Electronic substrate device and brake control device

Abstract

To provide an electronic substrate device capable of making a large current flow between a power source and a load as one example.SOLUTION: An electronic substrate device according to an embodiment includes, as an example, an insulating material having a first outer surface and a second outer surface located on an opposite side of the first outer surface, a first conductor pattern provided on the insulating material, a first via penetrating the insulating material and connected to the first conductor pattern and electrically connected to a power supply through the first conductor pattern, a second conductor pattern provided on the insulating material, a second via penetrating the insulating material and connected to the second conductor pattern and electrically connected to a load through the second conductor pattern, and a first via provided on the first outer surface and connected to the first via and the second via and peeling off from the first outer surface due to a difference in thermal expansion from the insulating material at a threshold temperature or higher, and a fuse pattern that interrupts a current between the power supply and the load when the fuse pattern is cut.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] An embodiment of the present invention relates to an electronic board device and a brake control device. [Background technology]

[0002] Conventionally, various devices, such as a brake control device, include an electronic board device that drives a load such as an actuator. To cut off an overcurrent between a power source and the load, the electronic board device has a fuse pattern that can be blown by the overcurrent (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-062891 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional configurations, the fuse pattern is set to be thin in order to melt it, which reduces the allowable current between the power supply and the load.

[0005] Therefore, the present invention has been made in view of the above, and provides an electronic board device and a brake control device that are capable of passing a large current between a power source and a load. [Means for solving the problem]

[0006] As an example, an electronic board device according to an embodiment of the present invention includes an insulating material having a first outer surface and a second outer surface located opposite the first outer surface, a first conductor pattern provided in the insulating material, a first via penetrating the insulating material, connected to the first conductor pattern, and configured to be electrically connected to a power source through the first conductor pattern, a second conductor pattern provided in the insulating material, a second via penetrating the insulating material, connected to the second conductor pattern, and configured to be electrically connected to a load through the second conductor pattern, and a fuse pattern provided on the first outer surface, connected to the first via and the second via, configured to peel off from the first outer surface due to a difference in thermal expansion with the insulating material at a temperature equal to or higher than a threshold temperature, and configured to interrupt current between the power source and the load when blown. Therefore, for example, when an overcurrent occurs between the power supply and the load, the temperature of the electronic board device rises due to the electrical resistance of the first conductor pattern, the first via, the second conductor pattern, the second via, and the fuse pattern. When the temperature of the electronic board device exceeds a threshold temperature, the fuse pattern peels off from the first outer surface. The fuse pattern can be more easily peeled off from the first outer surface than when it is provided inside the insulating material. The portion of the fuse pattern that peels off from the first outer surface has difficulty dissipating heat to the insulating material by thermal conduction, and also to the first and second vias, causing a rapid temperature rise. The overheated fuse pattern melts and interrupts the overcurrent between the power supply and the load. That is, the fuse pattern is more likely to melt when peeled off from the first outer surface. Therefore, the electronic board device does not need to have a thin fuse pattern to melt, and can pass a large current between the power supply and the load. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view that schematically illustrates a brake system according to one embodiment. [Figure 2] FIG. 2 is a plan view showing a part of the electronic substrate device of the embodiment. [Figure 3]FIG. 3 is a circuit diagram that schematically shows the configuration of a drive circuit for the motor in the electric cylinder device of the above embodiment. [Figure 4] FIG. 4 is a cross-sectional view schematically showing a part of the electronic substrate device of the embodiment taken along line F4-F4 in FIG. [Figure 5] FIG. 5 is a cross-sectional view that schematically shows a part of an electronic substrate device in which an overcurrent has been interrupted by the interruption mechanism of the above embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment will be described below with reference to FIGS. 1 to 5. In this specification, components according to the embodiment and descriptions of the components may be described using multiple expressions. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may also be identified by names different from those in this specification. Furthermore, the components may also be described using expressions different from those in this specification.

[0009] In the following description, "inhibit" is defined as, for example, preventing an event, action, or effect from occurring or reducing the magnitude of an event, action, or effect.

[0010] 1 is a cross-sectional view that schematically shows a brake system 10 according to this embodiment. The brake system 10 is mounted on a vehicle 1 such as a four-wheeled automobile. However, the brake system 10 is not limited to this example.

[0011] The brake system 10 includes a brake control device 11 and a plurality of wheel cylinders 12. The brake control device 11 may also be referred to as a brake fluid pressure control device. The brake system 10 may further include various other components such as a master cylinder, a pump, and a solenoid valve.

[0012] The brake control device 11 controls, for example, the hydraulic pressure of at least one of the plurality of wheel cylinders 12. The brake control device 11 includes an electric cylinder device 21, an electronic control unit (ECU) 22, and a plurality of hydraulic paths 23.

[0013] The electric cylinder device 21 is connected to at least one of the plurality of wheel cylinders 12 via a fluid path 23. The electric cylinder device 21 can increase the pressure of the brake fluid in the wheel cylinder 12 to generate a braking force for the vehicle 1.

[0014] The electric cylinder device 21 has a motor 25 and a pressure adjusting device 26. The motor 25 is an example of a load and an actuator. The actuator is not limited to the motor 25, and may be another actuator such as a solenoid actuator. The load is not limited to the actuator, and may be another device that consumes power.

[0015] The motor 25 is, for example, a three-phase brushless motor. However, other types of motors may be used as the motor 25. The motor 25 is controlled by the ECU 22, for example, to drive the pressure regulator 26.

[0016] The pressure regulating device 26 includes a housing 31, a piston 32, two seals 33 and 34, a reservoir 35, a rotary-to-linear motion conversion mechanism 36, and a speed reduction mechanism 37. The ECU 22 and the motor 25 are located outside the housing 31. However, the ECU 22 and the motor 25 may be located inside the housing 31.

[0017] An internal space 41 is provided inside the housing 31. The internal space 41 is a substantially cylindrical space extending along a central axis Axc. The central axis Axc is, for example, a virtual central axis of the internal space 41. Note that the central axis of the internal space 41 may be different from the central axis Axc.

[0018] For convenience, the axial direction and the radial direction are defined herein. The axial direction is a direction along the central axis Axc. The axial direction includes a forward direction Df and a rearward direction Db. The forward direction Df is a direction along the central axis Axc. The rearward direction Db is the opposite direction to the forward direction Df. The radial direction is a direction perpendicular to the central axis Axc.

[0019] The housing 31 is further provided with an output port 42 and an input port 43. The output port 42 and the input port 43 each communicate with the internal space 41. In the axial direction, the output port 42 is spaced apart from the input port 43 in the forward direction Df.

[0020] The piston 32 is disposed in the internal space 41. The piston 32 is able to move axially within the internal space 41. The piston 32 defines a portion of the internal space 41 as a fluid chamber 45. That is, the fluid chamber 45 is provided in the pressure adjusting device 26. The fluid chamber 45 is provided axially between the piston 32 and the end of the internal space 41 in the forward direction Df. The fluid chamber 45 is filled with brake fluid. In other words, the fluid chamber 45 contains brake fluid.

[0021] The output port 42 is connected to a fluid chamber 45. The fluid chamber 45 is connected to the wheel cylinder 12 through the output port 42 and the fluid passage 23. The piston 32 reduces the volume of the fluid chamber 45 by moving forward Df. This allows the electric cylinder device 21 to increase the pressure of the brake fluid in the fluid chamber 45 and the wheel cylinder 12.

[0022] On the other hand, the piston 32 moves in the rear direction Db to increase the volume of the fluid chamber 45. This allows the electric cylinder device 21 to reduce the pressure of the brake fluid in the fluid chamber 45 and the wheel cylinder 12.

[0023] A gap is provided between the housing 31 and the piston 32 in the radial direction, allowing the piston 32 to move axially relative to the housing 31. Two seals 33, 34 seal the gap.

[0024] The seal 33 is spaced from the seal 34 in the forward direction Df. In the axial direction, the output port 42 communicates with the liquid chamber 45 at a position spaced from the seal 33 in the forward direction Df. In the axial direction, the input port 43 communicates with the internal space 41 between the two seals 33, 34. The seal 33 seals between the liquid chamber 45 and the input port 43.

[0025] The reservoir 35 is connected to the input port 43 through the fluid path 23. The reservoir 35 stores brake fluid. For example, the reservoir 35 is open to the atmosphere, so that the pressure of the reservoir 35 is maintained at atmospheric pressure.

[0026] When the piston 32 moves rearward Db beyond a predetermined position, the input port 43 and the fluid chamber 45 communicate with each other. This allows the brake fluid to flow freely between the fluid chamber 45 and the reservoir 35, and the pressure in the fluid chamber 45 drops to atmospheric pressure.

[0027] The rotary-to-linear motion conversion mechanism 36 is disposed in the internal space 41. In this embodiment, the rotary-to-linear motion conversion mechanism 36 is, for example, a ball screw. The rotary-to-linear motion conversion mechanism 36 has a rotating member 51, a linear motion member 52, and a plurality of balls 53.

[0028] The rotating member 51 is formed in a generally cylindrical shape extending along the central axis Axc. The linear moving member 52 is formed in a generally cylindrical shape extending along the central axis Axc. The rotating member 51 extends through a hole inside the linear moving member 52. The linear moving member 52 is attached to or supports the piston 32.

[0029] A male screw is provided on the rotating member 51. On the other hand, a female screw is provided on the linear moving member 52. The linear moving member 52 may further be provided with a circulation path connecting both ends of the female screw. The plurality of balls 53 are, for example, held by the female screw of the linear moving member 52 so as to be able to roll and circulate, and are fitted into the male screw of the rotating member 51. Therefore, the linear moving member 52 is attached to the rotating member 51 via the balls 53.

[0030] The speed reduction mechanism 37 has a plurality of gears that mesh with each other. The speed reduction mechanism 37 is not limited to the example shown in Figure 1, and may be another speed reduction mechanism such as a planetary gear mechanism. The speed reduction mechanism 37 is provided between the motor 25 and the rotating member 51.

[0031] The motor 25 rotates the rotating member 51 around the central axis Axc through the speed reduction mechanism 37. The speed reduction mechanism 37 may be omitted. For example, the motor 25 may rotate the rotating member 51 directly.

[0032] When the motor 25 rotates the rotating member 51 in one direction (forward direction) around the central axis Axc, the rotating member 51 pushes the linearly moving member 52 in the forward direction Df via the ball 53. Furthermore, the linearly moving member 52 pushes the piston 32 in the forward direction Df. As a result, the linearly moving member 52 and the piston 32 move (advance) in the forward direction Df. By moving in the forward direction Df, the piston 32 reduces the volume of the liquid chamber 45 and increases the pressure in the liquid chamber 45.

[0033] On the other hand, when the motor 25 rotates the rotating member 51 in the direction opposite to the forward rotation direction (reverse direction), the rotating member 51 pushes the linearly moving member 52 in the rearward direction Db via the ball 53. The piston 32 moves (retracts) in the rearward direction Db together with the linearly moving member 52. By moving in the rearward direction Db, the piston 32 increases the volume of the liquid chamber 45 and reduces the pressure in the liquid chamber 45. As described above, the pressure adjusting device 26 is driven by the motor 25 to change the pressure in the liquid chamber 45.

[0034] The ECU 22 has a case 61 and an electronic board device 62. The case 61 houses the electronic board device 62. The case 61 is sealed watertight to protect the electronic board device 62. However, the case 61 is not limited to this example.

[0035] Fig. 2 is a plan view showing a part of an electronic board device 62 of this embodiment. As shown in Fig. 2, the electronic board device 62 has a board 71 and an inductor 72. The inductor 72 is an example of an electronic component.

[0036] Fig. 3 is a circuit diagram that schematically shows the configuration of a drive circuit for the motor 25 in the electric cylinder device 21 of this embodiment. As shown in Fig. 3, the electronic board device 62 further includes an inverter circuit 73 and a power transistor 74. The electronic board device 62 further includes a microcontroller, a sensor, a capacitor, and various other components.

[0037] The electronic board device 62 is connected to a power source P. The electronic board device 62 supplies power to the motor 25 through an inductor 72, a power transistor 74, and an inverter circuit 73, thereby driving the motor 25.

[0038] The inverter circuit 73 includes semiconductor elements such as multiple metal oxide semiconductor field effect transistors (MOSFETs). The inverter circuit 73 may include other types of transistors or other electronic components. The inverter circuit 73 generates U-phase, V-phase, and W-phase drive signals (currents) from the power supply voltage supplied from the power supply P and supplies the drive signals to the motor 25.

[0039] The power transistor 74 is provided between the inverter circuit 73 and the power supply P. The power transistor 74 is a semiconductor element such as a MOSFET. However, the power transistor 74 is not limited to this example. The power transistor 74 switches the power supply to the motor 25. That is, the power transistor 74 is a semiconductor element that drives the motor 25.

[0040] The inductor 72 is provided between the power transistor 74 and the power supply P. The inductor 72, for example, removes noise from the current supplied to the power transistor 74. Note that the inductor 72 is not limited to this example.

[0041] An inductor 72, a MOSFET of an inverter circuit 73, and a power transistor 74 are mounted on the substrate 71. Other components such as a microcontroller, sensors, and capacitors are also mounted on the substrate 71.

[0042] 4 is a cross-sectional view schematically showing a portion of the electronic board device 62 of this embodiment taken along line F4-F4 in FIG. 2. As shown in FIG. 4, the board 71 of this embodiment is a multilayer printed wiring board. However, the board 71 is not limited to this example. The board 71 has an insulating material 81, a pattern 82, and two solder resists 83 and 84. For ease of understanding, the solder resist 83 is omitted from FIG. 2.

[0043] As shown in Fig. 4, the insulating material 81 has a plurality of laminated insulating layers 90. The plurality of insulating layers 90 are made of, for example, synthetic resin. Note that the material of the insulating layers 90 is not limited to this example. The plurality of insulating layers 90 includes two outer layers 91 and 92 and a plurality of inner layers 93. Note that the inner layer 93 may be omitted.

[0044] Each of the outer layers 91 and 92 is one of the outermost layers among the plurality of stacked insulating layers 90. Each of the inner layers 93 is one of the plurality of stacked insulating layers 90 that is located between the two outer layers 91 and 92.

[0045] The insulating material 81 further has two flat outer surfaces 81a and 81b. The outer surface 81a is an example of a first outer surface. The outer surface 81b is an example of a second outer surface. The outer surface 81b is located on the opposite side of the outer surface 81a.

[0046] The outer surfaces 81a and 81b are provided on both ends of the insulating material 81 in the direction in which the multiple insulating layers 90 are stacked. The outer surface 81a is one surface of the outer layer 91. The outer surface 81b is one surface of the outer layer 92. The multiple insulating layers 90 are located between the two outer surfaces 81a and 81b of the insulating material 81.

[0047] The pattern 82 is a conductor provided on the insulating material 81. The pattern 82 has a plurality of conductive layers 101 and a plurality of vias 102. The pattern 82 may further include other patterns. The conductive layers 101 and the vias 102 are made of a metal such as copper. Therefore, the pattern 82 has a different thermal expansion coefficient from the insulating material 81.

[0048] The plurality of conductive layers 101 includes two outer layers 105 and 106 and a plurality of inner layers 107. The outer layer 105 is one of the plurality of conductive layers 101 that is provided on the outer surface 81a of the insulating material 81. The outer layer 106 is one of the plurality of conductive layers 101 that is provided on the outer surface 81b of the insulating material 81. Each of the plurality of inner layers 107 is one of the plurality of conductive layers 101 that is provided between two adjacent ones of the plurality of insulating layers 90.

[0049] The vias 102 are, for example, plated through holes. However, the vias 102 may be other vias. Each of the vias 102 penetrates the insulating material 81 and connects at least two of the conductive layers 101.

[0050] The solder resist 83 covers the outer surface 81a of the insulating material 81 and a part of the outer layer 105 of the conductive layer 101. The solder resist 84 covers the outer surface 81b of the insulating material 81 and a part of the outer layer 106 of the conductive layer 101. The solder resists 83 and 84 cover, for example, the wiring of the outer layers 105 and 106, and expose the pads.

[0051] 3, the pattern 82 has an upstream pattern 111, a downstream pattern 112, and a cutoff mechanism 113 between the power supply P and the power transistor 74. The upstream pattern 111 is connected to the power supply P. The downstream pattern 112 is connected to the power transistor 74. The cutoff mechanism 113 is provided between the upstream pattern 111 and the downstream pattern 112.

[0052] The upstream pattern 111 has a power supply terminal 121 shown in Fig. 2, and a first conductor pattern 122 and a plurality of first vias 123 shown in Fig. 4. As shown in Fig. 2, the power supply terminal 121 is, for example, a plated through hole, and is included in the plurality of vias 102. Therefore, the power supply terminal 121 penetrates the insulating material 81. The power supply terminal 121 is connected to a power supply P. Note that the power supply terminal 121 may be another terminal such as a pad.

[0053] The first conductor pattern 122 is included in the plurality of conductive layers 101. As shown in FIG. 4, the first conductor pattern 122 has two external patterns 125 and 126 and a plurality of internal patterns 127. The external pattern 125 is an example of a first external pattern. The external pattern 126 is an example of a second external pattern. The internal pattern 127 is an example of a first internal pattern.

[0054] The external pattern 125 is included in the outer layer 105. That is, the external pattern 125 is provided on the outer surface 81a of the insulating material 81. The external pattern 126 is included in the outer layer 106. That is, the external pattern 126 is provided on the outer surface 81b of the insulating material 81. The multiple internal patterns 127 are included in the multiple internal layers 107. That is, each of the multiple internal patterns 127 is provided between two adjacent ones of the multiple insulating layers 90.

[0055] The plurality of first vias 123 are, for example, plated through holes and are included in the plurality of vias 102. Therefore, each of the plurality of first vias 123 penetrates the insulating material 81. As shown in Fig. 2, the plurality of first vias 123 are arranged, for example, in a grid pattern.

[0056] One end of each of the external patterns 125, 126 and the internal pattern 127 is connected to the power supply terminal 121. The other end of each of the external patterns 125, 126 and the internal pattern 127 is connected to a plurality of first vias 123. That is, the first vias 123 are connected to the first conductor pattern 122. The first vias 123 are electrically connected to the power supply P through the first conductor pattern 122 and the power supply terminal 121.

[0057] The downstream pattern 112 has a second conductor pattern 131 and a plurality of second vias 132 shown in FIG. 4, and a connection pattern 133 shown in FIG. 3. As shown in FIG. 4, the second conductor pattern 131 is included in a plurality of conductive layers 101. The second conductor pattern 131 has two external patterns 135 and 136 and a plurality of internal patterns 137. The external pattern 135 is an example of a third external pattern. The external pattern 136 is an example of a fourth external pattern. The internal pattern 137 is an example of a second internal pattern.

[0058] The external pattern 135 is included in the outer layer 105. That is, the external pattern 135 is provided on the outer surface 81a of the insulating material 81. The external pattern 136 is included in the outer layer 106. That is, the external pattern 136 is provided on the outer surface 81b of the insulating material 81. The multiple internal patterns 137 are included in the multiple internal layers 107. That is, each of the multiple internal patterns 137 is provided between two adjacent ones of the multiple insulating layers 90.

[0059] The plurality of second vias 132 are, for example, plated through holes and are included in the plurality of vias 102. Therefore, each of the plurality of second vias 132 penetrates the insulating material 81. As shown in Fig. 2, the plurality of second vias 132 are arranged, for example, in a grid pattern.

[0060] 4, one end of each of the external patterns 135 and 136 and the internal pattern 137 is connected to a plurality of second vias 132. That is, the second vias 132 are connected to the second conductor pattern 131.

[0061] 3, the connection pattern 133 is provided between the second conductor pattern 131 and the power transistor 74. The connection pattern 133 has, for example, a plurality of through holes 138 and a wiring pattern 139. Note that the connection pattern 133 is not limited to this example.

[0062] The through holes 138 are, for example, plated through holes, and are included in the plurality of vias 102. The other ends of the external patterns 135, 136 and the internal pattern 137 are connected to the plurality of through holes 138. That is, the second conductor pattern 131 is provided between the second via 132 and the through holes 138.

[0063] The wiring pattern 139 is included in, for example, the outer layer 106 and is continuous with the external pattern 136. The wiring pattern 139 connects the plurality of through holes 138 to the terminals of the power transistor 74. Therefore, the second via 132 is electrically connected to the motor 25 through the second conductor pattern 131, the connection pattern 133, the power transistor 74, and the inverter circuit 73.

[0064] As shown in FIG. 4 , the interruption mechanism 113 has a fuse pattern 140. The fuse pattern 140 is included in the outer layer 105 of the conductive layer 101. Therefore, the fuse pattern 140 is provided on the outer surface 81 a of the insulating material 81. The fuse pattern 140 has a first wiring 141 and a second wiring 142. In this embodiment, the fuse pattern 140 is provided only on the outer surface 81 a of the insulating material 81.

[0065] The first wiring 141 is connected to the plurality of first vias 123. The first wiring 141 is continuous with the external pattern 125 of the first conductor pattern 122. As shown in FIG. 2, the width of the first wiring 141 is wider than half the width of each of the external patterns 125, 126 and the internal pattern 127. Note that the first wiring 141 is not limited to this example.

[0066] The second wiring 142 is connected to the plurality of second vias 132. The second wiring 142 is continuous with the external pattern 135 of the second conductor pattern 131. The width of the second wiring 142 is wider than half the width of each of the external patterns 135, 136 and the internal pattern 137. Note that the second wiring 142 is not limited to this example.

[0067] The first wiring 141 is longer than the second wiring 142. For example, the length of the first wiring 141 is more than twice the length of the second wiring 142. Note that the lengths of the first wiring 141 and the second wiring 142 are not limited to this example.

[0068] A first pad 141a is provided at an end of the first wiring 141. A second pad 142a is provided at an end of the second wiring 142. The first pad 141a and the second pad 142a are not covered with the solder resist 83 and are exposed.

[0069] The inductor 72 is disposed on the outer surface 81a of the insulating material 81 and is connected to the first pad 141a and the second pad 142a. The inductor 72 has a first terminal 151 and a second terminal 152.

[0070] The first terminal 151 is joined to the first pad 141a by, for example, solder 153. That is, the first wiring 141 is provided upstream of the inductor 72 and the second wiring 142, and connects the first terminal 151 to the multiple first vias 123.

[0071] The second terminal 152 is joined to the second pad 142a by, for example, solder 154. That is, the second wiring 142 connects the second terminal 152 to the plurality of second vias 132.

[0072] If a fault occurs in the electrical path between the power supply P and the motor 25, an overcurrent may flow through the upstream pattern 111, the downstream pattern 112, and the cutoff mechanism 113. However, the cutoff mechanism 113 of this embodiment can cut off the overcurrent, for example, before the overcurrent causes burnout.

[0073] For example, when an overcurrent flows, the fuse pattern 140 of the interruption mechanism 113 generates heat due to electrical resistance. When an overcurrent flows through the fuse pattern 140, the upstream pattern 111 and the downstream pattern 112 may also generate heat due to the overcurrent.

[0074] 5 is a cross-sectional view schematically illustrating a portion of an electronic substrate device 62 in which an overcurrent has been interrupted by the interruption mechanism 113 of this embodiment. Heat generated by the upstream pattern 111, the downstream pattern 112, and the interruption mechanism 113 causes the temperature of the substrate 71 to rise. This causes thermal expansion of the insulating material 81 and the pattern 82. As schematically indicated by the arrows in FIG. 5, the insulating material 81 thermally expands more than the pattern 82.

[0075] One end of the first wiring 141 is fixed to the insulating material 81 by a plurality of first vias 123. The other end of the first wiring 141 is fixed to the inductor 72 by, for example, solder 153, and is fixed to the insulating material 81 via the inductor 72. In other words, both ends of the first wiring 141 are restrained by the insulating material 81.

[0076] The first wiring 141 thermally expands between the restrained ends. However, the thermal expansion of the first wiring 141 is smaller than the thermal expansion of the insulating material 81. Therefore, stress occurs in the adhesive portion between the first wiring 141 and the outer surface 81a of the insulating material 81.

[0077] For example, at 180° C. or higher, the thermal expansion coefficient of the insulating material 81 is 10 times or more the thermal expansion coefficient of the pattern 82. However, the thermal expansion coefficients of the insulating material 81 and the pattern 82 are not limited to this example.

[0078] The first wiring 141 is bonded to the outer surface 81a of the insulating material 81 by, for example, heat pressing. However, when the temperature of the insulating material 81 rises, the insulating material 81 softens, reducing the adhesive strength between the first wiring 141 and the outer surface 81a.

[0079] The first wiring 141 is adhered to the outer surface 81a of the insulating material 81 and is not covered by the other insulating layer 90. In other words, the other insulating layer 90 does not hold the first wiring 141 to the outer surface 81a. On the other hand, although the solder resist 83 covers the first wiring 141, the force with which the solder resist 83 holds the first wiring 141 is weak.

[0080] When the temperature of the first wiring 141 and the insulating material 81 rises above a predetermined threshold temperature, the first wiring 141 peels off from the outer surface 81a due to a difference in thermal expansion between the first wiring 141 and the insulating material 81 and a decrease in adhesive strength. The threshold temperature is set, for example, to a temperature higher than the rated temperature of the electronic board device 62 and lower than a temperature at which burnout may occur. In other words, during normal operation of the brake system 10, the temperatures of the first wiring 141 and the insulating material 81 are lower than the threshold temperature.

[0081] When first wiring 141 is adhered to outer surface 81a, it can dissipate heat to insulating material 81 by thermal conduction. However, when first wiring 141 is peeled off from outer surface 81a, it becomes difficult for first wiring 141 to dissipate heat to insulating material 81. Therefore, the temperature of first wiring 141 that has peeled off from outer surface 81a rises more rapidly than other parts of substrate 71.

[0082] The first wiring 141 can dissipate heat to other parts of the substrate 71, for example, through the first via 123. However, the thermal conduction from the first wiring 141 that has peeled off from the outer surface 81a to other parts of the substrate 71 is smaller than the thermal conduction from the first wiring 141 that is adhered to the outer surface 81a to the insulating material 81. For this reason, when the temperature of the first wiring 141 rises rapidly, the temperature of other parts of the substrate 71 and the components around the first wiring 141 rises less easily than that of the first wiring 141, and the temperatures remain within the rated temperature range.

[0083] The first wiring 141 will eventually melt due to a rapid temperature rise. In the electrical path between the power supply P and the motor 25, the first via 123 and the second via 132 are connected by a single fuse pattern 140 and are not connected in parallel by other wiring. Furthermore, the electronic board device 62 does not have any other path that bypasses the fuse pattern 140 and electrically connects the power supply P and the motor 25. Therefore, when the first wiring 141 melts, the fuse pattern 140 cuts off the current between the power supply P and the motor 25.

[0084] When the first wiring 141 melts and cuts off the current between the power supply P and the motor 25, the supply of power to the inductor 72, the power transistor 74, the inverter circuit 73, and the motor 25 is cut off. This stops the motor 25, and heat generation in the electronic components and wiring also stops. This prevents the electronic board device 62 from being burned due to an overcurrent, for example.

[0085] The first wiring 141 is located upstream of the inductor 72, the power transistor 74, the inverter circuit 73, and the motor 25. Because the first wiring 141 cuts off the current at an upstream position, it is possible to more reliably prevent the inductor 72, the power transistor 74, the inverter circuit 73, and the motor 25 from being burned out.

[0086] As described above, the first wiring 141 rapidly rises in temperature as it peels off from the outer surface 81a and eventually melts down. That is, the first wiring 141 does not need to be thinned in order to melt down while it is attached to the outer surface 81a. For this reason, the fuse pattern 140 (first wiring 141 and second wiring 142) is set to have a relatively wide width, has a large allowable current, and can pass a large current. By increasing the width (cross-sectional area), the fuse pattern 140 can reduce electrical resistance, which in turn reduces heat generation during normal operation.

[0087] The first wiring 141 melts down when an overcurrent flows through it. However, the first wiring 141 is formed by a typical method for forming a conductor pattern. That is, the first wiring 141, together with the other parts of the outer layer 105, is provided on the outer surface 81a of the insulating material 81 by etching and heat pressing copper foil.

[0088] In the brake system 10 according to the present embodiment described above, the first via 123 penetrates the insulating material 81 and is connected to the first conductor pattern 122, and is configured to be electrically connected to the power source P through the first conductor pattern 122. The second via 132 penetrates the insulating material 81 and is connected to the second conductor pattern 131, and is configured to be electrically connected to a load such as the motor 25 through the second conductor pattern 131. The fuse pattern 140 is provided on the outer surface 81a and is connected to the first via 123 and the second via 132. The fuse pattern 140 is configured to peel off from the outer surface 81a due to a difference in thermal expansion between the fuse pattern 140 and the insulating material 81 at a threshold temperature or higher. The fuse pattern 140 is configured to interrupt current between the power source P and the load when it is cut.

[0089] Therefore, for example, when an overcurrent occurs between the power supply P and the load, the temperature of the electronic board device 62 rises due to the electrical resistance of the first conductor pattern 122, the first via 123, the second conductor pattern 131, the second via 132, and the fuse pattern 140. When the temperature of the electronic board device 62 reaches or exceeds a threshold temperature, the fuse pattern 140 peels off from the outer surface 81a. The fuse pattern 140 can be more easily peeled off from the outer surface 81a than when the fuse pattern 140 is provided inside the insulating material 81. The portion of the fuse pattern 140 that has peeled off from the outer surface 81a has difficulty dissipating heat to the insulating material 81 by thermal conduction, and also to the first via 123 and the second via 132, resulting in a rapid temperature rise. The overheated fuse pattern 140 melts and interrupts the overcurrent between the power supply P and the load. That is, the fuse pattern 140 becomes more likely to melt when peeled off from the outer surface 81a. Therefore, the electronic board device 62 does not need to narrow the fuse pattern 140 for blowing, and can pass a large current between the power supply P and the load. Furthermore, other parts of the electronic board device 62 have a larger heat capacity than the fuse pattern 140 that has been peeled off from the outer surface 81a. Therefore, when the fuse pattern 140 blows, the temperature of the other parts of the electronic board device 62 is lower than the temperature of the fuse pattern 140. In other words, the electronic board device 62 can interrupt the overcurrent before the components around the fuse pattern 140 overheat due to the overcurrent. Furthermore, the first via 123 and the second via 132 restrain the conductor including the fuse pattern 140. Therefore, the conductor peels off from the outer surface 81a between the first via 123 and the second via 132. In other words, the electronic board device 62 can interrupt the overcurrent at the desired position (fuse pattern 140). Since the first via 123 and the second via 132 are conductors, they can prevent a reduction in the allowable current of the wiring between the power supply P and the load.

[0090] The inductor 72 has a first terminal 151 and a second terminal 152. The inductor 72 is disposed on the outer surface 81a. The fuse pattern 140 has a first wiring 141 and a second wiring 142. The first wiring 141 connects the first via 123 and the first terminal 151. The second wiring 142 connects the second via 132 and the second terminal 152. The first wiring 141 is configured to peel off from the outer surface 81a due to a difference in thermal expansion between the first wiring 141 and the insulating material 81 at a threshold temperature or higher. Thus, as an example, the inductor 72 restrains the conductor including the fuse pattern 140. Therefore, peeling of the conductor from the outer surface 81a occurs between the first via 123 and the inductor 72. In other words, the electronic board device 62 can interrupt overcurrent at a desired position.

[0091] The first wiring 141 is longer than the second wiring 142. Therefore, as an example, the portion of the first wiring 141 that is not restrained by the first via 123 and the inductor 72 and is therefore likely to peel off is set to be relatively long. Therefore, the first wiring 141 is likely to peel off from the outer surface 81a. In other words, the electronic board device 62 can more reliably fuse the first wiring 141 and can cut off the overcurrent at a desired position.

[0092] The insulating material 81 has a plurality of insulating layers 90 located between the outer surface 81a and the outer surface 81b. The first conductor pattern 122 includes at least two of the external patterns 125 and 126 and the internal pattern 127 connected to the first via 123. The external patterns 125 and 126 are provided on the outer surfaces 81a and 81b. The internal pattern 127 is provided between two adjacent ones of the plurality of insulating layers 90. The second conductor pattern 131 includes at least two of the external patterns 135 and 136 and the internal pattern 137 connected to the second via 132. The external patterns 135 and 136 are provided on the outer surfaces 81a and 81b. The internal pattern 137 is provided between two adjacent ones of the plurality of insulating layers 90. Therefore, for example, between the power supply P and the first via 123, a current can flow in parallel through at least two of the external pattern 125, the external pattern 126, and the internal pattern 127. Furthermore, between the load and the second via 132, a current can flow in parallel through at least two of the external pattern 135, the external pattern 136, and the internal pattern 137. Therefore, the electronic board device 62 can prevent, for example, the external pattern 125, the external pattern 126, the external pattern 135, and the external pattern 136 from rising to a threshold temperature, and thus can prevent the external pattern 125, the external pattern 126, the external pattern 135, and the external pattern 136 from peeling off from the insulating material 81. In other words, the electronic board device 62 can more reliably fuse the fuse pattern 140 and interrupt the overcurrent at the desired position. Furthermore, the electronic board device 62 can increase the allowable current in the first conductor pattern 122 and the second conductor pattern 131, allowing a large current to flow between the power supply P and the load.

[0093] The load is the motor 25. A fluid chamber 45 configured to store brake fluid is provided in the pressure regulator 26. The pressure regulator 26 is configured to change the pressure in the fluid chamber 45 by being driven by the motor 25. Therefore, as an example, the brake control device 11 can pass a large current between the power source P and the motor 25. Therefore, the brake control device 11 can be equipped with a high-output motor 25.

[0094] In the above embodiment, the fuse pattern 140 has the first wiring 141 and the second wiring 142, and the inductor 72 is connected to the first wiring 141 and the second wiring 142. However, the fuse pattern 140 may be a single wiring pattern without being connected to an electronic component such as the inductor 72. In this case, peeling occurs somewhere in the fuse pattern 140 between the first via 123 and the second via 132.

[0095] As an example, the electronic board device according to at least one embodiment described above includes an insulating material having a first outer surface and a second outer surface located opposite the first outer surface, a first conductor pattern provided in the insulating material, a first via penetrating the insulating material, connected to the first conductor pattern, and configured to be electrically connected to a power source through the first conductor pattern, a second conductor pattern provided in the insulating material, a second via penetrating the insulating material, connected to the second conductor pattern, and configured to be electrically connected to a load through the second conductor pattern, and a fuse pattern provided on the first outer surface, connected to the first via and the second via, configured to peel off from the first outer surface due to a difference in thermal expansion with the insulating material at a temperature equal to or higher than a threshold temperature, and configured to interrupt current between the power source and the load when blown. Therefore, for example, when an overcurrent occurs between the power supply and the load, the temperature of the electronic board device rises due to the electrical resistance of the first conductor pattern, the first via, the second conductor pattern, the second via, and the fuse pattern. When the temperature of the electronic board device exceeds a threshold temperature, the fuse pattern peels off from the first outer surface. The fuse pattern can be more easily peeled off from the first outer surface than when it is provided inside the insulating material. The portion of the fuse pattern that peels off from the first outer surface has difficulty dissipating heat to the insulating material by thermal conduction, and also to the first and second vias, causing the temperature to rise rapidly. The overheated fuse pattern melts and interrupts the overcurrent between the power supply and the load. That is, the fuse pattern is more likely to melt when peeled off from the first outer surface. Therefore, the electronic board device does not need to have a thin fuse pattern to melt, and can pass a large current between the power supply and the load. Furthermore, other portions of the electronic board device have a larger heat capacity than the fuse pattern that peels off from the first outer surface. Therefore, when the fuse pattern melts, the temperature of other parts of the electronic board device is lower than that of the fuse pattern. That is, the electronic board device can cut off the overcurrent before the components around the fuse pattern overheat. In addition, the first and second vias restrain the conductors including the fuse pattern.Therefore, the conductor peeling from the first outer surface occurs between the first via and the second via. That is, the electronic board device can interrupt the overcurrent at the desired position. Furthermore, because the first via and the second via are conductors, it is possible to prevent a reduction in the allowable current of the wiring between the power supply and the load.

[0096] As an example, the electronic board device further includes an electronic component having a first terminal and a second terminal and disposed on the first outer surface, and the fuse pattern includes a first wiring connecting the first via and the first terminal and a second wiring connecting the second via and the second terminal, the first wiring being configured to peel off from the first outer surface due to a difference in thermal expansion with the insulating material at temperatures above the threshold temperature. Thus, as an example, the electronic component restrains the conductor including the fuse pattern. Therefore, peeling of the conductor from the first outer surface occurs between the first via and the electronic component. In other words, the electronic board device can interrupt overcurrent at a desired location.

[0097] In the electronic substrate device, for example, the first wiring is longer than the second wiring. Therefore, for example, the portion of the first wiring that is not constrained by the first via and the electronic component is set to be relatively long. Therefore, the first wiring is easily peeled off from the first outer surface. In other words, the electronic substrate device can more reliably fuse the first wiring and interrupt the overcurrent at the desired position.

[0098] In the electronic board device, as an example, the insulating material includes multiple insulating layers positioned between the first outer surface and the second outer surface, the first conductive pattern includes at least two of a first external pattern provided on the first outer surface, a second external pattern provided on the second outer surface, and a first internal pattern provided between two adjacent ones of the multiple insulating layers, connected to the first via, and the second conductive pattern includes at least two of a third external pattern provided on the first outer surface, a fourth external pattern provided on the second outer surface, and a second internal pattern provided between two adjacent ones of the multiple insulating layers, connected to the second via. Thus, as an example, between a power source and the first via, current can flow in parallel through at least two of the first external pattern, the second external pattern, and the first internal pattern. Also, between a load and the second via, current can flow in parallel through at least two of the third external pattern, the fourth external pattern, and the second internal pattern. Therefore, the electronic board device can prevent the first, second, third, and fourth external patterns from rising to a threshold temperature, thereby preventing the first, second, third, and fourth external patterns from peeling off from the insulating material. In other words, the electronic board device can more reliably blow the fuse pattern and interrupt overcurrent at the desired location. Furthermore, the electronic board device can increase the allowable current in the first and second conductor patterns, allowing a large current to flow between the power supply and the load.

[0099] The brake control device according to at least one embodiment described above includes, for example, the electronic board device, the load having an actuator, and a pressure regulating device having a fluid chamber configured to store brake fluid and configured to change the pressure of the fluid chamber by being driven by the actuator. Therefore, for example, the brake control device can allow a large current to flow between a power source and the actuator. Therefore, the brake control device can include a high-output actuator.

[0100] While the embodiments of the present invention have been described above, the above-described embodiments and modifications are merely examples and are not intended to limit the scope of the invention. The above-described embodiments and modifications can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the configurations and shapes of each embodiment and each modification can be partially interchanged. [Explanation of symbols]

[0101] 11...Brake control device, 25...Motor (load, actuator), 26...Pressure adjustment device, 45...Liquid chamber, 62...Electronic board device, 72...Inductor (electronic component), 81...Insulating material, 81a...Outer surface (first outer surface), 81b...Outer surface (second outer surface), 90...Insulating layer, 122...First conductor pattern, 123...First via, 125...External pattern (first outer pattern), 126...External pattern (second outer pattern), 127...internal pattern (first internal pattern), 131...second conductor pattern, 132...second via, 135...external pattern (third external pattern), 136...external pattern (fourth external pattern), 137...internal pattern (second internal pattern), 140...fuse pattern, 141...first wiring, 142...second wiring, 151...first terminal, 152...second terminal, P...power supply.

Claims

1. an insulating material having a first outer surface and a second outer surface opposite the first outer surface; a first conductor pattern provided on the insulating material; a first via extending through the insulating material and connected to the first conductor pattern, the first via configured to be electrically connected to a power source through the first conductor pattern; a second conductor pattern provided on the insulating material; a second via extending through the insulating material and connected to the second conductor pattern, the second via configured to be electrically connected to a load through the second conductor pattern; a fuse pattern provided on the first outer surface, connected to the first via and the second via, configured to peel off from the first outer surface due to a difference in thermal expansion with the insulating material at a threshold temperature or higher, and configured to interrupt current between the power source and the load when blown; An electronic board device comprising:

2. an electronic component having a first terminal and a second terminal and disposed on the first outer surface; Further comprising: the fuse pattern has a first wiring connecting the first via and the first terminal, and a second wiring connecting the second via and the second terminal; the first wiring is configured to peel off from the first outer surface due to a difference in thermal expansion between the first wiring and the insulating material at a temperature equal to or higher than the threshold temperature; The electronic substrate device according to claim 1.

3. The first wiring is longer than the second wiring. The electronic substrate device according to claim 2.

4. the insulating material having a plurality of insulating layers positioned between the first outer surface and the second outer surface; the first conductor pattern includes at least two of a first outer pattern provided on the first outer surface, a second outer pattern provided on the second outer surface, and a first inner pattern provided between two adjacent ones of the plurality of insulating layers, the at least two being connected to the first via; the second conductor pattern includes at least two of a third outer pattern provided on the first outer surface, a fourth outer pattern provided on the second outer surface, and a second inner pattern provided between two adjacent ones of the plurality of insulating layers, the at least two being connected to the second via; The electronic substrate device according to claim 1.

5. an electronic substrate device according to any one of claims 1 to 4; the load having an actuator; a pressure adjusting device provided with a fluid chamber configured to store brake fluid, and configured to change the pressure of the fluid chamber by being driven by the actuator; A brake control device comprising:

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