JP2015138828A - Multi-piece wiring board, wiring board and manufacturing method of multi-piece wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-piece wiring board which can suppress occurrence of burrs and cracks and disconnection of a side conductor during division and to provide a wiring board and a manufacturing method of the multi-piece wiring board.SOLUTION: A multi-piece wiring board includes: a plurality of wiring board regions 102; and a mother board 101 in which division grooves 106 are arranged along a boundary 105 of the wiring board regions 102. The mother board 101 is penetrated in a thickness direction at a part of the division groove 106 and a step part 107a is arranged on an inner peripheral face. A first portion 108 closer to a first main face 103 compared to the step part 107a includes a through hole 107 with a diameter smaller than a second portion 109 close to a second main face 104. An intra-through hole division groove 106a, which is overlapped with the division groove 106 in planar view, is formed on the step part 107a. Vertical grooves 106b are formed from the division groove 106 to the intra-through hole division groove 106a on inner faces in the first portion 108 and the second portion 109 of the through hole 107.

Description

  The present invention relates to a multi-cavity wiring board in which a plurality of wiring board regions having electronic component mounting portions are arranged vertically and horizontally on a mother board, a wiring board manufactured from the multi-cavity wiring board, and a multi-cavity wiring The present invention relates to a method for manufacturing a substrate.

  Conventionally, wiring boards used for mounting electronic components such as semiconductor elements and surface acoustic wave elements are electronic components on insulating substrates made of ceramic sintered bodies such as aluminum oxide sintered bodies and glass ceramic sintered bodies. It has a mounting part for mounting. The insulating substrate is generally composed of a square flat plate-like base portion and a square frame-like frame portion laminated on the upper surface of the base portion so as to surround the mounting portion. After the electronic component is mounted on the mounting portion, a lid is joined to the upper surface of the frame portion, and the mounting portion is hermetically sealed.

  Such a wiring board is generally manufactured in the form of a so-called multi-cavity wiring board in which a plurality of wiring boards are obtained simultaneously from a single large-area mother board. In the multi-cavity wiring board, a plurality of wiring board regions are arranged vertically and horizontally on a mother board made of, for example, an aluminum oxide sintered body. A dividing groove is formed in the main surface such as the upper surface of the mother board along the boundary of the wiring board region. A bending stress is applied to the mother board across the dividing groove, and the mother board is broken, so that it is divided into individual wiring boards. The dividing grooves are formed, for example, by cutting the upper and lower surfaces of the unfired mother board with a predetermined depth along the outer periphery of the wiring board region using a cutter blade or the like (see Patent Document 1). .

  In this multi-piece wiring board, a plurality of through-holes straddling the outer periphery of the wiring board region may be formed. These through holes act as spaces for providing side conductors for electrically connecting the wiring conductors in the wiring board regions adjacent to each other, for example.

  Further, it is known that these through-holes are smaller in size (diameter and the like) in plan perspective than on the base side on the frame side. In this case, the joint area of the lid to the frame can be increased by relatively reducing the size of the through hole (size of the opening) on the side of the frame where the lid is joined to the upper surface. In addition, the step part according to the magnitude | size of the said plane see-through | perspective is contained in the inner surface of the through-hole.

Japanese Patent Laid-Open No. 2002-11718 JP 2010-153423 A

  However, there is a possibility that the following problems occur in the conventional multi-cavity wiring board. That is, since it is difficult to insert the cutter blade into the through-hole, a split groove is formed only on one main surface (for example, the upper surface) of the mother board in a portion of the mother board that overlaps the stepped part in the through-hole in a plan view. The formed form is formed, and the division of the mother substrate is deteriorated in this portion. Due to the deterioration of the division property, defects such as chipping and burrs in the divided wiring board are likely to occur.

  A multi-cavity wiring board according to one aspect of the present invention includes a dividing groove provided to face the first main surface and the second main surface along a boundary of the wiring board region, and the dividing groove The portion having the groove penetrates the mother substrate in the thickness direction and includes a step portion on the inner peripheral surface, and the second portion in the first portion closer to the first main surface than the step portion. A plurality of through-holes having a smaller diameter than the second portion close to the main surface, and a through-hole split groove that overlaps the split groove in a plan view is provided on the stepped portion. A vertical groove extending from the dividing groove to the through hole dividing groove is provided on an inner surface of the first part and the second part of the through hole.

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

  According to one aspect of the present invention, there is provided a method for manufacturing a multi-cavity wiring board, wherein a mother board having a first main surface and a second main surface opposite to the first main surface is manufactured, and A step of providing a plurality of arranged wiring board regions; and straddling the outer periphery of the wiring board region in the mother board and penetrating from the first main surface to the second main surface; Forming a through-hole having a smaller diameter in the first portion on the surface side than the second portion on the second main surface side, and the first main surface and the first of the mother board along the outer periphery of the wiring board region Forming a split groove on the two principal surfaces by laser processing, forming a split groove in the through hole by laser processing on a step portion between the first portion and the second portion in the through hole; It is characterized by providing.

  According to the multi-cavity wiring board of one aspect of the present invention, it is possible to provide a multi-cavity wiring board in which the generation of burrs and chips when the mother board is divided into individual pieces is suppressed. That is, a through-hole split groove that overlaps the split groove in a plan view is provided on the stepped portion, and extends from the split groove to the through-hole split groove on the inner surface of the first portion and the second portion of the through hole. Since the vertical groove is provided, the mother substrate can be easily broken from the dividing groove on the main surface of the mother substrate to the through hole dividing groove. For example, when the bottom of the split groove on the first main surface of the mother substrate is the starting point of the crack, the progressing crack is easily guided to the split groove on the step portion along the vertical groove of the first portion. Further, in the second portion, the crack that has progressed from the stepped portion is easily guided to the dividing groove formed on the second main surface of the mother substrate by the vertical groove of the second portion. For this reason, generation | occurrence | production of the burr | flash and chipping | chip at the time of dividing | segmenting a mother board into a piece is suppressed.

  According to the wiring board of one aspect of the present invention, since the multi-cavity wiring board having the above-described configuration is divided for each wiring board region, it is possible to suppress the occurrence of burrs and chips on the outer periphery. A wiring board excellent in accuracy and the like can be provided.

  According to the method for manufacturing a multi-cavity wiring board of one aspect of the present invention, since the above-described steps are included, a wiring board with excellent outer dimensional accuracy in which the occurrence of burrs and chips on the outer periphery is suppressed. A manufacturing method that can be manufactured can be provided.

  That is, by forming the dividing groove on the mother substrate by laser processing, the dividing groove can always be formed at a predetermined depth also on the bottom surface of the through hole in which the step portion is formed. Furthermore, when the laser beam passes through the boundary of the wiring board region, vertical grooves are easily formed on the inner side surface of the first portion of the through hole and the inner side surface of the second portion. Therefore, a multi-piece wiring board having the above configuration can be easily manufactured.

(A) is a top view which shows the multi-piece wiring board of embodiment of this invention, (b) is sectional drawing in the A-A 'line of (a). (A) is a principal part enlarged bottom view which shows the multi-piece wiring board of embodiment of this invention, (b) is sectional drawing in the X-X '. (A) is the principal part expansion bottom view which shows the principal part in the 1st modification of the multi-piece wiring board shown in FIG. 1, (b) is the sectional drawing in the Y-Y '. (A) is a principal part enlarged top view which shows the principal part in the 2nd modification of the multi-piece wiring board shown in FIG. 1, (b) is sectional drawing in the Z-Z '. It is a top view which shows the wiring board of embodiment of this invention. It is a top view which shows the principal part in the manufacturing method of the multi-cavity wiring board of embodiment of this invention.

  A multi-cavity wiring board, a wiring board, and a manufacturing method of the multi-cavity wiring board of the present invention will be described with reference to the accompanying drawings.

  FIG. 1A is a top view showing a multi-piece wiring board according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line A-A ′ of FIG. 2A is an enlarged bottom view showing the main part of the multi-cavity wiring board shown in FIG. 1, and FIG. 2B is a cross-sectional view taken along line XX ′ in FIG. It is sectional drawing. 3A is an enlarged bottom view showing the main part of the first modification of the multi-cavity wiring board shown in FIG. 1, and FIG. 3B is a plan view of FIG. It is sectional drawing in a YY 'line. FIG. 4A is an enlarged top view showing a main part in the second modification of the multi-cavity wiring board shown in FIG. 1, and FIG. 4B is a Z view in FIG. It is sectional drawing in -Z '. FIG. 5 is a top view showing an example of a wiring board obtained by dividing the multi-cavity wiring board shown in FIG. 1 into wiring board regions. FIG. 6 is a bottom view schematically showing an enlarged main part in the manufacturing method of the multi-cavity wiring board shown in FIG.

1 to 6, reference numeral 101 denotes a mother board, 102 denotes a wiring board region, 103 denotes a first main surface of the mother board, 103a denotes a first insulating layer, 104 denotes a second main surface of the mother board, and 104a denotes second insulating. Layer, 105 is a boundary of the wiring board region, 106 is a dividing groove, 106a is a dividing groove in the through hole, 106b is a vertical groove, 107 is a through hole, 107a is a stepped portion, 108 is a first portion of the through hole, 109 is a through hole Second portion of hole, 110 is mounting portion, 111 is a frame-like metallized layer, 112 is a wiring conductor, 113 is a side conductor, 114 is a disposal margin region, 115 is a terminal for plating, 116 is a laser beam, 117 is a penetration portion, 118 is an external connection conductor, 202 is a wiring board, 208 is a recess, and 209 is a groove.

A plurality of wiring board regions 102 having mounting portions 110 are vertically and horizontally formed on a mother board 101 in which a first insulating layer 103a having a plurality of through portions (not shown) and a flat second insulating layer 104a are laminated. As well as being arranged. The through portion of the first insulating layer 103a is a portion that forms a frame portion of an individual wiring board described later. In the following description, the first insulating layer 103a may be a frame shape or the like. A dividing groove 106 is formed along the boundary 105 of the wiring board region 102 on the first main surface (upper surface in the present embodiment) of the mother board 101, so that a multi-piece wiring board is basically configured.

Such a mother substrate 101 is divided along the boundary 105 of the wiring substrate region 102, and for example, an individual wiring substrate as shown in FIG. 5 is manufactured. The wiring board to be produced is formed by placing the frame-shaped metallized layer 111 on the insulating substrate 202 in which the frame-shaped first insulating layer 103a is laminated on the upper surface of the second insulating layer 104a.
In addition, a wiring conductor 112 and the like are provided and basically configured.

The mother substrate 101 is made of, for example, a ceramic sintered body such as an aluminum oxide sintered body, a glass ceramic sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a silicon nitride sintered body, or a mullite sintered body. It is formed by ligation.

In the example of this embodiment, as shown in FIG. 1 and the like, a margin area 114 is provided on the outer periphery of the mother board 101 so as to surround the plurality of wiring board areas 102 arranged. The disposal allowance area 114 is provided for facilitating handling of the multi-piece wiring board. Also, plating terminals 115 are provided on opposite sides of the disposal allowance region 114 in order to deposit electrolytic plating on the wiring conductor 112 and the like of each wiring board region 102.

The mother substrate 101 is produced, for example, by integrally firing the first and second insulating layers 103a and 104a. That is, a plurality of ceramic green sheets are produced by adding a suitable organic solvent and binder to a raw material powder containing glass components such as aluminum oxide and silicon oxide to form a plurality of ceramic green sheets. After forming into a frame shape by laminating a frame-shaped ceramic green sheet on a flat ceramic green sheet that has not been punched and firing this laminate integrally, the first and second insulation A mother substrate 101 in which the layers 103a and 104a are stacked can be manufactured.

The plurality of wiring board regions 102 arranged on the mother board 101 have a concave mounting part 110 for electronic components (not shown) at the center or the like on the first main surface 103. Each wiring board region 102 is a region to be an individual wiring board. Each wiring board region 102 has a form in which a frame-like first insulating layer 103a is laminated on the upper surface of a flat plate-like second insulating layer 104a. The frame-shaped first insulating layer 103a is for protecting electronic components mounted on the mounting portion 110.

Examples of electronic components mounted on the mounting unit 110 include various types of piezoelectric elements such as crystal oscillators, surface acoustic wave elements, semiconductor elements such as semiconductor integrated circuit elements (ICs), capacitive elements, inductor elements, resistors, and the like. Mention electronic components.

A wiring conductor 112 is formed on the inside and the surface of the mother board 101 from the mounting portion 110 to the lower surface of the mother board 101. A portion of the wiring conductor 112 formed on the lower surface of the mother substrate 101 is located, for example, on the outer peripheral portion of the lower surface of each wiring substrate region 102. Of the wiring conductors 112, those formed inside the mother board 101 (not shown) are in the form of so-called via conductors or internal wiring layers. When the electronic component mounted on the mounting unit 110 is electrically connected to the wiring conductor 112, the electronic component is electrically connected to an external electric circuit via the wiring conductor 112.

The wiring conductor 112 is made of, for example, copper, silver, palladium, gold, platinum, tungsten, molybdenum,
Made of a metal material such as manganese. If the wiring conductor 112 is made of, for example, molybdenum, a metal paste (not shown) prepared by adding an organic solvent and a binder to molybdenum powder is applied in a predetermined pattern to a ceramic green sheet serving as the base substrate 101. In addition, it can be formed by simultaneous firing.

  A wiring board produced by dividing a multi-piece wiring board having such a configuration into pieces is mounted with, for example, a piezoelectric vibration element as an electronic component, a communication device such as a mobile phone or a car phone, a computer, and an IC card. It is used as an oscillator that serves as a reference for frequency and time in electronic equipment such as information equipment.

In order to divide the mother board 101, dividing grooves 106 are formed in the first main surface 103 and the second main surface 104 of the mother board 101 along the outer periphery of the wiring board region 102. The portion where the dividing groove 106 is formed (
By applying stress to the mother board 101 at the boundary 105) of the wiring board region 102 and breaking the mother board 101 in the thickness direction, the mother board 101 is divided into individual wiring boards.

A frame-like metallized layer 111 is formed on the upper surface of each wiring board region 102 in contact with the dividing groove 106. A lid (not shown) is bonded to the frame-shaped metallized layer 111, and the mounting portion 110 is sealed. In the example of this embodiment, a nickel plating layer and a gold plating layer (not shown) are sequentially deposited on the upper surface of the frame-like metallized layer 111.

The frame-like metallized layer 111 is made of a metal such as tungsten or molybdenum. For example, if the frame-like metallized layer 111 is composed of a molybdenum metallized layer, a metal paste produced by adding an organic solvent, a binder, etc. to a molybdenum powder is used as a ceramic green as a ceramic insulating layer (the frame part). It can be formed by printing in a predetermined pattern on the upper surface of the sheet. The metal paste is, for example, a frame-like metallized layer 111 after firing.
Is formed to have a thickness of about 8 to 20 μm.

In addition, a plating layer of nickel or the like covering the frame-shaped metallized layer 111 is formed to prevent oxidative corrosion of the frame-shaped metallized layer 111, and to improve wettability and strengthen bonding strength when brazing, which will be described later. It is a thing. For example, the plating layer preferably has a two-layer structure in which a nickel plating layer is formed on the lower side and a gold plating layer is formed on the upper side. Here, it is preferable that the metal plating film is formed thin from the viewpoint of cost, the nickel plating layer is formed to about 2 to 10 μm, and the gold plating layer is formed to about 0.1 to 1.0 μm. These metal plating films can be formed, for example, by supplying a plating deposition current to the portion to be plated (the surface of the frame-like metallized layer 111) and performing electrolytic plating in a plating solution.

With respect to the mother substrate 101, a through hole 107 that penetrates the mother substrate 101 in the thickness direction is provided at a portion where the dividing groove 106 is provided. The through-hole 107 is, for example, a portion where a metallized layer (not shown) is attached to the inner peripheral surface thereof and a terminal for external connection or the like is provided on a piece of wiring board.

The through hole 107 includes a stepped portion 107a on its inner peripheral surface. Further, the through hole 107 has a smaller diameter in the first portion 108 closer to the first main surface 103 than in the stepped portion 107 a than in the second portion 109 close to the second main surface 104.

In other words, the through hole 107 has the first main surface 103 on which the frame-shaped metallized layer 111 is provided.
Is smaller than the opening of the second main surface 104 on the opposite side. Thereby, for example, a through hole 107 penetrating the mother substrate 101 is realized while sufficiently securing a sealing region in the first main surface 103. Since the through-hole 107 penetrates the mother substrate 101 in the thickness direction, for example, the plating solution can easily flow into and out of the through-hole 107 when a plating layer is deposited on the inner peripheral surface of the through-hole 107. It is easy to deposit the plating layer.

Further, in the through-hole 107, an in-through-hole dividing groove 106a that overlaps the dividing groove 106 in a plan view is provided on the step portion 107a. Further, a longitudinal groove 106b extending from the dividing groove 106 to the through hole dividing groove 106a is provided on the inner surface of the first portion 108 and the second portion 109 of the through hole 107. The step 107 a is a surface portion of the step 107 a that can be seen from the outside in the bottom view of the mother substrate 101, and is a surface parallel to the first and second main surfaces 103 and 104.

With such a structure, it is possible to provide a multi-piece wiring board in which generation of burrs and chips when the mother board 101 is divided into individual pieces is suppressed. That is, the through-hole inner dividing groove 106 a is provided, and the vertical groove 106 b is provided on the inner surface of the first portion 108 and the second portion 109 of the through-hole 107. The mother substrate 101 can be easily broken from the surface dividing groove 106 to the through-hole dividing groove 106b.

For example, when the bottom of the split groove 106 on the first main surface 103 of the mother substrate 101 is the starting point of the crack, the progressing crack is divided along the vertical groove 106b of the first portion 108 on the step groove 107a. Easy to be guided to. Further, in the second portion 109, the crack that has progressed from the stepped portion 107 a is easily guided to the dividing groove 106 formed in the second main surface 104 of the mother substrate 101 by the vertical groove 106 b of the second portion 109. For this reason, generation | occurrence | production of the burr | flash and chipping | chip at the time of dividing | segmenting the mother board | substrate 101 into a piece is suppressed.

As a method of forming the dividing groove 106, the through-hole dividing groove 106a, and the vertical groove 106b, for example, a processing method (laser processing) using laser light (hereinafter simply referred to as laser) can be used. As a feature of laser processing, since it is non-contact processing and division grooves can be formed without applying mechanical stress, deformation of the wiring board region 102 can be prevented, and even if the surface height of the workpiece changes, processing It is mentioned that the dividing groove 106 along the line can be formed. That is, the laser is continuously irradiated along the boundary of the wiring board region 102 from the second main surface 104 of the mother board 101 to the stepped portion 107a on the inner peripheral surface of the through hole 107, and FIG. Are formed, through-hole divided grooves 106a and vertical grooves 106b.

A split groove 106 is first formed in the second main surface 104 by the laser irradiated to the second main surface 104. Subsequently, since the laser is irradiated along the inner surface of the second portion 109, a vertical groove 106b is formed on the inner surface in the vertical direction. Further, since the stepped portion 107a is irradiated with laser, the through-hole divided groove 106a is formed on the stepped portion 107a. In this case, since the laser irradiation position is linear in plan view, the through-hole divided groove 106a and the divided groove 106 on the upper surface of the mother substrate 101 overlap each other. Further, since the laser is continuously irradiated along the boundary of the wiring board region 102, the laser is also irradiated to the inner surface of the first portion 108 in the vertical direction, and the inner surface of the first portion 108 is also vertically A groove 106b is formed.

Further, since the laser is sequentially irradiated along the boundary of the wiring board region 102 continuously, the opposite side of the through hole 106 is also longitudinally formed on the inner surface of the first portion 108 by the reverse process described above. A groove 106b, a through-hole divided groove 106a, a vertical groove 106b on the inner surface of the second portion 109, and a divided groove 106 on the second main surface 104 are formed in this order.

A dividing groove 106 is also formed on the first main surface 103 side by a laser. When forming the dividing grooves 106 and the like by laser from the first main surface 103 side, the first portion 108 is formed from the second main surface 104 side.
It is desirable to perform alignment with the vertical groove 106b formed on the side surface of this. Since the vertical groove 106b is formed in a V shape in the same manner as the dividing groove 106, the vertical groove 106b includes a vertical groove 106b on the first main surface 103 side and a vertical groove 106b on the second main surface 104 side. In the overlapping portion in the side view, the width is the narrowest and shallowest.

The width and depth of the dividing groove 106 can be appropriately adjusted according to the output of the laser. The irradiation position of the laser is appropriately adjusted by, for example, an alignment system using an image processing apparatus.

The division grooves 106, the through-hole division grooves 106a and the vertical grooves 106b can be formed not only by laser processing but also by mechanical processing using a cutter blade. In this case, a blade having a special shape that can be deeply inserted into the through hole 107 and can be cut obliquely with respect to the inner surface of the first portion 108 and the second portion 109 can be used. Good.

FIG. 3 shows a first modification of the multi-cavity wiring board shown in FIGS. 1 and 2. The multi-cavity wiring board further includes a side conductor 113 formed on the inner side surface of the through hole 107 in the first modification. The bottom of the longitudinal groove 106b is located in the side conductor 113. The side conductor 113 is a portion that electrically connects the wiring conductors 112 of the wiring board regions 102 adjacent to each other, for example. In this case, since the side conductor 113 is not cut by the dividing groove 106, the electrical connection between the wiring conductors 112 of the wiring board regions 102 adjacent to each other can be easily ensured. That is, even after the division grooves 106 and the vertical grooves 106b are formed, the wiring conductors 112 of the wiring board regions 102 adjacent to each other are maintained in the state of being electrically connected by the side conductors 113. The vertical groove 106b in this case can also be formed by, for example, the same laser processing as in the above-described embodiment.

When the dividing groove 106 is formed by laser processing, as shown in FIG. 2B, the dividing groove 106 becomes gradually narrower from the second main surface 104 toward the stepped portion 107a, and the first main surface is also reduced. It gradually narrows from the surface 103 toward the stepped portion 107a. Further, the dividing groove 106 on the first main surface 103 side and the longitudinal groove 106b on the inner side surface of the first portion 108 continuous with the dividing groove 106 gradually increase from the vicinity of the center in the thickness direction of the first insulating layer 103a to the stepped portion 107a. Formed. This is because in the laser processing, the dividing groove 106 is formed in a substantially V-shaped vertical section, and the vertical groove 106b has a processing trace that remains along the V-shape.

In addition, the vertical groove 106b formed in the side conductor 113 formed on the inner side surface of the second portion 109 has a second shape.
It is formed only by laser processing from the main surface 104 side, and is not formed by laser processing from the first main surface 103 side. This is because the laser irradiated from the first main surface 103 side is blocked by the first insulating layer 103a where the stepped portion 107a is formed, so that the laser from the first main surface 103 side is not irradiated to the side conductor 113. It is. Therefore, the formation of the stepped portion 107a in the through hole 107 ensures the electrical connection between the wiring substrate regions 102 adjacent to the side conductor 113, and the dividing groove 106
It is effective to make a structure that is not cut by.

  In this example, when the frame-like metallized layer 111 is grounded, for example, it may be connected to a ground conductor (not shown) provided on the mother board 101. In this modification, the wiring conductors 112 of the wiring board regions 102 adjacent to each other are connected to the mother board 101 by connecting the side conductors 113 and the frame-like metallized layer 111 between the wiring board regions 102. All the wiring substrate regions 102 arranged are electrically connected to each other.

  The wiring conductor 112 is electrically led out to the second main surface 104 from the mounting portion 110 through the inside of the wiring board region 102 and the outer peripheral side surface, and is electrically connected to the external connection conductor 118 formed on the second main surface 104. It is connected. In this example, the wiring conductor 112 and the frame-like metallized layer 111 are formed so as to be separated from each other, and the side conductor 113 is formed on the side surface of the second portion 109.

The state of the vertical groove 106b formed in the second portion 109 may affect the electrical connection state between the wiring conductors 112 of the wiring board regions 102 adjacent to each other. For example, even when the depth of the dividing groove 106 formed on the second main surface 104 side does not exceed the thickness of the second insulating layer 104a, when the vertical groove 106b is formed to exceed the thickness of the side conductor 113, Side conductor 113 is cut vertically (disconnected)
To do. Therefore, the electrical connection state by the side conductors 113 between the wiring conductors 112 of the adjacent wiring board regions 102 cannot be maintained. Therefore, the vertical groove 106b does not exceed the thickness of the side conductor 113 in the thickness direction of the second insulating layer 104a so that the electrical connection state between the wiring conductors 112 of the adjacent wiring board regions 102 can be maintained. Formed with. In other words, it is necessary to prevent the region where the side conductor 113 remains at the boundary 105 between the adjacent wiring board regions 102 from being interrupted. The side conductor 113 is formed with a thickness of about 10 to 20 μm, for example.

Examples of the method of forming the side conductor 113 include a method in which a metallized paste that becomes the side conductor 113 is applied to the inner side surface of the through hole 107 of the ceramic green sheet that becomes the second insulating layer 104a and is fired simultaneously. Specifically, it is as follows. First, a ceramic green sheet is placed on a mounting table having a suction hole at a position corresponding to the through hole 107, and a printing mask having an opening that exposes the through hole 107 is placed on the upper surface of the ceramic green sheet. To do. Next, the metallized paste is supplied from above the printing mask into the through hole 107 by sliding the squeegee, and the metallized paste is sucked from the suction hole. The metallized paste can be applied to the inner surface of the through hole 107 through the above steps. The applied metallized paste is sintered after firing to form the side conductor 113 in the second portion 109. After the dividing groove 106, the through-hole dividing groove 106a, and the vertical groove 106b are formed,
The electrical connection state between the wiring conductors 112 is maintained. As a result, a metal such as a gold plating layer or a nickel plating layer is formed on the exposed surface of the wiring conductor 112 and other exposed conductors (not shown) formed in the plurality of wiring board regions 102 of the mother board 101 by electrolytic plating. A plating layer is formed. In this case, a plating layer is similarly formed on the exposed surface of the side conductor 113.

In the above description, the division grooves 106 and the through-hole division grooves 106a are formed before the plating process of the mother substrate 101, that is, the division grooves 106 and the like are formed in the laminate that becomes the mother substrate 101 before firing. However, the following effects can also be obtained when the dividing grooves 106 and the like are formed in the mother substrate 101 after the firing and plating steps. For example, when an electrical check or the like is performed on the wiring conductors 112 in a state where the wiring conductors 112 and the like of the adjacent wiring board regions 102 are electrically connected to each other, a plurality of wiring board regions 102 that are electrically connected are used. The wiring conductors 112 can be terminals having a common potential. Therefore, a multi-piece wiring board having a structure effective for improving workability such as an electrical check is obtained.

Further, the multi-piece wiring board of the embodiment has a frame-like metallized layer 111 formed on the first main surface 103 so as to surround the mounting portion 110. As described above, FIG. 4A is an enlarged top view showing the main part in the second modification of the multi-cavity wiring board shown in FIG. In the second modification, the frame-like metallized layer 111 includes a non-formed portion in a portion overlapping the stepped portion 107a of the through hole 107 in a plan view. In the case of such a structure, by employing laser processing, the first main portion is formed in the step portion 107a around the through-hole 107 where burrs and chips are likely to occur when the mother substrate 101 is divided into individual pieces. The dividing groove 106 of the surface 103 can be formed deeper. In this case, since the dividing groove 106 is deeper, the dividing property of the mother substrate is improved. That means
In a portion that overlaps the stepped portion 107a in a plan view, the frame-like metallized layer 111 does not exist on the first main surface 103 side. Therefore, the amount of direct laser irradiation on the mother substrate 101 is increased by the virtual thickness of the frame-like metallized layer 111 that does not exist during laser processing, and the dividing grooves 106 are formed deeply. Therefore, as described above, the division property of this portion is further improved, and the mother substrate 101
Can be more easily performed, and burrs and chips when the mother substrate 101 is divided into individual pieces can be more effectively suppressed.

As described above, the thickness of the metal layer 106 after firing is about 8 to 20 μm, and the frame-shaped metallized layer 111 overlaps the stepped portion 107a of the through hole 107 by an amount corresponding to the thickness of the metallized layer. The dividing groove 106 formed on the first main surface 103 side can be deepened.

An example in the case where the laser processing is after the plating layer is deposited on the mother substrate 101 (the wiring conductor 112 etc.) will be specifically described. For example, the nickel plating layer is formed with a thickness of about 2 to 10 μm, and the gold plating layer is formed with a thickness of about 0.1 to 1.0 μm. That is, the total thickness from the exposed surface of the gold plating layer to the surface of the frame-like metallized layer 111 (interface with the nickel plating layer) is about 10 to 30 μm. At this time, since the dividing groove 106 is formed deeper by the amount corresponding to the total thickness of the frame-shaped metallized layer 111, the gold plating layer, and the nickel plating layer, the division property of this portion (non-forming portion) is improved. It is possible to suppress burrs and chips when the mother substrate 101 is divided into individual pieces. In other words, the mother substrate 101 in this case is formed with a divided groove 106 having a depth of about 30 to 80 μm including the frame-like metallized layer 111, the nickel plating layer, and the gold plating layer.

Further, for example, when the frame-shaped metallized layer 111 and the side conductor 113 are separated from each other in the through-hole 107 or the like and have different electrical potentials, the frame-shaped metallized layer 111 and the side conductor 113 are electrically connected. Must not be short-circuited. Due to the miniaturization of the wiring board, the distance between the outer peripheral end of the frame-like metallized layer 111 and the side conductor 113 has become even smaller. In this way, it overlaps with the stepped portion 10a of the through hole 107 in plan view. Providing the non-formed portion in the existing portion also has an effect of reducing the possibility of a short circuit due to the flow of the brazing material when the lid is joined to the frame-like metallized layer 111.

Further, the multi-piece wiring board of the embodiment may include a portion penetrating from the dividing groove 106 provided on the first main surface 103 to the in-through hole dividing groove 106a. As described above, FIG.
(B) and (b) are a top view and a cross-sectional view showing, in an enlarged manner, main portions in the first modification of the multi-cavity wiring board shown in FIG. In the first modification, a penetrating portion 117 penetrating from the dividing groove 106 of the first main surface 103 to the in-through hole dividing groove 106a is included. In the example of FIG. 3, the dividing groove 106 of the first main surface 103 and the dividing groove 106 provided in the second portion 109 communicate with each other at the bottoms. In other words, it includes a portion in which the upper and lower divided grooves 106 are connected to each other vertically. In such a structure, the mother board 101
From the first main surface 103 side in the stepped portion 107a around the through-hole 107 (a portion overlapping the stepped portion 107a in a plan view) of the through hole 107 where burrs and chips are likely to occur when the substrate is divided into pieces. Does not crack. That is, the first main surface 103 in the portion of the through hole 107 that overlaps the stepped portion 107a has already penetrated the first insulating layer 103a, or the dividing groove 106 and the second main surface on the first main surface 103 side. Since the respective bottom portions communicate with the dividing groove 106 on the 104 side, it is possible to suppress burrs and chips when the mother substrate 101 is divided into individual pieces without considering the dividing property of this portion. .

Further, in the case where the penetrating portion 117 is included, for example, the mother board 101 has a valley (
The following advantages are obtained when each wiring board region 102 is divided into individual pieces by bending (applying a bending stress) so as to be on the concave side. That is, the corner portion of the wiring board is originally a portion that is easily subjected to the stress at the time of division, but the first portion 108 of the adjacent wiring board region 102 is suppressed from contacting by the through portion 117. The Therefore, the occurrence of burrs and chips in the first portion 108 is further effectively suppressed.

The division grooves 106 and the vertical grooves 106b are formed by laser processing as described above, for example. When the dividing groove 106 is formed by laser processing, the dividing groove 106 is formed partway through the second insulating layer 104a in the region of the second insulating layer 104a, as shown in the sectional view of FIG. The vertical groove 106b is formed so as to gradually narrow from the second main surface 104 to the stepped portion 107a. In the region of the first insulating layer 103a, the dividing groove 106 is formed from the first main surface 103 to the middle of the first insulating layer 103a. Further, the through-hole dividing groove 106a is formed from the step portion 107a to the middle of the first insulating layer 103a. As a result, at the time of forming the dividing groove 106 and the like, the stepped portion 107a already penetrates the first insulating layer 103a or is formed from the first main surface 103 side from the dividing groove 106 and the second main surface 104 side. The bottoms of the divided grooves 106 to be formed are in contact with each other. The reason for this structure is that in the laser processing, the dividing groove 106 is processed into a substantially V shape, and the shape of the dividing groove 106 and the vertical groove 106b is in a shape along the V shape. Because it remains.

Further, the depth of the dividing groove 106 on the first main surface 103 side is equal to or greater than the depth (length) of the first portion 108 (the dividing groove 106 on the first main surface 103 side penetrates to the stepped portion 107a. It may be in the form (not shown). For example, the depth of the dividing groove 106 depends on various conditions such as the thickness relationship (ratio of thickness) between the first insulating layer 103a and the second insulating layer 104a, the position of the wiring conductor, or the intensity of the laser (output of the laser processing apparatus). The length can be set variously. Therefore, for example, a configuration may be employed in which a dividing groove (not shown) is provided only on the first main surface 103 side or only on the second main surface 104 side, and this dividing groove penetrates to the stepped portion 7a.

If the dividing groove 106 on the first main surface side penetrates up to the stepped portion 107a, if a side conductor (not shown) is formed in the first portion 108, the side conductor is in the middle. Is cut by the dividing groove 106). Therefore, the wiring conductors 112 in the wiring board regions 102 adjacent to each other cannot be electrically connected by the side conductors. Therefore, in this case, the second insulating layer 104
It is desirable to form a side conductor 113 on the second part 109 of a. Further, in this case, it can be considered that the longitudinal groove 106b is included in the through portion 117.

The wiring board according to one aspect of the present invention is obtained by dividing the multi-piece wiring board (mother board 101) described in any one of the above into each wiring board region 102. With such a structure, it is possible to provide a wiring board excellent in external dimension accuracy and the like, in which the occurrence of burrs and chips on the outer periphery is suppressed. That is, it is a wiring board in which the occurrence of burrs and chips when the mother board 101 is divided into individual pieces is suppressed, and the first portion 108 and the second part formed at the outer peripheral corner of the wiring board.
The castellation consisting of the portion 109 has no burrs or chips and has excellent dimensional accuracy.

When the wiring board divided into individual pieces is aligned, for example, in a tray for packing or taping packing, the tray material and the taping material are prevented from being caught in the pockets and poorly inserted. Can be reduced. In addition, the positioning of the wiring board by chucking or the like when mounting an electronic component such as a piezoelectric vibration element on the mounting portion 110 can be firmly performed with the outer peripheral shape, and the mounting property of the electronic component can be improved.

An example of the wiring board according to the embodiment of the present invention is shown in FIG. In this example, a mounting portion 110 is provided on the upper surface of a rectangular plate-like insulating substrate 202 formed by dividing the mother substrate 101, and a pair of wiring conductors 112 are provided on the mounting portion 110. In addition, the entire surface of the first main surface 103 is covered with a frame-like metallized layer 111. Further, the insulating substrate 202 has grooves 209 (so-called castellations) at four locations on the outer peripheral corner portion thereof. At both ends of the castellation, for example, in the case of a wiring board in which the mother board 101 shown in FIG. 3 is a piece, the trace of the through portion 117 of the dividing groove 106 remains as a stepped recess 208. Yes. The recess 208 is located on the inner side (the mounting part 110 side) than the virtual extension line (not shown) of each side. And since there is no generation | occurrence | production of a burr | flash and a chip | tip and it is excellent in the external dimension precision, the wiring board excellent in the packing property and mounting property of a wiring board can be provided.

Further, for example, in the case of a wiring board (not shown) in which the mother board 101 shown in FIG. 4 is made into a piece, a pair of wiring conductors 112 are provided on the mounting portion 110 in the same manner as the wiring board described above. . Further, the frame-shaped metallized layer 111 has a non-formed portion in a portion overlapping with the stepped portion 107a around the castellation in a plan view. In a portion other than the non-formed portion, the frame-shaped metallized layer 111 covers the frame-shaped first main surface 103 surrounding the mounting portion 110. Also in this case, it is possible to provide a wiring board that is excellent in packing and mounting properties of the wiring board, similarly to the wiring board in which the mother board 101 shown in FIG.

Furthermore, since the frame-shaped metallized layer 111 has a non-formed part, the brazing material does not spread out in the non-formed part. There is an effect that the possibility of an electrical short circuit between the side conductor 113 and the frame-like metallized layer 111 due to the flow-out can be reduced. Here, in the example of FIG. 4, the non-formed portion is a portion that overlaps the step portion 107 a around the castellation in a plan view, but may be different from this. For example,
If a sufficient bonding area between the frame-shaped metallized layer 111 and the lid can be secured, a non-formation portion is provided on the mounting portion 107a side wider than the portion overlapping the step portion 107a around the castellation in a plan view. Also good.

  The manufacturing method of the multi-cavity wiring board according to the embodiment of the present invention includes, for example, each process described in the description regarding the multi-cavity wiring board.

That is, first, a mother substrate 101 having a first main surface 103 and a second main surface 104 opposite to the first main surface 103 is manufactured, and a plurality of wiring substrate regions 102 arranged on the mother substrate 101 are provided. . Next, a through-hole 107 is formed in the mother board 101 so as to extend over the outer periphery of the wiring board region 102 and penetrate from the first main surface 103 to the second main surface 104. As described above, the through hole 107 is formed so that the first portion 108 on the first main surface 103 side has a smaller diameter than the second portion 109 on the second main surface 104 side. Next, the division grooves 106 are formed on the first main surface 103 and the second main surface 104 of the mother substrate 101 along the outer periphery of the wiring substrate region 102 by laser processing. Next, the through-hole dividing groove 106a is formed on the stepped portion 107a between the first portion 108 and the second portion 109 in the through-hole 107 by laser processing.

  Since the manufacturing method of the multi-cavity wiring board of the embodiment includes the above-described steps, the multi-cavity wiring that can produce a wiring board with excellent outer dimensional accuracy in which the occurrence of burrs and chips on the outer periphery is suppressed. A method for manufacturing a substrate can be provided.

That is, by forming the dividing groove 106 in the mother substrate 101 by laser processing, the dividing groove 106 can be easily formed at a predetermined depth also on the stepped portion 107a in the through hole 107 in which the stepped portion 107a is formed. Further, when the laser 116 passes through the boundary 105 of the wiring board region 102, the longitudinal groove 106b can be easily formed on the inner side surface of the first hole 108 and the inner surface of the second portion 109 of the through hole 107. . Therefore, for example, a multi-piece wiring board having the configuration of the above embodiment can be easily manufactured.

FIG. 6 shows a laser processing step in the manufacturing method of the multi-cavity wiring board of the embodiment. FIG. 6 is an enlarged view of a main part when the upper surface of the through hole 107 is viewed from the second main surface 104 side of the mother substrate 101. FIG.
2 shows a state in which the inner surface of the through hole 107 is continuously irradiated with the laser 116 after the dividing groove 106 is formed in the second main surface 104 of the mother substrate 101 along the boundary 105 between the wiring substrate regions 102. ing.

  A division groove 106 is formed at the boundary 105 by the laser 116 irradiated between the wiring board regions 102 on the second main surface 104 side of the mother board 101. When the laser beam 116 is subsequently irradiated from the second main surface 104 to the stepped portion 107a, the laser 116 is also irradiated to the inner surface of the second portion 109 of the through hole 107, and the vertical groove 106b is formed on the inner surface. It is formed. Thereafter, the stepped portion 107a is irradiated with the laser 116, whereby the through-hole divided groove 106a is formed on the surface of the stepped portion 107a.

At this time, for example, when the dividing groove 106 is first formed on the first main surface 103 side, the laser 116 is formed from the bottom of the dividing groove 106 on the first main surface 103 side and the second main surface 104 side. Dividing groove 106 by
If they are connected to each other (if they communicate with each other vertically), a through portion 117 is formed on the inner surface of the first portion 108. Further, when the laser 116 is irradiated while moving from the stepped portion 107a beyond the end of the stepped portion 107a toward the center of the through hole 107 in plan view, the laser 116 follows the inner surface of the first portion 108. Is irradiated to form a vertical groove 106 b on the side surface of the first portion 108. As described above, the vertical groove 106b is included in the through portion 117.

  After that, the laser 116 moves and is irradiated from the through hole 107 to the stepped portion 107a and the second main surface 104. Similarly, the longitudinal groove 106b and the through-hole divided groove 106a are divided in the order reverse to the above-described order. A groove 106 is formed.

Here, as the laser 116 to be irradiated, for example, a laser having a wavelength in the ultraviolet region can be used. The laser 116 having a wavelength in the ultraviolet region has a solid-state laser pulse frequency of 10 to 200 kHz,
The pulse width is 5 ns or more and the processing point output is 1 to 100 W, preferably about 1 to 40 W. Some solid-state lasers having wavelengths in the ultraviolet region are excited by crystals such as YAG and YVO _4, and an optimum laser may be selected according to the respective pulse characteristics and workability of the workpiece.

On the other hand, in the case of a carbon dioxide laser, the thermal effect on the mother substrate 101 is so great that the groove is filled with the melt, and the split groove may not be formed in a good shape. Has a high absorptivity and low reflectivity for the frame-like metallized layer 111 and a metal plating film (not shown). In addition, since the absorbency is high with respect to the mother substrate 101, the V-shaped dividing groove 106 is formed even when irradiated from above the metal plating film covering the frame-like metallized layer 111 on the mother substrate 101 after the plating process. It can be formed with good shape.

  Further, the laser processing for forming the dividing groove 106 and the laser processing for forming the in-through hole dividing groove 106a are performed in the same process, and the depth of the dividing groove 106 and the depth of the in-through hole dividing groove 106a are set to the same depth. You may do it.

In this case, when forming the dividing groove 106 on the mother board 101 on which the wiring board on which the stepped portion 107a is formed is formed, the through-hole dividing groove 106a can be surely formed on the surface of the stepped portion 107a, and the outer periphery Thus, it is possible to provide a manufacturing method capable of manufacturing a wiring board with excellent outer dimensional accuracy in which occurrence of burrs and chips is suppressed.

That is, by forming the dividing groove 106 in the mother substrate 101 by laser processing, the bottom surface of the through hole 107 in which the stepped portion 107a is formed is formed in the same manner as the depth of the dividing groove 106 formed in the second main surface 104. Also, the dividing groove 106 can be formed. The dividing groove 106 can be made to have the same depth in this way because the dividing groove 106 can be processed by being irradiated even inside the stepped portion 107 a where the laser 116 is recessed, and the first substrate constituting the mother substrate 101 is formed. Since the second insulating layer 104a (insulating layer constituting the base portion) is formed thinner than the insulating layer 103a (insulating layer constituting the frame portion), the height irradiated with the laser 116 is difficult to change. This is because the processing state of the dividing groove by the laser 116 on the second main surface 104 and the processing state of the dividing groove by the laser 116 on the main surface of the stepped portion 107a are hardly changed. Even in this step, the vertical groove 106b is formed on the inner surface of the first portion 108 of the through hole 107 and the inner surface of the second portion 109.

Note that the multi-cavity wiring board, the wiring board, and the manufacturing method of the multi-cavity wiring board of the present invention are not limited to the examples of the embodiments described above, and various methods are possible without departing from the gist of the present invention. You can make any changes. For example, in the example of the above embodiment, the mother board 101
Is composed of a total of two insulating layers, one first insulating layer 103a and one second insulating layer 104a, but the mother substrate 101 may be composed of three or more insulating layers. Further, the frame-like metallized layer 111 of the wiring board is formed by depositing a nickel plating layer and a gold plating layer on the upper surface, but the metal layer 106 is formed on the deposited plating layer, for example, iron-nickel-cobalt. A metal frame (not shown) made of an alloy may be joined. Further, although the laser type of the laser processing apparatus is a YAG laser, the laser processing conditions may be appropriately changed using other lasers according to the required shape of the dividing groove 106.

101 ... Mother board
102 ・ ・ ・ Wiring board area
103 ... 1st main surface
103a ... 1st insulating layer (frame part)
104 ... 2nd main surface
104a ... second insulating layer (base)
105 ... Boundary
106 ・ ・ ・ Dividing groove
106a ・ ・ ・ Dividing groove in the through hole
106b ・ ・ ・ Vertical groove
107 ... through hole
107a ... Step part
108 ... 1st part (small diameter)
109 ... 2nd part (large diameter)
110 ・ ・ ・ Mounting part
111 ・ ・ ・ Frame metallization layer
112 ・ ・ ・ Wiring conductor
113 ・ ・ ・ Side conductor
114 ... Disposal area
115 ... Plating terminal
116 ... Laser (laser light)
117 ・ ・ ・ Through hole
118 ・ ・ ・ External connection conductor
202 ・ ・ ・ Insulating substrate
208 ... dent
209 ... Groove (Castellation)

Claims (6)

A first main surface and a second main surface opposite to the first main surface, and a mother board on which a plurality of wiring board regions are arranged;
The mother board has a dividing groove provided so as to face the first main surface and the second main surface along a boundary of the wiring board region;
The portion provided with the dividing groove penetrates the mother substrate in the thickness direction and includes a step portion on the inner peripheral surface, and the first portion closer to the first main surface than the step portion has the step. A plurality of through holes having a smaller diameter than the second portion close to the second main surface;
On the stepped portion, a through-hole split groove that overlaps the split groove in a plan view is provided,
A multi-cavity wiring board, wherein a longitudinal groove extending from the dividing groove to the through-hole dividing groove is provided on an inner surface of the first part and the second part of the through-hole. The multi-sided wiring board according to claim 2, further comprising a side conductor formed on an inner side surface of the through hole, wherein a bottom portion of the vertical groove is located in the side conductor. . The first main surface further includes a frame-like metallized layer provided on an outer peripheral portion of the wiring board region, and the frame-like metallized layer overlaps the stepped portion of the through hole in a plan view. The multi-cavity wiring board according to claim 1, further comprising a non-forming portion. 4. The multiplicity according to claim 1, further comprising a through portion in which a bottom portion of the division groove and a bottom portion of the through-hole division groove communicate with each other. Wiring board. 5. The wiring board according to claim 1, wherein the multi-cavity wiring board according to claim 1 is divided for each wiring board region. A plurality of ceramic insulating layers stacked on each other are formed, and a mother substrate having a first main surface and a second main surface opposite to the first main surface is manufactured and arranged on the mother substrate. Providing a plurality of wiring board regions;
The main board extends over the outer periphery of the wiring board region and penetrates from the first main surface to the second main surface, and the second main surface side in the first portion on the first main surface side Forming a through hole having a smaller diameter than the second part of
Forming a dividing groove by laser processing on the first main surface and the second main surface of the mother substrate along the outer periphery of the wiring board region; and the first portion and the second in the through hole A step of forming a through-hole split groove by laser processing on the stepped portion between the parts;
A method of manufacturing a multi-piece wiring board, comprising:

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