11 is manufactured using a resin material, for example, an epoxy resin, a polyimide resin, an acrylic resin, a phenol resin, a polyester resin, or a fluorine resin such as a tetrafluoroethylene resin is used. Can do.

  If the insulating substrate 11 is made of, for example, an aluminum oxide sintered body, a suitable organic binder and solvent are added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide and calcium oxide to form a slurry. Then, this is formed into a sheet shape by the doctor blade method or the calender roll method to obtain a ceramic green sheet. After that, the ceramic green sheet is subjected to appropriate punching processing, and a plurality of these are laminated to obtain a high temperature (about 1600 Manufactured by baking at a temperature of ° C.

  The castellation unit 12 is provided on the side surface of the insulating base 11. The castellation portion 12 may be provided from one main surface to the other main surface of the insulating base 11, or as shown in FIG. 2 from the middle of the side surface of the insulating base 11 to the main surface. It doesn't matter. Such a castellation part 12 is formed by forming through holes to be the castellation part 12 in some of the ceramic green sheets for the insulating substrate 11 by laser machining or punching with a mold. The

  The conductor layer 13 is provided on the inner surface of the castellation portion 12, and the wiring conductor 14 is provided on the surface and inside of the insulating base 11. A part of the wiring conductor 14 is led out to the castellation portion 12 and is electrically connected to the conductor layer 13. The conductor layer 13 and the wiring conductor 14 are for electrically connecting the electronic component 2 mounted on the wiring board 1 and an external circuit board. The wiring conductor 14 includes a wiring conductor provided on the surface of or inside the insulating base 11, and a penetrating conductor that penetrates the insulating layer constituting the insulating base 11 and electrically connects the wiring conductors positioned above and below. It is out.

  For the conductor layer 13 and the wiring conductor 14, a metal material such as tungsten (W), molybdenum (Mo), manganese (Mn), silver (Ag), or copper (Cu) can be used. For example, when the insulating substrate 11 is made of an aluminum oxide sintered body, a conductive paste obtained by adding and mixing a suitable organic binder and solvent to a refractory metal powder such as W, Mo or Mn is insulated. The ceramic green sheet to be the base 11 is preliminarily printed and applied in a predetermined pattern by a screen printing method, and is fired simultaneously with the ceramic green sheet to be the insulating base 11, thereby being deposited on a predetermined position of the insulating base 11. When the wiring conductor 14 is a through conductor, a through hole is formed in the green sheet by punching by a die or punching or laser processing, and a conductive paste for the wiring conductor 14 is filled into the through hole by a printing method. It is formed by placing. The conductor layer 13 is formed by printing and applying a conductor paste for the conductor layer 13 in a region that becomes the inner surface of the through hole that becomes the castellation portion 12.

The thin film layer 15 is provided so as to overlap the wiring conductor 14 of the insulating base 11. The thin film layer 15 can be made of a metal material such as tungsten (W), molybdenum (Mo), titanium (Ti), or copper (Cu). The thin film layer 15 is composed of a plurality of layers, for example, made of a Ti alloy such as TiW (titanium tungsten), and has a thickness of, for example, 0.01 to 0.5 μm and Cu (copper), and has a thickness of, for example, 1.0 to 100.0 μm. Have

  The thin film layer 15 is formed by using a conventionally well-known thin film forming method such as an ion plating method, a sputtering method, or a vapor deposition method. For example, a metal layer is formed on the surface of the insulating substrate 11 by ion plating, sputtering, vapor deposition, or the like. Thereafter, a resist pattern is formed by photolithography, and an excess metal layer is removed by wet etching.

The groove 12a is provided in the castellation portion 12 so as to extend in the vertical direction, and the conductor layer 13 is provided so as to enter the groove 12a. In the region of the groove 12a, the conductor layer 13 is formed thicker than the other regions, and is disposed so as to be in direct contact with and overlap the wiring conductor 14 at least in a plan view. In this way, when the thickness of the conductor layer 13 on the inner surface of the castellation part 12 is partially thickened, for example, compared to the case where the thickness of the conductor layer 13 is formed thick on the entire inner surface of the castellation part 12, Since the shape of the castellation portion 12 and the shape of the conductor layer 13 can be formed as good, the wiring board can be made small and highly accurate, and the connection with the external circuit board is good. can do. If the width of the wiring conductor 14 led out from the inside of the insulating base 11 to the castellation portion 12 in plan view is made larger than the width of the groove 12a, the conductor layer 13 and the wiring conductor 14 are overlapped. The connection with can be made good.

  Formation of the conductor layer 13 in the castellation part 12 and the groove 12a can be manufactured by the following manufacturing method, for example.

In the first manufacturing method, as in the example shown in FIG. 3A, the through-hole 112 serving as the castellation portion 12 having the groove 12a is formed in the ceramic green sheet 111 for the insulating base 11. Then, as in the example shown in FIG. 3 (b), the castellation portion 12 and the conductor paste for the conductor layer 13 are inserted into the groove 112 by the screen printing method in the region to be the inner surface of the through hole 112. Application printing is performed on the inner surface of the through-hole 112. Then, the conductor paste for the wiring conductor 14 is printed, laminated with other ceramic green sheets, etc., and the ceramic that becomes the insulating base 11 in which the conductor paste for the conductor layer 13 and the conductor paste for the wiring conductor 14 are connected By forming the formed body and firing the ceramic molded body, the insulating base 11 connected to the castellation portion 12 is formed as in the example shown in FIG. Further, as in the example shown in FIG. 3D, the wiring substrate 1 in which the conductor layer 13 is formed in the castellation portion 12 having the groove 12a by dividing the hole 112b that becomes the castellation portion 12 is obtained. Can be produced.

Next, in the second manufacturing method, as in the example shown in FIG. 4A, the auxiliary through hole 112a to be the groove 12a is formed in the ceramic green sheet 111 for the insulating base 11. Then, as in the example shown in FIG. 4B, the conductor paste for the conductor layer 13 is printed and applied to the inner surface of the auxiliary through hole 112a by the screen printing method. Then, as in the example shown in FIG. 4C, the first through hole 112a is divided, and the conductive paste for the conductor layer 13 filled in the groove 12a in the ceramic green sheet 111 for the insulating substrate 11 is obtained. Is exposed, and a through-hole 112 serving as a castellation portion 12 having a groove 12a is formed. Then, as in the example shown in FIG. 4D, the conductor layer 13 in which the conductor paste for the conductor layer 13 is applied to the inner surface of the groove 12a by the screen printing method in the region serving as the inner surface of the through hole 112. Application printing is performed on the inner surface of the through-hole 112 serving as the castellation portion 12 so as to cover the conductive paste for use. After that, the conductor paste for the wiring conductor 14 is printed, laminated with another ceramic green sheet, etc., and the ceramic that becomes the insulating base 11 in which the conductor paste for the conductor layer 13 and the conductor paste for the wiring conductor 14 are connected By forming the formed body and firing the ceramic molded body, the insulating base 11 connected to the castellation portion 12 is formed as in the example shown in FIG. Further, as in the example shown in FIG. 4F, the wiring substrate 1 in which the conductor layer 13 is formed in the castellation portion 12 having the groove 12a by dividing the hole 112b that becomes the castellation portion 12 is obtained. Can be produced.

In the third manufacturing method, as in the example shown in FIG. 5A, the auxiliary through hole 112a to be the groove 12a is formed in the ceramic green sheet 111 for the insulating base 11. Then, as in the example shown in FIG. 5 (b), the conductor paste for the conductor layer 13 is coated with the auxiliary through holes 112 by screen printing.
Fill the inner surface of a. Then, as in the example shown in FIG. 5C, the first through-hole 112a is divided, and the conductor layer 13 filled in the groove 12a is formed in the ceramic green sheet 111 for the insulating base 11.
The conductive paste for use is exposed, and a through-hole 112 serving as a castellation portion 12 having a groove 12a is formed. Then, as in the example shown in FIG. 5D, the conductor layer 13 for the conductor layer 13 in which the conductor paste for the conductor layer 13 is filled in the groove 12a by the screen printing method in the region which becomes the inner surface of the through hole 112. Coating and printing are performed on the inner surface of the through-hole 112 serving as the castellation portion 12 so as to cover the conductor paste. After that, the conductor paste for the wiring conductor 14 is printed, laminated with another ceramic green sheet, etc., and the ceramic that becomes the insulating base 11 in which the conductor paste for the conductor layer 13 and the conductor paste for the wiring conductor 14 are connected By forming the formed body and firing the ceramic molded body, the insulating base 11 connected to the castellation portion 12 is formed as in the example shown in FIG. Further, as shown in the example shown in FIG. 5 (f), after firing this ceramic shaped body, the hole 112b that becomes the castellation portion 12 is divided to form a conductor layer on the castellation portion 12 having the groove 12a. The wiring board 1 on which 13 is formed can be manufactured.

  The first manufacturing method can be suitably used when the length of the groove 12 a in plan view (the length from the castellation portion 12 to the central portion of the insulating base 11) is smaller than the thickness of the conductor layer 13. For example, it is used when the length of the groove 12a is 5 μm to 50 μm.

  In the first manufacturing method, when the conductor layer 13 is formed on the inner surface of the castellation portion 12, the conductor layer 13 is integrally formed so as to enter the groove 12a. Since joining to the conductor layer 13 and peeling of the conductor layers 13 are unlikely to occur, it is preferable when a plurality of grooves 12a as described later are formed. Further, since the groove 12a is formed to be small, it can be suitably used for a small-sized wiring board.

  The third manufacturing method can be suitably used when the length of the groove 12a in plan view (the length from the castellation portion to the central portion of the insulating base 11) is larger than the thickness of the conductor layer 13. For example, it is used when the length of the groove 12a is 50 μm to 200 μm.

  In the third manufacturing method, when the size of the castellation portion 12 is small in plan view or the depth of the castellation portion 12 is deep, the metal layer when forming the thin film layer 15 on the surface of the conductor layer 13 is formed. It is preferably used when it is more difficult to form or when the thin film layer 15 is formed thick.

A plating layer is deposited on the exposed surfaces of the conductor layer 13, the wiring conductor 14, and the thin film layer 15 by an electrolytic plating method. The plating layer is made of a metal having excellent corrosion resistance such as nickel, copper, gold, or silver, and connectivity with a connection member. For example, a nickel plating layer having a thickness of about 0.5 to 5 μm and a gold plating having a thickness of about 0.1 to 3 μm. A nickel plating layer having a thickness of about 1 to 10 μm and a silver plating layer having a thickness of about 0.1 to 1 μm are sequentially deposited. As a result, the conductor layer 13, the wiring conductor 14, and the thin film layer 15 can be effectively prevented from corroding, and the connection between the wiring conductor 14 and the electronic component 2 and the connection member 3 such as the wiring conductor 14 and the bonding wire can be reduced. And the bonding of the conductor layer 13, the wiring conductor 14, and the thin film layer 15 to the wiring of the external circuit board can be strengthened. Further, on the wiring conductor 14 on which the electronic component 2 is to be mounted, a copper plating layer having a thickness of about 10 to 80 μm is deposited on the nickel plating layer, so that the heat of the electronic component 2 can be dissipated well. It may be easier.

An electronic device can be manufactured by mounting the electronic component 2 on the upper surface of the wiring board 1. The electronic component 2 mounted on the wiring board 1 is a semiconductor element such as an IC chip or an LSI chip, a light emitting element, a piezoelectric element such as a crystal vibrator or a piezoelectric vibrator, and various sensors. For example, when the electronic component 2 is a flip-chip type semiconductor element, the semiconductor element is connected to the semiconductor element via a connection member 3 such as a solder bump, a gold bump, or a conductive resin (anisotropic conductive resin). These electrodes and the wiring conductor 14 are mounted on the wiring board 1 by being electrically and mechanically connected. For example, when the electronic component 2 is a wire bonding type semiconductor element, the semiconductor element is fixed to the electronic component mounting region by a bonding member, and then the electrode of the semiconductor element is connected via a connection member 3 such as a bonding wire. And the wiring conductor 14 are mounted on the wiring substrate 1 by being electrically connected. In addition, a plurality of electronic components 2 may be mounted on the wiring board 1, or small electronic components such as a resistance element and a capacitive element may be mounted as necessary. Further, the electronic component 2 is sealed with a sealing material 4 made of resin, glass, or the like, a lid made of resin, glass, ceramics, metal, or the like, as necessary.

  According to the wiring board 1 of the present embodiment, the insulating substrate 11 includes the insulating layer 11a having the castellation portion 12 extending in the vertical direction, and the castellation portion 12 has the groove 12a extending in the vertical direction. And the wiring conductor 14 provided on the main surface of the insulating layer 11a, and provided in the castellation portion 12 so as to enter the groove 12a, and the conductor 13 connected to the wiring conductor 14, A sufficient thickness can be ensured in at least a part of the conductor layer portion, and disconnection in the conductor layer portion and an increase in electrical resistance in the conductor layer portion can be suppressed.

  The wiring board 1 of this embodiment is suitably used for a wiring board using a metal material such as tungsten or molybdenum for the conductor layer 13 and the wiring conductor 14 and using a metal material such as titanium tungsten for the thin film layer 15, and has high accuracy. And it can be set as the wiring board excellent in reliability. For example, when a metal layer for forming the thin film layer 15 is formed on the insulating substrate 11, the metal layer at the back of the castellation portion 12 is easily formed thinner than the metal layer on the surface of the insulating base 11. For this reason, when removing the excess metal layer by etching, the conductor layer 13 is removed by etching after the metal layer at the back of the castellation portion 12 is removed before the surface of the insulating base 11. Even if the thickness of the conductor layer 13 in the deep part of the castellation part 12 is reduced, the electrical connection between the conductor layer 13 and the wiring conductor 14 in the groove 12a is maintained. An increase in electrical resistance in the layer portion can be suppressed.

  According to the electronic device of the present embodiment, since the wiring board 1 having the above-described configuration and the electronic component 2 mounted on the wiring board 1 are provided, the electrical reliability and the electrical characteristics are improved. .

(Second Embodiment)
Next, an electronic device according to a second embodiment of the present invention will be described with reference to FIG.

  The electronic device according to the second embodiment of the present invention differs from the electronic device according to the first embodiment described above in that the castellation section 12 has a plurality of grooves 12a as in the example shown in FIG. The thin film layer 15 is provided on the same main surface as the mounting surface of the electronic component 2 of the insulating base 11. In such a case, since it can be bonded to an external circuit board on the upper surface side of the wiring board 1, a member having a higher thermal conductivity than the insulating base 11 is bonded to the entire lower surface side of the wiring board 1. Can improve heat dissipation. Examples of the material having higher thermal conductivity than the insulating base 11 include metal materials such as copper (Cu), copper-tungsten (Cu-W), and aluminum (Al). When the insulating base 11 is made of an aluminum oxide sintered body, an insulating material made of an aluminum nitride sintered body can be used.

  In addition, when the width of the wiring conductor 14 led out from the inside of the insulating base 11 to the castellation portion 12 in plan view is formed so as to overlap the whole of the plurality of grooves 12a, the conductor layer 13 and the wiring conductor 14 In addition, it is possible to make the wiring board excellent in reliability by suppressing the occurrence of a step between the grooves 12a.

Note that the insulating substrate 11 may have an upper surface including the recess 16 as in the example shown in FIG. Such recesses 16 are formed in a plurality of ceramic green sheets through holes that become the recesses 16 by laser processing or punching with a mold on the ceramic green sheets, and these ceramic green sheets are formed as through holes. It can be formed by laminating the ceramic green sheets. In addition, when the insulating substrate 11 is thin, it is preferable that the through hole for the recess 16 is formed by laser processing or punching with a mold after laminating ceramic green sheets, because it can be processed with high accuracy.

  When the recess 16 is a space for mounting a light emitting element, the angle θ formed by the inner surface of the recess 16 and the bottom surface of the recess 16 is an obtuse angle, as in the example shown in FIG. 110 degrees to 145 degrees is preferable. When the angle θ is in such a range, it is easy to stably and efficiently form the inner surface of the through hole that becomes the recess 15 by punching, and the light emitting device using the wiring substrate 1 can be easily downsized. In addition, the light emitted from the light emitting element can be emitted well toward the outside. The concave portion 16 having the inner surface with such an angle θ is formed by punching the ceramic green sheet using a punching die in which the clearance between the punch diameter and the die hole diameter is set large. In other words, by setting the clearance of the die hole diameter larger than the punch diameter of the punching die, the green sheet is punched when the ceramic green sheet is punched from the main surface side to the other main surface side. Is formed so that the diameter of the through hole spreads from the main surface side to the other main surface side by shearing from the edge of the contact surface to the edge of the contact surface with the die hole. At this time, the angle of the inner surface of the through hole formed in the ceramic green sheet can be adjusted by setting the clearance between the diameter of the punch and the diameter of the die hole according to the thickness of the ceramic green sheet. Such a punching method is highly productive because the angle θ formed by the inner surface of the recess 16 and the bottom surface of the recess 16 can be set to a desired angle only by punching.

  In addition, after forming a through hole having an angle θ of about 90 degrees by processing with a punching die having a small clearance between the diameter of the punch and the diameter of the die, a truncated cone shape or a truncated pyramid shape is formed on the inner surface of the through hole. A through-hole having an angle θ extending from one main surface side to the other main surface side as described above may be formed by pressing the mold. In such a case, the angle θ formed by the inner surface of the recess 16 and the bottom surface of the recess 15 can be adjusted with higher accuracy.

  When the wiring substrate 1 has an insulating base 11 having an upper surface including a recess 16 on which the light emitting element is mounted, for example, a reflection layer for reflecting light emitted from the light emitting element is provided on the inner wall surface of the recess 15. It may be done. The reflective layer has, for example, a metal conductor layer provided on the inner wall surface of the recess 16 and a plating layer deposited on the metal conductor layer. The metal conductor layer can be formed by the same material and method as the conductor layer 13 and the wiring conductor 14.

  For example, when a light emitting element is mounted on the wiring board 1, a silver plating layer is deposited on the outermost surface of the metal conductor layer, and a gold plating layer is deposited on the outermost surfaces of the conductor layer 13 and the wiring conductor 14. It is preferable. Compared with the silver plating layer, the gold plating layer is superior in bonding properties to the electronic component 2, the connection member 3, and the wiring of the external circuit board. The silver plating layer is more resistant to light than the gold plating layer. This is because the reflectance is high. Further, the outermost surfaces of the wiring conductor 14 and the metal conductor layer may be an alloy plating layer of silver and gold, for example, an alloy plating layer that is a solid solution of silver and gold.

(Third embodiment)
Next, an electronic device according to a third embodiment of the present invention will be described with reference to FIGS.

  The electronic device according to the third embodiment of the present invention differs from the electronic device according to the above-described embodiment in that the inner wall surface of the castellation portion 12 is seen in a plan view as in the examples shown in FIGS. In the point which has the several groove | channel 12a formed in the waveform, the conductor layer 13 is spaced apart from the outer wall of the wiring board 1, and the thin film layer 15 is provided in the upper surface and lower surface of the insulation base | substrate 11. is there.

  In such a wiring board 1, the connection between the conductor layer 13 and the wiring conductor 14 can be improved particularly in a small-sized wiring board.

  In addition, when the width of the wiring conductor 14 led out from the inside of the insulating base 11 to the castellation portion 12 in plan view is formed so as to overlap the whole of the plurality of grooves 12a, the conductor layer 13 and the wiring conductor 14 Connection can be made good.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. Further, as in the example shown in FIGS. 7 and 8, the wiring board 1 may include conductors other than wiring such as the electronic component mounting layer 17 and the central terminal 18. For example, these conductors can be manufactured by the same material and method as the above-described wiring conductor 14 and thin film layer 15, and the exposed surface is plated by the same method as the conductor layer 13, wiring conductor 14 and thin film layer 15. The layer is applied. The electronic component mounting layer 17 is used, for example, for mounting the electronic component 2, and the central terminal 18 is used for bonding to an external circuit board, for example, like the conductor layer 13.

  Further, the wiring board 1 has a through hole formed in the insulating base, and a metal member having better heat dissipation than the insulating base 11 on which the electronic component 2 is mounted is fitted into the through hole and joined to the insulating base. In the wiring board 1 or the insulating substrate 11, a metal member having better heat dissipation than the insulating substrate 11 is embedded in a region overlapping the region where the electronic component 2 is mounted in plan view. Also good.

  Further, the wiring board 1 may be manufactured in the form of a multi-piece wiring board.

1 ... Wiring board
11 ... Insulating substrate
11a ... Insulating layer
12 ... Castellation part
12a ... Groove
13 ... Conductor layer
14 ... Wiring conductor
15 ... Thin film layer
16 ... Recess
17 ... Electronic component mounting layer
18 ... Central terminal layer 2 ... Electronic component 3 ... Connection member 4 ... Sealing material

Claims (4)

Including an insulating layer having a castellation portion extending in the vertical direction, the castellation portion having a groove portion extending in the vertical direction;
A wiring conductor provided on the main surface of the insulating layer;
A wiring board comprising: a conductor layer portion provided in the castellation portion so as to enter the groove portion and connected to the wiring conductor.   The wiring board according to claim 1, wherein the groove portion includes a plurality of the grooves, and the conductor layer portion includes a conductor layer provided in the plurality of grooves.   3. The wiring board according to claim 2, wherein an inner surface of the castellation portion has a corrugated shape by the plurality of grooves when seen in a plan view. The wiring board according to claim 1;
An electronic device comprising: an electronic component mounted on the wiring board.

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