JP2014146843A - Heat dissipation structure of control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat dissipation structure of a control device, which can achieve increase in mounting area of an electronic component and downsizing of a printed circuit board while ensuring a radiation performance of the electronic component.SOLUTION: A heat dissipation structure of a control device comprises: a printed circuit board 2 having a peripheral part 2E sandwiched by a base 31 and a cover 32 to be included in a casing 3; a heat dissipation pattern 6 which extends from a mounting region 4P of an electronic component 4 of the printed circuit board 2 to the peripheral part 2E which becomes a mounting forbidden zone; and a heat transfer part 7 provided on the peripheral part 2E, for transferring heat from the heat dissipation pattern 6 to the base 31. The printed circuit board 2 includes a first conductor layer 23 formed in an inside layer of the printed circuit board 2 and a second conductor layer 25 which becomes a mounting surface, in which the heat dissipation pattern 6 is formed in the same layer with the first conductor layer 23.

Description

  The present invention relates to a heat dissipation structure for a control device.

  Conventionally, as a heat dissipation structure of a control device, a through hole is provided that penetrates a printed circuit board on which an electronic component is mounted, and heat of the electronic component is transmitted to the surface opposite to the mounting surface of the printed circuit board through the through hole. There is known one that transmits to the outer structure via a high thermal conductivity material filled between the opposite surface and the outer structure (for example, see Patent Document 1).

JP-A-9-55459

  However, in the heat dissipation structure of such a conventional control device, the through hole is provided in the mounting area of the electronic component, and the heat of the electronic component is transmitted to the surface opposite to the mounting surface of the printed board in the mounting area. Therefore, the surface of the printed circuit board opposite to the surface on which the electronic components are mounted is exclusively used as a heat dissipation path, and the mounting surface of the printed circuit board is not effectively used.

  Therefore, when many electronic components are mounted, it is necessary to use a printed circuit board that has at least an area corresponding to the mounting area of the electronic components, and the substrate size must be increased.

  Therefore, an object of the present invention is to obtain a heat dissipation structure for a control device that can increase the mounting area of an electronic component and reduce the size of a printed circuit board while ensuring heat dissipation of the electronic component.

  The present invention provides an electronic component mounted on a printed circuit board in a control device including a multilayer printed circuit board and an outer structure body including a first divided case and a second divided case containing the printed circuit board. Is a heat dissipation structure of a control device that transfers heat from the surface opposite to the mounting surface of the printed circuit board to the outer structure body and dissipates heat outward from the outer structure body, the electronic component of the printed circuit board A heat radiation pattern is extended from the mounting area to the peripheral edge that is the mounting prohibition band of the printed circuit board, and a heat transfer portion that transfers heat from the heat dissipation pattern to the outer structure is provided on the peripheral edge. The printed circuit board includes a first conductor layer formed in an inner layer of the printed circuit board and a second conductor layer serving as the mounting surface, and the heat dissipation pattern includes the first conductive layer. Characterized in that it is formed in the same layer as the layer.

  According to the present invention, the heat of the electronic component mounted on the mounting surface of the printed circuit board is provided in the heat radiation pattern that extends to the peripheral edge that becomes the mounting prohibited band of the printed circuit board, and the peripheral edge that becomes the mounting prohibited band of the printed circuit board. The heat transfer part is transferred to the outer structure containing the printed circuit board via the heat transfer part, so that the heat of the electronic component is transferred to the opposite surface of the printed circuit board at the peripheral part which is the mounting prohibited band of the printed circuit board. Can do. Therefore, the printed circuit board can mount other electronic components on the surface opposite to the mounting area of the electronic components, ensuring the heat dissipation of the electronic components, increasing the mounting area of the electronic components, and reducing the size of the printed circuit board. Can be achieved. In addition, by forming the heat dissipation pattern in the same layer as the first conductor layer, the heat of the electronic component mounted on the second conductor layer is dissipated by the heat dissipation pattern, and other areas of the same layer are used as circuit patterns. It can be used.

FIG. 1 is an external perspective view of an electronic control device to which a heat dissipation structure for a control device according to a first embodiment of the present invention is applied, viewed obliquely from below. FIG. 2 is an exploded perspective view of the electronic control device shown in FIG. 1 as viewed obliquely from below. FIG. 3 is a plan view of a printed circuit board on which electronic components are mounted in the heat dissipation structure of the control device according to the first embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view along the line AA in FIG. FIG. 5 is a cross-sectional view corresponding to FIG. 4 showing a modification of the first embodiment of the present invention. FIG. 6 is a cross-sectional view corresponding to FIG. 4 showing the heat dissipation structure of the control device according to the second embodiment of the present invention. FIG. 7 is a heat dissipation structure for a control device according to the third embodiment of the present invention, and is a cross-sectional view corresponding to FIG. FIG. 8 is a heat dissipation structure of the control device according to the fourth embodiment of the present invention, and is a cross-sectional view corresponding to FIG. FIG. 9 is a plan view of a printed circuit board corresponding to FIG. 3 in the heat dissipation structure of the control device according to the fifth embodiment of the present invention. FIG. 10 is a plan view of a printed circuit board corresponding to FIG. 3 in the heat dissipation structure of the control device according to the sixth embodiment of the present invention. FIG. 11 is a plan view of a printed circuit board corresponding to FIG. 3 in the heat dissipation structure of the control device according to the seventh embodiment of the present invention. FIG. 12 is a bottom view of an electronic control device to which the heat dissipation structure of the control device according to the eighth embodiment of the present invention is applied. FIG. 13 is an enlarged cross-sectional view along the line BB in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that similar components are included in the following embodiments. Therefore, in the following, common reference numerals are given to those similar components, and redundant description is omitted.

(First embodiment)
The heat dissipation structure of the control device according to the present embodiment is applied to, for example, the electronic control device 1 shown in FIG. As shown in FIG. 2, the electronic control device 1 includes a printed circuit board 2, a casing (outer casing) having a base (first divided case) 31 and a cover (second divided case) 32 that enclose the printed circuit board 2. Structure) 3. In the present embodiment, the printed circuit board 2 formed in a rectangular shape is used, but the shape is not particularly limited.

  The electronic control device 1 is used in, for example, an automobile engine control unit, a steering control unit, a brake control unit, or the like, and is attached to an automobile body. Of course, the electronic control device is not limited to an automobile.

  As shown in FIGS. 2 and 3, an electronic component 4 is mounted on the printed circuit board 2. Examples of the electronic component 4 include a capacitor, a coil, a transistor, and a semiconductor element in an engine control unit. Some of these electronic components 4 exhibit high exothermicity (for example, semiconductor elements, power transistors, and inverters) when operated, and FIG. 2 shows only the highly exothermic electronic component 4 for convenience. Other electronic components are not shown.

  The base 31 and the cover 32 are each formed of a material excellent in heat resistance and heat dissipation, for example, an aluminum plate, an aluminum die cast, iron or the like. The base 31 and the cover 32 are formed substantially along the outer shape of the printed circuit board 2 so that the printed circuit board 2 can be included. That is, in the present embodiment, the casing 3 is formed in a substantially rectangular parallelepiped shape as a whole by joining both the base 31 and the cover 32.

  As shown in FIG. 2, the base 31 has both sides 31 a and 31 b facing in the short width direction of a substantially rectangular plate material bent in two steps in the valley folding direction toward the inside of the casing 3. The front end surface 311 is parallel to the bottom surface 31 c and serves as a support surface for the printed circuit board 2 and a heat receiving surface from the printed circuit board 2.

  In addition, the four corners of the base 31 are provided with fixing surfaces 312 formed by embossing inward of the casing 3, and mounting holes 313 through which the mounting screws 5 are inserted are respectively provided on the fixing surfaces 312. Is formed. Further, a pair of mounting brackets 314 for mounting the electronic control device 1 to a vehicle body or the like project from substantially the center portion of both side portions 31d and 31e facing the long width direction of the base 31.

  The cover 32 is provided so that the side wall 321 surrounds the outer periphery of the printed circuit board 2 and the base 31 from the peripheral portion of the top surface 32a having a rectangular shape. On the inner surface of the side wall 321, a stepped portion 322 is formed continuously around the inner wall of the cover 32 so that the upper portion on the base end side is narrow and the lower portion on the distal end side is wide. A stepped surface 322a of 322 presses the peripheral edge of the printed circuit board 2.

  In addition, at the four corners of the stepped portion 322 circulated around, a pressing surface 323 having a stepped surface 322a widened corresponding to the formation position of the fixing surface 312 of the base 31, is provided on the pressing surface 323. A screw hole 324 for screwing the mounting screw 5 is formed. At this time, the fixing surface 312 of the base 31, the pressing surface 323 of the cover 32, and the mounting screw 5 serve as a fixing portion F that fixes the printed circuit board 2. Note that the top surface 32a of the cover 32 is not flat, but is unevenly formed substantially along the protruding shape of electronic components and other functional components mounted on the printed circuit board 2.

  Then, as shown in FIG. 4, the cover 32 is covered from above the printed circuit board 2 with the peripheral edge of the printed circuit board 2 placed on the front end surface 311 serving as the support surface of the base 31, whereby the side wall of the cover 31 is covered. 321 is fitted in close contact with the outer periphery of the base 31 with the printed circuit board 2 included. At this time, the peripheral edge portion of the printed circuit board 2 is sandwiched between the front end surface 311 of the base 31 and the step surface 322 a of the cover 31.

  As shown in FIGS. 2 and 3, insertion holes 21 through which the mounting screws 5 are inserted are formed at the four corners of the printed circuit board 2 corresponding to the positions where the mounting holes 313 of the base 31 are formed. Then, as shown in FIG. 2, the mounting screw 5 inserted through the mounting hole 313 from below the base 32 is inserted into the insertion hole 21 of the printed circuit board 2, and then screwed into the screw hole 324 of the cover 32 to be tightened. Thus, the printed circuit board 2 is sandwiched between the base 31 and the cover 32 and fixed in a state of being included in the casing 3.

  As shown in FIG. 4, the printed circuit board 2 has a multilayer structure, and an insulating resin material such as glass epoxy resin is used as the base portion 22, and a wiring circuit layer, an insulating layer, and the like are laminated on the front and back surfaces of the base portion 22. It is formed by doing. In the present embodiment, in the general region where the electronic component 4 of the printed circuit board 2 is mounted, the first conductor layer 23, the prepreg layer 24, and the second conductor layer are sequentially arranged from the front and back surfaces of the base portion 22 outward. 25 and a resist layer 26 are laminated.

  The above-described highly exothermic electronic component 4 is mounted on the second conductor layer 25 on one side (upper surface in FIG. 4) of the printed circuit board 2. At this time, the mounting region 4P of the electronic component 4 is a portion where the resist layer 26 is not provided in advance. The electronic component 4 is mounted by brazing the lead 41 of the electronic component 4 to the second conductor layer 25 with the solder 42.

  Since the peripheral edge 2E of the printed circuit board 2 is sandwiched between the tip surface 311 of the base 31 and the step surface 322a and the pressing surface 323 of the cover 32 as described above, the electronic component 4 is mounted. This is a mounting prohibited band (indicated by the hatched portion in FIG. 3).

  By the way, the heat generated in the electronic component 4 mounted on the printed circuit board 2 is once transmitted to the casing 3 and then released to the outside (in the atmosphere) from the casing 3.

  Here, in the present embodiment, as shown in FIGS. 3 and 4, the heat radiation pattern 6 is extended from the mounting region 4 </ b> P of the electronic component 4 of the printed board 2 to the peripheral edge 2 </ b> E serving as a mounting prohibited band of the printed board 2. In addition, a heat transfer portion 7 that transfers heat from the heat radiation pattern 6 to the casing 3 is provided on the peripheral edge portion 2E. The heat of the electronic component 4 is transmitted to the casing 3, that is, the distal end surface 311 of the base 31 in this embodiment via the heat radiation pattern 6 and the heat transfer portion 7. Thus, the tip surface 311 is a heat receiving portion of the base 31.

  At this time, the heat radiation pattern 6 is formed in the same layer as the first conductor layer 23 of the printed circuit board 2, so that the heat radiation pattern 6 is formed in the inner layer of the printed circuit board 2. Therefore, the heat radiation pattern 6 is provided in a layer on the inner side of the board from the second conductor layer 25 which becomes the mounting surface of the printed board 2, and the heat radiation pattern 6 and the printed board 2 are mounted. A prepreg layer 24 serving as a heat blocking region (heat blocking layer) is interposed between the second conductor layer 25 serving as a surface. The prepreg layer 24 is formed, for example, by impregnating a glass cloth of a reinforcing material with a thermosetting resin. Of course, the heat dissipation pattern 6 is formed of a material having high thermal conductivity, in this embodiment, copper foil. The heat dissipation pattern 6 is separated by the first conductor layer 23 and the prepreg layer 24 provided in the same layer. ing. In the present embodiment, the prepreg layer 24 is formed with a protruding portion 24a that protrudes toward the layer on which the heat dissipation pattern 6 and the first conductor layer 23 are formed. The conductor layer 23 is separated. If it carries out like this, it will be suppressed that the heat | fever of the electronic component 4 transmitted to the thermal radiation pattern 6 will be transmitted to the 1st conductor layer 23, and it can thermally radiate to the exterior more rapidly. In addition, the mounting region of the first conductor layer 23 can be suppressed from being affected by the heat of the electronic component 4.

  As described above, the heat dissipation pattern 6 is formed in the same layer as the first conductor layer 23, and is a formation layer of another circuit pattern formed on the printed circuit board 2, that is, the above-described second conductor layer 25. It is formed in a different layer.

  Here, in this embodiment, the heat transfer part 7 is formed by a plurality of through holes 71 for heat transfer that are in contact with the heat radiation pattern 6 and penetrate in the thickness direction of the printed circuit board 2. The through hole 71 is formed by applying plating (copper) to the inner surface of the through hole penetrating the printed circuit board 2, and heat is transmitted through the plated portion.

  In the printed circuit board 2, the second conductor layer 25 serves as a mounting surface of the electronic component 4, and a resist layer 26 is provided on the second conductor layer 25 to be insulated. For this reason, in the through-hole formation region 71P in which the plurality of through-holes 71 are formed in groups, a non-formation region 26P of the resist layer 26, that is, a portion where the resist layer 26 is not provided in advance is provided. The non-formation region 26P of the resist layer 26 is also provided in the mounting region 4P of the electronic component 4 described above.

  Further, the non-formation region 26P of the resist layer 26 is the same layer as the second conductor layer 25 provided on both surfaces, and is provided as a solid surface 27 of the conductor. However, the non-formation region 26 </ b> P is different from the solid surface 27 of the conductor in that it includes the peripheral portion of the printed circuit board 2. Then, the heat transmitted to the through hole 71 is transmitted from the end surface of the through hole 71 in contact with the front end surface 311 of the base 31 and the solid surface 27 to the front end surface 311.

  As shown in FIG. 3, the heat radiation pattern 6 is formed larger than the outer shape of the electronic component 4 in the mounting region 4 </ b> P of the electronic component 4. Note that the shape of the heat radiation pattern 6 in the mounting region 4 </ b> P of the electronic component 4 may be substantially the same as the outer shape of the electronic component 4.

  As shown in FIG. 3, in the printed circuit board 2, as described above, the insertion hole 21 through which the mounting screw 5 is inserted becomes the fixing portion F of the printed circuit board 2, and the heat radiation pattern 6 is at least of the electronic component 4. It extends from the mounting region 4P to the vicinity of the fixed portion F. The heat radiation pattern 6 may be directly extended to the fixed portion F. Thus, when the heat radiation pattern 6 is extended to the vicinity of the fixing portion F or the fixing portion F, the electronic component 4 is disposed in the vicinity of the fixing portion F in order to shorten the heat transfer path. Is preferred. Furthermore, in the heat radiation pattern 6, a continuously extending portion 61 is continuously circulated around the peripheral portion of the printed board 2 with a predetermined width w.

  According to the above-described embodiment, the heat of the electronic component 4 mounted on the mounting surface of the printed circuit board 2 causes the heat radiation pattern 6 extending to the peripheral edge 2E to be a mounting prohibited band of the printed circuit board 2 and the peripheral edge 2E. Is transmitted to the tip surface 311 of the base 31 containing the printed circuit board 2 (see FIG. 4). The heat transfer path of the heat radiation pattern 6 is indicated by an arrow a, The heat transfer path of the transfer unit 7 is indicated by an arrow b). And the heat | fever of the electronic component 4 transmitted to the base 31 is transmitted to the bottom face 31c of the base 31 from the front end surface 311 as shown by the arrow c, and is discharged | emitted outside.

  Therefore, in the present embodiment, when the heat of the electronic component 4 is released to the outside, the peripheral portion 2E that becomes a mounting prohibition band of the printed circuit board 2 is effectively used, and the peripheral portion 2E causes electrons to be formed on the opposite surface of the printed circuit board 2. The heat of the component 4 can be transferred. As a result, the printed circuit board 2 can be provided with a region where other electronic components can be mounted on the opposite surface of the mounting region 4P of the electronic component 4, and the heat dissipation of the electronic component 4 can be ensured. 4 can be enlarged and the printed circuit board 2 can be downsized.

  Moreover, since the heat radiation pattern 6 is formed in the inner layer of the printed circuit board 2, a wide mounting surface can be secured on the surface of the printed circuit board 2, and the printed circuit board 2 can be further downsized.

  Furthermore, since the first conductor layer 23 is formed in another region of the same layer as the layer on which the heat dissipation pattern 6 is formed while forming the heat dissipation pattern 6 on a part of the inner layer of the printed circuit board 2, Unused areas can be used effectively.

  Further, the prepreg layer 24 serving as a heat blocking region (heat blocking layer) is formed with a protruding portion 24a that protrudes toward the layer where the heat radiation pattern 6 and the first conductor layer 23 are formed. Since the heat dissipation pattern 6 and the first conductor layer 23 are separated, the heat of the electronic component 4 transmitted to the heat dissipation pattern 6 can be suppressed from being transmitted to the first conductor layer 23. As a result, heat can be radiated to the outside more quickly, and the mounting region of the first conductor layer 23 can be suppressed from being affected by the heat of the electronic component 4.

  Furthermore, since the heat transfer portion 7 is formed by the through hole 71, the heat transferred to the heat radiation pattern 6 can be efficiently transferred to the opposite surface of the printed circuit board 2 through the through hole 71.

  Furthermore, when the resist layer 26 is provided on the mounting surface of the printed circuit board 2, since the non-formation region 26P of the resist layer 71 is provided in the through-hole formation region 71P, as shown by an arrow d in FIG. Heat dissipation from 71 to the mounting surface side of the printed circuit board 2 can be efficiently performed without being disturbed by the resist layer 26. Then, the heat released to the mounting surface side of the printed circuit board 2 is released outward from the casing 3 via the cover 32.

  Moreover, since the heat radiation pattern 6 is formed in the mounting region 4P of the electronic component 4 so as to be substantially the same as or larger than the outer shape of the electronic component 4, the heat transfer efficiency from the electronic component 4 to the heat radiation pattern 6 is improved. be able to.

  If the heat radiation pattern 6 is provided at or around the part of the printed circuit board 2 where the electronic component 4 is mounted, the part of the printed circuit board 2 where the electronic component 4 is not mounted is used as another circuit pattern. Will be able to.

  Furthermore, since the heat radiation pattern 6 extends at least from the mounting region 4P of the electronic component 4 to the fixing portion F or the vicinity of the fixing portion F, the heat of the electronic component 4 transmitted through the heat radiation pattern 6 is transferred to the fixing portion F. Can be efficiently transmitted to the casing 3.

  Furthermore, since the heat radiation pattern 6 is provided on the inner layer side of the board from the mounting surface of the printed circuit board 2, and the prepreg layer 24 is provided between the heat radiation pattern 6 and the mounting surface of the printed circuit board 2. Since the heat of the heat radiation pattern 6 can be shielded by the prepreg layer 24 while the heat of the electronic component 4 is transferred to the heat transfer portion 7 via the heat radiation pattern 6, heat is radiated from the surface of the general mounting region of the printed circuit board 2. It is possible to suppress the thermal influence on other electronic components and functional components mounted on the printed circuit board 2.

  In addition, by disposing the electronic component 4 in the vicinity of the fixed portion F, the distance between the electronic component 4 that is a heat generation source and the heat receiving portion of the casing 3 can be further shortened. Release efficiency can be increased.

  Further, since a part of the heat radiation pattern 6 is formed around the peripheral edge 2E of the printed circuit board 2, the heat of the electronic component 4 is transmitted to the peripheral edge of the printed circuit board 2 through the heat radiation pattern 6, and the peripheral edge 2E. Since heat can be transferred to the periphery of the sandwiched portion between the base 31 and the cover 32, heat can be dissipated from a large area of the casing 3 and heat radiation efficiency can be increased.

  The heat radiation pattern 6 is provided at or around the portion of the printed circuit board 2 where the electronic component 4 is mounted, and a part of the heat radiation pattern 6 is extended along the peripheral edge 2E of the printed circuit board 2. For example, the heat radiation efficiency can be improved while effectively using the area of the printed circuit board 2 where the electronic component 4 is not mounted.

  Furthermore, since the heat radiation pattern 6 is formed on the first conductor layer 23 different from the second conductor layer 25 which is the formation layer of another circuit pattern formed on the printed circuit board 2, the heat radiation pattern 6 and other circuit It can be avoided that the patterns interfere with each other. Thereby, the freedom degree of the layout of the thermal radiation pattern 6 and another circuit pattern can be raised.

  In addition, by forming the heat radiation pattern 6 in the same layer as the first conductor layer 23 which is a formation layer of other circuit patterns formed on the printed board 2, the thickness of the printed board 2 is reduced and the weight is reduced. Can be planned. In this case, it is assumed that the second conductor layer 25 is omitted.

  Here, FIG. 5 shows a modification of the first embodiment. In this modified example, the portion of the heat transferred from the heat transfer portion 7 to the base 31 is such that both side portions 31 a and 31 b of the base 31 are once bent inward of the casing 3, and then the tip portion is the side wall of the cover 32. The front end surface 311a is bent as a support surface of the printed circuit board 2 and a heat receiving surface from the printed circuit board 2 so as to be parallel to the bottom surface 31c. A plurality of heat radiating fins 315 are integrally projected on the outer side of the tip surface 31 serving as a heat receiving surface.

  Even in the case where the tip end surface 311a of the base 31 is formed in a cross-sectional crank shape as in this modification, the printed circuit board 2 is supported and the electrons are transferred via the heat transfer section 7 as in the first embodiment. The heat of the component 4 can be received. Moreover, according to this modification, the heat radiation effect can be further improved by providing the heat radiation fins 315 on the outer side of the front end surface 311a.

(Second Embodiment)
The main difference between the present embodiment and the first embodiment is that the contact portion between the through hole 71 and the tip end surface 311 of the base 31 and the solid surface 27 of the peripheral portion 2E of the printed circuit board 2 provided with the through hole 71. This is because a heat radiating plate 72 as a heat conducting material is interposed at a contact portion between the base 31 and the tip surface 311 of the base 31.

  The heat radiating plate 72 is made of a material having excellent thermal conductivity, such as an aluminum plate, aluminum die-casting, iron, etc., and between the through hole 71 and the tip end surface 311 of the base 31 and the solid surface 27. The space between the front end surface 311 of the base 31 is closely filled.

  Also according to this embodiment described above, the same operations and effects as those of the first embodiment can be achieved.

  Moreover, according to this embodiment, there exists an advantage that the heat-transfer efficiency from the through hole 71 to the base 31 can further be improved through the heat sink 72 which is a heat conductive material. The heat radiating plate 72 may be provided at any one of a contact portion between the through hole 71 and the tip surface 311 of the base 31 and a contact portion between the solid surface 27 and the tip surface 311 of the base 31. .

  Of course, even in the present embodiment, the tip end surface 311a and the heat radiating fins 315 can be formed in the heat receiving portion and the heat radiating portion of the base 31 as in the modification shown in FIG.

(Third embodiment)
The main difference between the present embodiment and the second embodiment is that the heat dissipating grease 73 is used as the heat conducting material, and the heat dissipating grease 73 is filled in the through holes 71.

  In addition, when filling the heat radiation grease 3 into the through hole 71, the heat radiation grease 3 is filled into the through hole 71 from the heat radiation pattern 6 side toward the base 31.

  Also according to this embodiment described above, the same operations and effects as those of the second embodiment can be achieved.

  Further, according to the present embodiment, since the heat radiation grease 73 is filled in the through hole 71, the thermal conductivity of the through hole 71 is further improved as compared with heat radiation through the air, and the through hole 71 moves to the base 31. Further improvement in heat transfer efficiency can be achieved.

  Further, since the heat radiation grease 73 is filled into the through hole 71 from the heat radiation pattern 6 side toward the base 31, the space between the through hole 71 and the tip end surface 311 of the base 31 can be reliably filled with the heat radiation grease 73. The heat transfer efficiency from the through hole 71 to the base 31 can be further improved. Here, a heat conductive adhesive may be used instead of the heat dissipation grease.In this case, the manufacturing process is reduced as part of the assembly and fixing process of the control device, or the bonding strength is improved by bonding. You can also plan.

  Of course, even in the present embodiment, the tip end surface 311a and the heat radiating fins 315 can be formed in the heat receiving portion and the heat radiating portion of the base 31 as in the modification shown in FIG.

(Fourth embodiment)
The main difference between the present embodiment and the third embodiment is that the electronic components 4 are mounted on both surfaces of the printed circuit board 2 in association with the mounting regions 4P.

  In the present embodiment, when the electronic component 4 is mounted on both sides of the printed board 2 in correspondence with the mounting regions 4P, the first conductor layer 23, the prepreg layer 24, and the second conductor layer 25 of the printed board 2 are mounted. The resist layer 26 is formed so as to have a substantially symmetric structure with the base portion 22 as a boundary at least in the periphery where the electronic component 4 is mounted.

  Therefore, the heat radiation pattern 6 is provided on the inner layer side of the printed board 2 from the mounting surface on the front surface side and the mounting surface on the back surface side at least from the second layer.

  Furthermore, between the heat dissipation pattern 6 and the front and back mounting surfaces of the printed circuit board 2, a heat blocking region (heat blocking layer: prepreg layer 24) is provided.

  The heat of the electronic component 4 mounted on both sides is transmitted from the through hole 71 to the base 31 via the arrows a, b, and c on both sides of the printed circuit board 2. Further, heat is radiated also into the casing 3 through the through hole 71 as shown by an arrow d, and the heat is released outward from the cover 32.

  Also according to the present embodiment described above, the same operations and effects as those of the third embodiment can be achieved.

  Further, according to the present embodiment, since the electronic components 4 are mounted on both surfaces of the printed circuit board 2 so as to correspond to the mounting regions 4P, more electronic components 4 can be mounted on one printed circuit board 2. Thus, the mounting efficiency on the printed circuit board 2 having a certain area can be increased.

  Further, according to the present embodiment, the heat radiation pattern 6 is provided on the inner layer side of at least the second layer from the mounting surface on the front surface side and the rear surface mounting surface of the printed circuit board 2, and the heat radiation pattern 6 and the printed circuit board. Heat shielding regions (heat shielding layer: prepreg layer 24) are respectively provided between the two front and back mounting surfaces.

  Therefore, while the heat of the electronic component 4 is transferred to the heat transfer portion 7 through the heat radiation pattern 6, the heat of the heat radiation pattern 6 is shielded by the heat shielding area and radiated from the surface of the general mounting area of the printed circuit board 2. Can be suppressed. Therefore, while reducing the thermal influence on other electronic components and functional components mounted on the printed circuit board 2, the electronic component 4 is placed on the opposite surface of the printed circuit board 2 at the peripheral edge 2 </ b> E serving as a mounting prohibited band of the printed circuit board 2. The heat can be transmitted more reliably.

  Of course, even in the present embodiment, the tip end surface 311a and the heat radiating fins 315 can be formed in the heat receiving portion and the heat radiating portion of the base 31 as in the modification shown in FIG.

(Fifth embodiment)
In the present embodiment, as in the first embodiment, the electronic component 4 is disposed in the vicinity of the fixed portion F of the printed board 2A.

  Here, this embodiment is mainly different from the first embodiment in that the through-hole forming region 71P is formed in a band shape along one side of the printed board 2A closest to the mounting region 4P of the electronic component 4, and The heat radiation pattern 6 is extended along the through-hole forming region 71P.

  Also in this embodiment, a part 61 of the heat radiation pattern 6 is routed around the peripheral edge of the printed board 2A, and the heat radiation pattern 6 along the through-hole formation region 71P bypasses the insertion holes 21 at both ends. Then, it is connected to a part 61 of the heat radiation pattern 6. In the present embodiment, a plurality of highly heat-generating electronic components 4 (two in this embodiment) are mounted adjacent to each other, and the heat dissipation pattern 6 includes a mounting region 4P of the plurality of electronic components 4. It is formed as follows.

  Also according to this embodiment described above, the same operations and effects as those of the first embodiment can be achieved.

  In addition, according to the present embodiment, since the through-hole forming region 71P is formed in a strip shape along one side of the printed board 2A, the area of the through-hole forming region 71P is increased and the heat transferred from the heat radiation pattern 6 is increased. Can be transmitted to the base 31 efficiently. Thereby, even when a plurality of electronic components 4 are mounted adjacent to each other, the heat generated in the electronic components 4 can be efficiently released to the outside of the casing 3.

(Sixth embodiment)
In the present embodiment, similarly to the fifth embodiment, the highly heat-generating electronic component 4, the through-hole formation region 71 </ b> P, and the heat dissipation pattern 6 are provided along the side of the rectangular printed circuit board 2 </ b> B. It has been.

  Here, the main difference between the present embodiment and the fifth embodiment is that when the electronic component 4, the through-hole forming region 71P, and the heat radiation pattern 6 are one heat radiation set R, the heat radiation set R is It is provided along a plurality of sides of the printed circuit board 2B having a rectangular shape. In this embodiment, the heat dissipation set R is provided along three sides, but the heat dissipation set R may be provided along two sides or all four sides.

  In this case, in the through-hole formation region 71P, those corresponding to the respective sides are separated from each other, but the heat radiation pattern 6 is continuous in all the heat radiation sets R. Also in this embodiment, a part 61 of the heat radiation pattern 6 is routed around the peripheral edge of the printed circuit board 2A, and the heat radiation pattern 6 along the through-hole formation region 71P has a shape that bypasses the insertion hole 21. It has become.

  Also according to this embodiment described above, the same operations and effects as those of the fifth embodiment can be obtained.

  In addition, according to the present embodiment, when more electronic components 4 are to be mounted on one printed circuit board 2B, the larger number of electronic components 4 are divided into a plurality of groups along each side of the printed circuit board 2B. The heat generated in many of these electronic components 4 can be efficiently transmitted to the casing 3 and released outward.

(Seventh embodiment)
In the present embodiment, as in the sixth embodiment, a plurality of through-hole formation regions 71P are formed in independent strips on each side along the plurality of sides of the printed circuit board 2C having a rectangular shape. At the same time, the heat radiation pattern 6 extending along these independent through-hole formation regions 71P is continuous while bypassing the insertion hole 21.

  Here, this embodiment is mainly different from the sixth embodiment in that the electronic component 4 having high heat generation is mounted on the central portion of the printed board 2C. Then, the heat radiation pattern 6 provided in the central portion of the printed circuit board 2C so as to include the mounting region 4P of the electronic component 4 is disposed in the portions extending along the plurality of through-hole forming regions 71P. 4 are connected via a connection pattern 62 extending in a T-shape around the center. In the present embodiment, one electronic component 4 is mounted on the central portion of the printed circuit board 2C, but a plurality of electronic components 4 may be mounted together in the central portion.

  Also according to this embodiment described above, the same operations and effects as those of the sixth embodiment can be achieved.

  In addition, according to the present embodiment, the heat of the electronic component 4 mounted on the central portion of the printed circuit board 2 </ b> C is generated by the heat radiation pattern 6 including the connection pattern 62 along the plurality of sides of the printed circuit board 2 </ b> C. It is transmitted to the through hole formation region 71P. Thereby, the heat of the electronic component 4 at the center can be transmitted to the base 31 through the plurality of through-hole forming regions 71P, so that the heat dissipation efficiency can be further improved.

(Eighth embodiment)
In the present embodiment, as shown in FIG. 13, as in the first embodiment, the heat of the electronic component 4 is transmitted through the heat radiation pattern 6 and the heat transfer portion 7 </ b> A to the casing 3, specifically, the front end surface of the base 31. 311a is transmitted.

  Here, the present embodiment is mainly different from the first embodiment in that the heat transfer portion 7A is in contact with the heat radiation pattern 6 and penetrates in the thickness direction of the printed circuit board 2, and the base 31 and the cover 32 are separated. It is formed by the mounting screw 5 to be coupled.

  That is, the mounting screw 5 is inserted into the mounting hole 313 and the insertion hole 21 of the printed circuit board 2 from below the base 32 as shown in the first embodiment (see FIG. 2), and then the screw hole of the cover 32. 324 is tightened by screwing. At this time, the mounting screw 5 is brought into close contact with the inner periphery of the insertion hole 21 of the printed circuit board 2 so that the mounting screw 5 comes into contact with the heat radiation pattern 6.

  Also according to this embodiment described above, the same operations and effects as those of the first embodiment can be achieved.

  In addition, according to the present embodiment, the heat transfer portion 7A is formed by the mounting screw 5 that couples the base 31 and the cover 32, so that heat can be dissipated while the components (mounting screws 5) are shared. The heat of the electronic component 4 transmitted to the pattern 6 can be efficiently transmitted to the casing 3 (base 31), thereby providing an inexpensive product while simplifying the structure of the heat transfer unit.

  The preferred embodiments of the electronic control device according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various embodiments can be adopted without departing from the scope of the invention.

  For example, for each layer constituting the printed circuit board, the respective materials and the number of layers can be appropriately selected according to the application.

  In addition, the outer structure, through-hole, and other detailed specifications (shape, size, layout, etc.) can be changed as appropriate.

  Further, technical ideas other than the claims that can be grasped from the above embodiment will be described together with the effects thereof.

  (1) It is preferable that a resist layer is provided on the mounting surface of the printed board, and a non-resist layer formation region is provided in a through hole formation region.

  In this way, even when a resist layer is provided on the mounting surface of the printed circuit board, heat can be efficiently radiated from the through hole to the mounting surface side of the printed circuit board without being obstructed by the resist layer.

  (2) It is preferable that the heat transfer portion is a mounting screw that contacts the heat radiation pattern and penetrates in the thickness direction of the printed circuit board to couple the first divided case and the second divided case. It is.

  This makes it possible to efficiently transfer the heat of the electronic component transferred to the heat dissipation pattern to the outer structure (first divided case) while sharing the components (mounting screws). It is possible to provide an inexpensive product while simplifying the structure.

  (3) It is preferable that the heat radiation pattern be formed to be substantially the same as or larger than the outer shape of the electronic component in the mounting region of the electronic component.

  If it carries out like this, the heat-transfer efficiency from an electronic component to a thermal radiation pattern can be improved.

  (4) The printed circuit board has a fixed portion fixed between the first divided case and the second divided case, and the heat radiation pattern extends from at least the mounting region of the electronic component to the fixed portion or the vicinity of the fixed portion. It is preferable to extend.

  If it carries out like this, the heat | fever of the electronic component transmitted via a thermal radiation pattern can be efficiently transmitted to an outline structure from a fixing | fixed part.

  (5) The heat dissipating pattern is provided in a layer inside the substrate from at least the second layer from the mounting surface of the printed circuit board, and a heat blocking region is provided between the heat dissipating pattern and the mounting surface of the printed circuit board. Is preferred.

  In this way, the heat of the heat dissipation pattern can be shielded in the heat blocking area while the heat of the electronic component is transferred to the heat transfer part via the heat dissipation pattern, so that heat is dissipated from the surface of the general mounting area of the printed circuit board. The thermal influence on other electronic components and functional components mounted on the printed circuit board can be reduced.

  (6) The electronic component is preferably arranged in the vicinity of the fixed portion.

  In this way, the distance between the electronic component that is a heat generation source and the heat receiving portion of the outer structure can be further shortened, so that the heat release efficiency from the outer structure can be increased.

  (7) The heat radiation pattern is preferably formed so that a part of the heat radiation pattern is formed around the peripheral edge of the printed board.

  In this way, heat of the electronic component can be transmitted to the peripheral portion of the printed circuit board through the heat dissipation pattern, and heat can be transferred from the peripheral portion to the periphery of the sandwiched portion of the first divided case and the second divided case. Heat can be radiated from a large area of the structure, and the heat radiating efficiency can be increased.

  (8) It is preferable that the heat radiation pattern is formed in a layer different from the formation layer of other circuit patterns formed on the printed circuit board.

  In this way, it is possible to avoid the heat dissipation pattern and other circuit patterns from interfering with each other. Thereby, the freedom degree of the layout of a thermal radiation pattern and another circuit pattern can be raised.

  (9) The heat dissipation pattern is preferably formed in the same layer as the other circuit pattern forming layer formed on the printed circuit board.

  If it carries out like this, the thickness of a printed circuit board can be made thin and weight reduction can be achieved.

  (10) It is preferable that the printed circuit board has electronic components mounted on both sides of the printed circuit board.

  If it carries out like this, it will become possible to mount more electronic components with respect to one printed circuit board, and the mounting efficiency to the printed circuit board which has a fixed area can be improved.

2, 2A, 2B, 2C Printed circuit board 2E Peripheral edge of printed circuit board (mounting prohibited band)
24 Prepreg layer (Heat blocking area: Heat blocking layer)
24a Protruding part 3 Casing (outer structure)
31 base (first split case)
32 Cover (second split case)
4 Electronic Component 4P Mounting Area 6 Heat Dissipation Pattern 61 Part of Heat Dissipation Pattern 7, 7A Heat Transfer Part 71 Through Hole 72 Heat Dissipation Plate (Heat Conductive Material)
73 Heat Dissipation Grease (Heat Conductive Material)

Claims (10)

In a control device comprising a multilayered printed circuit board and an outer structure composed of a first divided case and a second divided case containing the printed circuit board, heat of electronic components mounted on the printed circuit board is obtained. A heat dissipation structure of the control device that transmits to the outer structure from the surface opposite to the mounting surface of the printed circuit board and dissipates heat outward from the outer structure,
A heat dissipation pattern extends from the mounting area of the electronic component on the printed circuit board to a peripheral edge that is a mounting prohibition band of the printed circuit board, and heat transfer is conducted to the peripheral edge from the heat dissipation pattern to the outer structure. Part is provided,
The printed circuit board includes a first conductor layer formed in an inner layer of the printed circuit board, and a second conductor layer serving as the mounting surface.
The heat dissipation structure for a control device, wherein the heat dissipation pattern is formed in the same layer as the first conductor layer. Between the layer where the heat dissipation pattern and the first conductor layer are formed and the second conductor layer, a heat blocking layer is provided,
The heat blocking layer has a protruding portion that protrudes toward the layer on which the heat dissipation pattern and the first conductor layer are formed,
The heat dissipation structure for a control device according to claim 1, wherein the heat dissipation pattern and the first conductor layer are separated by the protrusion.   The heat dissipation pattern is provided in a layer on the substrate inner side from at least the second layer from the mounting surface on the front surface side and the mounting surface on the back surface side of the printed circuit board. The heat dissipation structure of the described control device.   4. The heat dissipation structure for a control device according to claim 3, wherein the heat blocking layer is provided between the heat dissipation pattern and a mounting surface on the front and back sides of the printed circuit board.   5. The heat dissipation structure for a control device according to claim 1, wherein the heat dissipation pattern is provided in a portion where the electronic component of the printed circuit board is mounted or in the vicinity thereof.   6. The heat dissipation structure for a control device according to claim 1, wherein a part of the heat dissipation pattern is extended along a peripheral edge of the printed circuit board.   7. The heat transfer portion according to claim 1, wherein the heat transfer portion is a through hole for heat transfer that is in contact with the heat radiation pattern and penetrates in a thickness direction of the printed circuit board. Heat dissipation structure of control device.   A heat conductive material is interposed in at least one of a contact portion between the through hole and the outer structure body and a contact portion between a peripheral edge portion of the printed circuit board provided with the through hole and the outer structure body. The heat dissipation structure for a control device according to claim 7.   The heat dissipation structure for a control device according to claim 8, wherein the heat conductive material is filled in the through hole.   10. The heat dissipation structure for a control device according to claim 9, wherein the heat conductive material is filled in the through hole from at least the heat dissipation pattern side toward the outer structure.

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