JP2011152501A - Electrostatic atomizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic atomizer which enables compactification of the whole apparatus while securing cooling capacity of thermoelectric elements, and can secure reliability of bonding the thermoelectric elements. <P>SOLUTION: The electrostatic atomizer includes a discharge electrode 1 and a heat exchange means for cooling the discharge electrode 1 to generate dew condensation water on the surface of the discharge electrode 1, and applies a high voltage to the dew condensation water retained by the discharge electrode 1 to generate charged particulate water. The heat exchange means is provided with a pair of thermoelectric elements 2 and heat-releasing energizing substrates 3 each mechanically and electrically connected to the heat releasing side of the thermoelectric element 2. An inflow recess for making solder flow thereinto is formed in the mounting surface at the tip end of the heat-releasing energizing substrate 3. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electrostatic atomizer, and more particularly to a technique for condensing water for electrostatic atomization.

  As an electrostatic atomizer capable of generating charged fine particle water, one that generates charged fine particle water by applying a voltage to condensed water generated by cooling is known (see Patent Document 1). This electrostatic atomizer is as shown in FIG. 13, and a heat exchange block 60 is configured by sandwiching a plurality of pairs of thermoelectric elements 2 with circuit boards 50 from both sides. The circuit board 50 is formed by forming a circuit pattern 52 on one surface of an insulating substrate 51, and the circuit pattern 52 of one circuit board 50 electrically connects the end portions on the heat radiation side (lower side in the figure) of the thermoelectric element 2. The end portions on the heat absorption side (upper side in the figure) of the thermoelectric element 2 are electrically connected by the circuit pattern 52 of the other circuit board 50.

  A high heat conductive cooling plate 70 is connected to the circuit board 50 on the heat absorption side of the heat exchange block 60, and the discharge electrode 1 is erected on the cooling plate 70. Further, a dedicated heat radiation member 71 is mechanically connected to the circuit board 50 on the heat radiation side of the heat exchange block 60.

  In the electrostatic atomizer having the above configuration, when the thermoelectric element 2 is energized by an external power source, the heat absorption side of the thermoelectric element 2 cools the discharge electrode 1 through the circuit pattern 52, the insulating substrate 51, and the cooling plate 70, and discharges. Condensed water is generated on the surface of the electrode 1. A high-voltage lead wire 80 is connected to the discharge electrode 1, and a high voltage is applied to the condensed water on the surface of the discharge electrode 1 through the high-voltage lead wire 80, thereby generating charged fine particle water by an electrostatic atomization phenomenon. Let

  However, the conventional electrostatic atomizer described above has a problem that the entire apparatus is enlarged. This is because a large heat exchange block 60 in which a large number of thermoelectric elements 2 are sandwiched between a pair of circuit boards 50 as described above is required as heat exchange means, and heat radiation from the heat exchange block 60 is required. This is because it is necessary to dispose a dedicated heat radiating member 71 in order to efficiently perform the above.

JP 2006000826 A

  The present invention was invented in view of the above-mentioned problems, and the electrostatic atomization capable of downsizing the entire apparatus while ensuring the cooling capacity by the thermoelectric element and further ensuring the reliability of joining of the thermoelectric elements. It is an object to provide an apparatus.

  The present invention that solves the above-described problems includes a discharge electrode 1 and heat exchange means that cools the discharge electrode 1 to generate condensed water on the surface thereof, and applies a high voltage to the condensed water held by the discharge electrode 1. An electrostatic atomizer that generates charged fine particle water. The heat exchanging means includes a thermoelectric element 2 that forms a pair, and a heat dissipation energizing substrate 3 that is mechanically and electrically connected to the heat dissipation side of the thermoelectric element 2. The heat dissipation current-carrying substrate 3 has a land portion 30 on which the thermoelectric element 2 is mounted by solder bonding, and an inflow recess 35 through which the solder 4 flows is formed on the mounting surface 32 of the land portion 30. ing.

  According to the electrostatic atomizer of the present invention, the heat dissipation current supply substrate 3 connected to the thermoelectric element 2 is configured to perform both heat dissipation and current supply of the thermoelectric element 2, so that heat exchange for cooling the discharge electrode 1 is performed. The means, and thus the entire device, is greatly reduced in size. Then, a part of the solder 4 flows into the inflow recess 35 provided on the mounting surface 32, whereby the entire solder 4 is held on the mounting surface 32 in a well-balanced manner. Thereby, the self-alignment property of the thermoelectric element 2 by the solder 4 is improved, and as a result, the reliability of joining of the thermoelectric element 2 is ensured.

  Further, in the electrostatic atomizer of the present invention, the inflow recess 35 is preferably a minute recess for improving the wetting and spreading property of the solder 4. By doing in this way, the self-alignment property by the solder 4 is further ensured. In addition, the generation of voids in the layer of solder 4 is also suppressed, and a decrease in cooling performance due to voids is prevented.

  At this time, the inflow recess 35 is preferably a combination of a plurality of grooves 36, and the plurality of grooves 36 are formed radially from the center of the mounting surface 32 of the land portion 30. It is preferable that By doing in this way, the wet spreading property of the solder 4 can further be improved.

  Further, the heat-dissipating energizing substrate 3 is obtained by integrally connecting the substrate body 31 and the land portion 30 with a land support portion 34, and the inflow recess 35 extends from the land portion 30 to the land support portion 34. It is preferable that By doing in this way, the surplus part of the solder 4 when the thermoelectric element 2 is soldered can be released to the land support portion 34 side, and as a result, the placement accuracy of the thermoelectric element 2 to be soldered is improved. Can do.

  Moreover, in the electrostatic atomizer of the present invention, the inflow recess 35 may be a solder pool recess 39 formed in the center of the mounting surface 32 of the land portion 30. By doing so, the solder 4 melted on the mounting surface 32 is accumulated around the concave hole 39, and the surface tension of the solder 4 is centered on the joint surface of the thermoelectric element 2 and the center of the mounting surface 32. Acts to pull in. Thereby, the self-alignment property is improved, and as a result, the positional accuracy of the thermoelectric element 2 is improved.

  Moreover, in the electrostatic atomizer of this invention, it is preferable to form the solder escape part 40 indented rather than the mounting surface 32 in the periphery of the said land part 30. FIG. By doing in this way, the surplus part of the solder 4 when the thermoelectric element 2 is soldered can be smoothly released to the peripheral portion, and as a result, the placement accuracy of the thermoelectric element 2 to be soldered is improved. Can do.

  And in the electrostatic atomizer of this invention, the heat absorption side of the thermoelectric element 2 which makes a pair is electrically connected through the circuit pattern formed in the surface of the discharge electrode 1 or the discharge electrode 1, and a thermoelectric element 2 and the discharge electrode 1 are preferably integrated. In this way, the discharge electrode 1 can be cooled with high efficiency without arranging a large number of thermoelectric elements 2, and further downsizing and energy saving of the entire apparatus can be realized.

  According to the electrostatic atomizer of the present invention, the heat exchange means includes a thermoelectric element that forms a pair, and a heat dissipation current-carrying substrate that is mechanically and electrically connected to the heat dissipation side of the thermoelectric element. Since the inflow recess is provided on the mounting surface of the land part of the current carrying substrate, the entire device is made compact while ensuring the cooling capacity to generate dew condensation water on the discharge electrode, and the reliability for joining thermoelectric elements The effect that can also be secured.

It is a principal part perspective view of the electrostatic atomizer of an example in embodiment of this invention. It is a schematic sectional drawing of an electrostatic atomizer same as the above. The principal part of the electricity supply board for heat dissipation with which the electrostatic atomizer same as the above is shown is shown, (a) is a plan view and (b) is a side view. (A), (b) is a side view which shows the modification of the inflow recess provided in the electricity supply board for heat dissipation. (A), (b) is a top view which shows another modification of an inflow recess. (A), (b) is a top view which shows another modification of an inflow recess. It is a top view which shows another modification of an inflow recess. (A), (b), (c) is a top view which shows another modification of an inflow recess. The other modification of an inflow recess is shown, (a) is a top view, (b) is the sectional view on the AA line of (a). (A), (b), (c) is a top view which shows another modification of an inflow recess. The modification which provided the solder escape part in the land part is shown, (a) is a top view, (b) is a side view. It is a side view which shows a mode that the thermoelectric element was mounted in the land part of FIG. It is sectional drawing which shows the conventional electrostatic atomizer.

  The present invention will be described based on embodiments shown in the accompanying drawings.

  1 and 2 schematically show an example of an electrostatic atomizer in an embodiment of the present invention. The electrostatic atomizer of this example includes a pair of thermoelectric elements 2 of P type and N type, and discharge electrodes 1 are joined to the heat absorption side of both thermoelectric elements 2. As the thermoelectric element 2, a BiTe Peltier element is used. The arrangement of the thermoelectric elements 2 is not limited to a pair, and may be an arrangement including a plurality of pairs of P-type and N-type.

  The discharge electrode 1 has a shape in which a columnar discharge portion 1b protrudes from a central portion of a flat base portion 1a, and is made of a conductive metal such as brass, aluminum, copper, tungsten, or titanium. The material of the discharge electrode 1 is not limited to metal, and other materials such as conductive resin and carbon may be used as long as the material has high electrical conductivity.

  The heat absorption side of each thermoelectric element 2 is directly joined to the bottom surface of the base portion 1a of the discharge electrode 1 made of a conductive material with solder or a conductive adhesive so that the discharge electrode 1 and each thermoelectric element 2 are integrated. It has become. That is, the heat absorption sides of the thermoelectric element 2 forming a pair are electrically connected via the discharge electrode 1 to be cooled, and the discharge electrode 1 is energized from the N-type thermoelectric element 2 to the P-type thermoelectric element 2. Is a structure that is cooled.

  On each heat dissipation side of the pair of thermoelectric elements 2, a heat dissipation current-carrying substrate 3 made of a conductive and heat conductive material (for example, aluminum, copper, etc.) is integrally connected via a solder 4. The heat dissipation energizing substrate 3 is a thin plate-like member arranged so that the energizing direction (vertical direction in the drawing) of the thermoelectric element 2 is the thickness direction.

  The pair of heat-dissipating current-carrying boards 3 penetrates the side peripheral wall 10a of the casing 10 having a cylindrical shape, and the end portion on the side where the thermoelectric element 2 is mounted projects into the storage space S surrounded by the side peripheral wall 10a. It is held in the state. The housing 10 is made of an insulating material. The ends of the heat-dissipating energizing substrates 3 that protrude outward from the housing 10 are electrically connected via a DC power source 20 to form an electric circuit 6 for heat exchange.

  That is, the cylindrical housing 10 accommodates the discharge electrode 1, the thermoelectric element 2, and the end portion of the heat dissipation current-carrying substrate 3 in the storage space S. The bottom wall portion of the housing 10 includes A heat input opening 10b that exposes the heat input surface 33 of each heat dissipation energizing substrate 3 to the outside is provided. The heat input surface 33 is a portion where a beam for soldering is incident and the like will be described in detail later.

  Furthermore, in the electrostatic atomizer of this example, the counter electrode 11 is disposed at a position (upward position in the figure) facing the discharge portion 1b of the discharge electrode 1. The counter electrode 11 has a ring shape with a discharge hole 12 formed through the center. A voltage application unit 7 for applying a high voltage is electrically connected to the counter electrode 11. In this example, the counter electrode 11 is supported by the housing 10, but may be supported by a structure different from the housing 10.

  In the electrostatic atomizer of the present example configured as described above, charged fine particle water is generated as follows.

  That is, when a voltage is applied by the DC power source 20 so that a current flows from the N-type thermoelectric element 2 to the P-type thermoelectric element 2 through the discharge electrode 1, the discharge electrode 1 is directly cooled by the heat absorption of each thermoelectric element 2. As a result, condensed water is generated on the surface of the discharge electrode 1. Here, when a positive high voltage is applied to the counter electrode 11 by the voltage application unit 7 connected to the counter electrode 11 side, an electric field is formed between the discharge electrode 1 and the counter electrode 11. Due to this electric field, a negative high voltage is applied to the dew condensation water held by the discharge part 1b, and charged fine particle water is generated based on the dew condensation water.

  At this time, the heat radiation from each thermoelectric element 2 is efficiently performed through the heat radiation current-carrying substrate 3 solder-bonded to the heat radiation side of each thermoelectric element 2. Therefore, in the electrostatic atomizer of this example, a compact structure in which a pair of thermoelectric elements 2 and a pair of heat-dissipating current-carrying substrates 3 are mechanically and electrically joined without separately mounting a special heat-dissipating member. Efficient heat dissipation (and thus efficient cooling of the discharge electrode 1) is possible. Further, heat dissipation through the heat dissipation current-carrying substrate 3 is also performed through the housing 10, and more efficient heat dissipation is possible.

  Even when the counter electrode 11 is not provided, it is possible to generate an electrostatic atomization phenomenon in the condensed water of the discharge electrode 1 to generate charged fine particle water. Specifically, a high voltage application unit (not shown) for applying a negative high voltage to the entire circuit in the electric circuit 6 that connects the discharge electrode 1, the thermoelectric element 2, the heat dissipation energizing substrate 3, and the DC power supply 20. Connect. According to this, after applying a negative high voltage to the entire electric circuit 6 by the high voltage application unit, an offset voltage is applied between the thermoelectric elements 2 by the DC power source 20 in the electric circuit 6 to flow a current. Can do. When the discharge electrode 1 is cooled by energization between the two thermoelectric elements 2, dew condensation water is generated on the surface thereof, and the negative high voltage applied to the discharge electrode 1 by the high voltage application unit is statically applied to the dew condensation water on the surface of the discharge electrode 1. Causes electroatomization.

  Further, the thermoelectric elements 2 forming a pair are not electrically connected to each other by the discharge electrode 1 itself, and although not shown, a circuit pattern is formed on the surface of the base portion 1a of the discharge electrode 1 made of an insulating material, for example. It may be configured to be electrically connected via the circuit pattern. Even in this case, the discharge electrode 1 and the thermoelectric element 2 can be integrated in a compact manner.

  Hereinafter, the configuration of the heat dissipation current-carrying substrate 3 included in the electrostatic atomizer of this example will be described in more detail.

  A heat-dissipating current-carrying board 3 that conducts electricity to the thermoelectric element 2 and dissipates heat from the thermoelectric element 2 as a single member is used for mounting the thermoelectric element 2 on the end in the longitudinal direction of a long rectangular substrate body 31. The land portion 30 is formed. The land portion 30 has a square shape in plan view, and is integrally connected to the substrate body 31 by a land support portion 34 that is narrower than the land portion 30. As shown in FIG. 3, the land support portion 34 extends from the central portion of one side 30 a that forms the outer shape of the land portion 30.

  One side of the land portion 30 is a mounting surface 32 for soldering the heat radiation side end of the thermoelectric element 2, and the other side is a heat input surface 33. That is, the mounting surface 32 and the heat input surface 33 are at the front and back positions of the land portion 30 that is plate-shaped, and are both formed in a rectangular shape. An inflow recess 35 is formed in the mounting surface 32 of the land portion 30. The inflow recess 35 improves self-alignment by the solder 4 on the mounting surface 32. Note that, in the plan view showing the mounting surface 32, the portion that becomes the inflow recess 35 is hatched.

  In the heat dissipation current-carrying substrate 3, when the thermoelectric element 2 is solder-bonded on the mounting surface 32 of the land portion 30, the heat input surface 33 has a high height through the heat input opening 10 b (see FIG. 2 and the like) of the housing 10. The mounting surface 32 is heated by making an energy beam incident or the like to melt the solder 4.

  The solder 4 melted on the mounting surface 32 applies a surface tension to the thermoelectric element 2 so as to hold it in a predetermined posture on the mounting surface 32. That is, the self-alignment property by the solder 4 is exhibited on the mounting surface 32. At this time, a part of the solder 4 flows into the inflow recess 35 so that the entire solder 4 is held on the mounting surface 32 in a well-balanced manner. Thereby, as a result, the self-alignment of the thermoelectric element 2 by the solder 4 is favorably performed.

  In particular, in this example, the inflow recess 35 is formed by arranging a plurality of concave grooves 36 having a minute width in parallel, and the entire mounting surface 32 of the solder 4 is formed by a capillary phenomenon in each concave groove 36. Wetting and spreading is ensured.

  Further, by ensuring the wet spreading property of the solder 4, it is possible to suppress the generation of voids in the layer of the solder 4. If voids are formed in the layer of the solder 4, there is a problem that the self-alignment property is lowered as a result and a cooling performance is lowered by the thermoelectric element 2, but in this example, void generation is caused as described above. These problems are solved because they are suppressed. Each groove 36 preferably has a width of about 50 μm to 100 μm and a depth of about 10 μm to 100 μm.

  By the way, the inflow recess 35 on the mounting surface 32 may have a shape other than the above. Below, the various modifications of the inflow recess 35 are demonstrated based on figures.

  In the modification shown in FIG. 4, the cross-sectional shape of each groove 36 is different from that shown in FIG. That is, the groove 36 shown in FIG. 3 is recessed so as to have a rectangular cross section, but the groove 36 shown in FIG. 4A is recessed so as to have a semicircular cross section. A concave groove 36 shown in FIG. 5B is provided so as to have a triangular cross section. In addition, various cross-sectional shapes of the concave groove 36 can be selected. Further, the direction in which the concave grooves 36 are arranged in parallel on the mounting surface 32 can be appropriately selected.

  In the modification shown in FIG. 5, the grooves 36 are not simply arranged in parallel, but are provided so that the grooves 36 extending in different directions intersect each other. In the example of FIG. 5A, a plurality of concave grooves 36 arranged in parallel and a plurality of other concave grooves 36 arranged in parallel so as to extend in a direction different from the concave grooves 36 by 90 degrees are formed in a lattice shape. Crossed. In the example of FIG. 5B, the plurality of concave grooves 36 are formed radially from the center of the mounting surface 32 of the land portion 30. According to these modified examples, the wet spreading property of the solder 4 is further improved, so that the self-alignment property by the solder 4 is further improved.

  In the modification shown in FIG. 6, in addition to the modification of FIG. 5A, a part (two in the illustrated example) of the many recessed grooves 36 forming the inflow recess 35 is transferred from the land portion 30 to the land support portion. 34 is extended in a straight line. As shown in FIG. 6B, the surplus portion of the solder 4 when the thermoelectric element 2 is soldered to the extension portion 37 from the concave groove 36 is transferred to the extension portion 37 by capillarity in the concave groove 36. Escaped. As a result, the accuracy of the arrangement (element height, etc.) of the thermoelectric element 2 to be soldered is improved.

  In forming the extended portion 37 as in the above example, it may be formed in a shape extending linearly from a part of the grid-like concave groove 36 as shown in FIG. In the case of the example of FIG. 6, the respective concave grooves 36 intersecting in a lattice shape are extended in parallel or at right angles to the four sides of the land portion 30 that is rectangular, but in the case of the example of FIG. The land portion 30 extends obliquely with respect to the four sides.

  The modification shown in FIG. 8 is an example in which a minute inflow recess 35 is formed in a form other than the groove 36. Specifically, the inflow recesses 35 on the mounting surface 32 are formed by dispersing and arranging the fine holes 38 having a circular shape in plan view. The shape of the fine hole 38 is not particularly limited, but the depth is preferably about 10 μm to 100 μm, and the opening diameter on the mounting surface 32 is preferably about 50 μm to 150 μm.

  In the example of FIG. 8A, the fine holes 38 are arranged relatively randomly, but in the examples of FIG. 8B and FIG. 8C, the fine holes 38 are regularly spaced in two directions orthogonal to each other. Is arranged. As in the example of FIG. 8C, among the plurality of fine holes 38, the fine holes 38 on the end side may have a shape covering the edge of the mounting surface 32.

  In the modification shown in FIG. 9, the inflow recess 35 that improves the self-alignment property on the mounting surface 32 is not the minute groove 36 or the minute hole 38 that causes capillary action, but the center of the mounting surface 32. A recess hole 39 for solder pool is provided.

  The concave hole 39 has a depth of about 50 μm to 150 μm and an opening diameter of about 0.2 mm to 0.6 mm, and the solder 4 melted on the mounting surface 32 accumulates around the concave hole 39. The surface tension of the solder 4 acts to draw the center of the joint surface of the thermoelectric element 2 into the center of the mounting surface 32. That is, the self-alignment property is improved by providing the concave hole 39 at the center of the mounting surface 32, and as a result, the positional accuracy of the thermoelectric element 2 is improved. The opening shape of the recessed hole 39 is not limited to the illustrated circular shape, and may be other shapes such as a rectangular shape.

  The modification shown in FIG. 10 forms the inflow recess 35 on the mounting surface 32 by combining the concave hole 39 provided in the modification of FIG. 9 and the fine concave groove 36 provided in the other modification. It is a thing. In the example of FIG. 10A, minute grooves 36 are radially extended from the concave holes 39 that are opened in a circular shape. Moreover, in the example of FIG.10 (b) and FIG.10 (c), the concave hole 39 opened in square shape and the many concave grooves 36 which cross | intersect a grid | lattice form are combined.

  In the modified example shown in FIG. 11, in addition to providing the entire mounting surface 32 with the concave groove 36 of FIG. 5A, the solder relief that is recessed from the mounting surface 32 on the periphery of the land portion 30 on the mounting surface 32 side is provided. Part 40 is formed. The solder escape portion 40 has a shape in which the peripheral edge of the land portion 30 is chamfered in a tapered shape, but may have another shape as long as the solder 4 is allowed to escape.

  According to this example, as shown in FIG. 12, the surplus portion of the solder 4 when the thermoelectric element 2 is soldered is released to the solder escape portion 40 at the periphery of the land portion 30, and as a result, soldered. The accuracy of the arrangement (element height, etc.) of the thermoelectric element 2 is improved. Here, the concave groove 36 and the solder escape portion 40 are communicated with each other, but a structure that does not communicate may be used. Moreover, the structure which provided only the solder escape part 40, without providing the ditch | groove 36 grade | etc., May be sufficient.

  The present invention has been described above based on the embodiments shown in the accompanying drawings. However, the present invention is not limited to the embodiments of the above-described examples, and may be appropriately used in each example as long as it is within the intended scope of the present invention. It is possible to change the design of the above and to apply a combination of the configurations of the examples as appropriate.

DESCRIPTION OF SYMBOLS 1 Discharge electrode 2 Thermoelectric element 3 Heat-dissipating current supply board 4 Solder 30 Land part 31 Board | substrate body 32 Mounting surface 33 Heat input surface 34 Land support part 35 Inflow recess 36 Concave groove 39 Concave hole 40 Solder relief part

Claims (8)

  An electrostatic atomizer that includes a discharge electrode and a heat exchange means that cools the discharge electrode to generate condensed water on the surface thereof, and generates charged particulate water by applying a high voltage to the condensed water held by the discharge electrode The heat exchanging means includes a thermoelectric element that forms a pair and a heat-dissipating current-carrying board that is mechanically and electrically connected to the heat-dissipating side of the thermoelectric element. An electrostatic atomizer characterized in that an element has a land portion mounted by solder bonding, and an inflow recess for allowing solder to flow is formed on a mounting surface of the land portion.   The electrostatic atomizer according to claim 1, wherein the inflow recess is a minute recess for improving the wettability of solder.   The electrostatic atomizer according to claim 2, wherein the inflow recess is a combination of a plurality of concave grooves.   The electrostatic atomizer according to claim 3, wherein the plurality of concave grooves are formed radially from the center of the mounting surface of the land portion.   The heat-dissipating current-carrying board is obtained by integrally connecting a board main body and a land part with a land support part, and the inflow recess extends from the land part to the land support part. The electrostatic atomizer as described in any one of claim | item 2 -4.   The electrostatic atomizer according to claim 1, wherein the inflow recess is a solder pool recess formed in the center of the mounting surface of the land portion.   The electrostatic atomizer according to any one of claims 1 to 6, wherein a solder relief portion that is recessed from the mounting surface is formed at a peripheral edge of the land portion. 2. The thermoelectric element and the discharge electrode are integrated by electrically connecting the heat absorption sides of the thermoelectric elements forming a pair via a discharge electrode or a circuit pattern formed on the surface of the discharge electrode. The electrostatic atomizer as described in any one of -7.

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