ELECTRONIC MODULE AND METHOD OF MANUFACTURING THE SAME
The present invention relates to an electronic module and a method of manufacturing the same, and more specifically, an electronic module including a heat sink and a method of manufacturing the same. As one type of electronic module, regulators are known to obtain a desired output power from an input power. As shown in In the conventional regulator 100, as shown in Note that, in Patent Literature 1, as one type of electronic module, there is described a semiconductor device including cooling members provided on both surfaces of a semiconductor chip and each having fins to improve a thermal radiation property. Since the cooling members are provided on both surfaces of the semiconductor chip, the size of the electronic module becomes large. As described above, in electronic modules such as the conventional regulator, since the power part 110 and the controlling part 120 are provided and arranged upon a single plane, the size thereof as a whole becomes large. That is, there is a problem of difficulty in downsizing an electronic module that includes a heat sink such as a regulator. Thus, the present invention has an object to provide an electronic module that can be downsized, and a method of manufacturing the same. An electronic module according to one aspect of the present invention includes: a first electronic module including a first substrate that has a first principal surface and a second principal surface on a side opposite to the first principal surface, and a first electronic element that is mounted on the first principal surface; a second electronic module including a second substrate that has a third principal surface and a fourth principal surface on a side opposite to the third principal surface and that is arranged such that the third principal surface faces the first principal surface, a second electronic element that is mounted on the third principal surface and is electrically connected to the first electronic element with a first connecting member therebetween, and a third electronic element that is mounted on the fourth principal surface and is electrically connected to the first electronic element with a second connecting member therebetween passing through the second substrate in a thickness direction, the second electronic module being thermally connected to the first electronic module by the first and second connecting members; and a heat sink including a base plate that has a housing part therein, and housing the first and second electronic modules in the housing part such that the second principal surface of the first substrate is in contact with an inner wall surface of the housing part. The electronic module may further include a cap part that houses the second substrate and covers the first principal surface of the first substrate, an outer surface of the cap part being in contact with an inner wall surface of the housing part of the heat sink, wherein a side surface of the second substrate is in contact with an inner surface of the cap part. Further, in the electronic module, the cap part may be made of a metal having a surface subjected to insulating treatment. The electronic module may further include a sealing resin that fills an inside of the cap part so as to embed the first electronic element, the second electronic element, and the third electronic element. The electronic module may further include a cap part that covers the fourth principal surface of the second substrate, an outer surface of the cap part being in contact with an inner wall surface of the housing part of the heat sink. The electronic module may further include a sealing resin that fills an inside of the cap part so as to embed the third electronic element. The electronic module may further include a sealing resin that fills between the first electronic module and the second electronic module so as to embed the first electronic element and the second electronic element. Further, in the electronic module, the first substrate may include: a first insulating substrate; a conductive pattern that is provided on a principal surface on a first principal surface side of the first insulating substrate and is electrically connected to the first electronic element with a conductive binder therebetween; and a conductive layer that is provided on a principal surface on a second principal surface side of the first insulating substrate and is in contact with the inner wall surface of the housing part of the heat sink. Further, in the electronic module, a depressed portion is provided on the conductive layer, and a heat conductive member is arranged in the depressed portion so as to be in contact with the inner wall surface of the housing part. A method of manufacturing an electronic module according to one aspect of the present invention includes: mounting a first electronic element on one principal surface of a first substrate with a conductive binder therebetween; mounting a second electronic element on one principal surface of a second substrate with a conductive binder therebetween, and mounting a third electronic element on another principal surface of the second substrate with a conductive binder therebetween; assembling in which the second substrate is arranged facing the first substrate such that a first connecting member made of a conductive material is sandwiched between the first electronic element and the second electronic element and such that a second connecting member made of a conductive material is inserted into a through hole passing through the second substrate in a thickness direction and is connected to the first electronic element with a conductive binder therebetween, and thereafter, heat treatment is performed to fix the first to third electronic elements and the first and second connecting members, whereby a stack module is produced; and housing in which the stack module is housed in a housing part provided inside a base plate of a heat sink such that the other principal surface of the first substrate is in contact with an inner wall surface of the housing part. The method of manufacturing an electronic module may further include after the assembling and before the housing, putting a cap part having an outside shape fitting the housing part on the stack module so as to house the second substrate and cover the first principal surface of the first substrate, wherein in the housing, the stack module covered with the cap part is housed in the heat sink such that an outer surface of the cap part is in contact with an inner wall surface of the housing part. Further, in the method of manufacturing an electronic module, a resin injection hole passing through the cap part in a thickness direction is provided in the cap part, a through hole passing through the second substrate in a thickness direction is provided in the second substrate, and after the cap part is put on the stack module, a resin is injected through the resin injection hole of the cap part, thereby filling the inside of the cap part so as to embed the first electronic element, the second electronic element, and the third electronic element. The method of manufacturing an electronic module may further include after the assembling and before the housing, putting a cap part having an outside shape fitting the housing part on the stack module so as to cover the fourth principal surface of the second substrate, wherein in the housing, the stack module covered with the cap part is housed in the heat sink such that an outer surface of the cap part is in contact with the inner wall surface of the housing part. Further, in the method of manufacturing an electronic module, a resin injection hole passing through the cap part in a thickness direction is provided in the cap part, and the method further includes: after the cap part is put on the stack module, filling the inside of the cap part with a resin so as to embed the third electronic element by injecting the resin through the resin injection hole of the cap part; and after the housing, filling the inside of the housing part with a resin so as to embed the first electronic element and the second electronic element. In the electronic module according to the present invention, the first electronic module and the second electronic module that is thermally connected to the first electronic module by the first and second connecting members are housed in the housing part provided in the base plate of the heat sink, such that the second principal surface of the first substrate is in contact with the inner wall surface of the housing part. As a result, the first and second electronic modules are not provided upon the base plate, and the horizontal size of the base plate can be reduced to about the same size as a larger size between the horizontal sizes of the first and second electronic modules. Therefore, according to the present invention, the electronic module can be considerably downsized. Electronic modules according to embodiments of the present invention will be described below with reference to the drawings. Note that, in the drawings, the same numerical references are used for components each having an equivalent function, and descriptions of the components of the same numerical references will not be repeated. In addition, the drawings are schematic views, and a relation between thicknesses of respective components and plane dimensions, ratios among the thicknesses of the respective components, and the like differ from those of an actual electronic module. A first embodiment of the present invention will be described with reference to The electronic module 1 according to the first embodiment includes the electronic module 10, the electronic module 20 stacked on the electronic module 10, and the heat sink 30 housing therein the electronic module 10 and the electronic module 20. As shown in The electronic module 20 is electrically and thermally connected to the electronic module 10 by connecting members 18, 19, and 28 each made of a conductive material. The connecting members 18, 19, and 28 are provided, as shown in The connecting member 18 electrically connects an electronic element 12 and an electronic element 22. The connecting member 19 electrically connects the electronic element 12 and an electronic element 23. The connecting member 28 electrically connects a conductive pattern 14 and conductive patterns 25 and 26. From a viewpoint of noise reduction, the connecting members 18, 19, and 28 are preferably provided so as to connect the respective electronic elements taking the shortest routes. For example, the connecting members 18, 19, and 28 are each formed by a plate-like or columnar straight member. Note that the connecting members 18, 19, and 28 are each made of, for example, a copper (Cu), a molybdenum (Mo), an alloy of copper and molybdenum (Cu—Mo), or an alloy of copper and tungsten (Cu—W). Each component will be described below in detail. The electronic module 10 includes the substrate 11 having a principal surface 11 As shown in In addition, as seen in The electronic element 12 is, for example, an element that generates more heat than the electronic elements 22 and 23 of the electronic module 20. More particularly, the electronic element 12 is a switching element such as a power MOSFET and an Insulated Gate Bipolar Transistor (IGBT). A controlling terminal 12 The electronic module 20 includes, as shown in As shown in The substrate 21 includes an insulating substrate 24 made of an insulating material such as a ceramic, and the conductive patterns 25 and 26 formed by performing pattern processing to a conductive layer (such as a copper foil) provided on the insulating substrate 24. The conductive pattern 25 is provided on the principal surface of the insulating substrate 24 on the principal surface 21 In addition, as shown in The electronic element 22 is, as shown in The electronic element 23 is mounted on the principal surface 21 The heat sink 30 is for cooling the electronic module 10 and the electronic module 20, and as shown in The housing part 31 As shown in As described above, in the electronic module 1 of the present embodiment, the electronic module 10 and the electronic module 20 are stacked to form the stack module 29. In the stack module 29, the electronic module 10 and the electronic module 20 are thermally connected to each other by the connecting members 18, 19, and 28. Then, the stack module 29 is housed in the heat sink 30 such that the substrate 11 is in contact with the inner wall surface of the housing part 31 As a result, the electronic modules 10 and 20 are not provided upon the base plate 31, and the horizontal size of the base plate 31 can be reduced to about the same size as a larger size between the horizontal sizes of the electronic modules 10 and 20. Therefore, according to the present embodiment, the electronic module 1 can be considerably downsized. In addition, since heat emitted from the electronic elements 12, 22, and 23 mounted on the electronic modules 10 and 20 is transmitted to the heat sink 30 through the substrate 11 of the electronic module 10, a thermal radiation property can be ensured. Furthermore, by stacking the electronic module 10 and the electronic module 20 and connecting the electronic elements with the connecting members 18, 19, and 28, the interconnection distances between these two electronic modules can be shortened, which can reduce interconnection resistances and parasitic inductances. Therefore, according to the present embodiment, the electronic module 1 can be made to emit less noise. The electronic module 1 according to the present embodiment has, as shown in The cap part 40 is preferably made of a metal having a surface subjected to insulating treatment (for example, an aluminum subjected to alumite treatment), but may be made of an insulator such as a resin. In addition, the cap part 40 includes, as shown in By providing the cap part 40, heat from the electronic module 10 and the electronic module 20 can be transmitted to the heat sink 30 from not only the substrate 11 but also the cap part 40. For example, if the electronic element 12 is a switching element that emits a large amount of heat, the heat emitted from the electronic element 12 is radiated through the substrate 11 while being radiated through the connecting members 18 and 19, the electronic module 10, and the cap part 40. Therefore, according to the present embodiment, a thermal radiation property can be enhanced. As described above, since the electronic module 1 can radiate heat also through the cap part 40, a thermal resistance between the stack module 29 and the heat sink 30 is reduced, which can enhance the thermal radiation property. Therefore, according to the present embodiment, both downsizing electronic module and enhancing the thermal radiation property can be achieved. Furthermore, in the electronic module 1 including the cap part 40, the electronic module 10 and the electronic module 20 are housed in the heat sink 30 in a sealed state. This can reduce electromagnetic waves emitted to the outside accompanying the operation of the electronic module 1, and can reduce the influence of electromagnetic waves from the outside on the operation of the electronic module. Note that, as shown in In addition, the sealing resin 45 may be made of a resin containing a filler made of a material that has a high thermal conductivity thereby enhancing a heat conductive property. This can further enhance the thermal radiation property of the electronic module 1. Furthermore, as shown in Next, a method of manufacturing the electronic module 1 according to the first embodiment will be described. First, the electronic element 12 is mounted on the principal surface 11 Next, as shown in Next, the cap part 40 is put on the stack module 29 so as to house the substrate 21 and cover the principal surface 11 Next, a resin is injected through the resin injection hole 41 of the cap part 40, thereby filling the inside of the cap part 40 so as to embed the electronic element 12, the electronic element 22, and the electronic element 23 (resin filling step). More specifically, the resin injected to the resin injection hole 41 passes through the through hole 27 and fills a space (upper space) defined by the cap part 40 and the substrate 21, as well as fills a space (lower space) defined by the cap part 40, the substrate 11, and the substrate 21. Thereafter, in the end, the resin fills the upper space and the lower space to embed the electronic element 12, the electronic element 22, and the electronic element 23. In such a manner, by providing the through hole 27 in the substrate 21, the resin filling step does not need to be divided for the upper space and the lower space, which brings efficiency to the resin filling step. Next, the produced stack module 29 is housed in the housing part 31 Through the above steps, the electronic module 1 ( A second embodiment of the present invention will be described with reference to As shown in Note that the cap part 40A is preferably made of a metal having a surface subjected to insulating treatment (for example, an aluminum subjected to alumite treatment), but may be made of an insulator. As shown in By providing such a cap part 40A, heat from the electronic module 10 and the electronic module 20 can be transmitted to the heat sink 30 from not only the substrate 11 but also the cap part 40A. As a result, as in the case with the first embodiment, according to the second embodiment, both downsizing electronic module and enhancing the thermal radiation property can be achieved. Note that, as shown in In addition, as shown in The sealing resins 45A and 45B each may be made of a resin containing a filler made of a material that has a high thermal conductivity thereby enhancing a heat conductive property. This can further enhance the thermal radiation property of the electronic module 1A. Next, a method of manufacturing the electronic module 1A according to the second embodiment will be described. Since the steps up to producing the stack module 29 are the same to those of the method of manufacturing of the electronic module 1 according to the first embodiment, descriptions of the steps will be omitted, and the subsequent steps will be described. As shown in Next, a resin is injected through the resin injection hole 42 of the cap part 40A, thereby filling the inside of the cap part 40A so as to embed the electronic element 23. Next, the produced stack module 29 is housed in the housing part 31 Next, the inside of the housing part 31 Through the above steps, the electronic module 1A ( Although those skilled in the art may conceive an additional effect and various modifications of the present invention based on the foregoing descriptions, the aspects of the present invention are not limited to the abovementioned individual embodiments. Components over different embodiments may be combined as appropriate. Various additions, modifications, and partial deletions can be made in a range not deviating from the conceptual thought and gist of the present invention derived from in the claims and equivalents thereto. An electronic module 1 includes an electronic module 10 that includes a substrate 11 and an electronic element 12, an electronic module 20 that includes a substrate 21 arranged such that the principal surface 21a faces the principal surface 11a, an electronic element 22 electrically connected to the electronic element 12 with a connecting member 18 therebetween, and an electronic element 23 electrically connected to the electronic element 12 with a connecting member 19 therebetween passing through the substrate 21 in a thickness direction, the electronic module 20 thermally connected to the electronic module 10 by the connecting members 18 and 19, and a heat sink 30 that includes a housing part 31a therein and houses the electronic modules 10 and 20 in the housing part 31a such that the principal surface 11b is in contact with an inner wall surface of the housing part 31a. 1. An electronic module comprising:
a first electronic module including a first substrate that has a first principal surface and a second principal surface on a side opposite to the first principal surface, and a first electronic element that is mounted on the first principal surface; a second electronic module including a second substrate that has a third principal surface and a fourth principal surface on a side opposite to the third principal surface and that is arranged such that the third principal surface faces the first principal surface, a second electronic element that is mounted on the third principal surface and is electrically connected to the first electronic element with a first connecting member therebetween, and a third electronic element that is mounted on the fourth principal surface and is electrically connected to the first electronic element with a second connecting member therebetween passing through the second substrate in a thickness direction, the second electronic module being thermally connected to the first electronic module by the first and second connecting members; and a heat sink including a base plate that has a housing part therein, and housing the first and second electronic modules in the housing part such that the second principal surface of the first substrate is in contact with an inner wall surface of the housing part. 2. The electronic module according to 3. The electronic module according to 4. The electronic module according to 5. The electronic module according to 6. The electronic module according to 7. The electronic module according to 8. The electronic module according to 9. The electronic module according to the first substrate includes: a first insulating substrate; a conductive pattern that is provided on a principal surface on a first principal surface side of the first insulating substrate and is electrically connected to the first electronic element with a conductive binder therebetween; and a conductive layer that is provided on a principal surface on a second principal surface side of the first insulating substrate and is in contact with the inner wall surface of the housing part of the heat sink. 10. The electronic module according to 11. A method of manufacturing an electronic module comprising:
mounting a first electronic element on one principal surface of a first substrate with a conductive binder therebetween; mounting a second electronic element on one principal surface of a second substrate with a conductive binder therebetween, and mounting a third electronic element on another principal surface of the second substrate with a conductive binder therebetween; assembling in which the second substrate is arranged facing the first substrate such that a first connecting member made of a conductive material is sandwiched between the first electronic element and the second electronic element and such that a second connecting member made of a conductive material is inserted into a through hole passing through the second substrate in a thickness direction and is connected to the first electronic element with a conductive binder therebetween, and thereafter, heat treatment is performed to fix the first to third electronic elements and the first and second connecting members, whereby a stack module is produced; and housing in which the stack module is housed in a housing part provided inside a base plate of a heat sink such that the other principal surface of the first substrate is in contact with an inner wall surface of the housing part. 12. The method of manufacturing an electronic module according to after the assembling and before the housing, putting a cap part having an outside shape fitting the housing part on the stack module so as to house the second substrate and cover the first principal surface of the first substrate, wherein in the housing, the stack module covered with the cap part is housed in the heat sink such that an outer surface of the cap part is in contact with an inner wall surface of the housing part. 13. The method of manufacturing an electronic module according to a resin injection hole passing through the cap part in a thickness direction is provided in the cap part, a through hole passing through the second substrate in a thickness direction is provided in the second substrate, and after the cap part is put on the stack module, a resin is injected through the resin injection hole of the cap part, thereby filling the inside of the cap part so as to embed the first electronic element, the second electronic element, and the third electronic element. 14. The method of manufacturing an electronic module according to after the assembling and before the housing, putting a cap part having an outside shape fitting the housing part on the stack module so as to cover the fourth principal surface of the second substrate, wherein in the housing, the stack module covered with the cap part is housed in the heat sink such that an outer surface of the cap part is in contact with the inner wall surface of the housing part. 15. The method of manufacturing an electronic module according to a resin injection hole passing through the cap part in a thickness direction is provided in the cap part, the method further comprising: after the cap part is put on the stack module, filling the inside of the cap part with a resin so as to embed the third electronic element by injecting the resin through the resin injection hole of the cap part; and after the housing, filling the inside of the housing part with a resin so as to embed the first electronic element and the second electronic element.TECHNICAL FIELD
BACKGROUND ART
CITATION LIST
Patent Literature
SUMMARY OF INVENTION
Technical Problem
Solution to Problem
Advantageous Effects of Invention
BRIEF DESCRIPTION OF DRAWINGS
DESCRIPTION OF EMBODIMENTS
First Embodiment
Second Embodiment
REFERENCE SIGNS LIST





