Wiring board

Abstract

To suppress heat generation from a foil pattern on a wiring board.SOLUTION: A wiring board includes a foil pattern that connects a first terminal that outputs a current from an electronic component and a second terminal that outputs the current to an electronic component, among terminals of one or more electronic components, and flows a current from the first terminal to the second terminal, and a current dividing member that electrically connects a first position to which the first terminal is connected and a second position to which the second terminal is connected among positions of the foil pattern in parallel to the foil pattern, and divides a portion of the current flowing between the first position and the second position.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wiring board. [Background technology]

[0002] 2. Description of the Related Art Conventionally, heat dissipation members for wiring boards (printed boards) have been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-258539 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional technologies only dissipate heat generated by current flowing through a wiring pattern (e.g., a foil pattern made of copper foil) of a wiring board, and have the problem that they are unable to reduce the heat generation of the foil pattern itself.

[0005] The present invention has been made to solve the above problems, and an object of the present invention is to provide a wiring board capable of suppressing heat generation from a foil pattern of the wiring board. [Means for solving the problem]

[0006] One embodiment of the present invention is a wiring board comprising: a foil pattern that connects between a first terminal that outputs current from an electronic component and a second terminal that outputs current to an electronic component, among terminals of one or more electronic components, thereby flowing current from the first terminal to the second terminal; and a shunt member that electrically connects in parallel to the foil pattern between a first position to which the first terminal is connected and a second position to which the second terminal is connected, among positions of the foil pattern, thereby shunting a portion of the current flowing between the first position and the second position.

[0007] One embodiment of the present invention is directed to the above-mentioned wiring board, wherein the diversion member has a first portion that rises in a direction away from the wiring board at the first position, a second portion that runs along the surface of the wiring board between the first position and the second position, and a third portion that falls toward the wiring board at the second position.

[0008] In one embodiment of the present invention, in the wiring board described above, the flow diverter member is disposed inside an outer edge of the foil pattern when viewed from a normal direction of a solder surface of the wiring board.

[0009] In one embodiment of the present invention, in the wiring board described above, the current dividing member is formed by bending a metal wire having a constant wire diameter.

[0010] In one embodiment of the present invention, in the wiring board described above, the current dividing member is connected to the wiring board by being soldered to the first terminal and the second terminal.

[0011] In one embodiment of the present invention, in the wiring board described above, the current dividing member is connected to the wiring board by being inserted into a hole formed in the wiring board. Effect of the Invention

[0012] According to the present invention, heat generation from the foil pattern of the wiring board can be suppressed. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram showing an example of a configuration of a wiring board according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram showing an example of a top view of the wiring board of the present embodiment. [Diagram 3] FIG. 2 is a diagram showing an example of a cross-sectional view of the wiring board of the present embodiment. [Figure 4] 2A and 2B are diagrams showing an example of a configuration of a foil pattern on the solder side of a wiring board according to the present embodiment. [Diagram 5]1 is a diagram showing an example of a configuration of a component surface of a wiring board according to an embodiment of the present invention; [Figure 6] 5A and 5B are diagrams illustrating an example of a direction of a current in a foil pattern of the wiring board of the present embodiment. [Figure 7] 5A and 5B are diagrams illustrating an example of an arrangement of flow dividing members on a wiring board according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a diagram showing an example of the configuration of a wiring board 10 according to the present embodiment. The wiring board 10 is a so-called printed wiring board. The wiring board 10 has a foil pattern 100 that connects terminals 500 of an electronic component 50 to each other.

[0015] In the following description, when necessary to indicate a direction, each axis of the xyz Cartesian coordinate system is used. In the example shown in the figure, a surface of the wiring board 10 (for example, the solder surface 11) corresponds to the xy plane, and the normal to the xy plane corresponds to the z axis. The z axis direction is also referred to as the height direction of the electronic component 50 or the thickness direction of the wiring board 10.

[0016] The wiring board 10 of this embodiment is a so-called double-sided board, and has a solder side 11 and a component side 12. The figure shows the configuration of the wiring board 10 as viewed from the solder side 11 side. It should be noted that wiring board 10 is not limited to a double-sided board, but may be a single-sided board, or a multi-layer board (for example, a four-layer board or a six-layer board) in which a plurality of double-sided boards are stacked. In addition, in this figure, the thickness of the wiring board 10 is not shown.

[0017] Electronic components 50 are arranged on the component surface 12. In this embodiment, the electronic components 50 are components that handle a relatively large current value (for example, about 1 A to 50 A) on a printed circuit board, such as a current load switching relay, a current sensor, or a DC regulator. The electronic component 50 has terminals 500 for inputting and outputting these currents. In the following description, the terminal 500 for outputting current from the electronic component 50 is also referred to as a first terminal 501, and the terminal 500 for inputting current to the electronic component 50 and the second terminal 502 are also referred to as a first terminal 501. The foil pattern 100 connects between these terminals 500 and allows electrical current to flow.

[0018] In other words, the foil pattern 100 connects between a first terminal 501 that outputs current from the electronic component 50 and a second terminal 502 that outputs current to the electronic component 50, among the terminals 500 provided on one or more electronic components 50, thereby allowing current to flow from the first terminal 501 to the second terminal 502.

[0019] Here, "terminals 500 provided on one or more electronic components 50" refers to the following two connection patterns. In the first pattern, one electronic component 50 has a first terminal 501 and a second terminal 502, and the foil pattern 100 connects between the first terminal 501 and the second terminal 502 (i.e., between the terminals 500 of one electronic component 50). In the second pattern, among the multiple electronic components 50, there are electronic components 50 (e.g., the first electronic component 51) having a first terminal 501 and electronic components 50 (e.g., the second electronic component 52) ​​having a second terminal 502, and the foil pattern 100 connects between the terminals 500 of these multiple electronic components 50 (i.e., between the first terminal 501 of the first electronic component 51 and the second terminal 502 of the second electronic component 52). The example shown in the figure illustrates the second pattern described above.

[0020] In this example, the foil pattern 100 is described as being on the solder surface 11 side, but is not limited to this. The foil pattern 100 may be disposed on the component surface 12, or may be disposed on an inner layer in a multi-layer board.

[0021] The wiring board 10 of the present embodiment includes a flow diverting member 30. The flow diverting member 30 will be described with reference to Fig. 2 and Fig. 3 in addition to Fig. 1 described above.

[0022] FIG. 2 is a diagram showing an example of a top view of the wiring board 10 of the present embodiment. FIG. 3 is a diagram showing an example of a cross-sectional view of the wiring board 10 of the present embodiment. In the example shown in the figure, electronic component 50 is placed on component surface 12. Terminals 500 of electronic component 50 pass through through holes TH and protrude toward solder surface 11. Terminals 500 are soldered to wiring board 10 at the positions of through holes TH. The current dividing member 30 is a conductor and divides a portion of the current flowing between the above-mentioned terminals 500. In this example, the current dividing member 30 is soldered to the foil pattern 100 on the solder surface 11 and the terminals 500.

[0023] In the example shown in the figure, a first terminal 501 of a first electronic component 51 passes through a first through-hole TH1 and protrudes onto the solder surface 11. A second terminal 502 of a second electronic component 52 passes through a second through-hole TH2 and protrudes onto the solder surface 11. In this example, the flow dividing member 30 has a first portion 301, a second portion 302, and a third portion 303. The first portion 301 is soldered to a first terminal 501. The third portion 303 is soldered to a second terminal 502.

[0024] In other words, the diversion member 30 electrically connects in parallel to the foil pattern 100 between a first position 201 to which the first terminal 501 is connected and a second position 202 to which the second terminal 502 is connected, thereby conducting a portion of the current flowing between the first position 201 and the second position 202.

[0025] According to the wiring board 10 configured in this manner, the current flowing through the foil pattern 100 is bypassed (diverted) to the current dividing member 30, so that the generation of heat due to the current flowing through the foil pattern 100, that is, Joule heat, is reduced. Here, when a large amount of current flows through the foil pattern 100, the amount of heat generated by the foil pattern 100 increases, and the resistance value of the foil pattern 100 rises. Therefore, the resistance value of the current dividing member 30 becomes relatively low compared to the resistance value of the foil pattern 100, the current flowing through the foil pattern 100 decreases, and the reduced current flows through the current dividing member 30. For this reason, it is considered that the current value of the foil pattern 100 and the current value of the current dividing member 30 will be balanced under certain conditions.

[0026] It should be noted that the first position 201 is not limited to the position of the first terminal 501. The first position 201 includes a portion of the foil pattern 100 that is close to the first terminal 501. For example, the first position 201 is a position of the foil pattern 100 that is closer to the first terminal 501 than the center of gravity of the area of ​​the foil pattern 100. Similarly, the second position 202 is not limited to the position of the second terminal 502. The second position 202 includes a portion of the foil pattern 100 that is close to the second terminal 502. For example, the second position 202 is a position of the foil pattern 100 that is closer to the second terminal 502 than the center of gravity of the area of ​​the foil pattern 100.

[0027] Any conductive material may be used for the current dividing member 30. For example, the current dividing member 30 may be a metal wire such as a copper wire. The surface of the current diverting member 30 is preferably coated with an insulating material. For example, the current diverting member 30 is formed using a so-called enameled wire. By coating the surface of the current diverting member 30 with an insulating material, it is possible to prevent the current diverting member 30 from being electrically short-circuited with other conductors. In particular, when a plurality of current diverting members 30 are arranged on the wiring board 10, it is possible to prevent the current diverting members 30 from coming into contact with each other and being electrically short-circuited.

[0028] In this embodiment, the enameled wire includes a wide range of known wire types, such as polyurethane copper wire (UEW), polyester copper wire (PEW), polyesterimide copper wire (EIW), polyamideimide copper wire (AIW), and polyimide copper wire (PIW).

[0029] The current dividing member 30 may have various shapes as long as it can divide part of the current flowing between the first position 201 and the second position 202.

[0030] For example, as shown in the figure, the diversion member 30 has a first portion 301 that rises in a direction away from the wiring board 10 (i.e., in the +z direction) at the first position 201, a second portion 302 that runs along the surface of the wiring board 10 between the first position 201 and the second position 202, and a third portion 303 that falls toward the wiring board 10 at the second position 202 (i.e., in the -z direction).

[0031] That is, the flow diverting member 30 forms a space between the second portion 302 and the foil pattern 100, the space being equal to the height of the first portion 301 and the third portion 303. The flow diverting member 30 configured in this manner can ensure air permeability (ventilation) between the second portion 302 and the foil pattern 100, making it easier to dissipate heat from the flow diverting member 30 and the foil pattern 100.

[0032] Alternatively, the flow diverting member 30 may be formed by bending a metal wire with a constant wire diameter. For example, the flow diverting member 30 is formed by bending an enameled wire with a constant wire diameter (for example, 1 mm to 3 mm). The flow diverting member 30 thus formed can be manufactured relatively inexpensively.

[0033] The current dividing member 30 is connected to the wiring board 10 by being soldered to the first terminal 501 and the second terminal 502. Note that the solder is not shown in the figure. According to the wiring board 10 configured in this manner, the current dividing member 30 is directly connected to the first terminal 501 and the second terminal 502, which are the current sources, via solder, so that more current can be passed through the current dividing member 30, thereby further reducing the current flowing through the foil pattern 100. Furthermore, with the wiring board 10 configured in this manner, the same process as that used for soldering the electronic components 50 can be used, and productivity can be improved.

[0034] To improve heat resistance, it is also possible to use polyesterimide copper wire (EIW; heat resistance class H), polyamideimide copper wire (AIW; heat resistance class N), polyimide copper wire (PIW; heat resistance class R), etc. However, in the case of such wire types, the soldering performance may be lower than that of polyurethane copper wire (UEW; heat resistance class E). In cases where such soldering performance is relatively low, the flow diverter member 30 may be configured to be press-fitted into a hole formed in the wiring board 10, or may be inserted into the hole and then fixed by another fixing method.

[0035] That is, the flow diverting member 30 may be connected to the wiring board 10 by being inserted into a hole formed in the wiring board 10. The wiring board 10 configured in this manner allows the use of the flow diverting member 30 made of a material with high heat resistance and low soldering performance.

[0036] As long as there is no contact between adjacent flow diverting members 30 or with electronic components, wiring boards, or the housing that houses the wiring boards, it is preferable to increase the surface area of ​​the flow diverting members 30 that comes into contact with the air, as this can improve heat dissipation. Methods for increasing the surface area of ​​the flow diverting member 30 include increasing the wire diameter of the flow diverting member 30 and providing irregularities on the surface of the flow diverting member 30 .

[0037] Next, a specific example of the configuration of wiring board 10 will be described with reference to FIGS. 4 is a diagram showing an example of the configuration of foil pattern 100 on solder side 11 of wiring board 10 of the present embodiment. In this example, first foil pattern 101, second foil pattern 102, third foil pattern 103, fourth foil pattern 104, and fifth foil pattern 105 are arranged on solder side 11 of wiring board 10. First foil pattern 101 to fifth foil pattern 105 are connected to electronic components 50 that handle a relatively large current value (for example, approximately 1 A to 50 A). In addition, in this figure, the flow dividing member 30 is omitted.

[0038] 5 is a diagram showing an example of the configuration of component surface 12 of wiring board 10 of the present embodiment. That is, in this figure, wiring board 10 shown in FIG. 4 is flipped left to right to show the back side of solder surface 11. In this example, a first electronic component 51, a second electronic component 52, a third electronic component 53, a fourth electronic component 54, and a fifth electronic component 55 are arranged on component surface 12. As an example, the first electronic component 51 and the fourth electronic component 54 are connectors (e.g., quick-connect terminals) for connecting to an external device. The second electronic component 52 and the fifth electronic component 55 are relays for switching a current load. The third electronic component 53 is a current sensor.

[0039] 6 is a diagram showing an example of the direction of a current in the foil pattern 100 of the wiring board 10 of this embodiment. The first foil pattern 101 has a first position 211 and a second position 212, and a current flows from the first position 211 to the second position 212. The second foil pattern 102 has a first position 221 and a second position 222, and a current flows from the first position 221 to the second position 222. Similarly to the above, the third foil pattern 103, the fourth foil pattern 104, and the fifth foil pattern 105 also have a current flow from the first position 201 (the first position 231, the first position 241, and the first position 251) to the second position 202 (the second position 232, the second position 242, and the second position 252). In the figure, the arrow on the foil pattern 100 indicates the direction of the current. Also, in the figure, the current dividing member 30 is omitted.

[0040] 7 is a diagram showing an example of the arrangement of the diverting members 30 of the wiring board 10 of the present embodiment. The first diverting member 31 is arranged on the first foil pattern 101 so as to connect the first position 211 and the second position 212. The second diverting member 32 is arranged on the second foil pattern 102 so as to connect the first position 221 and the second position 222. Similarly to the above, the third foil pattern 103, the fourth foil pattern 104, and the fifth foil pattern 105 are also arranged with the diverting members 30 (the third diverting member 33, the fourth diverting member 34, and the fifth diverting member 35) arranged so as to connect the first position 201 (the first position 231, the first position 241, and the first position 251) and the second position 202 (the second position 232, the second position 242, and the second position 252).

[0041] Here, the flow dividing member 30 is disposed inside the outer edge of the foil pattern 100 when viewed from the normal direction of the solder surface 11 of the wiring board 10 (for example, as shown in FIG. 7). As an example, the second diverting member 32 is disposed inside the outer edge of the second foil pattern 102. The third diverting member 33 is disposed inside the outer edge of the third foil pattern 103. Similarly to the above, for the fourth foil pattern 104 and the fifth foil pattern 105, the diverting members 30 (fourth diverting member 34 and fifth diverting member 35) are disposed inside the outer edges of the foil pattern 100 (fourth foil pattern 104 and fifth foil pattern 105).

[0042] Generally, when a plurality of foil patterns 100 are provided on wiring board 10, foil patterns 100 are arranged so as not to electrically contact adjacent foil patterns 100. According to wiring board 10 of the present embodiment, since flow diverting members 30 are arranged on the inside of the outer edge of foil pattern 100, when a plurality of flow diverting members 30 are provided, adjacent flow diverting members 30 can be prevented from electrically contacting each other. Furthermore, with the wiring board 10 configured in this manner, the current diverting member 30 is linearly arranged inside the foil pattern 100, so that the first position 201 and the second position 202 can be connected over a relatively short distance. As a result, the resistance value of the current diverting member 30 is smaller than when the current diverting member 30 is not linearly arranged, and more current can be bypassed to the current diverting member 30. Therefore, with the wiring board 10 of this embodiment, the current value of the foil pattern 100 can be reduced, and heat generation can be suppressed.

[0043] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and appropriate modifications can be made without departing from the spirit of the present invention. The configurations described in the above-mentioned embodiments may be combined. [Explanation of symbols]

[0044] 10...wiring board, 30...current dividing member, 50...electronic component, 100...foil pattern, 201...first position, 202...second position, 501...first terminal, 502...second terminal

Claims

1. a foil pattern that connects a first terminal that outputs a current from the electronic component and a second terminal that outputs a current to the electronic component, among terminals of one or more electronic components, and passes a current from the first terminal to the second terminal; a current dividing member electrically connected in parallel to the foil pattern between a first position to which the first terminal is connected and a second position to which the second terminal is connected among the positions of the foil pattern, and dividing a part of the current flowing between the first position and the second position; A wiring board comprising:

2. The flow dividing member has a first portion that rises in a direction away from the wiring board at the first position, a second portion that runs along a surface of the wiring board between the first position and the second position, and a third portion that falls toward the wiring board at the second position. The wiring board according to claim 1 .

3. The flow dividing member is disposed inside an outer edge of the foil pattern when viewed from a normal direction of the solder surface of the wiring board. The wiring board according to claim 1 .

4. The flow dividing member is formed by bending a metal wire having a constant wire diameter. The wiring board according to claim 1 .

5. The current dividing member is connected to the wiring board by being soldered to the first terminal and the second terminal. The wiring board according to claim 1 .

6. The flow dividing member is connected to the wiring board by being inserted into a hole formed in the wiring board. The wiring board according to claim 1 .

Images