Vehicle circuit board

Abstract

The invention provides a vehicle circuit board capable of improving heat dissipation performance. This circuit board (10) is mounted on a vehicle, and is provided with: a substrate (20); a first electronic component (30) mounted on the substrate (20) and having a heat source terminal (33); a second electronic component (40) mounted on the substrate (20) and having at least one of a communication function, a storage function, and an information processing function; and a heat transfer path (50) provided on the substrate (20) and connecting the heat source terminal (33) and the idle terminal (43) of the second electronic component (40).

Description

Technical Field

[0001] The present invention relates to a circuit board for a vehicle. Background Art

[0002] In the past, various methods are known as heat countermeasures for circuit substrates mounted on vehicles. For example, the following patent document 1 describes a method in which a pin portion of a heat generating component mounted on a circuit substrate and a fixing pin of a connector mounted on the circuit substrate are connected via printed wiring. According to this method, the heat of the heat generating component is conducted through the printed wiring and released to the fixing pin of the connector. By using the fixing pin as part of the heat dissipation structure, the heat dissipation can be improved without using a dedicated component for heat countermeasures. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-41485 Summary of the invention Problems to be solved by the invention

[0004] In the above-mentioned structure, the heat dissipation point of the heat generating component is limited to the fixing pins. It is desirable to increase the heat dissipation point of the heat generating component so as to improve the heat dissipation of the vehicle circuit board.

[0005] The present invention has been made based on the above circumstances, and an object of the present invention is to provide a circuit board for a vehicle that can improve heat dissipation. Solutions to Solve Problems

[0006] The vehicle circuit substrate of the present invention is a circuit substrate mounted on a vehicle, comprising: a substrate; a first electronic component mounted on the substrate and having a heat source terminal; a second electronic component mounted on the substrate and having at least one of a communication function, a storage function and an information processing function; and a heat transfer path arranged on the substrate and connecting the heat source terminal and an idle terminal of the second electronic component. Effects of the Invention

[0007] According to the present invention, it is possible to provide a vehicle circuit board capable of improving heat dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a plan view showing a vehicle circuit board according to the present embodiment. Figure 2 is a cross-sectional view showing a circuit substrate for a vehicle, which is equivalent to Figure 1 Cross-sectional view of the section at position AA. Figure 3 is a cross-sectional view showing a circuit substrate for a vehicle, which is equivalent to Figure 1Cross-sectional view of the section at the BB position. Figure 4 is a cross-sectional view showing a circuit substrate for a vehicle, which is equivalent to Figure 1 Cross-sectional view of the section at the CC position. DETAILED DESCRIPTION

[0009] [Description of Embodiments of the Invention] First, embodiments of the present invention will be described by way of examples.

[0010] (1) The vehicle circuit substrate of the present invention is a circuit substrate mounted on a vehicle, comprising: a substrate; a first electronic component mounted on the substrate and having a heat source terminal; a second electronic component mounted on the substrate and having at least one of a communication function, a storage function, and an information processing function; and a heat transfer path provided on the substrate and connecting the heat source terminal and the idle terminal of the second electronic component. According to such a structure, the heat of the first electronic component is released to the idle terminal of the second electronic component via the heat transfer path. Since the idle terminal of the second electronic component can be used as a heat dissipation structure, the heat dissipation can be improved. (2) The first electronic component and the second electronic component may be both arranged on the first surface of one of the front and back surfaces of the substrate, and the heat transfer path extends from the heat source terminal to the idle terminal of the second electronic component on the first surface. According to such a structure, the heat of the first electronic component is released to the idle terminal of the second electronic component via the heat transfer path on the first surface. Since the idle terminal of the second electronic component can be used as a heat dissipation structure, the heat dissipation can be improved. (3) Alternatively, the substrate may be a laminated substrate having a plurality of insulating layers laminated thereon, the first electronic component and the second electronic component may be disposed on a first surface, which is one of the front and back surfaces of the laminated substrate, and the heat transfer path may extend from the heat source terminal through the interior of the laminated substrate to the idle terminal of the second electronic component. According to such a structure, the heat of the first electronic component is released to the idle terminal of the second electronic component through the interior of the laminated substrate. Even in the case where the heat transfer path cannot be disposed on the first surface, the idle terminal of the second electronic component may be utilized as a heat dissipation structure, thereby improving heat dissipation. (4) Alternatively, the first electronic component may be disposed on the first surface of one of the front and back surfaces of the substrate, and the second electronic component may be disposed on the second surface of the other of the front and back surfaces of the substrate, and the heat transfer path may penetrate the substrate in the thickness direction and extend from the heat source terminal to the idle terminal of the second electronic component. According to such a structure, the heat of the first electronic component penetrates the substrate in the thickness direction and is released to the idle terminal of the second electronic component. The idle terminal of the second electronic component disposed on the second surface can be used as a heat dissipation structure, so that the heat dissipation can be improved. (5) The idle terminals may be input / output terminals having a communication function. According to such a configuration, since the input / output terminals can be used as a heat dissipation structure, heat dissipation can be improved. (6) The idle terminals may be terminals for information storage. According to such a structure, since the terminals for information storage can be used as a heat dissipation structure, the heat dissipation performance can be further improved. (7) The maximum value of the current input to the first electronic component may be greater than the maximum value of the current input to the second electronic component. According to this configuration, the first electronic component is a high heat generating component, and the second electronic component is a lower heat generating component than the first electronic component. (8) The first electronic component may be a power device. According to such a configuration, heat of the power device can be released to the idle terminals of the second electronic component.

[0011] [Details of Embodiments of the Invention] Specific examples of the vehicle circuit board of the present invention are described below with reference to the drawings. The present invention is not limited to these examples, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0012] The vehicle circuit board (hereinafter referred to as the circuit board 10 ) of the present embodiment is mounted on a vehicle such as an electric vehicle or a hybrid vehicle. The circuit board 10 is provided in an ECU (Electronic Control Unit).

[0013] like Figure 1 As shown in FIG. 1 , the circuit board 10 includes a substrate 20, a first electronic component 30, a second electronic component 40, and a heat transfer path 50. Figure 2 As shown, the substrate 20 is a laminated substrate having two insulating layers 21 laminated thereon. A wiring pattern 24 is formed on the substrate 20. The wiring pattern 24 is formed on a first surface 22 on one of the front and back surfaces of the substrate 20, a second surface 23 on the other of the front and back surfaces of the substrate 20, and inside the substrate 20. The wiring pattern 24 includes a conductive material such as copper foil. The wiring pattern 24 is appropriately omitted in the drawings.

[0014] The first electronic component 30 and the second electronic component 40 are mounted on the substrate 20. The first electronic component 30 and the second electronic component 40 generate heat when energized. The heat generated by the first electronic component 30 is greater than the heat generated by the second electronic component 40. The first electronic component 30 is a high heat generating component, and the second electronic component 40 is a low heat generating component. The maximum value of the current input to the first electronic component 30 is greater than the maximum value of the current input to the second electronic component 40.

[0015] The first electronic component 30 is mounted on the first surface 22. The first electronic component 30 is a power device. The power output from the first electronic component 30 and the heat generated by the first electronic component 30 are relatively large, and the heat resistance temperature is also relatively high.

[0016] like Figure 2 As shown, the first electronic component 30 has a main body 31, a terminal 32 and a heat source terminal 33. The main body 31 has a box-shaped package. The material of the package is plastic, metal, ceramic, etc. A plurality of terminals 32 protrude from the bottom and side surfaces of the main body 31. The terminal 32 is a pin, an electrode pad, etc. The heat source terminal 33 is a metal component exposed on the outer surface of the main body 31. The heat source terminal 33 is a heat dissipation pad, a GND terminal, a heat sink, etc. The heat generated by the heat source terminal 33 is greater than the heat generated by the terminal 32. The volume of the portion of the heat source terminal 33 exposed from the main body 31 is greater than the volume of the portion of each terminal 32 exposed from the main body 31.

[0017] The package type of the first electronic component 30 may also be a TO series (Transistor Outline), SOT series (Small Outline Transistor), QFP series (Quad Flat Package), QFN series (Quad Flat Non-leaded Package), BGA (Ball Grid Array), etc. The first electronic component 30 may also be configured as a SoC (System on a Chip). The first electronic component 30 may also be an LDO (Low Drop Output) linear regulator.

[0018] The substrate 20 is provided with a plurality of second electronic components 40. The second electronic component 40 includes a first surface component 40F mounted on the first surface 22 and a second surface component 40S mounted on the second surface 23. The second electronic component 40 has at least one of a communication function, a storage function, and an information processing function. The second electronic component 40 performs data communication with the outside, or stores information, or processes various data. The second electronic component 40 can also be a microcontroller, a memory, etc. The heat generation of the second electronic component 40 is relatively small.

[0019] The second electronic component 40 has a main body 41, a terminal 42 and an idle terminal 43. The main body 41 has a box-shaped package. The material of the package can also be plastic, metal, ceramic, etc. The terminal 42 protrudes from the bottom and side of the main body 41. The terminal 42 can also be a pin, an electrode pad, etc.

[0020] The idle terminal 43 is any one of the terminals 42 of the second electronic component 40. Which terminal of the terminals 42 of the second electronic component 40 is set as the idle terminal 43 can be freely set. The idle terminal 43 of the second electronic component 40 does not exchange information or power with the outside. The idle terminal 43 of the second electronic component 40 is not connected to the wiring pattern 24. Even if heat flows through the idle terminal 43 of the second electronic component 40, it will not affect the function of the second electronic component 40. The idle terminal 43 of the second electronic component 40 can also be a terminal that is only provided for the establishment of a package. The idle terminal 43 of the second electronic component 40 can also be provided to expand the function of the second electronic component 40 in the future. For example, the idle terminal 43 can also be an auxiliary terminal for common mode (noise suppression) control. For example, the idle terminal 43 can be a terminal for input and output, or a terminal for information storage.

[0021] The package type of the second electronic component 40 can also be SO series such as SOP (Small Outline Package), SON series (Small Outline Non-leaded Package), QFP series (Quad Flat Package), QFN series (Quad Flat Non-leaded Package), BGA (Ball Grid Array), etc.

[0022] The heat transfer path 50 is provided on the substrate 20. The heat transfer path 50 connects the heat source terminal 33 of the first electronic component 30 and the idle terminal 43 of the second electronic component 40. The material of the heat transfer path 50 is a heat transfer material with high thermal conductivity or the like. The heat transfer path 50, like the wiring pattern 24, can also be formed by a conductive material such as copper foil. The heat transfer path 50 and the wiring pattern 24 are separated and do not intersect. The width dimension of the heat transfer path 50 (the dimension orthogonal to the extension direction) is greater than 0.5 mm. In the case where the width dimension of the heat transfer path 50 is too small, the heat dissipation effect will be reduced. However, if the width dimension of the heat transfer path 50 is greater than 0.5 mm, a sufficient heat dissipation effect can be obtained.

[0023] like Figure 2 As shown, the heat transfer path 50 has a first heat transfer path 50F extending from the heat source terminal 33 of the first electronic component 30 along the first surface 22 to the first surface component 40F. The first heat transfer path 50F extends from the first soldering pad 51 to the second soldering pad 52. The heat source terminal 33 of the first electronic component 30 is soldered to the first soldering pad 51. The idle terminal 43 of the second electronic component 40 is soldered to the second soldering pad 52. The first heat transfer path 50F is in close contact with the first surface 22. Figure 1As shown, the first heat transfer path 50F has one first pad 51 and a plurality of second pads 52. The first heat transfer path 50F branches from the first pad 51 toward each second pad 52. Each second pad 52 is provided at the position of the idle terminal 43 of each second electronic component 40.

[0024] like Figure 3 As shown, the heat transfer path 50 has a second heat transfer path 50S extending from the heat source terminal 33 of the first electronic component 30 through the inside of the substrate 20 to the first surface component 40F. The second heat transfer path 50S has a passage 53 and an inner layer 54. The second heat transfer path 50S extends from the first pad 51 along the first surface 22. The passage 53 penetrates the insulating layer 21 in the thickness direction from the first surface 22 to the inner layer 54. The passage 53 connects the second heat transfer path 50S of the first surface 22 and the inner layer 54. The inner layer 54 is arranged between the stacked insulating layers 21.

[0025] like Figure 4 As shown, the heat transfer path 50 has a third heat transfer path 50T extending from the heat source terminal 33 of the first electronic component 30 to the second surface component 40S. The third heat transfer path 50T has a passage 55. The third heat transfer path 50T extends from the first pad 51 along the first surface 22. The passage 55 penetrates the substrate 20 in the thickness direction from the first surface 22 to the second surface 23. The passage 55 connects the third heat transfer path 50T of the first surface 22 and the third heat transfer path 50T of the second surface 23. The third heat transfer path 50T extends from the passage 55 along the second surface 23 to the second pad 52.

[0026] Next, the function and effect of the embodiment constructed as described above are described. The circuit substrate 10 is mounted on a vehicle. The circuit substrate 10 includes a substrate 20, a first electronic component 30, a second electronic component 40, and a heat transfer path 50. The first electronic component 30 is mounted on the substrate 20 and has a heat source terminal 33. The second electronic component 40 is mounted on the substrate 20 and has at least one of a communication function, a storage function, and an information processing function. The heat transfer path 50 is provided on the substrate 20, connecting the heat source terminal 33 and the idle terminal 43 of the second electronic component 40. According to this structure, the heat of the first electronic component 30 is released to the idle terminal 43 of the second electronic component 40 via the heat transfer path 50. Since the idle terminal 43 of the second electronic component 40 can be used as a heat dissipation structure, the heat dissipation can be improved.

[0027] A plurality of second electronic components 40 are provided around the first electronic component 30. According to this structure, by providing a plurality of second electronic components 40, a plurality of heat dissipation points can be ensured, and the temperature of the first electronic component 30 can be effectively reduced. The number of second electronic components 40 configured is particularly large compared with the number of fixing pins or unused terminals of the connector even in one ECU. Therefore, as a heat dissipation point for the heat of the first electronic component 30, it is easy to ensure idle terminals 43 of a plurality of second electronic components 40, so that the heat dissipation can be improved. In addition, as a heat dissipation structure, gel or the like does not need to be used, and the use of high-heat generating components does not need to be controlled for the heat dissipation of the circuit substrate 10, so that the circuit substrate 10 can be made low-cost and miniaturized.

[0028] The first electronic component 30 and the second electronic component 40 are both arranged on the first surface 22 of the substrate 20. The first heat transfer path 50F extends from the heat source terminal 33 to the idle terminal 43 of the second electronic component 40 on the first surface 22. According to this structure, the heat of the first electronic component 30 is released to the idle terminal 43 of the second electronic component 40 via the heat transfer path 50 on the first surface 22. The idle terminal 43 of the second electronic component 40 can be used as a heat dissipation structure, so the heat dissipation can be improved.

[0029] The substrate 20 is a laminated substrate on which two insulating layers 21 are laminated. The first electronic component 30 and the second electronic component 40 are both arranged on the first surface 22 of the substrate 20. The second heat transfer path 50S extends from the heat source terminal 33 through the inside of the substrate 20 to the idle terminal 43 of the second electronic component 40. According to this structure, the heat of the first electronic component 30 is released to the idle terminal 43 of the second electronic component 40 through the inside of the substrate 20. Even if the first heat transfer path 50F cannot be arranged on the first surface 22, the idle terminal 43 of the second electronic component 40 can be used as a heat dissipation structure, so the heat dissipation can be improved.

[0030] The first electronic component 30 is arranged on the first surface 22 of the substrate 20. The second electronic component 40 is arranged on the second surface 23 of the substrate 20. The third heat transfer path 50T penetrates the substrate 20 in the thickness direction and extends from the heat source terminal 33 to the idle terminal 43 of the second electronic component 40. According to such a structure, the heat of the first electronic component 30 penetrates the substrate 20 in the thickness direction and is released to the idle terminal 43 of the second electronic component 40. Since the idle terminal 43 of the second electronic component 40 arranged on the second surface 23 can be used as a heat dissipation structure, the heat dissipation can be improved.

[0031] The idle terminals 43 are the input / output terminals 42 having a communication function. According to this structure, the input / output terminals 42 can be used as a heat dissipation structure, so that the heat dissipation performance can be improved.

[0032] The idle terminals 43 are the information storage terminals 42. According to this structure, the information storage terminals 42 can be used as a heat dissipation structure, so the heat dissipation performance can be further improved.

[0033] The maximum value of the current input to the first electronic component 30 is greater than the maximum value of the current input to the second electronic component 40. According to this structure, the first electronic component 30 is a high heat generating component, and the second electronic component 40 is a low heat generating component compared to the first electronic component 30.

[0034] The first electronic component 30 is a power-related device. According to this structure, the heat of the power-related device can be released to the idle terminal 43 of the second electronic component 40.

[0035] [Other embodiments of the present invention] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. In the above embodiment, the substrate 20 is a multilayer substrate including two insulating layers 21 , but the substrate may be a multilayer substrate including only one insulating layer or three or more insulating layers. In the above embodiment, the heat transfer path 50 includes the first heat transfer path 50F, the second heat transfer path 50S, and the third heat transfer path 50T. However, the heat transfer path may include only one of the first heat transfer path, the second heat transfer path, and the third heat transfer path. In the above-mentioned embodiment, the number and arrangement of the first electronic components 30 and the second electronic components 40 are exemplified, but these may be changed. Description of Reference Numerals

[0036] 10: Circuit board (circuit board for vehicles) 20: Substrate 21: Insulation layer 22: Surface 1 23: Surface 2 24: Wiring pattern 30: No. 1 electronic components 31: Main body 32: Terminal 33: Heat source terminal 40: Second electronic component 40F: 1st surface part 40S: 2nd surface part 41: Main body 42: Terminal 43: Idle terminal 50: Heat transfer path 50F: 1st heat transfer path 50S: 2nd heat transfer path 50T: 3rd heat transfer path 51: 1st pad 52: Second pad 53: Passage 54: Inner layer 55: Passage

Claims

1. A circuit board for a vehicle, which is a circuit board mounted on a vehicle, comprising: substrate; a first electronic component mounted on the substrate and having a heat source terminal; a second electronic component mounted on the substrate and having at least one of a communication function, a storage function and an information processing function; and The heat transfer path is provided on the substrate and connects the heat source terminal and the idle terminal of the second electronic component.

2. The vehicle circuit board according to claim 1, wherein: The first electronic component and the second electronic component are both arranged on a first surface, one of the front and back surfaces of the substrate. The heat transfer path extends on the first surface from the heat source terminal to an idle terminal of the second electronic component.

3. The vehicle circuit board according to claim 1 or claim 2, wherein: The substrate is a laminated substrate having a plurality of insulating layers laminated thereon, The first electronic component and the second electronic component are both arranged on a first surface, one of the front and back surfaces of the laminate substrate. The heat transfer path extends from the heat source terminal through the interior of the laminate substrate to an idle terminal of the second electronic component.

4. The vehicle circuit board according to claim 1, wherein: The first electronic component is disposed on a first surface of one of the front and back surfaces of the substrate, and the second electronic component is disposed on a second surface of the other of the front and back surfaces of the substrate. The heat transfer path penetrates the substrate in the thickness direction and extends from the heat source terminal to the idle terminal of the second electronic component.

5. The vehicle circuit board according to claim 1, wherein: The idle terminals are input and output terminals having a communication function.

6. The vehicle circuit board according to claim 1, wherein: The idle terminals are terminals for information storage.

7. The vehicle circuit board according to claim 1, wherein: The maximum value of the current input to the first electronic component is greater than the maximum value of the current input to the second electronic component.

8. The vehicle circuit board according to claim 1, wherein: The first electronic component is a power device.

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