JP2015060976A - Multi-piece wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-piece wiring board which can keep good positioning property and good electrical conductivity even when downsizing of a wiring board region progresses.SOLUTION: A multi-piece wiring board comprises: a first notch 107 which is provided on a lateral face of a mother board 101 and extend in a vertical direction; a division groove 106 which is provided on a top face of the mother board 101 and extends from the first notch 107 in a direction along an outer edge of a wiring board region 102; and a second notch 108 which is provided on the mother board 101 in a part of a surface part of the first notch 107 and has a diameter smaller than that of the first notch 107 in planar view, in which an end of the division grove 106 lies in the second notch 108. Since a projection part is inhibited from going beyond an internal face of the first notch 107, favorable positioning and favorable electrical conductivity with reference to the first notch 107 of the mother board 101 can be performed.

Description

  The present invention relates to a multi-piece wiring board in which a plurality of wiring board regions having electronic component mounting portions are arranged vertically and horizontally on a mother board.

  Conventionally, wiring boards used for mounting electronic components such as semiconductor elements and surface acoustic wave elements include an insulating substrate made of a ceramic sintered body such as an aluminum oxide sintered body or a glass ceramic sintered body. The main surface of the insulating substrate has a mounting portion for mounting electronic components.

  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. In addition, a cutout portion is formed on the outer periphery of the multi-piece wiring board for positioning, for example, for mounting an electronic component with respect to the mounting portion, or for forming a terminal for enabling electrical conduction during plating. ing.

  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 a predetermined depth on the upper and lower surfaces of an unfired mother board using a cutter blade at the boundary between adjacent wiring board regions (see Patent Document 1).

  In recent years, wiring boards have become small, and for example, a board having a size of 1.6 × 1.2 mm in length and width is manufactured. In accordance with the miniaturization of the wiring board, the wiring board area in the multi-piece wiring board has also been reduced. In such a multi-piece wiring board in which wiring board areas that are remarkably reduced in size are arranged, due to restrictions on processing accuracy, etc., it is divided using a cutter blade at the boundary between adjacent wiring board areas in an unfired state. It is difficult to provide a groove. In view of this, a method has been proposed in which dividing grooves are formed by laser processing with excellent processing accuracy at the boundary between adjacent wiring board regions in a mother substrate before baking or after baking (see Patent Document 2).

Japanese Unexamined Patent Publication No. 2005-50935 JP 2005-109301 A

However, there is a possibility that the following problems occur in the above-described prior art multi-piece wiring board. That is, while the size of the wiring board is further reduced, the notch portion formed to enable positioning and electrical continuity cannot be reduced, so the size of one side of the wiring board is larger than the size of the notch portion. It is getting smaller. Therefore, the end of the dividing groove may be positioned on the inner surface of the notch. In this case, there is a possibility that an eluate such as a mother substrate or a chip of a cutter blade accompanying laser processing adheres to the inner surface of the notch portion to cause a protruding portion. When such a protruding portion is generated, there is a possibility that the positioning property (accuracy or ease of positioning, etc.) and electrical continuity of the multi-piece wiring board may be deteriorated. (Note that in laser processing, changing the laser forming speed and energy output is not preferable because it changes the depth and shape of the dividing grooves, which changes the splitting properties and individual shapes of the mother substrate. A large number of slabs were taken and passed through both ends of the wiring board to form dividing grooves.)

  In the multi-piece wiring board according to one aspect of the present invention, a first notch extending in the vertical direction is provided on a side surface of the mother board, and the first notch is formed on an upper surface of the mother board. A dividing groove extending in a direction along the outer side of the wiring board region is provided from a portion, and a part of a surface portion of the first notch portion of the mother board is partly in the plan view. A second notch having a diameter smaller than that of the notch is provided, and an end of the dividing groove is located in the second notch.

  According to the multi-cavity wiring board of one aspect of the present invention, the formation of the protruding portion on the inner surface of the first notch is suppressed when the dividing groove is formed on the mother board by a mold or laser processing. Therefore, positioning based on the first notch portion of the mother substrate and electrical continuity for plating and the like can be performed satisfactorily.

  In other words, even if burrs or eluents are generated at the end of the mother substrate when the dividing grooves are formed by a mold or a laser, the burrs or eluents are accommodated inside the second notch. For this reason, the formation of the protruding portion on the inner side surface of the first notch portion is suppressed, and the mother board can be positioned and electrically connected with reference to the inner side surface of the first notch portion. it can.

(A) is a top view which shows the multi-piece wiring board of embodiment of this invention, (b) is sectional drawing in the X-X 'line | wire of (a). It is a principal part enlarged top view which expands and shows the principal part of FIG. FIG. 5 is an enlarged view of a main part showing a first modification of the multi-cavity wiring board shown in FIGS. (A) is a principal part enlarged top view which shows the 2nd modification of the multi-piece wiring board shown to FIG. 1 and FIG. 2, (b) is sectional drawing in the YY 'line of (a). . FIG. 10 is an enlarged top perspective view of a main part showing a third modification of the multi-cavity wiring board shown in FIGS. 1 and 2.

  A multi-piece wiring board of the present invention will be described with reference to the accompanying drawings.

  FIG. 1A is a top view illustrating a multi-piece wiring board according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line X-X ′ in FIG. FIG. 2 is an enlarged top view of the main part of the multi-piece wiring board shown in FIG. FIG. 3 is an enlarged view of a main part showing a first modification of the multi-cavity wiring board shown in FIGS. 1 and 2. 4A is an enlarged top view of a main part showing a second modification of the multi-cavity wiring board shown in FIGS. 1 and 2, and FIG. 4B is a cross-sectional view taken along line YY ′ of FIG. FIG. FIG. 5 is an enlarged top perspective view of an essential part showing a third modification of the multi-cavity wiring board shown in FIGS. 1 and 2.

1 to 5, 101 is a mother board, 102 is a wiring board area, 103 is a wiring conductor, 104 is a margin area, 105 is a boundary, 106 is a dividing groove, 107 is a first notch 108 is a second notch. , 109 is an insulating layer, 110 is a metal layer, 111 is a mark, 112 is a mounting portion, 113 is a through hole, 114 is a protruding portion, 115 is a positioning pin, 116 is a connection conductor, 117 is a lead conductor, 118 Is the fracture region of the insulating layer.

For example, a plurality of wiring board regions 102 having mounting portions 112 are arranged vertically and horizontally on a mother board 101 in which a plurality of ceramic insulating layers 109 are laminated. On the top surface of the mother board 101,
A dividing groove 106 is formed in a direction along the outer side of the wiring board region 102, and a multi-piece wiring board is basically configured. The mother board 101 of the multi-piece wiring board is divided along the boundary 105 between the wiring board areas 102 or the boundary 105 between the wiring board area 102 and the disposal margin area 104, for example, a single wiring board (not shown). Is produced. The wiring board to be manufactured is an insulating substrate (101) in which an upper insulating layer (109) having a plurality of frame-like portions (openings) is laminated on the upper surface of a lower insulating layer (109) having a rectangular flat plate shape. ) Is basically configured by providing the wiring conductor 103, the through hole 113, and the like.

The mother substrate 101 is 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.

The plurality of wiring board regions 102 arranged on the mother board 101 have mounting parts 112 for electronic components (not shown) at the center or the like, and each is an area that becomes an individual wiring board. Each wiring board region 102 is formed by laminating a frame-like insulating layer (109) on an upper surface of a flat-like insulating layer (109). The frame-like insulating layer is for protecting electronic components mounted on the mounting portion 112.

The electronic parts mounted on the mounting unit 112 include various types of elements such as a piezoelectric vibrator such as a crystal vibrator, a surface acoustic wave element, a semiconductor element such as a semiconductor integrated circuit element (IC), a capacitive element, an inductor element, and a resistor. Mention electronic components.

In the example of this embodiment, as shown in FIG. 1, a margin area 104 is provided on the outer periphery of the mother board 101 which is a multi-piece wiring board so as to surround a plurality of wiring board areas 102 arranged. It has been. The disposal allowance area 104 is provided for facilitating handling of the multi-piece wiring board.

  The mother substrate 101 is manufactured by integrally firing a plurality of insulating layers 109. That is, a plurality of ceramic green sheets are prepared by adding a suitable organic solvent and binder to a raw material powder containing a ceramic component such as aluminum oxide and a glass component such as silicon oxide, and forming a plurality of ceramic green sheets. A part of the ceramic green sheet is punched and formed into a ceramic green sheet having a plurality of frame-shaped parts, and then the frame-shaped part is formed on a flat ceramic green sheet that is not punched. When the ceramic green sheets having the above structure are laminated and the laminated body is integrally fired, a mother substrate 101 in which a plurality of insulating layers 109 are laminated can be manufactured. A plurality of frame-shaped portions of the ceramic green sheet form a recess in each wiring board region 102.

  A wiring conductor 103 is formed on the inside and the surface of the mother board 101 from the mounting portion 112 to the lower surface of the mother board 101. A portion of the wiring conductor 103 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 103, those formed inside the mother board 101 are through conductors (so-called via conductors), internal wiring layers, connection conductors 116, and the like. By electrically connecting the electronic component mounted on the mounting portion 112 to the wiring conductor 103, the electronic component is electrically connected to an external electric circuit via the wiring conductor 103.

The wiring conductor 103 is, for example, copper, silver, palladium, gold, platinum, tungsten, molybdenum,
Made of a metal material such as manganese. For example, if the wiring conductor 103 is made of molybdenum, a metal paste (not shown) prepared by adding an organic solvent and a binder to molybdenum powder is applied to a ceramic green sheet serving as the base substrate 101 in a predetermined pattern. In addition, it can be formed by simultaneous firing.

  A wiring board produced by dividing such a multi-piece wiring board into individual pieces is, for example, an electronic device on which the above-described electronic components are mounted, and this electronic device is a communication device such as a mobile phone or a car phone. In electronic equipment such as equipment, computers, IC cards, and other information equipment, it is used as an oscillator that serves as a reference for frequency and time.

  Electronic components may be mounted on the wiring board region 102 before the plurality of wiring board regions 102 are divided into individual wiring boards, that is, in a multi-piece wiring board state. An electronic component is mounted on each mounting portion 112 of the plurality of wiring board regions 102 of the multi-cavity wiring board to produce a multi-cavity electronic device, which is divided into individual pieces to produce a large number of electronic devices. The

  The wiring conductor 103 and the like in the wiring board region 102 may be coated with a plating layer of nickel, gold, etc. to improve the reliability in mounting electronic components.

Further, in the outer peripheral portion of the mother board 101, a notch (for example, positioning for mounting electronic components on the wiring board region 102 or for electrical conduction such as plating with respect to the wiring board region 102) (
A first notch 107) is formed. When the notch (107) is for positioning the mother board 101 at a predetermined position when performing various processing on the mother board 101 or mounting electronic components, for example, the notch (107) is provided on each side. Two portions are provided so as to penetrate vertically and horizontally. The mother board 101 is positioned by preparing a jig (not shown) in which positioning pins 115 are erected at positions corresponding to the notches (107), and on the jig, the mother board 101 is placed. Is performed by placing the corresponding positioning pins 115 in the respective notches.

Further, when the notch (107) is intended for electrical conduction such as for plating with respect to the wiring board region 102, a metal electrically connected to the wiring board region 102 on the inner side surface thereof. A layer 110 is provided. A pin (not shown) of a jig for plating is in contact with the metal layer 110, and the metal layer 110
From this, a current for plating or the like is applied to each wiring board region.

In order to divide the mother board 101, dividing grooves 106 are formed on the upper and lower surfaces of the mother board 101 in the direction along the outer side of the wiring board region 102. The portion where the dividing groove 106 is formed (the boundary 105 between the wiring board regions 102, the boundary 105 between the wiring board region 102 and the discard margin region 104, and the boundary 105 between the wiring substrate regions 102 if necessary. By applying stress to the mother board 101 at a portion on the imaginary line extended to 104) and breaking the mother board 101 in the thickness direction, the mother board 101 is divided into individual wiring boards.

In the multi-cavity wiring board of the embodiment, a frame-shaped metal layer (not shown) may be formed on the upper surface of each wiring board region 102 in contact with the dividing groove 106. For example, the mounting portion 112 is sealed by bonding a lid to the frame-shaped metal layer. Further, a nickel plating layer and a gold plating layer may be sequentially deposited on the upper surface of the frame-shaped metal layer. The frame-like metal layer is made of a metal such as molybdenum, like the wiring conductor 103. The frame-like metal layer can be formed by the same method as the wiring conductor 103.

In addition, the plating layer such as nickel covering the wiring conductor 103 and the frame-shaped metal layer is formed to prevent oxidative corrosion of the frame-shaped metal layer, etc., and to improve wettability and bonding strength when brazing. It has been done. 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. Nickel plating layer is 2
The gold plating layer is formed to have a thickness of about 0.1 to 1.0 μm.

These plating layers can be formed by electrolytic plating as described above. Specifically, it can be formed by supplying a current in a plating solution to the wiring conductor 103 or the like in each wiring board region 102 and performing electrolytic plating. That is, a current sent from an external power source (plating power supply device such as a DC rectifier) is supplied to each connection conductor 116 via the metal layer 110 provided on the inner surface of the first notch 107. Further, it is supplied to the wiring conductor 103 and the like of each wiring board region 102 through a lead conductor 117 formed from the inner edge of the connection conductor 116 to the wiring board region 102.

  The dividing groove 106 is provided by a method such as mechanical processing in which a main surface of a ceramic green sheet (laminated body) serving as the mother substrate 101 is cut with a die or a cutter blade, or laser processing. .

When the dividing groove 106 is formed on the mother substrate 101 with a mold, a cutter blade or the like, for example, it is performed as follows. That is, on the upper surface of the ceramic green sheet laminate, a die (having blades formed in a lattice shape according to the arrangement of the wiring board regions) or a cutter blade in a direction along the outer edge of each wiring board region 102 The dividing groove 106 can be provided by making an extended cut and then firing the cut ceramic green sheet laminate at a high temperature.

Further, when the division grooves 106 are formed on the mother substrate 101 by laser processing, for example, the outer surface of each wiring substrate region 102 is formed on the upper surface of the ceramic green sheet laminate placed on a rectangular XY table by a laser processing apparatus. A dividing groove 106 extending in a direction along the side is formed. Thereafter, by firing the ceramic green sheet laminate formed with the dividing grooves 106 at a high temperature,
A dividing groove 106 can be provided. Here, the formation of the divided grooves 106 by laser processing may be performed after the ceramic green sheet laminate is fired at a high temperature.

In addition, a second cutout portion 108 having a smaller diameter than the first cutout portion 107 in plan view is provided on a part of the surface portion of the first cutout portion 107 in the mother substrate 101. The end portion of the dividing groove 106 is located in the two cutout portions 108. With such a structure, positioning based on the first notch 107 of the mother substrate 101 and electrical conduction for plating and the like can be performed satisfactorily.

That is, at the time of forming the dividing groove 106 by processing with a mold or laser processing, a part of the mother substrate 101 at the end of the dividing groove 106, or a protruding portion such as a burr that accompanies mold processing or an eluate during laser processing Even if 114 is generated, the protruding portion 114 is accommodated inside the second notch 108. Therefore, the formation of the protruding portion 114 beyond the inner side surface of the first notch 107 is suppressed. Thereby, for example, the positioning of the mother substrate 101 with respect to the inner side surface of the first cutout portion 107, electrical conduction, or the like can be performed satisfactorily.

The above effect will be described in more detail with an example. In recent years, wiring boards having dimensions of 1.6 × 1.2 mm in length and width have been manufactured. In accordance with the miniaturization of the wiring board, the wiring board area in the multi-piece wiring board has also been reduced. On the other hand, since a notch (not shown) for positioning or electrical conduction cannot be reduced, the length of one side of the wiring board is the size (length) of the notch in a direction parallel to the one side. ) Is getting smaller. In other words, the interval between the adjacent divided grooves 106 is getting smaller. Therefore, as shown in enlarged views of main parts in FIGS. 1 to 5, the number of cases where the end of the dividing groove 106 is located on the inner surface of the notch portion tends to increase. When the cutter blade is pushed into the ceramic green sheet laminate, a part of the ceramic green sheet is pushed out to the end of the mother substrate 101. The extruded portion remains as a burr after firing, and the possibility of such a failure is increasing.

On the other hand, in the multi-piece wiring board, even if a protruding portion 114 such as a burr is formed on the mother substrate 101 at the end portion of the dividing groove 106 having the second cutout portion 108, It fits inside the notch 108. Therefore, the formation of the protruding portion 114 on the inner surface of the first cutout portion 107 is suppressed. Therefore, for example, it is possible to satisfactorily perform positioning of the mother substrate 101 with respect to the inner surface of the first notch 107 or electrical conduction.

The same effect can be obtained when the dividing groove 106 is provided by laser processing.
When forming the dividing groove 106 extending in the direction along the outer side of each wiring board region 102 by the laser processing apparatus on the mother board 101 (or a laminate of ceramic green sheets to be the mother board 101), An eluate such as a material (ceramic such as aluminum oxide) or a metal material of the wiring conductor 103 is generated at the end of the dividing groove 106.

However, since the end portion of the dividing groove 106 is located in the second cutout portion 108, the eluate is stored inside the second cutout portion 108. Therefore, the eluate is prevented from protruding beyond the inner side surface of the first notch 107. Therefore, for example, the positioning of the mother substrate 101 with reference to the inner surface of the first notch 107, or a metal layer (described later) provided on the inner surface.
It is possible to satisfactorily perform electrical conduction for plating by bringing the pins of the plating jig into contact with each other. For the purpose of electrical conduction, a metallized layer is deposited on the inner surface of the first cutout 107. As a result, the pins of the plating jig and the inner surface of the first notch 107 and the metal layer 110 are electrically connected. This metallized layer has an action of relaxing stress at the time of contact with the positioning pins 115, and can suppress cracking of the mother substrate 101. Here, the second cutout portion 108 is for accommodating the protruding portion 114, and it is not necessary to deposit a metallized layer on the inner surface of the second cutout portion 108.

Note that the dividing groove 106 may be formed at the same position in plan view on both the front and back surfaces of the mother substrate 101 in order to improve the dividing property without generation of burrs and chips.

A plurality of second cutout portions 108 may be provided in one first cutout portion 107. In each of the plurality of second cutout portions 108, the end portion of the dividing groove 106 is located. In such a case, even when the wiring board becomes very small, positioning based on the first notch 107 of the mother board 101 and electrical conduction such as for plating can be performed satisfactorily. .

That is, as shown in FIG. 3, even when the length of one side of the wiring board is much smaller than the size (length) of the first notch 107 in the direction parallel to the one side, First
The end portions of the dividing grooves 106 are positioned in the plurality of second cutout portions 108 formed in the cutout portion 107.

  Further, the mother substrate 101 includes a plurality of insulating layers 109 stacked on each other, and the first cutout portion 107 and the second cutout portion 108 are any one of the plurality of insulating layers 109. It may be provided only. In such a case, even if stacking deviation occurs in the plurality of insulating layers 109 constituting the mother substrate 101, the other inner insulating layer 109 protrudes beyond the inner surface of the second notch 108. There is nothing.

  In other words, even if a misalignment occurs in another insulating layer 109 constituting the mother substrate 101, the first notch 107 is formed on any one of the insulating layers that protrudes most from the inner surface of the second notch 108. The second notch 108 is formed, and the mother board 101 can be positioned and electrically connected with the inner surface of the first notch 107 as a reference.

In this multi-piece wiring board, the notch portions (the first notch portion 107 and the second notch portion 108) are as shown in enlarged views of main parts in FIGS. 4 (a) and 4 (b). For example, in the uppermost insulating layer 109, the protruding width is about 0.2 to 0.5 mm larger than the protruding width in the other insulating layers 109. In this embodiment, the mother substrate 101 is composed of three insulating layers 109, and the first cutout portion 107 and the second cutout portion 108 are formed in the uppermost insulating layer 109. Show.

In the example of FIG. 4, the outer peripheral position of the second and third insulating layers 109 from the top is inward of the inner peripheral position of the first notch 107 provided in the uppermost insulating layer 109. It has become. In this case, in a plan view, the second and third insulating layers are provided with notches (not indicated) in a wider range than the first notch 107 provided in the uppermost insulating layer 109. It may be. Further, at least in the portion where the first cutout portion 107 is provided, the outer peripheral position of the second and third insulating layers 109 is more central in the mother substrate 101 than the outer peripheral position of the uppermost insulating layer 109. You may be on the side. Thereby, the above positioning and the like are easily performed without being obstructed by the second and third insulating layers 109. As shown in FIG. 4B, the protruding portion 114 such as a burr or eluate formed at the end of the dividing groove 106 has a maximum protruding width of about 0.5 mm, and the third insulating layer 109 (or the second to third insulating layers 109) has a protruding portion 114 on the lower surface side in the plan view of the outer peripheral position of the uppermost insulating layer 109 (that is, within the first notch 107). It does not protrude to the outer peripheral side of the mother board 101 from the peripheral position).

And the width | variety (dimension of the direction along the outer side of the mother board | substrate 101) of the 1st notch part 107 in the mother board | substrate 101 is about 3-8 mm, and depth (dimension of the direction orthogonal to a width | variety in planar view). Is about 2 to 12 mm. The size of the first notch 107 is appropriately determined according to the thickness and size of the mother board 101.

In this way, even if a stacking deviation of about 0.1 to 0.3 mm occurs between different insulating layers 109, the inner surface of the second notch 108 formed in any one insulating layer 109 The structure is such that it always protrudes from the inner surface of the notch portion formed in the other insulating layer 109 in the periphery thereof, regardless of the formation state of the protruding portion 114 such as burrs or eluate. Therefore, when the mother board 101 is placed on a jig or the like so that the positioning pins 115 corresponding to the first cutout portions 107 are inserted, accurate positioning and electrical conduction are possible. In this case, since the first notch 107 formed in the protruding insulating layer performs positioning of the mother substrate 101 or plating conduction, etc., the insulating layer 109 can be firmly held by the positioning pins 115. It is better to set the thickness. In the example of FIG. 4, the mother substrate 101 is composed of three insulating layers 109, and the uppermost insulating layer 109 is thicker than the other insulating layers 109.

The dividing groove 106 is formed on the upper and lower surfaces of the mother substrate 101. As shown in FIG. 4B, when the upper dividing groove 106 is formed, a protruding portion 114 is formed on the uppermost insulating layer 109. When the lower dividing groove 106 is formed, the protruding portion 114 is formed in the lowermost insulating layer 109. Further, in this example, since the cutter blade and the laser do not reach the intermediate insulating layer 109, a sectional view in a state where the dividing groove 106 is not formed (including a portion that becomes the fracture region 118) is shown. The burrs and eluents that become the protruding portions 114 tend to increase as the processing depth of the dividing grooves 106 into the insulating layer 109 that forms the dividing grooves 106 increases, and the maximum possibility that the protruding portions 114 may occur. In consideration of the protrusion amount, the size of the second notch 108, the protrusion width of the insulating layer 109 to be protruded from the other insulating layer 109, and the like may be determined.

If the mother substrate 101 is as thin as about 0.4 mm, for example, the dividing grooves 106 to be formed accordingly.
Reduce the depth appropriately. In such a case, when the cutter blade is pushed into the ceramic green sheet laminate to form the divided groove 106, a part of the ceramic green sheet is placed at the end of the laminate (mother substrate 101) because the divided groove 106 is shallow. Although the amount of the protruding portion due to the extrusion is reduced, a slight protruding portion 114 may be generated. Further, even when the dividing groove 106 is formed by the laser processing apparatus, although the amount of eluate such as the material of the base substrate 101 or the metal material of the wiring conductor 103 is reduced, the protruding portion 114 may also be generated. is there. However, with such a structure, even when the wiring board is very small, a plurality of dividing grooves 106 can be formed crossing the first notch 107 of the thin mother board 101, and the first Positioning based on one notch 107 and electrical continuity for plating and the like can be performed satisfactorily.

As a method of forming the second cutout portion 108, a plurality of ceramic green sheets to be the plurality of insulating layers 109 constituting the mother substrate 101 are prepared, and some of the ceramic green sheets among the plurality of ceramic green sheets are prepared. Frame-shaped part of the sheet (frame part surrounding mounting part 112)
At the same time, the first cutout portion 107 and the second cutout portion 108 are punched (ceramic green sheet A). Further, the first cutout portion 107 and the second cutout portion 108 are punched to prepare a flat ceramic green sheet in which the frame-shaped portion is not punched (ceramic green sheet B). . Thereafter, the ceramic green sheet A is laminated on the ceramic green sheet B, and if this laminate is integrally fired, a plurality of insulating layers 109 are laminated, and the first cutout portion 107 and the second cutout portion are laminated. The mother substrate 101 in which the notch 108 is formed can be manufactured. In addition, after punching out the second cutout portion 108 as necessary, the first cutout portion 107 may be punched separately.

Note that the first cutout 107 may be formed by dividing a through-hole (not shown) provided in the ceramic green sheet in a large area including a region to be the mother substrate 101 in the vertical direction. In this case, a through-hole (such as a circular shape in plan view) is provided across the outer periphery of the region to be the mother substrate 101 for the ceramic green (laminated body) having a large area. Thereafter, cutting is performed along the outer periphery of a region that becomes the mother substrate 101 in the ceramic green sheet having a large area. Thereby, the through-hole is divided in the vertical direction (thickness direction of the laminated body), and a laminated body of ceramic green sheets having, for example, a semicircular groove or the like (a portion that becomes the first cutout portion 107) in a plan view. Produced. If this laminate is fired, the mother substrate 101 having the first notch 107 can be manufactured.

Even if the mother board 101 is very thin as described above, for example, and the strength as a multi-piece wiring board is reduced, the first cutout portion 107 is formed to form the first cutout 107. It becomes possible to disperse the stress from the positioning pin 115 to the notch 107. Therefore, even when the thickness is reduced in this manner, positioning based on the first notch 107 of the mother substrate 101 and electrical conduction such as plating can be performed satisfactorily. Inadvertent cracking during handling can be suppressed.

Further, like the multi-cavity wiring board of the embodiment, the mother board 101 has a disposal margin area 104 on the outer periphery thereof, and the first cutout part 107 and the second cutout part 108 are A plurality of connection conductors 116 connecting the metal layer 110 attached to the first notch 107 and the wiring board region 102 are disposed in the discard margin area 104 while avoiding the dividing groove 106. It may be formed in the region 104. In such a case, the plating layer can be satisfactorily deposited on the exposed wiring conductor 103 of each small wiring board region 102 arranged on the mother board 101 even if the dividing groove 106 is formed.

That is, as shown in FIG. 5, a plurality of wiring board regions 102 (which are arranged from the metal layer 110 of the first cutout portion 107 to the mother board 101 and are smaller than the first cutout portion 107 in plan view) Even if a plurality of lead conductors 117 are formed over the outermost periphery), the plurality of lead conductors 117 are formed so as to avoid the dividing grooves 106, respectively. Therefore, each lead conductor 117 can be reliably electrically connected to the exposed wiring conductor 103 of each of a plurality of relatively small wiring board regions 102 arranged on the mother board 101 without being cut by the dividing groove 106. . As a result, the plating layer can be better applied to the wiring conductor 103.

A disposal allowance region 104 is formed on the outer peripheral portion of the mother board 101, and a lead conductor 117 is formed on this inner layer.
A frame-like connecting conductor 116 is formed which is wider than the above and surrounds the wiring board region 102. The connection conductor 116 is electrically connected to the metal layer 110 of the first notch 107 formed on the side surface of the mother board 101. For example, an inner conductor (not shown) formed between the metal layer 110 and the connection conductor 116 is divided into two parts so as to avoid the dividing groove 106 and connected to the connection conductor 116 as shown in FIG.

Further, in each of the above examples, the second cutout portion 108 formed in the surface portion in the first cutout portion 107 has a length direction that is an imaginary extension line (not shown) of the dividing groove 106. It is the direction along. Because of this form, even if the dividing groove 106 is formed slightly deviated from the boundary 105, the dividing groove 106 may be erroneously positioned at the outer peripheral end of the second notch 108. More effectively suppressed. That is, the protruding portion 114 generated at the end portion of the dividing groove 106 remains in the second cutout portion 108 more reliably. Therefore, it is more reliably suppressed that the protruding portion 114 due to burrs or eluate is formed on the inner surface of the first cutout portion 107.

FIG. 5 shows an example in which three second notches 108 are formed in one first notch 107, but depending on the number of second notches 108 to be formed, The number and shape of the connection conductors 116 may be appropriately changed. Further, the frame-shaped connection conductor 116 and each wiring board region 102 are electrically connected by a plurality of narrow lead conductors 117. A through hole 113 is formed at each corner of each wiring board region 102, and a metallized layer is deposited on the inner surface of the through hole 113 to form a through conductor (not shown). For example, the main surface of each wiring board region 102 is formed with a frame-shaped metal layer that serves as a sealing surface of the lid, and the wiring conductors 103 of each wiring board region 102 are connected to each other by the through conductor and the frame-shaped metal layer. Are electrically connected.

In such a lead conductor 117, the size of one side of the wiring board is reduced and the width is further reduced. However, since the dividing groove 106 is formed in the discard margin region 104 in this way, the lead conductor 117 can be separated from the vicinity of the dividing groove 106 when the dividing groove 106 is formed by a cutter blade or a laser. In addition, disconnection or deformation (a phenomenon in which the width is narrowed) of the lead conductor 117 due to stress or heat at the time of forming the dividing groove 106 can be suppressed. In addition,
The dividing groove 106 is formed using, for example, a mark 111 formed on the discard margin region 104 as a positioning index.

As a method of forming such a division groove 106, for example, the division groove 106 is formed by irradiating a laser in a direction along the outer side of the wiring board region 102 where the division groove 106 is formed. Then, the output is adjusted according to the processing accuracy such as the width and depth of the target dividing groove 106. The thickness of the frame-like metal layer (not shown) on the surface of each wiring board region 102 after firing is about 8 to 20 μm, the nickel plating layer is about 2 to 10 μm, and the gold plating layer is about 0.1 to 1.0 μm. The total thickness from the gold plating layer to the frame-like metal layer is about 10 to 30 μm. A split groove 106 having a depth of about 30 to 80 μm is formed on the mother substrate 101 including the frame-shaped metal layer, nickel plating layer, and gold plating layer. As the type of laser, for example, a YAG laser or a carbon dioxide laser can be used.

Note that the multi-piece wiring board of the present invention is not limited to the above embodiments, and various modifications may be made without departing from the gist of the present invention. For example,
Although the mother substrate 101 is a multi-cavity wiring substrate made of two to three insulating layers, it may be a multi-cavity wiring substrate having other number of layers. In addition, the wiring board region 102 arranged and formed on the mother board 101 is the wiring board area 102 having a shape in which the mounting portion 112 is a recess, but the mounting portion 112 has a plurality of flat plate-like wiring board regions 102 arranged. A wiring board may be used. Furthermore, although the shape of the notch is semicircular, it may be semielliptical, oblong, or V-shaped as necessary.

101 ... Mother board
102 ・ ・ ・ Wiring board area
103 ... Wiring conductor
104 ... Disposal area
105 ... Boundary
106 ・ ・ ・ Dividing groove
107 ... 1st notch
108 ... 2nd notch
109 ・ ・ ・ Insulating layer
110 ... Metal layer
111 ... mark
112 ・ ・ ・ Mounting part
113 ・ ・ ・ Through hole
114 ・ ・ ・ Projecting part
115 ... Positioning pin
116 ・ ・ ・ Connection conductor
117 ・ ・ ・ Drawer conductor
118 ・ ・ ・ Break area

Claims (4)

It has a mother board on which a plurality of wiring board areas are arranged,
On the side surface of the mother substrate is provided with a first notch extending in the vertical direction,
A dividing groove extending in a direction along the outer side of the wiring board region from the first cutout portion is provided on the upper surface of the mother board.
A second cutout portion having a smaller diameter than the first cutout portion in a plan view is provided on a part of the surface portion of the first cutout portion of the mother substrate. The multi-piece wiring board, wherein an end of the dividing groove is located in the notch. The mother substrate includes a plurality of insulating layers stacked on each other, and the first cutout portion and the second cutout portion are provided only on any one of the plurality of insulating layers. The multi-piece wiring board according to claim 1, wherein the wiring board is a multi-piece wiring board. 3. The multi-piece wiring board according to claim 1, wherein a plurality of the second cutout portions are provided in one of the first cutout portions. 4. A metal layer provided on a surface of the mother substrate in the first cutout,
A plurality of connecting conductors provided from the metal layer to the wiring board region located at least on the outermost periphery of the plurality of wiring board regions;
The mother board has a margin area on the outer periphery thereof;
The first cutout portion and the second cutout portion are located in the discard margin region, and the connection conductor is formed in the discard margin region while avoiding the dividing groove. The multi-piece wiring board according to any one of claims 1 to 3.