JP2006041310A - Multi-pattern wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-pattern wiring board improving dividing properties while inhibiting the peeling of a metallized layer in the case of a division. <P>SOLUTION: The multi-pattern wiring board has a mother board 101 in which a plurality of wiring-board regions 102 are arrayed and formed crosswise, and dividing trenches 103 formed to the mutual boundaries 109 of the wiring-board regions 102 of the top face 111 or underside 112 of the mother board 101. The multi-pattern wiring board further has through-holes 104 formed at sites where the boundaries 109 are crossed mutually, and the metallized layers 105 coated on the internal surfaces of the through-holes 104. The metallized layers 105 are coated so that regions containing the boundaries 109 of the internal surfaces of the through-holes 104 are exposed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multi-piece wiring board in which a plurality of wiring board regions are arranged in the center of a mother board in the vertical and horizontal directions.

  A wiring board on which electronic components such as semiconductor elements and crystal units are mounted is made of a ceramic material such as an aluminum oxide sintered body and is laminated with a plurality of square-plate-shaped ceramic insulation layers with wiring conductors formed on the surface. Made up. An electronic component is mounted on the wiring board, and an electrode of the electronic component is electrically connected to the wiring conductor via solder, a bonding wire or the like to form an electronic device.

  Here, with the recent miniaturization of electronic devices, the size of this wiring board has become extremely small, about several millimeters square, and the wiring board has been made easier to handle, and the manufacturing efficiency of the wiring board has been increased. In order to improve the manufacturing efficiency of the electronic device, it is manufactured in the form of a multi-piece wiring board in which a large number of wiring boards are obtained simultaneously from a large area mother board.

  This multi-cavity wiring board includes a plurality of wiring board regions arranged vertically and horizontally and a mother board in which a frame-like discard margin area is formed on the outer periphery, and wiring board regions on the upper surface or the lower surface of the mother substrate. A dividing groove formed at the boundary and a through-hole formed at a portion where the boundaries cross each other are provided.

  Then, the electronic component is mounted on the mounting portion of the wiring board region, and the electrodes of the electronic component are electrically connected to the wiring conductor via an electrical connection means such as a bonding wire or solder, and the mounting portion is formed on the upper surface of the wiring substrate region. By joining lids made of metal, glass, or the like so as to close the space, the electronic components are hermetically sealed inside the mounting portion, so that a large number of electronic devices are arranged vertically and horizontally. Thereafter, the electronic device in the multi-cavity state is divided into individual wiring board regions, thereby forming a plurality of electronic devices. In some cases, electronic components are mounted on the wiring board area after the multi-piece wiring board is divided into individual wiring board areas.

  Here, a metallized layer is formed on the inner surface of the through hole, and each wiring conductor in the adjacent wiring board region is conducted through the metallized layer. As a result, the wiring conductors of the plurality of wiring board regions are electrically connected to each other and a plating current is supplied collectively. Further, the metallized layer formed in the through hole has a function of conducting the wiring conductor managed on the upper and lower surfaces of the substrate.

Further, the division grooves are formed at the boundaries between the wiring board regions in order to separate the plurality of wiring board regions. For this reason, the through-hole is formed so as to cross the dividing groove. The dividing grooves are formed, for example, by pressing a metal blade, a metal mold, or the like against the upper surface or the lower surface of the laminate of ceramic green sheets serving as a mother substrate. The division of the mother board using the dividing grooves is performed by applying a bending stress to the mother board along the dividing grooves, causing a crack from the dividing groove of the mother board to the surface facing the mother board, and breaking the mother board. . The following documents disclose such conventional multi-piece wiring boards.
JP 2003-249593 A

  However, in the conventional multi-cavity wiring board, since the metallized layer is attached to the inner surface of the through hole, the metallized layer hinders the division when the mother board is broken and divided along the dividing groove. There is a problem that burrs or chips may occur on the divided wiring board (divided wiring board).

  In particular, with the recent miniaturization of electronic devices, miniaturization of wiring boards has progressed, and wiring boards have become extremely small, for example, the length of one side is 3 mm or less. When the wiring board is reduced in size in this way, the inner dimension of the through hole formed at the boundary between the wiring board regions is reduced accordingly, compared to the metallized layer attached to the inner surface of the large through hole, The plating layer deposited on the surface has become relatively thick. When the mother board is divided along the dividing grooves, the thick plating layer hinders the occurrence of problems such as burrs and chips on the wiring board.

  In addition, since the inner dimension of the through hole is reduced, the joint area between the metallized layer and the through hole is also reduced, and the metallized layer may be peeled off from the inner surface of the through hole due to a crack at the time of division. In particular, there is a high possibility that the metallized layer is peeled off at the terminal end side of the crack of the mother substrate (the side opposite to the dividing groove).

  The present invention has been devised in view of such problems, and an object of the present invention is to provide a multi-piece wiring board that improves the splitting property and suppresses peeling of the metallized layer at the time of splitting.

  The multi-cavity wiring board according to the present invention includes a mother board in which a plurality of wiring board regions are arranged vertically and horizontally, a dividing groove formed at a boundary between the wiring board regions on the upper surface or the lower surface of the mother board, A through hole formed at a portion where the boundary intersects, and a metallized layer attached to the inner surface of the through hole, the metallized layer exposing a region including the boundary of the inner surface of the through hole It is characterized by being attached as described.

  In the multi-piece wiring board of the present invention, preferably, the metallized layer is attached so that a region including the bottom of the dividing groove on the inner surface of the through hole is exposed. To do.

  In the multi-piece wiring board of the present invention, preferably, the metallized layer is covered so that a region including the end portion on the lower surface side or the end portion on the upper surface side of the inner surface of the through hole is exposed. It is characterized by being worn.

  Moreover, the multi-piece wiring board of the present invention is preferably characterized in that the metallized layer is applied over the entire circumference of the inner surface of the through hole.

  In the multi-cavity wiring board of the present invention, the metallization layer is applied so that the region including the boundary of the inner surface of the through hole is exposed, so that the metallization layer is formed in the region including the boundary of the inner surface of the through hole. The strength can be reduced, the hindrance to the division of the mother substrate by the metallized layer can be suppressed, and the division property can be improved. Further, by improving the partitionability, it is possible to suppress the occurrence of burrs and chips on the wiring board.

  Further, according to the multi-cavity wiring board of the present invention, preferably, the metallization layer is attached so that the region including the bottom of the dividing groove on the inner surface of the through hole is exposed, so that the dividing groove is formed. When making a crack from the side where it is formed, the external force applied to make the crack can be made small, and the splitting property can be further improved. Further, by improving the partitionability, it is possible to suppress the occurrence of burrs and chips on the wiring board.

  Further, according to the multi-cavity wiring board of the present invention, preferably, the metallized layer is attached so that the lower surface side end portion or the region including the upper surface side end portion of the inner surface of the through hole is exposed. As a result, the strength of the end on the lower surface side or the end on the upper surface side of the inner surface of the through hole can be reduced, and hindering the division of the mother substrate by the metallized layer can be suppressed and the dividing property can be improved. Further, by improving the partitionability, it is possible to suppress the occurrence of burrs and chips on the wiring board.

  Further, the metallized layer is applied so that the region including the end portion on the lower surface side or the upper surface side of the inner surface of the through hole is exposed, so that the end portion on the lower surface side of the inner surface of the through hole or It is possible to suppress peeling of the metallized layer that occurs from the end portion on the upper surface side (that is, the end portion on the side opposite to the surface on which the dividing grooves are formed).

  Further, according to the multi-cavity wiring board of the present invention, preferably, the metallization layer is applied over the entire circumference of the inner surface of the through hole, so that in the wiring board region arranged vertically and horizontally on the mother board. The wiring conductors in the adjacent wiring board regions can be electrically connected to each other through the metallized layer formed on the inner surface of the through hole, and the plating process of the wiring conductors formed in each wiring board region can be efficiently performed. It can be carried out.

  The multi-piece wiring board of the present invention will be described in detail with reference to the drawings. First, a first example of an embodiment of a multi-piece wiring board according to the present invention will be described with reference to FIG. Fig.1 (a) is a top view which shows the structure of the 1st example of the multi-piece wiring board of this invention. FIG. 1B is a cross-sectional view taken along line X-X ′ of the multi-piece wiring board shown in FIG. FIG. 1C is a cross-sectional view taken along line Y-Y ′ of the multi-piece wiring board shown in FIG.

  The multi-cavity wiring board according to the present invention is formed in a portion where the boundary intersects with the mother board 101 in which a plurality of wiring board regions 102 are arranged vertically and horizontally, and the divided grooves 103 formed on the upper surface or the lower surface of the mother board. And a metallized layer 105 deposited on the inner surface of the through-hole 104.

  The mother substrate 101 is made of a ceramic material such as an aluminum oxide sintered body (ceramics), an aluminum nitride sintered body, a mullite sintered body, or a glass ceramic, and is formed by laminating a plurality of insulating layers. In the mother board 101, a plurality of wiring board regions 102 are arranged in a central portion in a rectangular shape as a whole vertically and horizontally.

  If the mother substrate 101 is made of, for example, an aluminum oxide sintered body, a plurality of ceramic green sheets (hereinafter referred to as green sheets) in which raw material powders such as aluminum oxide are formed into a sheet shape are prepared and vertically and horizontally. A wiring board region 102 and a disposal margin region 106 are provided by partitioning, and then the green sheet is punched and then laminated and fired.

  The wiring board region 102 has, for example, a rectangular shape having a side length of about 2.0 to 20.0 mm and a thickness of about 0.4 to 2.0 mm. In the central portion of the upper surface 111 of each wiring board region 2, a mounting portion 107 including a recess for storing and mounting an electronic component is provided. A wiring conductor 108 is formed in each wiring board region 102.

  The wiring conductor 108 is electrically connected to an electrode of an electronic component mounted on the mounting portion 107 via a bonding wire, solder, or the like, and functions as a conductive path led out to the side surface or the lower surface of the wiring board region 102. The wiring conductor 108 is made of a metal material such as tungsten, molybdenum, copper, or silver. If the wiring conductor 108 is made of, for example, tungsten, the wiring conductor 108 is formed by printing a metal paste of tungsten in a predetermined pattern on a green sheet serving as the mother substrate 101 and simultaneously firing the green sheet.

  In order to suppress the oxidative corrosion and improve the characteristics such as the wettability of the solder when connecting the solder or the bonding wire, the bonding wire connectivity, etc. on the surface of the wiring conductor 108 (see FIG. (Not shown) is attached. In order to plate the wiring conductor 108, a multi-piece wiring board is immersed in a plating solution such as nickel or gold, and a predetermined plating current is supplied to the wiring conductor 108. A plating conduction pattern 110 is formed on a pair of opposing sides of the mother board 101 so as to be electrically connected to the wiring conductor 108. A conduction terminal (rack) provided on a plating jig (rack) is provided. (Not shown) is brought into contact with the plating conduction pattern 110, and the plating conduction pattern 110 is sandwiched from above and below by a pair of ends of the conduction terminal, whereby the conduction terminal and the plating conduction pattern 110 are connected from the power source. Thus, a plating current is supplied to the wiring conductor 108.

  The discard margin area 106 is formed in a frame shape on the outer peripheral portion of the mother board 101. The disposal allowance area 106 facilitates the handling of the multi-piece wiring board and facilitates the formation of the plating layer when the plating layer is applied to the wiring conductor 108 as described above, and is uniform and stable. It is formed for things.

  The dividing groove 103 is formed at the boundary 109 between the wiring board regions 102. In the multi-piece wiring board of the first example of the present invention shown in FIG. 1, the dividing groove 103 is formed on the upper surface 111 of the mother board 101. The dividing groove 103 is formed to improve the dividing efficiency in the step of dividing the mother board 101 into the respective wiring board regions 102. By bending the mother substrate 101 around the dividing groove 103, the mother substrate 101 is broken and divided from the bottom of the dividing groove 103 to the opposing surface (the lower surface 112 in the example of FIG. 1). The dividing grooves 103 may be formed on both upper and lower surfaces of the mother substrate 101. Further, it is desirable that the dividing groove 103 is also formed at a boundary 109 between the wiring board region 102 and the disposal margin region 106. The dividing groove 103 is formed by, for example, pressing a metal blade or a metal mold or the like into the boundary of the wiring board region 102 on the upper surface of the green sheet laminate to be the mother board 101 to make a cut at a predetermined depth. The

  The metallized layer 105 is deposited so that the region including the boundary 109 on the inner surface of the through hole 104 is exposed. That is, in the multi-piece wiring board of the first example of the present invention shown in FIG. 1, the metallized layer 105 is not formed on the inner surface of the through-hole 104 in the area overlapping the boundary line between the wiring board areas 102 in the vertical direction. Region 114 is provided. With this configuration, the strength of the metallized layer 105 deposited on the inner surface of the through hole 104 is reduced at the boundary 109 when the wiring board is divided along the dividing groove 109 formed at the boundary 109 between the wiring substrate regions 102. Thus, the division of the wiring board can be improved. Further, by improving the partitionability, it is possible to suppress the occurrence of burrs and chips on the wiring board.

  Further, in the multi-piece wiring board of the present invention, the metallized layer 105 may be attached so that a region including an end portion on the lower surface side or an end portion on the upper surface side of the inner surface of the through hole 104 is exposed. preferable. In the multi-piece wiring board of the first example of the present invention shown in FIG. 1, the metallized layer 105 is deposited so that the region including the end portion on the lower surface 112 side of the inner surface of the through hole 104 is exposed. Yes. That is, the non-formation region 114 of the metallized layer 105 is provided in a region including the end of the inner surface of the through hole 104 on the lower surface 112 side. With such a configuration, the multi-cavity wiring board of the present invention can reduce the strength of the lower surface end or the upper surface end of the inner surface of the through hole, and hinder the division of the mother substrate by the metallized layer. Can be suppressed and the splitting property can be improved. Further, by improving the partitionability, it is possible to suppress the occurrence of burrs and chips on the wiring board. Further, the metallized layer is applied so that the region including the end portion on the lower surface side or the upper surface side of the inner surface of the through hole is exposed, so that the end portion on the lower surface side of the inner surface of the through hole or It is possible to suppress peeling of the metallized layer that occurs from the end portion on the upper surface side (that is, the end portion on the side opposite to the surface on which the dividing grooves are formed).

  Further, in the multi-piece wiring board of the present invention, the metallized layer 105 is preferably applied over the entire inner surface of the through hole 104. In the multiple wiring substrate of the first example of the present invention shown in FIG. 1, the metallized layer 105 is deposited over the entire inner surface of the through hole 104 in the first region 113. With this configuration, the multi-piece wiring board of the present invention has a metallized layer in which wiring conductors of adjacent wiring board areas are formed on the inner surface of the through hole in the wiring board area arranged vertically and horizontally on the mother board. The wiring conductor formed in each wiring board region can be efficiently plated.

  An electronic component (not shown) is mounted on the mounting portion 107 of the wiring board region 102, and the electrodes of the electronic component are exposed to the mounting portion 102 or its periphery via an electrical connection means such as a bonding wire or solder. The wiring conductor 108 is electrically connected. A lid made of metal, glass, or the like is bonded to the upper surface 111 of the wiring board region 102 so as to close the mounting portion 107. Alternatively, the mounting portion 107 is filled with a resin filler made of epoxy resin or the like. In this way, by electronically sealing the electronic components inside the mounting portion 107, a large number of electronic devices are formed in a multi-cavity state arranged and formed vertically and horizontally. Then, the electronic device in a multi-piece state is divided for each wiring board region 102, thereby forming an electronic device as a large number of products. The mounting of electronic components on the wiring board region 102 may be performed after the multi-piece wiring board is divided into individual wiring board regions 102.

  Next, a second example of the embodiment of the multi-piece wiring board according to the present invention will be described with reference to FIG. FIG. 2A is a plan view showing a structure of a second example of the multi-piece wiring board of the present invention. FIG. 2B is a cross-sectional view taken along the line X-X ′ of the multi-piece wiring board shown in FIG. FIG. 2C is a cross-sectional view taken along line Y-Y ′ of the multi-piece wiring substrate shown in FIG. In the multi-chip wiring board of the present invention, the divided grooves 103 and 203 are formed on the upper surface 111 and the lower surface 112 of the mother substrate 101.

  The metallized layer 205 is attached so that a region including the boundary 109 on the inner surface of the through hole 104 is exposed. That is, in the multi-piece wiring board of the second example of the present invention shown in FIG. 2, the metallized layer 205 is not formed in the inner surface of the through hole 104 in the region overlapping with the boundary line between the wiring substrate regions 102 in the vertical direction. Region 214 is provided. With such a configuration, when the wiring board is divided along the dividing groove 109 formed at the boundary 109 between the wiring board regions 102, the strength of the metallized layer 105 deposited on the inner surface of the through hole 104 is changed to the boundary 109. In this case, the division of the wiring board can be improved. Further, by improving the partitionability, it is possible to suppress the occurrence of burrs and chips on the wiring board.

  Further, in the multi-piece wiring board of the present invention, the metallized layer 105 is preferably applied over the entire inner surface of the through hole 104. In the multiple wiring substrate of the second example of the present invention shown in FIG. 2, the metallized layer 205 is deposited over the entire inner surface of the through hole 104 in the second region 213. With this configuration, the multi-piece wiring board of the present invention has a metallized layer in which wiring conductors of adjacent wiring board areas are formed on the inner surface of the through hole in the wiring board area arranged vertically and horizontally on the mother board. The wiring conductor formed in each wiring board region can be efficiently plated.

  In the multi-piece wiring board of the present invention, it is preferable that the metallized layer 105 is attached so that a region including the bottom of the dividing groove on the inner surface of the through hole is exposed. In the multi-piece wiring board of the second example of the present invention shown in FIG. 2, the metallized layer 205 is attached so that the region including the bottom of the dividing groove 203 on the inner surface of the through hole 104 is exposed. . That is, in the multi-piece wiring board of the second example of the present invention shown in FIG. 2, the non-formation region 214 of the metallized layer 205 is formed in the region including the bottom of the dividing groove 203 on the inner surface of the through hole 104. . With such a configuration, the multi-cavity wiring board according to the present invention can reduce the external force applied to make a crack when making a crack from the side where the dividing groove is formed, thereby reducing the dividing property. Further improvement is possible. Further, by improving the partitionability, it is possible to suppress the occurrence of burrs and chips on the wiring board.

  In the example shown in FIGS. 1 and 2, the through hole 104 is formed at the corner of the wiring board region 102, but not only at the corner of the wiring board region 102 but also at each side of the wiring board region 102. It may be formed.

(A) is a top view which shows the structure of the 1st example of the multi-cavity wiring board of this invention, (b) is in the XX 'line | wire of the multi-cavity wiring board shown to (a). It is sectional drawing, (c) is sectional drawing in the YY 'line of the multi-cavity wiring board shown to (b). (A) is a top view which shows the structure of the 2nd example of the multi-cavity wiring board of this invention, (b) is in XX 'line | wire of the multi-cavity wiring board shown to (a). It is sectional drawing, (c) is sectional drawing in the YY 'line of the multi-cavity wiring board shown to (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Mother board | substrate 102 ... Wiring board area | region 103 ... Dividing groove 104 ... Through-hole 105 ... Metallization layer 106 ... Discard allowance area 107 ... Mounting part 108 ... Wiring conductor 109 ... boundary 110 ... plating conduction pattern 111 ... upper surface 112 ... lower surface 113 ... first region 114 ... non-formation region

Claims (4)

A plurality of wiring board regions arranged vertically and horizontally, a dividing groove formed at the boundary between the wiring board regions on the upper surface or the lower surface of the mother substrate, and a penetration formed at a portion where the boundaries intersect A hole and a metallized layer deposited on the inner surface of the through-hole, and the metallized layer is deposited so that the region including the boundary of the inner surface of the through-hole is exposed. A multi-piece wiring board characterized by 2. The multi-piece wiring board according to claim 1, wherein the metallized layer is attached so that a region including a bottom portion of the division groove on the inner surface of the through hole is exposed. The metallized layer is attached so that a region including an end portion on the lower surface side or an end portion on the upper surface side of the inner surface of the through hole is exposed. 2. The multi-piece wiring board according to 2 The multi-piece wiring board according to any one of claims 1 to 3, wherein the metallized layer is applied over the entire circumference of the inner surface of the through hole.

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