JP2012164761A - Electronic control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic control device capable of preventing, even when a block wire is fused due to excess current, a melting conductor from adversely affecting another electronic component or circuit on a surface of a high-density board.SOLUTION: An electronic control device 20 in which a wire 26 connected after an electronic component 24 is mounted on a substrate 21 is connected to a block wire 30 for blocking connection by fusing in response to heat generation due to excess current includes attaching means 40 disposed on the substrate 21 closer to the block wire 30 than to a protection target electronic component 22 for attaching a melting conductor in order to protect from the melting conductor generated along with the fusion of the block wire 30, the protection target electronic component 22 mounted on the substrate 21 except for the electronic component 24 from which connection is blocked by the block wire 30.

Description

  The present invention relates to an electronic control device in which a cutoff wiring for overcurrent protection is provided on a substrate.

  In recent years, in electronic control devices that are densified by small components, the short-circuit current that occurs at the time of a short-circuit failure in the miniaturized components does not reach a large current, so a fuse provided in response to a failure related to the electronic control device It takes a long time to shut off, and in particular, a large fuse that protects a plurality of electronic control devices for the purpose of reducing costs by reducing the number of installed fuses requires a longer time to shut off. For this reason, problems such as an increase in the temperature of parts at the time of interruption and a long-time voltage drop in the power supply wiring or the like occur. On the other hand, common wiring such as power supply wiring (for example, battery path and ground path) that is shared by many circuits and components mounted with the advancement of electronic control and multi-functionality and supplies power necessary for operation, such as A relatively large current flows even during normal operation of the apparatus. For this reason, since the breaking current of the large fuse provided in the shared wiring path tends to be further increased, there is a concern that a sufficient breaking performance cannot be ensured by a short circuit failure of individual circuits or components. For example, in the case of an apparatus having not only a high environmental temperature but also a large number of mounting apparatuses, such as an electronic control apparatus for a vehicle, the above-described problem becomes significant.

  For this reason, as in the printed circuit board control device disclosed in Patent Document 1 below, a short-circuit failure is provided by providing a cut-off wiring in the power supply wiring path on each board and fusing the cut-off wiring when an overcurrent flows. Sometimes the power supply wiring path is interrupted for each substrate or device.

JP 2007-31467 A

  By the way, on a highly densified substrate surface, wiring such as lands on which electronic components are mounted and connected and a plurality of electronic components including the electronic components are arranged close to each other. For this reason, when high heat is generated in the interrupting wiring due to overcurrent, the high-temperature molten conductor generated by melting of the interrupting wiring breaks the protective layer covering the substrate surface and flows, so that adjacent electronic components Or the circuit may be adversely affected. Specifically, if the molten conductor may cause a short circuit in the high-density wiring, or if it adheres to the connection part of another electronic component and the board, comparison of the melting point used in the connection part Therefore, there is a problem that a low solder is melted to cause a problem in connection of other electronic components.

  The present invention has been made in order to solve the above-described problems, and the object of the present invention is to provide a molten conductor other than that in the case where the interrupting wiring is blown off by overcurrent on the substrate surface having a high density. An object of the present invention is to provide an electronic control device that can avoid adversely affecting electronic components and circuits.

  In order to achieve the above object, in the electronic control device according to claim 1, the electronic component is mounted on the board and connected to the wiring connected to the wiring in response to heat generated by overcurrent. An electronic control device to which a cut-off wiring that cuts off the connection is connected, wherein the electronic component to be protected and the circuit mounted on the substrate other than the electronic components that are cut off by fusing of the cut-off wiring In order to protect from the molten conductor generated by fusing, it is provided on the substrate closer to the cutoff wiring than the electronic component and circuit to be protected, and has an attaching means for adhering the molten conductor Features.

  According to a second aspect of the present invention, in the electronic control device according to the first aspect, the adhering means is disposed on both sides of the cutoff wiring so as to face each other with the cutoff wiring interposed therebetween. Features.

  According to a third aspect of the present invention, in the electronic control device according to the second aspect, one of the adhering means disposed on both sides of the interrupting wiring is disposed adjacent to one end of the interrupting wiring. The other of the adhering means is arranged close to the other end of the blocking wiring.

  According to a fourth aspect of the present invention, in the electronic control device according to any one of the first to third aspects, the attachment means is an attachment wiring formed on the substrate, and protects the surface of the substrate. The layer is provided with an opening for exposing the wiring for adhesion.

  According to a fifth aspect of the present invention, in the electronic control device according to the fourth aspect, the adhesion wiring is coated with a metal having a melting point lower than that of the blocking wiring.

  According to a sixth aspect of the present invention, in the electronic control device according to the fifth aspect, solder is applied to the adhesion wiring as the metal.

According to a seventh aspect of the present invention, in the electronic control device according to any of the fourth to sixth aspects, the blocking wiring and the attachment wiring are provided on the same plane.
It is provided by removing the protective layer between the cut-off wiring and the adhesion wiring, and further includes a guide path for guiding the molten conductor to the adhesion wiring.

  According to an eighth aspect of the present invention, in the electronic control device according to any one of the fourth to sixth aspects, the substrate is provided with a recess, and the adhesion wiring is provided in the recess. It is characterized by that.

  According to a ninth aspect of the present invention, in the electronic control device according to any one of the eighth aspect, the substrate is configured by a multilayer substrate, and the adhesion wiring is a wiring provided on an inner layer side of the multilayer substrate. And the multilayer board is provided with a hole for exposing the wiring for adhesion.

  According to a tenth aspect of the present invention, in the electronic control device according to the ninth aspect, an interlayer connection portion is formed as the hole in the multilayer substrate, and the adhesion wiring is an inner peripheral surface of the interlayer connection portion. Is also provided.

  An eleventh aspect of the invention is the electronic control device according to any one of the fourth to tenth aspects, wherein the electronic control device is provided adjacent to the attachment wiring at least on the electronic component side and on the opposite side to the electronic component. The electronic control device according to claim 4, further comprising a convex portion.

  The invention of claim 12 is the electronic control device according to any one of claims 1 to 11, wherein a plurality of electronic components including the electronic component are connected to the substrate and shared wiring is used. A power supply wiring is provided.

  According to a thirteenth aspect of the present invention, in the electronic control device according to the twelfth aspect of the present invention, the substrate is provided with a common wiring as a power supply wiring to which a plurality of electronic components are connected, and the power supply wiring It is connected to a power supply that supplies power to another device different from the control device, and a common fuse for protecting the electronic control device and the other device is provided on a power supply path from the power supply. It is characterized by.

  According to the first aspect of the present invention, when the interrupting wiring expands and bursts due to overcurrent and melts, the high-temperature molten conductor generated in association with the circuit board comes close to the interrupting wiring when attempting to flow on the surface of the substrate. Adhering to the adhering means arranged in the. The molten conductor stays in a state of adhering to the adhering means, loses fluidity by being cured with heat dissipation, and is held on the adhering means. Therefore, it is possible to prevent the high-temperature molten conductor from causing problems in the connection of the electronic components to be protected or short-circuiting the circuit, and the molten conductor has an adverse effect on the electronic components and circuits to be protected that should be protected from the molten conductor. Can be avoided.

  According to the second aspect of the present invention, the molten conductor generated as the breaking wiring is fused adheres to one or both of the adhering means disposed on both sides of the breaking wiring so as to face each other. In this way, by arranging the adhesion wiring on both sides of the interrupting wiring and blocking the flow path of the molten conductor more widely, the molten conductor is more reliably adhered even when it is difficult to predict the flow direction of the molten conductor. It is possible to more reliably avoid the molten conductor from adversely affecting the electronic components and circuits to be protected.

  In the invention of claim 3, the molten conductor is attached to at least one of the adhering means arranged close to one end of the interrupting wiring and the adhering means arranged adjacent to the other end of the interrupting wiring. ,Adhere to. If the molten conductor tries to flow unevenly on either side of the attachment means arranged on both sides of the cut-off wiring, the wiring to which the electronic components are connected, the wiring connected to the cut-off wiring on the opposite side of this wiring, etc. There is a possibility that the molten conductor may be connected to the connection object on the adhering means and short-circuited again.

  On the other hand, one of the adhering means on both sides of the cutoff wiring is arranged close to one end of the cutoff wiring, so that the electronic component is connected to the other end. A wider gap is ensured between the wiring to be connected and one of the connection targets. Similarly, a wider gap is secured between the other of the adhering means and one end of the cutoff wiring, that is, between the wiring and the other connection target. As a result, even when the molten conductor tends to flow to either side of the attachment means, the gap is secured between the wiring or the connection object, so that the molten conductor is again on the attachment means, It is possible to avoid causing a short circuit.

  In the invention of claim 4, the molten conductor adheres to the adhesion wiring exposed from the opening provided in the protective layer. As described above, even when the substrate surface is covered with the protective layer, by exposing the adhesion wiring in advance, it is possible to reliably adhere the molten conductor that is to flow on the adhesion wiring.

  In the invention of claim 5, when the molten conductor adheres to the attachment wiring, the metal having a lower melting point than the applied molten conductor is melted by the high-temperature molten conductor and mixed with the molten conductor. As described above, the low melting point metal applied can improve the adhesion by the wiring for adhesion, and the molten conductor can be reliably adhered and retained.

  In the invention of claim 6, when the molten conductor adheres to the adhesion wiring, the applied solder is melted by the high-temperature molten conductor and mixed with the molten conductor, so that the molten conductor adheres to the adhesion wiring. . Thus, by applying a solder having a relatively low melting point in advance, the molten conductor can be reliably attached when the molten conductor is about to flow on the attachment wiring.

  In the invention of claim 7, the molten conductor generated along with the melting of the cutoff wiring is introduced into the induction path provided by removing the protective layer, and is applied to the adhesion wiring provided on the same plane as the cutoff wiring. It adheres to the wiring for adhesion by being guided toward. As described above, by providing the guide path between the cutoff wiring and the attachment wiring, it is possible to smoothly flow to the attachment wiring, so that the molten conductor can be reliably attached to the attachment wiring.

  In the invention according to claim 8, the molten conductor falls into the concave portion provided in the substrate, and thereby adheres to the attachment wiring provided therein. That is, since the molten conductor can be adhered while confined in the recess, the molten conductor can be more reliably retained on the adhesion wiring.

  According to the ninth aspect of the present invention, the molten conductor falls into a hole provided in the multilayer substrate, thereby being confined in the hole, and in this state, adheres to the adhesion wiring provided on the inner layer side of the multilayer substrate. Therefore, the molten conductor can be more reliably retained on the adhered wiring in the hole.

  In the invention of claim 10, since not only the bottom of the interlayer connection part but also the wall surface in the interlayer connection part can be used as the adhesion wiring, the molten conductor that has fallen into the interlayer connection part can be more reliably attached and retained. it can.

  In the eleventh aspect of the invention, the molten conductor is prevented from flowing to the portion other than the attachment wiring by the convex portions provided so as to be adjacent to the attachment wiring at least on the electronic component side and the opposite side. Adhere to. In this way, by providing projections on the electronic component side and the opposite side of the wiring for adhesion, and using it as a wall for the molten conductor, even if the molten conductor tries to flow other than the adhesion wiring, the above-mentioned short circuit is prevented again. However, the molten conductor can be reliably retained on the adhesion wiring.

  In the twelfth aspect of the invention, since the common wiring is a power supply wiring, a large current flows, and thus the above-described cutoff wiring is provided between the power supply wiring formed with a relatively wide wiring width and the component mounting wiring. Even in this case, it is possible to suppress a drop in the breaking performance (a variation or an increase in breaking time and breaking current) due to the breaking wiring.

  In the invention of claim 13, the power supply wiring is connected to a power supply that supplies power to another device different from the electronic control device, and a common fuse for protecting the electronic control device and the other device is provided. , Provided on the power supply path from the power supply. As a result, even when the electronic control device provided with the interruption wiring is short-circuited or the like, the interruption wiring is blown out, so that the influence on the power supply to other devices can be eliminated.

It is a block diagram showing a schematic structure of a vehicle control system provided with a traction control device concerning a 1st embodiment of the present invention. It is explanatory drawing which shows the principal part of the traction control apparatus of FIG. It is sectional drawing by the cut surface equivalent to the AA line of FIG. It is explanatory drawing which shows the principal part of the traction control apparatus which concerns on the 1st modification of 1st Embodiment. It is explanatory drawing which shows the principal part of the traction control apparatus which concerns on the 2nd modification of 1st Embodiment. It is sectional drawing by the cut surface equivalent to the BB line of FIG. It is explanatory drawing which shows the principal part of the traction control apparatus which concerns on the 3rd modification of 1st Embodiment. It is sectional drawing by the cut surface equivalent to the CC line of FIG. It is explanatory drawing which shows the principal part of the traction control apparatus which concerns on the 4th modification of 1st Embodiment. It is explanatory drawing for demonstrating the detailed shape of the verification interruption | blocking wiring and the verification opening. It is a graph which shows the relationship between interruption | blocking current value and interruption | blocking time about the presence or absence of a verification opening. It is explanatory drawing which shows the principal part of the traction control apparatus which concerns on 2nd Embodiment. It is sectional drawing by the cut surface equivalent to the DD line | wire of FIG. It is sectional drawing by the cut surface equivalent to the DD line | wire of FIG. 12 at the time of applying the traction control apparatus which concerns on the modification of 2nd Embodiment. It is explanatory drawing which shows the principal part of the electronic control apparatus which concerns on 3rd Embodiment.

[First Embodiment]
Hereinafter, an electronic control device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration of a vehicle control system 11 including a traction control device 20 according to the first embodiment.
As shown in FIG. 1, the vehicle control system 11 includes a plurality of electronic control devices 12 such as an engine ECU, a brake ECU, a steering ECU, a body ECU, and a navigation device that control various devices mounted on the automobile 10. It is configured.

  In addition to the plurality of electronic control devices 12, the vehicle control system 11 is provided with a traction control device 20 to which the electronic control device according to the first embodiment is applied. The traction control device 20 is a device having an acceleration slip prevention function for preventing an acceleration slip of a drive wheel, and is a device that is relatively less important than other electronic control devices for main vehicle control such as travel control.

  The plurality of electronic control devices 12 including the traction control device 20 are electrically connected to a DC power source (hereinafter referred to as a battery 13) via either a fuse 14a or a fuse 14b used for overcurrent protection. Yes. As the fuse 14a and the fuse 14b, large fuses for 15A or 20A, for example, are employed because they are provided in a path for supplying electric power necessary for operation to many electronic control devices. Thereby, for example, when a malfunction occurs in any of the various electronic control devices 12 connected to the fuse 14a and an overcurrent exceeding a predetermined current value is generated, the fuse 14a is blown by the overcurrent, and the fuse The power supply via 14a is interrupted, and adverse effects on other electronic control devices 12 are prevented. In the present embodiment, each electronic control unit 12 is electrically connected to the battery 13 via either one of the two large fuses 14a and 14b. However, the present invention is not limited to this. Each may be electrically connected to the battery 13 via a fuse, or may be electrically connected to the battery 13 via any one of three or more fuses.

Next, the configuration of the traction control device 20 according to the first embodiment will be described with reference to FIGS. FIG. 2 is an explanatory diagram showing a main part of the traction control device 20 of FIG. FIG. 3 is a cross-sectional view taken along the line AA in FIG.
The traction control device 20 is configured such that a circuit board 21 (board) on which a plurality of electronic components 22 and the like for realizing the above-described acceleration slip prevention function are mounted with a high density is accommodated in a case (not shown). The circuit board 21 is electrically connected to an external device or other electronic control device 12 via a connector or the like not shown in the figure, and accelerates the driving wheel according to a predetermined signal input from the outside. Perform control to prevent.

  As shown in FIG. 2, on the surface of the circuit board 21, a large number of electronic components including a ceramic capacitor 24 (electronic component) and an electronic component 22 (electronic component to be protected) provided in the vicinity thereof, and a power wiring 23 In addition, a large number of wirings such as the wiring 27 are densely arranged, and various circuits are constituted by these. Many circuits and components (not shown) are connected to the power supply wiring 23, and the power supply wiring 23 functions as a shared wiring shared by them, and power from the battery 13 is supplied to these circuits and Supply parts.

  As shown in FIG. 3, the circuit board 21 is configured by laminating a plurality of insulating layers 21a and conductor layers. As the insulating layer 21a, a glass woven fabric impregnated with an epoxy resin is used, and the conductor layer is made of a conductive material such as copper as wiring constituting a part of various circuits. . Various wirings on the substrate surface such as the power supply wiring 23 and the wiring 27 described above are formed as a part of the conductor layer. The surface of the circuit board 21 is covered and protected by a solder resist 28 (protective layer).

  The ceramic capacitor 24 is surface-mounted on the circuit board 21, and the external electrode 24 a of the ceramic capacitor 24 is connected to a land 26 provided as a part of the wiring of the circuit board 21 via the solder 25. In order to improve the temperature characteristics and frequency characteristics and realize a small capacity and a large capacity, the ceramic capacitor 24 is configured by stacking and integrating, for example, a barium titanate-based high dielectric constant ceramic dielectric and internal electrodes in layers. ing. The electronic component 22 is also surface-mounted on the circuit board 21 by being connected to the land 26 a connected to the wiring 27 via the solder 25.

  A cut-off wiring 30 is disposed between one land 26 of the ceramic capacitor 24 and the power supply wiring 23. The cutoff wiring 30 is a wiring that exhibits an overcurrent protection function by fusing in response to heat generated by an overcurrent, and cuts off an electrical connection through the cutoff wiring 30. Thereby, the overcurrent protection according to the board | substrate is realizable.

  Further, the cutoff wiring 30 is set so that the wiring width (the width of the wiring orthogonal to the current direction on the substrate surface) is sufficiently smaller than the wiring width of the power supply wiring 23. Specifically, for example, the wiring width of the cutoff wiring 30 is set to about 0.2 to 0.3 mm, and the wiring width of the power supply wiring 23 is set to about 2 mm.

  The cut-off wiring 30 is electrically connected to the power supply wiring 23 through one side connection wiring 30a at one end and is electrically connected to the land 26 through the other side connection wiring 30b at the other end. Yes. The one-side connection wiring 30 a and the other-side connection wiring 30 b are formed of the same conductive material such as copper as the cutoff wiring 30 and the power supply wiring 23 so that the conductor volume is larger than that of the cutoff wiring 30.

  Specifically, the one-side connection wiring 30a is formed so that the side edges on both sides are smoothly continuous with the side edges on both sides of the cutoff wiring 30 and spread in an arc shape toward the power supply wiring 23 to be connected. Has been. Further, the other-side connection wiring 30b is formed so that the side edges on both sides are smoothly continuous with the side edges on both sides of the cutoff wiring 30 and spread in an arc shape toward the land 26 to be connected. That is, the one-side connection wiring 30 a is formed so that the wiring width becomes wider toward the power supply wiring 23, so that the cross-sectional area at the connection portion with the cutoff wiring 30 is cut off at the connection portion with the power supply wiring 23. It is comprised so that it may become smaller than an area.

  Adhesion wiring 40 (attachment means) is provided in the vicinity of the blocking wiring 30. The adhering wiring 40 is arranged at a position closer to the blocking wiring 30 than the other electronic components including the electronic component 22 in the approximate center between the power supply wiring 23 and the land 26. Further, the adhesion wiring 40 is provided on both sides of the cutoff wiring 30 so as to face each other with the cutoff wiring 30 in between.

  The adhesion wiring 40 is made of copper like the cutoff wiring 30 and the power supply wiring 23, and is provided on the surface of the insulating layer 21 a of the circuit board 21. Further, a portion of the outer edge of the attachment wiring 40 that faces the blocking wiring 30 has a convex curved shape toward the blocking wiring 30.

  In addition, openings 28 a are provided in portions corresponding to both sides of the blocking wiring 30 of the solder resist 28. Each opening 28a is provided in the same shape and position as the attachment wiring 40, whereby the attachment wiring 40 is exposed. In addition, solder 40 a is applied to the entire surface of the exposed adhesion wiring 40 as a metal having a melting point lower than that of the blocking wiring 30.

  In the traction control device 20 configured as described above, for example, when the ceramic capacitor 24 is short-circuited due to damage or the like and an overcurrent flows through the cutoff wiring 30, the cutoff wiring 30 generates heat according to the overcurrent. When this heat generation exceeds a predetermined temperature, the cut-off wiring 30 is melted and the electrical connection via the cut-off wiring 30 is cut off. As a result, other electronic components connected to the power supply wiring 23 are protected from the overcurrent. Further, since the current at the time of interruption is not so large as to cut off the fuse 14a, damage to the traction control device 20 does not affect other electronic control devices 12 that are supplied with power through the fuse 14a. . Furthermore, the time from the occurrence of an overcurrent to the blowout of the interrupt wiring 30 is about several milliseconds (milliseconds), and the blowout time of the large fuses 14a, 14b, etc. is usually about 0.02S (seconds). Therefore, overcurrent protection can be suitably implemented even with an electronic control device or electronic component that can improve the processing speed.

  Further, in response to the heat generated by the overcurrent, the molten conductor is generated as the breaking wiring 30 is blown out due to expansion or rupture. When the generated molten conductor breaks the solder resist 28 and tries to flow on the surface thereof, the molten conductor adheres to the adhesion wiring 40 when it tries to pass over the adhesion wiring 40 arranged close to the blocking wiring 30. By doing so, the flow of the molten conductor is prevented.

  Specifically, when the molten conductor comes into contact with the solder 40a applied to the adhesion wiring 40, the solder 40a is melted by the high-temperature molten conductor and mixed with the molten conductor, so that the molten conductor is placed on the adhesion wiring 40. Let it stay. Then, the molten conductor gradually loses its fluidity by being hardened with heat dissipation, and is held in place to prevent the molten conductor from flowing on the adhesion wiring 40.

As described above, according to the traction control device 20 according to the present embodiment,
The adhering wiring 40 is arranged so as to face each other on both sides of the interrupting wiring 30 and more widely blocks the flow path of the molten conductor, so that the molten conductor can be more reliably secured even when the flow direction of the molten conductor is difficult to predict Can be attached to the attachment wiring 40. As a result, the molten conductor flows and contacts the connection part of the electronic component 22 and the land 26a, the wiring 27, etc., thereby causing a problem in the connection of the electronic component 22 or short-circuiting the circuit. Can be prevented, and adverse effects on the electronic component 22 and the circuit to be protected from the molten conductor can be avoided.

  Moreover, since the opening 28a is provided in the solder resist 28, the adhesion wiring 40 is exposed in advance, and the solder 40a is applied to the adhesion wiring 40, the molten conductor flows on the adhesion wiring 40. Sometimes the molten conductor can be reliably attached.

  Moreover, the power supply wiring 23 is connected to each connector via the electric wire from the battery 13 that supplies electric power to another electronic control device 12 different from the traction control device 20, and the traction control device 20 and a plurality of other control devices 20. Since the common fuse 14a for protecting the electronic control device 12 is provided on the power supply path from the battery 13, even if the traction control device 20 provided with the cutoff wiring 30 is short-circuited or the like. Since the cut-off wiring 30 is fused, the influence on the power supply to the other electronic control device 12 can be eliminated.

  Further, since heat generated in the cut-off wiring 30 due to overcurrent is transmitted to the power supply wiring 23 and the land 26 through the one side connection wiring 30a and the other side connection wiring 30b, it is compared with the case where it is directly transmitted to the power supply wiring 23 and land 26. Thus, heat is held in the one side connection wiring 30a and the other side connection wiring 30b, and diffusion of heat to the power supply wiring 23 and the land 26 is suppressed. Thereby, since the dispersion | variation in the temperature rise in the interruption | blocking wiring 30 is suppressed, the fall of the interruption | blocking performance by the interruption | blocking wiring 30 provided in the board | substrate surface densified can be suppressed. In particular, the heat generated in the cut-off wiring 30 due to the overcurrent is diffused in the other-side connection wiring 30b and transmitted to the land 26, so that the local temperature rise in the land 26 is alleviated. Thereby, melting of the solder 25 due to heat from the interruption wiring 30 can be suppressed. Moreover, since the one side connection wiring 30a and the other side connection wiring 30b have a conductor volume larger than that of the cutoff wiring 30, heat from the cutoff wiring 30 can be suitably stored.

  Further, since the side edges of the cutoff wiring 30 and both connection wirings 30a, 30b are gently continuous, when the wirings 30, 30a, 30b are formed using an etching solution, both the side edges of the cutoff wiring 30 and the both sides The etching solution can easily flow uniformly at the connection portions with the side edges of the connection wirings 30a and 30b. Thereby, the retention of the etching solution at the connection portion is suppressed, and the variation in the wiring width of the cutoff wiring 30 is suppressed. Therefore, it is possible to suppress a reduction in the cutoff performance due to the cutoff wiring 30 provided on the substrate surface.

  In the present embodiment, the electronic component 22 and the wiring 27 have been described as examples of the electronic component to be protected and the circuit to be protected from the molten conductor, but all the electronic components mounted on the circuit board 21 other than the ceramic capacitor 24 are described. It goes without saying that the circuit is protected from the molten conductor as the electronic component and circuit to be protected.

FIG. 4 is an explanatory diagram showing a main part of the traction control device 20a according to the first modification of the first embodiment described above.
As shown in FIG. 4, in this modification, the one adhering wiring 40 and the opening 28 a are arranged close to the end of the blocking wiring 30 on the land 26 side, so that the gap between the land 26 and the land 26 is increased. On the other hand, a gap larger than that between the power supply wiring 23 and the land 26 is secured. Further, the other adhering wiring 40 and the opening 28a are arranged close to the end of the cutoff wiring 30 on the power supply wiring 23 side, thereby narrowing the gap between the power supply wiring 23 and the land 26. A gap larger than that between the power supply wiring 23 is secured between them.

  Therefore, even when the molten conductor generated by fusing the cut-off wiring 30 flows unevenly toward one of the adhesion wirings 40, a relatively wide space is provided between the land 26 or the power supply wiring 23. It stays on the wiring 40 for adhesion. As a result, it is possible to avoid another short circuit due to the molten conductor connecting between the land 26 and the power supply wiring 23 on the adhesion wiring 40.

FIG. 5 is an explanatory view showing a main part of a traction control device 20b according to a second modification of the first embodiment, and FIG. 6 is a cross-sectional view taken along the line BB in FIG.
As shown in FIG. 5, in this modification, a guide path 28 b is provided between the blocking wiring 30 and the adhesion wiring 40. The guide path 28b is provided by removing the solder resist 28 between the adhering wirings 40, 40, so that not only the adhering wiring 40 but also the center of the blocking wiring 30 as shown in FIG. And the insulating layer 21 a between the adhesion wiring 40 and the blocking wiring 30 is exposed.

  Therefore, the molten conductor in which the interruption wiring 30 is melted is introduced into the guide path 28b adjacent to the interruption wiring 30 and is guided toward the adhesion wiring 40 provided on the same plane as the interruption wiring 30 to be attached. It adheres to the wiring 40 for use. As described above, since the molten conductor can smoothly flow to the adhesion wiring 40, the molten conductor can be reliably adhered to the adhesion wiring 40.

  FIG. 7 is an explanatory view showing a main part of a traction control device 20c according to a third modification of the first embodiment, and FIG. 8 is a cross-sectional view taken along the line CC in FIG.

  As shown in FIG. 7, a guide path 28 b similar to that in the second modification described above is provided between the blocking wiring 30 and the adhesion wiring 40. Further, convex portions 28 c and 28 c are formed adjacent to the attachment wiring 40 in the gap between the attachment wiring 40 and the land 26 and the power supply wiring 23. As shown in FIG. 8, the convex portion 28 c is formed by raising the solder resist 28 more than other portions by partially subjecting the solder resist 28 to multiple processing.

  Therefore, the molten conductor is introduced into the induction path 28b and guided to the adhesion wiring 40, and the flow from the other than the adhesion wiring 40 is prevented by the convex portions 28c and 28c on both sides of the adhesion wiring 40, It adheres to the wiring 40 for adhesion. Thus, by providing the convex portion 28c as a wall, the molten conductor can be surely placed on the adhesion wiring 40 while avoiding the above-mentioned short circuit even if the molten conductor tries to flow other than the adhesion wiring 40. Can stay.

  Note that, instead of the convex portion 28c by the multiple processing of the solder resist 28 described above, the convex portion 28c may be formed by performing silk screen printing using, for example, heat-resistant ink. Further, except for the cut-off wiring 30 side, the protruding portion 28c may be provided partially or so as to surround the adhesion wiring 40 depending on the flow direction of the molten conductor.

  FIG. 9 is an explanatory diagram showing a main part of a traction control device 20d according to a fourth modification of the first embodiment.

  As shown in FIG. 9, the solder resist 28 is formed with a rectangular opening 28e for exposing at least a part of the blocking wiring 30 to the outside. Specifically, the opening 28e is formed so as to expose a portion near the center of the entire length, which is the portion that generates the most heat in the cutoff wiring 30, to the outside.

  Here, the reason why the opening 28e is formed will be described with reference to FIGS. FIG. 10 is an explanatory diagram for explaining the detailed shapes of the verification cutoff wiring 101 and the verification opening 102. FIG. 11 is a graph showing the relationship between the cutoff current value I and the cutoff time t with or without the verification opening 102.

  A predetermined current is passed through the verification cutoff wiring 101 partially exposed through the verification opening 102 having the dimensions shown in FIG. 10, and the cutoff current value I when the verification cutoff wiring 101 is melted and the verification cutoff. The fusing time t until the wiring 101 is melted is measured. Further, the cutoff current value I and the fusing time t when a predetermined current is passed through the verification cutoff wiring 101 in which the verification opening 102 is not formed are measured. Here, the verification cutoff wiring 101 has its entire length L1 set to 2.85 mm and its width W1 set to 0.25 mm. The verification opening 102 has an opening length L2 parallel to L1 set to 0.6 mm and an opening width W2 set to 0.25 mm. In FIG. 10, the opening width W2 is shown to be longer than the width W1 for convenience of explanation.

  The relationship between the cut-off current value I and the cut-off time t measured as described above is shown in the graph of FIG. Here, a thick solid line S1 shown in FIG. 11 shows a relationship between the cutoff current value I and the fusing time t in the verification cutoff wiring 101 partially exposed by the verification opening 102, and a thick broken line centering on the thick solid line S1. The range surrounded by indicates the variation range of the cutoff time t in the cutoff current value I. A thin solid line S2 shown in FIG. 11 indicates the relationship between the cutoff current value I and the fusing time t in the verification cutoff wiring 101 in which the verification opening 102 is not formed, and is surrounded by a thin broken line with the fine solid line S2 as the center. The range indicates a range of variation in the cutoff time t in the cutoff current value I.

  As can be seen from FIG. 11, the fusing time t is shortened by forming the verification opening 102 at the same breaking current value. Further, the variation in the fusing time t is small at the same breaking current value. On the other hand, in the verification cutoff wiring 101 in which the verification opening 102 is not formed, the fusing time t is longer in each overcurrent region and the fusing time t varies more than in the case where the verification opening 102 is formed. Has occurred. This is because the molten conductor generated by fusing the verification cutoff wiring 101 flows out of the verification opening 102 and does not easily stay at the position of the verification cutoff wiring 101 before the fusing.

  For this reason, by exposing at least a part of the cut-off wiring 30 through the opening 28e, the fusing time t is shortened and a protective action can be obtained at an early stage, and the temperature rise of the parts to be protected can be suppressed. . Furthermore, it is possible to greatly reduce the influence time of the voltage drop on the power supply wiring 23 when the cutoff wiring 30 is shut off. Further, by reducing the variation in the fusing time t, it is possible to adopt a capacitor having a smaller capacity, such as a stabilizing capacitor (power stabilization means) that takes into account the fusing time of the cutoff wiring 30 in each device or circuit, Cost reduction and size reduction can be achieved. Furthermore, since the fusing time t can be reduced even in the rated current range, the degree of freedom in circuit design can be improved.

  In addition, a thermal diffusion wiring 70 for diffusing heat generated by overcurrent in the cutoff wiring 30 is formed between the cutoff wiring 30 and the electronic component 22. The thermal diffusion wiring 70 is made of a conductive material such as copper, like the wiring 27, and extends so as to partition the cutoff wiring 30 and the electronic component 22.

  Therefore, in the present modification, the molten conductor generated by fusing the cutoff wiring 30 flows out from the opening 28e. This makes it difficult for the molten conductor to stay at the position of the interrupting wiring 30 before fusing, thereby suppressing variations in fusing position and fusing time due to the residence of the molten conductor, and suppressing the deterioration of the interruption performance due to the interrupting wiring 30. can do.

  Furthermore, since the opening 28e is formed so as to expose the most heat-generating part of the cutoff wiring 30, the opening 28e is provided corresponding to the part of the cutoff wiring 30 that is likely to be blown, and the molten conductor is blown. It is possible to reliably suppress staying at the position of the previous interrupting wiring 30 and to reliably suppress a decrease in the interrupting performance due to the interrupting wiring 30.

  Further, when the heat generated in the interruption wiring 30 due to an overcurrent is transmitted to the surroundings, the heat diffusion to the electronic component 22 to be protected from the heat is suppressed by being diffused by the heat diffusion wiring 70. Thereby, the normal operation of the electronic component 22 can be maintained.

[Second Embodiment]
Next, a traction control device according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 12 is an explanatory diagram showing a main part of the traction control device 20e according to the second embodiment. 13 is a cross-sectional view taken along the line D-D in FIG.

  The second embodiment is mainly different from the first embodiment described above in that, in the traction control device 20e, an attachment wiring 41 having a different configuration is employed instead of the attachment wiring 40. For this reason, components substantially the same as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and differences from the first embodiment will be mainly described.

  As shown in FIG. 13, the circuit board 21 of the present embodiment is formed of a multilayer substrate, and is formed by laminating a plurality of insulating layers 21a and conductor layers. For the sake of convenience, the following description will be given assuming that the front surface side of the circuit board 21 on which the ceramic capacitor 24 and the cutoff wiring 30 are disposed is “upper” and the rear surface side is “lower”.

  The adhesion wiring 41 is provided between the uppermost insulating layer 21a and the insulating layer 21a immediately below the uppermost insulating layer 21a. This adhesion wiring 41 is provided as a part of the conductor layer, and is made of copper like the blocking wiring 30 and the like. In addition, the uppermost insulating layer 21 a is provided with two holes 21 b and 21 b on both sides of the cutoff wiring 30 in a region surrounded by the cutoff wiring 30, the land 26 and the power supply wiring 23. The solder resist 28 at the same location as the hole 21b is provided with a circular opening 28d, and the adhesion wiring 41 is exposed through the hole 21b and the opening 28d. That is, the adhesion wiring 41 is disposed at the bottom of the hole 21b.

  In the traction control device 20e configured as described above, even if the molten conductor is about to flow, the molten conductor is trapped inside the holes 21b and 21b provided close to the blocking wiring 30. In this state, since it adheres to the adhesion wiring 41 at the bottom of the hole 21b, the molten conductor can be reliably retained on the adhesion wiring 41 and held in the hole 21b.

  FIG. 14 is a cross-sectional view showing a traction control device 20f according to a modification of the second embodiment. This cross-sectional view is a cross-sectional view corresponding to the line DD in FIG. 12 when the present modification is applied to the second embodiment described above.

  In the second embodiment described above, the adhesion wiring 41 is exposed by simply providing the hole 21b in the uppermost insulating layer 21a, whereas in the present modification, for example, the upper two insulating layers 21a, The interlayer connection portion 21c is provided in 21a, and the adhesion wiring 42 is formed on the entire inner peripheral surface and bottom surface inside. Thereby, not only the bottom surface in the interlayer connection portion 21c but also the wall surface can be used as the wiring for adhesion, so that the molten conductor that has fallen into the interlayer connection portion 21c can be more reliably adhered and held in the interlayer connection portion 21c. Can do.

[Third Embodiment]
Next, an electronic control unit according to a third embodiment of the present invention will be described with reference to FIG. FIG. 15 is an explanatory diagram illustrating a main part of the electronic control device 110 according to the third embodiment.
In the electronic control device 110 according to the third embodiment, a circuit block 130 in which the functions of the traction control device 20 according to the first embodiment are formed into circuit blocks on the same substrate 120, and further functions are circuit blocks. The circuit blocks 140 and 150 are arranged. The other function is a function that is more important than the function of the circuit block 130, for example, a function corresponding to the engine ECU or a function corresponding to the brake ECU. The circuit block 140 is connected to the engine ECU. Corresponding functions are configured as circuit blocks, and the circuit block 150 is configured by converting functions corresponding to the brake ECU into circuit blocks.

  As shown in FIG. 15, each circuit block 130, 140, 150 is electrically connected to a power supply wiring 23 that supplies power from the battery 13 via a connector 121 via branch wirings 131, 141, 151, respectively. It is connected. The interruption wiring 30 described above is arranged on the branch wiring 131 of the circuit block 130 so as to function as overcurrent protection for the circuit block 130. On the power supply wiring 23, a cutoff wiring 122 that functions as overcurrent protection for the substrate 120 is provided. That is, on the substrate 120, two blocking wires are provided, that is, a blocking wire 122 that protects the substrate 120 including all the circuit blocks 130 to 150 and a blocking wire 30 that protects the circuit block 130.

  As a result, an overcurrent occurs due to a short circuit failure or the like in the circuit block 130 in which the interruption wiring 30 is provided. Even when the interruption wiring 30 is melted, the other circuit blocks 140 and 150 are connected via the branch wirings 141 and 151. Since the connection with the power supply wiring 23 is maintained, it is possible to stop the function of only the circuit block 130 having the blown cutoff wiring 30 and continue the functions of the other circuit blocks 140 and 150. In particular, since the function of the circuit block 130 is less important than the other circuit blocks 140 and 150, the function stop of the less important circuit block 130 affects the functions of the circuit blocks 140 and 150 having higher importance. Can be suppressed. Further, even when an overcurrent occurs in the circuit blocks 140 and 150 in which the cutoff wiring 30 is not provided due to a short circuit failure or the like, the cutoff wiring 122 is melted by the overcurrent flowing through the power supply wiring 23, so that each circuit block 130 or 140. , 150 stops, it is possible to suppress the generated overcurrent from flowing to other circuit blocks.

In particular, by forming the cut-off wiring 30 so that the current value at the time of cut-off with respect to the cut-off wiring 122 is reduced, an overcurrent is caused in the circuit block 130 provided with the cut-off wiring 30 due to a short circuit failure or the like. When this occurs, the interruption wiring 30 is surely fused faster than the interruption wiring 122. Thereby, the influence on the other circuit blocks 140 and 150 can be reliably suppressed.
In addition, the structure which provides two interruption | blocking wiring on one board | substrate in this embodiment may be employ | adopted for other embodiment and a modification.

In addition, this invention is not limited to the said embodiment and its modification, You may actualize as follows.
(1) The attachment wirings 41 and 42 of the second embodiment and the modified example thereof are replaced with the land 26 to which the ceramic capacitor 24 is connected and the power supply wiring 23 as in the first modification of the first embodiment. By arranging them closer to one, a wider gap may be secured between the other of the two 26, 23.
(2) The attachment wirings 40 to 42 described in the first and second embodiments described above and the traction control devices 20 and 20a to 20f of the modified examples are used for the body including the engine ECU, the brake ECU, and the steering ECU described above. In a plurality of electronic control devices 12 such as an ECU and a navigation device, the electronic control device 12 may be employed for protection from a molten conductor generated when the breaking wiring is blown.

DESCRIPTION OF SYMBOLS 10 ... Automobile 11 ... Vehicle control system 12 ... Electronic control unit 13 ... Battery (power supply)
14a, b ... fuse 20, 20a-20f ... traction control device (electronic control device)
21 ... Circuit board (board)
21a ... Insulating layer 21b ... Hole 21c ... Interlayer connection part 22 ... Electronic component 22a ... External electrode 23 ... Power supply wiring (common wiring)
24 ... Ceramic capacitors (electronic parts)
24a ... external electrode 25 ... solder 26, 26a ... land (wiring)
27 ... Wiring 28 ... Solder resist (protective layer)
28a, 28d-e ... opening 28b ... guide path 28c ... convex part 30 ... cut-off wiring 30a-b ... connection wiring 40-42 ... wiring for adhesion (attachment means)
40a ... solder (metal)
DESCRIPTION OF SYMBOLS 70 ... Thermal diffusion wiring 101 ... Verification cutoff wiring 102 ... Verification opening 110 ... Electronic control unit 122 ... Shutdown wiring 130, 140, 150 ... Circuit block

Claims (13)

An electronic control device in which a cut-off wiring that cuts off a connection by fusing in response to heat generated by an overcurrent is connected to a wiring that is mounted and connected to an electronic component on a board,
In order to protect the protection target electronic components and circuits mounted on the substrate other than the electronic component whose connection is cut off by the cutting of the cut-off wiring from the molten conductor generated by the cut-off of the cut-off wiring, the protection target An electronic control device, comprising: an adhering unit disposed on the substrate closer to the cut-off wiring than an electronic component and a circuit, and adhering the molten conductor.   2. The electronic control device according to claim 1, wherein the adhering means is disposed on both sides of the cutoff wiring so as to face each other with the cutoff wiring interposed therebetween.   One of the adhering means disposed on both sides of the blocking wiring is disposed in proximity to one end of the blocking wiring, and the other of the adhering means is the other end of the blocking wiring. The electronic control device according to claim 2, wherein the electronic control device is disposed adjacent to the electronic control device. The attachment means is an attachment wiring formed on the substrate,
The electronic control device according to any one of claims 1 to 3, wherein the protective layer covering the surface of the substrate is provided with an opening for exposing the wiring for adhesion.   The electronic control device according to claim 4, wherein a metal having a melting point lower than that of the blocking wiring is applied to the adhesion wiring.   6. The electronic control device according to claim 5, wherein solder is applied to the adhesion wiring as the metal. The blocking wiring and the adhesion wiring are provided on the same plane,
5. The apparatus according to claim 4, further comprising a guide path provided by removing the protective layer between the blocking wiring and the adhesion wiring and guiding the molten conductor to the adhesion wiring. The electronic control apparatus as described in any one of -6.   The electronic control device according to claim 4, wherein the substrate is provided with a recess, and the adhesion wiring is provided in the recess. The substrate comprises a multilayer substrate;
The adhesion wiring is a wiring provided on the inner layer side of the multilayer substrate,
9. The electronic control device according to claim 8, wherein the multilayer substrate is provided with a hole for exposing the adhesion wiring as the concave portion. In the multilayer substrate, an interlayer connection portion is formed as the hole,
The electronic control device according to claim 9, wherein the adhesion wiring is also provided on a wall surface in the interlayer connection portion.   11. The apparatus according to claim 4, further comprising a convex portion provided adjacent to at least the electronic component side and the opposite side of the electronic component with respect to the adhesion wiring. 11. The electronic control device described.   The power supply wiring is provided in the said board | substrate as a common wiring which a some electronic component including the said electronic component is connected and is shared, The Claim 1 characterized by the above-mentioned. Electronic control device. The power supply wiring is connected to a power supply that supplies power to another device different from the electronic control device,
The electronic control device according to claim 12, wherein a common fuse for protecting the electronic control device and the other device is provided on a power supply path from the power supply.

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