JP2017005093A - Substrate heat dissipation structure and method of assembling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate heat dissipation structure and the like which can obtain sufficient heat dissipation performance and can be easily manufactured.SOLUTION: A substrate heat dissipation structure 100 includes a printed wiring board 110, a heat generating component 130, through vias 116, and a heat conductive core 120. The printed wiring board 110 has first and second principal surfaces 111 and 112. The heat generating component 130 is mounted on the first principal surface 111. The through via 116 penetrates between the first and second principal faces 111, 112, and is formed in the printed wiring board 110 such that an opening diameter gradually increases from the first principal surface 111 toward the second principal surface 112. The heat conductive core 120 has thermal conductivity and is formed so as to correspond to the shape of the through via 116. The heat conducting core 120 is inserted into the through via 116 and is thermally connected to the heat generating component 130.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a substrate heat dissipation structure and the like, for example, to a structure that dissipates heat from a heat-generating component mounted on a substrate.

  In recent years, electronic devices have been downsized, and it has become difficult to sufficiently dissipate heat from a heat-generating component mounted on the electronic device using a heat radiating unit (for example, a heat sink). In particular, the contact area between the heat generating component and the heat radiating part cannot be sufficiently ensured, and the heat of the heat generating component cannot be sufficiently radiated by the heat radiating part.

  In recent years, there has been a demand for longer life and maintenance-free electronic devices. However, due to the downsizing of the electronic device, a structure (forced air cooling structure) that forcibly cools the heat of the heat-generating component by a fan cannot be adopted in the electronic device. A structure for efficiently transferring the heat of the heat generating component to the heat radiating portion is also provided in the printed wiring board.

  Hereinafter, an example of a general substrate heat dissipation structure will be described. FIG. 9 is a diagram showing a configuration of a general substrate heat dissipation structure 900. The substrate heat dissipation structure 900 employs a so-called thermal via connection structure.

  As shown in FIG. 9, the substrate heat dissipation structure 900 includes a printed wiring board 910, a heat generating component 930, a heat dissipation part 940, and a heat conductive sheet 950.

  As shown in FIG. 9, the printed wiring board 910 has a first main surface 911 (front surface) and a second main surface 912 (back surface). Further, the printed wiring board 910 is configured by alternately laminating conductive layers 913 and insulating layers 914. A plurality of through vias 916 are formed on the printed wiring board 910 so as to penetrate between the first main surface 911 and the second main surface 912. The plurality of through vias 916 are provided on the first main surface 911 side so as to face the thermal pad 933 provided at the bottom of the heat generating component 930.

  As shown in FIG. 9, the heat generating component 930 is mounted on the first main surface 911 of the printed wiring board 910. At this time, the terminal 932 of the heat generating component 930 is connected to the conductive layer 913 a formed on the first main surface 911 by the solder H. Further, the thermal pad 933 of the heat generating component 930 is thermally connected to each of the plurality of through vias 916 by solder H.

  As shown in FIG. 9, the heat radiating portion 940 includes a plurality of fins 941. The heat dissipating part 940 is thermally connected to each of the plurality of through vias 916 via the heat conductive sheet 950 on the second main surface 912 side. Instead of the heat conductive sheet 950, heat conductive grease may be used.

  In this way, the thermal pad 933 and the heat radiating portion 940 of the heat generating component 930 are thermally connected via each of the plurality of through vias 916 and the heat conductive sheet 950. The heat of the heat generating component 930 is transmitted to the heat radiating unit 940 via each of the plurality of through vias 916 and the heat conductive sheet 950. The heat radiating unit 940 radiates the heat of the heat-generating component 930 that has received the heat.

  Next, another example of the general substrate heat dissipation structure 900A will be described. FIG. 10 is a diagram showing a configuration of a general substrate heat dissipation structure 900A.

  As shown in FIG. 10, the substrate heat dissipation structure 900 </ b> A includes a printed wiring board 910 </ b> A, a heat conductive core 920, a heat generating component 930, a heat dissipation portion 940, and a heat conductive sheet 950.

  As shown in FIG. 10, the heat conducting core 920 is formed in a cylindrical shape. For example, copper is used as the material of the heat conductive core 920. The heat conductive core 920 penetrates between the first main surface 911 and the second main surface 912 of the printed wiring board 910. Further, the upper end portion of the heat conductive core 920 is provided on the first main surface 911 side so as to face the thermal pad 933 of the heat generating component 930. The upper end portion of the heat conducting core 920 is thermally connected to the thermal pad 933 of the heat generating component 930 by solder H. The heat conducting core 920 is incorporated in advance when the printed wiring board 910 is manufactured. The printed wiring board 910 in which the heat conducting core 920 made of copper is incorporated is also called a copper inlay board.

  As shown in FIG. 10, the heat radiating portion 940 is thermally connected to the heat conductive core 920 via the heat conductive sheet 950 on the second main surface 912 side.

  In this way, the thermal pad 933 and the heat radiating portion 940 of the heat generating component 930 are thermally connected via the heat conductive core 920 and the heat conductive sheet 950. The heat of the heat generating component 930 is transmitted to the heat radiating unit 940 via the heat conductive core 920 and the heat conductive sheet 950. The heat radiating unit 940 radiates the heat of the heat-generating component 930 that has received the heat.

  In addition, the technique relevant to this invention is disclosed by patent document 1 and 2, for example.

Japanese Patent Laid-Open No. 03-083391 Japanese Patent Laid-Open No. 03-283675

  However, in the substrate heat dissipation structure shown in FIG. 9, the heat conductivity of the heat generating component 930 is not sufficiently transmitted to the heat dissipation part 940 through the plurality of through vias 916 and the like because the thermal conductivity of the through via 916 is low. It was. For this reason, sufficient heat dissipation performance could not be obtained.

  In the board heat dissipation structure shown in FIG. 10, the heat of the thermal component 930 is transmitted to the heat dissipation unit 940 through the heat conductive core 920 and the like. For this reason, the heat dissipation performance of the substrate heat dissipation structure shown in FIG. 10 is higher than that of the substrate heat dissipation structure shown in FIG. However, the production of the printed wiring board 910 (copper inlay board) in which the heat conducting core 920 made of copper is incorporated requires a special process, and thus has a problem that it cannot be easily produced.

  This invention is made | formed in view of such a situation, and the objective of this invention is providing the board | substrate heat dissipation structure etc. which can be manufactured easily while obtaining sufficient heat dissipation performance.

  The substrate heat dissipation structure of the present invention has first and second main surfaces, and a heat generating component passes between the first main surface and the substrate on which the heat generating component is mounted. And a through via formed in the substrate so that the opening diameter gradually increases from the first main surface to the second main surface, and has a thermal conductivity and has a shape of the through via. A heat conductive core is formed correspondingly, inserted into the through via, and thermally connected to the heat generating component.

  The method for assembling the substrate heat dissipation structure of the present invention penetrates between the first and second main surfaces of the substrate, and the opening diameter gradually increases from the first main surface toward the second main surface. As described above, the through via forming step for forming the through via on the substrate, the first solder applying step for applying solder to the second main surface, and thermal conductivity, corresponding to the shape of the through via In the first solder application step, after the heat conductive core mounting step of inserting the heat conductive core formed so as to be inserted into the through via, the first solder applying step, and the heat conductive core mounting step, Heat is applied to the applied solder and melted to fix the heat conductive core to the through via, and after the heat conductive core fixing step, solder is applied to the first main surface. Apply After the second solder application step and the second solder application step, the solder applied in the second solder application step is heated and melted to be thermally connected to the heat conducting core. A heating component mounting step of mounting the heating component on the first main surface.

  According to the substrate heat dissipation structure and the like according to the present invention, sufficient heat dissipation performance can be obtained and the substrate can be easily manufactured.

It is a figure which shows the structure of the board | substrate thermal radiation structure in the 1st Embodiment of this invention. It is a figure for demonstrating the assembly method of the board | substrate thermal radiation structure in the 1st Embodiment of this invention. It is a figure for demonstrating the assembly method of the board | substrate thermal radiation structure in the 1st Embodiment of this invention. It is a figure for demonstrating the assembly method of the board | substrate thermal radiation structure in the 1st Embodiment of this invention. It is a figure for demonstrating the assembly method of the board | substrate thermal radiation structure in the 1st Embodiment of this invention. It is a figure for demonstrating the assembly method of the board | substrate thermal radiation structure in the 1st Embodiment of this invention. It is a figure for demonstrating the assembly method of the board | substrate thermal radiation structure in the 1st Embodiment of this invention. It is a figure for demonstrating the assembly method of the board | substrate thermal radiation structure in the 2nd Embodiment of this invention. It is a figure which shows the structure of a general board | substrate heat dissipation structure. It is a figure which shows the structure of a general board | substrate heat dissipation structure. It is a figure for demonstrating the assembly method of a general board | substrate heat dissipation structure.

<First Embodiment>
A configuration of the substrate heat dissipation structure 100 in the embodiment of the present invention will be described.

  As shown in FIG. 1, the board heat dissipation structure 100 includes a printed wiring board 110, a heat conductive core 120, a heat generating component 130, a heat dissipation part 140, and a heat conductive sheet 150. The printed wiring board 110 corresponds to the board of the present invention.

  As shown in FIG. 1, the printed wiring board 110 has a first main surface 111 (front surface) and a second main surface 112 (back surface). The printed wiring board 110 is configured by alternately laminating conductive layers 113 and insulating layers 114. A part of the conductive layer 113a on the first main surface 111 side is exposed, and a part other than the conductive layer 113a is covered with an insulating solder resist 115. The solder resist 115 is applied to an area where the solder H is not desired to be attached. As shown in FIG. 1, the terminal 132 and the thermal pad 133 of the heat generating component 130 are connected to the exposed part of the conductive layer 113 a on the first main surface 111 side by solder H.

  Further, as shown in FIG. 1, the through via 116 penetrates between the first main surface 111 and the second main surface 112 of the printed wiring board 110 and has an opening diameter from the first main surface 111 to the first main surface 111. 2 is formed on the printed wiring board 110 in a tapered shape so as to gradually increase toward the second main surface 112. A conductive film 116 a is formed on the inner wall surface of the through via 116. A conductive film 116 a is also formed on the outer periphery of the through via 116 in the first main surface 111. The conductive film 116a on the first main surface 111 is a part of the conductive layer 113a. Further, a conductive film 116 a is also formed on the outer peripheral portion of the through via 116 in the second main surface 112. For example, copper plating is used to form the conductive film 116a.

  As shown in FIG. 1, the heat conductive core 120 is formed to correspond to the shape of the through via 116. That is, the heat conducting core 120 is formed in a tapered shape so that the outer peripheral diameter gradually increases from the first main surface 111 toward the second main surface 112. Moreover, the heat conductive core 120 has heat conductivity. The heat conductive core 120 is inserted into the through via 116 and fixed to the through via 116 with solder H. Further, the heat conducting core 120 is thermally connected to the thermal pad 133 of the heat generating component 130.

  As shown in FIG. 1, the heat generating component 130 is mounted on the first main surface 111. The heat generating component 130 is an electronic component that generates heat when activated. The heat generating component 130 is, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or an MCM (Multi-chip Module: integrated circuit).

  As shown in FIG. 1, the heat generating component 130 includes a heat generating component main body 131, a terminal 132, and a thermal pad 133. The heat generating component main body 131 has an insulating housing, and houses an electronic circuit or the like for exhibiting the function of the heat generating component 130 in the housing. As shown in FIG. 1, the terminal 132 is provided so as to extend from the heat generating component main body 131. The terminal 132 has conductivity. As shown in FIG. 1, the thermal pad 133 is provided at the bottom of the heat generating component main body 131. More specifically, the thermal pad 133 is provided so as to face the upper end surface (the upper surface in FIG. 1) of the heat conductive core 120 exposed on the first main surface 111. The thermal pad 133 has thermal conductivity.

  As shown in FIG. 1, the heat radiating part 140 is attached on the second main surface 112 of the printed wiring board 110. The heat radiation part 140 is also called a heat sink. The heat dissipation part 140 has thermal conductivity. For example, copper or a copper alloy is used as the material of the heat radiation unit 140. The heat radiating unit 140 has a plurality of heat radiating fins 141. As shown in FIG. 1, the plurality of heat radiating fins 141 are formed so as to extend in a direction away from the second main surface 112 of the printed wiring board 110. The heat radiating part 140 is thermally connected to the heat conducting core 120. In the example of FIG. 1, the heat radiating unit 140 is thermally connected to the heat conductive core 120 via the heat conductive sheet 150. The heat radiating unit 140 receives the heat of the heat generating component 130 via the heat conducting core 120 and radiates this heat to the outside air. In the example of FIG. 1, the heat radiating unit 140 receives the heat of the heat generating component 130 via the heat conductive core 120 and the heat conductive sheet 150 and radiates this heat to the outside air.

  As shown in FIG. 1, the heat conductive sheet 150 is provided between the heat radiation part 140 and the second main surface 112. The heat conductive sheet 150 has heat conductivity. As a material of the heat conductive sheet 150, for example, acrylic having thermal conductivity is used. The heat conductive sheet 150 thermally connects the heat conductive core 130 and the heat radiating unit 140. Since the heat conductive sheet 150 generally has elasticity, the unevenness of the second main surface 112 of the printed wiring board 110 can be absorbed. That is, since the heat conductive sheet 150 has elasticity, the heat conductive sheet 150 can be brought into close contact with the second main surface 112 even when the second main surface 112 of the printed wiring board 110 is uneven. .

  Instead of the heat conductive sheet 150, heat conductive grease may be used. Thermally conductive grease is formed by uniformly dispersing metal or metal oxide particles having high thermal conductivity in grease such as modified silicon. Modified silicon refers to silicon whose viscosity does not change much from room temperature to a certain high temperature. The heat conduction grease is also called heat radiation grease.

  Next, a method for assembling the substrate heat dissipation structure 100 will be described. 2-7 is a figure for demonstrating the assembly method of the board | substrate thermal radiation structure 100. FIG. In the method for assembling the substrate heat dissipation structure 100, a normal SMT (surface mounting technology) process is used. Note that SMT generally refers to a technique of soldering surface mount electronic components or the like to a printed wiring board.

FIGS. 2A to 2C are diagrams for explaining a process of forming the through via 116. The steps described in FIGS. 2A to 2C correspond to the through via forming step of the present invention. For convenience, the conductive layer 113a and the solder resist 115 are omitted in FIGS. 2 (a) to 2 (c).
As shown in FIG. 2A, first, a printed wiring board 110 in which conductive layers 113 and insulating layers 114 are alternately stacked, and a tapered drill D are prepared. Next, as shown in FIG. 2B, a through hole H is formed in the printed wiring board 110 using a drill D. At this time, the through hole H is formed in the printed wiring board 110 in a tapered shape so that the opening diameter gradually increases from the first main surface 111 toward the second main surface 112. Then, a conductive film 116a is formed on the inner wall surface of the through hole H by copper plating or the like. Also, a conductive film 116a is formed on the outer peripheral portion of the through hole H in the first main surface 111 by copper plating or the like. Further, a conductive film 116 a is formed on the outer peripheral portion of the through hole H in the second main surface 112 by copper plating or the like. Thereby, the through via 116 is formed in the printed wiring board 110.

  Next, as shown in FIG. 3, solder H is applied on the second main surface 112 of the printed wiring board 110. FIG. 3 is a diagram for explaining a process of applying solder H onto the second main surface 112 of the printed wiring board 110. The process illustrated in FIG. 3 corresponds to the first solder application step of the present invention.

  Specifically, as shown in FIG. 3, the solder mask M1 is attached to the second main surface 112 to be reflowed first. The solder mask M1 has a plurality of openings. These openings are provided at locations where the solder H is to be printed. In a state where the solder mask M1 is attached to the second main surface 112, paste-like solder H is applied onto the second main surface 112. At this time, in order to secure the amount of solder H necessary to fix the heat conducting core 120 in the through via 116 with the solder H, the paste-like solder H is also printed on the solder resist 115. Then, the solder mask M1 is removed from the second main surface 112.

  Next, as shown in FIG. 4, the heat conducting core 120 is inserted into the through via 116. FIG. 4 is a diagram for explaining a process of inserting the heat conductive core 120 into the through via 116 of the printed wiring board 110. In addition, the process demonstrated by FIG. 4 respond | corresponds to the heat conductive core attachment step of this invention.

  Specifically, as shown in FIG. 4, with the printed wiring board 110 placed with the second main surface 112 facing upward, the component core mounting machine, tweezers, or the like are used to heat the core 120. Insert into the through via 116. At this time, as shown in FIG. 4, the heat conductive core 120 is inserted into the through via 116 in accordance with the tapered shape of the through via 116. Thereby, even if the heat conductive core 120 is inserted into the through via 116, the heat conductive core 120 can be prevented from dropping from the printed wiring board 110.

  Here, a process of inserting the heat conductive core 920 into the through via 916 in a general assembly method of the substrate heat dissipation structure 900A (see FIG. 10) will be described. FIG. 11 is a diagram for explaining a method of assembling a general substrate heat dissipation structure. More specifically, FIG. 11 is a diagram for explaining a process of inserting the heat conductive core 920 into the through via 916 of the printed wiring board 910.

  As shown in FIG. 11, with the printed wiring board 910 placed with the second main surface 912 facing up, the heat conducting core 920 is placed in the through via 916 using an automatic component mounting machine or tweezers. insert. At this time, since the heat conductive core 920 is formed in a cylindrical shape, when the heat conductive core 920 is inserted into the through via 916, the heat conductive core 920 falls from the printed wiring board 910. Therefore, the heat conductive core 920 could not be attached to the printed wiring board 910.

  Next, the heat conducting core 120 is fixed in the through via 116 with solder H. FIG. 5 is a diagram for explaining a process of fixing the heat conductive core 120 to the through via 116. As shown in FIG. 5, by applying heat to the solder H applied to the printed wiring board 110 by reflow, the solder H applied in the process described with reference to FIG. 3 is melted. As a result, the solder H printed on the solder resist 115 is sucked between the tapered heat conductive core 120 and the through via 116. Then, the printed wiring board 110 is cooled. Thereby, the paste-like solder H is solidified, and the heat conductive core 120 is fixed in the through via 116 by the solder H.

  Next, as shown in FIG. 6, solder H is applied on the first main surface 111 of the printed wiring board 110. FIG. 6 is a diagram for explaining a process of applying solder H onto the first main surface 111 of the printed wiring board 110. Note that the process illustrated in FIG. 6 corresponds to the second solder application step of the present invention.

  Specifically, as shown in FIG. 6, the solder mask M2 is attached to the first main surface 111 that is reflowed for the second time. The solder mask M2 has a plurality of openings, like the solder mask M1. These openings are provided at locations where the solder H is to be printed. With the solder mask M2 attached to the first main surface 111, paste solder H is applied onto the first main surface 111. Then, the solder mask M2 is removed from the second main surface 112. As a result, the solder H is printed in the opening area of the solder mask M2.

  Next, as shown in FIG. 7, the heat generating component 130 is mounted on the first main surface 111 of the printed wiring board 110 with the solder H. FIG. 7 is a diagram for explaining a process of attaching the heat generating component 130 and the heat radiating portion 140 onto the printed wiring board 110. The process shown in FIG. 7 corresponds to the heating component mounting step and the heat dissipation component mounting step of the present invention.

  As shown in FIG. 7, with the heat generating component 130 mounted on the first main surface 111, heat is applied to the solder H applied to the printed wiring board 110 by reflow, and the process described in FIG. Melt the applied solder H. At this time, the tip end side of the terminal 132 of the heat generating component 130 is disposed on the conductive layer 132 a exposed on the first main surface 111. Further, the thermal pad 133 of the heat generating component 130 is disposed so as to face the end surface of the heat conducting core 120. Thereby, the heat conductive core 120 and the thermal pad 133 are thermally connected by the solder H. Further, the terminal 132 and the conductive layer 113a are electrically connected. Then, the printed wiring board 110 is cooled. Thereby, the paste-like solder H is solidified, and the heat generating component 130 is fixed to the printed wiring board 110.

  As shown in FIG. 7, the heat radiating portion 140 is attached on the second main surface 112 of the printed wiring board 110. That is, the heat dissipating component 140 having heat conductivity is mounted on the second main surface 112 so as to be thermally connected to the heat conducting core 120. At this time, a heat conductive sheet 150 (or heat radiation grease) having heat conductivity may be provided between the heat radiation portion 140 and the second main surface 112.

  The assembly method of the substrate heat dissipation structure 100 has been described with reference to FIGS.

  As described above, the substrate heat dissipation structure 100 according to the first embodiment of the present invention includes the printed wiring board 110, the through via 116, and the heat conductive core 120. The printed wiring board 110 has first and second main surfaces 111 and 112, and the heat generating component 130 is mounted on the first main surface 111. The through via 116 penetrates between the first main surface 111 and the second main surface 112, and the printed wiring board has an opening diameter that gradually increases from the first main surface 111 toward the second main surface 112. 110 is formed. The thermal conductive core 120 has thermal conductivity and is formed to correspond to the shape of the through via 116. The heat conducting core 120 is inserted into the through via 116 and thermally connected to the heat generating component 130.

  As described above, the through via 116 penetrates between the first and second main surfaces 111 and 112 so that the opening diameter gradually increases from the first main surface 111 toward the second main surface 112. Formed on the printed wiring board 110. Further, the heat conductive core 120 has heat conductivity and is formed so as to correspond to the shape of the through via 116. The heat conducting core 120 is inserted into the through via 116 and thermally connected to the heat generating component 130.

  At this time, the shapes of the through via 116 and the heat conductive core 120 correspond to each other, and the opening diameter of the through via 116 or the outer peripheral diameter of the heat conductive core 120 changes from the first main surface 111 to the second main surface 112. It is formed to gradually increase as it goes. For this reason, the heat conductive via 120 can be attached to the printed wiring board 110 only by inserting the heat conductive via 120 into the through via 116 with the second main surface 112 directed vertically upward. When the heat conductive via 120 is inserted into the through via 116, the heat conductive core 120 can be prevented from falling from the printed wiring board 110.

  On the other hand, the board heat dissipation structure shown in FIG. 10 requires a special process for manufacturing the printed wiring board 910 (copper inlay board) in which the heat conductive core 920 is incorporated, and thus cannot be easily manufactured. There was a problem. In particular, a special process such as press-fitting the heat conductive core 920 into the printed wiring board 910 is required. The substrate heat dissipation structure 100 can be manufactured more easily than the substrate heat dissipation structure 900A shown in FIG.

  In the substrate heat dissipation structure 100, the heat conductive core 120 having thermal conductivity is inserted into the through via 116 and thermally connected to the heat generating component 130. In contrast, in the substrate heat dissipation structure 900 shown in FIG. 9, the heat conductivity of the through via 916 is low, so that the heat of the heat generating component 930 is sufficiently supplied to the heat dissipation portion 940 via the plurality of through vias 916 and the like. It was not told. In the substrate heat dissipation structure 100, the heat of the heat generating component 130 can be received via the heat conductive core 120 having thermal conductivity, and this heat can be transmitted to the heat dissipation unit 140. Therefore, the substrate heat dissipation structure 100 can obtain a sufficient heat dissipation performance as compared with the substrate heat dissipation structure 900 shown in FIG.

  As described above, according to the substrate heat dissipation structure 100 in the first embodiment of the present invention, it is possible to obtain sufficient heat dissipation performance and easily manufacture.

  Further, the substrate heat dissipation structure 100 can be manufactured more easily than the substrate heat dissipation structure 900A shown in FIG. 10, and thus the manufacturing cost can be reduced.

  Unlike the substrate heat dissipation structure 900 shown in FIG. 9, the substrate heat dissipation structure 100 does not require a special process such as press-fitting the heat conductive core 920 into the printed wiring board 910. Further, the substrate heat dissipation structure 100 can be efficiently assembled only by the normal SMT process. For this reason, in the board | substrate heat dissipation structure 100, compared with the board | substrate heat dissipation structure 900 shown in FIG. 9, a manufacturing yield is good and manufacturing cost can also be reduced.

  In the substrate heat dissipation structure 100 according to the first embodiment of the present invention, the heat generating component 130 and the heat conductive core 120 are connected by solder H. Thereby, the heat-emitting component 130 and the heat conductive core 120 can be reliably thermally connected.

  The substrate heat dissipation structure 100 according to the first embodiment of the present invention includes a heat dissipation part 140. The heat radiating part 140 has thermal conductivity, is attached on the second main surface 112, and is thermally connected to the heat conductive core 120. The heat radiating unit 140 receives the heat of the heat generating component 130 via the heat conducting core 120 and radiates this heat. Thereby, the heat of the heat generating component 130 can be efficiently radiated using the heat radiating portion 130.

  The substrate heat dissipation structure 100 according to the first embodiment of the present invention includes a heat conductive sheet 150 or heat dissipation grease. The thermal conductive sheet 150 or the thermal radiation grease has thermal conductivity and is provided between the thermal radiation part 140 and the second main surface 112. The heat conductive sheet 150 or the heat radiating grease thermally connects the heat conductive core 120 and the heat radiating portion 140. Thereby, the unevenness | corrugation of the 2nd main surface 112 of the printed wiring board 110 can be absorbed with the heat conductive sheet 150 or thermal radiation grease. Therefore, even when the second main surface 112 of the printed wiring board 110 is uneven, the heat conductive sheet 150 can be brought into close contact with the second main surface 112.

  In addition, the substrate heat dissipation structure assembly method according to the first embodiment of the present invention includes a through via forming step, a first solder application step, a heat conductive core mounting step, a heat conductive core fixing step, and a second. A solder application step and a heat generating component mounting step.

  In the through via forming step, the first and second main surfaces 111 and 112 of the printed wiring board 110 are penetrated, and the opening diameter gradually increases from the first main surface 111 toward the second main surface 112. Thus, the through via 120 is formed in the printed wiring board 110. In the first solder application step, solder H is applied to the second main surface 112. In the heat conductive core attaching step, the heat conductive core 120 having heat conductivity and formed so as to correspond to the shape of the through via 116 is inserted into the through via 116. In the heat conduction core fixing step, the heat conduction core 120 is penetrated by applying heat to the solder H applied in the first solder application step and melting it after the first solder application step and the heat conduction core attachment step. Fix to the via 116. In the second solder application step, the solder H is applied to the first main surface 111 after the thermally conductive core fixing step. In the heat generating component mounting step, after the second solder application step, the solder H applied in the second solder application step is melted by applying heat so as to be thermally connected to the heat conductive core 120. The heat generating component 130 is mounted on the first main surface 111.

  Even by such a method for assembling the substrate heat dissipation structure, the same effects as those of the substrate heat dissipation structure 100 described above can be obtained.

  Moreover, the method for assembling the board heat dissipation structure in the first embodiment of the present invention further includes a heat dissipation component mounting step. In the heat dissipating component mounting step, the heat dissipating component 140 having heat conductivity is mounted on the second main surface 112 so as to be thermally connected to the heat conducting core 120 after the heat generating component mounting step. Even by such a method for assembling the substrate heat dissipation structure, the same effects as those of the substrate heat dissipation structure 100 described above can be obtained.

  In the method for assembling the substrate heat dissipation structure according to the first embodiment of the present invention, in the heat dissipation component mounting step, the heat conductive sheet 150 or the heat dissipation grease having thermal conductivity is applied to the heat dissipation portion 140 and the second main surface 112. Provide between. Even by such a method for assembling the substrate heat dissipation structure, the same effects as those of the substrate heat dissipation structure 100 described above can be obtained.

<Second Embodiment>
The configuration of the substrate heat dissipation structure in the second embodiment of the present invention will be described. The board heat dissipation structure in the second embodiment of the present invention is similar to the first embodiment in that the printed wiring board 110A, the heat conductive core 120A, the heat generating component 130, the heat radiating portion 140, and the heat conductive sheet. 150.

  Here, in the substrate heat dissipation structure in the second embodiment of the present invention, the configuration of the heat conductive core 120A and the printed wiring board 110A is the same as that of the heat conductive core 120 and the printed circuit board in the substrate heat dissipation structure in the first embodiment of the present invention. Different from the wiring board 110. Here, the configuration of the heat conductive core 120A and the printed wiring board 110A will be mainly described.

  FIG. 8 is a diagram for explaining a method of assembling the substrate heat dissipation structure in the second embodiment of the present invention. FIG. 8 corresponds to FIG. 4 used in the description of the first embodiment.

  As shown in FIG. 8, the through via 116 </ b> A of the printed wiring board 110 </ b> A penetrates between the first main surface 111 and the second main surface 112 of the printed wiring board 110 on the first main surface 111 side. In addition, the printed wiring board 110 </ b> A is formed in a tapered shape so that the opening diameter gradually increases from the first main surface 111 toward the second main surface 112.

  In other words, in the substrate heat dissipation structure 100 according to the first embodiment, the through via 116 extends from the first main surface 111 to the second main surface 112 so that the opening diameter extends from the first main surface 111 to the first main surface 111. The printed wiring board 110 </ b> A is tapered so as to gradually increase toward the second main surface 112. On the other hand, in the substrate heat dissipation structure in the second embodiment, the through via 116A has an opening diameter from the first main surface 111 to the second main surface 112 only on the first main surface 111 side. It is formed on the printed wiring board 110A in a tapered shape so as to gradually increase as the time increases. That is, the taper formation region of the through via 116 is formed over the entire area from the first main surface 111 to the second main surface 112. On the other hand, the through via 116A is formed only on the first main surface 111 side. In this respect, the substrate heat dissipation structure 100 is different from the substrate heat dissipation structure in the second embodiment.

  Similar to the substrate heat dissipation structure 100 in the first embodiment, a conductive film 116Aa is formed on the inner wall surface of the through via 116A. A conductive film 116Aa is also formed on the outer periphery of the through via 116A in the first main surface 111. Note that the conductive film 116Aa on the first main surface 111 is a part of the conductive layer 113a. Further, a conductive film 116Aa is also formed on the outer peripheral portion of the through via 116A in the second main surface 112. For example, copper plating is used to form the conductive film 116Aa.

  As shown in FIG. 8, the heat conductive core 120A is formed to correspond to the shape of the through via 116A. That is, the heat conducting core 120A is formed in a tapered shape so that the outer peripheral diameter gradually increases from the first main surface 111 toward the second main surface 112 only on the first main surface 111 side. Yes. Further, the heat conductive core 120A has heat conductivity. The heat conducting core 120A is inserted into the through via 116A and thermally connected to the thermal pad 133 of the heat generating component 130.

  Heretofore, the configuration of the substrate heat dissipation structure in the second embodiment of the present invention has been described.

  Next, a method for assembling the substrate heat dissipation structure in the second embodiment of the present invention will be described. The method of assembling the substrate heat dissipation structure in the second embodiment of the present invention is the same as that described with reference to FIGS. 2 to 7 in the first embodiment.

  That is, a through hole is formed in the printed wiring board 110 by using a drill in the same manner as described with reference to FIGS. However, unlike the first embodiment, the through hole has an opening diameter that gradually increases from the first main surface 111 toward the second main surface 112 only on the first main surface 111 side. In addition, it is formed on the printed wiring board 110 in a tapered shape. Then, a conductive film 116Aa is formed on the inner wall surface of the through hole by copper plating or the like. Also, a conductive film 116Aa is formed on the outer peripheral portion of the through hole in the first main surface 111 by copper plating or the like. Further, a conductive film 116Aa is formed on the outer peripheral portion of the through hole in the second main surface 112 by copper plating or the like. Thereby, the through via 116 </ b> A is formed in the printed wiring board 110.

  Next, solder is applied onto the second main surface 112 of the printed wiring board 110A in the same manner as described with reference to FIG.

  Next, referring to FIG. 8, the heat conducting core 120 </ b> A is inserted into the through via 116 </ b> A by using an automatic component mounting machine, tweezers, or the like in the same manner as described with reference to FIG. 4. At this time, as shown in FIG. 8, the thermal conductive core 120A is inserted into the through via 116A in accordance with the tapered shape of the through via 116A. Thereby, even if the heat conductive core 120A is inserted into the through via 116A, the heat conductive core 120A can be prevented from dropping from the printed wiring board 110A.

  Next, similarly to the content described with reference to FIG. 5, the solder is melted by applying heat to the solder applied to the printed wiring board 110A by reflow. Thereby, the solder printed on the solder resist 115 is sucked between the tapered heat conductive core 120A and the through via 116A. Then, the printed wiring board 110A is cooled. As a result, the paste-like solder is solidified, and the heat conducting core 120A is fixed in the through via 116A by the solder.

  Next, in the same manner as described with reference to FIG. 6, solder is applied on the first main surface 111 of the printed wiring board 110A.

  Next, in the same manner as described with reference to FIG. 7, heat is applied by reflow to the solder applied to the printed wiring board 110 </ b> A in a state where the heat generating component 130 is mounted on the first main surface 111. To melt. At this time, the tip end side of the terminal 132 of the heat generating component 130 is disposed on the conductive layer 132 a exposed on the first main surface 111. Further, the thermal pad 133 of the heat generating component 130 is disposed so as to face the end face of the heat conducting core 120A. Thereby, the heat conductive core 120A and the thermal pad 133 are thermally connected by the solder. Further, the terminal 132 and the conductive layer 113a are electrically connected. Then, the printed wiring board 110A is cooled. Thereby, the paste-like solder is solidified and the heat generating component 130 is fixed to the printed wiring board 110A.

  Similar to the contents described with reference to FIG. 7, the heat dissipating component 140 having heat conductivity is mounted on the second main surface 112 so as to be thermally connected to the heat conducting core 120 </ b> A. At this time, a heat conductive sheet 150 (or heat radiation grease) having heat conductivity may be provided between the heat radiation portion 140 and the second main surface 112.

  In the above, the assembly method of the board | substrate heat dissipation structure in the 2nd Embodiment of this invention was demonstrated.

  As described above, in the substrate heat dissipation structure in the second embodiment of the present invention, the through via 120A penetrates between the first and second main surfaces 111 and 112. Further, the through via 120A is formed on the printed wiring board 110A so that the opening diameter gradually increases from the first main surface 111 toward the second main surface 112 on the first main surface 111 side. Yes. Even if it is such a structure, there can exist an effect similar to the board | substrate thermal radiation structure 100 in 1st Embodiment.

  That is, the shapes of the through via 116A and the heat conductive core 120A correspond to each other, and the opening diameter of the through via 116A or the outer peripheral diameter of the heat conductive core 120A is the first main surface 111 side on the first main surface 111 side. The first main surface 112 is formed so as to gradually increase from the first to the second main surface 112. For this reason, the heat conductive via 120A can be attached to the printed wiring board 110A only by inserting the heat conductive via 120A into the through via 116A with the second main surface 112 directed vertically upward. When the heat conductive via 120A is inserted into the through via 116A, the heat conductive core 120A can be prevented from falling from the printed wiring board 110A.

  In addition, the thermal conductive core 120A having thermal conductivity is inserted into the through via 116A and thermally connected to the heat generating component 130. In the substrate heat dissipation structure according to the second embodiment of the present invention, the heat of the heat generating component 130 can be received through the heat conductive core 120A having thermal conductivity, and this heat can be transmitted to the heat dissipation unit 140.

  As described above, according to the substrate heat dissipation structure in the second embodiment of the present invention, it is possible to obtain a sufficient heat dissipation performance and easily manufacture the substrate.

  In the method for assembling the substrate heat dissipation structure according to the second embodiment of the present invention, in the through via forming step, the first main surface 111 side passes through between the first and second main surfaces 111 and 112. Then, the through via 116 is formed in the printed wiring board 110 so that the opening diameter gradually increases from the first main surface 111 toward the second main surface 112.

  Even by such a method for assembling the substrate heat dissipation structure, the same effects as those of the substrate heat dissipation structure 100 described above can be obtained.

  The present invention has been described above based on the embodiment. The embodiment is an exemplification, and various modifications, increases / decreases, and combinations may be added to the above-described embodiments without departing from the gist of the present invention. It will be understood by those skilled in the art that modifications to which these changes, increases / decreases, and combinations are also within the scope of the present invention.

110, 110A Printed wiring board 111 First main surface 112 Second main surface 113, 113a Conductive layer 114 Insulating layer 115 Solder resist 116, 116A Through-via 116a, 116Aa Conductive film 120, 120A Thermal conductive core 130 Heat generating component 131 Heat generation Component body 132 Terminal 133 Thermal pad 140 Heat radiation part 141 Heat radiation fin 150 Thermal conductive sheet 910 Printed wiring board 911 First main surface 912 Second main surface 913, 913a Conductive layer 914 Insulating layer 915 Solder resist 916 Through via 920 Thermal conductivity Core 930 Heat generating component 931 Heat generating component main body 932 Terminal 933 Thermal pad 940 Heat dissipating part 941 Heat dissipating fin 950 Thermal conductive sheet 100, 900, 900A Substrate heat dissipating structure H Solder M1, M2 Solder mask

Claims (9)

A substrate having first and second main surfaces, on which a heat generating component is mounted on the first main surface;
A through via formed in the substrate so as to penetrate between the first main surface and the second main surface, and an opening diameter gradually increases from the first main surface toward the second main surface;
A substrate heat dissipation structure having a thermal conductivity, formed so as to correspond to the shape of the through via, and inserted into the through via and thermally connected to the heat-generating component.   The through via penetrates between the first main surface and the second main surface, and on the first main surface side, the opening diameter increases from the first main surface toward the second main surface. The board | substrate heat dissipation structure of Claim 1 formed in the said board | substrate so that it might become large gradually.   The substrate heat dissipation structure according to claim 1, wherein the heat generating component and the heat conducting core are connected by solder. A heat dissipating part having thermal conductivity, mounted on the second main surface and thermally connected to the heat conducting core;
The board | substrate heat dissipation structure of any one of Claims 1-3 in which the said thermal radiation part receives the heat of the said heat-emitting component via the said heat conductive core, and thermally radiates this heat.   The thermal conductive sheet or the thermal radiation grease which has thermal conductivity, was provided between the thermal radiation part and the second main surface, and thermally connected between the thermal conduction core and the thermal radiation part. Substrate heat dissipation structure. A through via is formed in the substrate so as to penetrate between the first and second main surfaces of the substrate and the opening diameter gradually increases from the first main surface toward the second main surface. A through via forming step;
A first solder application step of applying solder to the second main surface;
A thermally conductive core mounting step of inserting a thermally conductive core having thermal conductivity and corresponding to the shape of the through via into the through via; and
After the first solder applying step and the heat conducting core attaching step, the solder applied in the first solder applying step is heated and melted to fix the heat conducting core to the through via. A heat conducting core fixing step;
A second solder application step of applying solder to the first main surface after the heat conductive core fixing step;
After the second solder application step, heat is applied to the solder applied in the second solder application step to melt the solder so that the heat generating component is thermally connected to the heat conducting core. A method of assembling a substrate heat dissipation structure, comprising: a heat generating component mounting step mounted on a main surface of the circuit board.   In the through via forming step, the first main surface side passes through the first main surface and the second main surface, and the opening diameter is changed from the first main surface to the second main surface. The method of assembling a substrate heat dissipation structure according to claim 6, wherein through vias are formed in the substrate so as to gradually increase toward the substrate.   The heat-radiating component mounting step of mounting a heat-radiating component having thermal conductivity on the second main surface so as to be thermally connected to the heat-conducting core after the heat-generating component mounting step. Or a method for assembling the substrate heat dissipation structure according to 7.   9. The method of assembling a board heat dissipation structure according to claim 8, wherein in the heat dissipation component mounting step, a heat conductive sheet or heat dissipation grease having thermal conductivity is provided between the heat dissipation portion and the second main surface.

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