JP6114102B2 - Multi-wiring board - Google Patents

Description

  The present invention relates to a multi-piece wiring board in which a plurality of wiring board regions to be individual wiring boards are arranged on a mother board.

  Conventionally, wiring boards used for mounting electronic components and the like are rectangular plate-shaped insulating substrates made of a ceramic sintered body (ceramics) such as an aluminum oxide sintered body or a glass ceramic sintered body, and an upper surface of the insulating substrate. And a wiring conductor provided from the portion where the electronic component is mounted to the lower surface of the insulating substrate.

  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. The multi-cavity wiring board has, for example, a structure in which a plurality of wiring board regions serving as wiring boards are arranged vertically and horizontally on a flat mother board. Such a multi-piece wiring board is divided into individual wiring boards by breaking the mother board along the dividing grooves provided at the boundary of the wiring board region.

  The multi-cavity wiring board is generally manufactured by firing a laminated body in which a plurality of ceramic green sheets on which a metal paste serving as a wiring conductor is printed are laminated. The division grooves are formed on the main surface of the laminated body or the fired mother board by mechanical processing such as cutting along the boundary of the wiring board region.

JP2003-273274A

  However, in the conventional multi-cavity wiring board, when the wiring board is divided (broken) into individual wiring boards, the surface layer portion of the wiring board area is adjacent to the dividing groove. There was a problem that mechanical destruction was likely to occur. This is presumably because stress accompanying breakage of the mother board tends to concentrate on the edge region of the surface layer portion of the wiring board region, and chipping or the like is likely to occur due to this stress.

A multi-piece wiring board according to one aspect of the present invention includes a surface layer portion made of ceramics, an inner layer portion inside the surface layer portion, and a wiring substrate used as an electronic component mounting substrate or a coil component of the surface layer portion. a plurality of respective metal dummy pattern provided in the edge region spaced apart from the boundary of the plurality of wiring substrate regions, the main surface of the metallic dummy pattern of the plurality of wiring substrate regions are provided in the circuit board area to be scribes the upper surface is provided between the external terminals provided on each of the plurality of wiring substrate regions on the lower surface of the opposite side, the external terminals of the lower surface along the boundary of the plurality of wiring substrate regions and a line and which the scribe lines provided in the upper surface to overlap each other, wherein provided on the wiring substrate region adjacent metal dummy Distance turn each other greater than the distance of the external terminals to each other provided on the wiring board adjacent areas.

According to the multi-cavity wiring board of one aspect of the present invention, since the metal dummy pattern is provided in the edge region of the surface layer portion, mechanical destruction such as chipping of the surface layer portion in the edge region is effectively suppressed. . This is considered to be due to the fact that when stress is generated in the edge region, the stress is relaxed by deformation of a metal dummy pattern having a smaller elastic modulus than the surface layer portion made of ceramics. Further, since the distance between the metal dummy patterns provided in the adjacent wiring board regions is larger than the distance between the external terminals provided in the adjacent wiring board regions, the positions of the scribe lines are somewhat adjacent to each other. Even if the position is shifted from the middle position between the patterns toward one metal dummy pattern, the possibility that the scribe line overlaps the metal dummy pattern is reduced. Therefore, the effect of stress relaxation at the time of dividing the mother board by the metal dummy pattern can be obtained more reliably.

(A) is a top view which shows the principal part in the multi-piece wiring board of embodiment of this invention, (b) is sectional drawing in the AA of (a). It is a top view which shows typically an example of the whole multi-piece wiring board which shows the principal part in FIG. It is a top view which shows the principal part in the 1st modification of the multi-cavity wiring board shown in FIG. (A) is a top view which shows the principal part in the 2nd modification of the multi-cavity wiring board shown in FIG. 1, (b) is the bottom view. It is sectional drawing which shows the principal part in the 3rd modification of the multi-cavity wiring board shown in FIG.

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

  FIG. 1A is a top view showing a main part of a multi-cavity wiring board according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA in FIG. FIG. 2 is a top view schematically showing an example of the whole multi-piece wiring board whose main part is shown in FIG. In FIG. 2, details such as a wiring conductor described later are omitted for the sake of clarity.

  In the multi-cavity wiring board of the embodiment, a plurality of wiring board regions 2 are arranged on a mother board 1. The mother board 1 includes a surface layer portion 1a made of ceramics. Moreover, the metal dummy pattern 3 is provided in each edge area | region 2a of the some wiring board area | region 2 about the surface layer part 1a. In FIG. 1A, a region outside the two-dot chain line in the wiring board region 2 is an edge region 2a. A plurality of wiring board regions 2 are arranged on the mother board 1 vertically and horizontally, so that a multi-piece wiring board is basically formed. A multi-piece wiring board is divided into the wiring board regions 2 to produce individual wiring boards. Details of the metal dummy pattern 3 will be described later.

  The wiring board area 2 is an area to be an individual wiring board (not shown). The wiring board region 2 has, for example, a rectangular shape in plan view. The individual wiring board is used as, for example, an electronic component mounting substrate or a coil component. For example, when the wiring board is used as an electronic component mounting board, the central portion of the upper surface of the wiring board region 2 is a mounting portion (no reference numeral) on which the electronic component is mounted.

  Electronic components (not shown) mounted on the wiring board (wiring board region 2) include semiconductor integrated circuit elements such as IC and LSI, LED (light emitting diode), PD (photodiode), and CCD (charge coupled device). Various optical semiconductor elements such as piezoelectric semiconductor elements such as surface acoustic wave elements and crystal oscillators, capacitive elements, resistors, and micromachines (so-called MEMS elements) in which a minute electromechanical mechanism is formed on the surface of a semiconductor substrate Electronic parts are mentioned.

  Note that the individual wiring board may be used for applications other than those for mounting electronic components. As such an application, for example, an application as an independent electronic component such as a coil component can be cited.

  In the wiring board region 2, a wiring conductor 4 is provided from the electronic component mounting portion to the lower surface of the mother board 1. The mother board 1 has a through hole 7 that passes through the mother board 1 in the thickness direction. A part of the wiring conductor 4 is provided on the inner side surface of the through hole 7 and reaches the lower surface of the mother board from the mounting portion through the inner side surface.

The wiring conductor 4 is electrically connected to an electronic component (not shown) mounted on the mounting portion, for example, and functions as a conductive path for electrically connecting it to an external electric circuit (not shown). . In addition, the part located in a mounting part among the wiring conductors 4 becomes a connection pad connected to the electrode of an electronic component. The wiring conductor 4 may include a through conductor (so-called via conductor) that penetrates at least a part of the surface layer portion 1a in the thickness direction.

  External terminals 6 that are electrically connected to an external electric circuit may be provided on the lower surface of the mother board 1 in each wiring board region 2. The external terminal 6 may be composed of a portion of the wiring conductor 4 provided on the lower surface of the mother board 1.

  The electrical connection between the electronic component and the wiring conductor 4 is performed by, for example, electrically connecting an electrode (not shown) of the electronic component to a portion of the wiring conductor 4 that is provided in the mounting portion, such as solder. This can be done by joining the wiring conductor 4 and the electrode through a material (not shown).

  The wiring conductor 4 is not limited to a function as a conductive path that electrically connects an electronic component and an external electric circuit, and may include a portion having a function such as a coil.

  The wiring conductor 4 and the external terminal 6 are made of, for example, a metal material such as tungsten, molybdenum, manganese, copper, silver, palladium, platinum, or gold, or an alloy material containing these metal materials as a main component.

  In the multi-cavity wiring board of the embodiment, the mother board 1 has a surface layer portion 1a made of ceramics. The surface layer portion 1 a is a main surface of the mother substrate 1 and a portion close to the main surface (a shallow portion) of the mother substrate 1. The surface layer portion 1a functions as, for example, an insulating base portion for providing a wiring conductor 4 necessary as a multi-piece wiring board and a piece wiring board.

  The surface layer portion 1a is made of ceramic 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. Is formed.

  Further, the inner portion of the mother board 1 relative to the surface layer portion 1a is an inner layer portion 1b. The inner layer portion 1b may be made of the same ceramic as the surface layer portion 1a, or may be made of a material different from that of the surface layer portion 1a.

  For example, as an example of the inner layer portion 1b made of a material different from the surface layer portion 1a made of ceramic, an inner layer portion 1b made of a ferrite material can be cited. When the inner layer portion 1b is made of a ferrite material, the magnetic permeability in the wiring board region 2 is increased. Therefore, for example, when the wiring conductor 4 includes a function as a coil, the function can be enhanced.

Examples of such ferrite materials are ZnFe ₂ O ₄ , MnFe ₂ O ₄ , FeFe ₂ O ₄ , CoFe ₂ O ₄ , NiFe ₂ O ₄ , BaFe ₂ O ₄ , SrFe ₂ O ₄ or CuFe ₂ O ₄ . .

  For dividing a multi-piece wiring board into individual wiring board areas 2, for example, a scribe line 5 is provided on the main surface of the mother board 1 along the boundary of the wiring board area 2, and the mother board is formed along the scribe line 5. This is done by breaking 1. The scribe line 5 can be formed, for example, by cutting out the main surface of the mother board 1 along the boundary of the wiring board region 2 with a scriber. The scriber is manufactured by using a blade having such a hardness that the surface layer portion 1a made of ceramics having high hardness such as glass ceramics can be cut out in the depth direction.

For example, if the surface layer portion 1a is made of a glass ceramic sintered body and the inner layer portion 1b is made of a ferrite material, the mother substrate 1 can be manufactured as follows.

First, a raw material powder containing aluminum oxide as a main component and added with powders such as silicon oxide, magnesium oxide, and calcium oxide is kneaded with an organic solvent and a binder, and formed into a sheet by a molding method such as a doctor blade method or a lip coater method. Molding to produce a ceramic green sheet. Next, a ferrite material is used as a raw material powder, and is similarly molded into a sheet shape together with an organic solvent, a binder, and the like to produce a ferrite green sheet. Then, the mother substrate 1 can be manufactured by laminating the ceramic green sheet, the ferrite green sheet, and the ceramic green sheet in order, and firing the laminated body at a firing temperature of about 850 to 1000 ° C.

  If the wiring conductor 4 and the external terminal 6 are made of, for example, silver, a metal paste prepared by kneading tungsten powder together with an organic solvent and a binder is used for the ceramic green sheet that becomes the surface layer portion 1a of the mother board 1. It can be formed by printing and co-firing with the laminate.

  The metal dummy pattern 3 is for suppressing mechanical breakage such as chipping in the edge region of the wiring substrate region 2 when the mother substrate 1 is divided along the scribe line 5. This is considered to be because the stress generated in the edge region 2a when the mother substrate 1 is divided (ruptured) is relieved by providing the metal dummy pattern 3 as described above.

  That is, since the elastic modulus of the metal dummy pattern 3 is smaller than the elastic modulus of the surface layer portion 1a made of ceramics, the stress generated in the edge region 2a is alleviated by deformation of the metal dummy pattern, etc. Etc. are considered to be suppressed.

  The metal dummy pattern 3 is electrically independent from the wiring conductor 4. That is, the metal dummy pattern 3 is electrically independent of an electronic circuit mounted on the wiring board region 2 (individual wiring board) and an electric circuit such as an external electric circuit. As a result, the possibility that the metal dummy pattern 3 affects the electrical characteristics and the like of the individual wiring board is reduced.

  The metal dummy pattern 3 can be formed by the same method using the same material as that of other conductor portions (metalized layer or the like) such as the wiring conductor 4 and the external terminal 6, for example. The metal dummy pattern 3 may be made of a metal material different from that of the wiring conductor 4 and the external terminal. For example, when the wiring conductor 4 is made of silver, the metal dummy pattern 3 may be made of silver, or made of a mixed material in which a metal such as palladium or an inorganic powder such as glass is dispersed in silver. It does not matter.

  The metal dummy pattern 3 is preferably closer to the edge of the wiring board region 2 adjacent to the scribe line 5 in terms of stress relaxation. In other words, the metal dummy pattern 3 is preferably located at the outer peripheral portion of the edge region 2a. If the metal dummy pattern 3 includes a portion existing in the edge region 2a, a part of the metal dummy pattern 3 protrudes inward (in the direction of the mounting portion) from the edge region 2a, for example, as shown in FIG. It doesn't matter.

  In terms of stress relaxation, the metal dummy pattern 3 is preferably closer to the surface of the mother substrate 1 where chipping or the like is likely to occur. In other words, the metal dummy pattern 3 is preferably located on the upper side of the surface layer portion 1a.

The thickness of the metal dummy pattern 3 is preferably as thick as possible for stress relaxation. However, if the metal dummy pattern 3 becomes too thick, there is a possibility that characteristics such as electrical insulation between the metal dummy pattern 3 and the wiring conductor 4 are lowered. The thickness of the metal dummy pattern 3 may be set to about 1/3 to 1/2 of the thickness of the surface layer portion 1a, for example.

  In addition, if the mother substrate 1 is formed by laminating a layer made of ceramic and a layer made of a ferrite material as described above, and a layer made of ferrite is laminated at the center in the thickness direction, the layer made of ceramic is It corresponds to the surface layer part 1a. Further, when all the layers included in the mother substrate 1 are layers made of the same ceramic, the depth from the main surface (upper and lower surfaces) of the mother substrate 1 to about 15% of the thickness of the mother substrate 1 is obtained. This portion corresponds to the surface layer portion.

  Further, when the metal dummy pattern 3 is provided in each corner area of the plurality of wiring board areas 2, chipping at the time of dividing the mother board 1 can be more effectively suppressed. This is because the stress at the time of dividing the mother board 1 tends to concentrate on the corner area of the rectangular wiring board area 2. Since the metal dummy pattern 3 suitable for stress relaxation exists in such a portion where stress is likely to concentrate, the stress is more effectively relaxed, and the chipping in the edge region 2a of the wiring board region 2 is more effective. Is suppressed.

  In this case, if the metal pattern 3 is provided only in the corner area (the metal pattern 3 is not provided in the side area), the range in which the metal dummy pattern 3 is provided can be further reduced. For this reason, it is easier to secure a space for providing the wiring conductor 4 and the like, which is advantageous in terms of downsizing the individual wiring board. It is also advantageous in terms of economy.

  However, the metal dummy pattern 3 may be provided in the side region of the wiring board region 2 with priority given to stress relaxation, for example, or may be provided over the entire periphery of the edge region 2a.

  FIG. 3 is a top view showing a main part in a first modification of the multi-cavity wiring board shown in FIG. In FIG. 3, the same parts as those in FIG.

  In the example shown in FIG. 3, the metal dummy pattern 3 is separated from the boundaries (positions of the scribe lines 5) of the plurality of wiring board regions 2. In such a case, when forming the scribe line 5, possibility that the metal dummy pattern 3 will adhere to a scriber will be reduced. Therefore, for example, the possibility that the metal component of the metal dummy pattern 3 sticks to the blade of the scriber and the formation of the scribe line 5 by the scriber is hindered is reduced.

  In such a metal dummy pattern 3 that is separated from the boundary of the wiring board region 2, a metal paste printing pattern (screen printing plate or the like) that becomes the metal dummy pattern 3 is a pattern corresponding to the pattern. Can be formed.

  In this case, the distance of the metal dummy pattern 3 from the boundary of the wiring board region 2 may be appropriately set according to the width of the scriber blade used for forming the scribe line. However, if the separation distance of the metal dummy pattern 3 from the boundary of the wiring board region 2 becomes too large, the effect of stress relaxation by the metal dummy pattern 3 may be reduced. Therefore, the separation distance of the metal dummy pattern 3 from the boundary of the wiring board region 2 is set to about 2 to 3 times the width of the scriber blade, for example.

  FIG. 4A is a top view showing the main part of the second modification of the multi-piece wiring board shown in FIG. 1, and FIG. 4B is a bottom view of FIG. 4, parts similar to those in FIG. 1 are denoted by the same reference numerals.

  In the example shown in FIG. 4, as described above, the multi-piece wiring board has a main surface (for example, a lower surface) opposite to the main surface (for example, the upper surface) on which the metal dummy patterns 3 of the plurality of wiring substrate regions 2 are provided. 1 further includes external terminals 6 provided in each of the plurality of wiring board regions 2. As described above, the external terminal 6 is made of silver or the like, and has a function of electrically connecting the individual wiring board to an external electric circuit.

  If such an external terminal 6 is provided, this external terminal 6 produces the same effect as the metal dummy pattern 3. That is, when the mother board 1 is divided along the boundary (scribe line 5) of the wiring board region 2, the stress accompanying the division is caused by the edge of the wiring board area 2 in the surface layer portion 1a on the lower surface side of the mother board 1. Even if it occurs in the region 2 a, the stress is relieved by the external terminal 6. In this case, it is not necessary to provide the metal dummy pattern 3 in the edge region 2a of the wiring board region 2 in the surface layer portion 1a on the lower surface side of the mother board 1, and the productivity and economy as a multi-piece wiring board are improved. Can do.

  Further, when the external terminals 6 are provided, the distance a between the metal dummy patterns 3 provided in the adjacent wiring board regions 2 and the distance b between the external terminals 6 are different. Specifically, the distance a between the metal dummy patterns 3 is larger than the distance b between the external terminals 6 between the adjacent wiring board regions 2. In other words, the external terminal 6 is closer to the scribe line than the metal dummy pattern 3.

  In this case, for example, even if a slight misalignment occurs between the metal dummy pattern 3 and the external terminal 6 due to, for example, a stacking deviation of the ceramic green sheets, when the mother substrate 1 is divided by the metal dummy pattern 3 The effect of stress relaxation can be obtained more reliably.

That is, when the scribe lines 5 are provided on both main surfaces of the mother board 1, it is first necessary as a precondition that the upper and lower scribe lines 5 are positioned so as to overlap each other in a plan view. On the other hand, if there is a positional deviation in plan perspective between the metal dummy pattern 3 and the external terminal 6, the scribe line 5 is biased toward one of the metal dummy patterns 3 and the metal dummy pattern 3. There is a possibility that the effect of stress relaxation cannot be obtained. At this time, if the distance a between the metal dummy patterns 3 is greater than the distance b between the external terminals 6, the position of the scribe line 5 is somewhat slightly from the middle position between the adjacent metal dummy patterns 3 to one of the metal dummy patterns 3. Even if it deviates, the possibility that the scribe line 5 overlaps the metal dummy pattern 3 is reduced. Therefore, in this case, the effect of stress relaxation at the time of dividing the mother board 1 by the metal dummy pattern 3 can be obtained more reliably.

  FIG. 5 is a cross-sectional view showing a main part in a third modification of the multi-cavity wiring board shown in FIG. 5, parts similar to those in FIG. 1 are denoted by the same reference numerals. In this example, the multi-piece wiring board has the inner layer portion 1b made of a material different from ceramics as described above. Such an inner layer portion 1b is made of a ferrite material as described above, for example. The ferrite material is also a kind of ceramic sintered body, but in this embodiment, it is treated as a material different from the ceramic forming the surface layer portion 1a, and the surface layer portion 1a and the inner layer portion 1b are distinguished.

  When such an inner layer portion 1b is provided, a second metal dummy pattern 8 is further provided in each edge region 2a of the plurality of wiring board regions 2 between the surface layer portion 1a and the inner layer portion 1b. It may be. In this case, when the stress at the time of dividing the mother substrate 1 is concentrated between the surface layer portion 1a and the inner layer portion 1b made of different materials, the stress can be more effectively reduced. Therefore, in this case, it is possible to provide a multi-piece wiring board in which defects such as chipping in the surface layer portion 1a and the inner layer portion 1b are more effectively suppressed.

  The second metal dummy pattern 8 can be formed by the same method using the same material as that of the metal dummy pattern 3, for example. The second metal dummy pattern 8 may also be separated from the boundary of the wiring board region 2. In this case, when the multi-piece wiring board is divided into individual wiring boards, that is, when the mother board 1 is broken in the thickness direction, it is made of a metal material that is hard to break compared to the surface layer portion 1a and the inner layer portion 1b. The possibility that the second metal dummy pattern 8 is prevented from breaking is further reduced.

  Note that the multi-piece wiring board of the present invention is not limited to the example of the above embodiment, and various modifications can be made without departing from the gist of the present invention. For example, it may be a multi-piece wiring board having divided grooves, in which divided grooves (not shown) are provided at the boundary of the wiring board region 2 at the stage of the ceramic green sheet to be the mother board 1. In this case, the plurality of wiring board regions 2 are divided into individual wiring boards along the dividing grooves. Also during this division, the stress is relieved by the metal dummy pattern 3, and the occurrence of chipping in the surface layer portion 1a and the like is suppressed.

  Further, a plating layer such as nickel and gold may be applied to the exposed surfaces of the metal dummy pattern, the wiring conductor 4 and the external terminal 6 in order to improve the suppression of oxidation. In addition, as shown in FIG. 2, for example, a dummy area (no reference numeral) surrounding a plurality of wiring board areas 2 is provided on the outer peripheral portion of the mother board 1 so that it is easier to handle as a multi-piece wiring board. Or the wiring line for plating (not shown) may be more easily routed.

  Further, when the external terminal 6 is not provided, the metal dummy pattern 3 (the lower surface side is not shown) is provided in the edge region 2a for each surface layer portion 1a on both main surfaces (upper and lower surfaces) of the mother board 1. It may be done. As a result, the occurrence of chipping or the like in the edge region 2a is reduced on both main surfaces of the mother substrate 1. Note that the position of the external terminal 6 in this case is set, for example, at the center of each of the wiring board regions 2 on the inner surface of the through hole 7 or the lower surface of the mother board 1.

DESCRIPTION OF SYMBOLS 1 ... Mother board 1a ... Surface layer part 2 ... Wiring board area | region 2a ... Edge area | region 3 ... Metal dummy pattern 4 ... Wiring conductor 5 ... Scribe line 6 ... External terminal 7 ... through hole 8 ... second metal dummy pattern

Claims (3)

A surface layer made of ceramics;
An inner layer part inside the surface layer part,
Of the surface layer portion, and a plurality of said plurality of metal dummy pattern provided at a distance from the boundary of the wiring substrate regions in each of the edge region of the wiring substrate region serving as a wiring substrate used as an electronic component carrier or the coil component ,
External terminals provided in each of the plurality of wiring board regions on the lower surface, which is the main surface opposite to the upper surface that is the main surface provided with the metal dummy pattern of the plurality of wiring board regions ,
A scribe line provided between the external terminals on the lower surface along boundaries of the plurality of wiring board regions, and a scribe line provided on the upper surface so as to overlap with each other in a plan perspective .
The multi-piece wiring board, wherein a distance between the metal dummy patterns provided in the adjacent wiring board regions is larger than a distance between the external terminals provided in the adjacent wiring board regions. The multi-piece wiring board according to claim 1, wherein the metal dummy pattern is provided in each corner area of the plurality of wiring board areas. An inner layer made of a material different from ceramics,
The second metal dummy pattern provided in each edge region of the plurality of wiring board regions between the surface layer part and the inner layer part is further provided. The multi-cavity wiring board described in 1.

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