JP2000171326A - Water wetting sensor and electronic control circuit board with water wetting sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a water wetting sensor moutableing on a printed wiring board loaded on a vehicle and ensure the detection of a water wetting in an electronic control circuit. SOLUTION: This water wetting sensor comprises a pair of detection parts 19a, 20a arranged opposite to each other with a prescribed space on an insulating substrate 30, a detecting circuit element loaded on the insulating substrate 30 to output a detection signal of a prescribed level when water is present between the detection parts 19a, 20a to carry a leak current, and terminals 34, 35, 36, 37 mounted on the insulating substrate 30, electrically conducted to the detection parts 19a, 20a and the detecting circuit element 21a and connected to the wiring conductor of an electronic control circuit board. The detecting circuit element 21a is provided with an amplifier circuit for amplifying the leak current carried between the detection parts 19a, 20a and an output circuit for outputting the detection signal of a prescribed level by the amplification of the leak current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water wetting sensor for detecting water wetting due to submersion of an electronic control circuit mounted on a vehicle such as an automobile, and an electronic control circuit board provided with the water wetting sensor. .

[0002]

2. Description of the Related Art In recent years, computerization of vehicles such as automobiles has progressed.
Generally, a control unit provided with an electronic control circuit is mounted. In such a control unit, for example, when the control circuit gets wet with water due to flooding of the vehicle or the like, the circuit may malfunction. For this reason, in the conventional control unit, the printed circuit board that constitutes the electronic control circuit is housed in a dedicated box, and a waterproof structure is provided to prevent water from entering, so that the control circuit is protected from water intrusion. ing.

[0003]

However, when a waterproof structure as described above is provided, a waterproof packing and a molding resin are required, and the assembling work of the control unit becomes complicated. However, the structure is extremely complicated, and the cost cannot be avoided. Therefore,
Instead of adopting such a heavy equipment waterproof structure, a water wetting sensor that detects the water wetting of the electronic control circuit due to submersion of the vehicle etc. is mounted on a printed wiring board that constitutes the electronic control circuit, and the electronic control circuit It is conceivable to prevent a malfunction on the basis of a detection signal from a water-wetting sensor when the camera is wet.

In this case, it is conceivable to divert a raindrop sensor conventionally used for detecting raindrops as a water wetness sensor. However, since this raindrop sensor is generally configured to be suitable for detecting raindrops at a location distant from the electronic control circuit, it is mounted on a printed circuit board to detect water wetting of the electronic control circuit itself. There are difficulties in using it. That is, since the raindrop sensor requires a large detection electrode having a comb shape or the like as a detection unit for detecting the raindrop, the size of the sensor itself increases, and it is difficult to mount the raindrop sensor on a printed wiring board. In addition, a dedicated detection circuit is required to perform stable detection regardless of fluctuations in the detection current flowing between the detection electrodes, but the electronic components that make up this detection circuit are separated from the water wetness sensor by a printed circuit board. There is a problem in that when it is mounted on top, the required space further increases, and it takes time and effort to mount.

The present invention has been made in view of such circumstances, and can be easily mounted on a printed wiring board constituting an electronic control circuit, and can surely detect the wetness of the electronic control circuit. It is an object of the present invention to provide a water wetting sensor that can be used and an electronic control circuit board including the water wetting sensor.

[0006]

According to one aspect of the present invention, there is provided a water wetness sensor mounted on an electronic control circuit board mounted on a vehicle and detecting water wetness of the electronic control circuit. A pair of detectors made of a conductive material opposed to each other at a predetermined interval, and a detection circuit for outputting a detection signal of a predetermined level when water is interposed between the detectors and a leak current flows. And a terminal electrically connected to the detection section and the detection circuit and connected to a wiring conductor of the electronic control circuit board is held by a base member.

[0007] According to this configuration, the water wetting sensor is as simple as incorporating a pair of detecting portions, a detecting circuit, and a terminal in the base member. Therefore, the terminal is provided on the printed wiring board constituting the electronic control circuit. Therefore, the electronic control circuit can be easily mounted, and the wetness of the electronic control circuit can be reliably detected. That is, when the electronic control circuit becomes wet due to submersion or the like, water is interposed between the detection units of the water wetting sensor, and a leak current flows between the detection units. However, the value of the leak current fluctuates. Also, since the detection circuit always outputs a detection signal of a predetermined level, the electronic control circuit can surely detect the water wet state and perform an appropriate operation.

According to a second aspect of the present invention, in the first aspect, the detecting circuit amplifies a leak current flowing between the detecting sections, and the amplifying circuit amplifies the leak current. And an output circuit for outputting a detection signal of a predetermined level.

According to this configuration, when the electronic control circuit becomes wet due to water submersion or the like, the leak current flowing between the detection units is amplified by the amplifier circuit, and the output circuit is driven by the amplified leak current to drive the output circuit to a predetermined level. As a result of the output of the level detection signal, the wet condition is reliably detected, and the electronic control circuit can perform an appropriate operation.

According to a third aspect of the present invention, in accordance with the second aspect, the detection circuit continues the detection signal of a predetermined level even when the leakage current flowing between the detection units decreases or disappears. And a latch circuit for outputting the data.

According to this configuration, once a leak current flows between the detection units, a detection signal of a predetermined level is continuously output due to the presence of the latch circuit even if the leak current subsequently decreases or disappears. For this reason, even if the leak current decreases or disappears to such an extent that it cannot be recognized as wet, despite the fact that the detecting unit is gradually oxidized, the wet state is continuously detected. The control circuit can perform an appropriate operation.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the base member is formed of an insulating substrate, and the detecting section is disposed on the insulating substrate. The terminal is constituted by a metal member, the electronic component constituting the detection circuit is mounted on the insulating substrate, and the electronic component is connected to the detection unit and the terminal. It is characterized by having a circuit configuration.

According to this configuration, the water wetting sensor is mounted on the printed wiring board that forms the electronic control circuit, and the detection unit formed of a film conductor and the detection circuit are connected via the terminal formed of a metal member attached to the insulating substrate. Connected to the electronic control circuit. In addition, the film conductor here is a conductor formed by applying a conductive paste to an insulating substrate by pattern printing or the like and then performing a baking process, a conductor made of a copper foil or the like formed by applying photoengraving technology, A conductor or the like formed by evaporating a metal material.

According to a fifth aspect of the present invention, in accordance with the fourth aspect, the insulating substrate is covered with an insulating material in a state where the pair of detecting portions are exposed to the outside. I have.

According to this structure, the mechanical strength of the insulating substrate is enhanced, and the handling performance is improved. Even when the insulating substrate is mounted on a printed wiring board by an automatic mounting machine, there is almost no possibility of breakage. Further, even if stress occurs in the insulating substrate, the insulating substrate is less likely to be damaged, and the detection circuit is also protected from external pressure and the like, so that the reliability is improved.

According to a sixth aspect of the present invention, in the device according to any one of the first to third aspects, the detecting portion and the terminal are provided in the base member with at least one end exposed to the outside. The detection circuit is formed of a metal plate provided, and the detection circuit is provided in the base member.

According to this configuration, the detection section and the terminal are held by the base member to be stiff, and the detection circuit is disposed in the base member, so that the handling performance is improved.
Further, since the structure is simplified and the size is reduced, it is more suitable for mounting on a printed wiring board.

According to a seventh aspect of the present invention, in the sixth aspect, the base member is formed of an insulating member formed by molding, and the detecting portion and the terminal are provided outside the metal plate. The detection circuit is formed by an exposed end, and the detection circuit has a circuit configuration in which electronic components constituting the detection circuit are mounted on the metal plate, and the electronic component is connected to the detection unit and the terminal. It is characterized by.

According to this configuration, the water wetting sensor is mounted on the printed wiring board that forms the electronic control circuit, and the detection unit including the end of the metal plate exposed to the outside of the insulating member and the electronic component are mounted on the metal plate. Is connected to the electronic control circuit via a terminal consisting of an end of a metal plate exposed to the outside of the insulating member.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, a hollow portion is formed between the pair of detecting portions.

According to this configuration, for example, even if the surrounding environment of the printed wiring board becomes humid, it is possible to prevent a short circuit between the detection units of the water wetting sensor due to dew condensation. For this reason, the water wetting sensor is prevented from recognizing even a very small amount of water droplets as being wet, and it is possible to more reliably detect a water-wetted state due to submersion or the like.

As described above, the water wetting sensor according to the present invention has a simple and compact structure, so that it can be configured to be easily mounted on a printed wiring board like other electronic components. For example, the invention according to claim 9 is characterized in that, in any one of claims 1 to 8, the terminal has a surface mounting shape and is attached to a facing edge of the base member. I have.

According to this configuration, the water wetting sensor is surface-mounted on the printed wiring board constituting the electronic control circuit by the terminal having the surface mounting shape. That is, the water wetting sensor is connected to the printed circuit board with its terminals in contact with the wiring conductor formed on the surface of the printed circuit board, and attached to the printed circuit board.

The invention according to claim 10 is the first invention.
The terminal according to any one of the first to eighth aspects, wherein the terminal has a lead wire shape and is attached to a facing edge of the base member so as to extend in opposite directions.

According to this configuration, the water wetting sensor is mounted on the printed wiring board constituting the electronic control circuit by the terminal having a lead wire shape. That is, the terminal is inserted into the mounting hole of the printed wiring board, is connected to the wiring conductor, and is attached to the printed wiring board in such a state that the base member is substantially horizontal to the printed wiring board surface. Can be

The invention according to claim 11 is the first invention.
The terminal according to any one of the first to eighth aspects, wherein the terminal has a lead wire shape and is attached to an edge of the base member so as to extend in the same direction.

According to this configuration, the water wetting sensor is mounted on the printed wiring board constituting the electronic control circuit by the terminal having a lead wire shape. That is, the water wetting sensor is in a state where its terminals are inserted into the mounting holes of the printed wiring board constituting the electronic control circuit and connected to the wiring conductor, and the base member is substantially perpendicular to the printed wiring board surface. Is attached to the printed circuit board.

According to a twelfth aspect of the present invention, there is provided an electronic control circuit board mounted on a vehicle, wherein various electronic components constituting a control circuit on a wiring board and the electronic control circuit board according to any one of the first to eleventh aspects. It is characterized in that a circuit is configured by mounting a water wetness sensor.

According to this configuration, in the water wetting sensor mounted on the printed wiring board, the detection unit and the detection circuit are connected to the electronic control circuit via the terminals. For this reason, when the electronic control circuit becomes wet due to submersion of the vehicle or the like, water is interposed between the detection units and a leak current flows between the detection units. As a result of the circuit always outputting a detection signal of a predetermined level, the electronic control circuit can surely detect the water wet state and perform an appropriate operation.

[0030]

FIG. 1 is a diagram showing an example of an electronic control circuit to which a water wetness sensor according to an embodiment of the present invention is applied. The electronic control circuit 10 is employed in a power window mechanism of an automobile, and when the electronic control circuit 10 itself becomes wet due to submersion of a vehicle or the like, a window that has been opened due to a malfunction of the electronic control circuit 10 can be used without permission. It does not close.

That is, the electronic control circuit 10 comprises a first output amplifier 11 constituted by an OR circuit, first switch means 12 connected to one input terminal of the first output amplifier 11, A second switch means 14 is connected to the other input terminal of the amplifier 11 via a control unit (electronic control circuit board) 13. The first switch means 12 is configured to output an ON signal only while the switch operation by the occupant is continued, and the second switch means 14 is operated by an output preamplifier 17 described later. Once the occupant performs the ON operation, the ON signal is continuously output unless the occupant performs the OFF operation. These first and second
Each of the switch means 12 and 14 is provided with a waterproof structure or the like so that it does not malfunction even when it is wet.

The control unit 13 controls the printed circuit board 1
5, an output preamplifier 17 connected to one input terminal of the second output amplifier 16, and a second output amplifier 16
And a water wetting sensor 18 connected to the other input terminal. The output preamplifier 17 is configured to output an ON signal continuously by temporarily operating the second switch means 14 as described above. In addition, the water wetting sensor 18 detects a pair of detecting portions 19 and 20 for detecting wetting and a leak current flowing when water is interposed between the pair of detecting portions 19 and 20, and
A detection circuit 21 for outputting a detection signal of a preset predetermined level even when the value of the leakage current fluctuates and becomes unstable, and is connected to a battery 23 via a voltage dividing resistor 22. ing.

In this embodiment, the detection circuit 21 is provided as shown in FIG.
As shown in (a), a pnp-type first transistor TR that amplifies a leak current flowing between the detection units 19 and 20
_1, is configured to include a second transistor TR ₂ of the npn type which outputs a given level of detection signal which is set in advance by the leakage current is amplified by the first transistor TR _1. The collector of the second transistor TR ₂ is,
The second output amplifier 16 is connected to the other input terminal in a state where a voltage for outputting a detection signal of a predetermined level is applied via an adjustment resistor. The detection circuit 21 configured as described above, as shown in the block diagram in FIG. 2 (b), an amplifier circuit 211 configured to include a first transistor TR _1, is configured to include a second transistor TR ₂ Output circuit 212. In addition,
In the present embodiment, the first output amplifier 11 is disposed outside the printed wiring board 15 so that a malfunction does not occur even if the first output amplifier 11 becomes wet due to a waterproof structure. It is also possible to mount it on the wiring board 15.

In this configuration, when the electronic control circuit 10 is not wet, the first switch 12
When either one of the second switch means 14 is operated, the drive motor 24 for opening and closing the power window is driven by the control signal output from the output terminal of the first output amplifier 11, and the open window is closed. Will be done. That is, when the electronic control circuit 10 is not in the wet state, the detection unit 19 of the water wet sensor 18
Since a high resistance is maintained between the transistors 20, the first and second transistors TR ₁ and TR ₂ are both in a non-conductive state, so that a high signal is input to the other input terminal of the second output amplifier 16. When the second switch means 14 is operated so that a high signal is also input to one input terminal of the second output amplifier 16, the drive motor 24 is driven and the open window is closed. become.

On the other hand, when the electronic control circuit 10 becomes wet due to the submersion of the vehicle or the like, a leak current flows between the detectors 19 and 20, and the resistance between the detectors 19 and 20 becomes a low resistance state. As a result of the two transistors TR ₁ and TR ₂ both conducting, a low signal is input to the other input terminal of the second output amplifier 16. Therefore, even if the second switch means 14 is operated to input a high signal to one input terminal of the second output amplifier 16, the drive motor 24 is not driven, and the open window is opened. Will not be closed. Therefore, the power window can be closed only by operating the first switch means 12, so that the inconvenience of closing the power window against the occupant's will is avoided.

As described above, the provision of the detection circuit 21 in the water wetness sensor 18 may cause an unstable state in which the leakage current flowing between the detection units 19 and 20 fluctuates and decreases. Also the leakage current is the first transistor TR
Is amplified by _1, since this by amplified current second transistor TR ₂ is to be driven, the detection signal of a predetermined level at all times is preset from the second transistor TR ₂ collector output, submerged, etc. Can reliably detect a water-wetting state, thereby providing excellent reliability.

Further, as the detecting circuit 21, as shown in FIG. 3 (a), the output signal from the transistor TR ₂ latches, after latching the output signal from the transistor TR ₂ is extinguished Also has a configuration in which a latch circuit element FF including a flip-flop or the like that continuously outputs a low signal is provided at the other input terminal of the second output amplifier 16.
It is possible to more reliably detect a water wet state due to submergence or the like.

[0038] That is, the detection unit 19 and 20, for example, when a copper foil is configured, as shown in FIG. 4 (a), the initial predetermined time became wet state (t ₀ ~t ₁₎ in Leaks a leak current (sensing current) exceeding a current value Ia necessary to determine that the water is wet, but after a predetermined time has elapsed, copper ions are eluted from the detection units 19 and 20 or the detection units 19 and 20 The leak current is reduced in spite of being in a water-wet state due to generation of gas due to electrolysis and oxidation of the surfaces of the detection units 19 and 20 in the water 20, resulting in a water-wet state. There is a case where the current value Ia required to determine that the current value is lower than the current value Ia. In such a case, the detection circuit 21 shown in FIG. 2, this means that the leakage current becomes below the current value Ia is the transistor TR ₂ high signal in the non-conductive state which is not driven is output, the electronic control circuit 10 Erroneous operation may cause the opened window to close without permission.

[0039] In contrast, by providing the latch circuit element FF, the second transistor low signal from the TR ₂ and the leakage current of a predetermined value flows between detection portions 19 and 20 is output the low signal is latched Therefore, as shown in FIG. 4B, even if the leakage current between the detection units 19 and 20 decreases or disappears after a predetermined period of time, the latch circuit element FF
Therefore, the low signal is continuously output, and the malfunction of the electronic control circuit 10 due to water wetting can be reliably prevented. Incidentally, the detection circuit 21 having a latch circuit element FF, as shown in the block diagram in FIG. 3 (b), an amplifier circuit 213 configured to include a first transistor TR _1, the second transistor TR ₂ and the latch A latch circuit 214 including the circuit element FF and an output circuit 215 including the latch circuit element FF are provided.

FIG. 5 is a diagram showing the configuration of the first embodiment of the water wetness sensor 18 suitable for mounting on the printed wiring board 15 constituting the electronic control circuit 10. As shown in FIG. The water wetting sensor 18a shown in FIG. 5 has a circuit configuration as shown in FIG. 2, and is provided at a predetermined interval on a rectangular insulating substrate 30 made of an alumina substrate, a synthetic resin substrate, or the like as a base member. A pair of detecting portions (lands) 19a and 20 for detecting water wetting made of a conductive material formed to face each other.
a, an integrated detection circuit element 21a mounted on the insulating substrate 30 and constituting the detection circuit 21; and a detection unit 20a and the detection element circuit 31 formed on the insulating substrate 30.
And a plurality of connection conductors 33 formed on the insulating substrate 30 and connected to the detection unit 19a and the detection circuit element 21a, respectively, and arranged to extend to edges facing each other. , A plurality of terminals 3 attached to the edge of the insulating substrate 30 and connected to each connection conductor 33.
4, 35, 36, and 37. In addition, between the respective detection units 19a, 20a of the insulating substrate 30, and between the respective detection units 19a,
H-shaped slits 38 penetrating both sides of the insulating substrate 30 are formed on both left and right sides of the insulating substrate 20a.

The detectors 19a and 20a and the connection conductors 32,
Reference numeral 33 denotes, for example, a conductive paste obtained by applying a conductive paste on the insulating substrate 30 by means such as pattern printing and then performing a baking treatment, or a copper foil or the like obtained by using a photoengraving technique or the like. It is formed of a conductor or a conductor obtained by evaporating a metal material. In the present invention,
The conductor obtained by these forming means is called a film conductor. The detection units 19a and 20a are, for example, approximately 1.2 m on one side.
Although they are set to have a square shape of m and are opposed to each other with an interval of, for example, about 1.3 mm, the dimensions can be appropriately increased or decreased according to the application or the like.

The terminals 34 to 37 are formed by bending a metal plate (metal member) made of iron or the like to have a step-like shape including upper flat portions 341 to 371, lower flat portions 342 to 372, and vertical portions 343 to 373. With a surface-mounted shape
The upper flat portions 341 to 371 are connected to the connection conductor 33 by means such as soldering, and the lower flat portions 342 to 372 are brought into contact with the wiring conductor of the printed wiring board 15 and connected by means such as soldering. At this time, a gap of a predetermined size is formed between the insulating substrate 30 and the printed wiring board 15 due to the presence of the vertical portions 343 to 373. Although four terminals 34 to 37 are provided in the present embodiment, the number of terminals may be three, for example, and may be five or more when the detection circuit element 21a has a latch circuit. Although five connection conductors 32 and 33 are provided in the present embodiment, the connection conductors 32 and 33 may be appropriately changed according to the circuit configuration.

The slit 38 has, for example, a facing width of about 0.8.
mm, the electronic control circuit 10 avoids sensing even water droplets due to condensation when placed in a humid surrounding environment, and a water wet state due to submergence actually occurred. It is for sensing only in the case. That is, if the electronic control circuit 10 is placed in a humid environment without the slit 38 being formed, water droplets are interposed between the detection units 19a and 20a due to dew condensation, and the electronic control circuit 10 is submerged by water or the like. There is a risk that the control circuit 10 may be determined to be in a water-wet state. However, if the slit 38 is formed, minute water droplets due to dew condensation are sucked into the slit 38 by surface tension.
The sensing of the water wetting sensor 18a is blocked. Although the slit 38 has an H shape in the present embodiment, the same effect can be obtained by forming an I shape only between the detection portions 19a and 20a.

The water wetting sensor 18a thus configured
Has a simple configuration in which the pair of detection units 19a and 20a, the detection circuit element 21a, and the terminals 34 to 37 are incorporated into the insulating substrate 30. Means can be mounted on the printed wiring board 15 by using an automatic mounting machine having means and the like, and the occupied area on the printed wiring board 15 because the detection units 19a and 20a can be reduced in size and downsized. Can be reduced, and since the detection circuit is provided, the electronic control circuit
Can be reliably detected.

When the water wetting sensor 18a is mounted on the printed wiring board 15, a gap having a predetermined size is formed between the printed circuit board 15 and the printed wiring board 15, as described above. Even when a minute amount of water droplets due to dew condensation adheres, the suction effect by the surface tension in the slit 38 can be made to function more reliably. Further, if a gap is formed on the printed wiring board 15, another electronic component can be mounted or a wiring pattern can be formed in that portion, and the mounting density and wiring of the component on the printed wiring board 15 can be improved. It is possible to increase the density.

The water wetting sensor 18a is connected to the insulating substrate 3
0, a pair of detecting portions 19a and 20a, and a detecting circuit element 21
a, and a simple configuration incorporating the terminals 34 to 37 facilitates assembly and is excellent in mass productivity.

Note that, as shown in FIG.
If the insulating substrate 30 is covered with an insulating material 40 such as a synthetic resin by means of molding or the like in a state where the insulating substrates 9a and 20a are exposed from the window 39, the mechanical strength of the insulating substrate 30 is increased. As a result, the handling performance of the water wetness sensor 18a is improved, and there is almost no possibility of breakage even when mounting on the printed wiring board 15 by an automatic mounting machine. In addition, the insulating substrate 30 is hardly damaged even when stress is generated, and the detection circuit element 21a is also protected from external pressure and the like, so that the reliability of the water wetness sensor 18a is improved. The operation reliability of 10 is also improved. In the water wetting sensor 18a shown in FIG. 6, the dimensions of the terminals 34 to 37 are made larger than those shown in FIG.

The terminals 34 to 37 are formed in a step-like manner so that a gap is formed between the water wetting sensor 18a and the printed wiring board 15, but the terminals 34 to 37 are not necessarily connected to the printed wiring board 15. It is not necessary to configure the shape so that a gap can be formed therebetween. Further, the terminals 34 to 37 may be formed of film conductors using the same forming means as the detection portions 19a and 20a and the connection conductors 32 and 33. The slit 38 does not necessarily need to be formed when there is no possibility that a minute amount of water droplets due to dew condensation is present between the pair of detection units 19a and 20a. Further, the insulating substrate 30 may have a multilayer structure, and the connection conductors 32 and 33 may be embedded in the substrate.

FIG. 7 is a diagram showing the configuration of the second embodiment of the water wetting sensor 18. The water wetting sensor 1 shown in FIG.
8b is a plurality of strip-shaped metal plates 42, 43, 4 made of iron or the like.
4, 45, 46, both ends of the metal plate 42 and the metal plate 4
An insulating member 47 serving as a base member obtained by molding with an insulating material such as a synthetic resin in a state where one end of each of 3, 44, 45, and 46 is exposed, and a detection circuit provided in the insulating member 47. The circuit is composed of an element 21a and a circuit as shown in FIG.

That is, the metal plate 42 is formed by press molding or the like to form an upper flat plate portion 421, a middle flat plate portion 422, and a lower flat plate portion 42.
3, a stepped shape having a vertical portion 424 connecting the upper flat plate portion 421 and the middle flat plate portion 422, and a vertical portion 425 connecting the middle flat plate portion 422 and the lower flat plate portion 423,
The metal plate 43 is formed by pressing the upper plate portion 431, the lower plate portion 432, and the upper plate portion 431 and the lower plate portion 432.
And has a vertical portion 433 that connects them. The upper plate portions 421 and 431 of the metal plates 42 and 43 are opposed to each other in a state where the upper plate portions 421 and 431 are exposed on the surface of the insulating member 47 to form the detecting portions 19b and 20b. The embedded portion in the inside constitutes the connection conductor 48, the vertical portion 433 and the lower plate portion 432 constitute the connection conductor 49, and the middle plate portion 4
The exposed portion from the insulating member 47, the vertical portion 425, and the lower flat plate portion 423 constitute the terminal 50.

The metal plates 44, 45, 46 are formed by press molding or the like to form upper plate portions 441, 451, 461 and lower plate portion 44.
2, 452, 462, and upper flat plate portions 441, 451,
It has a vertical portion 443, 453, 463 connecting the lower plate portion 461 and the lower flat plate portions 442, 452, 462. Then, the upper plate portions 441 and 45
The embedded portions of the insulating members 47 in the insulating members 47 constitute connection conductors 51, 52, and 53, respectively.
Exposed portions 451 and 461 from insulating member 47, vertical portion 4
43, 453, 463 and lower plate portions 442, 452, 4
Reference numeral 62 denotes terminals 54, 55, and 56, respectively. These terminals 50 and 54 and terminals 55 and 56
The insulating members 47 are formed at mutually opposing edges.

The detection circuit element 21a is disposed at an end of the connection conductor 51, and each lead wire is connected to each end of the connection conductors 51, 52, 53. Note that a slit 57 is formed between the detection portions 19b and 20b of the insulating member 47 and penetrates the front and back surfaces of the insulating member 47 as in the first embodiment.

As in the case of the first embodiment, the detectors 19b and 20b are set, for example, in a square shape having a side of about 1.2 mm, and are opposed to each other at an interval of about 1.3 mm, for example. The dimensions can be appropriately changed according to the application and the like. Also, the terminals 50, 54, 55, 56
It has a surface mounting shape, and the lower flat plate portions 423, 442,
452 and 462 are in contact with the wiring conductors of the printed wiring board 15 and connected by means such as soldering. At this time, the presence of the vertical portions 425, 443, 453 and 463 allows the insulating member 47 and the printed wiring board 15 to be connected. A gap of a predetermined size is formed between them. The terminals 50 and 5
In the present embodiment, 4, 55 and 56 are provided with four,
The number may be three, and may be five or more when the detection circuit element 21a has a latch circuit. Also, the number of the connection conductors 48, 49, 51, 53 is appropriately changed according to the circuit configuration.

The water wetting sensor 18b thus configured
Is mounted on the printed wiring board 15 by using an automatic mounting machine equipped with a suction means, a gripping means, etc., similarly to other electronic components having a surface mounting structure because the structure is simplified and compact. And the detection unit 1
9b, 20b, etc. can be made smaller and more compact, so that the occupied area on the printed wiring board 15 can be made smaller. Since the detection circuit is provided, it is ensured that the electronic control circuit 10 is wet by water or the like. Can be detected. The printed wiring board 15
When mounted on the printed wiring board 15, a gap having a predetermined size is formed between the printed circuit board 15 and the pair of detecting portions 19b, 2
Even when a very small amount of water adheres due to condensation during 0b, the suction effect by the surface tension in the slit 57 can be made to function more reliably.

If a gap is formed on the printed wiring board 15, another electronic component can be mounted or a wiring pattern can be formed in that space, and the component can be mounted on the printed wiring board 15. It is possible to increase the density and the wiring density. Further, the detection unit 19b, the connection conductor 48 and the terminal 50, the detection unit 20b and the connection conductor 49,
In addition, since the connection conductors 51 to 53 and the terminals 54 to 56 are integrally formed by the metal plates 42 to 46,
There is no possibility that a connection failure or the like occurs between the members, and the operation reliability is improved. In addition, the water wetting sensor 18b
Metal plates 42 to 46 and molded insulating member 4
7 and the detection circuit element 21a, the assembly is easy, and the mass productivity is excellent.

On the upper flat plate portions 421 and 431 serving as the detection portions 19b and 20b, another metal material capable of enhancing the function of detecting the wet state of the water or a metal material capable of preventing corrosion by contaminants in the air and the like are provided. It is also possible to attach or stick. The terminals 50, 54, 55, and 56 do not necessarily need to be formed in a shape that can form a gap with the printed wiring board 15. Also, terminals 50, 54, 5
Reference numerals 5 and 56 have surface mounting shapes similar to those in the first embodiment, and are connected to the wiring conductors of the printed wiring board 15, but are mounted by being inserted into the mounting holes of the printed wiring board 15. It is also possible to adopt a lead wire shape.

When the terminals 50, 54, 55, and 56 are formed in the form of lead wires, the terminals 50, 54, 55, and 56 may be provided so as to extend in opposite directions from the opposite edges of the insulating member 47. A so-called radial shape may be provided so as to extend from the edge in the same direction.
Further, the connection conductors 48, 51, 52, 53 are connected to the terminals 50,
54, 55, and 56 (in this case, the terminal 50 is directly connected to the detection unit 19b,
The terminals 54, 55, and 56 are directly connected to the detection circuit element 21a. ).

The water wetting sensor 18b shown in FIG.
A pair of detecting portions 19b and 20b are arranged opposite to each other on the insulating member 47, and the pair of detecting portions 19b and 2
Although it is configured such that a slit 57 for dividing the space between 0b is formed, it may be configured such that the pair of detecting portions 19b and 20b are opposed to each other in a hollow state. That is, as shown in FIG. 8, a detection hole (through hole) 5 penetrating through the insulating member 47 on both front and back surfaces and having a width larger than the width of the detection portions 19b and 20b.
8 is formed along the longitudinal direction of the metal plates 48 and 49, and at least a part of the pair of detecting portions 19b and 20b is
8 may be exposed.

In the water wetting sensor 18b shown in FIG. 8 configured as described above, even when the apparatus is placed in a humid environment, it is possible to avoid sensing water droplets due to dew condensation. Only can be reliably detected. In this case, for example, the insulating member 47 can be configured by a case member in which the metal plates 48, 49, 51, 52, and 53 are sandwiched between the upper case and the lower case. In addition, the detection unit 19 in the detection hole 58
The ends of b and 20b may be bent at a right angle, and the bent portions may be opposed to each other. Further, the detecting unit 1
9b and 20b may be arranged to face each other in a hollow state above the insulating substrate 43. In this case, the detection hole 58 is not necessarily required.

FIG. 9 is a diagram showing the configuration of the third embodiment of the water wetting sensor 18. The water wetting sensor 1 shown in FIG.
Reference numeral 8c denotes an insulating substrate 6 having a circuit configuration as shown in FIG.
A pair of detecting portions 19 made of a conductive material and formed at a predetermined distance from each other so as to face each other.
c, 20c, the detection circuit element 21a mounted on the insulating substrate 60, and the detecting unit 20c formed on the insulating substrate 60.
And a connection conductor 61 connecting the detection circuit element 21a and the detection circuit element 21a. The connection conductor 61 is formed on the insulation substrate 60, is connected to the detection unit 19c and the detection circuit element 21a, and is disposed to extend to the opposite edge of the insulation substrate 60. It comprises a plurality of connection conductors 62 and a plurality of terminals 63, 64, 65, 66 attached to the edges of the insulating substrate 60 and connected to the respective connection conductors 62. The insulating substrate 60 is covered with an insulating material 68 such as a synthetic resin by means such as molding in a state where a window 67 is provided to be exposed to the outside. Further, the pair of detecting portions 19 of the insulating substrate 60
H-shaped slits 69 penetrating both the front and back surfaces of the insulating substrate 60 are formed between c and 20c and on both left and right sides of each of the detection units 19c and 20c.

The detectors 19c and 20c and the connection conductors 61,
Reference numeral 62 denotes a film-like conductor formed by the same forming means as that of the first embodiment.
The dimensions of 20c are the same as those of the first embodiment. The terminals 63 to 66 are made of a metal plate (metal member), but are not formed stepwise as in the first embodiment, but are formed by bending the distal end side downward from the opposite edge of the insulating substrate 60. It has a lead wire shape connected to the connection conductor 62 so as to extend in the opposite direction (so-called axial shape), and is inserted into a mounting hole of the printed wiring board 15 and connected to the wiring conductor of the printed wiring board 15. Is done. The number of the terminals 63 to 66 is four in the present embodiment, but may be three, and may be five or more when the detection circuit element 21a has a latch circuit. is there. Also, the number of connection conductors 61 and 62 is appropriately changed according to the circuit configuration.

The projecting portions 70 and 71 are formed along the edge of the insulating material 68 on the bottom surface side (the mounting surface side to the printed wiring board 15) and on the side where the terminals 63 to 66 are mounted. When the water wetting sensor 18 c is mounted on the printed wiring board 15, a gap having a predetermined size is formed between the water wetting sensor 18 c and the printed wiring board 15. Although not shown, the insulating material 6
A similar window portion is formed at a position corresponding to the window portion 67 on the bottom surface side 8 so that the slit 69 is exposed to the outside.

The water wetting sensor 18c thus configured
Has a simple configuration in which the pair of detection units 19c and 20c, the detection circuit element 21a, and the terminals 63 to 66 are incorporated into the insulating substrate 60, and thus, like the other lead-type electronic components, the suction unit and the gripper are used. The terminals 63 to 66 can be inserted into the mounting holes of the printed wiring board 15 and mounted on the printed wiring board 15 by using an automatic mounting machine having means and the like, and the detection units 19c, 20c, etc. The size of the electronic control circuit 10 can be reduced because the size of the electronic control circuit 10 can be reduced because the area occupied on the printed wiring board 15 can be reduced. Will be able to Further, when mounted on the printed wiring board 15, a gap of a predetermined dimension is formed between the printed wiring board 15 and the printed circuit board 15, so that a pair of detecting portions 19c, 20c is formed.
Even in the case where water droplets due to dew condensation adhere during the operation, the suction effect by the surface tension in the slit 69 can be made to function more reliably.

If a gap is formed between the printed wiring board 15 and the water wetting sensor 18c, another electronic component can be mounted on the gap or a wiring pattern can be formed. And the wiring density can be increased. Further, the mechanical strength of the insulating substrate 60 is increased by the presence of the insulating material 68, so that the water wetness sensor 1
The handling performance of the device 8 is improved, and there is almost no possibility of breakage even when the device 8 is mounted on the printed wiring board 15 by an automatic mounting machine. Further, the presence of the insulating material 68 makes it difficult for the insulating substrate 60 to be damaged even when stress is generated, and also protects the detection circuit element 21a from external pressure and the like, thereby improving the reliability of the water wetness sensor 18c. As a result, the operation reliability of the electronic control circuit 10 is also improved.

The water wetting sensor 18c is connected to the insulating substrate 6
0, a pair of detection units 19c and 20c, and a detection circuit element 21
a and a simple configuration incorporating the terminals 63 to 66, the assembly is easy and the mass productivity is excellent.

The protrusions 70 and 7 are provided on the bottom side of the insulating material 68.
Although a gap is formed on the printed wiring board 15 by forming 1, the projections 70 and 71 may be removed so that no gap is formed on the printed wiring board 15. In addition, when there is no possibility that water droplets due to dew will adhere between the pair of detection units 19c and 20c, the slit 69 does not necessarily need to be formed. In addition to the case where the slit 69 is not formed, the window on the bottom surface side of the insulating material 68 is not necessarily required even when the slit 69 is formed. Further, the insulating substrate 60 has a multilayer structure,
1 and 62 may be buried inside the substrate, and the connection conductor 62 may be eliminated and the detection section 19c and the detection circuit element 21 may be embedded.
Terminals 63 to 66 may be directly connected to a.

FIG. 10 is a diagram showing the configuration of the fourth embodiment of the water wetting sensor 18. The water wetness sensor 18d shown in FIG. 10 is different from the water wetness sensor 18d in that the insulating substrate 60 of the third embodiment shown in FIG. The other configuration is substantially the same as that of the third embodiment shown in FIG. 9. Therefore, the same components are denoted by the same reference numerals, and the description thereof will be omitted. The differences will be mainly described.

That is, in the water wetting sensor 18d, the pair of detecting portions 19c for detecting water wetting on the insulating substrate 60 and the connection conductors 62 connected to the detecting circuit element 21a extend to the same edge of the insulating substrate 60, respectively. The terminals 63 to 66 have a lead wire shape connected to the connection conductor 62 such that the terminals 63 to 66 extend in the same direction from one end edge of the insulating substrate 60 (so-called radial shape). . In the water wetting sensor 18d, the terminals 63 to 66 are inserted into the mounting holes of the printed wiring board 15 and connected to the wiring conductors of the printed wiring board 15 by means such as soldering. At a position near the substrate 60, a curved portion 63 for making the mounting hole self-supporting or the like.
1, 641, 651, 661 are formed. In addition,
Since the water wetting sensor 18d is mounted so that the insulating substrate 60 is substantially perpendicular to the printed wiring board 15, the protrusions 70 and 71 (FIG. 9) are not formed on the insulating material 68. .

The water wetting sensor 18d thus configured
Can be mounted on the printed wiring board 15 by using an automatic mounting machine equipped with a suction means and a gripping means, as in the case of other lead wire type electronic components, and the detection units 19c, 20c And so on, the occupied area on the printed wiring board 15 can be reduced.
Can be reliably detected. In addition, as a result of the mechanical strength of the insulating substrate 60 being increased due to the presence of the insulating material 68, the handling performance of the water wetness sensor 18d is improved, and even when mounted on the printed wiring board 15 by an automatic mounting machine, there is almost no risk of damage. There will be none. Further, the presence of the insulating material 68 makes it difficult for the insulating substrate 60 to be damaged even when stress is generated, and also protects the detection circuit element 21a from external pressure or the like, thereby improving the reliability of the water wetness sensor 18d. As a result, the operation reliability of the electronic control circuit 10 is also improved.

In any of the above embodiments,
The detection circuit element 2 which is an electronic component constituting the detection circuit 21 provided in the water wetting sensors 18a, 18b, 18c, 18d
Although 1a is an integrated circuit, the detection circuit 21 may be configured using a plurality of discrete electronic components. Also, in any of the above embodiments,
The detection circuit 21 provided in the water wetting sensors 18a, 18b, 18c, 18d does not have the latch circuit shown in FIG. 3, but each of the water wetting sensors 18a, 18b, 18c, 1
8d can also be configured as having a latch circuit.

[0071]

As described above, in the water wetting sensor according to the first aspect, a pair of detecting portions made of a conductive material facing each other at a predetermined interval, and water is interposed between the detecting portions to cause leakage. The base member holds a detection circuit that outputs a detection signal of a predetermined level when a current flows, and a terminal that is electrically connected to the detection unit and the detection circuit and that is connected to the wiring conductor of the electronic control circuit board. Therefore, the electronic control circuit can be easily mounted on a printed wiring board constituting the electronic control circuit, and the water wetting of the electronic control circuit can be reliably detected.

Further, in the water wetting sensor according to the second aspect,
Since the detection circuit includes an amplification circuit that amplifies a leak current flowing between the detection units, and an output circuit that outputs a detection signal of a predetermined level by amplifying the leakage current by the amplification circuit, a pair of the detection units is provided. As a result, a detection signal of a predetermined level is always output when a leak current flows, so that the water wetting of the electronic control circuit can be more reliably detected.

Further, in the water wetness sensor according to the third aspect,
The detection circuit has a latch circuit that continuously outputs a detection signal of a predetermined level even when the leakage current flowing between the detection units decreases or disappears. Even if the leak current decreases or disappears to the extent that it cannot be performed, the water wetting of the electronic control circuit can be reliably detected.

Further, in the water wetness sensor according to the fourth aspect,
The base member is formed of an insulating substrate, the detecting section is formed of a film conductor disposed on the insulating substrate, the terminal is formed of a metal member, and the detecting circuit is formed of an electronic component constituting the detecting circuit. Since the electronic component is mounted on the insulating substrate and connected to the detection unit and the terminal to form a circuit, assembly becomes easy and mass productivity is improved.

Further, in the water wetting sensor according to the fifth aspect,
Since the insulating substrate is covered with the insulating material with the pair of detection parts exposed to the outside, the mechanical strength of the insulating substrate is increased, the handling performance in an automatic mounting machine and the like is improved, and the insulating substrate is stressed. Even if the occurrence of occurs, it is hard to be damaged, and the detection circuit is also protected from external pressure and the like, so that the reliability is excellent.

Further, in the water wetting sensor according to claim 6,
The detection unit and the terminal are constituted by a metal plate disposed in the base member with at least one end exposed to the outside, and since the detection circuit is disposed in the base member, the detection unit and the terminal are rugged. Excellent handling performance in automatic mounting machines and the like.

Further, in the water wetness sensor according to claim 7,
The base member is formed of an insulating member formed by molding, and the detecting portion and the terminal are formed by ends exposed to the outside of the metal plate, and the electronic circuit constituting the detecting circuit is made of metal. Since the electronic component is mounted on a board and connected to the detection unit and the terminal to form a circuit, poor connection between the members is less likely to occur, and the operation reliability is excellent.

In the water wetness sensor according to claim 8,
Since a hollow portion is formed between the pair of detection portions, even if dew condensation occurs between the pair of detection portions, a minute amount of water droplets is absorbed in the slit and short-circuiting between the detection portions is prevented, It is possible to reliably detect only a wet state due to submersion or the like.

Further, in the water wetting sensor according to the ninth aspect,
Since the terminal has a surface mounting shape and is attached to the opposite edge of the base member, the terminal can be reliably surface mounted on the printed wiring board.

Further, in the water wetting sensor according to the tenth aspect, since the terminal has a lead wire shape and is attached to the opposite end edge of the base member so as to extend in opposite directions, the terminal is inserted into the attachment hole. By doing so, the base member can be reliably mounted on the printed wiring board in a horizontal state.

Further, in the water wetting sensor according to the eleventh aspect, since the terminal has a lead wire shape and is attached to the edge of the base member so as to extend in the same direction, the terminal is inserted into the attachment hole. Thereby, the base member can be mounted on the printed circuit board in a vertical state.

According to a twelfth aspect of the present invention, there is provided an electronic control circuit board having various electronic components constituting a control circuit and a water wetness sensor according to any one of the first to eleventh aspects mounted on a wiring board. It is possible to reliably detect the water wetting of the electronic control circuit by the water wetting sensor,
An appropriate control operation corresponding to the wet state can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of an electronic control circuit to which a water wetness sensor according to an embodiment of the present invention is applied.

FIGS. 2A and 2B are diagrams illustrating a configuration example of a detection circuit integrated with the water wetness sensor illustrated in FIG. 1; FIG.
FIG.

FIGS. 3A and 3B are diagrams showing another configuration example of a detection circuit integrated with the water wetting sensor shown in FIG. 1; FIG.
(B) is the block diagram.

4A and 4B are diagrams for explaining a state of a leak current flowing between detection units of the water wetting sensor shown in FIG. 1, wherein FIG. 4A is a characteristic diagram showing a relationship between a leak current and time, and FIG. 7 is a characteristic diagram showing a relationship between an output signal and time.

FIG. 5 is an external perspective view showing a configuration of a water wetness sensor according to the first embodiment applied to the electronic control circuit shown in FIG. 1;

6 is an external perspective view showing a modified example of the water wetting sensor shown in FIG.

FIG. 7 is an external perspective view showing a configuration of a water wetness sensor according to a second embodiment applied to the electronic control circuit shown in FIG. 1;

FIG. 8 is a view showing a modification of the water wetness sensor of the second embodiment shown in FIG. 7;

FIG. 9 is an external perspective view showing a configuration of a water wetness sensor according to a third embodiment applied to the electronic control circuit shown in FIG. 1;

FIG. 10 is an external perspective view showing a configuration of a water wetness sensor according to a fourth embodiment applied to the electronic control circuit shown in FIG. 1;

[Explanation of symbols]

18, 18a, 18b, 18c, 18d Water wetting sensor 19, 20, 19a, 20a, 19b, 20b, 19
c, 20c detection unit 30, 60 insulating substrate (base member) 32, 33, 48, 49, 51, 52, 53, 61, 6
2 Connection conductors 34, 35, 36, 37, 50, 54, 55, 56, 6
3, 64, 65, 66 terminals 38, 57, 69 Slits 40, 68 Insulating material 42, 43, 44, 45, 46 Metal plate 47 Insulating member (base member) 39, 67 Window

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshihiko Komatsu 1-7-10 Kikuzumi, Minami-ku, Nagoya City, Aichi Prefecture Inside Harness Research Institute, Inc. (72) Inventor Yukio Kawamura 1-Kikuzumi, Minami-ku, Nagoya City, Aichi Prefecture No. 7-10 Harness Research Institute, Inc. F-term (reference) 2G067 AA48 BB11 CC02 DD22 5E338 AA05 BB02 BB17 BB75 CC01 CD11 EE11

Claims (12)

[Claims] 1. A water wetting sensor mounted on an electronic control circuit board mounted on a vehicle and detecting water wetting of an electronic control circuit, comprising a pair of conductive materials opposing each other at a predetermined interval. A detection circuit for outputting a detection signal of a predetermined level when water leaks due to intervening water between the detection units; and the electronic control circuit board electrically connected to the detection unit and the detection circuit. And a terminal connected to the wiring conductor is held by a base member. 2. The detection circuit according to claim 1, further comprising: an amplification circuit configured to amplify a leakage current flowing between the detection units, and an output circuit configured to output a predetermined level detection signal by amplifying the leakage current in the amplification circuit. The water wetting sensor according to claim 1, wherein: 3. The detection circuit according to claim 2, further comprising: a latch circuit that continuously outputs a detection signal of a predetermined level even when a leakage current flowing between the detection units decreases or disappears. Water wetting sensor as described. 4. The detection circuit, wherein the base member is formed of an insulating substrate, the detecting section is formed of a film conductor provided on the insulating substrate, and the terminal is formed of a metal member. 4. The electronic device according to claim 1, wherein an electronic component forming the detection circuit is mounted on the insulating substrate, and the electronic component is connected to a detection unit and a terminal to form a circuit. Water wetting sensor. 5. The sensor according to claim 4, wherein the insulating substrate is covered with an insulating material in a state where the pair of detecting portions are exposed to the outside. 6. The detection section and the terminal are constituted by a metal plate disposed in the base member with at least one end thereof exposed to the outside, and the detection circuit is disposed in the base member. The water wetting sensor according to claim 1, wherein the sensor is provided. 7. The base member is constituted by an insulating member formed by molding, and the detection section and the terminal are formed by ends exposed to the outside of the metal plate. 7. An electronic component constituting a detection circuit is mounted on the metal plate, and the electronic component is connected to a detection unit and a terminal to form a circuit.
Water wetting sensor as described. 8. The water wetness sensor according to claim 1, wherein a hollow portion is formed between the pair of detection portions. 9. The water wet sensor according to claim 1, wherein the terminal has a surface mounting shape, and is attached to a facing edge of the base member. 10. The terminal according to claim 1, wherein the terminal has a lead wire shape, and is attached to opposite edges of the base member so as to extend in mutually opposite directions. Water wetting sensor. 11. The water according to claim 1, wherein the terminal has a lead wire shape and is attached to an edge of the base member so as to extend in the same direction. Wetting sensor. 12. An electronic control circuit board mounted on a vehicle, wherein various electronic components constituting a control circuit and a water wetness sensor according to claim 1 are mounted on a wiring board. An electronic control circuit board provided with a water wetness sensor having a circuit configuration.