JP5653323B2 - Molded body and multi-cavity wiring board - Google Patents

Description

  The present invention relates to a molded body and a multi-cavity wiring board for manufacturing a wiring board for mounting electronic components such as semiconductor elements and light emitting elements.

  2. Description of the Related Art Conventionally, a ceramic substrate is used as a wiring board on which electronic components are mounted and incorporated in an electronic device, and wiring conductors are arranged on the surface and inside of the wiring board. An electronic device is manufactured by electrically connecting an electronic component mounted on a wiring board and a wiring conductor.

  Some of such wiring boards have a metal body embedded for the purpose of heat dissipation or the like (see, for example, Patent Document 1). Such a metal body is, for example, for releasing heat generated by an electronic component mounted on the wiring board to the outside of the wiring board to improve heat dissipation.

  In addition, with the recent demand for thinner and smaller electronic devices, the size of such wiring boards has been reduced. In order to efficiently manufacture a plurality of wiring boards, a large number of such wiring boards can be obtained. Manufacturing is performed by dividing the wiring board. The multi-cavity wiring board is obtained by arranging a plurality of wiring board regions to be a wiring board on a large-area mother board in the vertical and horizontal directions. Note that such multi-cavity wiring boards sometimes warp so as to be convex or concave due to firing shrinkage of ceramics. Further, in the wiring board, the metal body may be arranged to be biased from the center of the wiring board to one of the upper, lower, left and right sides in a plan view.

JP 2009-71013 A

  However, when a multi-cavity wiring board is manufactured to obtain a wiring board in which metal bodies are arranged in an uneven manner, the multi-cavity wiring board is warped and becomes the most recessed area or the most convex of the multi-cavity wiring board. The region sometimes deviated from the center of the multi-piece wiring board in the direction in which the metal body is biased. In such a multi-cavity wiring board, when mounting electronic components or resin molding, placing a mold on the multi-cavity wiring board may cause the multi-cavity wiring board to break. It was.

  The present invention has been devised in view of the above-mentioned problems of the prior art, and its purpose is to form the most concave of the multi-cavity wiring board even if the multi-cavity wiring board is warped and becomes concave or convex. An object of the present invention is to provide a multi-cavity wiring board in which the area or the most convex area is located at the center, and a molded body for producing such a multi-cavity wiring board.

The molded body of the present invention has a rectangular shape in plan view, and includes a plurality of ceramic green sheets including a plurality of wiring board regions arranged in the vertical direction and the horizontal direction, and the plurality of wiring board regions. Embedded in each of the plurality of wiring board regions, and provided with a metal body that is unevenly distributed in the vertical direction, and is disposed at an upper end in the vertical direction of the plurality of wiring board regions. The distance from the metal body provided in the wiring board area to the upper side of the ceramic green sheet is provided in the wiring board area disposed at the lower end in the vertical direction among the plurality of wiring board areas. It is equal to the distance from the said metal body to the lower side of the said ceramic green sheet.

  The multi-cavity wiring board of the present invention has a rectangular shape in plan view, and includes a mother board including a plurality of wiring board areas arranged in the vertical direction and the horizontal direction, and the plurality of wiring board areas. A metal sintered body that is embedded in each of the plurality of wiring board regions and is provided in a localized manner in the vertical direction, and has an upper end in the vertical direction among the plurality of wiring board regions. The distance from the metal sintered body provided in the wiring board region disposed in the upper side of the mother board to the wiring board region disposed at the lower end in the vertical direction among the plurality of wiring board regions. It is equal to the distance from the provided metal sintered body to the lower side of the mother substrate.

  According to the molded body of the present invention, the distance from the metal body provided on the wiring board region disposed at the upper end in the vertical direction among the plurality of wiring board regions to the upper side of the ceramic green sheet is equal to the plurality of wiring board regions. Among them, since it is equal to the distance from the metal body provided in the wiring board region arranged at the lower end in the vertical direction to the lower side of the ceramic green sheet, when the ceramic green sheet is fired to obtain a multi-piece wiring board, many Even if the multi-cavity wiring board is warped, the most recessed area or the most convex area of the multi-cavity wiring board can be positioned at the center of the multi-cavity wiring board.

  According to the multi-cavity wiring board of the present invention, the distance from the metal body provided in the wiring board area disposed at the upper end in the vertical direction among the plurality of wiring board areas to the upper side of the mother board is a plurality of wiring boards. Since it is equal to the distance from the metal body provided in the wiring board area disposed at the lower end in the vertical direction to the lower side of the mother board, even if the multi-cavity wiring board warps, the multi-cavity wiring board The most concave region or the most convex region can be placed in the center of the wiring board.

(A) is a top view which shows an example of 1st Embodiment of the molded object of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows the other example of 1st Embodiment of the molded object of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows the other example of 1st Embodiment of the molded object of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows the other example of 1st Embodiment of the molded object of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows the other example of 1st Embodiment of the molded object of this invention, (b) is sectional drawing in the AA of (a), (c) is ( It is sectional drawing in the BB line of a). (A) is a top view which shows an example of 1st Embodiment of the multi-piece wiring board of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows an example of 2nd Embodiment of the molded object of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows an example of 2nd Embodiment of the multi-piece wiring board of this invention, (b) is sectional drawing in the AA of (a).

  Several exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 6, the upward direction refers to the positive direction of the virtual y axis.

(First embodiment)
The molded body in the first embodiment of the present invention has a rectangular shape in plan view as in the examples shown in FIGS. 1 to 5, and a plurality of wiring board regions arranged in the vertical direction and the horizontal direction Embedded in each of the plurality of ceramic green sheets 1 including 1a and the plurality of wiring board regions 1a, and unevenly distributed in the vertical direction in each of the plurality of wiring substrate regions 1a. The distance from the metal body 2 provided in the wiring board area | region 1a arrange | positioned at the upper end of the vertical direction among several wiring board area | regions 1a to the upper side of the ceramic green sheet 1 is provided. L1 is a distance L2 from the metal body 2 provided in the wiring board region 1a disposed at the lower end in the vertical direction among the plurality of wiring board regions 1a to the lower side of the ceramic green sheet 1. Shii is intended.

  Note that the distance L1 from the metal body 2 to the upper side of the ceramic green sheet 1 and the distance L2 from the metal body 2 to the lower side of the ceramic green sheet 1 in the first embodiment are equal in length, but variations in manufacturing. An error of about 0.1 mm caused by the above is included.

  Further, in the molded body of the first embodiment, in the above configuration, the metal body 2 extends in the lateral direction (x direction) through the center of the ceramic green sheet 1 in a plan view as in the example shown in FIG. When the imaginary straight line (CC line) is arranged symmetrically with respect to the line, the stress due to the shrinkage of firing is sandwiched between the CC line when the molded body is fired to produce a multi-piece wiring board. Since the multi-cavity wiring board is warped, it is effective to position the most recessed area or the most convex area on the CC line when the multi-cavity wiring board warps.

  Further, the molded body of the first embodiment is fired when the metal bodies 2 are arranged at equal intervals in the vertical direction (y direction) as in the example shown in FIG. When the multi-cavity wiring board is manufactured, the stress due to the firing shrinkage is distributed substantially evenly in the wiring board region 1a. Therefore, when the multi-cavity wiring board is warped, the multi-cavity wiring board is most recessed. It is effective to place a large number of regions or the most convex regions at the center of the wiring board.

  Further, in the above configuration, the molded body according to the first embodiment is arranged at the lower end from the wiring board region 1a arranged at the upper end in the vertical direction (y direction) in plan view as in the example shown in FIG. When the metal bodies 2 are arranged symmetrically across the boundaries of the plurality of wiring board regions 1a in the plurality of wiring board regions 1a arranged adjacent to each other in the vertical direction (y direction) over the wiring board region 1a, When the molded body is fired to produce a multi-cavity wiring board, stress due to firing shrinkage is applied to the adjacent wiring board region 1a substantially evenly, so that when the multi-cavity wiring board warps, the multi-cavity wiring This is effective for positioning the most concave region or the most convex region of the substrate at the center of the wiring substrate.

  The ceramic green sheet 1 obtains a slurry obtained by adding an organic binder and an organic solvent to a ceramic powder, and a predetermined amount of a plasticizer or a dispersant as required, and this is made of a resin such as PET (polyethylene terephthalate) or paper. It is prepared by applying onto a support by a forming method such as a doctor blade method, a lip coater method or a die coater method, forming it into a sheet, and drying it by a drying method such as hot air drying, vacuum drying or far-infrared drying. .

Examples of the ceramic powder include aluminum oxide (Al ₂ O ₃ ) powder, aluminum nitride (AlN) powder, glass ceramic powder, and the like, which are appropriately selected according to the characteristics required for the wiring board 7.

When the ceramic powder is an aluminum oxide powder or aluminum nitride powder, a powder of a component serving as a sintering aid such as silicon oxide (SiO ₂ ) or magnesium oxide (MgO) is added, and manganese oxide (MnO) is used as a colorant. ) Etc. may be added.

When the ceramic powder is a glass ceramic powder, the glass powder and the filler powder are mixed at a mass ratio of 10:90 to 99: 1, preferably 40:60 to 80:20. The glass powder of the glass ceramic powder, may be used those conventionally used in glass ceramics, for example, _SiO 2 _-B 2 _{O 3 based, SiO 2 -B 2 O 3 -Al} 2 O 3 system, SiO _{2 -B 2 O 3 -Al 2 O 3} -MO -based (where, M represents Ca, Sr, Mg, Ba, or _{Zn.), SiO 2 -Al 2} O 3 -M1O-M 2 O system (however, M1 And M2 are the same or different and each represents Ca, Sr, Mg, Ba or Zn.), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —M ₁ O—M ₂ O system (where M 1 and M 2 are the same as above) ), SiO ₂ —B ₂ O ₃ —M3 ₂ O system (where M3 represents Li, Na or K), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —M3 ₂ O system (provided that M3 and above Flip it.), Pb-based, powder glass Bi system and the like are used.

Further, as the filler powder of the glass ceramic powder, what is conventionally used for glass ceramics may be used, for example, a composite oxide of Al ₂ O ₃ , SiO ₂ , ZrO ₂ and an alkaline earth metal oxide, Ceramic powders such as composite oxides of TiO ₂ and alkaline earth metal oxides, composite oxides containing at least one of Al ₂ O ₃ and SiO ₂ (cristobalite, quartz) (for example, spinel, mullite, cordierite) Can be mentioned.

  As the organic binder, those conventionally used for ceramic green sheets may be used. For example, acrylic (acrylic acid, methacrylic acid or a single aggregate or copolymer of esters thereof, specifically, acrylic ester. Copolymer, methacrylic acid ester copolymer, acrylic acid ester-methacrylic acid ester copolymer, etc.), polyvinyl butyral type, polyvinyl alcohol type, acrylic-styrene type, polypropylene carbonate type, cellulose type homopolymer or the like A copolymer is mentioned. In view of decomposability and volatility in the firing step, an acrylic binder is more preferable. Also, the amount of organic binder added varies depending on the ceramic powder, but it may be an amount that is easy to be decomposed and removed during firing and that the ceramic powder is dispersed and the green sheet is easy to handle and process. About 10 to 20% by mass is desirable.

The solvent contained in the slurry is made of organic materials such as hydrocarbons, ethers, esters, ketones, alcohols, etc. so that a slurry having a viscosity suitable for green sheet molding can be obtained by dispersing ceramic powder and organic binder. A solvent and water are mentioned. Among these, solvents having a high evaporation coefficient such as toluene, methyl ethyl ketone, and isopropyl alcohol are preferable because the drying process after slurry application can be completed in a short time. The solvent is added in an amount of 30 to 100% by mass with respect to the ceramic powder, so that the viscosity is such that the slurry can be satisfactorily coated on the support, specifically about 3 to 100 cps. It is desirable to make it.

  The ceramic green sheet 1 includes a laminate of a plurality of ceramic green sheets. Such a ceramic green sheet 1 composed of a plurality of layers is formed by preparing a plurality of ceramic green sheets, laminating them and pressing them.

  Next, as in the example shown in FIGS. 1 to 5, the metal body 2 is embedded in the wiring board region 1 a of the ceramic green sheet 1 and the wiring conductor pattern 3 is disposed. Note that either the embedding of the metal body 2 or the arrangement of the wiring conductor pattern 3 may be performed first.

  In order to embed the metal body 2 in the ceramic green sheet 1, a hole is provided in the ceramic green sheet 1, and the metal body 2 may be disposed in the hole.

  The hole in which the metal body 2 is embedded can be formed by punching by a die or punching or laser processing. At this time, the metal body 2 may be exposed on the upper surface, the lower surface, or both the upper and lower surfaces of the molded body. For example, when the corner portion is formed in a rectangular shape having a circular arc shape or a circular bottom surface in plan view, the bottom surface of the columnar metal body 2 may be exposed on the upper surface or the lower surface of the molded body. When the metal body 2 is exposed on the upper surface or the lower surface of the molded body, the metal body 2 is deformed in the thickness direction of the molded body when the molded body is baked as compared with the case where the metal body 2 is not exposed. Therefore, it is effective for suppressing deformation in the surface direction of the molded body.

  The metal body 2 is made of a metal sheet or a metal paste, and can be arranged by filling the hole of the ceramic green sheet 1 with the metal sheet or the metal paste.

  When the metal body 2 is made of a metal sheet, the metal sheet is formed in the same shape as the hole of the ceramic green sheet 1 in a plan view and the same thickness as the depth of the hole of the ceramic green sheet 1. It suffices if it is buried so as to fill the holes.

  When the metal sheet is embedded in the ceramic green sheet 1 by punching and simultaneously embedded, a molded body can be produced efficiently.

  For example, a metal sheet is placed on the upper surface of the ceramic green sheet 1 in which a through hole is formed, and a metal mold and a ceramic green sheet are formed from the metal sheet side using a punching die that forms a through hole in the ceramic green sheet 1. When a through hole is punched into the metal sheet, a metal sheet punched in the same size as the through hole can be fitted into the through hole of the ceramic green sheet 1.

  Moreover, when the metal body 2 consists of a metal paste, the metal paste should just be filled and arrange | positioned at the hole of the ceramic green sheet 1. FIG. Moreover, when using a metal paste, the metal paste should just be adjusted to the viscosity hold | maintained at the hole of the ceramic green sheet 1, However, The hole of the ceramic green sheet 1 should have a bottom. preferable.

  In the case of using a metal sheet as the metal body 2, the metal sheet is obtained by adding an organic binder and an organic solvent to the metal powder, and adding a predetermined amount of a plasticizer and a dispersant as required to obtain a slurry. Polyethylene terephthalate) and other paper or paper supports are coated by a molding method such as the doctor blade method, lip coater method or die coater method, and then molded into a sheet, warm air drying, vacuum drying, far infrared drying, etc. It is produced by drying by the drying method.

  Examples of the metal powder include tungsten (W), molybdenum (Mo), manganese (Mn), gold (Au), silver (Ag), copper (Cu), palladium (Pd), and platinum (Pt). Or the powder which consists of 2 or more types is mentioned, According to the characteristic requested | required, it selects suitably. In addition, when a metal powder consists of 2 or more types, any form, such as mixing, an alloy, and a coating, may be sufficient. For example, when a metal body 2 in which Cu powder and W powder are mixed is used, a sintered metal body 12 made of copper tungsten (CuW) having excellent heat dissipation can be obtained.

  As the organic binder used for the metal sheet and the solvent contained in the slurry, the materials used for the ceramic green sheet can be used.

The amount of the organic binder to be added varies depending on the metal powder, but it may be an amount that can be easily decomposed and removed during firing, is dispersed in the metal powder, and has good handling and workability of the green sheet. From about 20% by mass is desirable.

The amount of the solvent is 30 to 100% by mass based on the metal powder, so that the slurry can be satisfactorily coated on the support, specifically 3 to 100 cps.
It is desirable to be about s.

  As the organic binder used for the metal paste, those conventionally used for the metal paste can be used. For example, acrylic (acrylic acid, methacrylic acid or their homopolymers or copolymers, specifically Acrylic ester copolymer, methacrylic ester copolymer, acrylic ester-methacrylic ester copolymer, etc.), polyvinyl butyral, acrylic-styrene, polypropylene carbonate, cellulose and other homopolymers or A copolymer is mentioned. In view of decomposability and volatility in the firing step, acrylic and alkyd organic binders are more preferable.

  The amount of the organic binder added varies depending on the metal powder, but may be any amount that can be easily decomposed and removed during firing and can disperse the metal powder. It is desirable to be.

  The solvent used for the metal paste is not particularly limited as long as the metal powder and the organic binder can be well dispersed and mixed, and examples thereof include terpineol and butyl carbitol acetate. In view of formability after printing and drying properties, it is preferable to use a low boiling point solvent. The solvent is added in an amount of 4 to 15% by mass with respect to the metal powder, and is adjusted to about 15000 to 40000 cps.

  In addition, in order to match the firing shrinkage behavior and shrinkage rate of the ceramic green sheet 1 during firing, or to ensure the bonding strength of the wiring conductor 13 after firing, the metal paste is added with glass or ceramic powder. Also good.

  Further, as in the example shown in FIG. 4, the metal body 2 is different in size between the upper surface side and the lower surface side of the molded body in a plan view, and by providing a step between the upper surface side and the lower surface side. When the molded body is fired, the contact area between the mother substrate 11 and the metal sintered body 12 can be increased. In order to produce the metal sintered body 12 having such a shape, the ceramic green sheet 1 is formed of a plurality of ceramic green sheets, a first through hole is formed in the upper ceramic green sheet, and the lower ceramic green sheet is formed. A second through-hole having a diameter larger than that of the first through-hole is formed in the first through-hole, a metal body 2 having a size corresponding to each of these through-holes is embedded, and upper and lower ceramic green sheets are stacked and added. It can be formed by pressing.

  When the size of the metal body 2 is different between the upper surface side and the lower surface side of the formed body, the distance L1 from the metal body 2 to the upper side of the ceramic green sheet 1 on the upper surface side and the lower side of the ceramic green sheet 1 from the metal body 2 The distance L2 from the metal body 2 to the upper side of the ceramic green sheet 1 on the lower surface side and the distance L4 from the metal body 2 to the lower side of the ceramic green sheet 1 are set to L3 = L4. .

  Further, the metal body 2 may be unevenly distributed in the lateral direction as in the example shown in FIG. In this case, in a plan view, the distance L5 from the metal body 2 to the left side of the ceramic green sheet 1 and the distance L6 from the metal body 2 to the right side of the ceramic green sheet 1 are L5 = L6. In the case of L3 = L4 and L5 = L6, as in the case of L1 = L2, each distance includes an error due to a variation of about 0.1 mm in the manufacturing process.

The wiring conductor pattern 3 is electrically connected to the wiring conductor 13 which becomes a connection electrode electrically connected to each electrode by connection means such as wire bonding of electronic components, and the wiring conductor 13 of the external circuit board via a bonding material such as solder. Wiring conductor 13 to be a connection pad to be connected, a through conductor for electrically connecting the connection electrode and the connection pad, and a wiring conductor 13 to be an internal wiring layer routed in the substrate .

  Such a wiring conductor pattern 3 is formed, for example, by forming a through-hole for the wiring conductor pattern 3 to be a through conductor in the ceramic green sheet 1 by punching, punching with a mold, or laser processing. A conductive paste for the wiring conductor pattern 3 is embedded by screen printing or press filling to form the wiring conductor pattern 3 to be a through conductor, and the wiring conductor pattern 3 to be a through conductor on the upper surface or the lower surface of the ceramic green sheet 1 is exposed. A conductor paste for the wiring conductor pattern 3 to be a wiring conductor layer is printed in a predetermined pattern shape by a printing method such as a screen printing method or a gravure printing method on the formed portion, thereby forming a thickness of about 10 μm to 20 μm. .

  Conductor paste is filled with metal paste by adding an appropriate organic binder and solvent, and uniformly dispersed by a kneading means such as a ball mill or a planetary mixer. It is produced by adjusting the viscosity to be suitable for.

  Such a conductor paste can be manufactured by the same method using the same material as the metal paste described above.

Next, a compact is produced by pressurizing the ceramic green sheet 1 on which the wiring conductor pattern 3 is formed on the main surface and inside. When laminating, the respective through holes are laminated so as to overlap each other in plan view. Pressurization to the compact at this time is performed while heating as necessary. The pressure and heating conditions vary depending on the type and amount of the organic binder used, but are generally a pressure of 2 to 20 MPa and a temperature of 30 to 100 ° C. Further, these ceramic green sheets 1 are placed on a metal body made of stainless steel or the like, and are added by an elastic body made of metal or rubber made of stainless steel or the like disposed above the ceramic green sheet 1. Pressed.

  In the examples shown in FIGS. 1 to 5, the molded body is produced by arranging the metal body 2 and the wiring conductor pattern 3 on one ceramic green sheet 1. You may produce a molded object by preparing 1 and laminating | stacking. When laminating, in order to improve the adhesion between the ceramic green sheets 1, an adhesive obtained by mixing a solvent with an organic binder, a plasticizer, or the like may be used.

  Further, when a molded body is produced by laminating a plurality of ceramic green sheets 1, the wiring conductor patterns 3 as the through conductors may be directly connected to each other, but the wiring conductor patterns 3 are more connected to each other. In order to make it favorable, it is preferable to form the wiring conductor pattern 3 wider than these patterns between the wiring conductor patterns 3 to be the through conductors.

  By firing the molded body thus produced, a multi-cavity wiring board such as the example shown in FIG. 6 can be produced. By firing the molded body, the ceramic green sheet 1 is the mother substrate 11, the metal body 2 is the sintered metal body 12, the wiring conductor pattern 3 is the wiring conductor 13, and the metal frame pattern 4 is the metal frame body. Become 14. Further, the example shown in FIG. 6 shows a multi-piece wiring board on which the electronic component 17 is mounted.

The multi-cavity wiring board in the first embodiment has a rectangular shape in plan view, and includes a mother board 11 including a plurality of wiring board regions arranged in the vertical direction and the horizontal direction, and a plurality of wirings. A metal sintered body 12 embedded in each of the substrate regions and provided to be unevenly distributed in the vertical direction in each of the plurality of wiring substrate regions, and the upper end in the vertical direction of the plurality of wiring substrate regions A distance L11 from the sintered metal body 12 provided in the wiring board region disposed in the upper area to the upper side of the mother substrate 11 is provided in the wiring board region disposed at the lower end in the vertical direction among the plurality of wiring board regions. This is equal to the distance L12 from the sintered metal body 12 to the lower side of the mother board 11. With such a configuration, a region in which the multi-cavity wiring board is warped or convex can be positioned at the center of the multi-cavity wiring board.

  In the case where the size of the metal sintered body 12 is different between the upper surface side and the lower surface side of the multi-piece wiring substrate as in the example shown in FIG. The distance L11 from the metal sintered body 12 to the lower side of the mother board 11 is L11 = L12, and the distance L13 from the metal sintered body 12 to the upper side of the mother board 11 on the lower surface side and the metal firing The distance L14 from the bonded body 12 to the lower side of the mother board 11 is L13 = L14.

The firing process consists of removing organic components and sintering ceramic and metal powders. The organic component is removed by heating the molded body in a temperature range of about 100 to 1000 ° C. to decompose and volatilize the organic component. The sintering temperature varies depending on the ceramic composition and metal composition, and is performed within a range of about 800 to 1600 ° C. In addition, the firing atmosphere varies depending on the ceramic powder and the conductor material, and is performed in the air, in a reducing atmosphere, or in a non-oxidizing atmosphere, etc. Even if water or the like is included in the atmosphere in order to effectively remove organic components. Good.

  The wiring board is manufactured by dividing the multi-cavity wiring board along the boundary line 1c between the wiring board regions 1a or the boundary line 1c between the wiring substrate region 1a and the dummy region 1b. As a method of dividing a multi-piece wiring board along the boundary line 1c between the wiring board areas 1a or the boundary line 1c between the wiring board area 1a and the dummy area 1b, a dividing groove 1d is formed on the boundary line 1c. In addition, a method of bending and dividing along the dividing groove 1d, a method of cutting along the boundary line 1c by a slicing method, or the like can be used. The dividing grooves 1d are formed by pressing the cutter blade against the molded body before firing, or by cutting it with a slicing device to be smaller than the thickness of the molded body, or by using a slicing device on the multi-piece wiring board after firing. It can be formed by cutting smaller than the thickness of the individual wiring board.

The exposed surface of the wiring conductor 13 in which the wiring conductor pattern 3 is sintered is coated with a plating layer by an electrolytic plating method or an electroless plating method. As a result, it is possible to firmly fix the wiring conductor 13 and the electronic component, the bonding between the wiring conductor 13 and the wiring conductor of the external circuit board, and the bonding between the wiring conductor 13 and the bonding wire. The plating layer is made of a metal excellent in corrosion resistance such as nickel or gold, a metal excellent in reflectivity such as silver, or a metal excellent in heat dissipation such as copper. For example, a nickel plating layer having a thickness of about 1 to 10 μm and a gold plating layer having a thickness of about 0.1 to 3 μm are sequentially deposited. Also, for example, when a light emitting element is mounted as the electronic component 17, if a silver plating layer is further deposited on the surface of the gold plating layer, the light emitted from the light emitting element when the light emitting device is used Reflects well. Further, if a copper plating layer is deposited between the wiring conductor 13 and the nickel plating layer in a region where the electronic component 17 is mounted in a plan view, a wiring board having excellent heat dissipation can be obtained.

  Such a multi-cavity wiring board may be provided with a recess for storing electronic components in the wiring board region 1a on one main surface of the multi-cavity wiring board. The concave portion can be formed by laminating the ceramic green sheet 1 in which the through hole for the concave portion is formed by, for example, a die or punching method by punching, and the ceramic green sheet 1 in which the through hole serving as the bottom surface of the concave portion is not formed. . Further, the concave portions may have a plurality of steps, or may be formed on both main surfaces of the multi-cavity wiring board.

  In addition, the multi-piece wiring board has a plurality of wiring board regions 1a arranged in at least one of the vertical and horizontal directions. Such an arrangement of the wiring board area 1a is set in accordance with the size of the multi-piece wiring board or the wiring board area 1a, the arrangement of the electronic components or wiring conductors 13 mounted on the wiring board area 1a, and the like.

  Further, a dummy region 1b may be arranged between the wiring board regions 1a. In such a case, it is effective to provide asymmetrical cutout holes on the left and right or top and bottom of the wiring board region 1a arranged adjacent to each other in plan view.

  Here, the example shown in FIG. 6 shows a case where the electronic component 17 is a wire bonding type semiconductor element. After the semiconductor element is fixed to the wiring board region 1a with a bonding material, the bonding component 18 is bonded. The electrode of the semiconductor element and the wiring conductor 13 are electrically connected via a wire.

  Further, when the electronic component 17 is a flip chip type semiconductor element, it is connected to the electrode of the semiconductor element via a bonding material such as a solder bump, a gold bump, or a conductive resin (anisotropic conductive resin, etc.). The wiring conductor 13 can be electrically and mechanically connected and joined. In such a case, an underfill may be injected between the electronic component 17 and the wiring substrate after the electronic component 17 is bonded to each wiring board region 1a with a bonding material.

  Since the molded body of this embodiment has the above-described configuration, when the multi-cavity wiring board is warped when the molded body is baked to produce the multi-cavity wiring board, the most concave of the multi-cavity wiring board is formed. Multiple areas or the most convex areas can be placed in the center in the longitudinal direction (y-axis direction) of the wiring board.

  Note that, as in the example shown in FIG. 6, when the metal sintered bodies 12 are arranged at equal intervals, it is effective to increase the efficiency of mounting electronic components on the wiring board region 1 a of the multi-piece wiring board. is there.

(Second Embodiment)
Next, a molded body according to a second embodiment of the present invention will be described with reference to FIG.

  In the molded body according to the second embodiment of the present invention, a portion different from the molded body according to the first embodiment described above is formed at the upper end in the vertical direction of the plurality of wiring board regions 1a as in the example shown in FIG. The distance from the center of the smallest virtual circle 4 among the virtual circles 4 surrounding the plurality of metal bodies 2 provided in the arranged wiring board region 1a to the upper side of the ceramic green sheet 1 is within the plurality of wiring substrate regions 1a. This is a point equal to the distance from the center of the smallest virtual circle 4 to the lower side of the ceramic green sheet 1 among the virtual circles surrounding the plurality of metal bodies 2 provided in the wiring board region 1 a arranged at the lower end in the vertical direction. About another structure, it is the same as that of the molded object by the above-mentioned 1st Embodiment. The virtual circle 4 is an area set based on the metal body 2 and is indicated by a broken line in FIG.

  Also in the molded body of this embodiment, when the multi-cavity wiring board is warped when the molded body is fired to produce the multi-cavity wiring board, the most recessed area or the most convex of the multi-cavity wiring board. A large number of the regions thus obtained can be positioned in the center in the vertical direction (y-axis direction) of the wiring board.

The smallest virtual circle 4 is the smallest virtual circle that can be drawn surrounding the plurality of metal bodies 2 provided in the wiring board region 1a in plan view. Such a minimum virtual circle 4 is a circle drawn in contact with at least two of the plurality of metal bodies 2. In the example illustrated in FIG. 7, the virtual lines 4 are arranged symmetrically with respect to the virtual straight line (CC line), but the smallest virtual circles 4 may be arranged at equal intervals in the vertical direction.

  Further, in the multi-cavity wiring board according to the second embodiment, the portion different from the multi-cavity wiring board of the first embodiment described above is a portion of the plurality of wiring board regions 1a as in the example shown in FIG. The distance from the center of the smallest virtual circle 4 to the upper side of the mother board among the virtual circles surrounding the plurality of sintered metal bodies 12 provided in the wiring board region 1a arranged at the upper end in the vertical direction is a plurality of wiring boards. The distance from the center of the smallest virtual circle 4 to the lower side of the mother substrate 11 among the virtual circles surrounding the plurality of sintered metal bodies 12 provided in the wiring board region 1a arranged at the lower end in the vertical direction in the region 1a. It is an equal point. Other configurations are the same as those of the multi-cavity wiring board according to the first embodiment.

  Also in the multi-cavity wiring board of the present embodiment, a region where the multi-cavity wiring board is warped or convex can be positioned in the center in the vertical direction (y-axis direction) of the multi-cavity wiring board. . In addition, when the minimum virtual circles 4 are arranged at equal intervals in the same direction as in the example shown in FIG. 8, the efficiency of mounting electronic components on the wiring board region 1a of the multi-cavity wiring board is increased. It is effective for.

  In addition, since the multi-piece wiring board of this embodiment can reduce each of the plurality of metal sintered bodies 12 in a plan view as compared with the case where one metal sintered body 12 is disposed, This is effective in increasing the degree of freedom of arrangement and suppressing the deformation of the multi-piece wiring board due to the bias of the wiring conductor 13.

  In addition, this invention is not limited to the example of said embodiment, A various change is possible. For example, at the boundary of the wiring board region 1a, when a multi-cavity wiring board is divided, a hole that becomes a groove is formed, and a conductor is formed on the inner surface of the hole so that the multi-cavity wiring board is divided, so-called A castellation conductor may be formed.

  Further, as in the example shown in FIG. 4, a metal frame pattern 4 surrounding the wiring conductor pattern 3 may be arranged on the outer peripheral portion of each wiring board region 1 a. The metal frame pattern 4 can be manufactured using the same material as the wiring conductor pattern 3. When such a metal frame pattern 4 is sintered, a metal frame 14 like the example shown in FIG. 6 can be formed. The metal frame 14 is made of the same material as the wiring conductor 13 and is a resin fixing portion when the electronic component 17 is resin-molded, or a reflection that reflects the light of the light emitting device when the light emitting device is mounted as the electronic component 17. Can be used as a layer. If a silver plating layer is applied to the surface of the metal frame 14, light emitted from the light emitting element 17 in the side surface direction can be favorably reflected.

  When the electronic component 17 is a light emitting element, as shown in the example shown in FIG. 6, if the sintered metal body 12 is made larger than the electronic component 17 in plan view, the heat generated by the light emitting element is generated. This is preferable because heat can be dissipated over the entire surface of the sintered metal body 12.

  Further, as in the example shown in FIG. 1 or FIG. 3, the metal body 2 may be exposed on at least one of the upper surface or the lower surface of the molded body. Use of such a molded body is effective in improving the heat dissipation of a wiring board obtained by firing and dividing a multi-piece wiring board.

  Further, as in the examples shown in FIGS. 2 and 4 to 6, the metal body 2 may be embedded in the ceramic green sheet 1 without being exposed on the upper surface and the lower surface of the molded body. When an electronic device is formed by using a wiring board obtained by dividing a multi-piece wiring board obtained by firing such a molded body, a surface electrode formed on the upper surface or the lower surface of the wiring board is interposed through a metal sintered body 12. A short circuit can be prevented. Therefore, the surface electrode can be enlarged in plan view.

  A heat radiator may be disposed on the lower surface of the wiring board region 1a of the mother board 11. Such a radiator improves heat dissipation by bonding or abutting between the radiator and the external circuit board when an electronic device using a wiring board obtained by dividing a multi-piece wiring board is mounted on the external circuit board. be able to.

  In addition, the sintered metal body 12 preferably has a rectangular shape with corners arcuate in plan view. In the case of the rectangular electronic component 17, the size of the metal sintered body 12 can be reduced without reducing the area overlapping the electronic component in plan view in the wiring board region 1a. Short circuit with the electrode can be reduced.

  Further, when it is desired to partially increase the heat dissipation property, the electronic component 17 may be disposed so that the portion where the heat dissipation property is to be increased in plan view and the metal sintered body 12 overlap. For example, if the electronic component 17 is an image sensor, the metal sintered body 12 may be disposed so as to overlap a signal processing circuit portion such as a DSP (Digital Signal Processor) provided in the image sensor. Heat generated in the signal processing circuit is easily transferred to the sintered metal body 12, and heat is less likely to be transferred to the light receiving part, so that the light receiving part of the image sensor can be prevented from being distorted by heat and power consumption can be reduced. Can be reduced.

  In the multi-cavity wiring board of the second embodiment, the plurality of metal sintered bodies 12 may be connected to each other through a metal member inside the mother board 1. In the case where electronic components are mounted on a wiring board obtained by dividing such a multi-piece wiring board, when the metal sintered body 12 is used as a heat sink, heat generated in the electronic parts is generated by a plurality of metal sintered bodies 12. It is easy to dissipate heat evenly.

DESCRIPTION OF SYMBOLS 1 ... Ceramic green sheet 1a ... Wiring board area | region 1b ... Dummy area | region 1c ... Boundary line 1d of the wiring board area | region 1a ... Dividing groove 2 ... Metal body 3 ... Wiring conductor pattern 4 ... Minimum virtual circle
11 ... Mother board
12 ... Metal sintered body
13 ... Wiring conductor
14 ... Metal frame
17 ... Electronic components
18 ・ ・ ・ ・ Connection member

Claims (7)

  It has a rectangular shape in plan view, and is embedded in each of the plurality of ceramic green sheets including a plurality of wiring board regions arranged in the vertical and horizontal directions, and each of the plurality of wiring board regions, Each of the plurality of wiring board regions, and a metal body that is unevenly distributed in the vertical direction, and the wiring board region disposed at an upper end in the vertical direction among the plurality of wiring board regions. The distance from the provided metal body to the upper side of the ceramic green sheet is from the metal body provided in the wiring board region disposed at the lower end in the vertical direction among the plurality of wiring board regions to the ceramic green. A molded body characterized by being equal to the distance to the lower side of the sheet. It has a rectangular shape in plan view, and is embedded in each of the plurality of ceramic green sheets including a plurality of wiring board regions arranged in the vertical and horizontal directions, and each of the plurality of wiring board regions, A plurality of metal bodies provided unevenly in the vertical direction in each of the plurality of wiring board regions,
From the center of the smallest virtual circle to the upper side of the ceramic green sheet among the virtual circles surrounding the plurality of metal bodies provided in the wiring substrate region arranged at the upper end in the vertical direction among the plurality of wiring substrate regions Of the ceramic green from the center of the smallest virtual circle among the virtual circles surrounding the plurality of metal bodies provided in the wiring substrate region disposed at the lower end in the vertical direction among the plurality of wiring substrate regions A molded body characterized by being equal to the distance to the lower side of the sheet.   3. The metal body according to claim 1, wherein the metal bodies are arranged symmetrically with respect to a virtual straight line extending in the lateral direction through the center of the ceramic green sheet in plan view. Molded body.   The molded body according to claim 1, wherein the metal bodies are arranged at equal intervals in the longitudinal direction.   In the plurality of wiring board regions arranged adjacent to each other in the vertical direction from the wiring board region arranged at the upper end in the vertical direction to the wiring board region arranged at the lower end in plan view, the metal body is The molded body according to claim 1, wherein the molded body is arranged symmetrically with respect to a boundary between a plurality of wiring board regions.   The substrate has a rectangular shape in plan view, and is embedded in each of the plurality of wiring board regions and a mother board that includes a plurality of wiring board regions arranged in the vertical direction and the horizontal direction. Each of the wiring board regions is provided with a metal sintered body that is unevenly distributed in the vertical direction, and is provided in the wiring board region arranged at the upper end in the vertical direction among the plurality of wiring board regions. The distance from the metal sintered body to the upper side of the mother board is from the metal sintered body provided in the wiring board region disposed at the lower end in the vertical direction among the plurality of wiring board regions. A multi-piece wiring board characterized by being equal to the distance to the lower side of the mother board. The substrate has a rectangular shape in plan view, and is embedded in each of the plurality of wiring board regions and a mother board that includes a plurality of wiring board regions arranged in the vertical direction and the horizontal direction. A plurality of metal sintered bodies provided unevenly in the longitudinal direction in each of the wiring board regions,
The upper side of the mother substrate from the center of the smallest virtual circle among the virtual circles surrounding the plurality of sintered metal bodies provided in the wiring substrate region disposed at the upper end in the vertical direction among the plurality of wiring substrate regions The distance from the center of the smallest virtual circle among the virtual circles surrounding the plurality of metal sintered bodies provided in the wiring substrate region disposed at the lower end in the vertical direction among the plurality of wiring substrate regions A multi-piece wiring board characterized by being equal to a distance to a lower side of the mother board.

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