JP2016072606A - Wiring board and multi-piece wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board in which various electronic components such as a crystal vibrator can be mounted on a front side of a board body so as to be encapsulated, a surface of a conductor exposed outsides is surely coated with a metal plating film and at the time of mounting onto a mother board, trouble is unlikely to occur in rear-side electrodes, and a multi-piece wiring board which uses a plurality of wiring boards together.SOLUTION: A wiring board 1a includes: a board body 2a formed from a ceramic (insulation material) and including a front side 3 and a rear side 4 which are formed rectangular in a planar view; a plurality of rear-side electrodes 10 formed on the rear side 4 of the board body 2a; a frame-shaped conductor part 7 which is disposed on the front side 3 of the board body 2a and formed in a rectangular frame shape in a planar view; and a via-conductor 9 which penetrates the board body 2a and conducts the plurality of rear-side electrodes 10 and the frame-shaped conductor part 7. Between the plurality of rear-side electrodes 10 and sides 4a and 4b on the rear side 4 of the board body 2a, a part 4z of the rear side 4 is exposed. On the rear side 4 of the board body 2a, at least one or more protrusive wiring 12 are formed from the plurality of rear-side electrodes 10 to pairs of the sides 4a and 4b which cross each other.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a wiring board on which various electronic components such as a crystal resonator can be mounted on a surface in a sealable manner, and a multi-piece wiring board having a plurality of wiring boards.

For example, a substrate made of an insulating sheet, a pair of vibrating piece mount electrodes formed on the surface of the substrate, four external connection electrodes formed on each of the four corners on the back surface of the substrate, and the periphery of the surface There has been proposed a package for a piezoelectric vibrator including a rectangular frame-shaped metal ring fixed in place (see, for example, Patent Document 1). The lower ends of a pair of vias that are individually connected to the vibrating piece mount electrode and penetrate the substrate are individually connected to a pair of lead electrodes extending from the pair of external connection electrodes at the diagonal positions on the back surface to the center of the back surface. Connected to.
According to the above-described piezoelectric vibrator package, even if a thin substrate is used, cracks are hardly generated and reliability can be ensured in the manufacturing process of the piezoelectric vibrator using the package. A vibrator is obtained.

  However, in the case of the package for a piezoelectric vibrator described in Patent Document 1, in the first embodiment shown in FIGS. 1A to 1C, a plurality of the packages described above are shown in FIGS. When the current for covering the metal plating film is applied to the surface of each conductor that is continuously provided along the left and right directions), the current flows as follows: external connection electrode 17c → via 16 → metal ring 15 → via 16 → external connection electrode 17d → external connection electrode 17a of adjacent package → extraction electrode 18 → via 14a → first set stopped at the resonator element mounting electrode 12a and external connection electrode 17a → extraction electrode 18 → via 14a → The second set is stopped by the vibrating piece mount electrode 12a, and the third set is stopped by the external connection electrode 17b → the extraction electrode 18 → the via 14b → the vibrating piece mount electrode 12b. As a result, in the case of the package for the piezoelectric vibrator, a plurality of sets of plating current paths are required when the metal plating film is coated on the surface of each conductor exposed to the outside in each package. Further, in the multi-cavity configuration, it is impossible to cover the surface of each conductor exposed to the outside in each of the plurality of packages with a metal plating film. Therefore, it has been extremely difficult to provide a piezoelectric vibrator package in which the surface of each conductor exposed to the outside is reliably covered with a metal plating film.

JP 2008-5088 A (pages 1 to 11 and FIGS. 1 to 5)

  The present invention solves the problems described in the background art, and can mount various electronic components such as a crystal resonator on the surface of the substrate body in a sealable manner, and the metal plating film is surely provided on the surface of the conductor exposed to the outside. It is an object of the present invention to provide a wiring board that is covered with a wiring board and that is unlikely to have a problem with a back electrode when mounted on a mother board, and a multi-cavity wiring board that includes a plurality of wiring boards.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the present invention provides a multi-cavity wiring board having a plurality of wiring boards, and a metal plating film is reliably coated on the surface of a conductor exposed to the outside in each wiring board, In addition, it is conceived that a plurality of back surface electrodes formed on the back surface of the substrate body of the wiring board after being separated into pieces are formed away from the respective sides of the back surface.
That is, the wiring board of the present invention (Claim 1) is made of an insulating material, and has a substrate body having a front surface and a back surface that are rectangular in plan view, a plurality of back electrodes formed on the back surface of the substrate body, and A frame-shaped conductor portion that is disposed on the front surface side of the substrate body and has a rectangular frame shape in plan view; and a via conductor that passes through the substrate body and conducts between the plurality of back surface electrodes and the frame-shaped conductor portion. A part of the back surface is exposed between the plurality of back surface electrodes and each side of the back surface of the substrate body, and the plurality of back surface electrodes on the back surface of the substrate body. At least one or more convex wirings are formed between the back electrode and a pair of sides intersecting each other.

According to this, since the plurality of back surface electrodes formed on the back surface of the substrate body are formed away from the respective sides of the back surface, the solder used when mounting this wiring board on a mother board such as a printed circuit board. The stress accompanying the tensile force generated during solidification can be relaxed. Therefore, it is possible to make it difficult to cause problems such as peeling of the outer peripheral side of the back electrode.
In addition, at least one or more convex wirings are formed between the back electrode and a pair of sides that intersect (orthogonal) each other on the back surface of the substrate body. Therefore, in the state of a multi-cavity wiring board, which will be described later, in which a plurality of wiring boards are arranged side by side in the vertical and horizontal directions, the connection wiring made of mutual convex wiring between adjacent wiring boards is provided on the back surface of each board body. At least one or more are provided on the side. Therefore, when a plating current is applied to a plurality of wiring boards, the plating current can be passed along the vertical direction, the horizontal direction, and the diagonal direction of the plurality of wiring boards. Accordingly, there is provided a wiring board in which a required metal plating film is reliably coated on the surface of the plurality of back surface electrodes, the frame-shaped conductor portion, and the conductor portion exposed to the outside such as a mounting electrode formed on the surface of the substrate body. can do.

The insulating material forming the substrate body is ceramic or resin. Examples of the ceramic include high-temperature fired ceramics such as alumina, aluminum nitride, and mullite, and low-temperature fired ceramics such as glass-ceramic, and the resin includes, for example, an epoxy resin.
The substrate main body is composed of a single ceramic layer or a single resin layer. However, the substrate body is composed of a laminate of a plurality of ceramic layers or a plurality of resin layers, and for connecting the via conductor on the upper layer side and the via conductor on the lower layer side between these layers, for example. The wiring layer for routing may be formed. For example, in the case of a substrate main body in which a flat ceramic layer and a ceramic layer having a rectangular frame shape in plan view are stacked, the surface of the substrate main body has a rectangular outer shape in plan view and a rectangular frame shape. It will be a thing.
Furthermore, the rectangular frame-shaped frame-shaped conductor portion arranged on the surface side of the substrate body is along the periphery on the surface of the metal frame or the upper insulating layer (for example, ceramic layer) constituting the substrate body. And a frame-shaped metallization layer formed on the surface (surface) of a rectangular frame-shaped frame body made of an insulating material (for example, a ceramic layer).
In addition, a plurality of mounting electrodes for mounting a crystal resonator, a semiconductor element, and the like are formed on the surface of the substrate body surrounded by the metal frame forming the frame-shaped conductor portion or the frame body, The plurality of mounting electrodes and the plurality of back conductors are individually connected by via conductors.

Further, the back electrodes are formed, for example, in the form of a pair (two pieces) arranged along the vicinity of a pair of opposing sides on the back surface of the substrate body, or in the vicinity of a side between two adjacent corners. A configuration including a total of three back surface electrodes including one and two separately formed for the remaining two corner sides is also included.
Further, on the back surface of the substrate body, when the plurality of convex wirings attached to the back surface electrode extend toward a pair of adjacent sides that cross each other, at least two adjacent to each other with a corner interposed therebetween The bases of the convex wirings are directly connected to the back electrode without crossing each other.
Further, the convex wiring has a form extending in a straight line and a direction perpendicular to the side closest to the back surface of the substrate body, a form extending in a slant and straight line, and a bottom view. And a shape in which the L shape is extended and the tip is perpendicular to the side.
In addition, the thickness of the back electrode and the convex wiring is in the range of about 10 to 50 μm, and the width of the convex wiring is in the range of about 10 to 300 μm.

In the present invention, the plurality of back electrodes are formed at four corners on the back surface of the substrate body on each corner side, and each back electrode is between the pair of sides intersecting each other on the back surface. In addition, a wiring board (claim 2) in which at least one convex wiring is formed is also included.
According to this, at least one or more convex wirings are formed between the four back electrodes formed on the back surface of the substrate body and a pair of sides intersecting (orthogonal) with each other on the back surface. Has been. Therefore, in the state of a multi-piece wiring board to be described later, at least two or more connection wirings composed of convex wirings between adjacent wiring boards are arranged on each side of the back surface of each board body. The As a result, when the plating current is supplied to each of the plurality of wiring boards, the plating current is stably flowed along the vertical direction, the horizontal direction, and the diagonal direction of the plurality of wiring boards, so that they are exposed to the outside. It is possible to provide a wiring board in which the surface of the back electrode or the like is more reliably coated with a metal plating film.
Furthermore, when the plating current is applied to each of the plurality of wiring boards, the plating current is applied along a plurality of directions (vertical direction, horizontal direction, and diagonal direction in plan view) between the plurality of wiring boards. Therefore, the thickness of the metal plating film coated on the surface of the back electrode exposed to the outside can be made uniform. In addition, since the plating current flows along a plurality of directions (energization paths), for example, even when one of the plurality of conduction paths is disconnected, the back electrode exposed to the outside, etc. The metal plating film can be reliably coated on the surface.
In the present invention, a plurality of mounting electrodes are formed on the surface of the substrate body surrounded by the frame-shaped conductor portion in plan view, and the plurality of mounting electrodes and the plurality of back electrodes are provided between the mounting electrodes and the back electrodes. In addition, a wiring board that is individually connected by a via conductor that penetrates the board body may be included.
In this case, in the state of a multi-cavity wiring board to be described later, a plating current flows to each of the plurality of mounting electrodes via any one of the back electrode and the via conductor. Also, the metal plating film is securely coated.

  On the other hand, a multi-piece wiring board according to the present invention (Claim 3) includes a product region in which a plurality of the wiring boards are arranged adjacent to each other along a vertical and horizontal direction in a plan view, and an insulating material similar to the board body. An ear portion having a front surface and a back surface, surrounding the periphery of the product region and having a rectangular frame shape in plan view, a plurality of plating electrodes formed around the ear portion, and the plating A multi-layer wiring board comprising: an electrode and a plated wiring that conducts between the convex wiring for each of the wiring boards located on the peripheral side of the product region, wherein a boundary is sandwiched in the product region A pair of wiring boards adjacent to each other is formed of a pair of convex wirings and is electrically connected via a connection wiring straddling the boundary.

According to this, when an electrode bar or the like is brought into contact with the electrode for plating on one side facing the ear portion and energized, the plating current is passed through the plating wiring and the connection wiring in the product region. After flowing through the back electrode for each wiring board, the connection wiring, and the plating wiring on the opposite side, it flows to the plating electrode on the other side facing the ear portion. Alternatively, the plating current is supplied from the back electrode for each wiring board in the product area via the plated wiring and connection wiring to another back electrode, connection wiring, and adjacent wiring via the via conductor and frame conductor. After flowing through the back surface electrode of the substrate and the opposite side plating wiring, it flows to the plating electrode on the other side facing the ear portion. At this time, the plating current is reliably transferred between the back electrodes of each of the plurality of wiring boards adjacent vertically and horizontally in the product region along the longitudinal direction, the lateral direction, and the oblique direction through the connection wiring. Washed away. Therefore, in each wiring board, a multi-cavity wiring board in which a required metal plating film such as Ni and Au is securely coated on the surface of the back electrode and the frame-shaped conductor portion exposed to the outside. ing.
The electrode for plating formed on each side of the ear portion of the multi-piece wiring board is a semi-cylindrical conductor portion formed along the inner wall surface of the concave groove recessed in a semicircular shape in plan view. .
In addition, the plated wiring formed on the ears of the multi-piece wiring board includes a plurality of wiring boards located on the peripheral side of the product area close to the side of the ears where the plating electrodes and the plating electrodes are located. In order to connect the tips of the plurality of convex wirings extending from the back electrode to the ear portion side, a form extending radially from the plating electrode for each tip of the plurality of wires, or the ear portion A main line portion extending along the side of the back surface of the wire, a root line portion extending from the main line portion to the plating electrode, and a plurality of branch line portions extending from the main line portion for each tip portion of the plurality of convex wirings It is included.

Further, the present invention provides a multi-piece wiring board in which division grooves having a lattice shape in plan view are formed on the surface side of the product region along the boundary defining a plurality of wiring boards. 4) is also included.
According to this, for example, when the substrate body is made of ceramic, a plurality of the wiring substrates can be obtained easily and accurately by applying a shearing force along the dividing grooves.
The boundary is an imaginary line (vertical surface) that partitions adjacent wiring boards in plan view, and the whole has a lattice frame shape in plan view.
Moreover, the said division | segmentation groove | channel contains the form in which a cross section exhibits a U shape by laser processing, and the form in which a cross section exhibits a V shape by insertion of a cutter.
Furthermore, the connection wiring that has connected the back surface electrodes of two wiring boards adjacent to each other with the boundary interposed therebetween becomes the convex wiring when separated along the dividing groove.
In addition, the dividing groove may be formed by inserting a blade with a required depth from the surface side of the boundary, even if the substrate body and the ear portion of each wiring substrate are made of resin.

The top view which shows the wiring board of one form by this invention. FIG. 2 is a vertical sectional view taken along line XX in FIG. 1. The bottom view of the said wiring board. The vertical sectional view similar to FIG. 2 which shows the wiring board of a different form. Furthermore, the same vertical sectional view as FIG. 2 which shows the wiring board of a different form. The bottom view of the above wiring board which has a back surface electrode of an application form. The top view which shows the multi-piece wiring board of one form by this invention. The bottom view which shows the said multi-piece wiring board. The vertical sectional view which shows the outline of the electricity supply structure of the said multi-piece wiring board. The partial bottom view which shows the relationship between the said back surface electrode and convex wiring. The bottom view of the said wiring board which has a back surface electrode of a different form. Furthermore, the bottom view of the said wiring board containing the back surface electrode of a different form. The bottom view of the said wiring board which has a back surface electrode of an application form. The partial bottom view of the multi-piece wiring board which has multiple said wiring boards.

Hereinafter, modes for carrying out the present invention will be described.
1 is a plan view showing a wiring board 1a according to an embodiment of the present invention, FIG. 2 is a vertical sectional view taken along the line XX in FIG. 1, and FIG. 3 is a bottom view of the wiring board 1a. FIG.
As shown in FIGS. 1 to 3, the wiring substrate 1 a is made of ceramic (insulating material), and includes a substrate body 2 a composed of a front surface 3 and a rear surface 4 that are rectangular (rectangular) in plan view, and side surfaces 5 of four sides. The four back surface electrodes 10 formed on each corner side of the back surface 4 of the substrate body 2a and the periphery of the surface 3 of the substrate body 2 are arranged in a rectangular frame shape in plan view. In order to conduct between the ring (frame-shaped conductor portion) 7 and the metal ring 7 and the four back electrodes 10, a plurality of individually penetrating between the front surface 3 and the back surface 4 of the substrate body 2 are provided. And via conductors 9.

The single ceramic layer constituting the substrate body 2a is made of, for example, a high-temperature fired ceramic such as alumina, or a low-temperature fired ceramic such as glass-ceramic. An arc wall 5a for preventing chipping (so-called chipping) and preventing cracks is disposed between the four side surfaces 5 of the substrate body 2a.
The four back electrodes 10 have a rectangular shape when viewed from the bottom. A portion 4z of the back surface 4 is exposed in a strip shape between the four back electrodes 10 and the long side (side) 4a and the short side (side) 4b of the back surface 4 of the substrate body 2a. ing. One convex wiring 12 is at right angles between the outer side of each back electrode 10 and a pair of long sides 4a and short sides 4b that cross each other at right angles in a bottom view and are adjacent to each other. It is formed so as to extend linearly. The convex wiring 12 is rectangular (rectangular) when viewed from the bottom, but is not limited to this shape.
In FIG. 3, the back electrode 10 located on the upper left side of the back surface 4 of the substrate body 2 is formed with a hypotenuse 11 for identifying the position and posture of the substrate body 2a itself and the like. Further, the thickness of the back electrode 10 and the convex wiring 12 is in the range of about 10 to 50 μm, and the width of the convex wiring 12 is in the range of about 10 to 300 μm.

The metal ring 7 is made of, for example, Kovar (Fe-29% Ni-17% Co), 42 alloy (Fe-42% Ni), or 194 alloy (Cu-2.3% -0.03% P). Etc. The metal ring 7 has a substantially square vertical cross section at each portion, and a brazing material such as Ag brazing (see FIG. 5) disposed between the entire bottom surface of the metal ring 7 and the peripheral portion of the surface 3 of the substrate body 2a. It is fixed to the periphery of the surface 3 via a not-shown). A cavity 6 having a rectangular shape in plan view is formed surrounded by the inner surface of the metal ring 7 and the surface 3 of the substrate body 2a. A pair of mounting electrodes 8 a and 8 b are formed on the surface 3 of the substrate body 2 a that is surrounded by the metal ring 7 and is also the bottom surface of the cavity 6 in plan view. One end of a crystal resonator 13 or the like is joined to the upper surfaces of the mounting electrodes 8a and 8b, and via conductors 9 are respectively provided between the pair of back electrodes 10 located on the left side in FIG. Connected individually.
In order to seal the opening of the cavity 6 on which the crystal unit 13 or the like is mounted, a metal lid (not shown) having a rectangular shape in plan view is formed on the upper surface of the metal ring 7 by resistance welding or soldering. Joined by attaching. Further, in place of the crystal resonator 13, a semiconductor element (not shown) or the like may be mounted in the cavity 6. In this case, the number of mounting electrodes 8n is three or more (for example, four), It may be possible to conduct individually through the back electrode 10 and the via conductor 9 located almost immediately below each other.

In addition, the four back electrodes 10 in which the pair of mounting electrodes 8a and 8b, the plurality of via conductors 9, and the pair of convex wirings 12 are extended are composed of a high-temperature fired ceramic such that the substrate body 2a is alumina or the like. Is formed by printing W, Mo, Cu or the like, and when the substrate body 2a is made of a low-temperature fired ceramic such as glass-ceramic, Ag or Cu is formed by printing.
Further, the convex wiring 12 is not limited to a form that intersects between the back electrode 10 and the respective sides 4a and 4b of the substrate body 2a (part 4z of the back surface 4) with a straight line of the shortest distance and at a right angle. Further, it may be configured to extend along an oblique direction, or to have an arbitrary shape such as a trapezoid in a bottom view.

FIG. 4 is a vertical sectional view similar to FIG. 2, showing a wiring board 1b having a different form from the wiring board 1a.
As shown in FIG. 4, the wiring board 1b has a board body 2b instead of the board body 2a, and has a plan view formed on the surface 3 of the board body 2b instead of the metal ring 7. A frame-shaped metallized layer (frame-shaped conductor portion) 14 having a rectangular frame shape is provided. The substrate body 2b is formed by integrally laminating a flat ceramic layer c1 and a ceramic layer c2 having a rectangular frame shape in plan view and a substantially square cross section along the periphery of the surface 3b. The surface 3 has a rectangular outer shape in plan view and a rectangular frame shape. The frame-shaped metallized layer 14 is also made of a conductor layer formed by printing W, Mo, Cu or the like similar to the above.

The back surface 4 of the substrate body 2b has the same four back surface electrodes 10 and the same convex wirings extending individually from the outer sides to the long side 4a and the short side 4b of the back surface 4 respectively. 12 are formed. Further, the same cavity 6 is located on the surface 3b of the lower ceramic layer c1 surrounded by the upper ceramic layer c2, and the same surface 3b as the bottom surface of the cavity 6 is the same as the above. Mounting electrodes 8a and 8b are formed.
As shown in FIG. 4, via conductors 9 penetrating the ceramic layers c1 and c2 are individually disposed between the frame-shaped metallized layer 14 and the four back conductors 10, and mounting electrodes 8a, Via conductors 9 penetrating the lower ceramic layer c1 are individually disposed between 8b and the two back conductors 10 located on the left side in FIG.

FIG. 5 is a vertical sectional view similar to FIG. 2 showing a wiring board 1c having a different form from the wiring boards 1a and 1b.
As shown in FIG. 5, the wiring board 1c has a substrate body 2c in which a lower ceramic layer c1 and a flat ceramic layer c2 on the lower layer are integrally laminated instead of the substrate body 2a. ing. Further, a metal ring 7 having a rectangular frame shape in plan view is fixed in the same manner as described above along the periphery of the surface 3 of the substrate body 2c. For example, as shown in FIG. 5, the ceramic layers c1 and c2 are suspended from mounting electrodes 8a and 8b formed on the surface 3 surrounded by the metal ring 7 and also the bottom surface of the cavity 6. In addition, a connection wiring 15 for connecting a plurality of via conductors 9 penetrating the ceramic layer c2 is formed. Further, as shown in FIG. 5, the via conductor 9 other than the above penetrates between the ceramic layers c1 and c2, or penetrates only the lower ceramic layer c1. A power supply layer, a ground layer (not shown), or the like may be formed between the ceramic layers c1 and c2.

FIG. 6 is a bottom view of the wiring board 1a having the back electrode 10 of an application form.
As shown in FIG. 6, on the back surface 4 of the substrate body 2a of the wiring substrate 1a, four back electrodes 10 are formed in the same manner as described above on each corner side of the back surface 4, and each back electrode 10 and the back surface 4 are formed. One convex wiring 12 is formed between each short side 4b as in the previous period. Further, two convex wirings 12 are formed between each back electrode 10 and each long side 4 a of the back surface 4.
As described above, in the form shown in FIG. 6, on the back surface 4 of the substrate body 2 a, the four back electrodes 10 formed on each corner side of the back surface 4 intersect each other at right angles on the back surface 4. A total of twelve convex wirings 12 are formed between each pair of adjacent sides 4a and 4b.
In addition, it is also possible to apply the back electrode 10 having the convex electrode 12 having the above-described configuration to the wiring boards 1b and 1c by replacing the substrate body 2a with the substrate bodies 2b and 2c.

According to the wiring boards 1a to 1c as described above, the plurality of back surface electrodes 10 formed on the back surface 4 of the substrate bodies 2a to 2c are separated from the long side 4a and the short side 4b of the back surface 4 respectively. The convex electrode 12 is formed across a portion 4z of the back surface 4. By the way, when the outer peripheral sides of the plurality of back electrodes 10 formed on the back surfaces 4 of the substrate bodies 2a to 2c are in contact with the respective long sides 4a and short sides 4b of the back surface 4, the outer periphery side of the back electrodes 10 is the side surface 5. Exposed to. When the wiring board of this form is mounted on a mother board such as a printed circuit board, the back electrode 10 and the substrate exposed to the side surface 5 receive the tensile force when the solder used for the mounting cools and hardens. The back electrode 10 may be peeled off starting from the boundary between the main bodies 2a to 2c. In particular, when the side surface 5 of the substrate bodies 2a to 2c has a grooved surface on the front surface 3 side and a fracture surface on the back surface 4 side, the back electrode 10 is easily peeled off when exposed near the fracture surface.
On the other hand, according to the wiring boards 1a to 1c, since the outer peripheral side of the back electrode 10 is not exposed to the side surface 5, when the solder used for mounting cools and hardens, the back electrode 10 receives a tensile force. However, problems such as peeling of the outer peripheral side of the back electrode 10 are less likely to occur.

In addition, when the convex wiring 12 is largely exposed on the side surface 5, the back electrode 10 is easily peeled off in the same manner as the outer side of the back electrode 10 is in contact with the long side 4 a and the short side 4 b of the back surface 4. The case that becomes. Therefore, the width and thickness of the convex wiring 12 and the area exposed on the side surface need to be selected and designed as appropriate.
In addition, one or two convex wirings 12 are provided between the back electrode 10 and a pair of long sides 4a and short sides 4b that intersect (orthogonal) each other on the back surfaces 4 of the substrate bodies 2a to 2c. Therefore, in the state of a multi-piece wiring board 20 described later in which a plurality of wiring boards 1a to 1c are provided side by side in the vertical and horizontal directions, the wiring boards 1a to 1c are adjacent to each other. At least one connection wiring 32 composed of the convex wiring 12 is disposed on each of the long side 4a and the short side 4b on the back surface 4 of each of the substrate bodies 2a to 2c. Therefore, when a plating current is applied, the plating current flows along the vertical direction, the horizontal direction, and the diagonal direction of the plurality of wiring boards 1a to 1c. Therefore, the surfaces of the conductor parts exposed to the outside such as the plurality of back electrodes 10, the metal ring 7 or the frame-shaped metallized layer 14, and the mounting electrodes 8a and 8b formed on the surfaces 3 and 3b of the substrate bodies 2a to 2c. The wiring boards 1a to 1c are securely coated with a required metal plating film.

7 is a plan view of a multi-piece wiring board 20 having a plurality of the wiring boards 1a along the length and breadth, FIG. 8 is a bottom view of the multi-piece wiring board 20, and FIG. 3 is a vertical cross-sectional view illustrating an outline of a current-carrying structure of a wiring board 20.
As shown in FIGS. 7 and 8, the multi-piece wiring board 20 includes a product region 21 having a rectangular shape in plan view in which a plurality of the wiring boards 1a are arranged adjacent to each other along the vertical and horizontal directions, and It is made of the same ceramic (insulating material) as described above, has a front surface 3 and a back surface 4, surrounds the periphery of the product region 21, and includes an ear portion 22 having a rectangular frame shape in plan view. Between the plurality of wiring boards 1a located in the product region 21 and between the product region 21 and the ear portion 22, virtual boundaries 23 that partition between these are preset in a lattice shape in plan view. Has been. A through hole 25 having a circular shape in plan view is formed at each position where the boundaries 23 intersect at right angles. The through-hole 25 forms the arc wall 5a when it is divided for each wiring board 1a later.
Two grooves 27 each having a semicircular shape in plan view are formed around each of the long sides around the pair of opposing long sides of the ear portion 22, and are planar along the inner wall surface of each groove 27. A plating electrode 26 having a semi-circular shape and a semi-cylindrical shape as a whole is formed.

Further, as shown in FIG. 8, between the pair of plating electrodes 26 positioned for each long side of the ear portion 22 and the back electrode 10 for each of the wiring boards 1 a positioned on the peripheral side of the product region 21. Are respectively formed with plated wirings 28 for conducting between them. The plated wiring 28 includes a main line portion 30 that is elongated along the longitudinal direction of each long side of the ear portion 22, a root line portion 29 that extends from the main line portion 30 to each plating electrode 26, and the main line portion 30. It is comprised from the branch line part 31 extended between the back surface electrodes 10 for every wiring board 1a.
Further, as shown in FIG. 8, in the product region 21, the back surface electrodes 10 and 10 of the pair of wiring boards 1 a adjacent to each other along the vertical and horizontal directions straddle the boundary 23 (intersect). ) A connection wiring 32 that electrically connects each other is wired.

In addition, as shown in FIG. 9, on the surface 3 side of the boundary 23, division grooves 24 having a required depth from the surface 3 are formed in a lattice shape in plan view. In order to manufacture the multi-cavity wiring board 20, the dividing groove 24 is a grid pattern of cutting tools from the surface side of a single-layer green sheet having both the wiring boards 1 a and the ears 22 in the product region 21. It is formed by inserting into a shape, and its vertical cross section is V-shaped.
The plated wiring 28 is also made of W, Mo, or Cu as described above.
Further, the branch line portion 31 includes a portion to be the convex wiring 12 in the product area 21 when the plurality of wiring boards 1a are individually divided later, and the connection wiring 32 is the same as described above. When divided, it is divided into convex wirings 12 for each wiring board 1a.

Furthermore, the metal ring 7 used for the wiring board 1a is fixed to the periphery of the surface 3 via a brazing material (not shown) such as Ag brazing. On the other hand, with the downsizing of the wiring board 1a, the pitch between adjacent metal rings 7 in the multi-piece wiring board 20 is narrowed. As a result, if a sufficient amount of brazing material is used for fixing, the brazing material of the adjacent wiring board 1a may flow out. Therefore, in the multi-piece wiring board 20 in which a plurality of wiring boards 1 a are arranged vertically and horizontally, the dividing groove 24 is formed along the surface 3 side of the boundary 23, and the brazing material enters the dividing groove 24. Thus, it is possible to prevent the brazing material from flowing into the adjacent wiring board 1a. In addition, since the said division | segmentation groove | channel 24 was formed in the surface 3 side, the connection wiring 32 which connects mutually mutually across the back surface 4 side of the boundary 23 is formed in this back surface 4 side. .
Moreover, the said through-hole 25 becomes the said circular arc wall 5a located in each corner of the board | substrate body 2a for every wiring board 1a, when dividing similarly to the above.
In addition, the vertical cross section of the dividing groove 24 may be U-shaped by irradiating the surface of the green sheet while scanning the laser in a lattice shape in plan view.

According to the multi-cavity wiring board 20 as described above, as shown in FIG. 9, when an electrode bar or the like is brought into contact with the plating electrode 26 on one long side of the ear portion 22 and energized, the plating current is Through the plated wiring 28 (29 to 31), the peripheral back electrode 10, the via conductor 9, the metal ring 7, the via conductor 9, and the product region for each peripheral wiring board 1a in the product region 21 21 and flows through the back electrode 10 at the center side thereof, and further via the connection wiring 32, the back electrode 10, the via conductor 9, the metal ring 7, the via conductor 9, and the opposite side of the adjacent wiring board 1 a. After flowing through the back surface electrode 10, it flows through the plating wire 28 on the other long side and then flows to the plating electrode 26 on the other long side at the ear portion 22. At this time, the plating current passes along the vertical, horizontal, and diagonal directions between the back electrodes 10 of each of the plurality of wiring boards 1a adjacent to each other in the vertical and horizontal directions in the product region 21 via the connection wiring 32. Surely flowed.
Accordingly, when the wiring substrate 1a is divided along the dividing grooves 24, the surface of the back surface electrode 10, the metal ring 7, and the mounting electrodes 8a and 8b exposed to the outside, for example, Ni, Au, etc. Thus, a multi-piece wiring board 20 can be provided which can provide a plurality of wiring boards 1a coated with the required metal plating film.

  The multi-piece wiring board 20 may have a configuration in which a plurality of the wiring boards 1b or a plurality of the wiring boards 1c are arranged in the product region 21 vertically and horizontally. Among these, also in the case of the wiring board 1c, the dividing groove 24 is formed on the surface 3 side of the boundary 23. However, the dividing groove 24 is formed by the thickness of the ceramic layers c1 and c2 as compared with the configuration in which the wiring board 1a is disposed. It is necessary to form deeply. In this embodiment, in the multi-piece wiring board 20, the dividing grooves 24 are formed deeply in order to form the connection wiring 32 that electrically connects each other across the boundary 23 (crossing) on the back surface 4 side. Is easy.

FIG. 10 is a partial bottom view showing the relationship between the back electrode 10 and the convex wiring 12.
The back electrode 10 formed on each corner side of the back surface 4 of the substrate bodies 2a to 2c of the wiring boards 1a to 1c has a substantially rectangular shape when viewed from the bottom, and the back surface 4 from the middle of every two sides on the outside. In FIG. 1, at least one (a pair) of convex wirings 12 is formed toward the long side 4a and the short side 4b that intersect each other.
As shown in FIG. 10, in the back surface electrode 10 formed for each corner side of the back surface 4, a pair of convex wirings 12 sandwiching the corner and intersecting (orthogonal to each other) are adjacent to at least their bases. May be formed so as not to cross each other and to be directly connected to the outer side of the back electrode 10. Note that the back electrode 10 including the pair of convex wirings 12 in such a form is applied to all of the wiring boards 1 a to 1 c and can also be included in the multi-piece wiring board 20.

FIG. 11 is a bottom view of the wiring board 1a having the back electrode 10a of a different form.
As shown in FIG. 11, on the back surface 4 of the substrate body 2a of the wiring board 1a, a strip-shaped back surface from the long side 4a and a pair of adjacent short sides 4b along the pair of long sides 4a on the back surface 4, respectively. A pair of back surface electrodes 10a having a long and narrow rectangular (trapezoidal) shape in a bottom view are formed apart from the portion 4z. The back electrode 10a includes a total of four convex wirings 12, two on each corner side of the long side 4a of the back surface 4, and one convex wiring for each corner side of the pair of left and right short sides 4b facing each other. 12 are extended toward the long side 4a and the short side 4b. In FIG. 11, a concave portion 11a for confirming the position and posture is formed on the inner side of the upper back electrode 10a.
The back electrode 10 a including the plurality of convex wirings 12 may be applied to the wiring boards 1 b and 1 c and may be included in the multi-piece wiring board 20.
Further, the pair of back surface electrodes 10a may be formed in the same manner as described above while being close to each other for each pair of short sides 4b on the back surface 4.

FIG. 12 is a bottom view of the wiring board 1a including the back electrode 10b of a different form.
As shown in FIG. 12, on the back surface 4 of the substrate body 2a of the wiring board 1a, the same pair of back surface electrodes 10 are formed on each corner side on the left side of the back surface 4, and on the right side of the back surface 4. Is a rectangular or trapezoidal shape when viewed from the bottom, with the strip-like back surface portion 4z being separated from the short side 4b and a pair of adjacent long sides 4a along the right short side 4b in the drawing. A back electrode 10b is formed. That is, a total of three of a pair of back surface electrodes 10 and a single back surface electrode 10b are formed on the back surface 4. The back electrode 10b includes four convex wirings 12 on each side, one for each corner side of the short side 4b on the right side and one for each corner side of the pair of long sides 4a adjacent to the short side 4b. It extends toward 4a and 4b.
Note that the above-described configuration of a total of three pairs of the back electrode 10 and the single back electrode 10b may be applied to the wiring boards 1b and 1c, and the multi-piece wiring board 20 is used. Can also be included.
Further, on the back surface 4, one back electrode 10a is formed along the vicinity of one long side 4a, and two back electrodes 10 are formed on each corner side of the other long side 4a. It is good also as a form.

FIG. 13 is a bottom view showing an application form of the embodiment shown in FIG. 3 in which four backside electrodes 10 are individually arranged on the backside 4 of the substrate body 2a of the wiring board 1a for each corner side of the backside 4. It is.
As shown in FIG. 13, on the back surface 4 of the substrate body 2a, four back electrodes 10 are individually formed for each corner side of the back surface 4 in the same manner as described above. One convex wiring 12 is formed on the back surface portion 4z between the long side 4a and the short side 4b of the back surface 4. Further, among the pair of left and right back electrodes 10 that are adjacent to each other along the pair of upper and lower long sides 4a on the back surface 4, in the upper left back electrode 10 and the lower right back electrode 10 in FIG. From the inner side on the back electrode 10 side adjacent to the right side toward the middle of the long side 4a, convex wirings 12a having an L shape in bottom view are formed point-symmetrically.
The pair of convex wirings 12a may be applied to the wiring boards 1b and 1c, and may be similarly applied to the back surface 4 shown in FIG.

FIG. 14 is a partial bottom view showing a part of a product region 21 in a multi-piece wiring board 20 having a plurality of wiring boards 1a adjacent to each other vertically and horizontally.
As shown in FIG. 14, in each of the back surfaces 4 of the substrate main bodies 2a of the plurality of wiring boards 1a divided by the boundaries 23 as described above, the individual back electrodes 10 positioned on the corner side of each back surface 4 Is electrically connected to the back surface electrode 10 of the wiring board 1a adjacent to each other by a connection wiring 32 that connects the middle of each pair of outer sides. Further, for each back surface 4 of the pair of wiring boards 1a adjacent to each other across the boundary 23 and each long side 4a, the inner sides of the pair of back surface electrodes 10 at the diagonal positions between the boundary 23 and the long side 4a. Between them, there is formed a connection wiring 33 that intersects the boundary 23 at a right angle in the middle and has a vertically long Z-shape or crank shape in plan view. The connection wiring 33 becomes the convex wiring 12a for each wiring board 1a when the multi-piece wiring board 20 is divided into a plurality of wiring boards 1a along the boundary 23 later.

By adding the connection wirings 33 as described above to the back surface 4 of the substrate body 2a for each wiring substrate 1a in the product area 21 of the wiring substrate 20, the plating current is applied to the back surface electrodes 10 of the plurality of wiring substrates 1a. Thus, it is possible to more reliably and uniformly energize the entire conductor portion.
In addition, the form which further forms a pair of convex wiring 12a with respect to a pair of back surface electrodes 10 in the said back surface 4 is applied to the said wiring boards 1b and 1c, and any one of these is multiply provided in the product area | region 21. A multi-piece wiring board 20 provided may be formed.

The present invention is not limited to the embodiments described above.
For example, the insulating material constituting the substrate body may be an epoxy resin or the like. The substrate body made of the resin is, for example, a so-called copper-clad resin substrate in which copper foil is bonded to both surfaces of a single-layer resin plate, a plurality of flat resin layers, or a flat resin layer and a rectangular frame-shaped frame. The form which laminated | stacked the shape resin integrally may be sufficient.
The substrate body may be formed by laminating a ceramic layer and a resin layer.
Furthermore, the front and back surfaces of the substrate body are not limited to the rectangular shape having a pair of long sides and short sides, but may be square shapes having substantially the same length on all four sides.
Further, the arc wall located at each corner of the board body may be omitted, and in this connection, the through hole in the multi-cavity wiring board may be omitted.
Further, the back electrode may be formed in such a manner that five or more (for example, six or eight) are separated from each other on the back surface of the substrate body.

In addition, the via conductor is individually formed at least one or more between the plurality of back surface electrodes and the frame-shaped conductor portion on the front surface side of the substrate body, but the total number of back surface electrodes formed on the back surface of the substrate body is In the case of three or more, at least one or more may be individually formed between the two back electrodes and the frame-shaped conductor portion.
Further, the convex wiring is not limited to a rectangular shape in the bottom view between the back electrode and each side of the substrate body (a part of the back surface), and is a long and narrow parallelogram (diagonal direction) in the bottom view. Alternatively, a curved shape or a trapezoidal shape may be adopted.
Further, the multi-piece wiring board may have a square product shape in plan view, and the outer shape and inner shape of the ear portion may be a frame shape substantially similar to the square shape.
In addition, the plating electrode and the plating wiring in the multi-cavity wiring board may be arranged every four sides of the ear portion.

  According to the present invention, various electronic components such as a crystal resonator can be mounted on the surface of the substrate body in a sealable manner, the surface of the conductor exposed to the outside is reliably covered with the metal plating film, and mounted on the motherboard. In some cases, it is possible to reliably provide a wiring board in which defects on the back electrode hardly occur and a multi-piece wiring board having a plurality of wiring boards.

1a to 1c ……………… Wiring boards 2a to 2c ……………… Board body 3, 3b …………………… Front side 4 ………………………… Back side 4a ………… …………… long side (side)
4b ……………………… Short side (side)
4z ………………………… Part of the back surface 7 ………………………… Metal ring (frame-shaped conductor)
9 ………………………… Via conductor 10, 10a, 10b ... Back electrode 12, 12a …………… Convex wiring 14 ……………………… Frame metallization layer (frame conductor) Part)
20 ……………………… Multiple wiring board 21 ……………………… Product area 22 ………………………… Ear part 26 ……………………… Plating Electrode 28 ………………………… Plating wiring 32, 33 ……………… Connection wiring

Claims (4)

A substrate body made of an insulating material and having a rectangular front surface and a back surface in plan view;
A plurality of back surface electrodes formed on the back surface of the substrate body;
A frame-shaped conductor portion that is disposed on the surface side of the substrate body and has a rectangular frame shape in plan view;
A wiring board comprising a via conductor that penetrates the substrate body and conducts between the plurality of back surface electrodes and the frame-shaped conductor portion,
A part of the back surface is exposed between the plurality of back surface electrodes and each side of the back surface of the substrate body,
On the back surface of the substrate body, at least one or more convex wirings are formed between the plurality of back surface electrodes and a pair of sides intersecting each other.
A wiring board characterized by that. The plurality of back surface electrodes are formed at four corners on the back surface of the substrate body on each corner side, and each back surface electrode has at least one or more of a pair of sides intersecting each other on the back surface. Forming the convex wiring,
The wiring board according to claim 1. A product region in which a plurality of wiring boards according to claim 1 or 2 are arranged adjacent to each other along a vertical and horizontal direction in a plan view,
It is made of the same insulating material as the substrate body, has a front surface and a back surface, surrounds the periphery of the product region, and an ear portion having a rectangular frame shape in plan view;
A plurality of plating electrodes formed around the ears;
A multi-cavity wiring board comprising: a plating wiring that conducts between the electrode for plating and the convex wiring for each wiring board located on a peripheral side of the product region,
In the product region, a pair of wiring boards adjacent to each other across the boundary are electrically connected via a connection wiring that includes the pair of convex wirings and straddles the boundary.
A multi-piece wiring board characterized by that. On the surface side of the product region, along the boundary that divides a plurality of wiring boards, a dividing groove having a lattice shape in plan view is formed.
The multi-piece wiring board according to claim 3, wherein:

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