Heat dissipation device

Abstract

To provide a heat dissipation device that can dissipate heat generated by heat-generating a component placed on a substrate with high efficiency.SOLUTION: A heat dissipation device includes a substrate 11 and a heat generating component 22. The heat generating component 22 is arranged on a first main surface 11a of the substrate 11. The substrate 11 includes a heat conductive portion 13 and an inner layer wiring 14. The heat conductive portion 13 transfers the heat generated by the heat generating component 22. The inner layer wiring 14 is formed so as to be connected to the heat conductive portion 13 in the substrate 11. A first heat conductive portion 13a which is the heat conductive portion 13 includes a region that overlaps with the heat generating component 22 in a plan view and penetrates the substrate 11. The first heat conductive portion 13a is formed by a first conductive member filled in a first hole formed in the substrate 11, and the first conductive member is provided with a first thread groove on the outer peripheral surface, and in the first hole, a second thread groove is formed on the inner peripheral surface, and the first thread groove and the second thread groove are engaged with each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a heat dissipation device. [Background technology]

[0002] In recent years, with the advancement of semiconductor technology, semiconductor chips with higher output and higher voltage resistance than before have been developed. Furthermore, with the sophistication of systems, electronic components including semiconductor elements are becoming more and more sophisticated. As a result, the amount of heat generated by semiconductor elements, i.e. heat-generating components, is increasing. For example, for high-frequency semiconductor elements, gallium arsenide (GaAs) has been the mainstream substrate material until now. However, in recent years, gallium nitride (GaN) has rapidly become popular as a substrate material for high-frequency semiconductor elements. This has resulted in a several-fold increase in the output of the elements. At the same time, the amount of heat generated by heat-generating components including the semiconductor elements has also increased several-fold.

[0003] In order to cope with the increase in the amount of heat generated by such semiconductor elements, it is necessary to improve the cooling structure. For cooling, it is necessary to transfer heat from a large heat generating portion, such as a semiconductor element included in a heat generating component, to a heat dissipation portion, such as a fin or a heat exchanger. When a semiconductor element that generates a large amount of heat is mounted by surface mounting in an electronic component, for example, a heat generating component such as a semiconductor element is attached to a printed wiring board, as in JP2017-5093A (Patent Document 1).

[0004] However, printed wiring boards are generally made of resin materials and therefore do not have good thermal conductivity. Therefore, when a heat-generating component that generates a lot of heat, such as a semiconductor element, is mounted on the printed wiring board, the heat-generating component becomes hot. In order to improve the thermal conductivity of the printed wiring board, in JP2017-5093A, a heat dissipation mechanism using thermal vias is formed on the printed wiring board. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-5093 A Summary of the Invention [Problem to be solved by the invention]

[0006] In JP 2017-5093 A, high heat dissipation performance from the heat generating component to the heat dissipation fin side is obtained by filling the above-mentioned thermal via with a heat conductive core. However, in recent years, electronic components have become smaller, more functional, and more highly integrated. For this reason, the wiring on the back side or around the electronic components has become denser. This has resulted in a higher heat density of the heat generating components, and there has been a problem in that the cooling performance is insufficient with only the heat dissipation mechanism disclosed in JP 2017-5093 A.

[0007] The present disclosure has been made in view of the above-mentioned problems, and has an object to provide a heat dissipation device capable of highly efficiently dissipating heat generated by a heat-generating component disposed on a substrate. [Means for solving the problem]

[0008] A heat dissipation device according to the present disclosure includes a mounting component including a heat-generating component and a package that houses the heat-generating component; a first main surface having a first hole formed therein and a surface wiring formed on the bottom surface of the package and joined by a conductive bonding member to a pattern of a conductive film that is electrically connected to the heat-generating component; a second main surface opposite to the first main surface; and a first conductive member that penetrates from the first main surface to the second main surface and includes an area that overlaps with the heat-generating component in a plan view and transmits heat generated by the heat-generating component and is filled in the first hole. Table The substrate includes a heat conductive portion having a first heat conductive portion connected to the layer wiring, and an inner layer wiring formed inside the heat conductive portion. The first conductive member has a first thread groove formed on an outer peripheral surface, and the first hole has a second thread groove formed on an inner peripheral surface. and the inner peripheral surface is covered with an inner wall conductive film; The first and second thread grooves are engaged. Effect of the Invention

[0011] According to the present disclosure, it is possible to provide a heat dissipation device capable of highly efficiently dissipating heat generated by a heat-generating component disposed on a substrate. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a first embodiment. [Diagram 2] 10 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a second embodiment. [Diagram 3] FIG. 11 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a third embodiment. [Figure 4] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a first example of embodiment 4. FIG. [Diagram 5] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a second example of the fourth embodiment. FIG. [Figure 6] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a third example of the fourth embodiment. FIG. [Figure 7] 4 is a flowchart showing a manufacturing process of a substrate included in the heat dissipation device of the first embodiment. [Figure 8] FIG. 11 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a fifth embodiment. [Figure 9] 6 is a schematic cross-sectional view showing a bonding step between a substrate and a mounted component in a manufacturing process of the heat dissipation device of FIG. 5. [Figure 10] 20 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a first example of the sixth embodiment. FIG. [Figure 11] 20 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a second example of the sixth embodiment. FIG. [Figure 12] 22 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a third example of the sixth embodiment. FIG. [Figure 13] 23 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a fourth example of the sixth embodiment. FIG. [Figure 14] 20 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a fifth example of the sixth embodiment. FIG. [Figure 15] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a first example of the seventh embodiment. FIG. [Figure 16] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a second example of the seventh embodiment. FIG. [Figure 17] 16 is a schematic cross-sectional view showing a step of inserting a heat conductive part into a hole in a substrate as a first step in a manufacturing process of the heat dissipation device of FIG. 15. [Figure 18] 16 is a schematic cross-sectional view showing a bonding step of the heat conductive portion as a second step in the manufacturing process of the heat dissipation device of FIG. [Figure 19] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a first example of the eighth embodiment. FIG. [Figure 20] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a second example of the eighth embodiment. FIG. [Figure 21] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a third example of the eighth embodiment. FIG. [Figure 22] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a fourth example of the eighth embodiment. FIG. [Figure 23] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a fifth example of the eighth embodiment. FIG. [Figure 24] 13 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a sixth example of the eighth embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the present embodiment will be described with reference to the drawings, in which X, Y, and Z directions are introduced for the sake of convenience.

[0014] Embodiment 1 First, referring to FIG. 1, the general structural features of the heat dissipation device according to the present embodiment will be described. FIG. 1 is a schematic cross-sectional view showing the structure of the heat dissipation device according to the first embodiment. Referring to FIG. 1, the heat dissipation device 100a of the present embodiment mainly includes a substrate 11, a mounted component 21, and a heat dissipation member 31. The substrate 11 has a first main surface 11a which is one of the main surfaces, and a second main surface 11b which is the other main surface opposite to the first main surface 11a. In FIG. 1, the first main surface 11a is the uppermost surface in the Z direction of the substrate 11, particularly the substrate body 12. In FIG. 1, the second main surface 11b is the lowermost surface in the Z direction of the substrate 11, particularly the substrate body 12. The mounted component 21 is placed on the first main surface 11a of the substrate 11 via a solder ball 32 which is a bonding material having high thermal conductivity. The mounted component 21 includes a heat generating component 22 which generates heat when driven. That is, above the first main surface 11a of the substrate 11, a heat generating component 22 is disposed.

[0015] The substrate 11 is a plate material having, for example, a rectangular planar shape, mainly composed of a substrate body 12. That is, the substrate body 12 of the substrate 11 is a plate material having a rectangular first main surface 11a and a second main surface 11b in a direction along the XY plane, and having a certain thickness in the Z direction. The substrate 11 includes a heat conductive portion 13 and an inner layer wiring 14. The heat conductive portion 13 has a function of transmitting heat generated by the heat generating component 22, for example, from the upper side to the lower side in the Z direction of the figure. For this reason, the heat conductive portion 13 extends along the Z direction. The inner layer wiring 14 is formed so as to be connected to the heat conductive portion 13 in the substrate 11. Here, the inner layer wiring 14 is formed so as to be thermally and electrically connected to the heat conductive portion 13 in the substrate 11.

[0016] The thermally conductive portion 13 has a first thermally conductive portion 13a. The first thermally conductive portion 13a includes an area overlapping with the heat generating component 22 in a plan view. In FIG. 1, the first thermally conductive portion 13a overlaps with the heat generating component 22 in a plan view. The first thermally conductive portion 13a is arranged so as to fill almost the entire inside area of ​​a hole 15 (first hole) formed so as to penetrate the substrate 11, particularly the substrate body 12, from the first main surface 11a to the second main surface 11b on the opposite side. That is, the first thermally conductive portion 13a is arranged so as to penetrate the substrate 11, particularly the substrate body 12, from the first main surface 11a to the second main surface 11b. The first thermally conductive portion 13a is, for example, a structure made of a conductive material arranged in the hole 15 (first hole). Specifically, the first thermally conductive portion 13a is formed of a metal lump of a material having a high thermal conductivity, such as copper. Hereinafter, such a metal lump will be referred to as a core material.

[0017] In other words, the first heat conducting portion 13a is formed by a first conductive member filled in a hole 15 (first hole) formed in the substrate 1. The first conductive member has a first screw groove formed on its outer circumferential surface. Here, the outer circumferential surface of the first conductive member refers to the surface between the surface of the first conductive member facing the heat generating component 22 and the surface opposite to the surface facing the heat generating component 22. Also, the hole 15 (first hole) has a second screw groove formed on its inner circumferential surface. Here, the inner circumferential surface of the hole 15 (first hole) refers to the surface that becomes the inner wall of the hole 15 (first hole). The substrate 11 and the first heat conducting portion 13a are engaged by screwing so that the first screw groove and the second screw groove mesh with each other. 1, the first conductive member which is the first heat conducting portion 13a is formed from a portion formed inside the hole 15 (first hole) and a portion protruding to the outside of the hole 15 (first hole). This gives the first conductive member a screw-like shape.

[0018] Specifically, the surface of the first conductive member opposite to the surface facing the heat generating member 22 protrudes to the outside of the hole 15 (first hole). The portion of the first conductive member protruding to the outside of the hole 15 (first hole) has a larger dimension in the X direction and the Y direction than the portion formed inside. That is, the portion of the first conductive member protruding to the outside of the hole 15 (first hole) has a larger diameter than the hole 15 (first hole). This makes the first conductive member have a screw-like shape. Specifically, the portion of the first conductive member protruding to the outside of the hole 15 (first hole) becomes the head of the screw, and the portion formed inside the hole 15 (first hole) becomes the shaft of the screw. In the portion of the first conductive member protruding to the outside of the hole 15 (first hole), the surface facing the substrate 11 is bonded to the substrate 11 by adhesive, solder, or the like. Here, the first conductive member has a portion protruding out of the hole 15 (first hole), but may have no portion protruding out of the hole 15 (first hole) as necessary. The first conductive member may also have a surface side facing the heat generating member 22 protruding out of the hole 15 (first hole). In this case, the protruding portion of either the surface side facing the heat generating member 22 or the surface side opposite to the surface facing the heat generating member 22 of the first conductive member has the same dimensions in the X and Y directions as the portion formed inside. In other words, either the surface side facing the heat generating member 22 of the first conductive member or the protruding portion of the surface opposite to the surface facing the heat generating member 22 becomes the axis of the screw, like the portion formed inside the hole 15 (first hole). The heat dissipation device 100a of FIG. 1 will be described in more detail below.

[0019] <Board configuration> The substrate 11 is, for example, a printed wiring board. The substrate body 12 of the substrate 11 is formed of a generally known resin material. As described later, the substrate body 12 is formed by stacking a plurality of plate materials, each of which is thinner than the substrate 11 of FIG. 1 in the Z direction, in the Z direction and integrating them together. A pattern of the inner layer wiring 14 is formed on one or the other main surface of each of the plurality of stacked thin plate materials. The pattern of the inner layer wiring 14 is, for example, a thin film pattern formed of copper.

[0020] Hole 15 penetrates substrate body 12 from first main surface 11a to second main surface 11b of substrate 11. Hole 15 (first hole) penetrating substrate body 12 from first main surface 11a to second main surface 11b is formed in the center in the X direction in Fig. 1, and is formed to include a region overlapping with heat generating component 22 in a plan view. In Fig. 1, only one hole 15 (first hole) penetrating substrate body 12 is formed in the center of substrate body 12. A first heat conductive part 13a is inserted inside hole 15 (first hole).

[0021] In addition, multiple layers of inner layer wiring 14 are formed on substrate 11 at intervals in the Z direction. However, surface layer wiring 17 is formed on first main surface 11a of substrate 11. The pattern of surface layer wiring 17 is formed of the same material and thickness as the pattern of inner layer wiring 14. In other words, surface layer wiring 17 is a thin film pattern made of, for example, copper.

[0022] <Configuration of mounting parts> The mounting component 21 includes a heat generating component 22 and a package 23. The heat generating component 22 is a semiconductor element having a semiconductor transistor or a diode formed on a substrate of, for example, silicon (Si), gallium nitride, or gallium arsenide. The heat generating component 22 generates heat when the semiconductor element is driven. The package 23 is a case-shaped member formed of a single-layer or multi-layer resin substrate or a ceramic substrate. However, the package 23 may be a case-shaped member made of metal. The package 23 houses the heat generating component 22 inside. The package 23 is preferably any one selected from the group consisting of a gull-wing package, a flat-lead package, a QFN (Quad For Non-Lead) package, and a BGA (Ball Grid Array) package. The heat generating component 22 is bonded to the inside of the package 23, for example, on the bottom surface, by a bonding layer 24 such as solder.

[0023] <Other materials> A heat dissipation member 31 is joined to the substrate 11 so as to contact the surface wiring on the second main surface 11b of the substrate 11. That is, the heat dissipation member 31 is joined to the second main surface 11b side of the substrate 11, which is opposite to the first main surface 11a side on which the mounting components 21 including the heat-generating components 22 are mounted. The heat dissipation member 31 is a commonly known heat sink made of, for example, copper. However, the heat dissipation member 31 is not limited to this, and other coolers may be used as the heat dissipation member 31.

[0024] A plurality of solder balls 32 are arranged at intervals from one another so as to contact surface wiring 17 and plating film 17a on first main surface 11a of substrate 11. These solder balls 32 are arranged so as to contact a conductive film pattern formed on the bottom surface of package 23. The conductive film pattern of package 23 is preferably electrically connected to a semiconductor element included in heat-generating component 22. Thus, solder balls 32 electrically connect substrate 11 and mounted component 21.

[0025] In this embodiment, the solder balls 32 are preferably made of a highly thermally conductive and reflowable joining material, such as a solder material containing a metal core or silver paste, so that the solder balls 32 can connect the substrate 11 and the mounted components 21 with low thermal resistance.

[0026] <Operation of heat dissipation device> Heat dissipation device 101 having the above configuration operates as follows. Heat generated in heat generating component 22 by driving the semiconductor element is transferred via package 23 and solder balls 32 to first heat conductive portion 13a of substrate 11, which overlaps heat generating component 22 in a planar manner. First heat conductive portion 13a can dissipate heat to the heat dissipation member 31 directly below. First heat conductive portion 13a is connected to inner layer wiring 14 directly or via inner wall conductive film 16 on the inner wall surface of hole 15 (first hole) in which first heat conductive portion 13a is disposed.

[0027] Next, a manufacturing process for the heat dissipation device 100a of FIG. 1, particularly for the substrate 11, will be described with reference to the flowchart of FIG. 7. FIG. 7 is a flowchart showing a manufacturing process for the substrate included in the heat dissipation device of the first embodiment. Referring to FIG. 7, a preparation step (S10) is performed first. Specifically, a plurality of thin rectangular resin plate members to become the substrate body 12 are prepared. A wiring pattern, for example of copper, is formed on one or both main surfaces of each of the plurality of plate members.

[0028] Next, a lamination step (S20) is performed. Each plate is stacked with a sheet called a prepreg placed on top of the plate. Then, a bonding step (S30) is performed. The stacked plate is exposed to high temperature and high pressure. As a result, the prepreg bonds the plate together. The above steps (S20) and (S30) may be repeated multiple times until the required thickness of the substrate 11 in the Z direction is achieved.

[0029] When the substrate 11 is formed to a required thickness, a hole 15 (first hole) is formed through the substrate 11 so as to penetrate the entire substrate body 12 from the first main surface 11a to the second main surface 11b in a drilling process (S40). Thereafter, a second thread groove is formed in the inner peripheral surface, which is the inner wall surface of the hole 15 (first hole), or in the inner wall conductive film 16 covering the inner peripheral surface. In addition, a thin copper film may be formed as the inner wall conductive film 16 on the inner wall surface of the hole 15 (first hole) by, for example, a plating process.

[0030] Then, a first thread groove is formed on the outer peripheral surface of the first conductive member of the first heat conducting portion 13a. In addition, a portion of the first conductive member that is formed outside the hole portion 15 (first hole portion) and has a diameter larger than that of the hole portion 15 (first hole portion) is formed. The first conductive member of the first heat conducting portion 13a is inserted into the hole portion 15 (first hole portion) that penetrates the entire substrate 11. At this time, the substrate 11 and the first heat conducting portion 13a are engaged by screwing so that the first thread groove formed in the first conductive member and the second thread groove formed in the hole portion 15 (first hole portion) engage with each other. The first conductive member fills almost the entire hole portion 15. At least a part of the first conductive member contacts the inner layer wiring 14 exposed as the inner wall surface of the hole portion 15 (first hole portion) or the inner wall conductive film 16 covering the inner wall surface. The first thermally conductive portion 13a is formed of a first conductive member, which is a core material previously shaped into a metal block. After the core material is inserted, a heat treatment process and a chemical process may be performed as necessary.

[0031] Thereafter, if necessary, a hole-filling resin may be filled into the gap between the inner wall surface of hole 15 in substrate body 12 and the core material of heat conductive portion 13 filled therein. In this way, heat conductive portion 13 is fixed in hole 15 without the interposition of a resin material.

[0032] Next, the effects of this embodiment will be described.

[0033] The heat dissipation device according to the present disclosure includes a substrate 11 and a heat generating component 22. The heat generating component 22 is disposed on a first main surface 11a of the substrate 11. The substrate 11 includes a heat conducting portion 13 and an inner layer wiring 14. The heat conducting portion 13 transmits heat generated by the heat generating component 22. The inner layer wiring 14 is formed so as to be connected to the heat conducting portion 13 within the substrate 11. The heat conducting portion 13 has a first heat conducting portion 13a. The first heat conducting portion 13a includes an area overlapping with the heat generating component 22 in a plan view, and penetrates the substrate 11 from the first main surface 11a to a second main surface 11b opposite to the first main surface 11a. The first heat conducting portion 13a is formed by a first conductive member filled in a hole portion 15 (inside a first hole portion) formed in the substrate 11. The first conductive member has a first thread groove formed on an outer circumferential surface. A second screw groove is formed on the inner circumferential surface of the hole 15 (first hole) formed in the substrate 11. The first screw groove and the second screw groove are engaged with each other. This has the advantage of providing a higher joint strength than when only adhesive and solder are used for the fixing method, and allows for highly efficient heat dissipation. In addition, the high joint strength reduces the occurrence of cracks in the solder at the joint. Furthermore, when attaching the first conductive member to the substrate 11, the member is attached by screwing, which eliminates the need for a press-in process and allows for easy attachment. Furthermore, the first conductive member has a portion protruding out of the hole 15. Therefore, even if the thickness of the first conductive member in the Z direction is shorter than the thickness of the substrate 11 in the Z direction, the first conductive member can be fixed to the substrate 11 at the portion protruding out of the hole 15. Therefore, even if the thickness of the first conductive member in the Z direction is different from the thickness of the substrate 11 in the Z direction, the first conductive member can be easily attached to the substrate 11.

[0034] Embodiment 2 FIG. 2 is a schematic cross-sectional view showing a configuration according to a heat dissipation device of the second embodiment. In each of the following figures, the same reference numerals are used for components substantially the same as those in FIG. 1, and the description of the configuration and features substantially similar to those in FIG. 1 will not be repeated. That is, in the description of each of the following examples, the configuration and features different from those in FIG. 1 or other existing examples will be mainly described. With reference to FIG. 2, in this embodiment, the first heat conduction portion 13h is the first heat conduction portion 13a in FIG. 1 further having a heat dissipation fin formed thereon. In detail, the first heat conduction portion 13h is the first heat conduction portion 13a in FIG. 1 having a heat dissipation fin formed on the surface opposite to the surface facing the heat generating component 22. In addition, the first conductive member which is the first heat conduction portion 13h is formed of a portion formed inside the hole portion 15 (first hole portion) and a portion protruding to the outside of the hole portion 15 (first hole portion) in the same manner as the first heat conduction portion 13a. The heat dissipation fin is formed on the portion protruding to the outside. That is, since the first conductive member has a portion protruding outward from the hole portion 15 (first hole portion), it is possible to form a heat dissipation fin on this protruding portion. Here, like the first thermal conductive portion 13a, the first thermal conductive portion 13h is engaged with the substrate 11 by screwing the first thermal conductive portion 13h so that the first thread groove formed in the first conductive member and the second thread groove formed in the hole portion 15 (first hole portion) engage with each other. However, if necessary, the first thermal conductive portion 13h may be configured not to have the first thread groove formed therein, and to be inserted into the hole portion 15 (first hole portion) by press-fitting. In that case, the second thread groove is not formed on the inner circumferential surface of the hole portion 15 (first hole portion).

[0035] The following describes the effects of the second embodiment that are obtained in addition to those of the first embodiment. This also applies to the description of the effects of the following embodiments. It is possible to dissipate heat directly from the first heat conducting portion 13h, and heat can be dissipated with high efficiency. Although the figure shows a configuration with a heat dissipation member 31, it is possible to dissipate heat from the heat dissipation fins formed on the first heat conducting portion 13h even in a configuration without the heat dissipation member 31. The first heat conducting portion 13h has high bonding strength because the substrate 11 and the first heat conducting portion 13h are engaged with each other by screws. Therefore, a part of the first heat conducting portion 13h can be processed into a large heat dissipation fin or the like to obtain a high heat dissipation effect.

[0036] Embodiment 3 3, in this embodiment, the first heat conducting portion 13h is the first heat conducting portion 13a in FIG. 1 or the heat conducting portion 13h in FIG. 2, in which the heat dissipation member 31 and the first heat conducting portion 13 are fixed by a fastening member such as a screw. Here, the heat dissipation member 31 and the first heat conducting portion 13 are fixed by a fastening member in the heat dissipation device 100a in FIG. 1. As shown in FIG. 3, the first conductive member which is the first heat conducting portion 13i is formed of a portion formed inside the hole portion 15 (first hole portion) and a portion protruding to the outside of the hole portion 15 (first hole portion) like the first heat conducting portion 13a. In the first heat conducting portion 13i, a hole portion is formed on the surface opposite to the surface facing the heat generating component 22 in the portion protruding to the outside, and a screw groove is further formed in the hole portion by tapping or the like. In other words, since the first conductive member has a portion that protrudes outward from hole 15 (first hole), it is possible to form a hole and a screw groove in this portion that protrudes outward.

[0037] The heat dissipation member 31 is provided on the surface of the first heat conduction section 13i opposite to the surface facing the heat generating component 22. The heat dissipation member 31 also has a hole formed in a portion overlapping the hole formed in the first heat conduction section 13i. A fastening member such as a screw is inserted between the hole formed in the heat dissipation member 31 and the hole formed in the first heat conduction section 13i. The heat dissipation member 31 and the first heat conduction section 13i are fixed by the fastening member. Note that here, like the first heat conduction section 13a, the first heat conduction section 13i engages the substrate 11 and the first heat conduction section 13h by screwing them together so that the first screw groove formed in the first conductive member and the second screw groove formed in the hole 15 (first hole) engage with each other. However, if necessary, first heat conductive portion 13i may be configured not to have the first thread groove formed therein and to be inserted into hole portion 15 (first hole portion) by press-fitting. In that case, the second thread groove is not formed on the inner circumferential surface of hole portion 15 (first hole portion).

[0038] The following describes additional effects of the third embodiment in addition to those of the first and second embodiments. In the heat dissipation device 100c, even a large-area heat dissipation member 31 can be firmly attached by a fastening member, and as a result, the cooling efficiency can be improved. In addition, since the portion where the heat dissipation member 31 and the first heat conductive portion 13i are joined can be the portion of the first heat conductive portion 13i, there is no need to provide holes for inserting joining members in other portions of the substrate 11, and more space can be secured for arranging the inner layer wiring 14.

[0039] Embodiment 4 FIG. 4 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a fourth embodiment. With reference to FIG. 4, in this embodiment, the heat dissipation device in any one of FIGS. 1 to 3 has a second heat conductive portion 13b. Here, the heat dissipation device in FIG. 1 having the second heat conductive portion 13b is shown. The second heat conductive portion 13b is arranged around the first heat conductive portion 13a with a gap therebetween in the X direction or Y direction of the figure. The second heat conductive portion 13b is also arranged so as to fill almost the entire inside of the hole portion 15 (second hole portion) formed, for example, extending in the Z direction of the figure, inside the substrate 11, particularly the substrate body 12. However, the second heat conductive portion 13b is arranged with a gap from at least one of the first main surface 11a and the second main surface 11b. The second heat conductive portion 13b is a structure made of a conductive material arranged, for example, inside the hole portion 15 (second hole portion). Specifically, the second thermally conductive portion 13b is formed of a metal mass, that is, a core material, of a material with high thermal conductivity, such as copper.

[0040] In other words, the hole 15 (second hole) in which the second heat conductive portion 13b is disposed is formed inside the first main surface 11a and the second main surface 11b so as not to be exposed to at least one of them. For example, in FIG. 1, the hole 15 (second hole) in which the second heat conductive portion 13b is disposed is formed so as not to be exposed to the first main surface 11a but only to the second main surface 11b, that is, so as to be connected only to the second main surface 11b. As a result, the second heat conductive portion 13b in FIG. 1 is exposed to the second main surface 11b, does not connect to the first main surface 11a, and is disposed so as to be spaced apart from the first main surface 11a in the Z direction.

[0041] The holes 15 include those (first holes) that penetrate the substrate body 12 from the first main surface 11a to the second main surface 11b of the substrate 11, and those (second holes) that extend only a part of the substrate body 12 in the Z direction and communicate with only either the first main surface 11a or the second main surface 11b. As in FIGS. 1 to 3, the former hole 15 (first hole) that penetrates the substrate body 12 from the first main surface 11a to the second main surface 11b is formed in the center in the X direction in FIG. 4, and is formed to include an area that overlaps with the heat generating component 22 in a plan view. In FIG. 4, only one hole 15 (first hole) that penetrates the substrate body 12 is formed in the center of the substrate body 12. The first heat conducting part 13a is inserted into the hole 15 (first hole). In contrast, the latter hole 15 (second hole) that extends only partially through the substrate body 12 is formed around the hole 15 (first hole) into which the first heat conductive portion 13a is inserted, at intervals from the hole 15 in the X and Y directions. In FIG. 4, some of the holes 15 (second hole) among the plurality of non-penetrating holes 15 (second hole) extend downward in the Z direction from the first main surface 11a. These holes 15 (second hole) are formed on the upper side in the Z direction in FIG. 4, and are hereinafter referred to as upper non-penetrating holes 15 (second hole). In FIG. 4, other holes 15 (second hole) among the plurality of non-penetrating holes 15 (second hole) extend upward in the Z direction from the second main surface 11b. These holes 15 (second holes) are formed on the lower side in the Z direction in FIG. 4, and therefore will hereinafter be referred to as lower non-through holes 15 (second holes).

[0042] In FIG. 4, the upper non-through hole 15 (second hole) and the lower non-through hole 15 (second hole) overlap each other in a plan view. In FIG. 4, the non-through holes 15 (second hole) are narrower in width in the X direction than the central through hole 15 (first hole). Although not shown, the non-through holes 15 (second hole) may be narrower in width in the Y direction than the central through hole 15 (first hole). In FIG. 4, two rows of non-through holes 15 (second hole) are formed on the left and right sides of the central through hole 15 (first hole), but the number of rows is arbitrary.

[0043] Of these multiple non-through holes 15 (second holes), the second heat conductive portion 13b is inserted into the lower non-through hole 15 (second hole). As a result, the second heat conductive portion 13b as a core material is arranged to communicate with the second main surface 11b. On the other hand, in FIG. 1, the second heat conductive portion 13b as a core material is not inserted into the upper non-through hole 15 (second hole) among the multiple non-through holes 15.

[0044] That is, in Fig. 4, the first heat conducting portion 13a and the second heat conducting portion 13b as the heat conducting portion 13 both communicate with the second main surface 11b. On the other hand, the first heat conducting portion 13a communicates with the first main surface 11a, but the second heat conducting portion 13b does not communicate with the first main surface 11a. Therefore, in Fig. 4, the sum of the areas of the portions of the first heat conducting portion 13a and the second heat conducting portion 13b as the heat conducting portion 13 that communicate with the second main surface 11b is greater than the sum of the areas of the portions of the first heat conducting portion 13a and the second heat conducting portion 13b as the heat conducting portion 13 that communicate with the first main surface 11a.

[0045] Among these multiple non-through holes 15, the second heat conductive portion 13b inserted into the lower non-through hole 15 (second hole) and filling the hole 15 is a core material made of a conductive material such as copper. In contrast, inside the upper non-through hole 15 (second hole), a second conductive material such as copper that covers the inner wall of the hole 15 may be formed as the second heat conductive portion instead of the conductive material as the core material. This conductive material is the inner wall conductive film 16. The inner wall conductive film 16 may also be formed on the inner wall surface of the lower non-through hole 15 (second hole) into which the second heat conductive portion 13b as the core material is filled. In FIG. 1, the inner wall conductive film 16 is also formed on the inner wall surface of the lower non-through hole 15 (second hole).

[0046] Although not shown here, the second conductive member, which is the second heat conducting portion 13b, may be engaged by screwing to the substrate 11 in the same manner as the first conductive member in FIG. 1. In this case, the second conductive member has a first screw groove formed on its outer circumferential surface. Also, the second conductive member, which is the second heat conducting portion 13b, may be formed of a portion formed inside the hole portion 15 (second hole portion) and a portion protruding to the outside of the hole portion 15 (second hole portion) in the same manner as the first conductive member in FIG. 1. Also, the hole portion 15 (second hole portion) has a second screw groove formed on its inner circumferential surface. The substrate 11 and the second heat conducting portion 13b are engaged by screwing so that the first screw groove and the second screw groove are engaged. Furthermore, although not shown here, the second heat conducting portion 13b may have a configuration in which a heat dissipation fin is formed on the surface opposite to the surface facing the heat generating component 22 in the same manner as the first heat conducting portion h in FIG. 2. Furthermore, although not shown here, second heat conducting portion 13b may be configured such that heat dissipation member 31 and second heat conducting portion 13b are fixed together by a fastening member such as a screw, similar to heat conducting portion 13i in Fig. 3. In more detail, second heat conducting portion 13b may be configured to be fixed together by a fastening member inserted into a hole formed in heat dissipation member 31 and a hole formed in second heat conducting portion 13b.

[0047] The second heat conductive portion 13b is inserted into a non-through hole 15 (second hole) having smaller dimensions in the Z direction, X direction, and Y direction than the hole 15 into which the first heat conductive portion 13a is inserted. Therefore, in Fig. 4, the second heat conductive portion 13b has smaller dimensions than the first heat conductive portion 13a. However, this is not limited to the above, and for example, a plurality of first heat conductive portions 13a, each of which is approximately the same size as the second heat conductive portion 13b, may be inserted into the central hole 15 (first hole).

[0048] In FIG. 4, the sizes of the non-through holes 15 (second holes) arranged in a plurality of rows in the X direction have the following characteristics. That is, as the center hole 15 (first hole) is approached, the lower non-through holes 15 (second holes) extend longer in the Z direction, and the upper non-through holes 15 (second holes) extend shorter in the Z direction. In this way, more space can be secured for arranging the inner layer wiring 14. However, this is not limited to this embodiment. As long as the arrangement space for the inner layer wiring 14 can be secured, for example, among the non-through holes 15 (second holes) in each row, the upper non-through holes 15 (second holes) and the lower non-through holes 15 (second holes) that overlap each other in a plan view may have approximately the same length extending in the Z direction.

[0049] Also, as shown in Fig. 4, the total number of core materials of the heat conductive portion 13 that communicates with the second main surface 11b side may be greater than the total number of core materials of the heat conductive portion 13 that communicates with the first main surface 11a side. Specifically, in Fig. 4, the core material that communicates with the first main surface 11a is only one first heat conductive portion 13a. In contrast, in Fig. 4, the core materials that communicate with the second main surface 11b are one first heat conductive portion 13a and four second heat conductive portions 13b, making a total of five.

[0050] 4, the inner layer wiring 14 is arranged to connect the first heat conductive portion 13a and the second heat conductive portion 13b. Here, the inner layer wiring 14 thermally and electrically connects the first heat conductive portion 13a and the second heat conductive portion 13b.

[0051] Specifically, for example, a first heat conductive portion 13a as a core material and a second heat conductive portion 13b as a core material are filled in a hole 15 formed in the substrate 11. As described later, these holes 15 are formed as portions of a resin substrate body 12 and a thin film pattern of copper or the like formed thereon to become the inner layer wiring 14, which are missing portions. Therefore, the inner layer wiring 14 is exposed on at least a part of the inner wall surface of the hole 15. A heat conductive portion 13 of a conductive material as a core material is inserted into the hole 15. At least a part of the surface of the heat conductive portion 13 contacts the exposed portion of the inner layer wiring 14 forming the inner wall surface of the hole 15. As a result, the first heat conductive portion 13a and the second heat conductive portion 13b are connected to the inner layer wiring 14 at the portion where the heat conductive portion 13 in the hole 15 contacts the inner layer wiring 14 exposed on the inner wall surface of the hole 15. These connections are made thermally and electrically.

[0052] However, the heat conductive portion 13 and the inner layer wiring 14 in the hole 15 may be connected to each other so that another conductive member such as the inner wall conductive film 16 as a plating film on the inner wall surface or a thin resin is sandwiched between them. Even in this case, the heat conductive portion 13 and the inner layer wiring 14 are at least thermally connected to each other through the inner wall conductive film 16 and a member such as a thin resin between them. In other words, heat can be conducted between the heat conductive portion 13 and the inner layer wiring 14. Therefore, in this embodiment, the heat conductive portion 13, i.e., the first heat conductive portion 13a and the second heat conductive portion 13b are defined as being "connected" to the inner layer wiring 14, including such a case. Also, the first heat conductive portion 13a and the second heat conductive portion 13b are at least thermally connected to each other through the inner wall conductive film 16 in the hole 15 into which the first heat conductive portion 13a is inserted and the inner wall conductive film 16 in the hole 15 into which the second heat conductive portion 13b is inserted. For this reason, the inner layer wiring 14 is disposed so as to connect, i.e. at least thermally connect, the first heat conductive portion 13a and the second heat conductive portion 13b, for example, via the inner wall conductive film 16. However, it is more preferable that the heat conductive portion 13 and the inner layer wiring 14 are electrically connected, for example, via the inner wall conductive film 16. It is also more preferable that the inner layer wiring 14 is electrically connected between the first heat conductive portion 13a and the second heat conductive portion 13b, via the inner wall conductive film 16.

[0053] A plating film 17a having the same material and thickness as the surface wiring 17 is formed directly above the upper non-penetrating hole 15 (second hole). The plating film 17a is a thin copper film formed by plating, for example. The plating film 17a is a conductive film formed so as to compensate for the portion of the inner wiring 14 removed by the formation of the hole 15. Therefore, the plating film 17a is formed so as to cover the hole 15 from above in the Z direction.

[0054] The second heat conductive portion 13b is connected to the inner layer wiring 14 directly or via the inner wall conductive film 16 on the inner wall surface of the hole 15 in which it is arranged. That is, the first heat conductive portion 13a is at least thermally connected to the second heat conductive portion 13b via the inner layer wiring 14. Therefore, the heat transferred to the first heat conductive portion 13a can be transferred to the second heat conductive portion 13b via the inner layer wiring 14. The second heat conductive portion 13b can dissipate heat to the heat dissipation member 31 directly below it, similar to the first heat conductive portion 13a.

[0055] FIG. 5 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a second example of the fourth embodiment. With reference to FIG. 5, in a heat dissipation device 102 according to the second example of the present embodiment, a plurality of holes 15 (first holes) are formed at intervals in the center of the substrate body 12. Although three holes 15 (first holes) are shown in FIG. 5 as an example, the number of holes 15 is not limited to this. Then, first heat conductive parts 13a are inserted into the holes 15. Therefore, each first heat conductive part 13a in FIG. 5 has smaller dimensions in the X direction and the Y direction than each first heat conductive part 13a in FIG. 4.

[0056] FIG. 6 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a third example of the fourth embodiment. Referring to FIG. 6, in the heat dissipation device 103 of the third example of the present embodiment, the upper non-through hole 15 (second hole) closest to the central through hole 15 has a lower non-through hole 15 (second hole) so as to overlap with it in a plan view, as in the other examples described above. The lower non-through hole 15 (second hole) is filled with the second heat conductive portion 13b. However, the upper non-through hole 15 (second hole) on the outer side does not overlap with the lower non-through hole 15 (second hole) in a plan view. And, further outside the upper non-through hole 15 (second hole), a lower non-through hole 15 (second hole) is provided. The inside of the lower non-through hole 15 (second hole) is not filled with the second heat conductive portion 13b. The outer upper non-through hole portion 15 (second hole portion) and the outer lower non-through hole portion 15 (second hole portion) are connected by an inner layer wiring 14.

[0057] In the heat dissipation device 103, a non-conductive heat dissipation sheet 33 is disposed between the substrate 11 and the heat dissipation member 31. The non-conductive heat dissipation sheet 33 is made of an insulating material with high thermal conductivity, such as epoxy resin. The non-conductive heat dissipation sheet 33 is a flat-plate-shaped member. This is on the second main surface 11b side of the substrate 11 and is joined to the upper side of the heat dissipation member 31 in the Z direction.

[0058] There are cases where it is desired to avoid connecting the upper non-through hole 15 (second hole) to the heat dissipation member 31 that also functions as a frame ground. However, if the hole 15 is made non-through for that purpose, the hole 15 does not reach the second main surface 11b, and therefore the heat dissipation performance is poor. Therefore, as shown in FIG. 3, a non-conductive heat dissipation sheet 33 is disposed between the substrate 11 and the heat dissipation member 31. As a result, as shown in FIG. 3, the upper non-through hole 15 (second hole) and the lower non-through hole 15 (second hole) are electrically connected by the inner layer wiring 14 or the like, and an integrated structure is obtained. The integrated structure enables heat dissipation from the mounted component 21 to the heat dissipation member 31 below, and therefore the heat dissipation function of the entire heat dissipation device 103 is improved.

[0059] In the manufacturing process of the heat dissipation devices 101, 102, and 103 shown in Figs. 4 to 6, the following steps are further performed in the preparation step (S10) in the manufacturing process of the heat dissipation devices 100a, 100b, and 100c shown in Figs. 1 to 3. After a wiring pattern, for example of copper, is formed on one or both main surfaces of each of the plurality of plate materials, a via is formed in each of the plurality of plate materials, penetrating the plate materials from one main surface to the other main surface on the opposite side. It is preferable that the via is formed so that, for example, when one plate material and another plate material among the plurality of plate materials are overlapped, the via of the one plate material and the via of the other plate material overlap at the same position. In particular, it is preferable that, when the plurality of plate materials are overlapped, the above-mentioned vias overlap each other to form a non-penetrating hole portion 15 (second hole portion) of the substrate 11 shown in any one of Figs. 1 to 3. In addition, a thin copper film is formed on the inner wall surface of the via as a film to become the inner wall conductive film 16, for example, by a plating process. In the next lamination step (S20), non-penetrating holes 15 (second holes) are formed by connecting the vias to each other.

[0060] When the substrate 11 is formed to a required thickness, a hole 15 (first hole) is formed in the substrate 11 so as to penetrate the entire substrate body 12 from the first main surface 11a to the second main surface 11b in a hole drilling process (S40). A thin copper film may also be formed as an inner wall conductive film 16 on the inner wall surface of the hole 15, for example, by a plating process. When the core material of the second heat conductive portion 13b is configured to have a first thread groove, a second thread groove is formed on the inner peripheral surface which is the inner wall surface of the hole 15 or on the inner wall conductive film 16 which covers the inner peripheral surface.

[0061] Thereafter, the core material of the second heat conducting portion 13b is inserted, for example, by a press-fitting process into the hole portion 15 that does not penetrate the substrate 11, particularly into the hole portion 15 that is formed to communicate with the second main surface 11b. In addition, in the case where the core material of the second heat conducting portion 13b is configured to have a first screw groove, the first screw groove is formed on the outer peripheral surface of the second conductive member of the second heat conducting portion 13b, similarly to the first heat conducting portion 13b. At this time, the substrate 11 and the second heat conducting portion 13b are engaged by screwing so that the first screw groove formed on the second conductive member and the second screw groove formed in the hole portion 15 engage with each other. The second heat conducting portion 13b is a core material that has been shaped in advance to become a metal lump. After the core material is inserted, a heat treatment process and a chemical process may be performed as necessary.

[0062] Thereafter, if necessary, a hole-filling resin may be filled into the gap between the inner wall surface of the hole 15 of the substrate body 12 and the core material of the thermally conductive portion 13 filled therein. Alternatively, the thermally conductive portion 13 inserted into the hole 15 may be partially crimped by a press-fitting process. In this way, the thermally conductive portion 13 is fixed in the hole 15 without the intervention of a resin material.

[0063] Next, effects of the fourth embodiment that are obtained in addition to the effects of the above-mentioned embodiments will be described. The heat dissipation device according to the present disclosure includes a substrate 11 and a heat generating component 22. The heat generating component 22 is disposed on a first main surface 11a of the substrate 11. The substrate 11 includes a heat conducting portion 13 and an inner layer wiring 14. The heat conducting portion 13 transmits heat generated by the heat generating component 22. The inner layer wiring 14 is formed so as to be connected to the heat conducting portion 13 within the substrate 11. The heat conducting portion 13 has a first heat conducting portion 13a. The first heat conducting portion 13a includes an area overlapping with the heat generating component 22 in a plan view, and penetrates the substrate 11 from the first main surface 11a to the second main surface 11b opposite to the first main surface 11a. The first heat conducting portion 13a is formed by a first conductive member filled in a hole portion 15 (inside a first hole portion) formed in the substrate 11. The first conductive member has a first thread groove formed on its outer circumferential surface. A second thread groove is formed on an inner circumferential surface of a hole 15 (first hole) formed in the substrate 11. The first thread groove and the second thread groove are engaged with each other.

[0064] The heat conducting portion 13 also has a second heat conducting portion 13b. The second heat conducting portion 13b is disposed around the first heat conducting portion 13a with a gap therebetween, and is disposed with a gap therebetween from at least one of the first main surface 11a and the second main surface 11b. The heat of the heat-generating component 22 is directly transmitted to the first heat conducting portion 13a including the area overlapping with the heat-generating component 22 in a plan view. The heat conducting portion 13 and the inner layer wiring 14 are disposed so as to be connected, particularly thermally connected. Therefore, the heat transmitted to the first heat conducting portion 13a is transmitted to the inner layer wiring 14, and is easily transmitted from there to the second heat conducting portion 13b. This allows the heat of the heat-generating component 22 to be dispersed not only to the first heat conducting portion 13a but also to the surrounding second heat conducting portion 13b. Therefore, heat can be dissipated from first heat conductive portion 13a and second heat conductive portion 13b to the outside of heat dissipation device 101, etc. In other words, the thermal resistance of the heat dissipation route can be reduced compared to the case where only first heat conductive portion 13a is provided. As a result, high heat dissipation performance can be achieved in heat dissipation devices 101 to 103 as a whole.

[0065] Heat from the heat-generating component 22 is transferred with high heat dissipation to the first heat conductive portion 13a located directly below it. However, if there was only a route for transferring heat from there to the heat dissipation member 31 located directly below, there is still a possibility that the heat dissipation function will be insufficient. Therefore, an additional route for transferring heat from the first heat conductive portion 13a to the second heat conductive portion 13b is provided via the inner layer wiring 14 that is thermally connected to the first heat conductive portion 13a. Therefore, in the heat dissipation devices 101 to 103, the number of heat dissipation routes from the heat-generating component 22 to the heat dissipation member 31 is increased, and even higher heat dissipation performance can be achieved.

[0066] The second heat conductive portion 13b is disposed, for example, at a distance from the first main surface 11a. Conversely, the second heat conductive portion 13b is disposed, for example, on the second main surface 11b side. This can further enhance the heat dissipation function of the second heat conductive portion 13b toward the heat dissipation member 31 side, particularly on the second main surface 11b side of the substrate 11 opposite to the first main surface 11a side on which the heat generating component 22 is disposed.

[0067] Also, the second heat conducting portion 13b is arranged, for example, at a distance from the first main surface 11a. Therefore, the space for routing the power supply and control signals of the mounted components 21 can be increased, particularly in the region in the substrate 11 close to the first main surface 11a. The number of power supplies and control signals of the mounted components 21 to be arranged around the first heat conducting portion 13a in the substrate 11 is restricted by the power supplies and control signals of the mounted components 21 arranged around the first heat conducting portion 13a. The region in the substrate 11 close to the first main surface 11a in particular is set as the arrangement region for the power supply and control signals. As a result, the region in the substrate 11 close to the second main surface 11b, which is the opposite side to the side where the heat generating components 22 are arranged, can be set as the region where the second heat conducting portion 13b is arranged and the heat of the heat generating components 22 is released from the second heat conducting portion 13b to the outside of the heat dissipation device.

[0068] From the viewpoint of achieving the above effects, in the heat dissipation device, it is preferable that the second heat conducting portion 13b is arranged so as to be connected to the second main surface 11b. In the heat dissipation device, it is preferable that the sum of the areas of the portions of the first heat conducting portion 13a and the second heat conducting portion 13b as the heat conducting portion 13 that are connected to the second main surface 11b is larger than the sum of the areas of the portions of the first heat conducting portion 13a and the second heat conducting portion 13b as the heat conducting portion 13 that are connected to the first main surface 11a. In this way, the heat conducting portions 13 are arranged on the second main surface 11b of the substrate 11 in a larger area or in greater numbers than on the first main surface 11a. Therefore, the heat of the heat generating component 22 can be dissipated from the heat dissipation member 31 to the outside of the substrate 11 more efficiently on the second main surface 11b side.

[0069] In the above heat dissipation device, the second heat conductive portion 13b is preferably formed of a core material as a conductive member filled in the hole 15 formed in the substrate 11. In this way, the heat dissipation function of the second heat conductive portion 13b can be further improved.

[0070] However, in the above heat dissipation device, the second heat conductive portion may be formed of an inner wall conductive film 16 as a conductive member covering the inner wall of a hole 15 formed in the substrate 11. In this case, no core material or the like is disposed inside the inner wall conductive film 16 in the hole 15, and the hole is hollow. However, even in this case, the thermal conductivity of the inner wall conductive film 16 ensures a minimum level of thermal conductivity for the second heat conductive portion. Since no core material is provided, such a second heat conductive portion can reduce manufacturing costs by reducing material costs.

[0071] In the above heat dissipation device, the inner layer wiring 14 is preferably arranged so as to connect the first heat conductive portion 13a and the second heat conductive portion 13b. For example, the resin material constituting the board body 12 has difficulty in sufficiently transmitting the heat transmitted from the heat generating component 22 to the first heat conductive portion 13a directly below it to the second heat conductive portion 13b. Therefore, the first heat conductive portion 13a and the second heat conductive portion 13b are connected by the inner layer wiring 14. This makes it possible to easily transmit the heat of the first heat conductive portion 13a to the second heat conductive portion 13b via the inner layer wiring 14. In this way, the heat of the heat generating component 22 can be dissipated to the outside not only from the first heat conductive portion 13a but also from the second heat conductive portion 13b.

[0072] Embodiment 5. FIG. 8 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a fifth embodiment. With reference to FIG. 8, this embodiment has a third heat conductive portion 13c. Specifically, in heat dissipation device 201 of the fifth embodiment in FIG. 5, third heat conductive portion 13c as heat conductive portion 13 is arranged to be sandwiched between heat generating component 22 and first heat conductive portion 13a. Third heat conductive portion 13c is arranged to include a region overlapping heat generating component 22 in a plan view. In FIG. 5, first heat conductive portion 13a entirely overlaps heat generating component 22 in a plan view.

[0073] The third heat conductive portion 13c is, for example, a plate having a rectangular planar shape, and is formed from a metal block of a material having high thermal conductivity, such as copper.

[0074] The third heat conductive portion 13c is disposed at approximately the same position as the solder ball 32 in the Z direction. The third heat conductive portion 13c is joined to the plating film 17a covering the upper part of the hole 15 into which the first heat conductive portion 13c is inserted, by a reflow layer 34. The reflow layer 34 means a layer joined by a reflow process described later. The third heat conductive portion 13c is joined to the bottom surface of the package 23 by a bonding layer 35. The bonding layer 35 is made of a material with high thermal conductivity, in particular, a material with higher conductivity than the solder ball 32.

[0075] Next, a method for bonding heat dissipation device 201 of FIG. 8, particularly between substrate 11 and mounted component 21, will be described with reference to FIG. 9. FIG. 9 is a schematic cross-sectional view showing a bonding step between substrate and mounted component in a manufacturing process of the heat dissipation device of FIG. 8. Referring to FIG. 9, reflow solder 34a is applied onto surface wiring 17 and plating film 17a on first main surface 11a of substrate 11. Reflow solder 34a is a paste-like solder material used for bonding by a reflow process described later. However, reflow solder 34a is not limited to a solder material, and other paste-like conductive materials capable of bonding by a reflow process may be used.

[0076] 9, prior to bonding of the substrate 11 and the mounting component 21, the third thermally conductive portion 13c is bonded by a bonding layer 35 to a position of the mounting component 21 overlapping, for example, with the heat-generating component 22 in a plan view. The third thermally conductive portion 13c is bonded to the bottom surface of the package 23. The bonding layer 35 used for this bonding is made of a material having a higher conductivity than the solder balls 32.

[0077] 9, the mounting component 21 to which the third heat conductive portion 13c and the solder balls 32 are joined is placed on the board 11 to which the reflow solder 34a has been applied. The reflow solder 34a is applied to the surface wiring 17 and plating film 17a of the board 11 in an area that is to overlap the solder balls 32 or the third heat conductive portion 13c in a plan view. With the mounting component 21 placed on the board 11, a commonly known reflow process is performed. As a result, the reflow solder 34a becomes a reflow layer 34, and the board 11 and the mounting component 21 are joined.

[0078] Next, the effects of this embodiment will be described. For example, when the package is a BGA package, the board and the mounted components are connected by solder balls. Therefore, the area of ​​the region that can be thermally connected between the board and the mounted components is limited by the amount and surface area of ​​the solder balls. Therefore, if the amount and surface area of ​​the solder balls are insufficient, the thermal resistance between the board and the mounted components increases. Therefore, it is desirable to minimize the thermal resistance between the two.

[0079] In order to reduce thermal resistance, a solder ball may be made of a solder material containing a metal core or a bonding material with high thermal conductivity, such as silver paste. However, bonding materials with high thermal conductivity are expensive. Therefore, if only solder balls made of the above materials are used for the entire heat dissipation device, the cost will rise. In order to reduce material costs, it is preferable to selectively use the above materials only for solder balls in areas of the heat dissipation device that require particularly high heat dissipation.

[0080] Therefore, in the heat dissipation device according to the disclosure of this embodiment, the third heat conductive portion 13c is sandwiched between the heat generating component 22 and the first heat conductive portion 13a. That is, the third heat conductive portion 13c having a high thermal conductivity is disposed at least directly below the heat generating component 22, i.e., in an area where the amount of heat dissipation is large and overlaps with the heat generating component 22 in a plan view. Therefore, for the solder balls 32 disposed in an area other than the area where the third heat conductive portion 13c is disposed, a material having a lower thermal conductivity and being less expensive than that used in the fourth embodiment can be used. Even in this case, by disposing at least the third heat conductive portion 13c, high heat dissipation performance can be ensured in the entire heat dissipation device 201.

[0081] Furthermore, if the third heat conductive portion 13c has a rectangular plate shape, the joint between the third heat conductive portion 13c and the first heat conductive portion 13a does not need to be spherical like the solder ball 32. In other words, the degree of freedom in the shape of the joint increases. Therefore, by making the joint into a shape with low thermal resistance, the thermal resistance of the joint can be reduced. Therefore, the third heat conductive portion 13c can reduce the thermal resistance of the joint between the third heat conductive portion 13c and the substrate 11. Therefore, high heat dissipation performance can be ensured in the entire heat dissipation device 201.

[0082] Embodiment 6 Fig. 10 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a first example of the sixth embodiment. With reference to Fig. 10, heat dissipation device 301 of the first example of the present embodiment has almost the same configuration as heat dissipation device 101, but a first heat conduction portion 13ad is arranged instead of first heat conduction portion 13a. First heat conduction portion 13ad as a core material is made of copper molybdenum (CuMo). Thus, first heat conduction portion 13ad in the present embodiment contains copper molybdenum.

[0083] FIG. 11 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a second example of the sixth embodiment. Referring to FIG. 11, heat dissipation device 302 according to the second example of the present embodiment has almost the same configuration as heat dissipation device 102, but instead of first heat conductive portion 13a, first heat conductive portion 13ad made of copper molybdenum is arranged. FIG. 12 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a third example of the sixth embodiment. Referring to FIG. 12, heat dissipation device 303 according to the third example of the present embodiment has almost the same configuration as heat dissipation device 201, but instead of first heat conductive portion 13a, first heat conductive portion 13ad made of copper molybdenum is arranged.

[0084] Next, a description will be given of the operation and effect of embodiment 6. By using first thermally conductive portion 13ad containing copper molybdenum as shown in Fig. 10 to Fig. 12, it is possible to further improve heat dissipation compared to first thermally conductive portion 13a made of copper.

[0085] In the heat dissipation devices 301-303 of Figs. 10-12, the core material of the second heat conductive portion 13b may be made of copper as in the fourth and fifth embodiments. However, the second heat conductive portion 13b of the heat dissipation devices 301-303 may also contain copper molybdenum or be made of copper molybdenum as in the first heat conductive portion 13ad. Fig. 13 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a fourth example of the sixth embodiment. Referring to Fig. 13, the heat dissipation device 304 of the fourth example of the present embodiment has almost the same configuration as the heat dissipation device 301, but the core material of the second heat conductive portion 13b is not disposed in the lower non-through hole portion 15 (second hole portion). Fig. 14 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a fifth example of the sixth embodiment. Referring to FIG. 14, a heat dissipation device 305 of a fifth example of this embodiment has almost the same configuration as the heat dissipation device 302, but the core material of the second heat conductive portion 13b is not arranged in the lower non-through hole portion 15 (second hole portion). Since high heat dissipation is ensured by the first heat conductive portion 13ad, the second heat conductive portion around it may be configured as shown in FIGS. 13 and 14, which is only the inner wall conductive film 16 having only the minimum thermal conductivity. Since no core material is provided, the inner wall conductive film 16, which is the second heat conductive portion in the lower non-through hole portion 15 (second hole portion), can reduce the manufacturing cost by reducing the material cost. Also, in FIGS. 13 and 14, the first heat conductive portion 13a similar to the fourth and fifth embodiments may be used instead of the first heat conductive portion 13ad.

[0086] Embodiment 7 FIG. 15 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a first example of the seventh embodiment. The first heat conduction portion 13e of the heat dissipation device 401 is different in shape from the first heat conduction portion 13h or the first heat conduction portion 13i. Here, the first heat conduction portion 13e is different in shape from the first heat conduction portion 13h, but the first heat conduction portion 13i may have the same configuration. With reference to FIG. 15, the heat dissipation device 401 of the first example of this embodiment does not have a non-penetrating hole portion 15 (second hole portion), and only the hole portion 15 (first hole portion) is formed in the substrate 11 from the first main surface 11a to the second main surface 11b. This hole portion 15 is formed in the center in the X direction in FIG. 15, and is formed so as to include an area overlapping with the heat generating component 22 in a plan view. In FIG. 1, only one hole portion 15 (first hole portion) is formed in the center of such a substrate main body 12. Hole 15 has a width gradually increasing along the main surface from first main surface 11a to second main surface 11b, and a cross-sectional area gradually increasing along the XY plane intersecting with the Z direction along which hole 15 extends.

[0087] That is, the inner wall surface of hole 15 extending from first main surface 11a to second main surface 11b extends so as to be inclined with respect to the Z direction. In other words, in the cross-sectional view of Figure 15, the inner wall surface of hole 15 extends in a tapered shape.

[0088] The inside of the hole 15 is filled with a first heat conductive portion 13e as the heat conductive portion 13. The first heat conductive portion 13e is arranged so as to fill almost the entire inside of the hole 15, similar to the first heat conductive portion 13a of the first embodiment. That is, the first heat conductive portion 13e is arranged so as to penetrate the substrate 11, particularly the substrate body 12, from the first main surface 11a to the second main surface 11b. The first heat conductive portion 13e includes a region overlapping with the heat generating component 22 in a planar view. However, since the first heat conductive portion 13e becomes larger toward the bottom in the Z direction, the outside of the first heat conductive portion 13e does not overlap with the heat generating component 22 in a planar view, particularly in the region on the second main surface 11b side. The first heat conductive portion 13e is a core material made of a material with high thermal conductivity such as copper, having a tapered cross-sectional shape similar to the hole 15.

[0089] The first heat conducting portion 13e has a heat dissipation fin formed on the surface opposite to the surface facing the heat generating component 22, similar to the first heat conducting portion h in FIG. 2. More specifically, the first conductive member that is the first heat conducting portion 13e is formed of a portion formed inside the hole portion 15 (first hole portion) and a portion protruding to the outside of the hole portion 15 (first hole portion), similar to the first heat conducting portion 13h. The heat dissipation fin is formed on this portion protruding to the outside. Although not shown here, the first heat conducting portion 13e may be configured such that the heat dissipation member 31 and the first heat conducting portion 13e are fixed by a fastening member such as a screw, similar to the heat conducting portion 13i in FIG. 3. More specifically, the first heat conducting portion 13e may be configured such that the heat dissipation member 31 and the first heat conducting portion 13e are fixed by a fastening member inserted into the hole portion formed in the heat conducting portion 31 and the hole portion formed in the first heat conducting portion 13e.

[0090] The inner layer wiring 14 is partially removed when the hole 15 is formed, and is therefore exposed on at least a part of the inner wall surface of the hole 15. However, an inner wall conductive film 16 may be formed on the inner wall surface. In any case, the first heat conductive portion 13e and the inner layer wiring 14 are at least thermally connected. It is more preferable that the first heat conductive portion 13e and the inner layer wiring 14 are electrically connected.

[0091] In heat dissipation device 401, similarly to heat dissipation device 201, third heat conductive portion 13c as heat conductive portion 13 is disposed between heat generating component 22 and first heat conductive portion 13a so as to be sandwiched therebetween. However, heat dissipation device 401 does not have third heat conductive portion 13c, and substrate 11 and mounted component 21 may be connected by solder balls 32 even in the region where third heat conductive portion 13c is disposed.

[0092] Fig. 16 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a second example of the seventh embodiment. With reference to Fig. 16, heat dissipation device 402 of the second example of the present embodiment is different from heat dissipation device 401 in the following respects. Substrate 11 of heat dissipation device 402 has non-penetrating hole 15 (second hole) formed on the upper side. Hole 15 (first hole) of substrate 11 from first main surface 11a to second main surface 11b has a width along the main surface and a cross-sectional area along an XY plane intersecting with the Z direction in which it extends, which increases stepwise from first main surface 11a to second main surface 11b.

[0093] That is, the inner wall surface of hole 15 extending from first main surface 11a to second main surface 11b extends so as to periodically have a portion extending in the Z direction and a portion bending from the portion to extend along the X direction and the Y direction. In other words, in the cross-sectional view of FIG. 16, the inner wall surface of hole 15 extends in a stepped manner.

[0094] The inside of the hole 15 is filled with a first heat conductive portion 13f as the heat conductive portion 13. The first heat conductive portion 13f is a core material such as copper. The filling manner of the first heat conductive portion 13f into the hole 15 is similar to the filling manner of the first heat conductive portion 13e into the hole 15 in the heat dissipation device 402.

[0095] The conductive member as the first heat conducting portion 13f is also engaged with the substrate 11 by screwing, similar to the first conductive member in FIG. 1. More specifically, the conductive member as the first heat conducting portion 13f has a first screw groove formed on its outer peripheral surface. The hole portion 15 (second hole portion) has a second screw groove formed on its inner peripheral surface. The substrate 11 and the first heat conducting portion 13f are engaged with each other by screwing so that the first screw groove and the second screw groove mesh with each other. Note that, similar to the heat dissipation device 401, the first heat conducting portion 13f may be configured to be inserted into the hole portion 15 by press-fitting, without the first screw groove, as necessary. Furthermore, although not shown here, the first heat conducting portion 13f may be configured to be fixed between the heat dissipation member 31 and the first heat conducting portion 13e by a fastening member such as a screw, similar to the heat conducting portion 13i in FIG. 3. Specifically, the heat dissipation member 31 and the first heat conductive portion 13f may be fixed by a fastening member inserted into a hole formed in the heat dissipation member 31 and a hole formed in the first heat conductive portion 13f. The first heat conductive portion 13f and the inner layer wiring 14 are at least thermally connected to each other.

[0096] That is, the first heat conducting portion 13f has a stepped cross-sectional shape. The first heat conducting portion 13f has a width in the X direction that allows it to face, for example, an upper non-through hole portion 15 (second hole portion) located directly above it in the Z direction. The hole portion 15 closest to the first heat conducting portion 13f among the plurality of non-through holes 15 (second hole portion) faces, in the Z direction, a second region of the first heat conducting portion 13f, which is wider by one step than the narrow first region of the first heat conducting portion 13f that leads to the first main surface 11a. The hole portion 15 farthest from the first heat conducting portion 13f among the plurality of non-through holes 15 (second hole portion) faces, in the Z direction, a third region of the first heat conducting portion 13f, which is wider by one step than the second region. In this way, it is preferable that the width of first heat conducting portion 13f in the X direction increases stepwise depending on the position of non-through hole portion 15 (second hole portion) in the X direction so as to face it.

[0097] Next, referring to FIG. 17 and FIG. 18, the inserting step and the joining step of the first heat conducting part 13e into the hole 15 of the substrate 11 joined to the mounting component 21 of the heat dissipation device 401 of FIG. 15 will be described. FIG. 17 is a schematic cross-sectional view showing the inserting step of the heat conducting part into the hole of the substrate as the first step of the manufacturing process of the heat dissipation device of FIG. 15. Referring to FIG. 17, the substrate 11 and the mounting component 21 are joined via the solder ball 32 by the reflow step as in the step of FIG. 9. At this point, the inside of the hole 15 formed in the substrate 11 is hollow. After the joining, the core material of the first heat conducting part 13e, the uppermost surface of which is coated with, for example, paste-like low-temperature solder 36a, is inserted into the hole 15.

[0098] FIG. 18 is a schematic cross-sectional view showing a bonding step of the heat conductive portion as the second step of the manufacturing process of the heat dissipation device of FIG. 15. Referring to FIG. 18, for example, a reflow step is performed again using low-temperature solder 36a. As a result, low-temperature solder 36a becomes low-temperature solder layer 36, and first heat conductive portion 13e is bonded to the lower surface of third heat conductive portion 13c. As a result, first heat conductive portion 13e is filled in hole 15 of substrate 11. Here, low-temperature solder 36a is used in order to prevent the occurrence of defects such as remelting of reflow solder 34a used for bonding in the previous reflow step during the second reflow step. In other words, low-temperature solder 36a means a solder material having a lower melting point than reflow solder 34a used in the previous reflow step. However, low-temperature solder 36a is not limited to a solder material, and any material can be used as long as it has a lower melting point than reflow solder 34a.

[0099] Although detailed description will be omitted, the process of inserting and bonding first thermally conductive portion 13f in heat dissipation device 402 in FIG. 16 is also performed by basically the same processes as those in FIGS.

[0100] Next, the effects of the present embodiment will be described. The heat dissipation device according to the disclosure of the present embodiment includes a substrate 11 and a heat generating component 22. The heat generating component 22 is disposed on a first main surface 11a of the substrate 11. The substrate 11 includes a heat conducting portion 13 and an inner layer wiring 14. The heat conducting portions 13e and 13f transmit heat generated by the heat generating component 22. The inner layer wiring 14 is formed so as to be connected to the heat conducting portions 13e and 13f within the substrate 11. The heat conducting portions 13e and 13f include an area overlapping with the heat generating component 22 in a plan view, and penetrate the substrate 11 from the first main surface 11a to the second main surface 11b opposite the first main surface 11a. Thermally conductive portions 13e, 13f have a width in a direction along the main surface of substrate 11 and a cross-sectional area in a plane along a direction intersecting the extension direction of thermally conductive portions 13e, 13f that is larger on the second main surface 11b side than on the first main surface 11a side.

[0101] As a result, similar to the fourth embodiment, the area of ​​the portion where heat conductive portions 13e, 13f communicate with second main surface 11b is larger than the area of ​​the portion where heat conductive portions 13e, 13f communicate with first main surface 11a. Therefore, similar to the fourth embodiment, the heat of heat generating component 22 can be dissipated to the outside of substrate 11 more efficiently on the second main surface 11b side.

[0102] In the manufacturing process of the heat dissipation devices 401, 402, particularly if the third heat conductive portion 13c is large, it may not be possible to store it between the substrate 11 and the mounted component 21. In such a case, as in the process of Figures 17 and 18, after the mounted component 21 is mounted on the substrate 11, the heat conductive portions 13e, 13f are inserted into the holes 15 (first holes) of the substrate 11 and joined by low-temperature solder. In this way, the heat dissipation devices 401, 402 having the aspects of Figures 15 and 16 can be provided with high quality.

[0103] Embodiment 8 FIG. 19 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a first example of the eighth embodiment. Referring to FIG. 19, a heat dissipation device 501 according to the first example of the present embodiment has almost the same configuration as the heat dissipation device 100a, but a first heat conduction portion 13ad is arranged instead of the first heat conduction portion 13a. The first heat conduction portion 13ad as a core material is made of copper molybdenum (CuMo). Thus, the first heat conduction portion 13ad in the present embodiment contains copper molybdenum. Here, the first heat conduction portion 13ad is the one whose core material of the first heat conduction portion 13a of the heat dissipation device 100a is made of copper molybdenum (CuMo), but the first heat conduction portion 13ad may be the one whose core material of the first heat conduction portion 13h or the first heat conduction portion 13i is made of copper molybdenum (CuMo).

[0104] The heat dissipation device 501 does not have a non-through hole 15 (second hole), and only the hole 15 (first hole) is formed in the substrate 11 from the first main surface 11a to the second main surface 11b. This hole 15 is formed to include an area overlapping with the heat generating component 22 in a plan view, similar to the hole 15 into which the first heat conducting part 13a of the heat dissipation device 101 or the like is inserted. In FIG. 19, the entire area inside this hole 22 is arranged in the area overlapping with the heat generating component 22 in a plan view. A first heat conducting part 13ad is arranged as the heat conducting part 13 so as to fill almost the entire area inside this hole 15. That is, a core material of the first heat conducting part 13ad containing copper molybdenum or made of copper molybdenum is arranged in the hole 15 formed in the substrate 11 in the manner shown in FIG. 19. First thermally conductive portion 13ad is disposed so as to penetrate substrate 11, particularly substrate body 12, from first main surface 11a to second main surface 11b. First thermally conductive portion 13e includes a region overlapping with heat-generating component 22 in a plan view.

[0105] In the substrate 11, the first heat conductive portion 13ad and the inner layer wiring 14 are at least thermally connected to each other. It is more preferable that the first heat conductive portion 13ad and the inner layer wiring 14 are electrically connected to each other.

[0106] Fig. 20 is a schematic cross-sectional view showing a configuration of a heat dissipation device according to a second example of embodiment 8. Referring to Fig. 20, heat dissipation device 502 of the second example of the present embodiment differs from heat dissipation device 501 in that solder balls 32 are not arranged in the region between substrate 11 and mounted component 21 directly above first thermally conductive portion 13ad.

[0107] Next, the effects of the heat dissipation devices 501 and 502 will be described. These heat dissipation devices include a substrate 11 and a heat generating component 22. The heat generating component 22 is disposed on a first main surface 11a of the substrate 11. The substrate 11 includes a heat conducting portion 13ad and an inner layer wiring 14. The heat conducting portion 13ad transmits heat generated by the heat generating component 22. The inner layer wiring 14 is formed so as to be connected to the heat conducting portion 13ad within the substrate 11. The heat conducting portion 13ad includes a region overlapping with the heat generating component 22 in a plan view, and penetrates the substrate 11 from the first main surface 11a to the second main surface 11b opposite to the first main surface 11a. The first heat conducting portion 13ad includes copper molybdenum.

[0108] In this way, as in embodiment 6, it is possible to obtain a higher heat dissipation property than that of copper by first heat conductive portion 13ad containing copper molybdenum. Therefore, even if solder balls 32 directly below heat-generating component 22 are omitted as in heat dissipation device 502 in Fig. 20, it is possible to ensure heat dissipation from heat-generating component 22 to heat conductive portion 13ad directly below it.

[0109] Fig. 21 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a third example of the eighth embodiment. Referring to Fig. 21, heat dissipation device 503 of the third example of the present embodiment differs from heat dissipation device 501 in that hole 15 does not penetrate substrate 11, but only communicates with first main surface 11a. Therefore, first thermally conductive portion 13gd filled in hole 15 also does not penetrate substrate 11, but only communicates with first main surface 11a. First thermally conductive portion 13gd is a core material containing or made of copper molybdenum.

[0110] 21, the heat dissipation properties of first heat conductive portion 13gd containing copper molybdenum are very high. Therefore, the heat dissipation function from heat generating component 22 to first heat conductive portion 13gd and to heat dissipation member 31 below it can be ensured to a certain degree. This is because first heat conductive portion 13gd has high thermal conductivity.

[0111] FIG. 22 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a fourth example of the eighth embodiment. Referring to FIG. 22, in the heat dissipation device 504 of the fourth example of the present embodiment, the hole 15 is formed in a step shape like the heat dissipation device 402, as compared with the heat dissipation device 501. However, the step shape of the hole 15 is simpler than that of the heat dissipation device 402. While the heat dissipation device 402 has a three-step step shape, the heat dissipation device 504 has a two-step step shape. In the hole 15, a core material of the first heat conduction part 13fd containing copper molybdenum is disposed as in the other examples. With the configuration of FIG. 22, the high thermal conductivity of the first heat conduction part 13fd and the shape in which the area on the second main surface 11b side is larger than that on the first main surface 11a side can ensure high heat dissipation to the heat dissipation member 31 side as in the other examples.

[0112] FIG. 23 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a fifth example of the eighth embodiment. Referring to FIG. 23, in a heat dissipation device 505 according to the fifth example of the present embodiment, the first heat conductive portion 13e of the heat dissipation device 401 is replaced with a core material of the first heat conductive portion 13ed containing or made of copper molybdenum. FIG. 24 is a schematic cross-sectional view showing the configuration of a heat dissipation device according to a sixth example of the eighth embodiment. Referring to FIG. 24, in a heat dissipation device 506 according to the sixth example of the present embodiment, the first heat conductive portion 13f of the heat dissipation device 402 is replaced with a core material of the first heat conductive portion 13fd containing or made of copper molybdenum. Even if the heat conductive portions 13ed and 13fd containing copper molybdenum are used as in FIG. 23 and FIG. 24, high heat dissipation can be ensured as in the other examples of the present embodiment.

[0113] In this embodiment, similarly to the sixth embodiment, a core material of the heat conductive portion 13 containing or made of copper molybdenum may be inserted into the non-penetrating hole portion 15 (second hole portion) as well.

[0114] The features described in each of the above-described embodiments (each example included therein) may be applied in an appropriate combination within a range that is not technically inconsistent.

[0115] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0116] 11 substrate, 11a first main surface, 11b second main surface, 12 substrate body, 13 heat conductive portion, 13a, 13ad, 13e, 13ed, 13fd, 13gd, 13h, 13i first heat conductive portion, 13b second heat conductive portion, 13c third heat conductive portion, 14 inner layer wiring, 15 hole portion, 16 inner wall conductive film, 17 surface wiring, 17a plating film, 21 mounted component, 22 heat generating component, 23 package, 24, 35 bonding layer, 31 heat dissipation member, 32 solder ball, 33 non-conductive heat dissipation sheet, 34 reflow layer, 34a reflow solder, 36 low temperature solder layer, 36a Low temperature solder, 100a, 100b, 100c, 101, 102, 103, 201, 301, 302, 303, 401, 402, 501, 502, 503, 504, 505, 506 Heat dissipation devices.

Claims

1. a mounting component including a heat generating component and a package for accommodating the heat generating component; a substrate including: a first main surface on which a first hole is formed, and on which a surface wiring is formed that is joined by a conductive bonding member to a pattern of a conductive film formed on a bottom surface of the package and electrically connected to the heat generating component; a second main surface opposite to the first main surface; a heat conducting portion that transmits heat generated by the heat generating component and that includes an area overlapping with the heat generating component in a plan view, the heat conducting portion penetrating from the first main surface to the second main surface, the first heat conducting portion being formed by a first conductive member filled in the first hole and connected to the surface wiring; and an inner layer wiring formed inside the heat conducting portion; a heat dissipation device, wherein the first conductive member has a first thread groove formed on its outer peripheral surface, the first hole portion has a second thread groove formed on its inner peripheral surface and the inner peripheral surface is covered with an inner wall conductive film, and the first thread groove and the second thread groove are engaged with each other.

2. The heat dissipation device according to claim 1 , wherein the first heat conducting portion has a heat dissipation fin formed on a surface opposite to a surface facing the heat generating component.

3. a heat dissipation member provided on a surface of the first thermal conductive portion opposite to a surface facing the heat generating component; The heat dissipation device according to claim 1 , wherein the heat dissipation member is fixed to the first heat conductive portion by a fastening member inserted into a hole formed in the heat dissipation member and a hole formed in the first heat conductive portion.

4. 4. The heat dissipation device according to claim 1, further comprising a second heat conductive portion arranged around the first heat conductive portion and spaced apart from the first main surface and / or the second main surface.

5. The heat dissipation device according to claim 4 , wherein the second thermally conductive portion is disposed in communication with the second main surface.

6. 6. The heat dissipation device according to claim 4, wherein a sum of an area of ​​a portion of the first heat conductive portion and the second heat conductive portion as the heat conductive portion that connect to the second main surface is greater than a sum of an area of ​​a portion of the first heat conductive portion and the second heat conductive portion as the heat conductive portion that connect to the first main surface.

7. 7. The heat dissipation device according to claim 4, wherein the second thermal conductive portion is formed by a second conductive member filled in a second hole formed in the substrate.

8. 7. The heat dissipation device according to claim 4, wherein the second thermal conductive portion is formed of a second conductive member covering an inner wall of a second hole formed in the substrate.

9. The heat dissipation device according to claim 4 , wherein the inner layer wiring is disposed so as to connect the first heat conductive portion and the second heat conductive portion.

10. The heat dissipation device according to claim 1 , further comprising a third heat conductive portion sandwiched between the heat generating component and the first heat conductive portion.

11. The heat dissipation device according to claim 1 , wherein the first thermally conductive portion comprises copper molybdenum.

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