ELECTRONIC CONTROL DEVICE

Abstract

An electronic control device comprises: a circuit board with a printed circuit board carrying a wiring structure with a high-speed signal line, and an electronic component mounted on a first surface of the printed circuit board, the electronic component being connected to the high-speed signal line; a housing containing the circuit board; and a first thermally conductive element in direct contact with the electronic component and with the housing.The first thermally conductive element is arranged in such a way that it extends from an upper surface of the electronic component to the housing in a position in which the first thermally conductive element avoids a space above the high-speed signal line, and extends from the first surface of the circuit board to the housing while in contact with part of an outer peripheral surface of the electronic component.

Description

Technical area

[0001] The present invention relates to an electronic control device, in particular an electronic control device in which a circuit board is accommodated in a housing. Background of the invention

[0002] Generally, a vehicle such as an automobile incorporates multiple electronic control devices. An electronic control device (hereinafter referred to as an in-vehicle electronic control device) integrated into a vehicle has a structure in which a circuit board supporting electronic components is housed in a casing.

[0003] In recent years, the improvement of the functions of in-vehicle electronic control devices including electronic control devices for autonomous driving or advanced driving support systems has been underway, resulting in an increasing amount of heat generated by electronic components. When the temperature of an electronic component rises to a rated temperature or higher, causing deterioration of the electronic component's function, this may invite failure of the electronic control device. A method for suppressing a temperature rise of the electronic component caused by its heat generation is known. According to the method, heat generated by the electronic component is dissipated by using a thermal interface material (TIM) such as a heat-dissipating paste (see, for example, PTL 1).) to escape to the housing.

[0004] An electronic control device described in PTL 1 is designed such that a heat-dissipating gel (TIM) fills a gap between a mounting surface of a substrate carrying a heat-generating electronic component (e.g., a power MOSFET as a semiconductor element) and an opposite surface of a package, the opposite surface being opposite to the mounting surface that transfers heat generated by the electronic component to the package (see, for example, Fig. 18 of PTL 1). In other words, the heat-dissipating gel is arranged to completely cover the entire outer surface (a top surface and all the side surfaces) of the electronic component mounted on the substrate. Citation listPatent literature

[0005] PTL 1: JP 2011-023593 A Overview of the inventionTechnical problem

[0006] In an electronic control device for autonomous driving or an advanced driving support system, a heat-generating electronic component is sometimes provided as a high-functionality component that operates at a high speed, such as a system-on-chip (SoC) with a ball grid array (BGA) packaging structure. Such a high-functionality electronic component is often electrically connected to a high-speed signal line. In this specification, an electronic component that operates at an operating frequency of more than 100 MHz is defined as an electronic component capable of high-speed operation, and a signal line for transmitting a signal with a frequency of more than 100 MHz is defined as a high-speed signal line.

[0007] Consider a case where the technique described in PTL 1 is applied to a high-functionality electronic component capable of high-speed operation to improve its heat dissipation performance. In this case, the TIM is arranged to cover the entire outer surface (the top surface and the entire side surfaces) of the electronic component connected to the high-speed signal line on the substrate, raising concerns about deterioration in the quality of a high-frequency signal transmitted over the high-speed signal line and an increase in radiation noise.This is because placing the TIM covering the electronic component between the high-speed signal line on the substrate and the package creates a situation where the TIM increases the capacitance between the high-speed signal line and the package. This increase in capacitance causes a deterioration in the quality of the high-frequency signal and an increase in radiation interference. A decrease in the quality of the high-frequency signal and an increase in radiation interference raise concerns that the high functionality of the in-vehicle electronic control device will be reduced.

[0008] According to the technique described in PTL 1, a power MOSFET is cited as a heat-generating electronic component mounted on the substrate. Generally, the power MOSFET operates at a frequency below 100 MHz, which is assumed in this specification to be a frequency defined for high-speed operation. Therefore, this reduces the need to consider the above-mentioned problems: deterioration of the high-frequency signal quality and increase in radiation noise caused by the arrangement of the TIM, in order to improve the heat dissipation performance of the electronic component.

[0009] The present invention has been developed to solve the above problem, and an object of the present invention is to provide an electronic control device that can ensure the quality of a high-frequency signal and suppress radiation noise while maintaining heat dissipation performance. Solution to the problem

[0010] The present application provides several means for solving the above problem. As an example of the means for solving the above problem, an electronic control device includes: a circuit board including a printed circuit board supporting a wiring pattern with a high-speed signal line, and an electronic component mounted on a first surface of both surfaces of the printed circuit board, the electronic component being electrically connected to the high-speed signal line; a casing housing the circuit board; and a first heat-conducting member in direct contact with the electronic component and the casing.The electronic component has a bottom surface facing the first surface of the circuit board, an upper surface disposed opposite the bottom surface, and an outer peripheral surface connected to an outer edge of the bottom surface and to an outer edge of the upper surface. The first heat-conducting member is arranged in such a manner that it extends from the top surface of the electronic component to the housing, and extends from the first surface of the circuit board to the housing while contacting a part of the outer peripheral surface of the electronic component in a position where the first heat-conducting member avoids a space above the high-speed signal line. Advantageous effects of the invention

[0011] According to the present invention, by disposing the first heat-conducting member in such a way that it is brought into contact with the upper surface of the electronic component and with a part of the outer peripheral surface, heat dissipation performance is maintained. By disposing the first heat-conducting member in a position where it avoids the high-speed signal line, an increase in capacitance between the high-speed signal line and the housing caused by the arrangement of the first heat-conducting member can be avoided. Therefore, the quality of a high-frequency signal is ensured and radiation noise is suppressed while maintaining heat dissipation performance.

[0012] Problems, configurations and effects other than those described above will be made clear by the following description of embodiments. Brief description of the drawings [ Fig. 1] Fig. 1 is a schematic perspective view of an electronic control device according to an embodiment of the present invention, showing the electronic control device in its disassembled state. [ Fig. 2] Fig. 2 is a schematic cross-sectional view of an electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a first embodiment. [ Fig. 3] Fig. 3 is a schematic plan view of the electronic component of the circuit board and the peripheral structure around the electronic component in the electronic control device according to the first embodiment. [ Fig. 4] Fig. Fig. 4 is a schematic perspective view of the electronic component of the circuit board and the peripheral structure around the electronic component in the electronic control device according to the first embodiment shown in Fig. 3 is shown. [ Fig. 5] Fig. 5 is a schematic plan view of the electronic component of the circuit board and a peripheral structure around the electronic component in the electronic control device of a comparative example compared with the electronic control device according to the first embodiment. [ Fig. 6] Fig. 6 is a schematic cross-sectional view (a cross section taken along the upper surface of the electronic component) showing the arrangement of a TIM in contact with side surfaces of the electronic component of a circuit board in an electronic control device according to a first modification of the first embodiment. [ Fig. 7] Fig. 7 is a schematic cross-sectional view (a cross section taken along the upper surface of the electronic component) showing the arrangement of a TIM in contact with the side surfaces of the electronic component of a circuit board in an electronic control device according to a second modification of the first embodiment. [ Fig. 8] Fig. 8 is a schematic cross-sectional view (a cross section taken along the upper surface of the electronic component) showing the arrangement of a TIM in contact with a side surface of the electronic component of a circuit board in an electronic control device according to a third modification of the first embodiment. [ Fig. 9] Fig. 9 is a perspective view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a second embodiment of the present invention. [ Fig. 10] Fig. 10 is a schematic bottom view of the electronic component of a circuit board and the peripheral structure around the electronic component in the electronic control device according to the second embodiment. [ Fig. 11] Fig. 11 is a perspective view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a first example of a first modification of the second embodiment. [ Fig. 12] Fig. 12 is a perspective view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a second example of the first modification of the second embodiment. [ Fig. 13] Fig. 13 is a cross-sectional view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a first example of a second modification of the second embodiment. [ Fig. 14] Fig. 14 is a cross-sectional view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a second example of the second modification of the second embodiment. [ Fig. 15] Fig. 15 is a schematic diagram showing an arrangement relationship between the electronic component of the circuit board and heat-conducting paths (through holes) in an electronic control device according to a first example of a third modification of the second embodiment. [ Fig. 16] Fig. 16 is a schematic diagram showing an arrangement relationship between the electronic component of the circuit board and heat-conducting paths (through holes) in an electronic control device according to a second example of the third modification of the second embodiment. [ Fig. 17] Fig. 17 is a contour diagram showing a heat flow rate at the circuit board in the electronic control device according to the first example of the third modification of the second embodiment. [ Fig. 18] Fig. 18 is a schematic cross-sectional view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a third embodiment of the present invention. [ Fig. 19] Fig. 19 is a schematic perspective view of an appearance of an electronic control device according to a fourth embodiment of the present invention. [ Fig. 20] Fig. 20 is a schematic perspective view of an appearance of an electronic control device according to a fifth embodiment of the present invention. Description of the embodiments

[0013] Embodiments of an electronic control device of the present invention will be described below with reference to the drawings. In the present description and the drawings, components that are substantially identical in function or configuration are denoted by the same reference numerals to avoid unnecessary description. [First embodiment]

[0014] A configuration and a structure of an electronic control device according to a first embodiment will first be described with reference to Fig. 1 described. Fig. 1 is a schematic perspective view of the electronic control device according to the embodiment, showing the electronic control device in its disassembled state.

[0015] In Fig. 1, an electronic control device 1 according to this embodiment is a control device that performs high-speed communication. The electronic control device 1 is installed, for example, in a vehicle (not shown) and is used as a control device that controls the vehicle or assists in driving. The electronic control device 1 can also be used as a control device for controlling a millimeter-wave radar, an in-vehicle camera, or the like. A control target of the electronic control device 1 is not limited to a specific object.

[0016] The electronic control device 1 contains a circuit board 2, which forms an electronic circuit, and a housing 3 in which the circuit board 2 is housed.

[0017] The circuit board 2 includes a printed circuit board 11 having a wiring structure (not shown) with a high-speed signal line 12, which will be described later (see Fig. 3, which will be referred to later), and a plurality of electronic components 14 mounted on the printed circuit board 11. The printed circuit board 11 has two surfaces, i.e., a first surface 11a and a second surface 11b, on which electronic components can be mounted. The printed circuit board 11 can be designed either as a single-sided board with a wiring structure formed on only one of the first surface 11a and the second surface 11b, or as a double-sided board with a wiring structure formed on both surfaces. The printed circuit board 11 is formed, for example, from a rigid board containing glass epoxy as a base material.The electronic components 14 include, for example, various elements such as a resistor, a capacitor, a diode, a storage element, and a switching element, a connector 15, and a heat-generating electronic component 16 that requires heat dissipation. In the embodiment shown in FIG. Fig. In the circuit board 2 shown in Figure 1, the heat-generating electronic component 16 is mounted on the first surface 11a of the printed circuit board 11. In other words, the first surface 11a of the printed circuit board 11 is the surface supporting the heat-generating electronic component 16.

[0018] The heat-generating electronic component 16 according to this embodiment is an electronic component capable of operating at a high-speed operating frequency ranging from several hundred MHz to several GHz. The electronic component 16 capable of high-speed operation (hereinafter referred to as a "high-speed electronic component" in some cases) consumes a large amount of power when performing high-speed processing. Its power consumption can reach several tens of watts and, as a result, generates a lot of heat.The high-speed electronic component 16 is, for example, a high-functionality component such as a microcontroller with an integrated processor, such as a central processing unit (CPU) or a graphics processing unit (GPU), an integrated circuit (IC) chip, or a semiconductor chip. The electronic component 16, as a high-functionality component, is capable of high-speed communication with various electronic components, such as a DDR memory and a serializer with a signal conversion function.As another example of the high-speed electronic component 16, for example, a memory that operates fast enough to enable high-speed communication with the aforementioned microcontroller containing the processor via a high-speed communication line is also considered a high-speed electronic component 16. The high-speed electronic component 16 generates a lot of heat and therefore requires heat dissipation measures. A specific configuration of the high-speed electronic component 16 will be described later.

[0019] The housing 3 includes, for example, a housing body 21 forming an interior space accommodating the circuit board 2, and a cover 22 closing an opening of the housing body 21, the opening allowing the circuit board 2 to be inserted into the housing body 21. The housing body 21 has an opposite surface 21a (see Fig. 2, which will be referred to later), which is opposite to the first surface 11a (the surface supporting the electronic component 16) of the printed circuit board 11. The cover 22 is arranged opposite to the second surface 11b of the printed circuit board 11. For example, the case body 21 and the cover 22 are formed of a metal material from the viewpoint of better heat dissipation performance. The case body 21 with the circuit board 2 placed therein and the cover 22 are connected to each other using a plurality of screws 23.

[0020] A configuration of the high-speed electronic component and a heat dissipation structure for the high-speed electronic component in the electronic control device according to the first embodiment will then be described with reference to FIG. Fig. 2 to 4. Fig. 2 is a schematic cross-sectional view of the electronic component of the circuit board and a peripheral structure around the electronic component in the electronic control device according to the first embodiment. Fig. 3 is a schematic plan view of the electronic component of the circuit board and the peripheral structure around the electronic component in the electronic control device according to the first embodiment. Fig. Fig. 4 is a schematic perspective view of the electronic component of the circuit board and the peripheral structure around the electronic component in the electronic control device according to the first embodiment shown in Fig. 3 is shown.

[0021] The electronic component 16 capable of high-speed operation is structured such that, for example, an IC chip 32 serving as a heat source is incorporated into a semiconductor package having a ball grid array (BGA) structure, as in the example of Fig. 2. More specifically, the circuit component 16 includes the IC chip 32 placed on a substrate 31, solder balls 33 that enable the IC chip 32 to be electrically connected to a wiring structure of the circuit board 2, a lid 34 that covers the IC chip 32 to protect it, and a sealing resin 35 that fills a space within the lid 34 to seal the IC chip 32. The electronic component 16 is formed into a flat, rectangular parallelepiped having a rectangular shape when viewed from a side where an upper surface 16b is located, which will be described later. For example, as shown in FIGS. Fig. As shown in FIGS. 2 to 4, an outer surface of the high-speed electronic component 16 includes a lower surface 16a closer to the solder balls 33 and facing the first surface 11a of the printed circuit board 11, an upper surface 16b opposite the lower surface 16a, and an outer peripheral surface 16c connected to an outer edge of the lower surface 16a and an outer edge of the upper surface 16b. The upper surface 16b of the electronic component 16 is opposite the opposite surface 21a of the case body 21 of the case 3. The outer peripheral surface 16c of the electronic component 16 is composed of four side surfaces.

[0022] As in the Fig. 3 and Fig. As shown in Figure 4, the electronic component 16 capable of high-speed processing is connected to the high-speed signal line 12 (a part of the wiring structure) on the printed circuit board 11. The high-speed signal line 12 is configured as a signal line capable of transmitting a high-frequency signal from several hundred MHz to several GHz. The high-speed signal line 12 extends, for example, from two side surfaces 16c out of four side surfaces 16c of the electronic component 16, with the two side surfaces 16c being arranged opposite each other. More specifically, the high-speed signal line 12 extends from a region on each side surface 16c, the region being near a corner of the electronic component 16.

[0023] In the high-speed electronic component 16, the IC chip 32 generates heat due to its high-speed operation, which requires a heat dissipation measure. For this reason, the outer surface of the high-speed electronic component 16, as shown in the Fig. 2 to 4, the housing 3 is thermally connected to the housing body 21 via a thermally conductive member 40. Specifically, the thermally conductive member 40 is in direct contact with the electronic component 16 and the housing body 21 and is therefore thermally connected to the electronic component 16 and the housing body 21. The thermally conductive member 40 thus has a function of transferring the heat generated by the electronic component 16 to the housing body 21. The thermally conductive member 40 is made of a resin to which a thermally conductive filler is added. For example, a thermal interface material (TIM) such as a heat-dissipating paste or a thermally conductive sheet composed mainly of silicone, acrylic, epoxy, or urethane resin is used as the thermally conductive member 40.

[0024] As in the Fig. 3 and Fig. 4, the heat-conducting member 40 of this embodiment is arranged in such a manner as to be in contact with the upper surface 16b and a part of the side surfaces 16c of the outer surface of the electronic component 16 in a position in which the heat-conducting member 40 avoids a space above the high-speed signal line 12 of the printed circuit board 11.Specifically, the thermally conductive member 40 includes, for example, a conductive upper surface portion 41 arranged to extend from the upper surface 16b of the electronic component 16 to the opposite surface 21a of the case body 21, and four conductive side surface portions 42 each arranged to extend from the printed circuit board 11 to the opposite surface 21a of the case body 21 while contacting a central portion (a portion) of the corresponding side surface of the four side surfaces 16c of the electronic component 16. The conductive upper surface portion 41 contacts the upper surface 16b of the electronic component 16 in such a manner as to include the entire area of ​​an orthogonal projection of the IC chip 32 onto the upper surface 16b of the electronic component 16.In a view from a side where the upper surface 16b of the electronic component 16 is located, the conductive side surface parts 42S are composed of first conductive side surface parts 42a formed into substantially semi-elliptical shapes, each protruding from central parts of two side surfaces 16c of the electronic component 16, wherein the high-speed signal line 12 does not extend from the two side surfaces 16c, and second conductive side surface parts 42b formed into substantially semi-elliptical shapes, each protruding from central parts of the other two side surfaces 16c of the electronic component 16, wherein the high-speed signal line 12 extends from the other two side surfaces 16c.Each second conductive side surface part 42b is arranged in such a manner as to be in contact with the central part of the side surface 16c, the central part being a position where the second conductive side surface part 42b avoids a space above the high-speed signal line 12, but is not in contact with one end of the side surface 16c, one end of which lies on the high-speed signal line 12.

[0025] The effects of the heat-conducting element in the electronic control device according to the first embodiment will then be described with reference to an electronic control device of a comparative example. First, a heat dissipation structure of the electronic control device of the comparative example will be described with reference to Fig. 5 described. Fig. Fig. 5 is a schematic plan view of the electronic component of the circuit board and a peripheral structure around the electronic component in the electronic control device of the embodiment compared with the electronic control device according to the first embodiment. Fig. 5, the components are identified by the same reference numerals as those shown in the Fig. 1 to 4 are the same as those shown in the Fig. 1 to 4 and are therefore not described in detail in the further description.

[0026] An electronic control device 100 of the Fig. The comparative example shown in Figure 5 is the same as the electronic control device 1 of this embodiment in the configuration and structure of the circuit board 2 and the housing 3, but differs from the electronic control device 1 of this embodiment in the heat dissipation structure. Specifically, in the electronic control device 100 of the comparative example, the entire outer surface of the electronic component 16 mounted on the first surface 11a of the printed circuit board 11 of the circuit board 2 is thermally connected to the housing body 21 (in Fig. 5 not shown) of the housing 3. In other words, the heat-conducting member 140 is in contact with the entire upper surface 16b and the entire four side surfaces 16c (the entire outer peripheral surface) of the electronic component 16. In particular, the heat-conducting member 140 has, for example, a conductive upper surface part 141 arranged in such a way that it extends from the upper surface 16b of the electronic component 16 to the opposite surface 21a (in Fig. 5 not shown) of the case body 21, and conductive side surface parts 142 arranged in such a manner as to extend from the first surface 11a of the printed circuit board 11 to the opposite surface 21a of the case body 21 while being in contact with all four side surfaces 16c of the electronic component 16. As a result, in the electronic control device 100 of the comparative example, a part of the conductive side surface parts 142 of the heat-conducting member 140 is located in a space above the high-speed signal line 12 of the printed circuit board 11. The material of the heat-conducting member 140 in the electronic control device 100 of the comparative example is the same as the material of the heat-conducting member 40 in the electronic control device 1 of this embodiment.

[0027] Effects of the heat-conducting element in the electronic control device according to the first embodiment will then be described based on the effects exerted by the heat-conducting element during the operation of the electronic control device of the comparative example, with reference to the Fig. 2 to 5.

[0028] During operation of the electronic control device 100 of the Fig. In the comparative example shown in Figure 5, the electronic component 16 performs high-speed communication with another electronic component. For example, if the electronic component 16 is a high-functionality component, it performs high-speed communication with a memory via the high-speed signal line 12 on the printed circuit board 11. When performing such high-speed communication, various electronic components 14 mounted on the printed circuit board 11 (see Fig. 1), as well as the electronic component 16, heat, which causes the temperature of the electronic control device 100 of the comparative example to rise. At this time, heat from the electronic component 16 is transferred from the entire upper surface 16b of the electronic component 16 to the conductive upper surface part 141 of the heat-conducting member 140, and is transferred from the entire four side surfaces 16c of the electronic component 16 to the conductive side surface parts 142 of the heat-conducting member 140. Heat transferred to the conductive upper surface part 141 of the heat-conducting member 140 and to the conductive side surface parts 142 of the heat-conducting member 140 is dissipated by the housing body 21 (see Fig. 1) of the housing 3 to the outside of the housing 3 and is also transmitted to the circuit board 11. In the electronic control device 100 of the comparative example, a heat dissipation effect can be improved by the heat-conducting member 140 because the heat-conducting member 140 is arranged in such a manner as to be in contact with the entire top surface 16b and the entire four side surfaces 16c of the electronic component 16.

[0029] However, in the electronic control device 100 of the comparative example, a portion of the conductive side surface portions 142 of the heat-conducting member 140 occupies the space above the high-speed signal line 12 of the printed circuit board 11. This arrangement of the heat-conducting member 140 increases a capacitance between the high-speed signal line 12 and the case body 21. A capacitance C is given by the following equation (1). C=ε⋅S / L

[0030] In equation (1), ε denotes a relative dielectric constant, S represents the area of ​​the high-speed signal line 12 in a region where the heat-conducting member 140 is arranged, and L denotes a distance from the high-speed signal line 12 to the case body 21. The relative dielectric constant of air is 1, and the relative dielectric constant of the heat-conducting member 140 is, for example, about 8. This means that the relative dielectric constant of the heat-conducting member 140 is about 8 times that of air.

[0031] Thus, in the electronic control device 100 of the comparative example, the capacitance between the high-speed signal line 12 of the printed circuit board 11 and the housing body 21 increases due to the arrangement of the heat-conducting member 140. As a result, the quality of a high-frequency signal transmitted to the high-speed signal line 12 may deteriorate, and radiation noise may increase. If the quality of the high-frequency signal deteriorates or radiation noise increases, there is a concern that the high functionality of the electronic control device 100 may deteriorate.

[0032] However, in the electronic control device 1 according to this embodiment, the heat-conducting member 40 is arranged in such a manner that it extends from the first surface 11a of the printed circuit board 11 to the case body 21 of the case 3, in a position where the heat-conducting member 40 avoids the space above the high-speed signal line 12, while being in contact with a part of the outer peripheral surface 16c of the electronic component 16. As a result, the heat-conducting member 40 is not arranged in a region between the high-speed signal line 12 and the case body 21, and only the air is present in the region, in which case, a capacitance in the region does not increase.It is therefore unnecessary to worry about a decrease in the quality of the high-frequency signal transmitted through the high-speed signal line 12 and an increase in radiation noise resulting from the arrangement of the heat-conducting member 40.

[0033] Furthermore, according to this embodiment, the heat-conducting member 40 is arranged in such a manner that it contacts the upper surface 16b of the electronic component 16 and also a part of each of the four side surfaces 16c of the electronic component 16. As a result, heat of the electronic component 16 is transferred from the upper surface 16b and the four side surfaces 16c to the heat-conducting member 40, and therefore, the heat dissipation performance can be maintained.

[0034] In this embodiment, the heat-conducting member 40 is arranged in such a manner that it contacts a portion of each of the four side surfaces 16c of the electronic component 16. The heat-conducting member 40 arranged in the above manner enables a reduction in the amount of use of the heat-conducting member 40 compared to the heat-conducting member 140 arranged in such a manner that it contacts all four side surfaces 16c of the electronic component 16 in the electronic control device 100 of the comparative example. [Modifications of the first embodiment]

[0035] Electronic control devices according to modifications of the first embodiment will then be described with reference to the Fig. 6 to 8 described. Fig. 6 is a schematic cross-sectional view (a cross section taken along the upper surface of the electronic component) showing the arrangement of a TIM in contact with side surfaces of the electronic component of a circuit board in an electronic control device according to a first modification of the first embodiment. Fig. 7 is a schematic cross-sectional view (a cross section taken along the upper surface of the electronic component) showing the arrangement of a TIM in contact with side surfaces of the electronic component of a circuit board in an electronic control device according to a second modification of the first embodiment. Fig. 8 is a schematic cross-sectional view (a cross section taken along the upper surface of the electronic component) showing the arrangement of a TIM in contact with a side surface of the electronic component of a circuit board in an electronic control device according to a third modification of the first embodiment.

[0036] The first modification of the first embodiment, wherein the first modification in Fig. 6 differs from the first embodiment in that the arrangement of a high-speed signal line 12A connected to the high-speed electronic component 16 on the printed circuit board 11 of a circuit board 2A differs from the arrangement of the high-speed signal line in the first embodiment, and the structure of a heat-conducting member 40A differs from the structure of the heat-conducting member in the first embodiment. Specifically, the high-speed signal line 12A extends from two adjacent side surfaces 16c of the four side surfaces 16c of the electronic component 16. A part of the high-speed signal line 12A extends from the central part of one of the adjacent side surfaces 16c of the electronic component 16.The other part of the high-speed signal line 12A extends from the vicinity of a corner of the other of the adjacent side surfaces 16c of the electronic component 16. According to the arrangement of the high-speed signal line 12A on the printed circuit board 11, the heat-conducting member 40A is arranged in such a manner that it extends from the first surface 11a of the printed circuit board 11 to the case body 21 of the case 3 while being in contact with a part of the outer peripheral surface 16c of the electronic component 16, in a position in which the heat-conducting member 40A avoids the high-speed signal line 12A.Specifically, the thermally conductive member 40A includes the conductive upper surface portion 41 (not shown) and conductive side surface portions 42A arranged in such a manner as to extend from the first surface 11a of the printed circuit board 11 to the case body 21 of the case 3 while contacting the respective central portions of the side surfaces 16c disposed opposite to each other, the side surfaces 16c being included in the four side surfaces 16c of the electronic component 16. The thermally conductive member is not arranged on a side surface 16c of the electronic component 16 having the high-speed signal line 12A extending from the central portion of the side surface 16c.

[0037] The second modification of the first embodiment, wherein the second modification in Fig. 7 differs from the first embodiment in that the arrangement of a high-speed signal line 12B connected to the high-speed electronic component 16 on the printed circuit board 11 of a circuit board 2B differs from the arrangement of the high-speed signal line of the first embodiment, and the structure of a heat-conducting member 40B differs from the structure of the heat-conducting member of the first embodiment. Specifically, the high-speed signal line 12B extends from the respective central parts of two adjacent side surfaces 16c of the four side surfaces 16c of the electronic component 16.According to the arrangement of the high-speed signal line 12B on the printed circuit board 11, the heat-conducting member 40B is arranged in such a manner that it extends from the first surface 11a of the printed circuit board 11 to the case body 21 of the case 3 while being in contact with a part of the outer peripheral surface 16c of the electronic component 16, in a position in which the heat-conducting member 40B avoids the high-speed signal line 12B.Specifically, the thermally conductive member 40B includes the conductive upper surface portion 41 (not shown) and conductive side surface portions 42B arranged in such a manner as to extend from the first surface 11a of the printed circuit board 11 to the case body 21 of the case 3 while contacting the entirety of two side surfaces 16c that do not have the high-speed signal line 12B extending therefrom and that are adjacent to each other, the side surfaces 16c being included in the four side surfaces 16c of the electronic component 16. The thermally conductive member is not arranged on side surfaces 16c of the electronic component 16 that have the high-speed signal line 12A extending from the side surfaces 16c.

[0038] The third modification of the first embodiment, wherein the third modification in Fig. 8 differs from the first embodiment in that the arrangement of a high-speed signal line 12C connected to the high-speed electronic component 16 on the printed circuit board 11 of a circuit board 2C differs from the arrangement of the high-speed signal line in the first embodiment, and the structure of a heat-conducting member 40C differs from the structure of the heat-conducting member in the first embodiment. Specifically, the high-speed signal line 12C extends from the respective central parts of two oppositely disposed side surfaces 16c, the two side surfaces 16c being included in the four side surfaces 16c of the electronic component 16.According to the arrangement of the high-speed signal line 12C on the printed circuit board 11, the heat-conducting member 40C is arranged in such a manner that it extends from the first surface 11a of the printed circuit board 11 to the case body 21 of the case 3 while being in contact with a part of the outer peripheral surface 16c of the electronic component 16 in a position in which the heat-conducting member 40C avoids the high-speed signal line 12C.Specifically, the thermally conductive member 40C includes the conductive upper surface portion 41 (not shown) and a conductive side surface portion 42C arranged in such a manner as to extend from the first surface 11a of the printed circuit board 11 to the case body 21 of the case 3 while contacting the entirety of one side surface 16c from which the high-speed signal line 12B does not extend, the one side surface 16c being included in the four side surfaces 16c of the electronic component 16. The thermally conductive member is not arranged on the side surfaces 16c of the electronic component 16 from which the high-speed signal line 12C extends.

[0039] According to the arrangement of each of the high-speed signal lines 12A, 12B, and 12C on the printed circuit board 11, each of the heat-conducting members 40A, 40B, and 40C of the first, second, and third modifications is arranged in such a manner as to extend from the first surface 11a of the printed circuit board 11 to the case body 21 of the case 3 while being in contact with a part of the outer peripheral surface 16c of the electronic component 16, in a position in which each of the heat-conducting members 40A, 40B, and 40C avoids the space above the corresponding one of the high-speed signal lines 12A, 12B, and 12C.Therefore, as in the case of the first embodiment, it is unnecessary to worry about a decrease in the quality of the high-frequency signal transmitted through each of the high-speed signal lines 12A, 12B, and 12C and an increase in radiation noise due to the arrangement of each of the heat-conducting members 40A, 40B, and 40C.

[0040] Furthermore, the heat-conducting member 40A of the first modification is arranged in such a manner that it contacts the upper surface 16b of the electronic component 16 and also a part of each of two of the four side surfaces 16c of the electronic component 16. As a result, heat of the electronic component 16 is transferred from the upper surface 16b and the two side surfaces 16c, and therefore, the heat dissipation performance can be maintained.Since the heat-conducting member 40A is arranged in such a manner as to be in contact with a part of each of the two side surfaces of the four side surfaces 16c of the electronic component 16, a usage amount of the heat-conducting member 40A can be reduced compared with the case of using the heat-conducting member 40A in contact with a part of each side surface of the four side surfaces 16c of the electronic component 16 according to the first embodiment.

[0041] The heat-conducting member 40B of the second modification is arranged in such a manner that it is in contact with the upper surface 16b of the electronic component 16 and also with the entirety of two side surfaces of the four side surfaces 16c of the electronic component 16. As a result, heat of the electronic component 16 is dissipated from the upper surface 16b and the entirety of the two side surfaces 16c, and therefore, the heat dissipation performance can be maintained.

[0042] The heat-conducting member 40C of the third modification is arranged in such a manner that it contacts the upper surface 16b of the electronic component 16 and also the entirety of one side surface of the four side surfaces 16c of the electronic component 16. As a result, heat of the electronic component 16 is transferred from the upper surface 16b and the entirety of the one side surface 16c, and therefore, the heat dissipation performance can be maintained.

[0043] The electronic control device 1 of the first embodiment and its modifications include: circuit boards 2, 2A, 2B, and 2C having printed circuit boards 11 (circuit boards) including wiring patterns with high-speed signal lines 12, 12A, 12B, and 12C, and electronic components 16 mounted on first surfaces 11a of both surfaces of the printed circuit boards 11 (circuit boards), the electronic components 16 being electrically connected to the high-speed signal lines 12, 12A, 12B, and 12C, respectively; cases 3 accommodating the circuit boards 2, 2A, 2B, and 2C, respectively; and heat-conducting members 40, 40A, 40B, and 40C (first heat-conducting members) in direct contact with the electronic components 16 and the cases 3, respectively.The electronic component 16 has the lower surface 16a facing the first surface 11a of the printed circuit board 11 (circuit board), the upper surface 16b disposed opposite to the lower surface 16a, and the outer peripheral surface 16c connected to the outer edge of the lower surface 16a and to the outer edge of the upper surface 16b. Each of the heat-conducting members 40, 40A, 40B, and 40C (first heat-conducting members) is arranged in such a manner as to extend from the upper surface 16b of the electronic component 16 to the housing 3, and extend from the first surface 11a of the printed circuit board 11 (circuit board) to the housing 3 while contacting a part of the outer peripheral surface 16c of the electronic component 16 in a position where the heat-conducting member avoids the corresponding one of the high-speed signal lines 12, 12A, 12B, and 12C.

[0044] According to this configuration, the heat dissipation performance is maintained by arranging each of the heat-conducting elements 40, 40A, 40B, and 40C (first heat-conducting elements) in such a manner that the heat-conducting element is brought into contact with the upper surface 16b of the electronic component 16 and with a part of the outer peripheral surface 16c, and by arranging each of the heat-conducting elements 40, 40A, 40B, and 40C (first heat-conducting elements) in a position in which the heat-conducting element avoids a space above the corresponding high-speed signal line 12, 12A, 12B, and 12C, an increase in the capacitance between each of the high-speed signal lines 12, 12A, 12B, and 12C and the housing 3 caused by the arrangement of each of the heat-conducting elements 40, 40A, 40B, and 40C (first heat-conducting elements) should be avoided.Therefore, the quality of a high-frequency signal is ensured and radiation interference is suppressed while maintaining heat dissipation capability.

[0045] The electronic component 16 of the electronic control device 1 according to the first embodiment is rectangular in shape when viewed from the side where the upper surface 16b is located, and has four side surfaces forming the outer peripheral surface 16c. The heat-conducting member 40 (first heat-conducting member) is arranged in such a manner that, in the position where the heat-conducting member 40 avoids the space above the high-speed signal line 12, it extends from the first surface 11a of the printed circuit board 11 (circuit board) to the housing 3 while contacting a part of each of the four side surfaces 16c of the electronic component 16.

[0046] According to this configuration, heat of the electronic component 16 is transferred from the top surface 16b and each of the four side surfaces 16c to the heat-conducting member 40 (first heat-conducting member), and therefore, the heat dissipation performance can be improved compared to a case where the heat-conducting member 40 (first heat-conducting member) is not in contact with any of the four side surfaces 16c of the electronic component 16.

[0047] In the electronic control device 1 according to the first embodiment, the electronic component includes the IC chip 32 (chip), which is an integrated heat source. The heat-conducting member 40 (first heat-conducting member) contacts the upper surface 16b of the electronic component 16 in such a manner that it covers the entire area of ​​an orthogonal projection of the IC chip 32 (chip) onto the upper surface 16b of the electronic component 16.

[0048] With this configuration, the thermally conductive member 40 (first thermally conductive member) is brought into contact with a region of the upper surface 16b of the electronic component 16, which region reaches a relatively high temperature due to the heat from the IC chip 32 (chip) as a heat source. The heat dissipation performance of the thermally conductive member 40 (first thermally conductive member) can therefore be improved. [Second embodiment]

[0049] An electronic control device according to a second embodiment of the present invention will then be described with reference to the Fig. 9 and Fig. 10 described. Fig. 9 is a perspective view of the electronic component of a circuit board and a peripheral structure around the electronic component in the electronic control device according to the second embodiment of the present invention. Fig. 10 is a schematic bottom view of the electronic component of the circuit board and the peripheral structure around the electronic component in the electronic control device according to the second embodiment.

[0050] An electronic control device 1D according to the second embodiment shown in the Fig. 9 and Fig. 10 differs from the first embodiment mainly in that a thermally conductive member 50 is arranged across the printed circuit board 11 of the circuit board 2D opposite the thermally conductive member 40, and that thermally conductive paths 13 for thermally connecting the thermally conductive member 50 to the thermally conductive member 40 are provided on the printed circuit board 11 of the circuit board 2D. Other structural elements of the electronic control device 1D according to the second embodiment are the same as those of the electronic control device 1 according to the first embodiment and are therefore omitted from the further description.

[0051] Specifically, the thermally conductive paths 13 of the circuit board 2D are through-holes penetrating the printed circuit board 11 from its first surface 11a to its second surface 11b, and whose inner surfaces are covered with a printed circuit plating. The thermally conductive paths 13 are arranged at positions where the thermally conductive paths 13 can be thermally connected to the thermally conductive element 40 on one side of the housing body 21, that is, in areas where the conductive side surface portions 42 of the thermally conductive element 40 are in contact with the first surface 11a of the printed circuit board 11. For example, four thermally conductive paths 13 are arranged in such a manner that they are each thermally connected to the conductive side surface portions 42 in contact with the side surfaces 16c of the electronic component 16.

[0052] The thermally conductive member 50 is arranged in such a manner that it extends from the second surface 11b of the printed circuit board 11 of the circuit board 2D to a protrusion 22a on the cover 22 of the housing 3. The thermally conductive member 50 on one side of the cover 22 is made of a resin to which a thermally conductive filler is added, like the thermally conductive member 40 on the side of the housing body 21. As the thermally conductive member 50, for example, a thermal interface material (TIM) such as thermal grease or a thermally conductive sheet is used. The heat-conducting member 50 on the cover 22 side is arranged in such a manner as to be in direct contact with the heat-conducting paths 13 of the circuit board 2D, and is configured to be thermally connected to the heat-conducting member 40 on the case body 21 side via the heat-conducting paths 13.For example, the heat-conducting member 50 is formed such that the shape of an orthogonal projection of the heat-conducting member 50 onto the printed circuit board 11 is substantially the same as the shape of an orthogonal projection of the heat-conducting member 40 on the case body 21 side onto the printed circuit board 11. However, it should be noted that the heat-conducting member 50 may have any given shape, provided that such a shape allows the heat-conducting member 50 to be in direct contact with the heat-conducting paths 13.

[0053] In this embodiment, the heat-conducting member 40, which is in direct contact with the electronic component 16 and the case body 21 of the case 3, is thermally connected to the heat-conducting member 50 in direct contact with the cover 22 of the case 3 via the heat-conducting paths 13 of the circuit board 2D. Therefore, heat is transferred from the electronic component 16 to the case body 21 via the heat-conducting member 40 and is dissipated to the outside of the case 3, and is also transferred from the heat-conducting member 40 to the heat-conducting member 50 through the heat-conducting paths 13, is finally transferred to the cover 22, and is dissipated to the outside of the case 3. In other words, a heat dissipation path leading from the electronic component 16 to the outside of the case 3 is provided not only on the case body 21 side but also on the cover 22 side.This allows heat dissipation from both sides, i.e., from the housing body 21 and from the cover 22 of the housing 3. [First modification of the second embodiment]

[0054] An electronic control device according to a first modification of the second embodiment will then be described with reference to the Fig. 11 and Fig. 12 described. Fig. 11 is a perspective view of the electronic component of a circuit board and a peripheral structure around the electronic component in the electronic control device according to a first example of the first modification of the second embodiment. Fig. 12 is a perspective view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a second example of the first modification of the second embodiment.

[0055] An electronic control device 1E according to the first example of the first modification of the second embodiment shown in Fig. 11 differs from the second embodiment mainly in the following points. First, a heat-conducting member 40E on the case body 21 side is structurally different from the heat-conducting member of the second embodiment. Second, the structure of a heat-conducting member 50E on the cover 22 side differs from the structure of the heat-conducting member on the cover 22 side of the second embodiment, in accordance with the structure of the heat-conducting member 40E on the case body 21 side. Third, the arrangement of the heat-conducting paths 13E of a circuit board 2E differs from the arrangement of the heat-conducting paths of the second embodiment, in accordance with the structures of the heat-conducting member 40E on the case body 21 side and the heat-conducting member 50E on the cover 22 side.

[0056] Specifically, the heat-conducting member 40E is arranged on the side of the housing body 21 in such a manner that it is in contact with the upper surface 16b of the electronic component 16 and with all three of the four side surfaces 16c. In other words, the heat-conducting member 40E has the conductive upper surface part 41 in contact with the upper surface 16b of the electronic component 16 and three conductive side surface parts 42E in contact with all three side surfaces 16c of the electronic component 16. For example, three heat-conducting paths 13E (two of which are in Fig. 11) are arranged in such a manner that they are each in contact with three conductive side surface parts 42E of the heat-conducting element 40E. The heat-conducting element 50E on the cover 22 side is arranged in a position in which the heat-conducting element 50E is located on the second surface 11b of the printed circuit board 11, in such a manner as to avoid an area below the electronic component 16 and include the position of the arrangement of the heat-conducting paths 13E. The heat-conducting element 50E is formed such that, for example, the shape of an orthogonal projection of the heat-conducting element 50E onto the printed circuit board 11 is the same as the shape of an orthogonal projection of three conductive side surface parts 42E of the heat-conducting element 40E on the case body 21 side onto the printed circuit board 11.

[0057] An electronic control device 1F according to the second example of the first modification of the second embodiment shown in Fig. 12 differs from the second embodiment mainly in the following points. First, a heat-conducting member 40F on the case body 21 side differs in structure from the heat-conducting member on the case body 21 side of the second embodiment. Second, the structure of a heat-conducting member 50F on the cover 22 side differs from the structure of the heat-conducting member on the cover 22 side of the second embodiment, in accordance with the structure of the heat-conducting member 40F on the case body 21 side. Third, the arrangement of the heat-conducting paths 13F of a circuit board 2F differs from the arrangement of the heat-conducting paths of the second embodiment, in accordance with the structures of the heat-conducting member 40F on the case body 21 side and the heat-conducting member 50F on the cover 22 side.

[0058] Specifically, the heat-conducting element 40F is arranged on the side of the housing body 21 in such a manner that it is in contact with the upper surface 16b of the electronic component 16 and with the entire two adjacent side surfaces of the four side surfaces 16c. In other words, the heat-conducting element 40F has the conductive upper surface part 41 in contact with the upper surface 16b of the electronic component 16, and two conductive side surface parts 42F in contact with the entire two adjacent side surfaces 16c of the electronic component 16. Two heat-conducting paths 13F (one of which is in Fig. 12) are arranged in such a manner that they are each in contact with two conductive side surface parts 42F of the heat-conducting element 40F. The heat-conducting element 50F on the cover 22 side is arranged in a position in which the heat-conducting element 50F is located on the second surface 11b of the printed circuit board 11, in such a manner as to avoid an area below the electronic component 16 and to include the position of the arrangement of the heat-conducting paths 13F. The heat-conducting element 50F is formed such that, for example, the shape (L-shape) of an orthogonal projection of the heat-conducting element 50F onto the printed circuit board 11 is the same as the shape of an orthogonal projection of two conductive side surface parts 42F of the heat-conducting element 40F on the case body 21 side onto the printed circuit board 11.

[0059] On the circuit boards 2E and 2F in the first and second examples of the first modification of the second embodiment, wiring lines and chip components can be densely mounted in a region of the second surface 11b of the printed circuit board 11, which region is the back side of the part where the high-performance electronic component 16 is mounted. This case imposes restrictions on the arrangement of the heat-conducting members 50E and 50F on the cover 22 side. The heat-conducting members 50E and 50F on the cover 22 side each have a structure that copes with such an assumed case. The heat-conducting members 50E and 50F are thermally connected to the heat-conducting members 40E and 40F via the heat-conducting paths 13E and 13F of the circuit boards 2E and 2F, respectively, thereby transferring heat from the electronic component 16 to the cover 22.It is therefore not necessary to arrange the heat-conducting elements 50E and 50F in such a manner that they are in contact with the entire area of ​​the second surface 11b of the printed circuit board 11, the area being the back of the part on which the electronic component 16 is mounted.

[0060] In the first and second examples of the first modification, the heat-conducting members 40E and 40F, which are in direct contact with the electronic component 16, are thermally connected to the heat-conducting members 50E and 50F via the heat-conducting paths 13E and 13F of the circuit boards 2E and 2F, respectively, as in the case of the second embodiment. Therefore, heat is transferred from the electronic component 16 to the case body 21 via the heat-conducting members 40E and 40F and is dissipated to the outside of the case 3, and is also transferred from the heat-conducting members 40E and 40F to the heat-conducting members 50E and 50F via the heat-conducting paths 13E and 13F, and is finally transferred to the cover 22 and is dissipated to the outside of the case 3.In other words, a heat dissipation path leading from the electronic component 16 to the outside of the housing 3 is provided not only on the housing body 21 side but also on the cover 22 side. This enables heat dissipation from both sides, that is, from the housing body 21 and the cover 22 of the housing 3. [Second modification of the second embodiment]

[0061] An electronic control device according to a second modification of the second embodiment will then be described with reference to the Fig. 13 and Fig. 14 described. Fig. 13 is a cross-sectional view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a first example of the second modification of the second embodiment. Fig. 14 is a cross-sectional view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to a second example of the second modification of the second embodiment.

[0062] An electronic control device 1G according to the first example of the second modification of the second embodiment shown in Fig. 13 differs from the first example of the first modification of the second embodiment in that the arrangement and number of the heat-conducting paths 13G of a circuit board 2G are different from the arrangement and number of heat-conducting paths of the first example of the first modification of the second embodiment. Specifically, the heat-conducting paths 13G are not arranged sequentially on each of the three conductive side surface parts 42E of the heat-conducting member 40E on the case body 21 side, but are arranged as rows of two heat-conducting paths, each row being located on each of the three conductive side surface parts 42E spaced apart along the circumferential direction of the side surface 16c of the electronic component 16.

[0063] An electronic control device 1H according to the second example of the second embodiment shown in Fig. 14 differs from the first example of the second embodiment in that the arrangement and number of heat-conducting paths 13H of the circuit board 2G differ from the arrangement and number of heat-conducting paths of the second example of the second modification of the second embodiment. Specifically, the heat-conducting paths 13H are arranged as rows of four heat-conducting paths, each row being located on each of the three conductive side surface parts 42E of the heat-conducting member 40E on the case body 21 side, which are spaced apart along the circumferential direction of the side surface 16c of the electronic component 16.

[0064] In the first and second examples of the second modification of the second embodiment, as in the case of the first example of the first modification of the second embodiment, the heat-conducting members 40E in direct contact with the electronic component 16 are thermally connected to the heat-conducting members 50E via the heat-conducting paths 13G and 13H of the circuit boards 2G and 2H. Therefore, heat from the electronic component 16 is transferred to the case body 21 via the heat-conducting members 40E and is dissipated to the outside of the case 3, and is also transferred from the heat-conducting members 40E to the heat-conducting members 50E via the heat-conducting paths 13G and 13H, is finally transferred to the cover 22, and is dissipated to the outside of the case 3.In other words, a heat dissipation path leading from the electronic component 16 to the outside of the housing 3 is provided not only on the housing body 21 side but also on the cover 22 side. This enables heat dissipation from both sides, that is, from the housing body 21 and the cover 22 of the housing 3.

[0065] Furthermore, in the first and second examples of the second modification, the heat conducting paths 13G and 13H of the circuit boards 2G and 2H are arranged as rows of two heat conducting paths or four heat conducting paths (rows of multiple heat conducting paths) spaced apart along the side surfaces 16c of the electronic component 16, and are in contact with the heat conducting member 40 on the case body 21 side and the heat conducting member 50E on the cover 22 side. According to this configuration, heat transfer from the heat conducting member 40E on the case body 21 side to the heat conducting member 50E on the cover 22 side is efficient via the heat conducting paths 13G and 13H.As a result, the amount of heat transferred from the electronic component 16 to the heat-conducting member 50E on the cover 22 side via the heat-conducting paths 13G and 13H becomes larger than that in the first example and the second example of the first modification of the second embodiment. This improves the heat dissipation performance. [Third modification of the second embodiment]

[0066] An electronic control device according to a third modification of the second embodiment will then be described with reference to Fig. 15 to 17 described. Fig. 15 is a schematic diagram showing an arrangement relationship between the electronic component of a circuit board and heat conducting paths (through holes) in an electronic control device according to a first example of the third modification of the second embodiment. Fig. 16 is a schematic diagram showing an arrangement relationship between the electronic component of a circuit board and heat-conducting paths (through holes) in an electronic control device according to a second example of the third modification of the second embodiment. Fig. 17 is a contour diagram showing a heat flow rate in the circuit board in the electronic control device according to the first example of the third modification of the second embodiment.

[0067] The electronic control device according to the first example of the third modification of the second embodiment shown in Fig. 15 differs from the second embodiment in that the arrangement of the heat-conducting paths 13J of a circuit board 2J differs from the arrangement of the heat-conducting paths in the second embodiment. Specifically, similar to the heat-conducting paths 13 of the circuit board 2D according to the second embodiment, heat-conducting paths 13J of the circuit board 2J according to the first example of the third modification of the second embodiment are arranged in one-to-one correspondence with the central part of each of the four side surfaces 16c of the electronic component 16, but each of the heat-conducting paths 13J is located closer to the central part of each of the four side surfaces 16c of the electronic component 16 than each of the heat-conducting paths 13 according to the second embodiment.

[0068] The electronic control device according to the second example of the third modification of the second embodiment shown in Fig. 16 differs from the first example of the third modification of the second embodiment in that the arrangement of the heat-conducting paths 13K of a circuit board 2K differs from the arrangement of the heat-conducting paths of the first example of the third modification of the second embodiment.Specifically, the heat conducting paths 13K of the circuit board 2K according to the second example of the third modification of the second embodiment, wherein the heat conducting paths 13K are different in arrangement from the heat conducting paths 13J according to the first example of the third modification of the second embodiment, are arranged in one-to-one correspondence to each of two adjacent side surfaces of the four side surfaces 16c of the electronic component 16 and are each located closer to the central part of each of the two side surfaces 16c of the electronic component 16 in the same manner as the heat conducting paths 13J according to the example of the third modification.

[0069] In the electronic control device according to the first and second examples of the third modification of the second embodiment, the heat-conducting paths 13J and 13K of the circuit boards 2J and 2K are arranged at positions where the heat-conducting paths 13J and 13K correspond to the central part of at least one of the four side surfaces 16c of the electronic component 16. As can be seen from the Fig. As can be seen from the thermal fluid analysis result shown in Fig. 17, heat is transferred radially from the IC chip 32 in the center of the electronic component 16. For this reason, heat from the IC chip 32 is transferred most intensively to the central part of each side surface 16c of the electronic component 16. Therefore, through the heat-conducting paths 13J and 13K of the circuit boards 2J and 2K, heat can be efficiently transferred from the heat-conducting member (not shown) on the case body 21 side to the heat-conducting member (not shown) on the cover 22 side.

[0070] In the first and second examples of the third modification of the second embodiment, the electronic component 16 has the IC chip 32 serving as the heat source at its center, and a plurality of the heat conductive paths 13J and 13K of the circuit boards 2J and 2K are spaced at the positions equidistant from the IC chip 32 serving as the heat source of the electronic component 16.

[0071] According to this configuration, due to the radial transfer of heat from the IC chip 32 as the heat source, substantially the same amount of heat is transferred to the plurality of heat conducting paths 13J and 13K located at the positions equidistant from the IC chip 32. This enables heat dissipation without bias.

[0072] In the first and second examples of the third modification of the second embodiment, it is preferable that the heat conducting paths 13J and 13K of the circuit boards 2J and 2K be arranged at positions where the heat conducting paths 13J and 13K are closest to the outer peripheral surface 16c of the electronic component 16. According to this configuration, heat radially transferred from the electronic component 16 can be efficiently conducted to the heat conducting paths 13J and 13K.

[0073] As described above, according to the second embodiment and its modifications, by disposing each of the heat-conducting members 40, 40E, and 40F (first heat-conducting members) in such a manner that the heat-conducting member is brought into contact with the upper surface 16b of the electronic component 16 and with a part of the outer peripheral surface 16c, the heat dissipation performance is maintained, and by disposing each of the heat-conducting members 40, 40E, and 40F (first heat-conducting members) in a position where the heat-conducting member avoids a space above the high-speed signal line 12, an increase in the capacitance between the high-speed signal line 12 and the housing 3 caused by the arrangement of each of the heat-conducting members 40, 40E, and 40F (first heat-conducting members) can be avoided in the same manner as in the first embodiment.This ensures the quality of a high-frequency signal and suppresses radiation interference while maintaining heat dissipation capability.

[0074] In this embodiment and its modifications, the circuit boards 2D, 2E, 2F, 2G, 2H, 2J and 2K have the heat-conducting paths 13, 13E, 13F, 13G, 13H, 13J and 13K provided on the printed circuit board 11 (printed circuit board), and the heat-conducting paths 13, 13E, 13F, 13G, 13H, 13J and 13K of the circuit boards 2D, 2E, 2F, 2G, 2H, 2J and 2K are provided at the positions where the heat-conducting paths 13, 13E, 13F, 13G, 13H, 13J and 13K are connected to the heat-conducting elements 40, 40E and 40F (first heat-conducting elements) can be thermally connected.

[0075] According to this configuration, heat of the electronic component 16 is transferred from the heat-conducting elements 40, 40E, and 40F (first heat-conducting elements) to the housing 3, and is also transferred from the heat-conducting elements 40, 40E, and 40F (first heat-conducting elements) to the printed circuit boards 11 (circuit boards) of the circuit boards 2D, 2E, 2F, 2G, 2H, 2J, and 2K via the heat-conducting paths 13, 13E, 13F, 13G, 13H, 13J, and 13K of the circuit boards 2D, 2E, 2F, 2G, 2H, 2J, and 2K. This configuration therefore improves the heat dissipation performance more than the first embodiment and its modification.

[0076] The electronic control device according to this embodiment and its modifications further includes the heat-conducting elements 50, 50E, and 50F (second heat-conducting elements), each of which is in direct contact with the second surface 11b located on the back side of the first surface 11a of the two surfaces of the printed circuit board 11 (circuit board) and with the housing 3. The heat-conducting elements 50, 50E, and 50F (second heat-conducting elements) are thermally connected to the heat-conducting elements 40, 40E, and 40F (first heat-conducting elements) via the heat-conducting paths 13, 13E, 13F, 13G, 13H, 13J, and 13K of the circuit boards 2D, 2E, 2F, 2G, 2H, 2J, and 2K.

[0077] According to this configuration, heat of the electronic component 16 is transferred to one side (case body 21) of the case 3 via the heat-conducting members 40, 40E, and 40F (first heat-conducting members) and is discharged to the outside, and is also transferred to the heat-conducting members 50, 50E, and 50F (second heat-conducting members) via the heat-conducting paths 13, 13E, 13F, 13G, 13H, 13J, and 13K, is finally transferred to the other side (cover 22) of the case 3 and is discharged to the outside. In other words, two types of heat dissipation paths leading from the electronic component 16 to the outside of the housing 3 are provided, namely, a heat dissipation path on one side of the housing 3 and a heat dissipation path on the other side of the housing 3. Therefore, the heat dissipation performance can be improved.

[0078] In the second embodiment, the heat-conducting member 40 (first heat-conducting member) is arranged in such a manner as to contact a part of each of the four side surfaces 16c of the electronic component 16 in the position in which the heat-conducting member 40 avoids a space above the high-speed signal line 12, and the heat-conducting paths 13 of the circuit board 2D are arranged in one-to-one correspondence with each of the four side surfaces 16c of the electronic component 16.

[0079] According to this configuration, heat of the electronic component 16 is transferred to the heat-conducting paths 13 arranged in one-to-one correspondence with the four side surfaces 16c of the electronic component 16 via the heat-conducting member 40 (first heat-conducting member) in contact with the four side surfaces 16c of the electronic component 16. Therefore, heat transfer from the electronic component 16 to the heat-conducting paths 13 can be performed efficiently, and thereby the heat dissipation performance is improved. [Third Embodiment]

[0080] An electronic control device according to a third embodiment of the present invention will then be described with reference to Fig. 18 described. Fig. 18 is a schematic cross-sectional view of the electronic component of a circuit board and a peripheral structure around the electronic component in an electronic control device according to the third embodiment of the present invention.

[0081] An electronic control device 1L according to the third embodiment shown in Fig. 18 differs from the second embodiment in that the electronic control device 1L further includes a thermally conductive member 60 disposed between the first surface 11a of the printed circuit board 11 and the lower surface 16a of the electronic component 16. Specifically, the thermally conductive member 60 is an underfill that reinforces a solder joint between solder balls 33 on the lower surface 16a of the electronic component 16 and a wiring pattern on the first surface 11a of the printed circuit board 11. The underfill 60, which improves the durability of the solder joint, is made of, for example, an epoxy resin and functions as a thermally conductive member.Other structural elements of the electronic control device 1L according to the third embodiment are the same as those of the electronic control device 1D according to the second embodiment and are therefore omitted from further description.

[0082] In this embodiment, the underfill 60 disposed between the printed circuit board 11 and the electronic component 16 in the circuit board 2L, in addition to the heat-conducting member 40 on the case body 21 side and the heat-conducting member 50 on the cover 22 side, functions as a heat-conducting member for transferring heat of the electronic component 16. This makes it possible to increase a heat transfer amount from the electronic component 16 to the printed circuit board 11 and simultaneously improve the reliability of the solder connection between the electronic component 16 and the printed circuit board 11. Therefore, an improvement in the solder life of the solder joint and an improvement in heat dissipation performance can be achieved simultaneously.

[0083] According to the third embodiment, by disposing the heat-conducting member 40 (first heat-conducting member) in such a manner that the heat-conducting member 40 is brought into contact with the upper surface 16b of the electronic component 16 and with a part of the outer peripheral surface 16c, the heat dissipation performance is maintained, and by disposing the heat-conducting member 40 (first heat-conducting member) in a position where the heat-conducting member 40 avoids a space above the high-speed signal line (not shown), an increase in the capacitance between the high-speed signal line and the housing 3 caused by the arrangement of the heat-conducting member 40 (first heat-conducting member) can be avoided in the same way as in the first embodiment.This ensures the quality of a high-frequency signal and suppresses radiation interference by maintaining heat dissipation capability.

[0084] The electronic control device 1L according to the third embodiment further includes the heat-conducting member 60 arranged between the first surface 11a of the printed circuit board 11 (circuit board) and the lower surface 16a of the electronic component 16.

[0085] According to this configuration, heat from the electronic component 16 can be transferred to the housing 3 via the heat-conducting member 40 and can also be transferred to the printed circuit board 11 (PCB) via the heat-conducting member 60. Therefore, the heat dissipation performance can be improved.

[0086] In this embodiment, the thermally conductive element 60 (third thermally conductive element) is the underfill that reinforces the solder connection on the bottom surface 16a of the electronic component 16.

[0087] According to this configuration, the heat-conducting member 60 enables improvement of both the solder life and the heat dissipation performance. [Fourth Embodiment]

[0088] An electronic control device according to a fourth embodiment of the present invention will then be described with reference to Fig. 19 described. Fig. 19 is a schematic perspective view of an appearance of the electronic control device according to the fourth embodiment of the present invention. In Fig. 19 are components identified by the same reference numerals as in the Fig. 1 to 18 are the same as those shown in the Fig. 1 to 18 and are therefore not described in detail in the further description.

[0089] An electronic control device 1M according to the fourth embodiment shown in Fig. 19 differs from the first embodiment in that cooling fans 70 are mounted on the case body 21 of the case 3. The electronic control device 1M is a forced air cooling type device that supplies the cooling air generated by the cooling fans 70 to a heat dissipation fin 25 of the case body 21.

[0090] In this embodiment, cooling air is driven by the Fig. 19, heat is generated by the cooling fan 70 shown in Fig. 2 is transferred to the case body 21 of the case 3 via the heat-conducting member 40. This causes the temperature of the case 3 to decrease to increase a temperature difference between the case 3 and the electronic component 16, which accelerates heat transfer from the electronic component 16 to the case 3. Therefore, the heat dissipation performance of the electronic control device 1M is further improved.

[0091] As described above, the electronic control device 1M according to this embodiment further includes the cooling fans 70 that supply cooling air to the outer surface of the housing 3. According to this configuration, heat transfer from the electronic component 16 to the housing 3 is accelerated, and therefore, the heat dissipation performance of the electronic control device 1M is further improved. [Fifth Embodiment]

[0092] An electronic control device according to a fifth embodiment of the present invention will be described with reference to Fig. 20 described. Fig. 20 is a schematic perspective view of an appearance of the electronic control device according to the fifth embodiment of the present invention. In Fig. 20, the components are identified by the same reference numerals as in the Fig. 1 to 19 are the same as those shown in the Fig. 1 to 19 and are therefore not described in detail in the further description.

[0093] An electronic control device 1N according to the fifth embodiment shown in Fig. 20 differs from the first embodiment in that the electronic control device 1N is provided with a water cooling system 80 that supplies cooling water to the housing 3 to cool the housing 3. Specifically, the water cooling system 80 includes a supply line 81 that supplies cooling water to the housing 3 and a discharge line 82 through which the cooling water discharged from the housing 3 flows. The electronic control device 1 is a forced water cooling type device that cools the housing 3 by cooling water supplied through the supply line 81 and then discharges cooling water through the discharge line 82.

[0094] In this embodiment, the absorbed by the Fig. 20 shown water cooling system 80 supplied cooling water heat, which is taken up by the Fig.2 is transferred to the housing body 21 of the housing 3 via the heat-conducting element 40. This causes the temperature of the housing 3 to decrease to increase a temperature difference between the housing 3 and the electronic component 16, which accelerates heat transfer from the electronic component 16 to the housing 3. This further improves the heat dissipation performance of the electronic component 16 of the electronic control device 1M.

[0095] As described above, the electronic control device 1N according to this embodiment further includes the water cooling system 80 that supplies cooling water to the housing 3 to cool the housing 3. According to this configuration, heat transfer from the electronic component 16 to the housing 3 is accelerated, and therefore, the heat dissipation performance of the electronic control device 1M is further improved. [Other embodiments]

[0096] It should be noted that the present invention is not limited to the above embodiments, but includes various modifications. For example, the above embodiments have been described in detail in order to provide an understandable description of the present invention, and are not necessarily limited to an embodiment including all of the components described above. Some of the components of one embodiment may be replaced by components of another embodiment, and a component of another embodiment may be added to a component of an embodiment. Some of the components of this embodiment may be deleted, added to, or replaced by other components.

[0097] For example, the above embodiments were described as examples in which the electronic control device 1 is configured as an electronic control device integrated into a vehicle to control or assist the driving of the vehicle. However, the electronic control device as an electronic control device that performs high-speed communication can also be integrated into systems or equipment other than vehicles. For example, the electronic control device can be used as an electronic control device integrated into an unmanned aerial vehicle (drone) or the like.

[0098] In the above embodiments, examples of the configuration in which the electronic component 16 capable of high-speed operation has the semiconductor package of the BGA structure have been described. The electronic component for high-speed processing may be configured to have a surface-mount semiconductor package such as a quad flat package (QFP) structure, a quad flat non-leaded package (QFN), or a small outline package (SOP) structure. In addition, the electronic component capable of high-speed operation may also be configured to have a semiconductor package for panel mounting such as a pin grid array (PGA) structure. List of reference symbols 1, 1D, 1E, 1F, 1G, 1H, 1L, 1M, 1N electronic control device 2, 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2J, 2K, 2L circuit board 3 housings 11 printed circuit board (PCB) 11a first surface 11b second surface 12, 12A, 12B, 12C high-speed signal line 13, 13E, 13F, 13G, 13H, 13J, 13K thermal conduction path 16 electronic components 16a lower surface 16b upper surface 16c outer peripheral surface (lateral surface) 32 IC chip (chip) 40, 40A, 40B, 40C, 40E, 40F heat-conducting element (first heat-conducting element) 50, 50E, 50F heat-conducting element (second heat-conducting element) 60 Underfill (third heat-conducting element) 70 cooling fans 80 water cooling system QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2011-023593 A

[0005]

Claims

[1] Electronic control device comprising: a circuit board including a printed circuit board including a wiring structure with a high-speed signal line, and an electronic component mounted on a first surface of both surfaces of the printed circuit board, the electronic component being electrically connected to the high-speed signal line; a housing that houses the circuit board; and a first heat-conducting element in direct contact with the electronic component and with the housing, wherein the electronic component has a lower surface facing the first surface of the circuit board, an upper surface opposite the lower surface, and an outer peripheral surface connected to an outer edge of the lower surface and to an outer edge of the upper surface, and wherein the first heat-conducting member is arranged in such a manner that it extends from the upper surface of the electronic component to the housing in a position in which the first heat-conducting member avoids a space above the high-speed signal line, and extends from the first surface of the circuit board to the housing while being in contact with a part of the outer peripheral surface of the electronic component. [2] Electronic control device according to claim 1, wherein the electronic component is formed into a rectangular shape in a view from a side where the upper surface is located and has four side surfaces as the outer peripheral surface, and wherein the first heat-conducting member is arranged in such a manner that it extends from the first surface of the circuit board to the housing while being in contact with a part of each of the four side surfaces of the electronic component in a position in which the first heat-conducting member avoids a space above the high-speed signal line. [3] Electronic control device according to claim 1, wherein the electronic component comprises a chip serving as an integrated heat source, and wherein the first thermally conductive element is in contact with the upper surface of the electronic component in such a way that it includes an entire area of ​​an orthogonal projection of the chip onto the upper surface of the electronic component. [4] Electronic control device according to claim 1, wherein the circuit board includes a heat-conducting path provided on the circuit board, and wherein the thermally conductive path of the circuit board is arranged at a position where the thermally conductive path can be thermally connected to the first thermally conductive element. [5] The electronic control device according to claim 4, further comprising a second thermally conductive member in direct contact with a second surface of both surfaces of the circuit board and with the housing, the second surface being on the back side of the first surface, the second thermally conductive member being thermally connected to the first thermally conductive member via the thermally conductive path of the circuit board. [6] Electronic control device according to claim 4, wherein the electronic component is formed into a rectangular shape in a view from a side where the upper surface is located and has four side surfaces as the outer peripheral surface, and wherein the heat-conducting path of the circuit board is arranged at a position where the heat-conducting path corresponds to a central part of at least one of the four side surfaces of the electronic component. [7] Electronic control device according to claim 4, wherein the electronic component is formed into a rectangular shape in a view from a side where the upper surface is located and has four side surfaces as an outer peripheral surface, wherein the first heat-conducting element is arranged in such a way that it is in contact with a part of each of the four side surfaces of the electronic component in a position in which the first heat-conducting element avoids a space above the high-speed signal line, and wherein the thermal conduction path of the circuit board is arranged in one-to-one correspondence to each side surface of the four side surfaces of the electronic component. [8] The electronic control device according to claim 4, wherein the heat-conducting path of the circuit board is arranged at a position closest to the outer peripheral surface of the electronic component. [9] Electronic control device according to claim 4, wherein the electronic component has a heat source at a center of the electronic component, and wherein several of the heat-conducting paths of the circuit board are spaced at positions equidistant from the heat source of the electronic component. [10] The electronic control device according to claim 4, wherein the heat conducting paths of the circuit board are a plurality of rows of heat conducting paths arranged in a direction along the outer peripheral surface of the electronic component. [11] The electronic control device according to claim 1, further comprising a third heat-conducting member disposed between the first surface of the circuit board and the lower surface of the electronic component. [12] The electronic control device according to claim 11, wherein the third thermally conductive element is an underfill reinforcing a solder joint on the lower surface of the electronic component. [13] The electronic control device according to claim 1, further comprising a cooling fan that supplies cooling air to an outer surface of the housing. [14] The electronic control device according to claim 1, further comprising a water cooling system that supplies cooling water to the housing to cool the housing.

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