JP4557786B2 - Multiple wiring board - Google Patents

Description

  The present invention relates to a multi-cavity wiring board in which a plurality of wiring board regions on which electronic components such as semiconductor elements and crystal resonators are mounted are arranged vertically and horizontally.

  2. Description of the Related Art Conventionally, for example, a wiring board used in an electronic component storage package in which electronic components such as semiconductor elements and crystal resonators are stored is made of a ceramic material such as an aluminum oxide sintered body. This wiring board has a structure in which a plurality of ceramic insulating layers having wiring conductors formed on the surface thereof are laminated. An electronic component is accommodated in a concave portion on the upper surface of 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 constitute an electronic device.

  By the way, with the recent miniaturization of electronic devices, such a wiring board has become extremely small with a size of several millimeters square, and the thickness thereof is very small, for example, 0.5 mm or less. It is getting thinner. Such a small number of wiring boards are easy to handle, and in order to improve the production efficiency of the wiring board and the electronic device, a large number of wiring boards from one mother board made of a ceramic material or the like. Are produced in the form of a multi-piece wiring board that can be obtained simultaneously and collectively.

  An example of such a multi-piece wiring board is shown in FIG. The multi-cavity wiring board includes a mother board 201 in which a plurality of wiring board areas 202 are arranged in rows and columns, a plurality of wiring conductors 209 formed in each wiring board area 202, and a frame formed on the outer periphery of the mother board 201. It is a structure provided with a shape disposal area 203.

  The upper surface of each wiring board region 202 is formed with a recess 205 in which an electronic component is mounted. A part of the wiring conductor 209 is exposed to the upper surface of the wiring board region 202 or its periphery, A part of the wiring board region 202 is formed so as to be exposed on the lower surface and side surfaces.

  Then, an electronic component (not shown) is mounted in the recess 205 of the wiring board region 202, and an electrode of the electronic component is electrically connected to the wiring conductor 209 via an electrical connection means such as a bonding wire or solder. . Then, a lid made of metal, glass, or the like is bonded to the upper surface of the wiring board region 202 so as to close the recess 205, or the electronic component is covered with a resin sealing material made of epoxy resin, etc. An electronic component is housed in the airtight inside 205. In this way, a large number of electronic devices are formed in a multi-piece state in which the horizontal and vertical arrangements are arranged.

A plurality of electronic devices are formed by dividing the electronic device in a multi-cavity state into individual wiring board regions 202. In some cases, the electronic component is mounted on the wiring board area 202 after the multi-piece wiring board is divided into the individual wiring board areas 202.
JP 2000-340898 A

  However, with the recent reduction in height of electronic devices, wiring boards used as electronic component storage packages are also required to be made thinner, and the entire mother board 201 has been made thinner. When the mother board 201 is thus thinned, due to the difference in shrinkage ratio during firing between the ceramic green sheet to be the mother board 201 and the metal paste formed on the surface thereof (the surface of each wiring board region 202), At the boundary between the wiring board region 202 and the disposal margin region 203, a large stress is generated over the entire length of each side of the mother board 201, and the mother board 201 may be warped in a concave shape or a convex shape.

  That is, for example, if the wiring board region 202 has a metallized layer formed on the surface and the discarding region 203 having no metallized layer formed on the surface, the wiring substrate region 202 is more preferable than the discarding region 203. Shrinkage is reduced. Then, the mother substrate 201 may be warped due to stress generated in the mother substrate 201 due to the difference in shrinkage rate.

  When the mother board 201 is warped, when dividing the mother board 201 into each wiring board area 202, the boundary between the wiring board area 202 and the disposal margin area 203 may be distorted. When the metal frame is positioned on the upper surface of the wiring board region 202 or when an electronic component is mounted on each wiring board region 202, the positional accuracy may be lowered.

  In addition, when the mother board 201 is warped, a predetermined force cannot be applied to the mother board 201 by the dividing device when the mother board 201 is divided into each wiring board area 202, and each wiring board area 202 is also not able to be applied. The stress necessary to divide the substrate may be dispersed in other parts, causing inadvertent cracks in the mother board 201, and cracks or chips in parts other than the split grooves. It was.

  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 in which warpage is reduced even when the thickness is reduced.

In the multi-cavity wiring board of the present invention, a plurality of wiring board regions are arranged vertically and horizontally in the central portion, and a discarding region is formed in the outer peripheral portion, and the wiring is provided in the discarding region. and a periphery metallized layer formed to surround the substrate region, the outermost periphery of the array of the wiring board region, dummy region having the same shape and outer dimensions as the wiring substrate region, alternately with the wiring substrate region The wiring board region is formed with a wiring conductor, and the dummy region is not formed with the wiring conductor .

  The multi-cavity wiring board of the present invention is formed such that dummy areas having the same shape and outer dimensions as the wiring board area are alternately arranged with the wiring board area on the outermost periphery of the wiring board area arrangement. As a result, it is possible to reduce the difference in shrinkage rate during firing between the outermost peripheral region and the disposal margin region of the wiring substrate region arrangement, and it is possible to reduce the stress generated in the mother substrate. In addition, the possibility that the mother substrate warps in a concave shape or a convex shape can be reduced.

  Further, by reducing the possibility that the mother board is warped, it is possible to improve positional accuracy such as mounting of electronic components. In addition, since the possibility of warping the mother board is reduced, the possibility of inadvertent cracking or the like when the mother board is divided into wiring board regions can be reduced.

  In addition, the multi-cavity wiring board of the present invention has the same shrinkage ratio during firing of the dummy area and the discard margin area because the material and thickness of the dummy area are the same as the material and thickness of the discard margin area. In addition, it is possible to further reduce the difference in shrinkage rate during firing between the outermost peripheral region of the wiring board region array and the disposal margin region, and to prevent the mother substrate from warping in a concave shape or a convex shape. it can.

  Further, the multi-cavity wiring board according to the present invention has a dummy recess having the same shape and dimensions as the recess formed in the wiring board region in the dummy area. Since the surface area including the inner surface of the substrate becomes equal, the influence of heat received from the firing furnace can be made substantially equal, and the difference in shrinkage rate during firing between the wiring board region and the dummy region can be reduced. And the difference of the shrinkage | contraction rate at the time of baking of a wiring board area | region, a dummy area | region, and a disposal margin area | region can be reduced, and possibility that a mother board will warp in a concave shape or convex shape can further be reduced.

  Next, the multi-piece wiring board of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1A is a plan view showing an example of an embodiment of a multi-cavity wiring board according to the present invention, and FIG. 1B is an A view of the multi-cavity wiring board shown in FIG. It is sectional drawing in the -A 'line.

  The multi-cavity wiring board of the present invention includes a mother board 101 on which a plurality of wiring board areas 102 and discard margin areas 103 are formed, and an outer peripheral metallized layer 104 formed so as to surround the wiring board area 102. . In the multi-piece wiring board of the present invention, dummy areas 110 having the same shape and outer dimensions as the wiring board area 102 are alternately arranged with the wiring board area 102 at the outermost periphery of the arrangement of the wiring board areas 102. It is formed as follows.

  The mother substrate 101 is formed by laminating ceramic layers such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, and glass ceramics. In the central portion of the mother board 101, a plurality of wiring board regions 102, each of which serves as a wiring board for mounting electronic components, are arranged vertically and horizontally. A recess 105 is provided in the center of the upper surface of each wiring board region 102 to accommodate and mount an electronic component (not shown).

  If such a base substrate 101 is made of, for example, an aluminum oxide sintered body, a plurality of green sheets obtained by forming a raw material powder such as aluminum oxide into a sheet shape are prepared, and the surface of the green sheet is vertically and horizontally oriented. A wiring board region 102 is provided in a divided manner, and then a part of the green sheet is subjected to an appropriate punching process, and then laminated and fired.

  Note that the electronic components mounted on the wiring board (wiring board region 102) are piezoelectric elements such as crystal resonators and surface acoustic wave filters, semiconductor elements, capacitors, resistors, and the like.

  A wiring conductor 109 is formed in each wiring board region 102. The wiring conductor 109 is electrically connected to the electrode of the electronic component housed in the recess 105 via a bonding wire, solder, or the like, and serves as a conductive path that leads to the lower surface or side surface of the wiring board region 102.

  The wiring conductor 109 is made of a metal material such as tungsten, molybdenum, copper, or silver. For example, if the wiring conductor 109 is made of tungsten, the wiring conductor 109 is formed by printing a metal paste of tungsten in a predetermined pattern on a green sheet serving as the mother substrate 101.

  On the surface of the wiring conductor 109, in order to prevent oxidative corrosion and to improve solder wettability when bonding solder and bonding wires, bonding wire bonding properties, etc., a plating layer (see FIG. (Not shown) is attached.

  This plating layer is formed by supplying a plating deposition current to the portion to be plated (the surface of the wiring conductor 109) in the plating solution and performing electrolytic plating.

  Further, the current is supplied through the outer peripheral metallized layer 104 formed so as to surround the wiring board region 102 inside the disposal margin region 103.

  That is, for example, a current is supplied from an external power source to the outer peripheral metallization layer 104 via the plating conduction terminals 108 formed on the two sides of the mother substrate 101, and the wiring conductor in the outermost peripheral wiring board region 102 is transmitted from the outer peripheral metallization layer 104. By supplying current to 109, current is sequentially supplied to each wiring board region 102 inside the array via the through conductor 106 formed between the wiring board regions 102.

  The outer peripheral metallized layer 104 and the plating conduction terminal 108 can be formed by the same method using the same metal material as the wiring conductor 109.

  In the multi-piece wiring board of the present invention, dummy areas 110 having the same shape and outer dimensions as the wiring board area 102 are alternately arranged with the wiring board area 102 on the outermost periphery of the arrangement of the wiring board areas 102. Is formed. In the example of the multi-piece wiring board shown in FIG. 1, no wiring conductor (metallized layer) is formed in the dummy region 110.

  The multi-wiring board of the present invention is formed such that dummy areas 110 having the same shape and outer dimensions as the wiring board area 102 are alternately arranged with the wiring board area 102 on the outermost periphery of the arrangement of the wiring board areas 102. By doing so, it is possible to reduce the difference in shrinkage rate at the time of firing between the outermost peripheral region of the arrangement of the wiring substrate regions 102 and the disposal margin region 103, and to reduce the stress generated in the mother substrate 101. It becomes. In addition, the possibility that the mother substrate 101 warps in a concave shape or a convex shape can be reduced.

  That is, in the multi-cavity wiring board of the present invention, the stress generated by the difference in shrinkage rate between the metal paste and the ceramic green sheet at the boundary between the wiring board region 102 and the disposal margin region 103 is caused by the mother board. It is possible to prevent the mother substrate 101 from warping in a concave shape or a convex shape by preventing it from acting continuously over the entire length of one side of the 101. And possibility that an inadvertent crack will arise in mother board 101 can be reduced.

  In addition, since the possibility that the mother board 101 is warped is reduced, the positional accuracy of mounting electronic components can be improved.

  In addition, since the possibility that the mother board 101 is warped is reduced, the possibility of inadvertent cracking or the like when the mother board 101 is divided into the wiring board regions 102 can be reduced.

  In addition, since the dummy region 110 has the same shape and outer dimensions as the wiring board region 102, the dividing groove can be formed under the same conditions in the outermost periphery and the central part of the arrangement of the wiring board region 102. The mother board 101 can be easily divided by the same dividing device as the mother board.

  In addition, since the dummy region 110 having the same shape and outer dimensions as the wiring substrate region 102 is formed, the dividing grooves are formed in the wiring substrate region 102 and the dummy region 110 under the same conditions (interval and depth). Therefore, when the mother board 101 is divided into the respective wiring board regions 102, it can be easily divided by the same dividing device as the conventional mother board 101.

  As long as the shape and outer dimensions of the dummy region 110 are the same as those of the wiring substrate region 102, a through-hole penetrating the mother substrate 101 in the thickness direction may be provided at the center of the dummy region. With such a configuration, the efficiency of the plating solution circulation can be improved during the festival of forming the plating layer.

  In addition, it is preferable that the dummy regions 110 are located at corners of the arrangement of the wiring substrate region 102 and the dummy region 110 (four corners of the mother substrate 101). With such a configuration, it is possible to reduce the possibility of warping particularly at the corners of the mother board 101 that are easily affected by the difference in shrinkage rate.

  In the multi-piece wiring board of the present invention, the material and thickness of the dummy region 110 are preferably the same as the material and thickness of the disposal margin region 103. With such a configuration, the multi-cavity wiring board of the present invention can reduce the difference in shrinkage rate during firing between the dummy region 110 and the disposal margin region 103, and the mother substrate 101 can be concave or convex. The possibility of being reduced can be further reduced.

  Further, the multi-piece wiring board of the present invention has a dummy structure by using the same green sheet and punching die as those used for manufacturing a conventional mother board and changing the printing screen. Regions can be formed.

  Further, in the multi-piece wiring board of the present invention, it is preferable that a dummy recess 111 having the same shape and size as the recess 105 formed in the wiring board region 102 is formed in the dummy region 110. With such a configuration, the multi-cavity wiring board of the present invention has the same surface area including the inner surface of the recess in the wiring board region 102 and the dummy region 110, and the effects of heat received from the firing furnace can be made substantially equal. In addition, it is possible to reduce the difference in shrinkage rate between the wiring board region 102 and the dummy region 110 during firing.

  In the multi-piece wiring board of the present invention, the mechanical strength (rigidity) of the wiring board region 102 and the dummy area 110 is equalized by such a configuration, and therefore the mother board 101 is divided into the wiring board areas 102. At this time, it is possible to reduce the possibility of inadvertent cracking of the mother board 101 and burrs or chips during division.

  Further, in the wiring board region 102, the dummy region 110, and the disposal margin region 103, the stress generated due to the difference in shrinkage rate during firing is further reduced, and the possibility that the mother substrate 101 warps in a concave shape or a convex shape is reduced. be able to.

  If the mother substrate 101 is very thin and it is difficult to form a dividing groove, for example, an alignment mark is provided on the extension line of the boundary 107 of each wiring substrate region 102, and slicing is performed with reference to the alignment mark. Accordingly, each wiring board region 102 may be divided into individual pieces.

(A) is a top view which shows an example of embodiment of the multi-cavity wiring board of this invention, (b) is the cross section in the AA 'line of the multi-cavity wiring board shown to (a). FIG. (A) is a top view which shows an example of embodiment of the conventional multi-cavity wiring board, (b) is sectional drawing in the BB 'line of the multi-cavity wiring board shown to (a). It is.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Mother board | substrate 102 ... Wiring board area | region 103 ... Discard allowance area | region 104 ... Outer periphery metallization layer 105 ... Recessed part 106 ... Through-conductor 107 ... Boundary 108 ... Plating conduction terminal 109: Wiring conductor 110 ... Dummy region 111 ... Dummy recess

Claims (3)

A plurality of wiring board regions are arranged vertically and horizontally in the center part, and a mother board in which a margin area is formed in the outer periphery part,
The discarded margin region, and a periphery metallized layer formed to surround the wiring board region,
In the outermost periphery of the arrangement of the wiring board regions, dummy areas having the same shape and outer dimensions as the wiring board areas are formed so as to be alternately arranged with the wiring board areas ,
A multi-piece wiring board in which a wiring conductor is formed in the wiring board area, and the wiring conductor is not formed in the dummy area . The material and thickness of the dummy area is the same as the material and thickness of the discarded margin region, a multi-piece circuit board according to claim 1. Wherein the dummy region, a dummy recess of the same shape and size as the circuit board area formed recess is formed, a multi-piece circuit board according to claim 1 or claim 2.

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