JP2016146334A - Heating plate, conductive pattern sheet and vehicle with heating plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve invisibility of a conductive pattern of a defroster device.SOLUTION: A heating plate 10 comprises: a pair of glass plates 11, 12; a conductive pattern 40 arranged between the pair of glass plates 11, 12 and including a conductive thin wire 41; and junction layers 13, 14 arranged between the conductive pattern 40 and at least one of the pair of glass plates 11, 12. The conductive thin wire 41 of the conductive pattern 40 has a first surface 41a facing one of the pair of glass plates 11, 12, and a second surface 41b facing the other of the pair of glass plates 11, 12, (a) 0<|Wa-Wb|≤10 and (b) Sa≥10 holding for a width Wa (μm) of the first surface 41a of the conductive thin wire 41, a width Wb (μm) of the second surface 41b of the conductive thin wire 41, and a sectional area Sa (μm2) of the conductive thin wire 41.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle including a heat generating plate, a conductive pattern sheet, and a heat generating plate.

  2. Description of the Related Art Conventionally, as a defroster device used for a window glass such as a front window and a rear window of a vehicle, an apparatus in which a heating wire made of a tungsten wire is arranged on the entire window glass is known (for example, see Patent Document 1 and Patent Document 2) ). In this prior art, a heating wire arranged on the entire window glass is energized, and the window glass is heated by resistance heating to remove fogging of the window glass or to melt snow and ice adhering to the window glass. Or by evaporating the water droplets, it is possible to secure the sight of the occupant.

JP 2013-173402 A JP-A-8-72674

  As described above, the conventional defroster device uses a tungsten wire as the heating wire. In this case, in order to prevent the electric resistance of the heating wire from becoming too high due to the high electrical resistivity of tungsten, the sectional area of the heating wire is increased. Therefore, the heating wire using a tungsten wire is easily visually recognized by an observer. Visibility of the heating wire by an observer such as a driver deteriorates the visibility of the observer through the window glass.

  The present invention has been made in consideration of such points, and an object thereof is to improve the invisibility of the heating wire of the defroster device.

The heating plate according to the present invention is:
A pair of glass plates;
A conductive pattern disposed between the pair of glass plates and including a conductive fine wire; and
A bonding layer disposed between the conductive pattern and at least one of the pair of glass plates,
The conductive thin wire of the conductive pattern has a first surface facing one of the pair of glass plates, and a second surface facing the other of the pair of glass plates,
The width of the first surface of the conductive thin wire is W _a (μm), the width of the second surface of the conductive thin wire is W _b (μm), and the cross-sectional area of the conductive pattern is S _a (μm ² ). The following relations (a) and (b) are satisfied.
0 <| W _a −W _b | ≦ 10 (a)
S _a ≧ 10 (b)

  In the heat generating plate according to the present invention, the conductive pattern may be formed by patterning a conductive layer by etching.

  In the heat generating plate according to the present invention, the conductive pattern has a pattern defining a plurality of opening regions, and the conductive pattern extends between two branch points to define a plurality of opening regions. A connection element may be included.

  In the heat generating plate according to the present invention, in the conductive pattern, an average number of the connection elements extending from one branch point may be greater than 3.0 and less than 4.0.

  In the heat generating plate according to the present invention, the conductive pattern includes open regions surrounded by four, five, six, and seven connecting elements, respectively, and the open region included in the conductive pattern. Of these, the opening area surrounded by the six connection elements may be the largest.

  In the heat generating plate according to the present invention, at least a part of the plurality of connecting elements may have a curved or broken line shape when viewed from the normal direction of the plate surface of the heat generating plate.

The conductive pattern sheet according to the present invention is:
A substrate;
A conductive pattern provided on the base material and including a conductive fine wire; and
The conductive thin wire of the conductive pattern has a base end surface forming a surface on the substrate side, and a front end surface facing the base end surface,
The width of the front end surface of the conductive thin wire is W _c (μm), the width of the base end surface of the conductive thin wire is W _d (μm), and the cross-sectional area of the conductive pattern is S _b (μm ² ). Sometimes, a conductive pattern sheet that satisfies the following relationships (c) and (d).
0 <| W _c −W _d | ≦ 10 (c)
S _b ≧ 10 (d)

  A vehicle according to the present invention includes the above-described heat generating plate.

  According to the present invention, the invisibility of the conductive pattern of the defroster device can be improved.

FIG. 1 is a diagram for explaining an embodiment according to the present invention, and is a perspective view schematically showing a vehicle provided with a heat generating plate. In particular, FIG. 1 schematically shows an automobile provided with a heat generating plate as an example of a vehicle. FIG. 2 is a view of the heat generating plate as viewed from the normal direction of the plate surface. 3 is a cross-sectional view of the heat generating plate of FIG. FIG. 4 is a plan view showing an example of the pattern shape of the conductive pattern of the heat generating plate. FIG. 5 is a plan view showing another example of the pattern shape of the conductive pattern of the heat generating plate. FIG. 6 is an enlarged view showing a part of the conductive pattern of FIG. FIG. 7 is a cross-sectional view showing the cross-sectional shape of the conductive thin wire of the conductive pattern. FIG. 8 is a diagram for explaining an example of a method for manufacturing a heat generating plate. FIG. 9 is a diagram for explaining an example of a method of manufacturing a heat generating plate. FIG. 10 is a diagram for explaining an example of a method for manufacturing a heat generating plate. FIG. 11 is a diagram for explaining an example of a method of manufacturing a heat generating plate. FIG. 12 is a diagram for explaining an example of a method of manufacturing a heat generating plate. FIG. 13 is a diagram for explaining an example of a method for manufacturing a heat generating plate. FIG. 14 is a diagram for explaining a modification of the method for manufacturing the heat generating plate. FIG. 15 is a diagram for explaining a modification of the method for manufacturing the heat generating plate. FIG. 16 is a diagram for explaining a modification of the method for manufacturing the heat generating plate. FIG. 17 is a diagram for explaining a modification of the method for manufacturing the heat generating plate. FIG. 18 is a diagram for explaining a modification of the method for manufacturing the heat generating plate. FIG. 19 is a diagram for explaining another modification of the method for manufacturing the heat generating plate. FIG. 20 is a diagram for explaining another modification of the method for manufacturing the heat generating plate.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

  In the present specification, the terms “plate”, “sheet”, and “film” are not distinguished from each other only based on the difference in names. For example, the “conductive pattern sheet” is a concept including a member that can be called a plate or a film. Therefore, the “conductive pattern sheet” is a “conductive pattern plate (substrate)” or “conductive pattern”. It cannot be distinguished from a member called “film” only by the difference in designation.

  In addition, “sheet surface (plate surface, film surface)” means a target sheet-like member (plate-like) when the target sheet-like (plate-like, film-like) member is viewed as a whole and globally. It refers to the surface that coincides with the plane direction of the member or film-like member.

  In this specification, “joining” includes not only “main joining” that completely completes joining but also so-called “temporary joining” for temporarily fixing before “main joining”.

  In addition, as used in the present specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “orthogonal”, “identical”, and values of length and angle are strict. Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

  FIGS. 1-20 is a figure for demonstrating one Embodiment by this invention. Of these, FIG. 1 is a diagram schematically showing an automobile equipped with a heat generating plate, FIG. 2 is a view of the heat generating plate viewed from the normal direction of the plate surface, and FIG. 3 is a heat generating of FIG. It is a cross-sectional view of a board. In addition, the heat generating plate in the present embodiment may be called laminated glass.

  As shown in FIG. 1, an automobile 1 as an example of a vehicle has window glasses such as a front window, a rear window, and a side window. Here, an example in which the front window 5 is composed of a heat generating plate 10 is illustrated. The automobile 1 has a power source 7 such as a battery.

  FIG. 2 shows the heat generating plate 10 viewed from the normal direction of the plate surface. Moreover, the cross-sectional view corresponding to the III-III line of the heat generating plate 10 of FIG. 2 is shown in FIG. In the example shown in FIG. 3, the heating plate 10 includes a pair of glass plates 11 and 12, a conductive pattern sheet (pattern sheet) 20 disposed between the pair of glass plates 11 and 12, and the glass plate 11. , 12 and the conductive pattern sheet 20 are joined. In the example shown in FIGS. 1 and 2, the heat generating plate 10 is curved. However, in FIGS. 3 and 13 to 20, the heat generating plate 10 and the heat generating plate 10 are shown for simplification and easy understanding. The glass plates 11 and 12 are illustrated in a flat plate shape.

  The conductive pattern sheet 20 energizes the sheet-like base material 30, the holding layer 31 laminated on the base material 30, the conductive pattern 40 formed on the holding layer 31, and the conductive pattern 40. Wiring portion 15, and connection portion 16 that connects conductive pattern 40 and wiring portion 15.

  In the example shown in FIGS. 2 and 3, the conductive pattern 40 is energized from the power source 7 such as a battery via the wiring portion 15 and the connection portion 16, and the conductive pattern 40 is heated by resistance heating. The heat generated in the conductive pattern 40 is transmitted to the glass plates 11 and 12 through the bonding layers 13 and 14, and the glass plates 11 and 12 are warmed. Thereby, the cloudiness by the dew condensation adhering to the glass plates 11 and 12 can be removed. Moreover, when snow and ice adhere to the glass plates 11 and 12, this snow and ice can be melted. Therefore, a passenger | crew's visual field is ensured favorable.

  In particular, when the glass plates 11 and 12 are used for a front window of an automobile, it is preferable to use a glass plate having a high visible light transmittance so as not to obstruct the view of the passenger. Examples of the material of the glass plates 11 and 12 include soda lime glass and blue plate glass. The glass plates 11 and 12 preferably have a transmittance in the visible light region of 90% or more. Here, the visible light transmittance of the glass plates 11 and 12 is measured within a measurement wavelength range of 380 nm to 780 nm using a spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation, JIS K 0115 compliant product). Is specified as an average value of transmittance at each wavelength. The visible light transmittance may be lowered by coloring a part or the whole of the glass plates 11 and 12. In this case, it is possible to block direct sunlight and to make it difficult to visually recognize the inside of the vehicle from outside the vehicle.

  Moreover, it is preferable that the glass plates 11 and 12 have a thickness of 1 mm or more and 5 mm or less. With such a thickness, the glass plates 11 and 12 excellent in strength and optical characteristics can be obtained.

  The glass plates 11 and 12 and the conductive pattern sheet 20 are bonded via bonding layers 13 and 14, respectively. As the bonding layers 13 and 14, layers made of materials having various adhesiveness or tackiness can be used. The bonding layers 13 and 14 preferably have a high visible light transmittance. As a typical joining layer, the layer which consists of polyvinyl butyral (PVB) can be illustrated. The thickness of the bonding layers 13 and 14 is preferably 0.15 mm or more and 0.7 mm or less, respectively.

  The heating plate 10 is not limited to the illustrated example, and may be provided with other functional layers expected to exhibit a specific function. In addition, one functional layer may exhibit two or more functions. For example, glass plates 11 and 12 of the heat generating plate 10, bonding layers 13 and 14, and a base material of the conductive pattern sheet 20 described later. A function may be given to at least one of 30. Examples of functions that can be imparted to the heating plate 10 include an antireflection (AR) function, a hard coat (HC) function having scratch resistance, an infrared shielding (reflection) function, an ultraviolet shielding (reflection) function, and a polarization function. An antifouling function and the like can be exemplified.

  Next, the conductive pattern sheet 20 will be described. The conductive pattern sheet 20 energizes the sheet-like base material 30, the holding layer 31 laminated on the base material 30, the conductive pattern 40 formed on the holding layer 31, and the conductive pattern 40. Wiring portion 15, and connection portion 16 that connects conductive pattern 40 and wiring portion 15. The conductive pattern sheet 20 has substantially the same planar dimensions as the glass plates 11 and 12 and may be disposed over the entire heat generating plate 10, or on a part of the heat generating plate 10 such as the front portion of the driver's seat. May be arranged only.

  The sheet-like base material 30 functions as a base material that supports the holding layer 31 and the conductive pattern 40. The base material 30 is an electrically insulating substrate that is transparent in general terms that transmits a wavelength in the visible light wavelength band (380 nm to 780 nm). In the example shown in FIGS. 2, 4, and 5, the base material 30 has substantially the same dimensions as the glass plates 11 and 12 and has a substantially trapezoidal planar shape.

  The resin contained in the base material 30 may be any resin as long as it transmits visible light and can appropriately support the holding layer 31 and the conductive pattern 40, but a thermoplastic resin can be preferably used. . Examples of the thermoplastic resin include acrylic resins such as polymethyl methacrylate, polyester resins such as polyvinyl chloride, polyethylene terephthalate, and amorphous polyethylene terephthalate (A-PET), polyolefin resins such as polyethylene resin and polypropylene, triacetyl cellulose ( Cellulose resins such as cellulose triacetate), polystyrene, polycarbonate resin, AS resin, and the like. In particular, acrylic resin and polyvinyl chloride are preferable because they are excellent in etching resistance, weather resistance, and light resistance.

  Moreover, it is preferable that the base material 30 has a thickness of 0.03 mm or more and 0.3 mm or less in consideration of retainability of the conductive pattern 40, light transmittance, and the like.

  The holding layer 31 has a function of improving the bondability between the base material 30 and the conductive pattern 40 and holding the conductive pattern 40. The holding layer 31 can be formed by, for example, laminating a transparent electrically insulating resin sheet on the base material 30, or can be formed by applying a resin material on the base material 30. As such a holding layer 31, for example, polyvinyl butyral (PVB), a two-component curable urethane adhesive, a two-component curable epoxy adhesive, or the like can be used. Moreover, when the base material 30 is peeled after bonding the conductive pattern sheet 20 to the glass plate 11 via the bonding layer 13 (temporary bonding) as described later, the holding layer 31 includes a peeling layer. Also good. In addition, the thickness of the holding layer 31 can be set to 1 μm or more and 100 μm or less in consideration of light transmittance, bondability between the base material 30 and the conductive pattern 40, and the like. Preferably, the thickness of the holding layer 31 can be 1 μm or more and 15 μm or less.

  The conductive pattern 40 will be described with reference to FIGS. 4 and 5 are both plan views of the conductive pattern sheet 20 viewed from the normal direction of the sheet surface. FIG. 6 is an enlarged view showing a part of the conductive pattern 40 of FIG.

  The conductive pattern 40 is energized from the power source 7 such as a battery through the wiring portion 15 and the connection portion 16 and generates heat by resistance heating. And when this heat | fever is transmitted to the glass plates 11 and 12 through the joining layers 13 and 14, the glass plates 11 and 12 are warmed.

  FIG. 4 shows an example of the pattern shape of the conductive pattern 40. In the example shown in FIG. 4, a plurality of conductive thin wires 41 that connect the pair of connection portions 16 are provided. In the illustrated example, each of the plurality of conductive thin wires 41 extends from one connection portion 16 to the other connection portion 16 in a wavy line pattern. The plurality of conductive thin wires 41 are arranged away from each other in a direction non-parallel to the extending direction of the conductive thin wires 41. In particular, the plurality of conductive thin wires 41 are arranged in a direction orthogonal to the extending direction of the conductive thin wires 41. Each thin conductive wire 41 may extend between the pair of connecting portions 16 in a pattern such as a straight line, a broken line, or a sine wave in addition to the wavy line pattern. Note that adjacent conductive thin wires 41 in a direction non-parallel to the extending direction of the conductive thin wires 41 may be connected by a thin wire, that is, a connecting wire. In addition, when the pattern shape of the conductive pattern 40 is a pattern shape as shown in FIG. 4, sufficient invisibility (conductive thin wire 41 from a distance of 30 cm or more from the conductive thin wire 41 that is a normally assumed visual distance is provided. In order to obtain the above, the maximum width W of the conductive thin wires 41 is set to 2 to 7 μm, and the distance between adjacent conductive thin wires 41, that is, the pitch is 50 μm or more and 150 μm. The following is preferable.

  5 and 6 show other examples of the pattern shape of the conductive pattern 40. FIG. In the example shown in FIGS. 5 and 6, the conductive thin wires 41 of the conductive pattern 40 are arranged in a mesh pattern that defines a large number of opening regions 44. The conductive pattern 40 includes a plurality of connecting elements 45 extending between the two branch points 43 and defining an open area 44. That is, the conductive thin wires 41 of the conductive pattern 40 are configured as a collection of a large number of connection elements 45 that form branch points 43 at both ends.

  In the example shown in FIGS. 5 and 6, the large number of opening regions 44 of the conductive pattern 40 are arranged in a shape and a pitch that do not have repetitive regularity (periodic regularity). In particular, in the illustrated example, a large number of open regions 44 coincide with each Voronoi region in a Voronoi diagram generated from random two-dimensionally distributed generating points distributed within an upper limit value and a lower limit value between adjacent generating points. Are arranged as follows. In other words, each connection element 45 of the conductive pattern 40 coincides with each boundary of the Voronoi region in the Voronoi diagram. Each branch point 43 of the conductive pattern 40 coincides with the Voronoi point in the Voronoi diagram. This Voronoi diagram is obtained by a known method as disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-178556, Japanese Patent Application Laid-Open No. 2013-238029, and the like. Description is omitted.

  When the conductive pattern has a large number of opening regions arranged in a shape and pitch having a repeating regularity (periodic regularity) such as a square lattice arrangement or a honeycomb arrangement, the repeating rule of the arrangement of the many opening areas Due to the nature, light glare may be visually recognized. A light beam is a predetermined streaky pattern on the heating plate when light from the opposite side of the observer is incident on the heating plate, for example, when the light of an oncoming vehicle headlight enters the front window of an automobile. This phenomenon is observed when the light is dispersed in the above pattern, and in particular, when a large number of opening regions of the conductive pattern are arranged in a shape and pitch having regularity, the light spot tends to be noticeable. . And when this light beam is visually recognized by an observer such as a driver, the visibility of the observer through the heat generating plate is deteriorated. On the other hand, according to the conductive pattern 40 having a large number of open regions 44 arranged in a shape and a pitch that do not have repeating regularity (periodic regularity) as shown in FIGS. It is possible to effectively suppress the occurrence of light glare on the plate 10.

  In the 30 conductive patterns 40 shown in FIGS. 5 and 6, the average number of connecting elements 45 extending from one branch point 43 is greater than 3.0 and less than 4.0. Thus, when the average number of connecting elements 45 extending from one branch point 43 is greater than 3.0 and less than 4.0, a pattern in which regularity is lost from the honeycomb arrangement can be obtained. When the average number of connecting elements 45 extending from one branch point 43 is more than 3.0 and less than 4.0, the arrangement of the opening regions 44 is made irregular so that the opening regions 44 have a repeating regularity (periodicity). Therefore, it is possible to prevent the direction in which the lamps are arranged with stability from occurring stably, and as a result, it is possible to more effectively suppress the occurrence of light glare on the heating plate 10. At the same time, since the arrangement of the connection elements 45 is based on the honeycomb arrangement, the connection elements 45 are evenly dispersed, and as a result, it is possible to effectively suppress uneven heat generation.

  Strictly speaking, the average number of connection elements 45 extending from one branch point 43 is determined by examining the number of connection elements 45 extending for all branch points 43 included in the conductive pattern 40. However, in actuality, the connection extending from one branch point 43 is considered in consideration of the size of the opening area 44 per one defined by the conductive thin wire 41 and the like. In a section having an area expected to reflect the overall trend of the number of elements 45, for a number of branch points 43 deemed appropriate in view of the degree of variation in the number of objects to be investigated, The number of connection elements 45 extending from each branch point 43 is examined to calculate an average value, and the calculated value is the average value of the number of connection elements 45 extending from one branch point 43 for the conductive pattern 40. Treat as Unishi may be. For example, an average value calculated by counting the number of connection elements 45 extending from 100 branch points 43 included in the 300 mm × 300 mm region of the conductive pattern 40 using an optical microscope or an electron microscope is used as the conductive pattern. It can be treated as an average value of the number of connection elements 45 extending from one branch point 43 for the sex pattern 40.

  In the conductive pattern 40 shown in FIGS. 5 and 6, the conductive pattern 40 includes open regions 44 surrounded by four, five, six and seven connecting elements 45, respectively, Among the opening areas 44 included in the sex pattern 40, the opening area 44 surrounded by the six connection elements 45 is the largest. That is, the opening region 44 surrounded by the six connection elements 45 is included in the conductive pattern 40 more than the opening region 44 surrounded by the other number of connection elements 45. Yes.

  In such a conductive pattern 40, the arrangement of the opening regions 44 is an arrangement in which the regularity of the shape and arrangement of each opening region is broken from a honeycomb arrangement in which regular hexagons having the same shape are regularly arranged, in other words, In addition, it is possible to obtain an arrangement in which the shape and arrangement of each opening region are randomized with reference to the honeycomb arrangement. Thereby, it is possible to suppress the occurrence of clear roughness in the arrangement of the opening regions 44, and it is possible to distribute a large number of the opening regions 44 with a substantially uniform density, that is, with a substantially uniform distribution. As a result, heat generation unevenness can be effectively suppressed. In addition, it is possible to stably make the arrangement of the opening regions 44 completely irregular, that is, to prevent the direction in which the opening regions 44 are regularly arranged from existing. Therefore, it is possible to more effectively suppress the occurrence of light glare on the heat generating plate 10.

  Strictly speaking, the number of connection elements 45 surrounding one opening region 44 is determined by examining the number of connection elements 45 surrounding the opening region 44 for all opening regions 44 included in the conductive pattern 40. become. However, in practice, the overall trend of the number of connecting elements 45 surrounding one opening region 44 is considered in consideration of the size of each opening region 44 defined by the conductive thin wires 41. In one section having an area that is expected to reflect the number of opening regions 44 that are considered to be appropriate in consideration of the degree of variation in the number of objects to be investigated, connection elements 45 surrounding each opening region 44. The number of open regions 44 for each number of connection elements 45 surrounding the periphery may be integrated. For example, the number of connection elements 45 surrounding each of the 100 opening regions 44 included in the 300 mm × 300 mm region of the conductive pattern 40 is counted using an optical microscope or an electron microscope, and the connection elements 45 surrounding the periphery are counted. Using the value obtained by integrating the number of the opening regions 44 for each number, it is possible to determine the number of the opening regions 44 surrounded by the connection elements 45 in the conductive pattern 40 with the largest number. . In addition, when the pattern shape of the conductive pattern 40 is a mesh shape as shown in FIG. 5, sufficient invisibility (conductive thin wire 41 from a distance of 30 cm or more from the conductive thin wire 41 that is a normal viewing distance is assumed. In order to obtain the above, the distance between the centers of the adjacent opening regions 44, that is, the pitch is not less than 50 μm and not more than 150 μm. The following is preferable.

  Examples of the material for forming the conductive pattern 40 include metals such as gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, and tungsten, and nickel. -One or more alloys of two or more metals selected from these exemplified metals such as chromium alloy, brass, bronze and the like can be exemplified.

  Next, the cross-sectional shape of the conductive thin wire 41 of the conductive pattern 40 will be described with reference to FIG. FIG. 7 is an enlarged view of the cross section of the conductive pattern sheet 20 corresponding to the line AA in FIGS. 4 and 5.

  In the example shown in FIG. 7, the conductive pattern sheet 20 includes a sheet-like base material 30, a holding layer 31 laminated on the base material 30, and a conductive pattern 40 formed on the holding layer 31. have. The conductive thin wire 41 is a base that forms a surface on the base material 30 side in a cross section orthogonal to the extending direction (longitudinal direction) of the conductive thin wire 41 (cross section as shown in FIG. 7, hereinafter also referred to as a main cutting surface). It has an end surface 41b, a distal end surface 41a facing the proximal end surface 41b, and side surfaces 41c and 41d connecting the distal end surface 41a and the proximal end surface 41b. In the present embodiment, the distal end surface 41a of the conductive thin wire 41 finally forms a first surface facing one of the pair of glass plates 11 and 12 of the heating plate 10, and the proximal end surface of the conductive thin wire 41 41 b finally forms a second surface facing the other of the pair of glass plates 11, 12 of the heat generating plate 10.

In the heat generating plate in which the conductive pattern 40 shown in FIG. 7 is incorporated, that is, the heat generating plate 10 shown in FIG. 3, the heat generating plate 10 on the first surface 41 a of the conductive thin wire 41 on the main cut surface is formed. the along width W _{a (μm),} mainly width along a plate surface of the heating plate 10 of the second surface 41b of the electroconductive thin line 41 in a cross section in a W _{b (μm),} the electroconductive thin line 41 in the main cross When the cross-sectional area is S _a (μm ² ),
0 <| W _a −W _b | ≦ 10 (a)
S _a ≧ 10 (b)
To meet the relationship.

Further, in the conductive pattern sheet 20 shown in FIG. 7, the width along the sheet surface of the conductive pattern sheet 20 of the base end surface 41b of the conductive thin wire 41 in the main cut surface is set to W _d (μm), and the main cut surface. When the width along the sheet surface of the conductive pattern sheet 20 of the front end surface 41a of the conductive thin wire 41 is W _c (μm), and the cross-sectional area of the conductive thin wire 41 at the main cut surface is S _b (μm ² ). In addition,
0 <| W _c −W _d | ≦ 10 (c)
S _b ≧ 10 (d)
To meet the relationship.

  In the example shown in FIG. 7, the first surface (front end surface) 41a and the second surface (base end surface) 41b of the conductive thin wire 41 are parallel to each other. One side surface 41c of the conductive thin wire 41 forms a tapered surface that approaches the other side surface 41d as the distance from the substrate 30 increases along the normal direction of the sheet surface of the conductive pattern sheet 20. In addition, the other side surface 41 d of the conductive thin wire 41 has a tapered surface that approaches the one side surface 41 c as the distance from the substrate 30 increases along the normal direction of the sheet surface of the conductive pattern sheet 20. Therefore, the conductive thin wire 41 is formed so that its line width becomes narrower as it is separated from the base material 30 along the normal direction of the sheet surface of the conductive pattern sheet 20.

  As in the example shown in FIG. 3, in the state where the conductive pattern 40 is incorporated in the heat generating plate 10, one side surface 41 c of the conductive thin wire 41 is along the normal direction of the plate surface of the heat generating plate 10. As the distance from the glass plate 12 increases, the taper surface approaches the other side surface 41d. Further, the other side surface 41 d of the conductive thin wire 41 forms a tapered surface that approaches the one side surface 41 c as the distance from the glass plate 12 increases along the normal direction of the plate surface of the heat generating plate 10. Therefore, the conductive thin wire 41 is formed so that its line width becomes narrower as it is separated from the glass plate 12 along the normal direction of the plate surface of the heat generating plate 10.

That is, the conductive thin wire 41 has a substantially trapezoidal shape as a whole in a cross section orthogonal to the extending direction (longitudinal direction). More specifically, one side surface 41c of the conductive thin wire 41 is parallel to the sheet surface of the conductive pattern sheet 20 (the plate surface of the heat generating plate 10) on the first surface (tip surface) 41a and extends from the conductive thin wire 41. One end portion A along the width direction of the conductive thin wire 41 on the second surface (base end surface) 41b and one end A along the direction orthogonal to the current direction (hereinafter also referred to as the width direction of the conductive thin wire 41). and the end portion of the side B, the straight line L ₁ connecting the has a shape which is concave on the inner side (the other side surface 41d side). Similarly, the other side surface 41d of the conductive thin wire 41 has an end C on the other side along the width direction of the conductive thin wire 41 in the first surface (front end surface) 41a and a second surface (base end surface) 41b. and the end D of the other side along the width direction of the electroconductive thin line 41, the straight line L ₂ connecting the has a shape which is concave inward (one side face 41c side).

In the conductive pattern 40 having such a configuration, the widths W _a and W _c of the first surface (tip surface) 41a of the conductive thin wire 41 can be set to 2 μm or more and 13 μm or less. Further, the widths W _b and W _d of the second surface (base end surface) 41b of the conductive thin wire 41 can be set to 5 μm or more and 15 μm or less. Furthermore, the height H of the conductive thin wire 41, that is, the height H along the normal direction of the plate surface of the heat generating plate 10 (sheet surface of the conductive pattern sheet 20) can be set to 2 μm or more and 15 μm or less. . According to the conductive pattern 40 having the conductive thin wires 41 having such dimensions, since the conductive thin wires 41 are sufficiently thinned, the conductive patterns 40 can be effectively invisible.

3 and 7, the width W _b of the second surface 41b of the conductive thin wire 41 (the width W _d of the base end surface 41b of the conductive thin wire 41) is the maximum width of the conductive thin wire 41. Matches W.

  According to the conductive pattern 40 including the conductive thin wire 41 having a dimension and a cross-sectional area satisfying the relationship (a) and (b) or (c) and (d), the maximum width of the conductive thin wire 41 It is possible to secure a sufficient cross-sectional area to obtain appropriate conductivity while reducing W. Thereby, the appropriate electroconductivity of the electroconductive pattern 40 can be obtained, making the electroconductive pattern 40 invisible effectively.

On the other hand, when the value of (| W _a −W _b |) or (| W _c −W _d |) is larger than 10 μm, in order to ensure a sufficient cross-sectional area from the viewpoint of ensuring appropriate conductivity, It is necessary to increase the maximum width W of the thin conductive wire 41, thereby reducing the invisibility of the conductive pattern 40. Further, if the maximum width W of the conductive thin wire 41 is reduced, a sufficient cross-sectional area cannot be secured, and the electrical resistance of the conductive pattern 40 becomes too large, thereby reducing the conductivity of the conductive pattern 40. That is, it is not possible to achieve both adequate securing of appropriate conductivity and invisibility of the conductive pattern 40.

The widths W _a and W _c of the first surface (tip surface) 41 a of the conductive thin wire 41, the widths W _b and W _d of the second surface (base end surface) 41 b of the conductive thin wire 41, and the conductive thin wire 41. In actuality, the overall height of each dimension is reflected in consideration of the size of each open area 44 defined by the conductive thin wire 41, etc. Each dimension is measured for a number of conductive thin wires 41 (connection elements 45) considered to be appropriate in consideration of the degree of variation in the dimensions of the object to be investigated in one section having an area that can be expected. You may do it. For example, the dimensions measured using an optical microscope or an electron microscope at 100 locations of the conductive thin wires 41 (connecting elements 45) included in the 300 mm × 300 mm region of the conductive pattern 40 are the conductivity of the conductive pattern 40. It can handle as each dimension of the property thin line 41 (connection element 45).

  By the way, in the example shown in FIG. 3 and FIG. 7, the conductive thin wire 41 forming the conductive pattern 40 is located on the base material 30 side of the conductive thin wire 41 and the second surface (base end surface) of the conductive thin wire 41. ) Having a dark color layer 49 for forming 41b and a conductive metal layer 48 for forming the first surface (tip surface) 41a of the conductive thin wire 41 located on the opposite side of the conductive thin wire 41 from the substrate 30. doing. In other words, the dark color layer 49 covers the surface of the conductive metal layer 48 on the substrate 30 side.

  The dark color layer 49 is formed, for example, by applying a darkening process (blackening process) to a part of the material forming the conductive metal layer 48 and forming a metal oxide or metal sulfide on the part forming the conductive metal layer 48. It can provide by forming the film which becomes. The etching speed of the conductive metal layer 48 and the dark color layer 49 is different, and the conductive metal layer 48 is etched by the dark color layer 49 in the etching process of the conductive metal layer 48 and the dark color layer 49 using a photolithographic technique described later. The etching rate can be adjusted appropriately. Further, since the dark color layer 49 formed by the darkening process (blackening process) has a roughened surface, the effect of improving the adhesion between the conductive pattern 40 and the holding layer 31 can also be exhibited. .

  Next, an example of a method for manufacturing the heat generating plate 10 will be described with reference to FIGS. 8-13 is sectional drawing which shows an example of the manufacturing method of the heat generating plate 10 in order.

  First, a metal foil 51 is prepared, and a dark color film 52 is formed on one surface of the metal foil 51. The metal foil 51 forms the conductive metal layer 48 of the conductive thin wire 41. The dark color film 52 forms a dark color layer 49 of the conductive thin wire 41. Examples of the metal foil 51 include metals such as gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, and indium, and these exemplified metals such as nickel-chromium alloy and brass. An alloy foil of two or more selected metals can be used. The thickness of the metal foil 51 can be 2 μm or more and 15 μm or less. For example, the dark color film 52 is subjected to darkening treatment (blackening treatment) on a part of the material forming the metal foil 51 to form a film made of metal oxide or metal sulfide on the part forming the metal foil 51. Can be provided.

  Moreover, the base material 30 is prepared and the holding layer 31 is formed on one surface of the base material 30. As the base material 30, for example, a thermoplastic resin that transmits visible light can be used. Examples of the thermoplastic resin include acrylic resins such as polymethyl methacrylate, polyvinyl chloride, polyester resins such as polyethylene terephthalate (PET), amorphous polyethylene terephthalate (A-PET), polyethylene naphthalate (PEN), polyethylene, and polypropylene. , Polyolefin resins such as polymethylpentene and cyclic polyolefin, cellulose resins such as triacetylcellulose (cellulose triacetate), polystyrene, polycarbonate resin, AS resin and the like. In particular, acrylic resin and polyvinyl chloride are preferable because they are excellent in etching resistance, weather resistance, and light resistance. As the holding layer 31, for example, polyvinyl butyral (PVB), a two-component curable urethane adhesive, a two-component curable epoxy adhesive, or the like can be used. The holding layer 31 can be formed by, for example, laminating a sheet-like material on the base material 30, or can be formed by applying a fluid material on the base material 30.

  Next, as shown in FIG. 8, the metal foil 51 on which the dark color film 52 is formed and the base material 30 on which the holding layer 31 is formed are stacked so that the dark color film 52 and the holding layer 31 face each other. . At this time, since the surface of the dark color film 52 in contact with the holding layer 31 is roughened by a darkening process (blackening process), the resin material constituting the holding layer 31 has fine irregularities on the surface of the dark color film 52. Get in. Therefore, the dark color film 52 and the holding layer 31 are firmly joined by the so-called anchor effect. Thereby, the metal foil 51 and the base material 30 are firmly joined. And the laminated body by which the base material 30, the holding layer 31, the dark film 52, and the metal foil 51 were laminated | stacked in this order as is shown by FIG.

  Next, as shown in FIG. 10, a resist pattern 55 is provided on the metal foil 51. The resist pattern 55 is a pattern corresponding to the pattern of the conductive pattern 40 to be formed. In the method described here, the resist pattern 55 is provided only on the portion finally forming the conductive pattern 40. The resist pattern 55 can be formed by patterning using a known photolithography technique.

  Next, as shown in FIG. 11, the metal foil 51 including the dark color film 52 is etched (corrosion processed) using the resist pattern 55 as a mask. By this etching, the metal foil 51 including the dark color film 52 is patterned into a pattern substantially the same as the resist pattern 55. As a result, the conductive metal layer 48 and the dark color layer 49 that form the conductive thin wire 41 are formed from the patterned metal foil 51. As the corrosive liquid used for the etching process, a known corrosive liquid can be appropriately selected and used depending on the material of the metal foil 51 and the dark film 52 (when the dark film 52 is present). For example, when the metal foil 51 is copper and the dark color film 52 is copper (II) oxide (CuO), both the metal foil 51 and the dark color film 52 use ferric chloride aqueous solution, or the metal foil 51 part (copper). Can use ferric chloride aqueous solution, and dilute hydrochloric acid can be used for the dark film 52 (copper (II) oxide) portion.

Here, in general, compared with the conductive metal layer 48 made of a metal material, the dark color layer 49 made of an oxide or sulfide of the metal material is less likely to be eroded by etching. Therefore, lateral erosion due to side etching proceeds more in the conductive metal layer 48 than in the dark color layer 49. Further, also in the conductive metal layer 48, side erosion is more likely to proceed due to side etching in a region separated from the dark color layer 49 than in a region near the dark color layer 49. For this reason, the conductive fine wire 41 has a width that changes so as to decrease from the substrate 30 side toward the resist pattern 55 side by selecting an etching solution, adjusting the etching time, or the like, that is, having a tapered cross-sectional shape. Can be produced. Similarly, the widths W _a and W _c of the first surface (front end surface) 41a and the width W _{b of} the second surface (base end surface) 41b of the conductive thin wire 41 are selected by selecting an etching solution and adjusting the etching time. , W _d can be formed to a desired width.

  Thereafter, the resist pattern 62 is removed, and the conductive pattern sheet 20 shown in FIG. 12 is produced.

  Finally, the glass plate 11, the bonding layer 13, the conductive pattern sheet 20, the bonding layer 14, and the glass plate 12 are superposed in this order, and heated and pressurized. In the example shown in FIG. 13, first, the bonding layer 13 is temporarily bonded to the glass plate 11, and the bonding layer 14 is temporarily bonded to the glass plate 12. Next, the glass plate 11 and the conductive pattern sheet on which the bonding layer 13 is temporarily bonded so that the side on which the bonding layers 13 and 14 of the glass plates 11 and 12 are temporarily bonded faces the conductive pattern sheet 20 respectively. 20. The glass plate 12 to which the bonding layer 14 is temporarily bonded is superposed in this order, and heated and pressurized. Thereby, the glass plate 11, the electroconductive pattern sheet 20, and the glass plate 12 are joined via the joining layers 13 and 14, and the heat generating plate 10 shown in FIG. 3 is manufactured.

The heat generating plate 10 of the present embodiment described above is disposed between the pair of glass plates 11 and 12, the pair of glass plates 11 and 12, the conductive pattern 40 including the conductive thin wires 41, and the conductive property. Bonding layers 13 and 14 disposed between the pattern 40 and at least one of the pair of glass plates 11 and 12, and the conductive thin wire 41 of the conductive pattern 40 is one of the pair of glass plates 11 and 12. The first surface 41a facing the second surface 41b and the second surface 41b facing the other of the pair of glass plates 11 and 12, the width of the first surface 41a of the conductive thin wire 41 is W _a (μm), conductive When the width of the second surface 41b of the thin conductive wire 41 is W _b (μm) and the cross-sectional area of the conductive thin wire 41 is S _a (μm ² ), the following relationships (a) and (b) are satisfied.
0 <| W _a −W _b | ≦ 10 (a)
S _a ≧ 10 (b)

Moreover, the conductive pattern sheet 20 of the present embodiment described above includes the base material 30 and the conductive pattern 40 provided on the base material 30 and including the conductive thin wires 41. The conductive thin wire 41 has a base end surface 41b forming a surface on the base material 30 side and a tip end surface 41a opposite to the base end surface 41b, and the width of the tip end surface 41a of the conductive thin wire 41 is set to W _c (μm ), When the width of the base end face 41b of the conductive thin wire 41 is W _d (μm) and the cross-sectional area of the conductive thin wire 41 is S _b (μm ² ), the following relationships (c) and (d) Fulfill.
0 <| W _c −W _d | ≦ 10 (c)
S _b ≧ 10 (d)

According to the heat generating plate 10 and the conductive pattern sheet 20 as described above, the maximum width W of the conductive thin wire 41 (W _b , W _d in the examples shown in FIGS. 3 and 7) is reduced and appropriate. It is possible to ensure a sufficient cross-sectional area to obtain conductivity. Thereby, the appropriate electroconductivity of the electroconductive pattern 40 can be obtained, making the electroconductive pattern 40 invisible effectively.

  Note that various modifications can be made to the above-described embodiment. Hereinafter, modified examples will be described with reference to the drawings as appropriate. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as in the above embodiment. A duplicate description is omitted.

  With reference to FIGS. 14-18, the modification of the manufacturing method of the heat generating plate 10 is demonstrated. 14 to 18 are cross-sectional views sequentially showing modifications of the method for manufacturing the heat generating plate 10.

  First, the conductive pattern sheet 20 is produced. The conductive pattern sheet 20 can be produced by the method described in the example of the method for producing the heating plate 10 described above.

  Next, the glass plate 11, the bonding layer 13, and the conductive pattern sheet 20 are superposed in this order, and heated and pressurized. In the example shown in FIG. 14, first, the bonding layer 13 is temporarily bonded to the glass plate 11. Next, the glass plate 11 on which the bonding layer 13 is temporarily bonded is disposed so that the side on which the bonding layer 13 of the glass plate 11 is temporarily bonded faces the conductive pattern sheet 20. Superposed from the pattern 40 side, heated and pressurized. Thereby, as shown in FIG. 15, the glass plate 11 and the conductive pattern sheet 20 are bonded (temporary bonding or main bonding) via the bonding layer 13.

  Next, as shown in FIG. 16, the substrate 30 of the conductive pattern sheet 20 is removed. For example, when the holding layer 31 is formed so as to include a release layer, the substrate 30 of the conductive pattern sheet 20 can be peeled from the conductive pattern 40 and the bonding layer 13 using this release layer.

  As the release layer, for example, an interfacial release type release layer, an interlayer release type release layer, a cohesive release type release layer, or the like can be used. As the interface peeling type peeling layer, a peeling layer having relatively low adhesion to the conductive pattern 40 and the bonding layer 13 as compared with the adhesion to the substrate 30 can be suitably used. Examples of such a layer include a silicone resin layer, a fluororesin layer, and a polyolefin resin layer. In addition, a release layer that has relatively low adhesion to the substrate 30 as compared with the adhesion to the conductive pattern 40 and the bonding layer 13 can also be used. As the delamination type delamination layer, a delamination that includes a plurality of layers of film and has relatively low adhesion between the plurality of delaminations compared to the adhesion between the conductive pattern 40 and the bonding layer 13 and the substrate 30. A layer can be illustrated. Examples of the cohesive release type release layer include a release layer in which a filler as a dispersed phase is dispersed in a base resin as a continuous phase.

  When an interfacial release type release layer having a layer having relatively low adhesion to the conductive pattern 40 and the bonding layer 13 as compared to the adhesion to the substrate 30 is used as the release layer, the release layer and the conductive layer are electrically conductive. The peeling phenomenon occurs between the conductive pattern 40 and the bonding layer 13. In this case, it is possible to prevent the release layer from remaining on the conductive pattern 40 and the bonding layer 13 side. That is, the base material 30 is removed together with the release layer. When the substrate 30 and the release layer are thus removed, the bonding layer 13 is exposed in the opening region 44 of the conductive pattern 40.

  On the other hand, in the case where an interfacial release type release layer having relatively low adhesiveness to the substrate 30 as compared with the adhesiveness to the conductive pattern 40 and the bonding layer 13 is used as the release layer, the release layer A peeling phenomenon occurs between the layer and the substrate 30. A delamination type delamination that has a plurality of layers as a delamination layer and has relatively low adhesion between the plurality of layers compared to the adhesion between the conductive pattern 40 and the bonding layer 13 and the substrate 30. When a layer is used, a peeling phenomenon occurs between the plurality of layers. In the case of using an agglomerated exfoliation type release layer in which a filler as a dispersed phase is dispersed in a base resin as a continuous phase, an exfoliation phenomenon due to a cohesive failure occurs in the exfoliation layer.

  Finally, the glass plate 11, the bonding layer 13, the conductive pattern 40, the bonding layer 14, and the glass plate 12 are superposed in this order, and heated and pressurized. In the example shown in FIG. 17, first, the bonding layer 14 is temporarily bonded to the glass plate 12. Next, the glass plate 11, the conductive pattern 40, the bonding layer 13, and the bonding layer 14 are temporarily set so that the side on which the bonding layer 14 of the glass plate 12 is temporarily bonded faces the conductive pattern 40 and the bonding layer 13. The bonded glass plates 12 are superposed in this order, and heated and pressurized. Thereby, the glass plate 11, the conductive pattern 40, and the glass plate 12 are joined (main joining) via the joining layers 13 and 14, and the heat generating plate 10 shown in FIG. 18 is manufactured.

  According to the heat generating plate 10 shown in FIG. 18, the heat generating plate 10 can be made not to include the base material 30. Thereby, the thickness of the heat generating plate 10 as a whole can be reduced. In addition, the number of interfaces in the heat generating plate 10 can be reduced. Accordingly, it is possible to suppress a decrease in optical characteristics, that is, a decrease in visibility.

  Next, another modification of the method for manufacturing the heat generating plate 10 will be described with reference to FIGS. 19 and 20. FIGS. 19 and 20 are cross-sectional views sequentially showing another modification of the method for manufacturing the heat generating plate 10.

  First, the glass plate 11 and the conductive pattern sheet 20 are bonded (temporarily bonded) via the bonding layer 13 by the same process as the modified example of the manufacturing method of the heating plate 10 described above. The base material 30 is removed. That is, the glass plate 11, the conductive pattern 40, and the bonding layer 13 which are described with reference to FIG. 16 in the modification of the method for manufacturing the heat generating plate 10 are obtained.

  Next, as shown in FIG. 19, the glass plate 11, the bonding layer 13, the conductive pattern 40, and the glass plate 12 are superposed in this order, and heated and pressurized. Thereby, the glass plate 11 and the conductive pattern 40 are bonded (main bonding) via the bonding layer 13, and the glass plate 11 and the glass plate 12 are bonded (main bonding) via the bonding layer 13. . Then, the heat generating plate 10 shown in FIG. 20 is manufactured.

  According to the heat generating plate 10 illustrated in FIG. 20, the heat generating plate 10 can be configured not to include the base material 30 and the bonding layer 14. Thereby, the thickness of the heat generating plate 10 as a whole can be further reduced. In addition, the number of interfaces in the heat generating plate 10 can be further reduced. Therefore, it is possible to more effectively suppress a decrease in optical characteristics, that is, a decrease in visibility. In addition, since the conductive pattern 40 and the glass plate 12 are in contact, the heating efficiency of the glass plate 12 by the conductive pattern 40 can be increased.

  In the above-described embodiment, each of the plurality of connection elements 45 included in the conductive pattern 40 has a straight line shape (straight line portion) when viewed from the normal direction of the plate surface of the heat generating plate 10, but is not limited thereto. Instead, at least a part of the plurality of connection elements 45 may have a shape other than a straight line shape, for example, a curved line shape or a polygonal line shape when viewed from the normal direction of the plate surface of the heat generating plate 10. Specifically, it may have a shape such as an arc shape, a parabolic shape, a wavy shape, a zigzag shape, or a combination of a curve and a straight line. In particular, the connection element 45 connecting the two branch points 43 as a straight line (straight line segment) is less than 20% of the plurality of connection elements 45, that is, 80% or more of the plurality of connection elements 45. Preferably have a shape other than a straight line (straight line).

  According to the conductive pattern 40 including the connection element 45 having a shape other than a straight line (straight line), light incident on the side surface of the connection element 45 having a curved shape, a broken line shape, or the like is transmitted on the side surface. Diffuse reflection. Thereby, light incident on the side surface of the connection element 45 from a certain direction (light of the headlight of the oncoming vehicle, sunlight, etc.) may be reflected in a certain direction on the side surface corresponding to the incident direction. It is suppressed. Therefore, it can suppress that this reflected light is visually recognized by observers, such as a driver, and the conductive pattern 40 which has the connection element 45 is visually recognized by an observer. As a result, the deterioration of the visibility through the window glass by the observer due to the visual recognition of the conductive pattern 40 can be suppressed.

  Further, in the above-described embodiment, the conductive pattern 40 is determined based on the Voronoi diagram, that is, a large number of opening regions 44 are arranged in a shape and a pitch having no repeated regularity (periodic regularity). However, the conductive pattern 40 is not limited to such a pattern, and the conductive pattern 40 is a pattern in which opening regions having the same shape such as a triangle, a quadrangle, and a hexagon are regularly arranged, and an opening region having an irregular shape. Various patterns such as a pattern in which are regularly arranged may be used.

  The heat generating plate 10 may be used for a rear window, a side window, or a sunroof of the automobile 1. In addition, transparent windows or doors of vehicles other than automobiles such as railway vehicles, aircraft, ships and spacecrafts, transparent windows or doors of buildings, storage windows or doors of refrigerators, display boxes, cupboards, etc. You may use for a part.

  Furthermore, the heat generating plate 10 can be used not only for a vehicle but also for a part that divides the room from the outside, for example, a transparent part of a building or a store, a window or door of a house, or the like.

  In addition, although the some modification with respect to embodiment mentioned above was demonstrated above, naturally, it is also possible to apply combining several modifications suitably.

DESCRIPTION OF SYMBOLS 1 Automobile 5 Front window 7 Power supply 10 Heat generating plate 11 Glass plate 12 Glass plate 13 Joining layer 14 Joining layer 15 Wiring part 16 Connection part 20 Conductive pattern sheet 30 Base material 31 Holding layer 40 Conductive pattern 41 Conductive thin wire 41a 1st Surface (tip surface)
41b Second surface (base end surface)
41c Side surface 41d Side surface 43 Branch point 44 Opening region 45 Connection element 48 Conductive metal layer 49 Dark color layer 51 Metal foil 52 Dark color film 55 Resist pattern

Claims (10)

A heating plate that generates heat when a voltage is applied,
A pair of glass plates;
A conductive pattern disposed between the pair of glass plates and including a conductive fine wire; and
A bonding layer disposed between the conductive pattern and at least one of the pair of glass plates,
The conductive thin wire of the conductive pattern has a first surface facing one of the pair of glass plates, and a second surface facing the other of the pair of glass plates,
When the width of the first surface of the conductive thin wire is Wa (μm), the width of the second surface of the conductive thin wire is Wb (μm), and the cross-sectional area of the conductive thin wire is Sa (μm 2). A heating plate that satisfies the following relationships (a) and (b).
0 <| Wa−Wb | ≦ 10 (a)
Sa ≧ 10 (b)   The heat generating plate according to claim 1, wherein the conductive pattern is formed by patterning a conductive layer by etching. The conductive pattern has a pattern defining a plurality of opening regions;
The heat generating plate according to claim 1, wherein the conductive pattern includes a plurality of connecting elements extending between two branch points to define the opening region.   The heat generating plate according to claim 3, wherein in the conductive pattern, the average number of the connection elements extending from one branch point is greater than 3.0 and less than 4.0. The conductive patterns each include an open area surrounded by four, five, six and seven connecting elements;
5. The heat generating plate according to claim 3, wherein among the opening regions included in the conductive pattern, the opening region surrounded by six connection elements is the largest.   6. The heat generating plate according to claim 3, wherein at least a part of the plurality of connecting elements has a curved or broken line shape when viewed from the normal direction of the plate surface of the heat generating plate. The conductive pattern includes a plurality of the conductive thin wires,
The heating plate according to claim 1 or 2, wherein the plurality of conductive thin wires are arranged apart from each other in a direction non-parallel to the extending direction of the conductive thin wires.   The heat generating plate according to claim 7, wherein the conductive thin wires adjacent in the non-parallel direction are connected by a connection line. A conductive pattern sheet used for a heat generating plate that generates heat when a voltage is applied,
A substrate;
A conductive pattern provided on the base material and including a conductive fine wire; and
The conductive thin wire of the conductive pattern has a base end surface forming a surface on the substrate side, and a front end surface facing the base end surface,
When the width of the distal end surface of the conductive thin wire is Wc (μm), the width of the base end surface of the conductive thin wire is Wd (μm), and the cross-sectional area of the conductive thin wire is Sb (μm2), A conductive pattern sheet satisfying the relationship (c) and (d).
0 <| Wc−Wd | ≦ 10 (c)
Sb ≧ 10 (d)   The vehicle provided with the heat generating plate as described in any one of Claims 1-8.

Images