control device

Abstract

This achieves miniaturization and weight reduction of the device while suppressing deterioration of cooling efficiency. [Solution] The control device comprises a first printed circuit board, a second printed circuit board, and an aluminum alloy housing. The housing has a pair of first mounting sections arranged side by side in the width direction, and a pair of second mounting sections spaced apart in one direction intersecting the width direction of the pair of first mounting sections and arranged side by side in the width direction. The first printed circuit board is mounted directly on the pair of first mounting sections and has a pair of first ends, each fixed to the first mounting sections using fastening components. The second printed circuit board is mounted directly on a pair of second mounting sections and has a pair of second ends, each fixed to the first ends using fastening components. The pair of second ends are positioned so as to cover at least a portion of each of the pair of first ends when viewed from the second printed circuit board to the first printed circuit board.

Description

Technical Field

[0001] This disclosure relates to a heat dissipation structure of an electronic device.

Background Art

[0002] As a conventional technology of the heat dissipation structure of an electronic device, for example, as in Patent Document 1, there is a structure in which circuit boards are arranged three-dimensionally to suppress an increase in the size of the electronic device, and the heat of the circuit boards can be efficiently dissipated through a fixing portion and a heat sink. FIG. 13 is a cross-sectional view showing an electronic device according to a conventional example. The electronic device 10 includes three circuit boards 30 (301, 302, 303) and two heat sinks 60 (601, 602). The circuit boards 30 and the heat sinks 60 are arranged in the Z direction in the order of the circuit board 301, the heat sink 601, the circuit board 302, the heat sink 602, and the circuit board 303. Thus, the heat sinks 60 are arranged adjacent to the circuit boards 30. In this embodiment, the circuit boards 30 and the heat sinks 60 are alternately arranged.

[0003] The case 21 has, for example, a support portion 211 with a multi-stage structure. The heat sink 601 is arranged in one of the support portions 211 (the first stage), and the heat sink 602 is arranged in another of the support portions 211 (the second stage).

[0004] The electronic device 10 includes a plurality of fixing portions 70 (701, 702, 703, 704). The plurality of fixing portions 70 are arranged in multiple stages so as to connect adjacent circuit boards 30 and heat sinks 60. The fixing portion 701 connects the circuit board 301 and the heat sink 601. The fixing portion 702 connects the heat sink 601 and the circuit board 302. The fixing portion 703 connects the circuit board 302 and the heat sink 602. The fixing portion 704 connects the heat sink 602 and the circuit board 303. The electronic device 10 includes a plurality of each of the fixing portions 701 to 704.

[0005] The second and third fixing portions 702 and 703 are positioned so as to overlap each other in a plan view. Overlapping each other means that at least a portion of them overlap, and preferably they overlap almost entirely. The first and fourth fixing portions 701 and 704 are positioned so as not to overlap with the fixing portions 702 and 703 in a plan view (see Patent Document 1, paragraphs

[0049] to

[0052] ). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-8628 [Overview of the project] [Problems that the invention aims to solve]

[0007] The heat dissipation structure described in Patent Document 1 is designed to release heat from the circuit board to the metal part of the housing via a fixed part and a heat sink. In other words, the heat dissipation method described in Patent Document 1 not only requires a heat sink, but also increases the overall size of the device by the amount of space required to house the heat sink within the housing.

[0008] This disclosure aims to provide electronic equipment that can achieve miniaturization and weight reduction while suppressing deterioration of cooling efficiency. [Means for solving the problem]

[0009] To solve the above problems, the control device according to this embodiment includes a first printed circuit board, a second printed circuit board, and an aluminum alloy housing that houses the first and second printed circuit boards. The housing has a pair of first mounting sections arranged side by side in the width direction, and a pair of second mounting sections arranged side by side in the width direction, spaced apart in one direction intersecting the width direction of the pair of first mounting sections. The first printed circuit board is mounted directly on the pair of first mounting sections and has a pair of first ends, each fixed to the first mounting sections using fastening components. The second printed circuit board is mounted directly on a pair of second mounting sections and has a pair of second ends, each fixed to the first mounting sections using fastening components. The pair of second ends are positioned so as to cover at least a portion of each of the pair of first ends when viewed from the second printed circuit board to the first printed circuit board. [Effects of the Invention]

[0010] According to the connector of this embodiment, it is possible to achieve miniaturization and weight reduction of the device while suppressing deterioration of cooling efficiency. [Brief explanation of the drawing]

[0011] [Figure 1A] Figure 1A is a perspective view showing an example of a control device according to this embodiment. [Figure 1B] Figure 1B is a front view of the control device shown in Figure 1A. [Figure 1C] Figure 1C is a top view of the control device shown in Figure 1A. [Figure 1D] Figure 1D is a right side view of the control device shown in Figure 1A. [Figure 2] Figure 2 shows the case where the cover of the enclosure is hidden, as in Figure 1A. [Figure 3] Figure 3 is an exploded perspective view of the control device shown in Figure 1A. [Figure 4] Figure 4 shows the result of hiding the base and cover in Figure 1D. [Figure 5] Figure 5 shows the assembly procedure for the control device. [Figure 6A] FIG. 6A is a perspective view of the base of the housing. [Figure 6B] FIG. 6B is a top view of the base shown in FIG. 6A. [Figure 7] FIG. 7 is a perspective view of the first printed circuit board. [Figure 8] FIG. 8 is a top view of the state where the first printed circuit board is mounted on the base. [Figure 9] FIG. 9 is a perspective view of the second printed circuit board. [Figure 10] FIG. 10 is a top view of the state where the first printed circuit board and the second printed circuit board are mounted on the base. [Figure 11] FIG. 11 is a perspective view of the third printed circuit board. [Figure 12] FIG. 12 is a top view of FIG. 2. [Figure 13] FIG. 13 is a cross-sectional view showing an electronic device according to the conventional example.

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] <<EMBODIMENT>> Hereinafter, a control device according to an embodiment of the present disclosure will be described with reference to the drawings. Note that components having the same function are denoted by the same reference numerals, and redundant description is omitted. FIG. 1A is a perspective view showing an example of the control device according to the present embodiment. FIG. 1B is a front view of the control device shown in FIG. 1A. FIG. 1C is a top view of the control device shown in FIG. 1A. FIG. 1D is a right side view of the control device shown in FIG. 1A. FIG. 2 is a view when the cover of the housing is not shown in FIG. 1A. FIG. 3 is an exploded perspective view of the control device shown in FIG. 1A. FIG. 4 is a view when the base and the cover are not shown in FIG. 1D. FIG. 5 is a view showing the procedure of assembling the control device.

[0013] The control device 1 of this embodiment is attached as a part of the device to be controlled, which is an external device, inside or outside the device to be controlled, and controls the state of the device to be controlled, such as speed, acceleration, position, orientation, etc. Here, the external device is defined as a concept including ships, aircraft, automobiles, moving bodies, etc. However, the control device 1 of the present disclosure is not limited to the type of function to be controlled, and may be configured to control other states and functions in addition to controlling the specific states described above. As shown in FIG. 3, the control device 1 mainly includes a base 11, a first printed circuit board 30A, a second printed circuit board 40A, a third printed circuit board 50A, a flexible substrate 33, a socket 34, and a cover 18.

[0014] The base 11 and the cover 18 constitute the housing 10A (FIG. 1) of the control device 1. The housing 10A houses the first printed circuit board 30A, the second printed circuit board 40A, the third printed circuit board 50A, the flexible substrate 33, and a part of the socket 34. In this example, both the base 11 and the cover 18 are made of an aluminum alloy. In the present disclosure, for convenience, only the base 11 or only the cover 18 may be referred to as the housing 10A.

[0015] <Base 11> FIG. 6A is a perspective view of the base of the housing. FIG. 6B is a top view of the base shown in FIG. 6A. The base 11 has a substantially box-shaped configuration with an open top (+z direction). The base 11 includes a bottom wall 111, side walls 112, 113, a front wall 114, and a rear wall 115. The side walls 112, 113, the front wall 114, and the rear wall 115 are configured to surround the edge of the bottom wall 111 in a posture standing perpendicular (z-axis direction) to the bottom wall 111.

[0016] (Bottom wall 111) The bottom wall 111 has a substantially rectangular flat plate shape. The bottom wall 111 has an upper surface 111a and a lower surface 111b (see Figure 5). In this disclosure, as shown in Figure 6B, the region on the upper surface 111a side at both ends along the longitudinal direction (y-axis direction) of the bottom wall 111, where the first ends 31a, 31b of the first printed circuit board 30A (see Figure 7) are mounted, is referred to as the "first mounting portion 110". That is, the bottom wall 111 has a pair of first mounting portions 110 arranged side by side in the width direction (x-axis direction). One of the pair of first mounting portions 110 is provided near the inner surface of one side wall, side wall 112, and the other is provided near the inner surface of the other side wall, side wall 113. On the outside of the first mounting portion 110, a pair of first stage portions 142, 143 (Figures 5, 6A) are provided along the first mounting portion 110. The first stepped sections 142 and 143 have a shape that protrudes upward (in the +z direction) from the upper surface 111a, forming a step with respect to the bottom wall 111.

[0017] A pair of second stages 152 and 153 (Figures 5 and 6A) are provided on the outside of the first stages 142 and 143, aligned with the first stages 142 and 143. The second stages 152 and 153 have a shape that protrudes upward (in the +z direction) from the first stages 142 and 143, forming a step with respect to the first stages 142 and 143. As a result, the first stages 142 and 143 and the second stages 152 and 153 form a stepped step with respect to the bottom wall 111. The second ends 41a and 41b (see Figure 9) of the second printed circuit board 40A are mounted on the upper (+z direction) surfaces of the second stages 152 and 153. In this disclosure, as shown in Figure 6B, the area on which the second ends 41a and 41b of the second stages 152 and 153 are mounted is referred to as the "second mounting section 120". The pair of second mounting sections 120 are provided such that one is located near the inner surface of one side wall, side wall 112, and the other is located near the inner surface of the other side wall, side wall 113. The second mounting sections 120 are provided at a distance above (+z direction) from the first mounting section 110 and are arranged side by side in the width direction (x direction) of the base 11. In other words, the pair of second mounting sections 120 are provided at a distance in one direction (+z direction) that intersects the width direction (x direction) of the pair of first mounting sections 110, and are arranged side by side in the width direction (x direction).

[0018] As shown in Figure 1B, the length of the bottom wall 111 in the width direction (x-axis direction) is narrower than the length of the top wall, the cover 18, in the width direction (x-axis direction). The base 11 has first steps 142, 143 and second steps 152, 153 along the longitudinal direction (y-axis direction) of the bottom wall 111. As shown in Figure 5, the first steps 142, 143 and second steps 152, 153 connect the wider portion of the base 11, which includes the side walls 112, 113, to the narrower portion of the base 11, which includes the bottom wall 111, so that the overall width of the base 11 changes gradually. In other words, the width of the base 11 is configured such that, from the viewpoint in Figure 1B, it narrows from a width equivalent to that of the cover 18 to the width of the bottom wall 111 by providing the first steps 142, 143 and second steps 152, 153.

[0019] As shown in Figure 6A, the bottom wall 111 is provided with multiple recesses 111x to reduce the weight of the base 11 while ensuring its rigidity. By providing multiple recesses 111x in the base 11, the base 11 is made lighter, and the convex-shaped parts act as ribs, ensuring the rigidity of the base 11. As shown in Figure 6B, the bottom wall 111 is provided with holes 110a to 110r, which are holes for fastening components such as bolts or studs. The second stages 152 and 153 are provided with holes 120a to 120j, which are holes for fastening components. Screw grooves are provided inside holes 110a to 110r and holes 120a to 120j.

[0020] (Side wall 112,113) Each of the pair of side walls 112 and 113 has a horizontally elongated, roughly rectangular flat plate shape. The side walls 112 and 113 are configured to stand upright relative to the bottom wall 111, facing each other in the width direction of the base 11. The side walls 112 and 113 are provided with a pair of protrusions 162 and 163 near the center of their inner sides, projecting toward the opposing side wall. The upper side (+z direction side) of the protrusions 162 and 163 protrudes longer toward the opposing side wall than the lower side (-z direction side). As a result, the protrusions 162 and 163 have an L-shaped cross-section, as shown in Figure 5. The third ends 51a and 51b (see Figure 11) of the third printed circuit board 50A are mounted on the upper side (+z direction side) of the protrusions 162 and 163. In this disclosure, as shown in Figure 6B, the region on which the third ends 51a and 51b of the protrusions 162 and 163 are mounted is referred to as the "third mounting portion 130". The pair of third mounting portions 130 are provided such that one is located near the inner surface of one side wall, side wall 112, and the other is located near the inner surface of the other side wall, side wall 113. Each of the third mounting portions 130 is located above (+z direction) from the second mounting portion 120 and is arranged in the width direction (x-axis direction) of the base 11. The third mounting portions 130 are provided with holes 130a to 130d, which are holes for fastening components. Screw grooves are provided inside the holes 130a to 130d.

[0021] (Front wall 114, back wall 115) The front wall 114 and rear wall 115 are based on the shape of a horizontally elongated, roughly rectangular flat plate, with the lower side (-z direction) being shorter than the upper side (+z direction) of the base 11 in the width direction (x-axis direction). In other words, they have a hexagonal shape with the lower corners of a horizontally elongated rectangle cut off. To put it another way, the front wall 114 and rear wall 115 have a hexagonal shape formed by the joining and connection of a horizontally elongated, roughly rectangular portion corresponding to the upper part and a trapezoidal shape corresponding to the lower part. The front wall 114 and rear wall 115 are configured to face each other in the length direction (y-axis direction) of the base 11, and are positioned upright relative to the bottom wall 111. The front wall 114 is provided with a hole 114a, located slightly closer to the side wall 112 than the center, into which the cylindrical portion of the socket 34 is inserted.

[0022] (Mounting part 13) On the outside of the side walls 112 and 113, there are mounting parts 13 made of aluminum alloy for attaching the control device 1 to the device to be controlled. As shown in Figure 1B, the mounting part 13 is positioned vertically (in the z-axis direction) relative to the base 11, between the upper surface (+z-direction side) of the cover 18 corresponding to the upper end of the housing 10A and the lower surface 111b of the bottom wall 111 corresponding to the lower end of the housing 10A, and is connected to the base 11. In this example, at least a part of the mounting part 13 is located on the outside of the housing 10A, between the second printed circuit board 40A and the third printed circuit board 50A, as shown in Figure 5. However, the control device 1 of this disclosure is not limited to these configurations, and may be configured to be located between the second printed circuit board 40A and the first printed circuit board 30A, as long as it is located between the upper surface (+z-direction side) of the cover 18 and the lower surface 111b of the bottom wall 111 corresponding to the lower end of the housing 10A. In this example, there are a total of six mounting parts 13, three on each of the side walls 112 and 113. Two mounting parts 13 are located near the front wall 114, two near the rear wall 115, and two near the center between the front wall 114 and the rear wall 115. Each mounting part 13 has a hole 13a (Figure 1C), which is a through hole for inserting a bolt, which is a fastening component.

[0023] <Cover 18> As shown in Figures 1A-1D and 3, the cover 18 is a component that covers the upper edge (+z direction side) of the base 11 from above, effectively covering the base 11. The cover 18 has a roughly rectangular flat plate shape, and the upper surface of the cover 18 corresponds to the upper end of the control device 1. The base 11 and the cover 18 are fastened together using fastening components such as bolts. However, in the figures of this disclosure, the fastening structure between the base 11 and the cover 18, such as bolts or holes through which bolts are inserted, is omitted from the illustration.

[0024] <First Printed Circuit Board 30A> Figure 7 is a perspective view of the first printed circuit board. Figure 8 is a top view of the first printed circuit board mounted on the base. Figure 7 shows the first printed circuit board 30A with a flexible substrate 33 and a socket 34 that allows for the insertion and removal of wiring terminals, for example. In Figure 8, each mounting part 13 is labeled with the symbols 13-1 to 13-6 to distinguish them from each other. The notation method for the mounting parts 13 is the same as in Figures 10 and 12, which will be described later. The first printed circuit board 30A has a first printed wiring board 31, a first electronic component 301 mounted on the first printed wiring board 31, and second electronic components 302 to 310. The first printed wiring board 31 is a wiring board made of an insulating material such as glass epoxy resin. In this example, the first printed wiring board 31 has a roughly rectangular flat shape. The first printed circuit board 31 has ends 31a and 31b along the longitudinal direction (y-axis direction) and ends 31c and 31d along the short direction (x-axis direction). In this disclosure, ends 31a and 31b are also referred to as "first ends 31a and 31b". The first ends 31a and 31b are mounted on the first mounting section 110.

[0025] The first printed circuit board 30A has holes 311a to 311r provided in the first printed wiring board 31 for fixing the first printed circuit board 30A to the bottom wall 111. The holes 311a to 311r are through holes for inserting fastening components such as bolts and studs. In Figure 8, fastening components are shown, so the holes 311a to 311r cannot be directly seen. On the other hand, in Figure 7, electronic components are shown, so some of the holes are visible, but not all of them are visible. Therefore, to make it possible to confirm the location where the holes 311a to 311r are provided, hole symbols have been added to the positions of the fastening components in Figure 8. This notation method is also used in Figures 10 and 12, which will be described later.

[0026] In this example, the first printed circuit board 30A is fixed to the bottom wall 111 by inserting bolts, a type of fastening component, into holes 311a to 311f and holes 311k to 311r, and inserting studs, another type of fastening component, into holes 311g to 311j. The holes 311a to 311f and holes 311m to 311r are located opposite the holes 110a to 110f and holes 110m to 110r provided in the first mounting section 110 when the first printed circuit board 30A is mounted on the base 11. In this disclosure, the fastening components inserted into the first mounting section 110 (all bolts in this example) are referred to as "first fastening components 81". The first ends 31a and 31b of the first printed circuit board 31 are directly mounted on a pair of first mounting sections 110, and each is fixed to the first mounting section 110 using a first fastening component 81. Here, "direct mounting" literally refers to the case where the first mounting section 110 and the first ends 31a and 31b are directly joined, but the control device 1 of this disclosure also includes thermal joining by applying, for example, thermal conductive grease between the first ends 31a and 31b and the first mounting section 110. This also applies to the joining of the second printed circuit board 41 and the second mounting section 120, and the joining of the third printed circuit board 51 and the third mounting section 130, which will be described later.

[0027] Studs are inserted into holes 311g to 311j. One end of the stud is inserted into holes 311g to 311j and into holes 110g to 110j which have screw grooves formed in the bottom wall 111, thereby fixing the first printed circuit board 30A to the bottom wall 111. The other end (upper end) of the stud inserted into holes 110g to 110j is a female thread and is used to fix the first printed circuit board 31 and the second printed circuit board 41.

[0028] The first electronic component 301 is the component that emits the largest amount of heat among the electronic components mounted on the first printed circuit board 31. That is, the second electronic components 302 to 310 are electronic components that generate less heat than the first electronic component 301. In this example, the first electronic component 301 is mounted on the first printed circuit board 31 in such a way that the heat transfer path to the nearest mounting portion 13 is the shortest among the electronic components mounted on the first printed circuit board 31. Here, the length of the heat transfer path from a certain electronic component to the nearest mounting portion 13 of that electronic component will be expressed in the form of L preceding the symbol of that electronic component. Taking Figure 8 as an example, the nearest mounting portion 13 to the first electronic component 301 is mounting portion 13-2, so the length of the heat transfer path from the first electronic component 301 to mounting portion 13-2 is L301. In other words, L301 represents the length of the heat transfer path from the first electronic component 301 to the first printed circuit board 31 → first mounting section 110 → first stage section 142 → second stage section 152 → side wall 112 → mounting section 13-2. Similarly, the nearest mounting section 13 to the second electronic component 309 is mounting section 13-5, and the length of the heat transfer path from the second electronic component 309 to mounting section 13-5 is L309. Therefore, in the first printed circuit board 30A, L301 is configured to be a shorter heat transfer path than L302 to L309.

[0029] The first electronic component 301 and the second electronic components 302-310 are components mounted on the first printed circuit board 31. In this example, the first printed circuit board 30A has a top surface ( Although electronic components are mounted only on the z-direction side, the control device 1 of this disclosure is not limited to this, and electronic components may be mounted on both sides of the first printed circuit board 30A, or electronic components may be mounted only on the lower surface of the first printed circuit board 30A. These points also apply to the second printed circuit board 40A and the third printed circuit board 50A, which will be described later.

[0030] <Second Printed Circuit Board 40A> Figure 9 is a perspective view of the second printed circuit board. Figure 10 is a top view of the base with the first and second printed circuit boards mounted on it. The second printed circuit board 40A has a second printed wiring board 41, a third electronic component 401, and fourth electronic components 402-415 mounted on the second printed wiring board 41. The second printed wiring board 41 is a wiring board made of an insulating material such as glass epoxy resin. In this example, the second printed wiring board 41 has a substantially rectangular flat shape. The second printed wiring board 41 has ends 41a, 41b along the longitudinal direction (y-axis direction) and ends 41c, 41d along the short direction (x-axis direction). In this disclosure, ends 41a, 41b are also referred to as "second ends 41a, 41b". The second ends 41a, 41b are mounted on the second mounting section 120.

[0031] The second printed circuit board 40A has holes 411a to 411n for fixing the second printed circuit board 40A to the base 11 or the first printed circuit board 31 or the third printed circuit board 51. The holes 411a to 411n are through holes for inserting fastening components. In this example, bolts are inserted into holes 411a, 411c, 411d, 411j, 411l, and 411m of the second printed circuit board 40A, and the second printed circuit board 41 is fixed to the bottom wall 111. A bolt is inserted from above into hole 411f, which fastens with a stud inserted into hole 311g, and the second printed circuit board 41 and the first printed circuit board 31 are fixed together. The holes 411b, 411e, 411g, 411h, 411i, 411k, and 411n are used to fix the second printed circuit board 41 to the bottom wall 111 by inserting studs, as well as to fix the first printed circuit board 31 to the second printed circuit board 41 and the second printed circuit board 41 to the third printed circuit board 51. The holes 411a to 411e and the holes 411j to 411n are located opposite the holes 120a to 120j provided in the second mounting section 120 when the second printed circuit board 40A is mounted on the base 11.

[0032] The upper ends of the studs inserted into the holes 311g to 311j of the first printed circuit board 31 have internal threads. A bolt is inserted into the hole 411f from the upper side of the second printed circuit board 41, and another stud is inserted into the holes 411g to 411i from the upper side of the second printed circuit board 41. These bolts and studs are fastened to the internal threads on the upper sides of the studs inserted into the holes 311g to 311j of the first printed circuit board 31, thereby fixing the first printed circuit board 31 and the second printed circuit board 41 together.

[0033] The third electronic component 401 is the component that emits the largest amount of heat among the electronic components mounted on the second printed circuit board 41. That is, the fourth electronic components 402 to 415 are electronic components that generate less heat than the third electronic component 401. In this example, the third electronic component 401 is mounted on the second printed circuit board 41 in such a way that the heat transfer path to the nearest mounting part 13 is the shortest among the electronic components mounted on the second printed circuit board 41. If we express the length of the heat transfer path from a certain electronic component to the nearest mounting part 13 of that electronic component in the same format as in the case of the first printed circuit board 30A, then in the second printed circuit board 40A, L401 is configured to have a shorter heat transfer path than L402 to L415.

[0034] The second ends 41a and 41b have holes 411a to 411e and 411j to 411n in positions opposite to the holes 120a to 120j when the second ends 41a and 41b are mounted on the second mounting section 120. The second printed circuit board 41 is fixed to the second mounting section 120 by inserting bolts into the holes 411a, 411c, 411d, 411j, 411l, and 411m. The second printed circuit board 41 is also fixed to the second mounting section 120 by inserting studs into the holes 411b, 411e, 411k, and 411n from the top side, and is used to fix the second printed circuit board 41 to the third printed circuit board 51. The second printed circuit board 41 is fixed to the first printed circuit board 31 by fastening studs inserted into holes 311h to 311j by inserting studs into holes 411g, 411h, and 411i from the top side, and is also used to fix the second printed circuit board 41 to the third printed circuit board 51. In this disclosure, the fastening components (bolts and studs in this example) inserted into the second mounting section 120 are referred to as "second fastening components 82". Therefore, the second ends 41a and 41b are mounted directly on a pair of second mounting sections 120, and each is fixed to the second mounting section 120 using second bolts 82.

[0035] The pair of second ends 41a and 41b are positioned to cover at least a portion of each of the pair of first ends 31a and 31b when viewed from the perspective shown in Figure 10, that is, when viewing the first printed circuit board 30A from the second printed circuit board 40A.

[0036] One end of a stud is inserted from the top side into holes 411b, 411e, 411g, 411h, 411i, 411k, and 411n. The other end (upper end) of the stud is female-threaded, and bolts are inserted from the top side into holes 511a, 511d, 511e, 511f, 511g, 511h, and 511k provided in the third printed circuit board 51, and used to fix the second printed circuit board 41 and the third printed circuit board 51. The male-threaded portion at the lower end of the studs inserted into 411g, 411h, and 411i from the top side of the second printed circuit board 41 is fastened with the female-threaded portion at the upper end of the studs inserted into 311h, 311i, and 311j, thereby fixing the first printed circuit board 31 and the second printed circuit board 41.

[0037] <Third Printed Circuit Board 50A> Figure 11 is a perspective view of the third printed circuit board. Figure 12 is a top view of Figure 2. Specifically, Figure 12 is a top view of the base with the first printed circuit board 30A, the second printed circuit board 40A, and the third printed circuit board 50A mounted on it. The third printed circuit board 50A has a third printed wiring board 51, a fifth electronic component 501, and sixth electronic components 502-507 mounted on the third printed wiring board 51. The third printed wiring board 51 is a wiring board made of an insulating material such as glass epoxy resin. In this example, the third printed wiring board 51 has a roughly square flat shape. When mounted on the base 11, the third printed wiring board 51 has ends 51a, 51b that are aligned in the same direction as the longitudinal direction of the base 11, and ends 51c, 51d that are aligned in the same direction as the short direction of the base 11. In this disclosure, the ends 51a and 51b will also be referred to as the "third ends 51a and 51b". The third ends 51a and 51b are mounted on the third mounting section 130.

[0038] The third printed circuit board 50A has holes 511a to 511k for fixing the third printed circuit board 50A to the base 11 or the second printed wiring board 41. The holes 511a to 511k are through holes for inserting fastening components. In this example, the third printed circuit board 50A is fixed to the bottom wall 111 by inserting bolts through the holes 511b, 511c, 511i, and 511j. The holes 511b, 511c, 511i, and 511j are located opposite the holes 130a to 130d provided in the third mounting section 130 when the third printed circuit board 50A is mounted on the base 11. In this disclosure, the fastening component (a bolt in this example) inserted into the third mounting section 130 is referred to as the "third fastening component 83". The third ends 51a and 51b are mounted directly on a pair of third mounting sections 130, and each is fixed to the third mounting section 130 using a third fastening component 83.

[0039] One end of a stud is inserted from the top into the holes 411b, 411e, 411g, 411h, 411i, 411k, and 411n of the second printed circuit board 41. The other end (upper end) of the stud is threaded, and a bolt is inserted from the top into the holes 511a, 511d, 511e, 511f, 511g, 511h, and 511k provided in the third printed circuit board 51, and used to fix the second printed circuit board 41 and the third printed circuit board 51 together.

[0040] The fifth electronic component 501 is the component that emits the largest amount of heat among the electronic components mounted on the third printed circuit board 51. That is, the sixth electronic components 502 to 507 are electronic components that generate less heat than the fifth electronic component 501. In this example, the fifth electronic component 501 is mounted on the third printed circuit board 51 in such a way that the heat transfer path to the nearest mounting part 13 is the shortest among the electronic components mounted on the third printed circuit board 51. If we express the length of the heat transfer path from a certain electronic component to the nearest mounting part 13 of that electronic component in the same format as in the case of the first printed circuit board 30A, then in the third printed circuit board 50A, L501 is configured to have a shorter heat transfer path than L502 to L507.

[0041] The third ends 51a and 51b have holes 511b, 511c, 511i, and 511j in positions facing the holes 130a to 130d when the third ends 51a and 51b are mounted on the third mounting section 130. The third printed circuit board 51 is fixed to the third mounting section 130 by inserting bolts, which are third fastening components 83, into the holes 511b, 511c, 511i, and 511j. In other words, the third ends 51a and 51b are mounted directly on a pair of third mounting sections 130, and each is fixed to the third mounting section 130 using the third fastening components 83.

[0042] The pair of third ends 51a and 51b are positioned to cover at least a portion of each of the pair of second ends 41a and 41b when viewed from the perspective shown in Figure 12, that is, when viewing the second printed circuit board 40A from the third printed circuit board 50A.

[0043] Bolts are inserted from the top side into the holes 511a, 511d, 511e, 511f, 511g, 511h, and 511k of the third printed circuit board 51. The upper ends of the studs inserted into the holes 411b, 411e, 411g, 411h, 411i, 411k, and 411n of the second printed circuit board 41 are female threads, and are fastened with the bolts inserted from the top side of the third printed circuit board 51, thereby fixing the second printed circuit board 41 and the third printed circuit board 51 together.

[0044] As previously described, the pair of second ends 41a and 41b are positioned to cover at least a portion of each of the pair of first ends 31a and 31b when viewed from the viewpoint shown in Figure 10, that is, when viewing the first printed circuit board 30A from the second printed circuit board 40A. The pair of third ends 51a and 51b are positioned to cover at least a portion of each of the pair of second ends 41a and 41b when viewed from the viewpoint shown in Figure 12, that is, when viewing the second printed circuit board 40A from the third printed circuit board 50A. As a result, the holes 110a to 110r, 120a to 120j, and 130a to 130d provided in the control device 1 are configured to be visible from the viewpoint shown in Figure 6B, i.e., when the first printed circuit board 30A, the second printed circuit board 40A, and the third printed circuit board 50A are housed in the base 11, and the bottom wall 111 is viewed from above the base 11. As a result, fastening components can be inserted directly from above into the control device 1, improving manufacturability. However, the control device 1 of this disclosure is not limited to this, and may be configured so that at least one of the holes 110a to 110r, at least one of the holes 120a to 120j, and at least one of the holes 130a to 130d are visible.

[0045] <How to assemble the control device 1> The control device 1 mounts the first printed circuit board 30A, which is connected to the flexible circuit board 33 on which the socket 34 is mounted, onto the bottom wall 111 of the base 11, as shown in Figure 5(1), by inserting the socket 34 into the hole 114a from the inside of the base 11. At this time, the first ends 31a and 31b are mounted facing the first mounting section 110. Fastening components such as bolts and studs are inserted into the predetermined positions described above to fix the first printed circuit board 30A to the base 11.

[0046] Next, as shown in Figure 5(2), the second printed circuit board 40A is mounted on the second mounting section 120. At this time, the second ends 41a and 41b are mounted facing the second mounting section 120. Fastening components such as bolts and studs are inserted into the predetermined positions described above to fix the second printed circuit board 40A to the base 11. The first printed circuit board 30A and the second printed circuit board 40A are also fixed together.

[0047] Next, as shown in Figure 5(3), the third printed circuit board 50A is mounted on the third mounting section 130. Fastening components, which are bolts, are inserted into the predetermined positions as described above to fix the third printed circuit board 50A to the base 11. The second printed circuit board 40A and the third printed circuit board 50A are also fixed together.

[0048] Finally, the base 11 is covered from above with the cover 18. As previously described, in this example, the base 11 and the cover 18 are fastened together with bolts and nuts. This completes the assembly of the control device 1. The assembled control device 1 has a layered structure in which the first printed circuit board 30A, the second printed circuit board 40A, and the third printed circuit board 50A are arranged to overlap at a predetermined distance from each other without touching, as shown in Figures 3 and 4.

[0049] The first ends 31a and 31b are mounted directly on a pair of first mounting sections 110, and each is fixed to the first mounting section 110 using a first fastening component 81. The second ends 41a and 41b are mounted directly on a pair of second mounting sections 120, and each is fixed to the second mounting section 120 using a second bolt 82. The third ends 51a and 51b are mounted directly on a pair of third mounting sections 130, and each is fixed to the third mounting section 130 using a third fastening component 83. The base 11 having the first mounting section 110, the second mounting section 120, and the third mounting section 130, and the mounting section 13 connected to the base 11, are made of an aluminum alloy, which has a higher thermal conductivity than materials such as resin. Therefore, the control device 1 of this disclosure can implement heat dissipation measures without providing a heat sink like those in Patent Document 1. Furthermore, since a heat sink is not required, there is no need for space to house a heat sink within the housing 10A. Therefore, the control device 1 of this disclosure can achieve miniaturization and weight reduction of the device while suppressing deterioration of cooling efficiency.

[0050] The base 11 has a plurality of mounting parts 13 made of aluminum alloy. The mounting parts 13 are attached to an external device, which is a controlled device. If the external device is a structure that is sufficiently larger than the control device 1 of this disclosure, it often has a sufficiently large heat capacity compared to the control device 1 of this disclosure, depending on the type of material, density, and specific heat. For this reason, it is possible to efficiently cool the controlled device by conducting the heat generated from the control device 1 to the controlled device via the mounting parts 13. Alternatively, if the controlled device to which the control device 1 is attached has a forced cooling function such as a fan, it is possible to efficiently cool the controlled device by conducting the heat generated from the control device 1 to the controlled device via the mounting parts 13.

[0051] At least one mounting portion 13 is provided on the outer surface of each of the side walls 112 and 113. Of the pair of first mounting portions 110, the pair of second mounting portions 120, and the pair of third mounting portions 130, one is provided near the inner surface of one of the side walls, and the other is provided near the inner surface of the other side wall. The heat from the first printed circuit board 30A, the second printed circuit board 40A, and the third printed circuit board 50A is efficiently transferred to the mounting portion 13 by minimizing the length of the heat transfer path, thereby enabling cooling measures at the mounting portion 13.

[0052] The first printed circuit board 30A, the second printed circuit board 40A, and the third printed circuit board 50A employ a hierarchical structure, as shown in Figures 3 and 4, where they overlap at a predetermined distance from each other without contact. The pair of second ends 41a and 41b are positioned to cover at least a portion of each of the pair of first ends 31a and 31b when viewed from the viewpoint in Figure 10, i.e., when viewing the first printed circuit board 30A from the second printed circuit board 40A. The pair of third ends 51a and 51b are positioned to cover at least a portion of each of the pair of second ends 41a and 41b when viewed from the viewpoint in Figure 12, i.e., when viewing the second printed circuit board 40A from the third printed circuit board 50A. The width of the base 11 is configured such that, when viewed from the viewpoint in Figure 1B, it narrows from a width equivalent to that of the cover 18 to the width of the bottom wall 111 by providing first and second stepped sections 142 and 143 and 152 and 153. In other words, the housing 10A is configured such that its lower end is narrower than its upper end. This configuration allows for a more flexible shape, rather than being limited to a rectangular box shape, as in Patent Document 1, for example. Therefore, the control device 1 can be made even smaller.

[0053] The first electronic component 301 is the component that emits the most heat among the electronic components mounted on the first printed circuit board 31, and is the component that requires the most heat dissipation measures among the first printed circuit board 30A. The first electronic component 301 is mounted on the first printed circuit board 31 in such a way that the heat transfer path to the nearest mounting part 13 is the shortest among the electronic components mounted on the first printed circuit board 31. Therefore, the first printed circuit board 30A can be efficiently equipped with heat dissipation measures.

[0054] The third electronic component 401 is the component that emits the largest amount of heat among the electronic components mounted on the second printed circuit board 41, and is the component that requires the most heat dissipation measures among the second printed circuit board 40A. The third electronic component 401 is mounted on the second printed circuit board 41 in such a way that the heat transfer path to the nearest mounting part 13 is the shortest among the electronic components mounted on the second printed circuit board 41. The fifth electronic component 501 is the component that emits the largest amount of heat among the electronic components mounted on the third printed circuit board 51, and is the component that requires the most heat dissipation measures among the third printed circuit board 50A. The fifth electronic component 501 is mounted on the third printed circuit board 51 in such a way that the heat transfer path to the nearest mounting part 13 is the shortest among the electronic components mounted on the third printed circuit board 51. Therefore, efficient heat dissipation measures can also be implemented for the second printed circuit board 40A and the third printed circuit board 50A. In this disclosure, the electronic component that emits the largest amount of heat among the electronic components mounted on the printed circuit board has been described, but the technology of this disclosure is not limited to this. In other words, a predetermined electronic component may be mounted on a printed circuit board in such a way that the heat transfer path to the nearest mounting portion 13 is the shortest compared to other electronic components.

[0055] The embodiments of the present disclosure have been described above. In this disclosure, the base 11 and the mounting portion 13 are made of an aluminum alloy with high thermal conductivity, but the material of the base 11 in this disclosure is not limited to an aluminum alloy, and other materials may be used as long as they have high thermal conductivity. Furthermore, it goes without saying that the above-described connecting body can be modified as appropriate without departing from the spirit of this disclosure. [Explanation of symbols]

[0056] 1. Control device 10A enclosure 11 Bass 110 First mounting section 110a~110r Hole 111 Bottom wall 111a Top side 111b Bottom side 111x recess 112,113 side wall 114 Front wall 114a Hole 115 Back wall 120 Second mounting section 120a~120j Hole 13 Mounting part 13a hole 130 Third mounting section 130a~130d Hole 142 Section 1 143 Section 1 152 Section 2 153 Section 2 16 Insertion part 162,163 Protrusion 18 Cover 30A First Printed Circuit Board 31. First Printed Circuit Board 31a, 31b (1st) end 31c,32d end 311a~311r Hole 301 First Electronic Components 302-310 Second Electronic Components 33 Flexible circuit board 34 sockets 40A Second Printed Circuit Board 41. Second Printed Circuit Board 41a, 41b (2nd) end 41c, 42d End 401 Third Electronic Components 402-415 Fourth Electronic Components 411a~411n Hole 50A Third Printed Circuit Board 51 Third Printed Circuit Board 51a, 51b (3rd) end 51c,51d End 501 Fifth Electronic Component 502-507 Sixth Electronic Component 511a~511k Hole 81 First fastening component 82 Second fastening component 83 Third fastening component

Claims

1. A control device comprising a first printed circuit board, a second printed circuit board, and an aluminum alloy housing that houses the first printed circuit board and the second printed circuit board, The housing comprises a pair of first mounting sections arranged side by side in the width direction, and a pair of second mounting sections arranged side by side in the width direction, separated in one direction intersecting the width direction of the pair of first mounting sections. The first printed circuit board is mounted directly on the pair of first mounting portions, and each has a pair of first ends that are fixed to the first mounting portions using fastening components. The second printed circuit board is mounted directly on the pair of second mounting sections and has a pair of second ends, each of which is fixed using fastening components. The pair of second ends are positioned to cover at least a portion of each of the pair of first ends when viewed from the second printed circuit board to the first printed circuit board. Control device.

2. The housing has multiple mounting parts made of aluminum alloy for attachment to an external device. The aforementioned plurality of mounting portions are provided connected to the outer surface between the upper and lower ends of the housing. The control device according to claim 1.

3. The enclosure further comprises a third printed circuit board housed within the aforementioned enclosure. The housing has a pair of third mounting portions that are provided separated from the second mounting portion in one direction and arranged side by side in the width direction, The third printed circuit board is mounted directly on the pair of third mounting portions and has a pair of third ends, each of which is fixed using fastening components. The pair of third ends are positioned to cover at least a portion of each of the pair of second ends when viewed from the third printed circuit board to the second printed circuit board. The control device according to claim 2.

4. The control device according to claim 3, wherein the plurality of mounting portions are provided on the outside of the housing, between the second printed circuit board and the third printed circuit board.

5. The mounting portion is provided at least once on the outer surface of each side wall of the housing. The pair of first mounting portions are provided such that one is located near the inner surface of one of the side walls, and the other is located near the inner surface of the other side wall. The pair of second mounting portions are provided such that one is located near the inner surface of one of the side walls, and the other is located near the inner surface of the other side wall. The pair of third mounting portions are provided such that one is located near the inner surface of one of the side walls, and the other is located near the inner surface of the other side wall. The control device according to claim 3 or 4.

6. The control device according to claim 5, wherein the housing is configured such that the lower end is narrower than the upper end.

7. The control device according to claim 5, wherein the first printed circuit board has a first electronic component and a second electronic component that generates less heat than the first electronic component mounted on it, and the first electronic component is mounted such that the heat transfer path to the nearest mounting portion is the shortest among the electronic components on the first printed circuit board.

8. The control device according to claim 5, wherein the second printed circuit board has a third electronic component and a fourth electronic component that generates less heat than the third electronic component mounted on it, and the third electronic component is mounted on the second printed circuit board such that the heat transfer path to the nearest mounting portion is the shortest among the electronic components of the second printed circuit board.

9. The control device according to claim 5, wherein the third printed circuit board has a fifth electronic component and a sixth electronic component that generates less heat than the fifth electronic component mounted on it, and the fifth electronic component is mounted such that the heat transfer path to the nearest mounting portion is the shortest among the electronic components of the third printed circuit board.

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