JP2013084987A - Manufacturing method of wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a wiring board capable of suppressing the degradation of cutoff performance by a cutoff wire provided on a board surface.SOLUTION: Etching resist, which is formed in a region other than a wiring pattern including a cutoff wire 30, a connection wire 40 on one side and a connection wire 50 on the other side, is removed to obtain a board provided with the remaining etching resist 29. The etching resist 29 having remained on the board is in such a shape that lateral edges on both sides of the etching resist 29 on a conductor layer corresponding to the connection wiring 40 on one side and the connection wiring 50 on the other side are smoothly continuous with lateral edges on both sides of the etching resist 29 on the conductor layer corresponding to the cutoff wire 30, while gradually spreading toward connection objects. The board is then dipped in an etchant.

Description

  The present invention relates to a method of manufacturing a wiring board in which a cut-off wiring for overcurrent protection is provided on the board.

  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, when a predetermined wiring pattern including a blocking wiring is formed on a high-density substrate surface, in general, a resist is formed by immersing in an etching solution after forming a resist on a non-etched surface of a conductor layer. The region not formed is etched to form the predetermined wiring pattern.

  At this time, since there is a region around the cutoff wiring in which the etching solution is difficult to flow uniformly due to the shape of the wiring pattern, the wiring width of the cutoff wiring may vary if etching does not proceed easily in that region. . On the other hand, since the etching solution that has flowed into the region as described above stays without flowing out suitably, even if etching proceeds more than necessary in that region, the wiring width of the cut-off wiring may vary. For this reason, there exists a problem that the interruption | blocking performance will fall because the position and cutting | disconnection timing at which the interruption | blocking wiring blows vary. In particular, in a connection portion where the interruption wiring is connected to other wiring, this problem becomes significant because the wiring width of the interruption wiring needs to be narrower than the wiring width of the other wiring.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method of manufacturing a wiring board that can suppress a decrease in the breaking performance due to the breaking wiring provided on the board surface. It is in.

  In order to achieve the above object, in the method for manufacturing a wiring board according to claim 1, the cut-off wiring that cuts off the connection with the connection target when fusing in response to heat generated by overcurrent is connected wiring. A method of manufacturing a wiring board formed on a substrate connected to the connection target via a first step of preparing a substrate provided with a conductor layer for constituting the blocking wiring and the connection wiring And a second step of forming an etching resist on the conductor layer, and removing the etching resist formed in a region different from the wiring pattern including the blocking wiring and the connection wiring in the etching resist, A side edge in the etching resist on the conductor layer corresponding to the connection wiring is a side edge in the etching resist on the conductor layer corresponding to the blocking wiring. The substrate is immersed in an etching solution for removing the conductive layer on which the etching resist is not formed, and a third step of leaving the etching resist so as to spread gradually and continuously toward the connection target. A fourth step and a fifth step of removing the etching resist from the substrate after the immersion.

  In the first aspect of the invention, the etching resist formed in a region different from the wiring pattern including the cutoff wiring and the connection wiring is removed, and the side edge in the etching resist on the conductor layer corresponding to the connection wiring corresponds to the cutoff wiring. The substrate on which the etching resist is left is soaked in the etching solution so as to be gradually continuous with the side edges of the etching resist on the conductor layer to be connected and gradually spread toward the connection target.

  As described above, since the side edges of the etching resist on the conductor layer corresponding to the blocking wiring and the etching resist on the conductor layer corresponding to the connection wiring are continuously continuous, the etching resist is not formed using the etching solution. When the conductor layer is removed, the etching solution easily flows uniformly at the connection portion between the side edge of the cutoff wiring and the side edge of the connection wiring. Thereby, the retention of the etching solution at the connection portion is suppressed, and the variation in the wiring width of the cutoff wiring is suppressed. Therefore, it is possible to suppress a reduction in the cutoff performance due to the cutoff wiring provided on the substrate surface.

It is a block diagram showing a schematic structure of a vehicle control system provided with a traction control device concerning a 1st embodiment. 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 3-3 line of FIG. It is explanatory drawing which expands and shows the interruption | blocking wiring vicinity of FIG. It is explanatory drawing for demonstrating the interruption | blocking wiring at the time of shaping | molding, and connection wiring. 6A is a cross-sectional view taken along the line 6A-6A in FIG. 5, and FIG. 6B is a cross-sectional view taken along the line 6B-6B in 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 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 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 2nd Embodiment. It is explanatory drawing which shows the principal part of the traction control apparatus which concerns on the 2nd modification of 2nd Embodiment. It is explanatory drawing which shows the principal part of the traction control apparatus which concerns on 3rd Embodiment. It is explanatory drawing which shows the principal part of the electronic control apparatus which concerns on 4th 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 14a The electric power supply via is cut off, 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 line 3-3 in FIG. FIG. 4 is an explanatory diagram showing an enlarged view of the vicinity of the cutoff wiring 30 in FIG. 2 and 4, for the sake of convenience, illustration of the solder resist 28 that is a protective layer for protecting the substrate surface is omitted.

  The traction control device 20 is configured such that a circuit board 21 on which a plurality of electronic components 22 for realizing the above-described accelerated slip prevention function are mounted with a high density is housed 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, power wirings 23 for supplying power from the battery 13 are electrically connected to the electronic components 22 on the circuit board 21. For this reason, the power supply wiring 23 functions as a shared wiring shared by the electronic components 22.

  As shown in FIGS. 2 and 3, a ceramic capacitor 24 is mounted on the circuit board 21 as one of the plurality of electronic components 22. In order to improve the temperature characteristic and the frequency characteristic and realize a small capacity and a large capacity, the ceramic capacitor 24 is formed by, for example, stacking and integrating a barium titanate-based high dielectric constant ceramic dielectric 24b and an internal electrode 24c in layers. It is configured.

  Between the land 26 to which the external electrode 24 a of the ceramic capacitor 24 is connected via the solder 25 and the power supply wiring 23, a cutoff wiring 30 is disposed. 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.

  Here, 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 cutoff wiring 30 is electrically connected to the power supply wiring 23 through one side connection wiring 40 at one end and is electrically connected to the land 26 through the other side connection wiring 50 at the other end. Yes. The one side connection wiring 40 and the other side connection wiring 50 are formed of a conductive material such as copper, which is the same as that of 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, as shown in FIG. 4, the one-side connection wiring 40 has a power supply that is a connection target because the side edges 41 and 42 on both sides are smoothly continuous with the side edges 31 and 32 on both sides of the cutoff wiring 30. It is formed so as to spread in an arc shape as it goes to the wiring 23. That is, the one-side connection wiring 40 is formed so that the wiring width becomes wider toward the power supply wiring 23 side, 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.

  Further, the other side connection wiring 50 is such that the side edges 51 and 52 on both sides are smoothly continuous with the side edges 31 and 32 on both sides of the cutoff wiring 30 and expands in an arc shape toward the land 26 to be connected. Is formed. That is, the other-side connection wiring 50 is formed so that the wiring width becomes wider toward the land 26 side, so that the cross-sectional area at the connection site with the cutoff wiring 30 is a connection site with the land 26 to be connected. It is comprised so that it may become smaller than the cross-sectional area of this.

  In the circuit board 21 configured as described above, a predetermined wiring pattern including the cutoff wiring 30 and both connection wirings 40 and 50 is formed as follows. FIG. 5 is an explanatory diagram for explaining the cutoff wiring 30 and the connection wirings 40 and 50 at the time of molding. 6A is a cross-sectional view taken along the line 6A-6A in FIG. 5, and FIG. 6B is a cross-sectional view taken along the line 6B-6B in FIG.

  First, an etching resist is formed on the surface of the substrate provided with a conductor layer such as a copper foil for constituting the cutoff wiring 30 and the both connection wirings 40 and 50. Next, the etching resist formed in a region different from the wiring pattern is removed by exposure and development processing. And the etching which removes the conductor layer in which the etching resist is not advanced advances by immersing the board | substrate with which the etching resist was formed in the non-etching surface in an etching liquid in this way.

  Around the conductor layer for constituting the cutoff wiring 30 and both connection wirings 40 and 50, the etching solution flows as exemplified by arrows L1 and L2 in FIGS. Is etched. After this etching, by removing the etching resist (indicated by reference numeral 29 in FIG. 6), a predetermined wiring pattern including the blocking wiring 30 and the both connection wirings 40 and 50 is formed on the substrate surface.

  At this time, the side edges 41 and 42 on both sides of the one side connection wiring 40 and the side edges 51 and 52 on both sides of the other side connection wiring 50 are formed so as to be smoothly continuous with the side edges 31 and 32 on both sides of the cutoff wiring 30. Is done. For this reason, in the connection part C1 of the side edge 31 of the interruption | blocking wiring 30 and the side edge 41 of the one side connection wiring 40, and the connection part C2 of the side edge 32 of the interruption | blocking wiring 30 and the side edge 42 of the one side connection wiring 40 The etching solution can easily flow uniformly. Further, at the connection part C3 between the side edge 31 of the cutoff wiring 30 and the side edge 51 of the other side connection wiring 50, and at the connection part C4 between the side edge 32 of the cutoff wiring 30 and the side edge 52 of the other side connection wiring 50, The etching solution can easily flow uniformly. Thereby, the retention of the etchant at the connection parts C1 to C4 is suppressed, and the variation in the wiring width of the blocking wiring 30 at the connection parts C1 to C4 is suppressed.

  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. Thereby, the other electronic components 22 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 overcurrent to the blowout of the interruption wiring 30 is about several mS (milliseconds), and the fusing 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.

  Note that the heat generated in the interruption wiring 30 due to the overcurrent is transferred to the power supply wiring 23 through the one-side connection wiring 40. When the cut-off wiring 30 having a narrow wiring width and the power supply wiring 23 having a wide wiring are directly connected, heat from the cut-off wiring 30 is easily transmitted to the power supply wiring 23, and the temperature of the cut-off wiring 30 is lowered and the temperature is reduced. The decline will vary. Further, not only the same problem occurs with the land 26, but also the heat concentrates in the vicinity of the connection portion with the interruption wiring 30 in the land 26, and the interruption wiring 30 of the solder 25 applied to the land 26 by this heat. When a nearby portion melts, the molten conductor may scatter around.

  In the present embodiment, the heat of the interruption wiring 30 is transmitted through the one-side connection wiring 40 formed so that the cross-sectional area at the connection portion with the interruption wiring 30 is smaller than the cross-sectional area at the connection portion with the power supply wiring 23. Then, heat is transferred to the power supply wiring 23. Further, the heat of the interruption wiring 30 is transferred to the land 26 via the other-side connection wiring 50 formed so that the cross-sectional area at the connection portion with the interruption wiring 30 is smaller than the cross-sectional area at the connection portion with the land 26. Heat is transferred. For this reason, heat is held in the one-side connection wiring 40 and the other-side connection wiring 50, and diffusion of heat to the power supply wiring 23 and the land 26 is suppressed. Thereby, since the dispersion | variation in the heat | fever of the interruption | blocking wiring 30 is suppressed, even if it is the above-mentioned fusing in a short time, the dispersion | variation in the time to fusing will be suppressed. Moreover, since the one side connection wiring 40 and the other side connection wiring 50 have a larger conductor volume than the cutoff wiring 30, heat from the cutoff wiring 30 can be suitably stored.

  As described above, in the traction control device 20 according to this embodiment, the cutoff wiring 30 is connected to the power supply wiring 23 and the land 26 via the one side connection wiring 40 and the other side connection wiring 50. The one-side connection wiring 40 is formed such that the side edges 41 and 42 on both sides are smoothly continuous with the side edges 31 and 32 on both sides of the cutoff wiring 30 and expands in an arc shape toward the power supply wiring 23. . Further, the other side connection wiring 50 is formed such that the side edges 51 and 52 on both sides are smoothly continuous with the side edges 31 and 32 on both sides of the cutoff wiring 30 and spread in an arc shape toward the land 26. Yes.

  As described above, since the side edges of the cutoff wiring 30 and the both connection wirings 40, 50 are gently continuous, when the wirings 30, 40, 50 are formed using an etching solution, the side edges of the cutoff wiring 30 are used. The etching solution can easily flow uniformly at the connection portions C1 to C4 between the side edges 41, 42, 51, and 52 of the connection wires 31 and 32 and the connection wirings 40 and 50. As a result, the retention of the etching solution at the connection portions C1 to C4 is suppressed and the variation in the wiring width of the cutoff wiring 30 is suppressed, so that it is possible to suppress the deterioration of the cutoff performance due to the cutoff wiring 30 provided on the substrate surface. it can.

  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 other electronic control devices 20 are connected to each other. A common fuse 14 a for overcurrent protection of the control device 12 is provided on the power supply path from the battery 13. As a result, even if the traction control device 20 provided with the cutoff wiring 30 is short-circuited or the like, the cutoff wiring 30 can be melted to eliminate the influence on the power supply to the other electronic control devices 12. it can.

FIG. 7 is an explanatory diagram illustrating a main part of the traction control device 20 according to the first modification of the first embodiment. FIG. 8 is an explanatory diagram illustrating a main part of the traction control device 20 according to the second modification of the first embodiment.
As shown in FIG. 7, instead of the one-side connection wiring 40 and the other-side connection wiring 50, the one-side connection wiring 40a and the other-side connection wiring 50a may be employed as a first modification of the first embodiment. .

  Specifically, the one side connection wiring 40 a is such that the side edges 41 and 42 on both sides are smoothly continuous with the side edges 31 and 32 on both sides of the cutoff wiring 30 and expands in a tapered shape toward the power supply wiring 23. Is formed. Further, the other-side connection wiring 50 a is formed so that the side edges 51 and 52 on both sides are continuously continuous with the side edges 31 and 32 on both sides of the cutoff wiring 30 and expands in a tapered shape toward the land 26. Yes.

  Even if it does in this way, it becomes easy to flow an etching solution more uniformly in connection part C1-C4 of the side edges 31 and 32 of the interruption | blocking wiring 30, and the side edges 41, 42, 51, and 52 of both connection wiring 40a, 50a, The retention of the etching solution at the connection sites C1 to C4 can be suitably suppressed.

  Further, as shown in FIG. 8, as a second modification of the first embodiment, instead of the one side connection wiring 40 and the other side connection wiring 50, the one side connection wiring 40b and the other side connection wiring 50b are adopted. Also good. Specifically, one side connection line 40 b of one side edge 41, 42 of both sides is gently continuous with the side edge 31 of the cut-off line 30 and gradually spreads toward the power supply line 23. The other side edge 42 is formed linearly together with the side edge 32 of the blocking wiring 30. The other-side connection wiring 50 b is formed so that one of the side edges 51, 52 on both sides is continuously continuous with the side edge 31 of the cutoff wiring 30 and gradually spreads toward the land 26. The other side edge 52 is formed linearly together with the side edge 32 of the blocking wiring 30.

  Accordingly, the etchant can easily flow smoothly at the other side edges 42 and 52, so that the etchant can be reliably prevented from staying, and the one side edges 41 and 51 can be gently formed as the side edges 31 of the cutoff wiring 30. Therefore, the retention of the etching solution at the connection sites C1 to C4 can be suitably suppressed.

[Second Embodiment]
Next, a traction control device according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 9 is an explanatory diagram showing a main part of the traction control device 20a according to the second embodiment. FIG. 10 is a cross-sectional view taken along the line AA in FIG.

  In the second embodiment, in the traction control device 20a, instead of the one-side connection wiring 40 and the other-side connection wiring 50, the one-side connection wiring 40c and the other-side connection wiring 50c are adopted, and a pair of plate-like wirings are newly added. The point which employ | adopts 60 and 70 mainly differs from the said 1st Embodiment. For this reason, substantially the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 9, the one-side connection wiring 40 c is configured such that the cross-sectional area at the connection site with the cutoff wiring 30 is smaller than the cross-sectional area at the connection site with the power supply wiring 23. The other-side connection wiring 50 c is configured such that the cross-sectional area at the connection site with the cutoff wiring 30 is smaller than the cross-sectional area at the connection site with the land 26.

  In addition, a pair of plate-like wirings 60 and 70 are provided in the vicinity of the cutoff wiring 30 so as to face each other via the cutoff wiring 30. Both plate-like wirings 60 and 70 are made of the same conductive material as copper and the like, and are formed as plate-like wirings without being connected to other wirings.

  The pair of plate-like wirings 60 and 70 includes a distance X1 between the side edge 61 on the side of the cutoff wiring in one plate-like wiring 60 and the side edge 31 of the cutoff wiring 30 facing the side edge 61, and the other plate-like wiring. The distance X2 between the side edge 71 of the wiring 70 on the side of the interruption wiring and the side edge 32 of the interruption wiring 30 facing the side edge 71 is arranged to be substantially equal along the interruption wiring 30.

  In the interruption wiring 30 configured as described above, when immersed in an etching solution, as in the first embodiment, the etching solution is on the side of the interruption wiring 30 as illustrated by arrows L1 and L2 in FIG. It flows between the edge 31 and the side edge 61 of one plate-like wiring 60 and between the side edge 32 of the blocking wiring 30 and the side edge 71 of the other plate-like wiring 70. At this time, since the pair of plate-like wirings 60 and 70 are arranged so that the distance X1 and the distance X2 are substantially equal to each other, the etching solution between the side edges 31 and 61 and between the side edges 32 and 71 is reduced. The flow rate is almost equal.

  As a result, the difference in the amount of etchant flowing through the side edges 31 and 32 on both sides of the cut-off wiring 30 is reduced, and variations in etching progress at the side edges 31 and 32 are suppressed. Thereby, since the dispersion | variation in the wiring width of the interruption | blocking wiring 30 is suppressed, the fall of the interruption | blocking performance by the interruption | blocking wiring 30 provided in a board | substrate surface can be suppressed.

  Note that the pair of plate-like wirings 60 and 70 is not limited to be arranged such that the distance X1 and the distance X2 are substantially equal, but may be arranged so that the difference between the distance X1 and the distance X2 is small. . In addition, the pair of plate-like wirings 60 and 70 is not limited to being formed as a plate-like wiring from a conductive material, but is formed as a non-removed region composed of a member that is not removed during etching using an etchant. Also good.

FIG. 11 is an explanatory diagram showing a main part of a traction control device 20a according to a first modification of the second embodiment. FIG. 12 is an explanatory diagram showing a main part of a traction control device 20a according to a second modification of the second embodiment.
As shown in FIG. 11, as a first modification of the second embodiment, at least one of the pair of plate-like wirings 60 and 70 may be a part of another wiring pattern provided on the circuit board 21. .

  Specifically, instead of the other plate-like wiring 70 described above, a wiring pattern 70 a is formed in the vicinity of the side edge 32 of the blocking wiring 30, and this wiring pattern 70 a is connected to another electronic component 22. Has been. One plate-like wiring 60 is cut off at a distance X1 between the side edge 61 and the side edge 31 of the cutoff wiring 30 to a distance X2 between the side edge 71 of the wiring pattern 70a and the side edge 32 of the cutoff wiring 30. They are arranged along the wiring 30 so as to be substantially equal.

  Even in this case, the difference in the amount of etching solution flowing through the side edges 31 and 32 on both sides of the cut-off wiring 30 is reduced, and variation in etching progress on the side edges 31 and 32 can be suppressed. In particular, as compared with the case where both the plate-like wirings 60 and 70 are arranged close to the cutoff wiring 30, it is not necessary to separately provide the other plate-like wiring 70. The size of the device including the circuit board 21 can be reduced.

  As shown in FIG. 12, as a second modification of the second embodiment, the corner portions 62 and 72 at the side edges 61 and 71 of the two plate-like wirings 60 and 70 may be rounded. As a result, the etching liquid easily flows between the side edges 31 and 32 of the cutoff wiring 30 and the side edges 61 and 71 of both plate-like wirings 60 and 70, and etching at the side edges 31 and 32 on both sides of the cutoff wiring 30 is performed. The variation in the progress of the wiring is further suppressed, and the variation in the wiring width of the cutoff wiring 30 can be reliably suppressed.

[Third Embodiment]
Next, a traction control device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 13 is an explanatory diagram showing a main part of the traction control device 20b according to the third embodiment.

  In the third embodiment, in the traction control device 20b, the pair of plate-like wirings 60 and 70 described in the second embodiment is newly adopted with respect to the configuration of the first embodiment. Different from the first embodiment. For this reason, substantially the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 13, the cut-off wiring 30 is electrically connected to the power supply wiring 23 at one end via the one-side connection wiring 40 described above, and the other-side connection wiring 50 described above is connected to the other end. Via the land 26. A pair of plate-like wirings 60, 70 are provided in the vicinity of the interruption wiring 30 so as to face each other via the interruption wiring 30. The pair of plate-like wirings 60, 70 are connected to the side edges 31, The distance X <b> 1 between 61 and the distance X <b> 2 between the side edges 32 and 71 are arranged to be substantially equal along the cutoff wiring 30.

  As described above, since the side edges of the cutoff wiring 30 and the both connection wirings 40, 50 are gently continuous, when the wirings 30, 40, 50 are formed using an etching solution, the side edges of the cutoff wiring 30 are used. The etching solution can easily flow uniformly at the connection portions C1 to C4 between the side edges 41, 42, 51, and 52 of the connection wires 31 and 32 and the connection wirings 40 and 50. Thereby, the retention of the etching liquid in the connection parts C1 to C4 is suppressed, and the variation in the wiring width of the blocking wiring 30 can be suppressed. In addition, the pair of plate-like wirings 60 and 70 reduces the difference in the amount of etchant flowing through the side edges 31 and 32 on both sides of the cutoff wiring 30 and suppresses variations in etching progress on the side edges 31 and 32. can do.

  As a result, not only the connection portions C1 to C4 between the side edges 31, 32 of the cutoff wiring 30 and the side edges 41, 42, 51, 52 of the both connection wirings 40, 50, but also the side edges 31, 32 on both sides of the cutoff wiring 30. However, since variations related to etching are suppressed and variations in the wiring width of the blocking wiring 30 are suppressed, it is possible to reliably suppress a decrease in blocking performance due to the blocking wiring 30 provided on the substrate surface.

[Fourth Embodiment]
Next, an electronic control unit according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 14 is an explanatory diagram illustrating a main part of the electronic control device 110 according to the fourth embodiment.
In the electronic control device 110 according to the fourth 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. 14, the power supply wiring 23 that supplies power from the battery 13 via the connector 121 is electrically connected to the circuit blocks 130, 140, and 150 via the branch wirings 131, 141, and 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, the function of only the circuit block 130 having the blown cut-off wiring 30 can be stopped, and the functions of the other circuit blocks 140 and 150 can be continued. 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. Even if an overcurrent occurs due to a short circuit failure or the like in the circuit blocks 140 and 150 where the interruption wiring 30 is not provided, the interruption wiring 122 is melted by the overcurrent flowing through the power supply wiring 23, and the circuit blocks 130 and 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 said each embodiment and its modification, You may actualize as follows.
(1) The one-side connection wirings 40, 40a, 40b formed as described above are electrically connected to the common wiring shared by each electronic component 22 that is the target of overcurrent protection, instead of the power supply wiring 23. It may be connected.

(2) The other side connection wirings 50, 50a, 50b formed as described above are not limited to being electrically connected to the land 26. For example, the other side connection wirings 50, 50a, 50b are not limited to electronic components such as inner layer side wiring that is not exposed to the surface layer. You may electrically connect to the component mounting wiring for mounting.

(3) The interruption wiring 30 and the connection wirings 40 and 50 described above are provided for each substrate for overcurrent protection of the plurality of electronic control devices 12 such as the body ECU and navigation device including the engine ECU, brake ECU, and steering ECU described above. It may be adopted.

(4) The cut-off wiring 30 and the pair of plate-like wirings 60 and 70 described above are used for overcurrent protection of a plurality of electronic control devices 12 such as the engine ECU, brake ECU, steering ECU, body ECU, and navigation device. You may employ | adopt for every board | substrate.

(5) A part or all of the interruption wiring 30 may be formed of a material having a lower thermal conductivity than the power supply wiring 23 and the land 26, such as aluminum. As a result, the heat generated in the interruption wiring 30 due to the overcurrent is less likely to be transmitted to the power supply wiring 23 and the land 26, so that variations in temperature rise in the interruption wiring 30 are suppressed, and the interruption performance due to the interruption wiring 30 is reliably reduced. Can be suppressed.

DESCRIPTION OF SYMBOLS 10 ... Automobile 11 ... Vehicle control system 12 ... Electronic control device 13 ... Battery 14a, 14b ... Fuse 20, 20a, 20b ... Traction control device (electronic control device)
21 ... Circuit board 22 ... Electronic component 23 ... Power supply wiring (object to be connected)
24, 24d ... Ceramic capacitor 26 ... Land (target for connection)
30 ... Cut-off wiring 31, 32 ... Side edge 40, 40a ... One side connection wiring 50, 50a ... Other side connection wiring 60, 70 ... Plate-like wiring (non-removal region)
61, 71 ... side edges

Claims (1)

A cut-off wiring that cuts off a connection with a connection target when fusing in response to heat generation due to overcurrent is a method for manufacturing a wiring board that is connected to the connection target via a connection wiring and formed on the substrate,
A first step of preparing a substrate provided with a conductor layer for constituting the blocking wiring and the connection wiring;
A second step of forming an etching resist on the conductor layer;
Of the etching resist, the etching resist formed in a region different from the wiring pattern including the blocking wiring and the connection wiring is removed, and a side edge of the etching resist on the conductor layer corresponding to the connection wiring is A third step of leaving the etching resist so as to gradually spread toward a side of the connection target and continuously with a side edge of the etching resist on the conductor layer corresponding to the blocking wiring;
A fourth step of immersing the substrate in an etching solution for removing the conductor layer on which the etching resist is not formed;
A fifth step of removing the etching resist from the substrate after the immersion;
A method for manufacturing a wiring board, comprising:

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