JP2006269603A - Wiring board and multi-patterned wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring board on a side face of a board main body of which a groove for forming a conductor layer including a plating layer is provided, a mount strength is obtained with a mother board on which the wiring board is mounted, and the conduction with the mother board is stably attained; and to provide multi-patterned wiring board for surely attaining the tasks above. <P>SOLUTION: The wiring board 1 includes the board main body 2 made of a ceramic (insulating material) with a front side 3, a rear side 5, and side faces 4. Each corner between a pair of the side faces 4, 4 adjacent to each other in the board main body 2 is provided with the groove 10 located along the thickness direction of the board main body 2. Each groove 10 comprises a pair of end grooves 12 respectively adjacent to the front side 3 and the rear side 5 of the board main body 2, and a middle groove 11 located between them and interconnecting a pair of the end grooves 12. A pair of the end grooves 12 is greater than the middle groove 11, and a conductor layer 13 is formed to each groove 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wiring board having a groove for forming a conductor layer including a plating layer on a side surface of a board body, and a multi-cavity wiring board for reliably obtaining the wiring board.

When mounting the package on the surface of a motherboard, etc., a side metal layer is formed on the entire surface of the groove (castellation) provided along the thickness direction on the side surface of the board body in order to establish conduction with the external connection terminals on the surface. A leadless package and a manufacturing method for obtaining the leadless package have been proposed (see, for example, Patent Document 1).
The groove of the package has a substantially semicircular cross section having a constant width and depth along the thickness direction of the substrate body, and the side metal layer formed in the groove when the package is mounted on the surface of a mother board or the like. The contact area between the solder and the solder material tends to be small. For this reason, there is a possibility that the mounting strength at the time of mounting is insufficient, or conduction is unstable.

JP 2000-68414 A (pages 1-9, FIGS. 1-4)

Further, in Patent Document 1, in order to obtain a large number of the packages, a cylindrical through hole is formed along the boundary between adjacent package regions in a large size green sheet, and the inner surface of the through hole is formed. After forming a metal layer such as W, a plating layer is coated on the metal layer by electrolytic plating.
However, the through hole has the same inner diameter along the thickness direction of the large size green sheet, and the plating solution is difficult to flow into the through hole during the electrolytic plating. May cause variation. In particular, if the through hole is made small in size in order to meet the need for downsizing of the wiring board, the thickness of the plated layer is more likely to vary. For this reason, the continuity between the wiring board and the motherboard on which the wiring board is mounted may be unstable.

  The present invention solves the problems in the background art described above, has a groove for forming a conductor including a plating layer on the side surface of the substrate body, provides mounting strength with a mother board to be mounted, and is stable in conduction. It is an object of the present invention to provide a wiring board that can be removed in the process, and a wiring board for multiple pieces for obtaining the wiring board reliably.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the present invention provides a groove for forming a conductor layer including a plating layer on the side surface of the substrate body, both ends adjacent to the front surface and the back surface of the substrate body, and an intermediate portion connecting between them. The idea is to make the depth and width of the grooves different.
That is, the wiring board of the present invention (Claim 1) is made of an insulating material, and has a front surface, a back surface, and a substrate body having a side surface located along an outer periphery of the front surface and the back surface, and a side surface of the substrate body and an adjacent surface. A groove provided along the thickness direction of the substrate body in at least one of the corner portions between the pair of side surfaces, and the groove includes a pair of end grooves adjacent to the front surface and the back surface of the substrate body. And an intermediate groove connecting the pair of end grooves, the pair of end grooves being larger than the intermediate grooves.
The size of the end groove and the intermediate groove is based on both the depth and width of each groove.

According to this, the groove provided in the side surface or corner portion of the substrate body is constituted by a pair of end grooves adjacent to the front surface and the back surface of the substrate body, and an intermediate groove that connects between them and is smaller than these. Has been. For this reason, when mounting the wiring board on the surface of a mother board or the like, the groove is formed on the back surface of the board body, compared to a groove having a constant width and depth along the thickness direction of the board body as in the prior art. The contact area between the conductor layer formed on the surface of the adjacent end groove and the solder material (brazing material) can be increased. Further, as will be described later, since the plating layer in the conductor layer formed in the groove is coated almost uniformly with a required thickness, it is possible to stably establish conduction with the mother board. Therefore, the wiring board can be easily mounted with a required strength, and stable conduction can be achieved at the time of mounting.
The insulating material for forming the wiring board includes, for example, a ceramic mainly composed of alumina, a glass-ceramic which is a kind of low-temperature fired ceramic, or various resins including epoxy. The substrate body may be formed with a cavity that opens on the surface and mounts electronic components on the bottom surface.

In the present invention, the pair of end grooves adjacent to the front surface and the back surface of the substrate main body of the groove are formed of inclined surfaces that extend toward the front surface and the back surface of the substrate main body. (Claim 2) is also included.
According to this, since the pair of end grooves have inclined surfaces extending toward the front surface and the back surface of the substrate body, for example, have a substantially semi-conical shape or a substantially quarter conical shape, the wiring substrate Is mounted on the surface of a mother board or the like, the contact area between the conductor formed in the groove and the solder material can be increased. In addition, since the plating layer in the conductor layer formed in the groove is almost uniformly coated with a required thickness, conduction with the mother board can be stably taken. Therefore, it is possible to easily and reliably mount the wiring board with a required strength, and to ensure stable conduction.

In other words, the present invention may include a wiring board in which the pair of end grooves and the intermediate grooves constituting the grooves have different cross-sectional shapes.
In this case, for example, the end groove is substantially semi-conical and the intermediate groove is substantially semi-cylindrical, the end groove is almost semi-cylindrical and the intermediate groove is substantially rectangular in cross section, and the end groove is almost 1/4. It is possible to adopt a shape such as a cylindrical shape having an intermediate groove of approximately 1/4, or an end groove having a substantially cylindrical shape having a quarter, and an intermediate groove having a substantially rectangular cross section. .
Further, the present invention may include a wiring board in which a conductor layer made of a metal layer and a plating layer is formed on the surface of the end groove and the intermediate groove of the groove.
In this case, when the wiring board is mounted on the surface of a mother board or the like, it is possible to reliably establish conduction between the conductor layer and the connection terminal of the mother board.

  On the other hand, the multi-cavity wiring board of the present invention (Claim 3) includes a wiring board assembly region in which a plurality of wiring substrates are provided along the plane direction, and an ear portion surrounding the periphery of the wiring substrate assembly region, A through hole penetrating along the thickness direction of each wiring board at the boundary between the plurality of adjacent wiring boards in the wiring board assembly region and at the boundary between the wiring board and the ear portion, It is composed of a pair of end holes that are opened adjacent to the front and back surfaces of the wiring board, and an intermediate hole that is located between them and connects the pair of ends, and the diameter of the pair of end holes is The diameter is larger than the diameter of the intermediate hole. The size of the diameter of the end hole and the diameter of the intermediate hole is based on at least one of the inner diameter or the cross-sectional area of each hole.

According to this, the through hole is a pair of end holes opened adjacent to the front surface and the back surface of each wiring board, and is located between and connects the pair of end portions and a pair of end portions. An intermediate hole having a diameter smaller than the diameter of the hole is used. For this reason, when a metal layer such as W is formed in such a through hole, and a plating layer such as Ni plating, Au plating, and Ag plating is formed on the surface of the metal layer by electrolytic plating, Compared to the through hole, the plating solution can easily flow through the through hole with high fluidity. As a result, since the plating layer can be easily coated on the entire inner surface of the through hole with a relatively uniform thickness, when the wiring layer is separated into a plurality of wiring boards later, the conductor layer composed of the metal layer and the plating layer is interposed. Therefore, it is possible to reliably provide a wiring board that can be reliably connected to a mother board to be mounted.
The multi-piece wiring board includes, for example, a large-size laminate made of ceramic mainly composed of alumina, a large-size laminate made of glass-ceramic, which is one kind of low-temperature fired ceramic, or A large-size laminate composed of various resins including epoxy is included.

In the present invention, a pair of end holes adjacent to the front surface and the back surface of the wiring board among the through holes are formed by a substantially conical inclined surface extending toward the front surface or the back surface of the wiring board. A multi-piece wiring board (claim 4) is also included.
According to this, when a metal layer such as W is formed in the through hole, and a plating layer such as Ni, Au, and Ag is formed on the surface of the metal layer by electrolytic plating, the plating solution is used to form the through hole. Since it becomes easy to flow through with high fluidity, it is possible to easily cover the entire surface of the through-hole with a relatively uniform thickness.

In other words, the present invention may include a multi-cavity wiring board in which the pair of end holes constituting the through hole are cylindrical with a diameter larger than the inner diameter of the intermediate hole.
Also in this case, when the plating layer is electrolytically plated on the metal layer of the through hole, the plating solution can easily flow through the through hole with fluidity.
The present invention also includes a multi-cavity wiring board in which the inner surfaces of the pair of end holes and intermediate holes constituting the through hole are covered with a conductor layer made of a metal layer and a plating layer. Can be. In this case, it is possible to provide a wiring board capable of reliably connecting with a mother board to be mounted via the conductor layer when the multi-piece wiring board is divided into a plurality of wiring boards. It becomes.

In the following, the best mode for carrying out the present invention will be described.
FIG. 1 is a plan view showing a wiring board 1 according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line XX in FIG.
As shown in FIGS. 1 and 2, the wiring substrate 1 includes a substrate body 2 having a front surface 3, a back surface 5, and four side surfaces 4 positioned along the outer periphery thereof, and a corner between adjacent side surfaces 4 and 4. This section includes four grooves 10 provided along the thickness direction of the substrate body 2 and a conductor layer 13 formed on the surface of each groove 10.
The substrate body 2 is formed by integrally laminating alumina-based ceramic layers s1 to s5, for example, has a substantially square shape in plan view, and has a size of about 5 × 5 × 3 mm. A cavity 6 is opened on the surface 3 of the substrate body 2. The cavity 6 includes a bottom surface 7 having a substantially square shape in plan view and four side surfaces 8 erected from the periphery thereof, and penetrates through the central portions of the ceramic layers s4 and s5 near the surface 3 of the substrate body 2. .

As shown in FIGS. 1 and 2, a bottom surface 7 of the cavity 6 has a pair of pads (conductor layers) 9 and a solder (brazing material) 17 of a low melting point alloy such as Sn-Ag or Cu-Ag. Alternatively, the IC chip (electronic component) 16 is mounted via an epoxy adhesive resin (not shown). The pad 9 and the IC chip 16 are electrically connected via the bonding wire w. The pad 9 has a plating layer such as Ni and Au, which will be described later, formed on the surface of a metal layer made of W, Mo, Ag, or Cu.
As shown in FIG. 2, a wiring layer 18 having a predetermined pattern made of W, Mo, Ag, Cu or the like is formed between the ceramic layers s <b> 1 to s <b> 5 of the substrate body 2, and between these and the pad 9. A via conductor 19 made of the same metal as described above is formed therebetween. A pad (not shown) may be formed on the back surface 5 of the substrate body 2.

As shown in FIGS. 1 and 2, the corner portion between the adjacent side surfaces 4 and 4 of the substrate body 2 has a circular shape (arc shape) having a substantially quarter view and a surface 3 of the substrate body 2. And a pair of end grooves 12 adjacent to the back surface 5 and an intermediate groove 11 located between them and connecting between the pair of end grooves 12, 12 are formed. .
The pair of end grooves 12 constituting the groove 10 have a substantially conical shape of a quarter extending toward the front surface 3 and the back surface 5 of the substrate body 2, respectively, and the intermediate groove 11 has a cross section of 4 minutes. 1 circle (arc shape). The width and depth of the end groove 12 are larger than the width and depth of the intermediate groove 11.
The inclination angle (elevation angle) of the end groove 12 with respect to the virtual horizontal line in FIG. 2 is 45 to 85 degrees. If the inclination angle is less than 45 degrees, the corner portions of the front surface 3 and the back surface 5 of the substrate body 2 may be excessively shaved. On the other hand, when the inclination angle exceeds 85 degrees, the vertical contact angle becomes almost the same as 90 degrees, and the contact area with the solder material at the time of mounting cannot be made large. Can't improve sex. For these reasons, the inclination angle is in the range of 45 to 85 degrees.

On the surfaces of the intermediate groove 11 and the pair of end grooves 12 of the groove 10, a conductor layer 13 made of a metal layer made of W or the like and a plated layer made of Ni or Au is formed. As shown in FIG. 2, the conductor layer 13 is formed on the surface of the pair of end grooves 12 and a circular (arc-shaped) intermediate conductor 14 having a quarter cross section formed on the surface of the intermediate groove 11. Of the end conductor 15 having a substantially conical shape. Each intermediate conductor 14 is connected to one of the wiring layers 18 on the inner surface thereof.
The side surface of the cavity 6 is circular, oval, elliptical in a plan view, and has a substantially conical shape, a substantially conical shape, a substantially elliptical cone shape as a whole. You may form the light reflection layer which consists of plating layers, such as Au and Ag. In this case, when a light emitting element such as a light emitting diode or a semiconductor laser is mounted on the bottom surface 7 of the cavity 6, light from these can be efficiently reflected.

  According to the wiring board 1 as described above, the groove 10 provided in each corner portion of the substrate body 2 connects between the pair of end grooves 12 adjacent to the front surface 3 and the back surface 5 of the substrate body 2. And it is comprised with the intermediate groove 11 smaller in diameter than these. For this reason, when the wiring board 1 is mounted on the surface of a mother board (not shown) or the like, the back surface of the board body 2 is compared with a conventional groove having a certain width and depth along the thickness direction of the board body. 5, the contact area between the end conductor 15 of the conductor layer 13 formed in the end groove 12 adjacent to 5 and the solder material (not shown) can be increased. Moreover, as will be described later, since the plating layer in the conductor layer 13 formed in the groove 10 is almost uniformly coated with a required thickness, conduction with the motherboard side can be stably taken. Therefore, the wiring board 1 can be easily mounted with a required strength, and stable conductivity can be obtained at the time of mounting.

FIG. 3 is a plan view showing a multi-piece wiring board (hereinafter simply referred to as a wiring board) 20 for obtaining the wiring board 1.
As shown in FIG. 3, the wiring board 20 includes a wiring board gathering region 21 in which three wiring boards 1 are arranged in a vertical / horizontal (planar) direction for a total of nine, and the surroundings of the gathering region 21. And an ear portion 22 having a square frame shape. Note that the broken lines in FIG. 3 indicate the planned cutting lines when the wiring board 1 is individually divided later.
As shown in FIG. 3, in the thickness direction of each wiring board 1 at the intersection (boundary) of the four wiring boards 1 adjacent in the wiring board assembly region 21 and the boundary between the peripheral wiring board 1 and the ear part 22. A plurality of through holes 23 penetrating the aggregate region 21 and the collective region 21 and the ear portion 22 are formed. A plating electrode 29 having a substantially semicircular cross section is formed between the left and right ears 22.
Details of the through hole 23 and the metal layer and the plating layer formed on the surface thereof will be described in detail in the method of manufacturing the wiring board 20 described below.

A manufacturing method for obtaining the wiring board 20 will be described below.
First, as shown on the left side of FIG. 4, a large-size green sheet S1 made of an alumina-based material that becomes the ceramic layer s1 (s5) is fixed on a die D having a hole h having a circular cross section. A punch P having a diameter smaller than the inner diameter of the hole h and forming a required clearance c is prepared. As shown in the center of FIG. 4, by pushing the tip of the punch P into the hole h of the die D, a shearing action acts between the outer peripheral edge of the punch P and the inner peripheral edge of the hole h, and the cross section is substantially trapezoidal. Further, the substantially conical punching waste d is removed. As a result of the punching process, as shown on the right side of FIG. 4, a through hole h1 having a substantially conical inclined surface is formed at a predetermined position of the green sheet S1. The same number of the through holes h1 as the through holes 23 shown in FIG.

As shown in the upper part of FIG. 5, the same number of through-holes h1 are formed at the same position in the same manner as described above for the large-sized green sheet S5 made of an alumina-based material as the ceramic layer s5. . A cylindrical through hole is formed using a die D having a hole h with a minimum clearance c with respect to the diameter of the punch P, and then a conical mold (not shown) is formed in the through hole. The through-hole h1 having a substantially conical shape can also be formed by a method of pushing in.
Further, a die D having a hole h that has a minimum clearance c with respect to the diameter of the punch P is used for the large-size green sheets S2 to S4 made of an alumina-based material that becomes the ceramic layers s2 to s4. And punching each. Thereby, as shown in the middle of FIG. 5, a cylindrical through hole h2 is formed at a predetermined position. The same number of the through holes h2 as the through holes 23 shown in FIG.

In addition, the ceramic layers s4 and s5 are separately formed with the same number of through-holes having square cross-sections serving as the cavities 6 of the respective wiring boards 1 at the positions shown in FIG. In addition, as illustrated in FIG. 5, a paste-like metal layer (18) containing W powder or the like to be the wiring layer 18 is formed on the upper surfaces of the green sheets S1 to S4 by a known printing method. . The metal layer that becomes the pad 9 and the via conductor 19 is formed in the same manner.
Green sheets S2 to S4 having a cylindrical through hole h2 are arranged between green sheets S1 and S5 having a substantially conical through hole h1, so that the through hole h1 and the through hole h2 communicate with each other. Laminate and crimp. As a result, a large-size green sheet laminate GS whose partial cross section is shown in FIG. 6 is formed.

In the laminated body GS, a pair of upper and lower through holes h1 communicating with each other and three through holes h2 concentrically communicating therebetween are formed as shown in FIG. Form. The through-hole 23 is composed of a pair of upper and lower end holes 24 having a substantially conical inclined surface, and an intermediate hole 25 having a cylindrical inner peripheral surface located between them and connected with the same diameter. Is done.
As shown in FIG. 6, one end face of the paste-like metal layer (18) containing the W powder is exposed on the inner peripheral surface of the through hole 23. In addition, the electrode for plating (29) is formed in the same manner on the side surface of the side that is positioned outside the laminated body GS and becomes the ear portion 22 later.

Next, as shown on the left side of FIG. 7, one opening in each through hole 23 is communicated with a vacuum pump (not shown), and the inside of the through hole 23 is brought into a reduced pressure state. In this state, a mesh mask having a ring-shaped pattern hole located between an outer diameter slightly larger than the maximum diameter of the end hole 24 and an inner diameter slightly smaller than the other opening, and a squeegee (both not shown) The paste-like metal layer 27 containing W powder or the like is formed on the inner peripheral surface of the through hole 23 and the pair of end holes 25.
Subsequently, the other opening in each through hole 23 is communicated with a vacuum pump so as to be in a reduced pressure state similar to the above, and the pasty metal layer 27 is penetrated from one opening in each through hole 23 in the same manner as described above. It is formed almost uniformly on the inner peripheral surface of the hole 23.

In this state, the green sheet laminate GS is heated and held at a predetermined temperature range and fired, whereby the green sheets S1 to S5 become ceramic layers s1 to s5, and a paste-like metal layer (27) The plating electrode (29) and the like become the wiring layer 18 and the plating electrode 29.
Furthermore, as shown on the right side of FIG. 7, Ni plating and Au plating are performed on the metal layer 27 formed on the inner peripheral surface of the through hole 23 to form a plating layer 28. Such a plating process is formed by immersing the fired green sheet laminate GS in a plating solution (both not shown) in an electrolytic plating tank and performing known electrolytic Ni plating and electrolytic Au plating. .

That is, an electrode rod (not shown) is brought into contact with the plating electrode 29 of the fired green sheet laminate GS, and the tie bar (not shown) is positioned along the outer periphery of the laminate GS from the plating electrode 29. The metal layers 27 formed in all the through holes 23 are energized through the metal layers 27 formed in the through holes 23 and the wiring layers 18 of the respective wiring boards 1. In such a state, after the fired green sheet laminate GS and the electrode rod are immersed in a plating solution in an electrolytic plating tank, electrolytic Ni plating and electrolysis are performed between the opposite electrode in the plating solution. Au plating is performed sequentially. At this time, each plating solution has an end hole 24 having an inclined surface in which both ends of the through hole 23 spread outward, and thus flows through the through hole 23 with high fluidity.
As a result, the plating layer 28 is reliably formed with a relatively uniform thickness over the entire inner peripheral surface of the through hole 23 (24, 25).

Then, a known dicing process or break process is performed along a planned cutting line indicated by a broken line on the right side of FIG. 3 and FIG. As a result, the wiring board assembly region 21 is divided into nine wiring boards 1 and the ears 22 are removed. At this time, in each corner portion of the substrate body 2 in each wiring board 1, the intermediate hole 25 and the end hole 24 of the through hole 23 divided into four in plan view are the intermediate groove 11 and the end groove of the groove 10. 12 At the same time, the metal layer 27 and the plating layer 28 are divided into four parts, so that the intermediate conductor 14 and the end conductor 15 of the conductor layer 13 covering the surface of each groove 10 are formed.
According to the wiring board 20 manufactured as described above, the plating layer 28 having a substantially uniform thickness can be reliably formed on the inner peripheral surface of the through hole 23 via the metal layer 27, so that it can be mounted on a mother board or the like. It is possible to efficiently provide the wiring board 1 that can be easily connected.

FIG. 8 is a plan view showing a wiring board 30 of a different form according to the present invention, and FIG. 9 is a cross-sectional view taken along the line YY in FIG. In the following description, the same reference numerals are used for portions common to the wiring board 1.
As shown in FIGS. 8 and 9, the wiring substrate 30 includes a substrate body 32 having a front surface 33, a back surface 35, and four side surfaces 34 positioned along the outer periphery thereof, and the substrate body 32 between the side surfaces 34. Four grooves 40 provided along the thickness direction and a conductor layer 43 formed on the surface of each groove 40 are provided.
The substrate body 32 is also formed by integrally laminating the same ceramic layers s1 to s5 as described above, and the surface 33 of the substrate body 32 has a square bottom surface 37 in plan view and four side walls 38 standing from its periphery. A cavity 36 is opened. A pair of pads 9 is formed on the bottom surface 37 of the cavity 36 in the same manner as described above, the IC chip 16 is mounted in the center of the bottom surface 37 in the same manner as described above, and a bonding wire w is conducted between them. .

As shown in FIGS. 8 and 9, between each side surface 34 of the substrate main body 32, a pair of adjacent sides of the front surface 33 and the back surface 35 of the substrate main body 32 is substantially semicircular (semicircular arc shape) in plan view. A groove 40 is formed that includes an end groove 42 and an intermediate groove 41 that is located between the end groove 42 and connects between the pair of end grooves 42 and 42.
The pair of end grooves 42 constituting the groove 40 has a substantially semi-conical shape extending toward the front surface 33 and the back surface 35 of the substrate body 32, respectively, and the intermediate groove 41 has a substantially semicircular cross section (semicircle). Arc). The width and depth of the end groove 42 are larger than the width and depth of the intermediate groove 41. Note that the inclination angle (elevation angle) of the end groove 42 with respect to the virtual horizontal line in FIG. 9 is 45 to 85 degrees.

On the surface of the intermediate groove 41 and the pair of end grooves 42 of the groove 40, a conductor layer 43 made of a metal layer made of W or the like and a plating layer made of Ni or Au is formed. As shown in FIG. 9, the conductor layer 43 is formed on the surface of the pair of end grooves 42 and the intermediate conductor 44 having a substantially semicircular cross section (semicircular arc shape) formed on the surface of the intermediate groove 41. The end conductor 45 has a substantially semi-conical shape. Each intermediate conductor 44 is connected to one of the wiring layers 18 on the inner side surface.
In addition, the side surface of the cavity 36 is circular, oval, elliptical, generally in the form of a cone, substantially a long cone, or a substantially elliptical cone in plan view. You may form the light reflection layer which consists of plating layers, such as Au and Ag. In this case, when a light emitting element such as a light emitting diode or a semiconductor laser is mounted on the bottom surface 37 of the cavity 36, light from these can be efficiently reflected.

  According to the wiring board 30 as described above, the grooves 40 provided on the respective side surfaces 34 of the substrate body 32 connect the pair of end grooves 42 adjacent to the front surface 33 and the back surface 35 of the substrate body 32 and these. And it is comprised with the intermediate groove 41 smaller than these. For this reason, when mounting the wiring board 30 on the surface of a mother board (not shown) or the like, the back surface 35 of the board body 32 is compared with the groove having a constant width and depth along the thickness direction of the conventional board body. The contact area between the end conductor 45 of the conductor layer 43 formed in the adjacent end groove 42 and the same solder material (not shown) can be increased. In addition, as will be described later, since the plating layer in the conductor layer 43 formed in the groove 40 is almost uniformly coated with a required thickness, conduction with the motherboard side can be stably taken. Therefore, it is possible to easily mount the wiring board 30 with a required strength, and it is also possible to obtain a stable continuity during such mounting.

FIG. 10 is a plan view showing a multi-cavity wiring board (hereinafter simply referred to as a wiring board) 50 for obtaining the wiring board 30, and FIG. 11 is taken along the line ZZ in FIG. FIG.
As shown in FIG. 10, the wiring board 50 includes a wiring board gathering area 51 in which nine of the wiring boards 30 are arranged along the vertical and horizontal (planar) directions, and a surrounding area of the gathering area 51. The surrounding planar view includes a square frame-shaped ear portion 52. The broken lines in FIGS. 10 and 11 indicate the planned cutting lines when dividing into individual wiring boards 30 later.
As shown in FIG. 10, at the boundary between two wiring boards 30 adjacent to each other in the wiring board assembly area 51 and the boundary between the wiring board 30 and the ear 52 on the outer periphery, along the thickness direction of each wiring board 30, The collective region 51 and a plurality of through holes 53 penetrating the collective region 51 and the ear portion 52 are formed. A conductor layer 56 is formed on the inner peripheral surface of each through-hole 53. Further, on each side of the ear portion 52, a plating electrode 59 having a substantially semicircular cross section similar to the plating electrode 29 is formed.

As shown in FIG. 11, the through holes 53 are provided in the ceramic layers s <b> 1 and s <b> 5 and have a pair of end holes 54 having a substantially conical shape having inclined surfaces extending toward the front surface 33 and the back surface 35 of each wiring substrate 30. And an intermediate hole 55 which has a cylindrical shape with an inner diameter smaller than the inner diameter of the end hole 54, and the whole has a substantially drum shape.
On the surface of the intermediate hole 55 and the end hole 54 of the through hole 53, a metal layer 57 made of W or the like and a plating layer made of a Ni plating layer and an Au plating layer having a substantially uniform thickness are formed by the same method as described above. 58, a conductor layer 56 is formed.
Such a wiring board 50 is also easily manufactured through substantially the same manufacturing steps shown in FIGS.

Then, the wiring board assembly region 51 is divided into nine wiring boards 30 by performing a known dicing process or a break process along a planned cutting line indicated by a broken line in FIGS. And the ear | edge part 52 is removed. At this time, the intermediate hole 55 and the end hole 54 of the through hole 53 that are divided into two in plan view on the respective side surfaces 34 of the substrate body 32 in each wiring board 30 are the intermediate groove 41 and the end groove of the groove 40. 42. At the same time, the metal layer 57 and the plating layer 58 of the conductor layer 56 are each divided into two, thereby forming the intermediate conductor 44 and the end conductor 45 of the conductor layer 43 covering the surface of each groove 40.
Also with the wiring board 50 as described above, the plating layer 58 having a substantially uniform thickness is reliably formed on the inner peripheral surface of the through-hole 53 via the metal layer 57, so that mounting or conduction to a motherboard or the like is possible. It is possible to efficiently provide the wiring board 30 that can be easily taken.

The present invention is not limited to the embodiments described above.
The groove may be formed on both the side surface and the corner of the wiring board, and a conductor layer made of a metal layer and a plating layer may be formed in these grooves. Accordingly, through-holes are also formed in the multi-cavity wiring board at predetermined positions at the boundary between the wiring boards in the wiring board assembly area and at the boundary between the assembly area and the ear part.
The substrate body may be formed of glass-ceramic which is a kind of low-temperature fired ceramic. Or it is good also as a form which laminated | stacked the epoxy-type resin layer and the resin film on at least one of the surface of the core board | substrate which consists of BT resin. In the latter case, the metal layer formed in the pad, wiring layer, and groove is made of Cu or the like, and Ni and Au plating is performed on the surface thereof to form a conductor layer.

Further, the intermediate groove of the groove may have a rectangular cross section, and the end grooves at both ends may have a substantially half quadrangular pyramid shape. Or it is good also as an end groove | channel which is a semi-cylinder shape or a quarter cylinder shape with a large width | variety and depth with respect to the intermediate groove which is a semi-cylinder shape or a quarter cylinder shape.
Further, the through holes provided in the multi-wiring substrate corresponding to the shape of the groove may have a shape in which the intermediate hole has a substantially square cross section and the end holes at both ends have a substantially quadrangular pyramid shape. Or it is good also as an edge part hole which is a cylindrical column shape with a large width | variety and depth with respect to a cylindrical intermediate hole.
In addition, the wiring board may have a form in which the surface of the board body is flat and a pad for mounting an electronic component such as an IC chip on the surface.

The top view which shows the wiring board which is 1 form of this invention. Sectional drawing along the arrow of the XX in FIG. The top view which shows the wiring board for multi-piece taking for obtaining the said wiring board. Schematic which shows a part of manufacturing process of the said multi-cavity wiring board. Schematic which shows a part of manufacturing process following FIG. Schematic which shows a part of manufacturing process following FIG. Schematic which shows a part of manufacturing process following FIG. The top view which shows the wiring board of a different form. Sectional drawing along the arrow of the YY line in FIG. The top view which shows the wiring board for multi-piece taking for obtaining the said wiring board. FIG. 11 is a partially enlarged cross-sectional view taken along the line ZZ in FIG. 10.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,30 ... Wiring board 2,32 ... Board | substrate main body 3,33 ... Front surface 4,34 ... Side surface 5,35 ... Back surface 10,40 ... Groove 11, 41 ... Intermediate groove 12, 42 ... End groove 20, 50 ... Wiring boards for multi-cavity 21, 51 ... Wiring board assembly area 22, 52 ... Ear part 23.53 ... Through hole 24, 54 ... End hole 25, 55 ... Intermediate hole

Claims (4)

A substrate body made of an insulating material, having a front surface, a back surface, and a side surface located along the outer periphery of the front surface and the back surface;
A groove provided along the thickness direction of the substrate body in at least one of the side surface of the substrate body and a corner portion between a pair of adjacent side surfaces;
The groove is composed of a pair of end grooves adjacent to the front surface and the back surface of the substrate body, and an intermediate groove located between them and connecting the pair of end grooves,
The pair of end grooves are larger than the intermediate grooves,
A wiring board characterized by that. Among the grooves, the pair of end grooves adjacent to the front and back surfaces of the substrate body are configured by inclined surfaces that extend toward the front and back surfaces of the substrate body.
The wiring board according to claim 1. A wiring board assembly region in which a plurality of wiring boards are provided along the plane direction;
Ears surrounding the periphery of the wiring board assembly area;
A through hole penetrating along the thickness direction of each wiring board at the boundary between adjacent wiring boards in the wiring board assembly region and at the boundary between the wiring board and the ear part,
The through hole is composed of a pair of end holes that are opened adjacent to the front surface and the back surface of each wiring board, and an intermediate hole that is located between and connects the pair of end portions,
The diameter of the pair of end holes is larger than the diameter of the intermediate hole.
A wiring board for multi-piece production characterized by the above. Of the through-holes, a pair of end holes adjacent to the front and back surfaces of the wiring board are configured by a substantially conical inclined surface extending toward the front or back surface of the wiring board.
The multi-cavity wiring board according to claim 3, wherein:

Images