JP5209856B2 - Wiring board - Google Patents

Description

  The present invention provides a wiring comprising: a heat radiating member for mounting an electronic component such as a light emitting element or an IC chip on an upper element mounting surface; and a substrate body made of an insulating material that penetrates and fixes a column portion of the heat radiating member. Regarding the substrate.

In order to easily obtain a high-intensity light amount, an LED element is mounted on a heat dissipation member that penetrates a multilayer substrate made of ceramic, and an inclined surface for light reflection is provided on the upper surface of the multilayer substrate surrounding the LED element. A light emitting device in which a package is formed and a mold resin for sealing the LED element inside the package is filled and a method for manufacturing the light emitting device have been proposed (for example, see Patent Document 1).
In order to effectively release the heat generated by the LED element, the heat dissipation member used in the light emitting device has an LED element mounted thereon and an upper portion having a small cross-sectional area exposed on the upper surface of the multilayer substrate, and a back surface of the multilayer substrate. In general, the lower portion having a large cross-sectional area exposed in the shape of a rectangular or circular shape that is similar to each other in a plan view.

JP 2006-32804 A (pages 1 to 18, FIGS. 1 and 4)

  However, when the heat radiating member of the above form is fixed to the wiring board made of ceramic or the like, a considerable percentage of the area is occupied on the back surface of the wiring board by the bottom surface of the lower part having a large cross sectional area of the heat radiating member. The As a result, the arrangement quantity and position of pads used for electrical connection with a mother board such as a printed circuit board on which such a wiring board is mounted are limited, and there is a problem that electrical connection with the mother board becomes insufficient. In particular, the use of the heat radiating member of the above-described form has been an obstacle in meeting the demands for reducing the size of the wiring board and increasing the number of pads.

  The present invention solves the problems described in the background art, and uses a heat radiating member having an element mounting surface at the upper end through a substrate body made of an insulating material, and the number of pads to be formed on the back surface of the substrate body. It is an object of the present invention to provide a wiring board that can sufficiently ensure the above.

Means for Solving the Problems and Effects of the Invention

In order to solve the above-mentioned problems, the present invention is similar to each other in plan view in a heat dissipating member between a column part having a small cross-sectional area having an element mounting surface at the upper end and a horizontal part having a large cross-sectional area extending from the side surface. The idea is that the bottom of the horizontal portion does not excessively occupy the back surface of the wiring board.
That is, the wiring board of the present invention (Claim 1) is made of an insulating material, and a substrate body having a front surface and a back surface that are rectangular in plan view, and a through-hole penetrating between the surface and the back surface of the substrate body, A heat radiation member having a pillar portion inserted into the through-hole, a plurality of horizontal portions extending from the side surfaces of the pillar portion in different directions and fixed to the substrate body, and the heat radiation on the back surface of the substrate body A pad formed at a position where there is no member, and the substrate body has a plurality of depressions that communicate with one end of the through hole and open in different directions on the back surface of the substrate body, and The member includes a rectangular or circular element mounting surface at a top end in a plan view, and the column part having a quadrangular column or a cylindrical shape, and extends from a side surface of the column part in a direction symmetrical to the central axis of the column part. The above A horizontal portion of, Tona is, the plural of the horizontal portion is inserted and fixed individually to the plurality of recesses, and the element mounting surface and a horizontal portion positioned at the upper end of the column portion, similar to each other in a plan view It is not a form.

According to this, in addition to the portion occupied by the bottom surfaces of the column portions and the plurality of horizontal portions in the heat radiating member, a portion having a considerable area remains on the back surface of the substrate body. For example, when the front and back surfaces of the substrate body are rectangular (square and rectangular) in plan view, and a pair (plurality) of horizontal portions of the heat dissipating member are linearly connected to each other, the column portion and this are symmetrical A back surface having a considerable area remains on both sides of the band-shaped metal portion formed of the bottom surfaces of the pair of horizontal portions located at the positions. For this reason, since the required number of pads can be easily formed on the back surface of the board body, it is possible to sufficiently ensure conduction with a mother board such as a printed board on which the wiring board is to be mounted. Accordingly, the wiring board can be easily adapted to miniaturization and an increase in the number of pads.
Further, for example, when the pillar portion of the heat dissipation member is a square pillar including an element mounting surface that is rectangular in plan view, a pair of horizontal portions extend linearly from two opposing side surfaces of the pillar portion. Alternatively, three or four horizontal portions extend from any three side surfaces or from all side surfaces in different directions of 90 degrees from each other. Further, when the pillar portion has a cylindrical shape including an element mounting surface having a circular plan view, a plurality of horizontal portions extend from the side surface (circumferential surface) of the pillar portion in the same manner as described above. For this reason, for example, in the case of a form in which the bottom surfaces of the column portion and the four horizontal portions that are exposed in the substantially central portion of the back surface of the substrate body that is rectangular in plan view extend to the central portion of each side surface of the substrate body, In the vicinity of each corner, a portion without the horizontal portion remains in a considerable area. Therefore, it is possible to provide a wiring board in which a required number of pads are easily formed for each corner portion on the back surface of the four places.
In addition, since the plurality of horizontal portions are individually inserted and fixed in the plurality of recesses, the heat radiation member can be firmly fixed to the substrate body, and the bottom surface of the plurality of horizontal portions and column portions is not located in the substrate body. A wiring board having a required number of pads formed on the back surface of a considerable area can be obtained .

The insulating material includes a high-temperature fired ceramic such as alumina, a low-temperature fired ceramic such as glass-ceramic, or an epoxy resin.
Further, the heat radiating member is made of Cu, Al having high thermal conductivity, or an alloy based on these, and has a form in which a plurality of the horizontal portions extend along different directions from the side surface of the column portion. doing.
Furthermore, the element mounting surface located at the upper end of the column portion in the heat dissipation member is substantially flush with the surface of the substrate body. Alternatively, in the form in which the substrate body has a cavity opened on the surface thereof, the bottom surface of the cavity is substantially flush with the bottom surface of the cavity, and the surface of the substrate body is the surface.
Further, the fixing between the substrate body and the heat dissipation member is between the ceiling surface and side surfaces of the plurality of depressions in the substrate body and the upper surfaces and side surfaces of the plurality of horizontal portions in the heat dissipation member, or between the back surface of the substrate body and the heat dissipation member. For example, brazing or bonding is performed between the upper surface of the horizontal portion.

Further, according to the present invention, the width of each horizontal portion of the heat radiating member is the same as or shorter than the length of each side surface of the column portion in the column portion having a rectangular cross section, and the cross section is circular. In the column part, a wiring board (Claim 2 ) having the same diameter as the column part or smaller than the diameter is also included.

Incidentally, the pillar portion of the discharge heat member may cylindrical, three from the side of such a column portion and form by extending the horizontal portion in a direction shifted 120 degrees from one another, of the substrate main body back side also the three A configuration in which three recesses for inserting and fixing the horizontal portion are provided, or three horizontal portions are extended in three directions of a substantially T shape in plan view, and these three horizontal portions are inserted and fixed 3 It is also possible to adopt a form in which two depressions are provided in a substantially T shape.

In the following, the best mode for carrying out the present invention will be described.
1 is a plan view showing a wiring board 1 according to an embodiment of the present invention, FIG. 2 is a vertical sectional view taken along the line XX in FIG. 1, and FIG. FIG. 4 is an exploded perspective view of the wiring board 1 at a viewing angle viewed obliquely from below, and FIG. 5 is a bottom view of the wiring board 1.
As shown in FIGS. 1 to 5, the wiring substrate 1 includes a substantially plate-shaped substrate body 2 having a front surface 3 and a rear surface 4 that are square (rectangular) in plan view, and a front surface 3 and a rear surface 4 of the substrate body 2. And a heat dissipating member 10 that penetrates and adheres between the two.
The substrate body 2 is a multilayer substrate in which ceramic layers s1 to s3 made of alumina are integrally laminated, and a through-hole 5 having a square shape in plan view passes between substantially the center portions of the front surface 3 and the back surface 4, and this is applied. One end communicates with two opposite sides of the through-hole 5 individually, and has a pair (a plurality) of recesses 6 having a rectangular parallelepiped shape opened on the back surface 4 side.

  As shown in FIGS. 1 and 2, a plurality of surface pads 7 made of W or Mo are formed around the through holes 5 on the surface 3 of the substrate body 2. As shown in FIGS. 3 to 5, a plurality of back surface pads (pads) 8 made of W or the like are formed in a pair of rectangular portions sandwiching the through holes 5 and the recesses 6 and 6 in the back surface 4 of the substrate body 2. However, it is formed in a lattice shape vertically and horizontally. A via conductor 9 connected to the front surface pad 7 passes through the uppermost ceramic layer s3, and a via conductor 9 connected to the back surface pad 8 passes through the lowermost ceramic layer s1. The via conductor 9 can be conducted through a wiring layer (not shown) formed in a predetermined pattern between the ceramic layers s1 to s3 and a via conductor (not shown) penetrating the middle ceramic layer s2.

On the other hand, the heat dissipating member 10 is made of, for example, a Cu alloy, and as shown in the exploded perspective view of FIG. 4, the column portion 12 presenting a square column having a square (rectangular) element mounting surface 11 at the upper end in plan view, and the like. It integrally has a pair of horizontal portions 14 extending linearly in different directions so as to be separated from the bottom surface 16 side of the side surface 13 of the column portion 12. In addition, the horizontal cross section of the column part 12 is substantially the same size as the cross section of the through hole 5. Further, the bottom surface 16 is used in common for both the column portion 12 and the horizontal portion 14 (the same applies hereinafter).
In the heat dissipation member 10, the upper surface and each side surface of the pair of horizontal portions 14 are coated with a brazing material or an adhesive in advance, and then the column portion 12 is attached to the substrate body 2 as shown in the vertical sectional views of FIGS. While inserting into the through-hole 5 from the back surface 4 side, a pair of horizontal part 14 is inserted and fixed to each hollow 6 separately. At this time, the element mounting surface 11 of the pillar portion 12 is substantially flush with the surface 3 of the substrate body 2, and the bottom surface 16 of the pillar portion 12 and the bottom surface 16 of each horizontal portion 14 are substantially flush with the back surface 4 of the substrate body 2. Become one.

An electronic component such as an IC chip (not shown) or a light emitting element such as an LED element is mounted on the element mounting surface 11 of the column portion 12 of the heat radiating member 10 via a brazing material or a conductive adhesive. Such electronic components are electrically connected to the surface pad 7 through bonding wires.
On the other hand, as shown in the bottom view of FIG. 5, on the back surface 4 of the substrate body 2, the bottom surface 16 of the column portion 12 of the heat radiating member 10 is exposed at the center portion, and the bottom surfaces of the pair of horizontal portions 14 on the left and right sides. 16 extends. A plurality of back surface pads 8 are formed in a lattice pattern on each of the back surface 4 portions that form a pair of upper and lower rectangles in FIG. 5 with the pillar portion 12 and the bottom surface 16 of the pair of horizontal portions 14 sandwiched therebetween.
The element mounting surface 11, the bottom surface 16, the front surface pad 7, and the back surface pad 8 of the heat radiating member 10 are covered with a Ni plating film and an Au plating film (not shown).

The wiring board 1 as described above was manufactured as follows.
A ceramic slurry was prepared by mixing raw materials composed of alumina powder particles, a resin binder, a plasticizer, a solvent, and the like in advance. The ceramic slurry was subjected to a doctor blade method to form three-layer green sheets having a square shape in plan view and different thicknesses.
Next, a through hole having a square cross section was formed by punching with a punch and a die receiving hole in the two green sheets of the three layers. For the remaining one green sheet, through holes having a rectangular cross-section having a larger vertical and horizontal dimension than the two through holes were formed by the same punching process.
Next, a required number of via holes are formed around each through hole in the three-layer green sheet in which the above through holes are formed, and a conductive paste containing W or Mo powder is filled therein to fill the vias. A conductor 9 was formed.

Further, a conductive paste was screen-printed with a predetermined pattern on at least one of the front and back surfaces of each green sheet to form a wiring layer, a front surface pad 7 and a back surface pad 8 having a predetermined pattern.
Next, the remaining two layers of green sheets were laminated and pressure-bonded on the upper surface of the green sheet having a rectangular through-hole so that the through-holes communicated concentrically to form a green sheet laminate. The green sheet laminate was heated and fired at a predetermined temperature range. As a result, a substrate body 2 made of ceramic layers c1 to c3 and having the front surface 3, the back surface 4, the through hole 5, and a pair of depressions 6 with one end communicating with the back surface 4 side of the through hole 5 was obtained. .

On the other hand, a thick plate-like material made of a Cu alloy is press-molded, for example, and extended along a direction facing the column portion 12 having the element mounting surface 13 having a square top view on the upper end and the side surface 13. The heat radiating member 10 having a pair of horizontal portions 14 is formed.
Next, as shown by the arrows in FIG. 4, the column portions 12 of the heat radiating member 10 in which Ag brazing sheets (not shown) are arranged on the upper surface and each side surface of the pair of horizontal portions 14 are formed in the through holes 5 of the substrate body 2. The horizontal portion 14 was inserted into the recess 6 of the substrate body 2 while being inserted. At this time, the element mounting surface 13 and the surface 3 of the substrate body 2, the bottom surface 16 of the column portion 12 and each horizontal portion 14, and the back surface 4 of the substrate body 2 were substantially flush.
Further, the substrate body 2 and the heat radiating member 10 were heated to about 700 to 900 ° C. to melt the Ag wax, and the substrate body 2 and the heat radiating member 10 were fixed. In addition, when the heat radiating member 10 consists of Al alloy, it adheres to the board | substrate body 2 with an adhesive agent.

Finally, Ni electroplating is applied to the element mounting surface 11 of the column portion 12, the bottom surface 16 of the column portion 12 and each horizontal portion 14, the front surface pad 7, and the back surface pad 8 in the heat radiating member 10 fixed to the substrate body 2. Au electrolytic plating was sequentially performed to coat these plating films (none of which are shown).
As a result, the wiring board 1 shown in FIGS. 1 to 3 and FIG. 5 was obtained.
According to the wiring board 1 as described above, the back surface 4 of the substrate body 2 has a back surface of a considerable area on both sides of the belt-shaped portion occupied by the bottom surface 16 of the column portion 12 and the pair of horizontal portions 14 in the heat radiating member 10. Part (4) remains. For this reason, since the required number of back surface pads 8 can be easily formed on the back surface 4 of the substrate body 2, it is possible to sufficiently ensure electrical connection between the wiring substrate 1 and a mother board such as a printed circuit board. Therefore, the wiring board 1 can be easily adapted to miniaturization and an increase in the number of pads.

FIG. 6 is an exploded perspective view showing a wiring board 1a which is an application form of the wiring board 1, and FIG. 7 is a bottom view of the wiring board 1a.
As shown in FIGS. 6 and 7, the wiring board 1 a also penetrates between the same board main body 2 a having a front surface 3 and a rear surface 4 that are square in plan view, and between the front surface 3 and the rear surface 4 of the board main body 2 a. And a heat dissipating member 10a fixed thereto.
The substrate body 2a is a multilayer substrate similar to that described above, and the through hole 5 similar to the above penetrates between substantially the center of the front surface 3 and the back surface 4, and one end is provided on each side of the through hole 5 on the back surface 4 side. It has four recesses 6 that communicate with each other and open in the direction orthogonal to each other and open to the back surface 4 side. A surface pad 7 similar to that described above is formed around the through hole 5 in the surface 3 of the substrate body 2a.

Further, as shown in FIGS. 6 and 7, a plurality of back surface pads 8 are vertically and vertically disposed at four portions exhibiting a square near each corner sandwiched between four recesses 6 on the back surface 4 of the substrate body 2a. It is formed in a lattice form on the side. The front surface pad 7 and the rear surface pad 8 can be electrically connected to each other through the via conductor 9 similar to the above.
On the other hand, as shown in FIG. 6, the heat radiating member 10 a has the same column part 12 having the element mounting surface 11 at the upper end and a direction orthogonal to the cross so as to be separated from each side surface 13 of the column part 12. It has four horizontal portions 14 that extend. That is, the four horizontal portions 14 extend in a direction symmetric with respect to the central axis of the column portion 12.
Similarly to the above, the heat radiating member 10a is coated with a brazing material or an adhesive, and then, as shown by an arrow in FIG. 6, the column portion 12 is inserted into the through hole 5 from the back surface 4 side of the substrate body 2a. The horizontal part 14 is inserted and fixed individually in each recess 6. At this time, the element mounting surface 11 is substantially flush with the surface 3 of the substrate body 2a, and the bottom surface 16 of the column portion 12 and each horizontal portion 14 is substantially flush with the back surface 4 of the substrate body 2a.

In addition, the same electronic component as described above is mounted on the element mounting surface 11 of the column portion 12 in the heat radiating member 10a, and the electronic component is electrically connected to the surface pad 7 through a bonding wire.
On the other hand, as shown in the bottom view of FIG. 7, on the back surface 4 of the substrate body 2a, the bottom surface 16 of the column portion 12 of the heat radiating member 10a is exposed at the center, and the bottom surfaces of the four horizontal portions 14 on the left, right, and top 16 extends. A plurality of back surface pads 8 are formed in a grid pattern on each back surface (4) portion that forms a square near each corner with each horizontal portion 14 interposed therebetween. The element mounting surface 11, bottom surface 16, front and back pads 7, 8, etc. of the heat radiating member 10 are covered with the same Ni plating film and Au plating film as described above.
According to the wiring board 1a as described above, since the heat dissipation member 10a has the four horizontal portions 14, heat generated by electronic components mounted on the element mounting surface 11 can be efficiently dissipated. In addition, since the required number of back surface pads 8 are formed in the vicinity of each corner on the back surface 4 of the substrate main body 2a, it is possible to sufficiently ensure conduction with the mother board.

8 is a perspective view transparently showing the wiring board 20 in a different form, FIG. 9 is a perspective view showing a heat radiation member 30 used in the wiring board 20, and FIG. 10 is a bottom view of the wiring board 20.
As shown in FIGS. 8 and 10, the wiring substrate 20 includes a substantially plate-shaped substrate body 22 having a front surface 23 and a back surface 24 that are square (rectangular) in plan view, and a front surface 23 and a back surface 24 of the substrate body 22. And a heat dissipating member 30 that is penetrated and fixed between. The substrate body 22 is a multilayer substrate similar to that described above, and a through hole 25 having a circular cross section passes between substantially the center portion of the front surface 23 and the back surface 24, and one end communicates with the back surface 24 side of the through hole 25. A pair of depressions 26 are formed in straight (different) directions that are separated from each other. A plurality of surface pads 27 similar to those described above are formed at substantially equal intervals around the through hole 25 on the surface 23 of the substrate body 22.

On the other hand, the heat dissipating member 30 is also made of a Cu alloy or the like, and as shown in FIG. 9, as shown in FIG. And a pair of horizontal portions 34 that extend linearly in different directions so as to be separated from each other. The horizontal cross section of the column part 32 is substantially the same size as the cross section of the through hole 25.
The heat radiating member 30 previously covers the upper surface and each side surface of the pair of horizontal portions 34 with a brazing material or an adhesive, and similarly inserts the column portion 32 into the through hole 25 from the back surface 24 side of the substrate body 22. At the same time, the pair of horizontal portions 24 are individually inserted and fixed in the recesses 26. At this time, the element mounting surface 31 is substantially flush with the surface 23 of the substrate main body 22, and the bottom surface 36 of the column portion 32 and each horizontal portion 34 is substantially flush with the back surface 24 of the substrate main body 22.

Furthermore, as shown in the bottom view of FIG. 10, on the back surface 24 of the substrate body 22, the bottom surface 36 of the column portion 32 of the heat radiating member 30 is exposed at the center, and the bottom surfaces of the pair of horizontal portions 34 on the left and right sides. 36 extends. A plurality of back surface pads (pads) 28 are formed in a lattice pattern on each back surface (34) portion that forms a pair of upper and lower rectangles in FIG. 10 across the bottom surface 36 of the pillar portion 32 and the pair of horizontal portions 34. Yes.
Similarly to the above, on the element mounting surface 31 of the pillar portion 32 of the heat radiation member 30, electronic components such as IC chips are mounted, and these electronic components are electrically connected to the surface pad 27 via bonding wires. Is done. The element mounting surface 31, the bottom surface 36, the front surface pad 27, and the back surface pad 28 of the heat radiating member 30 are covered with Ni and Au plating films.
The wiring board 20 as described above can be manufactured in the same manner as the wiring board 1 and can provide the same effects.

FIG. 11 is a bottom view of a wiring board 20a which is an application form of the wiring board 20, and the wiring board 20a is also provided between the same board body 22a and the front surface 23 and the back surface 24 of the board body 22a. And a heat dissipating member 30a fixed through. The substrate main body 22a has a through hole 25 similar to the above that penetrates substantially between the center portion of the front surface 23 and the back surface 24, and one end is individually connected to the back surface 24 side of the through hole 25 and extends in directions orthogonal to each other. There are four depressions 26 opened on the back surface 24 side.
In addition, as shown in FIG. 11, a plurality of back surface pads 28 are vertically arranged on the back surface (24) portions of the four places that form squares in the vicinity of each corner sandwiched between four recesses 26 on the back surface 24 of the substrate body 22a. -It is formed in a grid pattern on the side.

Further, similarly to the above, the heat radiating member 30a includes a column portion 32 having the element mounting surface 31, and four horizontal portions 34 extending in a cross-shaped direction so as to be separated from the side surface 33 of the column portion 32. It has one. That is, the four horizontal portions 34 extend in a direction symmetric with respect to the central axis of the column portion 32. Similarly to the above, the heat dissipating member 30a is also inserted into the through holes 25 from the back surface 24 side of the substrate body 22a, and the four horizontal portions 34 are individually inserted into and fixed to the recesses 26.
The wiring board 20a as described above can be manufactured in the same manner as the wiring boards 1 and 20, and can have the same effects as the wiring board 1a.

FIG. 12 is a bottom view of a further different form of the wiring board 40a. The wiring board 40a has a rectangular (rectangular) front surface and a rear surface 44 in plan view, and the front and rear surfaces of the substrate main body 42a. , And a heat radiating member 50a that is fixedly penetrated between the two. The substrate main body 42a has a through-hole 45 having a square or circular cross section between substantially the center between the front surface and the back surface 44. One end of the through-hole 45 communicates with the back surface 44 side of the through-hole 45 and is linearly separated. It has a pair of dents 46 a that extend while opening in the back surface 44. The pair of recesses 46a are located along the short side direction of the back surface 44 of the substrate body 42a, and each corner on the tip side is rounded.
Further, the heat radiating member 50a extends in a linear direction so as to be spaced apart from the square columnar or cylindrical column part 52 having the same element mounting surface at the upper end and the side surface 53 of the column part 52. And a pair of horizontal portions 54 with rounded corners.

Similarly to the heat dissipation member 50a, the column portion 52 is inserted into the through hole 45 of the substrate body 42a, and the horizontal portions 54 are inserted into the recesses 46 and fixed in the same manner as described above.
Furthermore, as shown in FIG. 12, on the back surface 44 of the substrate body 42a, the bottom surface 56 of the column portion 52 of the heat radiating member 50a is exposed at the center, and the bottom surfaces 56 of the pair of horizontal portions 54 extend on both upper and lower sides. I'm out. A plurality of back surface pads (pads) 48 are formed in a grid pattern on each back surface (44) portion that forms a pair of left and right rectangles in FIG. 12 across the bottom surface 56 of the pillar portion 52 and the pair of horizontal portions 54. Yes.
The wiring board 50a as described above can be manufactured in the same manner as the wiring board 1 and can achieve the same effects as the wiring board 1.

FIG. 13 is a bottom view of a wiring board 40b of a different form. The wiring board 40b includes a board body 42b having a front surface and a back surface 44 that are rectangular (rectangular) in plan view, and the front and back surfaces of the board body 42b. , And a heat radiating member 50b that is fixed to pass through. The substrate main body 42b has a through-hole 45 having a square or circular cross section between the front surface and the back surface 44 in FIG. 13 and close to the upper side, and one end communicates with the back surface 44 side of the through-hole 45 individually. It has four depressions 46 and 46 b that extend in a cross shape and open to the back surface 44. In FIG. 13, the upper recess 46 b is formed shorter than the other three recesses 46.
Further, as shown in FIG. 13, the heat radiating member 50b is substantially separated from the square columnar or cylindrical column part 52 having the same element mounting surface at the upper end and the side surface 53 of the column part 52. Four horizontal portions 57 and 58 having different lengths extending in the cross shape are integrally provided.

Three long horizontal portions 57 are inserted into the recess 46, and a short horizontal portion 58 is inserted into the recess 46b, so that the heat radiating member 50b and the substrate body 42b are fixed in the same manner as described above.
Further, as shown in FIG. 13, the bottom surface 56 of the column portion 52 of the heat radiating member 50 b is exposed above the back surface 44 of the substrate body 42 b, and the bottom surfaces 56 of the four horizontal portions 57 and 58 are vertically and horizontally. It is extended. A plurality of back surface pads (pads) 48 are formed in a linear shape or a lattice shape in the vicinity of each corner having a different width on the back surface 44 sandwiched between the bottom surfaces 56 of the horizontal portions 57 and 58.
The wiring board 50b as described above can be manufactured in the same manner as the wiring board 20 and can provide the same effects as the wiring boards 1 and 20.

14 and 15 are vertical sectional views of the wiring board 1b, which is a modified form of the wiring board 1, at a viewing angle perpendicular to each other.
The wiring board 1b is different from the wiring board 1 in that the board body 2b is made of ceramic layers s2 and s3, the back surface 4 is flat and does not have the depressions 6, and the heat radiating member 10 includes each horizontal portion 14. It is to be fixed to the back surface 4 of the substrate body 2b on the top surface of the substrate.
According to the wiring substrate 1b, the bottom surface 16 of the column portion 12 and the pair of horizontal portions 14 of the heat radiating member 10 protrude downward from the back surface 4 of the substrate body 2b. Heat can be efficiently radiated to the outside, and a required number of back surface pads 8 can be formed on the back surface 4 at positions where the heat radiating member 10 is not present. In addition, it is possible to easily secure a solder space between the back pad 8 and the external connection terminal on the mother board side on which the wiring board 1b is to be mounted.
Instead of the heat radiating member 10, the heat radiating member 10 a having four horizontal portions 14 is used, or the substrate body 22 b having the through hole 5 as the through hole 25 having the circular cross section is used, and the heat radiating members 30 and 30 a are formed. It is also possible to use the wiring board 20b to be used.

FIG. 16 is a vertical sectional view showing a wiring board 60 for mounting a light emitting element.
The wiring substrate 60 is fixed in a penetrating manner between a substrate body 62 having a front surface 63, a rear surface 64, and a cavity 67 opening in the front surface 63, and a bottom surface 69 of the cavity 67 and the rear surface 64. The same heat dissipation member 10 as described above is provided.
The substrate body 62 is formed by integrally laminating and firing a ceramic layer s4 having a substantially conical through hole on the ceramic layers s1 to s3 similar to the above and having a side surface 68 inclined so as to spread toward the surface 63 side. It is. As shown in FIG. 16, a through hole 65 having a square cross section passes between the bottom surface 69 and the back surface 64 of the cavity 67 in the substrate body 62, and one end communicates with the through hole 65 on the back surface 64 side. The pair of recesses 66 are formed in a straight line so as to be separated from each other.
The bottom surface 69 of the cavity 67 is the surface of the substrate body in the present invention.

A pair or a plurality of surface pads 7 are formed around the through-hole 65 in the bottom surface 69 of the cavity 67. In addition, a pair or a plurality of the back surface pads 8 are formed at two positions on the back surface 64 of the substrate main body 62 at positions where the heat radiating member 10 is not present (front-rear direction in FIG. 16).
Further, as shown in FIG. 16, the heat radiating member 10 has the pillar portion 12 inserted into the through hole 65 of the substrate body 62, and a pair of horizontal portions 14 previously coated with a brazing material in the same manner as described above. By being individually inserted and heated, the substrate body 62 is fixed.
Furthermore, the element mounting surface 11 of the heat radiating member 10 is substantially flush with the bottom surface 69 of the cavity 67, and a light emitting element (not shown) such as an LED element is mounted in the same manner as described above. Such a light emitting element is also connected to the surface pad 7 via a bonding wire.

FIG. 17 is a vertical sectional view showing a wiring board 60b which is a modification of the wiring board 60. FIG. The wiring board 60b is different from the wiring board 60 in that the board body 62b is made of ceramic layers s2 to s4, the back surface 64 is flat and does not have the depression 66, and the heat radiating member 10 includes each horizontal portion 14. The upper surface of the substrate main body 62b is fixed to the rear surface 64 of the substrate body 62b.
According to the wiring boards 60 and 60b as described above, the required number of back surface pads 8 can be formed in the same manner as described above on the back surfaces 64 of the substrate bodies 62 and 62b without the heat dissipating member 10, and the element mounting surface of the heat dissipating member 10 The light emitted from the light emitting element or the light emitting elements mounted on 11 can be reflected by the side surface 68 of the cavity 67 and emitted to the outside. Moreover, in the wiring board 60b, a solder space can be easily secured between the back pad 8 and the external connection terminal on the mother board side on which the wiring board 60b is to be mounted.
In the wiring boards 60 and 60b, similarly to the above, the heat radiating member 10a is used instead of the heat radiating member 10, or the heat radiating members 30 and 30a are formed by using the through holes 65 of the board body 62b as circular through holes. It is also possible to use it.

The present invention is not limited to the embodiments described above.
The insulating material forming the substrate main body may be a ceramic such as aluminum nitride or mullite, a glass-ceramic which is a kind of low-temperature fired ceramic, or various resins including epoxy.
Further, the column portion and the element mounting surface of the heat radiating member may be rectangular, oval, or elliptical in plan view. In the case of such a column portion, the cross section of the through hole of the substrate body is similar to these. It is possible to mount two or more electronic components and light emitting elements on the element mounting surface such as the rectangle.
Furthermore, the horizontal portion of the heat dissipation member may be substantially semi-oval or semi-elliptical in plan view. In the case of such a column portion, the shape of the recess of the substrate body is similar to these.
In addition, the wiring board of the present invention may be in the form of a multi-piece substrate in which a plurality of wiring boards are arranged vertically and horizontally.

The top view which shows the wiring board of one form in this invention. FIG. 2 is a vertical sectional view taken along line XX in FIG. 1. FIG. 2 is a vertical sectional view taken along the line YY in FIG. 1. The disassembled perspective view by the viewing angle which looked up from the diagonally lower side of the said wiring board. The bottom view of the said wiring board. The disassembled perspective view which shows the wiring board which is an application form of the said wiring board. The bottom view of the said wiring board. The perspective view which shows perspectively the wiring board of a different form. The perspective view which shows the heat radiating member used for the said wiring board. The bottom view of the said wiring board. The bottom view of the wiring board which is an application form of the said wiring board. Furthermore, the bottom view of the wiring board of a different form. The bottom view of the wiring board of another form. The vertical sectional view of the wiring board which is a deformation | transformation form of the said wiring board. FIG. 15 is a vertical sectional view of the wiring board at a viewing angle orthogonal to FIG. 14. The vertical sectional view which shows the wiring board for light emitting element mounting in this invention. The vertical sectional view showing the modification of the above-mentioned wiring board.

Explanation of symbols

1, 1a, 1b, 20, 20a, 40a, 40b, 60, 60b ... Wiring board 2, 2a, 2b, 22, 22a, 42a, 42b, 62, 62b ... Board body 3, 23, 63 ... …………………………………… Front side 4,24,44,64 ………………………………………… Back side 5, 25, 45, 65 ………… ……………………………… Through hole 6, 26, 46, 46a, 46b, 66 …………………… Recess 8, 28, 48 …………………………… …………………… Back side pad (pad)
10, 10a, 30, 30a, 50a, 50b ............... Heat dissipation member 11, 31 ......................................................... ……………………………… Element mounting surface 12, 32, 52 ……………………………………………… Pillar 13, 33, 53 ……………………………………………… Side 14, 34, 54, 57,58 ……………………………… Horizontal part

Claims (2)

A substrate body made of an insulating material and having a rectangular front surface and a back surface in plan view;
A through hole penetrating between the front surface and the back surface of the substrate body,
A heat dissipation member having a plurality of horizontal portions that extend along different directions from the side portions of the pillar portions inserted into the through holes and are fixed to the substrate body;
A pad formed at a position without the heat dissipation member on the back surface of the substrate body,
The substrate body has a plurality of depressions that communicate with the through holes at one end and open along different directions on the back surface of the substrate body,
The heat dissipating member includes a rectangular or circular element mounting surface at a top end in a plan view, the column part having a rectangular column or a columnar shape, and a side surface of the column part in a direction symmetrical to the central axis of the column part. and the plurality of horizontal portions extending, Ri Tona,
The plurality of horizontal portions are individually inserted and fixed in the plurality of depressions,
The element mounting surface located at the upper end of the column part and the horizontal part are not similar to each other in plan view.
A wiring board characterized by that. The width of each horizontal portion of the heat radiating member is the same as the length of each side surface of the column portion in a column portion having a rectangular cross section, or smaller than the length of each side surface, and the column portion having a circular cross section. Less than or equal to the diameter of
The wiring board according to claim 1.

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