JP6413252B2 - Water leakage detection device - Google Patents

Description

  The present invention relates to an apparatus for detecting water leakage in electronic equipment. More specifically, the present invention relates to a water leakage detection device and the like that can detect water leakage with high accuracy with a simple configuration for circuit boards and the like.

  In recent years, due to the integration of semiconductor circuits, the amount of heat generated by devices such as large-scale integrated circuits has increased.

  As measures against such an increase in the amount of heat generation, for example, there are increasing cases in which a water-cooled cooling device (hereinafter sometimes referred to as a “water-cooled unit”) that can cool the device by water cooling is used.

  For example, when such a water cooling unit is used for cooling a CPU (Central Processing Unit), one of the most serious accidents is a water leakage accident from the water cooling unit. The CPU is the most important member in the information processing apparatus, and it is necessary to take strict measures against a water leakage accident that may damage the CPU.

  In many cases, the water cooling unit itself takes measures against water leakage so as not to cause a water leakage accident. However, depending on the situation, water leakage may occur, and it may be difficult to completely prevent water leakage.

  Thus, there is a need for a water leakage detection device that can detect the occurrence of water leakage with high accuracy and early so that damage from a water leakage accident can be prevented or reduced.

  As a related technique regarding such a water leakage detection apparatus, there are the following patent documents, for example.

  Patent Document 1 discloses a technique related to a water leakage detection line in which two conductors are each wrapped with water-absorbing paper and arranged in a continuous manner. According to the water leak detection line disclosed in Patent Document 1, when water leaks, the moisture that has penetrated into the water absorbent paper changes the electrical resistance between the two conductors. It is possible to detect.

  Patent document 2 discloses the technique regarding the sheet-like water leak detection sensor which can be cut | disconnected as needed. The water leakage sensor disclosed in Patent Document 2 is formed in a layered structure in which a first electrode line, a water retention sheet, a second electrode line, and a water permeable protective sheet are sequentially laminated on a long base sheet, The first and second electrode lines are arranged vertically and horizontally so as to form a substantially mesh shape. When water leakage occurs, the moisture permeated through the water-permeable protective sheet is absorbed by the water-retaining sheet, and the resistance value is changed by short-circuiting the first and second electrode wires. The water leakage sensor disclosed in Patent Document 2 detects water leakage based on the change in the resistance value.

  Patent document 3 discloses the technique regarding the water leak detection apparatus which uses a water absorption expansion | swelling member. The water leak detector disclosed in Patent Document 3 includes a container that houses a water absorbing expansion member, and an electrical switch mechanism that opens and closes by moving an electrode or a short-circuit conductor due to expansion of the water absorbing expansion member. When water leakage occurs, the water absorption expansion expands by absorbing moisture, thereby opening and closing the electrical switch. The water leak detector disclosed in Patent Document 2 detects water leak by opening and closing the electrical switch.

Utility model registration No. 3094002 JP 2006-101282 A JP 2006-078389 A

  Here, for example, when water leakage is detected in the above-described water cooling unit or the like, a water leakage detection device may be provided on the circuit board. Such a water leakage detection device is required to detect water leakage with high accuracy and easily while having a relatively simple configuration that can be mounted on a circuit board.

  The techniques disclosed in Patent Document 1 and Patent Document 2 are both appropriate standards (for example, appropriate threshold values) for determining water leakage depending on the situation, such as the degree of wetness associated with water absorption of water-absorbing paper or water-retaining sheets. Etc.) must be set.

  If these settings are inappropriate, problems such as detection without false water leakage (false positive), or leakage but no detection (false negative) may occur. In addition, a non-conductive liquid widely used as a medium (refrigerant) such as a water cooling unit may not short-circuit between conductors even if water leaks, and may not detect water leak.

  Since the technique disclosed in Patent Document 3 detects water leakage using an electrical switch, it is not essential to set a reference value for determining water leakage, and it can be considered to be compatible with various liquids. However, the water leakage detection device disclosed in Patent Document 3 is not suitable for mounting on a circuit board, for example, because the dimensions (size) of the components that resist the water leakage detection device are relatively large. . Further, none of the water leak sensors disclosed in Patent Documents 1 to 3 considers a waterproof structure by the water leak sensor itself.

  In addition to the above, for example, a water leakage detection device based on an optical sensor method using reflection of moisture light is well known, but the device becomes large and may not be suitable for mounting on a circuit board.

  The present invention has been made in view of the above circumstances. That is, the main object of the present invention is to provide a water leakage detection device that can detect water leakage with a relatively simple configuration with high accuracy.

  In order to achieve the above object, a water leakage detection apparatus according to the present invention is characterized by having the following configuration. That is, the water leakage detection device according to the present invention includes a pressure-sensitive sensor capable of detecting a pressing force on a surface where the device is installed, a water-permeable sheet formed of a material that allows moisture to pass through, and the pressure-sensitive sensor. And a plurality of water-absorbing expansion members formed of a material that absorbs moisture and expands in volume, and in a first state in which the water-absorbing expansion member is not expanded, A fixing member that maintains a constant or substantially constant interval between the sheet and the pressure-sensitive sensor, and sequentially from the pressure-sensitive sensor, the water-absorbing expansion member, the water-permeable sheet, or the installation surface side. Based on the pressing force due to expansion of the water absorbing expansion member detected by the pressure sensor in the second state where the water absorbing expansion member is expanded by absorbing water, the leakage of water is generated. Detection And wherein the Rukoto.

  According to the present invention, it is possible to provide a water leakage detection device that can easily detect the occurrence of water leakage with high accuracy.

FIG. 1 is a perspective view illustrating a part of a water leakage detection device according to the first embodiment of the present invention by being broken. FIG. 2 is a diagram illustrating a part of the AA cross-sectional view of FIG. 1. FIG. 3 is a perspective view illustrating the arrangement of the water leakage detection unit in the water leakage detection device according to the first embodiment of the present invention. FIG. 4 is an enlarged view illustrating a part of the water leakage detection unit according to the first embodiment of the present invention. FIG. 5 is a diagram illustrating the arrangement of electrode wires constituting the water leakage detection unit according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view illustrating a case where the water absorbing / expanding member is expanded in the water leakage detection device according to the first embodiment of the present invention. FIG. 7: is sectional drawing which illustrates the case where the water absorption expansion member expand | swells in the water leak detection apparatus which concerns on 2nd Embodiment of this invention. FIG. 8 is a perspective view illustrating the state of the water leakage detection unit when the water absorption expansion member is expanded in the water leakage detection device according to the second embodiment of the present invention. FIG. 9 is a perspective view illustrating a part of the water leakage detection device according to the third embodiment of the present invention by breaking it. FIG. 10 is a diagram illustrating a part of the BB cross-sectional view of FIG. 10. FIG. 11 is an exploded view illustrating a specific configuration of a pressure-sensitive sensor according to the third embodiment of the present invention. FIG. 11 is a cross-sectional view illustrating a specific configuration of a pressure-sensitive sensor according to the third embodiment of the present invention. FIG. 13 is a cross-sectional view illustrating the configuration of a pressure-sensitive sensor when the water-absorbing / expanding member is inflated according to the third embodiment of the present invention.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. The configurations described in the following embodiments are merely examples, and the technical scope of the present invention is not limited thereto.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a diagram illustrating a part of the AA sectional view in FIG. 1.

  As illustrated in FIG. 1, the water leakage detection apparatus 100 according to the present embodiment includes a moisture-impermeable sheet 101, a first electrode line 102 and a second electrode line 103 that constitute a pressure-sensitive sensor described later, and water absorption. The expansion member 104, the fixing member 105, and the water permeable sheet 106 are included. The water leakage detection circuit 100 in the present embodiment is formed such that the above-described constituent members form a layer with respect to the installation surface. In the present embodiment, the installation surface may be a circuit board, for example. Hereinafter, each component will be described.

  The moisture-impermeable sheet 101 is a sheet-like member made of a material that does not transmit moisture, and is placed on an installation surface such as a circuit board. The moisture-impermeable sheet 101 may be made of, for example, a resin processed into a sheet shape, a waterproof cloth that has been waterproofed, or the like. In addition, when the ground plane on which the moisture impermeable sheet 101 is placed is a circuit board, the moisture impermeable sheet 101 is made of an insulating material in order to prevent a short circuit of a circuit pattern or various elements. It may be configured.

  In the present embodiment, the moisture impermeable sheet 101 and the installation surface may be appropriately fixed by an appropriate method. For example, the moisture impermeable sheet 101 and the installation surface may be bonded with an adhesive or the like, or may be fixed with a fixing member such as a screw.

  By disposing the moisture-impermeable sheet 101 as described above, it is possible to prevent moisture from propagating to an installation surface such as a circuit board even when water leakage occurs.

  Each of the first electrode line 102 and the second electrode line 103 is a wiring member made of a conductor such as metal. As illustrated in FIG. 2, the first electrode line and the second electrode line are in a state where a water-absorbing expansion material 104 described later is not expanded (hereinafter, sometimes referred to as “first state”). , And are arranged in a non-contact manner with a gap d. In addition, what is necessary is just to set the space | gap d appropriately suitably according to the amount of volume changes accompanying the water absorption in the water absorbing expansion material 104 mentioned later.

  In the present embodiment, the second electrode line 103 may be supported by a support member (not shown) or the like so as to be separated from the first electrode line 102. In the present embodiment, since a method of arranging the first electrode line and the second electrode line in a non-contact manner may be appropriately selected as appropriate, detailed description thereof is omitted.

  In the present embodiment, the first electrode line 102 and the second electrode line 103 are arranged so as to intersect three-dimensionally with a predetermined angle θ, as illustrated in FIGS. 2 to 4. Hereinafter, in the present embodiment, the three-dimensionally intersecting portion may be referred to as “intersection”.

  In the present embodiment, the first electrode line 102 and the second electrode line 103 have, for example, a plurality of intersecting portions as illustrated in FIG. 3 so as to form a substantially mesh shape as a whole. It may be arranged. In this case, for example, as illustrated in FIG. 5, the first electrode line and the second electrode line are each formed in a comb shape, and these are overlapped in a non-contact manner to form a mesh shape as illustrated in FIG. 3. May be formed. Note that the present embodiment is not limited to this, and the first electrode line 102 and the second electrode line 103 or any shape having an intersection may be adopted.

  When a pressing force is applied to at least one of the first electrode line 102 and the second electrode line 103 formed as described above, these electrode lines come into contact (short circuit) with each other. As a result, the electrical resistance between these electrode lines changes. For example, compared with the case where the first electrode line 102 and the second electrode line 103 are arranged in a non-contact manner, the electrical resistance value between the electrode lines is lower when these electrode lines are in contact with each other. And between these electrode lines will be in a conduction state. That is, the first electrode line 102 and the second electrode line 103 in the present embodiment detect a change in a conduction state between the electrode lines (that is, on / off of an electrical switch) according to the pressing force. Functions as a pressure sensitive sensor. Hereinafter, in the present embodiment, the first electrode line 102 and the second electrode line 103 may be collectively referred to as a “pressure sensor”.

  In the present embodiment, the first electrode line 102 and the second electrode line 103 may include sensor lead wires 102a and 103a for detecting the opening / closing of the electrical switch described above.

  In the present embodiment, on / off of an electrical switch may be output from the sensor lead wire as the output of the pressure sensitive sensor. Further, the water leakage detection device 100 in the present embodiment measures the resistance value between the first electrode line 102 and the second electrode line 103 from the sensor lead wire, and the change in the resistance value The electrical switch may be turned on or off. In addition, this embodiment is not limited to this, The water leak detection apparatus 100 in this embodiment measures the resistance value between the said 1st electrode line 102 and the 2nd electrode line 103, for example, and concerns Based on the change in the resistance value, the presence or absence of water leakage may be determined by an arbitrary criterion.

  In the present embodiment, the water leakage detection device 100 may include a water leakage determination unit (not shown) that determines the presence or absence of water leakage from the output of the pressure sensor described above and outputs the determination result.

  The pressure sensor as described above has, for example, a dimension (reference numeral H1 in FIG. 2, hereinafter referred to as “pressure sensor thickness”) in a direction perpendicular to the installation surface illustrated in FIG. It is also possible to form a film of about 1 [mm (millimeter)]. In addition, the pressure sensor formed in this way can sense a pressure of about 2 [kPa (kilopascal)], for example.

  Further, the pressure-sensitive sensor, for example, as illustrated in FIG. 2, covers a member that resists the pressure-sensitive sensor (second electrode wire in the specific example illustrated in FIG. 2). You may have. In addition to the first electrode line 102, the second electrode line 103, and the covering sheet 201, the pressure-sensitive sensor includes an arbitrary protective sheet and a support member that supports the above-described second electrode line 103. You may further have arbitrary additional structures, such as (all are not shown).

  The water-absorbing expansion material 104 is made of a water-absorbing material that expands by absorbing moisture, such as a highly water-absorbing resin. As the water-absorbing material constituting the water-absorbing expansion material 104, for example, a material having the following features (i) to (iii) can be employed.

  (I) The water-soluble polymer has a three-dimensional network structure that is appropriately crosslinked.

  (Ii) Although it is possible to absorb approximately several hundred times to 1,000 times as much water as the weight in a state where water is not absorbed, it is essentially insoluble in water.

  (Iii) Moisture once absorbed does not separate even if some pressure is applied.

  For example, the specific water absorption time per 0.1 g of known water-absorbing material is 20 seconds for water 5 [ml (milliliter)], 60 seconds for water 10 [ml], and for water 300 [ml]. About 180 seconds.

  Examples of such well-known water-absorbing materials include “Sunwet” (registered trademark) and “Aquapearl” (registered trademark), which are products of Sanyo Chemical Industries, Ltd. In addition, in this embodiment, it is not limited to these illustrated materials, Arbitrary water absorption materials provided with the characteristics of said (i) thru | or (iii) may be employ | adopted.

  Further, for example, a water-absorbing material such as a highly water-absorbing resin expands in a spherical shape by the amount of the absorbed liquid. For example, when moisture 0.05 [ml] (about one drop) is converted into a sphere volume, the radius of the sphere is about 0.2 [mm]. For this reason, even if a superabsorbent resin absorbs a very small amount of water, the volume expands by the amount of absorbed water.

  As illustrated in FIGS. 2 to 4, for example, at least a part of the water-absorbing / expanding material 104 according to the present embodiment covers the intersection between the first electrode line 102 and the second electrode line 103. May be arranged as follows. In addition, when there are a plurality of the intersections, the water-absorbing and expanding material 104 in the present embodiment may be individually provided for each intersection, and at least a part of the water-absorbing and expanding material 104 covers the plurality of intersecting parts. It may be provided.

  The water-absorbing expansion material 104 in the present embodiment is fixed between a water-permeable sheet 106 described later and a pressure-sensitive sensor. More specifically, the water-absorbing and expanding material 104 in the present embodiment is, for example, a lower surface of a water-permeable sheet 106 described later (a surface facing the installation surface, a lower side in FIG. 2), or an upper surface of the pressure-sensitive sensor ( It may be fixed to any one of the surface facing the water permeable sheet 106 and the upper side of the drawing in FIG.

  In this case, the water-absorbing expansion material 104 may be fixed by an adhesive or the like at 104a which is a contact portion with the water-permeable sheet 106, for example. The present embodiment is not limited to the above, and the water-absorbing expansion material 104 may be fixed using an appropriate method as appropriate.

  The water-absorbing and expanding material 104 in the present embodiment arranged as described above absorbs moisture and expands (hereinafter sometimes referred to as “second state”). Part) presses the intersection. In this way, when the intersecting portion is pressed in the second state, the second electrode line 103 and the first electrode line 102 that constitute the pressure-sensitive sensor come into contact with each other, and the first electrode line 102 and The resistance value between the second electrode line 103 decreases.

In the present embodiment, the water-absorbing and expanding material 104 has a dimension (reference numeral AH in FIG. 2, hereinafter referred to as “height dimension of the water-absorbing and expanding material 104”) with respect to the direction perpendicular to the installation surface. The cross section may be formed to have a substantially elliptical shape that is smaller than the dimension with respect to the direction (reference numeral AW in FIG. 2, hereinafter sometimes referred to as “width dimension of the water-absorbing and expanding material 104”).
When formed in this way, in the second state, the water-absorbing and expanding material 104 expands in the height direction perpendicular to the installation surface, so that the pressure-sensitive sensor can be effectively pressed.

  Further, the water-absorbing and expanding material 104 in the present embodiment may be formed in a substantially spherical shape, and in this case, the cross-sectional shape in a direction perpendicular to the installation surface is a substantially circular shape. When formed in this manner, the pressure-sensitive sensor can be effectively pressed by the water absorbing / expanding material 104 expanding substantially uniformly in the second state.

  In the following description, the pressure sensor and the water-absorbing / expanding material 104 disposed so as to be able to press the pressure sensor may be collectively referred to as a “leak detector”.

  The fixing member 105 is made of, for example, a filler having an adhesive force, and fixes a water-permeable sheet 106 described later.

  For example, as illustrated in FIG. 1, the fixing member 105 in the present embodiment has a predetermined interval inside the mesh formed by the first and second electrode wires (102, 103) constituting the pressure-sensitive sensor. May be installed. Moreover, you may install in the peripheral part of the said pressure sensitive sensor.

  The fixing member 105 in the present embodiment is, for example, on one end side so that the distance between the lower surface of a water-permeable sheet 106 described later and the upper surface of the pressure sensor (reference numeral H2 in FIG. 2) is constant or substantially constant. The water-permeable sheet 106 is fixed to (reference numeral 105a in FIG. 2), and the other end side (reference numeral 105b in FIG. 2) is fixed to the moisture-impermeable sheet 101.

  In the present embodiment, the one end side 105a of the fixing member 105 and the water permeable sheet 106 may be fixed by an appropriate fixing method such as an adhesive. Similarly, the other end side 105b of the fixing member 105 and the moisture-impermeable sheet 101 may be fixed by an appropriate fixing method such as an adhesive. In this case, as the adhesive, for example, an adhesive having an adhesive strength that does not peel from the water-permeable sheet in the second state in which the water-absorbing and expanding material 104 has expanded by absorbing moisture may be employed. .

  The other end side 105b of the fixing member 105 has a constant or substantially constant distance H2 between the lower surface of the water-permeable sheet 106 and the upper surface of the pressure-sensitive sensor in the first state where the water-absorbing expansion material 104 is not expanded. It may be fixed to an arbitrary member that can be kept at the same position. More specifically, the other end side 105b of the fixing member 105 may be fixed to, for example, an installation surface or an upper surface of the pressure sensor.

  The water permeable sheet 106 is a sheet-like or film-like member having water permeability. In the present embodiment, for example, the water permeable sheet 106 may be configured by a resin film or sheet provided with a penetrating portion through which moisture can permeate, or a woven or nonwoven fabric having water resistance.

  For example, the inner surface (surface on the installation surface side) of the water permeable sheet 106 may be fixed to one end 105 a of the fixing member 105. Further, for example, a water absorbent expansion material 104 may be fixed to the water permeable sheet 106 at the contact portion 104a on the inner surface (surface on the installation surface side) of the water permeable sheet 106.

  In the present embodiment, moisture (for example, leaked liquid) adhering to the upper surface (surface opposite to the installation surface) of the water permeable sheet 106 passes through the water permeable sheet 106 and is absorbed by the water absorbent expansion material 104.

  The operation of the water leakage detection device configured as described above to detect water leakage will be described with reference to FIG. 6 illustrates a configuration in which some components are removed from the drawing illustrated in FIG. 2 for convenience of explanation.

  First, in the situation where no water leakage occurs, as illustrated in FIG. 2, the water absorbing / expanding material 104 is not expanded (the first state) and does not press the pressure sensitive sensor. In this case, the resistance value at the output end (for example, 102a, 103a, etc.) of the pressure sensor is large. In this case, the water leakage detection device 100 in this embodiment determines that no water leakage has occurred.

  As illustrated in FIG. 6, in the present embodiment, for example, the leaked liquid 601 (for example, the cooling liquid of the water cooling unit) permeates the water permeable sheet 106 and is absorbed by the water absorbent expansion material 104.

  The volume of the water-absorbing expansion material 104 that has absorbed the liquid 601 expands (the second state), and the pressure-sensitive sensor is pressed by the pressure accompanying the expansion (reference P1 in FIG. 6). In this case, the resistance value at the output end (for example, 102a, 103a, etc.) of the pressure sensor becomes small. In this case, the water leakage detection device 100 in the present embodiment determines that water leakage has occurred.

  More specifically, in the second state in which moisture is absorbed, the water-absorbing expansion material 104 is, for example, at least one of the first electrode line 102 and the second electrode line 103 that constitute the pressure-sensitive sensor. Press. In the specific example illustrated in FIG. 6, the water absorbent expansion material 104 presses the second electrode wire 103 at the intersection, for example.

  In the present embodiment, the fixing member 105 fixes the water permeable sheet 106 so that the distance H2 between the water permeable sheet 106 and the pressure sensor is kept constant or substantially constant. Moreover, the water absorbing expansion material 104 is fixed between the pressure-sensitive sensor and the water-permeable sheet 106 as described above. Further, in the present embodiment, the fixing member 105 and the water-permeable sheet 106 are fixed so as not to be peeled even in the second state in which the water-absorbing / expanding material 104 has absorbed moisture (reference numeral P2 in FIG. 6).

  For this reason, the pressure accompanying expansion | swelling of the water absorbing expansion material 104 can satisfy | fill the pressure required as a switch which presses the said pressure sensor. That is, the expansion pressure in the second state in which the water-absorbing expansion material 104 has absorbed moisture is configured to face the electrode direction, and the pressure-sensitive sensor is pressed by the expansion pressure.

  The pressure-sensitive sensor may output the opening / closing of an electrical switch based on, for example, a change in electrical resistance value associated with the pressing. Moreover, the water leak detection apparatus 100 may determine the presence or absence of water leak based on a specific reference | standard by measuring resistance value in the output terminal (for example, 102a, 103a etc.) of the said pressure sensitive sensor.

  In the present embodiment, it is possible to cause the water leak detection device 100 to function as a simple waterproof (drip-proof) cover using the property that the water-absorbing expansion material 104 absorbs moisture. When water leakage occurs, if the amount of leaked water is small, most of the water that the water absorbing / expanding material 104 absorbs can be absorbed, and the water to be protected (for example, the circuit board that is the installation surface) Wet damage can be reduced.

  Furthermore, the water leak detection apparatus 100 in the present embodiment includes the moisture impermeable sheet 101 as described above. For this reason, for example, the function as a simple waterproof cover of the water leak detection device 100 can be realized by complementing the waterproof function by the water impermeable sheet 101 with the water absorption function by the water absorbing expansion material 104. . Further, when the covering sheet 201 described above is made of a waterproof material that has flexibility and does not allow moisture to permeate, the combination of the water-absorbing expansion material 104, the covering sheet 201, and the moisture-impermeable sheet 101, It is possible to improve waterproof performance.

  According to the water leak detection device 100 in the present embodiment configured as described above, even if a small amount of the water absorbing / expanding material 104 is used, the pressure sensitive sensor can be sufficiently pressed by absorbing water and expanding. .

  Further, as described above, it is possible to reduce the thickness of the pressure-sensitive sensor itself in the present embodiment, and the water-absorbing expansion material 104 and the components constituting the pressure-sensitive sensor are relatively made from known members and the like. It can be procured at low cost. For this reason, according to the water leak detection apparatus 100 in this embodiment, it is thin and does not become an obstacle at the time of installation, and it becomes possible to detect water leak at a low cost over a wide area.

  Further, as described above, according to the water leakage detection device 100 in the present embodiment, the water leakage is determined by detecting the change in the resistance value of the pressure-sensitive sensor accompanying the expansion of the water-absorbing expansion material 104. For this reason, it is possible to reliably detect a change in resistance value due to pressing, and to accurately detect water leakage.

  In particular, when the pressure sensor outputs on / off of an electrical switch accompanying expansion of the water-absorbing expansion material 104, the presence or absence of water leakage can be converted into a digital value. For this reason, for example, it is possible to raise detection accuracy with respect to the water leak determination based on the analog value called the insulation resistance value as disclosed in Patent Document 1 and Patent Document 2 described above.

  Furthermore, according to the water leakage detection device 100 in the present embodiment, the water leakage detection device 100 itself functions as a simple waterproof cover, thereby preventing water from entering the installation surface.

  For this reason, according to the water leak detection apparatus 100 in the present embodiment configured as described above, as described above, the water leak is detected with high accuracy by a relatively simple configuration using the pressure-sensitive sensor and the water absorbing expansion material. Is possible.

  In addition, the water leak detection apparatus 100 in the present embodiment configured as described above can be applied to, for example, the purpose of detecting water leak from a water cooling unit that cools an integrated circuit provided on a circuit board.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. In the following description, the characteristic parts according to the present embodiment will be mainly described, and the same reference numerals will be given to the same configurations as those in the first embodiment described above, and the redundant description will be omitted. To do.

  The leak detection device in the present embodiment is different from the leak detection device illustrated in FIG. 1 only in the arrangement of the water-absorbing expansion material, and other components may be equivalent. Hereinafter, the difference will be described.

  As illustrated in FIGS. 7 and 8, the water absorbing / expanding material 104 according to the present embodiment has at least one specific water absorbing / expanding material 104 and another water absorbing / expanding material 104 in the second state in which moisture is absorbed. It arrange | positions with the space | interval which contacts in a part. Further, the respective water-absorbing expansion materials 104 may be disposed so as to be in close contact with each other in the second state in which moisture is absorbed.

  More specifically, the water-absorbing / expanding material 104 in the present embodiment may be disposed at intervals that allow the surface parallel to the installation surface to be filled by the respective water-absorbing / expanding materials 104 expanded in the second state. Good. In other words, the water-absorbing / expanding material 104 may be arranged at an interval that allows the installation surface to be covered by the plurality of water-absorbing / expanding materials 104 expanded in the second state.

  In the specific example illustrated in FIG. 7 and FIG. 8, each water-absorbing expansion material 104 that has absorbed water and expanded in the second state is in contact with the other water-absorbing expansion material 104 at the contact portion 701.

  In this case, the respective water-absorbing and expanding materials 104 may be disposed adjacent to each other in the first state or may be disposed adjacent to each other with a predetermined interval. The intervals at which the water-absorbing and expanding materials 104 are arranged may be appropriately determined according to the properties of the water-absorbing and expanding materials 104, such as how much the water-absorbing and expanding materials 104 expand when they absorb water. .

  When each water absorbing / expanding material 104 is arranged as described above, the gap between the water absorbing / expanding materials 104 in the second state is narrowed. Further, since the water-absorbing / expanding material 104 is in close contact with each other, a part of the installation surface is covered with the water-absorbing / expanding material 104 so that there is almost no gap.

  For this reason, most of the leaked water is absorbed and blocked by the layer in which the water-absorbing expansion material 104 is disposed, so that the water leak detection device 100 can function as a simple waterproof (drip-proof) cover.

  As mentioned above, according to the water leak detection apparatus in this embodiment, while exhibiting an effect equivalent to the said 1st Embodiment, water leak detection is carried out by the clearance gap between each water absorption expansion | swelling material 104 which absorbed and expanded | swelled moisture narrowing. The device 100 itself functions as a simple waterproof cover. For this reason, according to the water leak detection apparatus in the present embodiment, it is possible to more effectively prevent water from entering the installation surface.

<Third Embodiment>
Next, a configuration common to the above-described embodiments will be described as a third embodiment of the present invention with reference to FIGS. 9 to 13. FIG. 10 is a diagram illustrating a part of the BB cross-sectional view in FIG. 9.

  The water leakage detection device in the present embodiment includes a pressure sensor 901, a water permeable sheet 902, a water absorbing / expanding portion 903, and a fixing member 105. In addition, the water leakage detection device in the present embodiment may include a moisture impermeable sheet 905.

  The pressure sensor 901 is a sensor member capable of detecting a pressing force. As such a pressure-sensitive sensor, for example, a pressure-sensitive sensor configured by the first electrode line 102 and the second electrode line 103 described in the first embodiment may be used.

  In addition, this embodiment is not limited to this, For example, you may employ | adopt a pressure sensor as illustrated in FIG. 11 thru | or FIG.

  The pressure-sensitive sensor illustrated in FIG. 11 includes an electrode line 1102 and an electrode line 1103, and a conductive sheet 1101 is disposed at a predetermined interval so as to face the electrode line. The conductive sheet 1101 may have a conductive portion 1101a.

  As illustrated in FIGS. 12 to 13, the pressure-sensitive sensor configured as described above is configured such that the conductive portion 1101 a in the conductive sheet 1101 is pressed and the electrode wire 1102 The electrode wire 1103 is short-circuited. The pressure-sensitive sensor configured as described above may determine whether the electrical switch is on or off based on the side of the electrical resistance value associated with the short circuit. Moreover, the water leakage detection apparatus 900 in this embodiment measures the resistance value between the electrode wire 1102 and the electrode wire 1103, for example, and determines the presence or absence of water leakage according to an arbitrary criterion based on the change in the resistance value. May be.

  The water permeable sheet 902 is a sheet-like or film-like member having water permeability. The water permeable sheet 902 in the present embodiment may have the same configuration as the water permeable sheet 106 in the first embodiment.

  The water absorption expansion part 903 is comprised with the water absorption raw material which absorbs a water | moisture content and expands, for example like a highly water absorbent resin, and a volume increases. Moreover, the water absorption expansion part 903 in this embodiment is arrange | positioned between the said pressure sensitive sensor 901 and the said water-permeable sheet 902. FIG. In addition, the water absorption expansion part 903 in this embodiment is good also as a structure equivalent to the water absorption expansion part 104 in the said 1st Embodiment.

  The fixing member 904 maintains a constant interval between the water-permeable sheet 902 and the pressure-sensitive sensor 901 in the first state where the water-absorbing / expanding portion 903 is not expanded. Note that the fixing member 904 in the present embodiment may have the same configuration as the fixing member 105 in the first embodiment.

  The water-permeable sheet 902 is fixed to one end of the fixing member 904 in the present embodiment. Note that the other end side of the fixing member 904 in the present embodiment maintains a constant interval between the water-permeable sheet 902 and the pressure-sensitive sensor 901 in the first state where the water-absorbing / expanding portion 903 is not expanded. Affixed to any possible member. For example, the other end side of the fixing member 904 in the present embodiment faces the installation surface, the upper surface of the pressure-sensitive sensor 901 (the surface facing the water-permeable sheet 902), or the upper surface of the impermeable sheet 905 (the water-permeable sheet 902). Surface) or the like.

  The water leakage detection device 900 in the present embodiment is formed so as to form layers sequentially from the pressure-sensitive sensor 901, the water-absorbing / expanding member 903, the water-permeable sheet 902, or the installation surface side.

  Further, the water leakage detection device 900 according to the present embodiment is based on the pressing force due to the expansion of the water-absorbing expansion material 903 detected by the pressure-sensitive sensor 901 in the second state in which the water-absorbing expansion material 903 absorbs moisture and expands. To detect the occurrence of water leakage.

  Moreover, you may have the water-impermeable sheet | seat 905 between the water leak detection apparatus 900 in this embodiment, the installation surface, and the pressure sensor 901. FIG. In addition, this embodiment is not limited to this, For example, you may provide the water-impermeable sheet | seat 905 in the upper surface (surface facing the water-permeable sheet 902) of the pressure sensor 901. FIG. In the present embodiment, a moisture-impermeable sheet 905 may be provided in an arbitrary layer between the upper surface of the installation surface (the surface facing the water-permeable sheet 902) and the water-permeable sheet 902.

  According to the water leakage detection device of the present embodiment configured as described above, the pressure-sensitive sensor 901 is pressed by the pressing force that accompanies the expansion by absorbing the water leaked from the water absorbing and expanding material 903. For example, the electrical resistance value of the pressure-sensitive sensor 903 changes due to such pressing, and thus the water leakage detection device in the present embodiment can detect water leakage based on the change in the electrical resistance value.

  For this reason, according to the water leak detection apparatus 100 in the present embodiment configured as described above, as described above, the water leak is detected with high accuracy by a relatively simple configuration using the pressure-sensitive sensor and the water absorbing expansion material. Is possible.

  Moreover, according to the water leakage detection device 900 in the present embodiment, for example, the water absorption expansion unit 903 absorbs the water leaked, whereby the water leakage detection device itself functions as a simple waterproof cover and prevents water from entering the installation surface. It is possible.

  For this reason, according to the water leak detection apparatus 100 in the present embodiment configured as described above, as described above, the water leak is detected with high accuracy by a relatively simple configuration using the pressure-sensitive sensor and the water absorbing expansion material. Is possible.

  In the above, this invention was demonstrated as an example applied to exemplary embodiment mentioned above. However, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to such embodiments. In such a case, a new embodiment to which such changes or improvements are added can also be included in the technical scope of the present invention. This is clear from the matters described in the claims.

  The present invention is applicable as a device for detecting water leakage in electronic equipment. More specifically, the present invention can be applied to a water leakage detection device or the like that can detect water leakage with high accuracy with a simple configuration for circuit boards and the like. Such a water leakage detection device can be applied to, for example, the purpose of detecting water leakage from a water cooling unit that cools an integrated circuit provided on a circuit board.

DESCRIPTION OF SYMBOLS 100 Water leak detection apparatus 101 Moisture impermeable sheet | seat 102 1st electrode wire 103 2nd electrode wire 104 Water absorption expansion material 105 Fixing member 106 Water permeable sheet 900 Water leak detection apparatus 901 Pressure sensor 902 Water permeable sheet 903 Water absorption expansion | swelling part 904 Fixing member 905 Moisture impervious sheet 1101 Conductive sheet 1102 Electrode wire 1103 Electrode wire

Claims (10)

On the installation surface where the device is installed,
A pressure-sensitive sensor capable of detecting the pressing force;
A water permeable sheet formed of a material that allows moisture to penetrate;
It is arranged between the pressure-sensitive sensor and the water-permeable sheet, is formed of a material that absorbs moisture and expands in volume, and covers the installation surface in a state where the volume expands by absorbing moisture. A plurality of water-absorbing expansion members arranged adjacent to each other at a possible interval;
In the first state where the water-absorbing expansion member is not expanded, a fixing member that maintains a constant or substantially constant interval between the water-permeable sheet and the pressure-sensitive sensor,
The pressure-sensitive sensor, the water-absorbing expansion member, and the water-permeable sheet are formed so as to sequentially form layers from the installation surface side,
In the second state in which the water absorbing expansion member expands by absorbing moisture, the pressure sensor detects the occurrence of water leakage by detecting the pressing force due to expansion of the water absorbing expansion member,
In the second state, a plurality of the water absorbing and expanding members expand to cover the installation surface. Between the pressure-sensitive sensor and the water-absorbing expansion member, the second moisture-impermeable sheet member that is flexible and does not allow moisture to pass therethrough is disposed,
By forming the pressure-sensitive sensor and the water-permeable sheet in a film shape, the entire apparatus is formed in a sheet shape that can be placed on a circuit board.
The water leakage detection device according to claim 1. The pressure sensor is
A first electrode wire;
A second electrode line having one or more intersecting portions intersecting the first electrode line in the first state and wired in a non-contact manner with the first electrode line;
Have
In the second state, the water-absorbing expansion member presses at least one of the first electrode line or the second electrode line to thereby form the first electrode line and the second electrode line. The water leakage detection device according to claim 1, wherein the gap is short-circuited. The water absorbing expansion member has at least a part of the water absorbing expansion member covering the intersection,
The short circuit between the first electrode wire and the second electrode wire by a part of the water absorbing and expanding member pressing the intersecting portion in the second state. 3. The water leakage detection device according to 3.   The fixing member is a member having adhesiveness with the water-permeable sheet fixed to one end, and in the first state, the interval between the water-permeable sheet and the pressure-sensitive sensor is set in the first state. The water leakage detection device according to claim 4, wherein the water absorption expansion member is held substantially the same as a height dimension in a direction perpendicular to the installation surface. Between the pressure-sensitive sensor and the installation surface, a first moisture-impermeable sheet member that does not allow moisture to pass through is disposed,
The one end of the fixing member is fixed to the first moisture-impermeable sheet member, and the water-permeable sheet is fixed to the other end of the fixing member. The water leakage detection device described in 1.   In a cross section perpendicular to the installation surface on which the device is installed, the height of the water-absorbing expansion member in the direction perpendicular to the installation surface in the first state is horizontal to the installation surface in the first state. The water leakage detection device according to any one of claims 1 to 6, wherein the water leakage detection device is smaller than a width dimension of the water absorption expansion member with respect to a specific direction.   In the second state, each of the water absorbing / expanding members that has expanded by absorbing moisture contacts the water absorbing / expanding member that has expanded by absorbing other moisture at least at a part of the expansion surface of the water absorbing / expanding member. The water leakage detection device according to any one of claims 1 to 7, wherein each of the water absorption and expansion members is arranged adjacent to each other so as to cover the installation surface.   In the second state, the water-absorbing / expanding members are arranged adjacent to each other so that the plurality of water-absorbing / expanding members that have expanded by absorbing moisture are in close contact with each other and fill a plane parallel to the installation surface. The water leakage detection device according to any one of claims 1 to 8, wherein the water leakage detection device is characterized in that: The pressure sensor is
A third electrode wire;
A fourth electrode line disposed in non-contact with the third electrode line;
In the first state, at least one of the third electrode line or the fourth electrode line and a conductive sheet disposed in a non-contact manner,
In the second state, the water absorbing and expanding member that has expanded by absorbing moisture presses at least one of the third electrode line, the fourth electrode line, or the conductive sheet. The water leakage detection device according to claim 1, wherein the third electrode line, the fourth electrode line, and the conductive sheet are electrically connected.