JP2019197727A - Heating plate, conductor-equipped film, and manufacturing method of heating plate - Google Patents

Abstract

To suppress generation of distortion in the field of view through a heating plate.SOLUTION: A heating plate 10 includes a first substrate 11 and a second substrate 12 that are spaced apart in a first direction d1, a heating conductor 40 disposed between the first substrate 11 and the second substrate 12, and a bonding layer 30 that bonds the first substrate 11 and the second substrate 12. The heating conductor 40 generates heat when voltage is applied thereto. The heating conductor 40 is adjacent to the bonding layer 30. The heating conductor 40 is in contact with the first substrate 11. The surface roughness Sz on the side in contact with the first substrate 11 of the heating conductor 40 is 3.0 μm or less.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heating plate, a film with a conductor, and a method for manufacturing the heating plate.

  Conventionally, a heat generating plate in which a heat generating conductor is disposed between a pair of substrates such as a glass substrate has been widely used. This heat generating plate is used, for example, in a defroster (defrosting device) used for a window glass of a moving body. The heat generating plate generates heat by resistance heating when energized to the heat generating conductor (see, for example, Patent Document 1 and Patent Document 2). The heating plate applied to the window glass of the moving body removes fogging of the window glass, melts snow and ice attached to the window glass, or drops of water attached to the window glass by raising the temperature of the heat generating conductor. By evaporating, the field of view of the occupant of the moving body can be secured.

JP 2013-173402 A JP-A-8-72674 JP-A-9-207718 JP, 2006-102056, A

  By the way, the heat generating plate has a bonding layer between a pair of substrates in order to bond the pair of substrates. When such a heat generating plate is heated, distortion (distortion) may occur in the field of view through the heat generating plate. As a result of intensive studies by the present inventors, it has been found that such strain is caused by a decrease in refractive index in a part of the bonding layer due to heat generated from the heat generating conductor. The portion of the bonding layer close to the heat generating conductor is likely to have a higher temperature than the other portions, and the refractive index is lowered by changing the material of the bonding layer at the portion where the temperature of the bonding layer is high. When a difference in refractive index occurs in the bonding layer, light transmitted through the bonding layer is refracted according to the refractive index difference. It has been found that distortion occurs in this way.

  The present invention is based on the above knowledge, and an object thereof is to suppress the occurrence of distortion in a field of view through a heat generating plate.

The first heat generating plate of the present invention is
A first substrate and a second substrate spaced apart in a first direction;
A heating conductor disposed between the first substrate and the second substrate and generating heat when a voltage is applied;
A bonding layer for bonding the first substrate and the second substrate;
The heating conductor is adjacent to the bonding layer;
The heat generating conductor has a surface in contact with the first substrate.

The second heat generating plate of the present invention is
A first substrate and a second substrate spaced apart in a first direction;
A heating conductor disposed between the first substrate and the second substrate and generating heat when a voltage is applied;
A bonding layer for bonding the first substrate and the second substrate;
The heating conductor is adjacent to the bonding layer;
The heating conductor is in contact with the first substrate;
The surface roughness Sz on the side in contact with the first substrate of the heat generating conductor is 3.0 μm or less.

In the first and second heating plates of the present invention,
The heating conductor includes a plurality of linear conductors,
In the cross section along the direction orthogonal to the longitudinal direction of the linear conductor, the linear conductor may have a surface in contact with the first substrate.

  In the first and second heat generating plates of the present invention, the surface roughness Sz of the surface on the side adjacent to the bonding layer of the heat generating conductor may be larger than 1.0 μm.

In the first and second heating plates of the present invention,
The heating conductor includes a plurality of linear conductors,
The linear conductor may include a conductive layer and a dark color layer provided on at least a part of the surface of the conductive layer.

  In the first and second heat generating plates of the present invention, the dark color layer may be provided on at least a side of the linear conductor facing the first substrate.

  In the first and second heat generating plates of the present invention, the dark color layer may cover both sides of the surface of the conductive layer and a surface facing the second substrate.

In the first and second heating plates of the present invention,
The heating conductor includes a plurality of linear conductors,
The line width of each linear conductor is 2 μm or more and 20 μm or less,
The thickness of each linear conductor may be 1 μm or more and 30 μm or less.

In the first and second heating plates of the present invention,
The heating conductor includes a plurality of linear conductors,
In each position of the linear conductor, the ratio of the height to the line width of the linear conductor may be not less than 0.5 and not more than 1.8.

In the first and second heating plates of the present invention,
The heat generating conductor includes a plurality of linear conductors arranged in a pattern defining a plurality of opening regions,
The average distance between the centers of gravity of the opening regions may be not less than 100 μm and not more than 10,000 μm.

In the first and second heating plates of the present invention,
The heating conductor includes a plurality of linear conductors extending in one direction and arranged with a gap in a direction non-parallel to the one direction,
The average length of the gaps along the direction not parallel to the one direction may be not less than 100 μm and not more than 12000 μm.

  In the first and second heat generating plates of the present invention, the resistance of the heat generating conductor may be not less than 0.1Ω / □ and not more than 1Ω / □.

In the first and second heating plates of the present invention,
The heating conductor includes a plurality of linear conductors,
The bonding layer includes a first portion adjacent to the heat-generating conductor, and a second portion positioned away from the first portion in the first direction,
The ratio of the thickness of the first portion to the height of the linear conductor may be 3 or more and 8 or less.

  In the first and second heat generating plates of the present invention, the ratio of the thickness of the second portion to the height of the linear conductor may be 20 or more and 130 or less.

In the first and second heating plates of the present invention,
The heating conductor includes a plurality of linear conductors,
The cross-sectional shape of the linear conductor may be a trapezoidal shape.

  In the first and second heat generating plates of the present invention, the cross-sectional shape of the linear conductor is a trapezoidal shape that is not the shorter side of two opposite sides that are parallel to the side in contact with the first substrate. May be.

  In the first and second heat generating plates of the present invention, the cross-sectional shape of the linear conductor is a trapezoidal shape that is the longer side of the two opposite sides that are parallel to the side in contact with the first substrate. May be.

In the first and second heating plates of the present invention,
The heating conductor includes a plurality of linear conductors,
The cross-sectional shape of the linear conductor may be narrower at a position closest to the second substrate than a position in contact with the first substrate.

In the first and second heating plates of the present invention,
The heating conductor includes a plurality of linear conductors,
The cross-sectional shape of the linear conductor may be wider at a position closest to the second substrate than a position in contact with the first substrate.

The film with a conductor of the present invention is a film with a conductor used for a heating plate,
A heating conductor that generates heat when a voltage is applied;
A substrate film for supporting the heat-generating conductor,
The base film has heat sealability.

The method for producing the heating plate of the present invention is as follows.
Providing a conductive film on a base film having heat-sealability;
Patterning the conductive film;
A step of pressing and heating the first substrate and the second substrate toward each other in a state where the base film is disposed between the first substrate and the second substrate.

  According to the present invention, it is possible to suppress the occurrence of distortion in the field of view through the heat generating plate.

FIG. 1 is a perspective view schematically illustrating a moving body provided with a heat generating plate for explaining an embodiment. In particular, FIG. 1 schematically shows an automobile provided with a front window formed of a heat generating plate as an example of a moving body. FIG. 2 is a view showing the heat generating plate from the normal direction of the plate surface. 3 is a cross-sectional view of the heat generating plate taken along line AA in FIG. FIG. 4 is a plan view showing the heating conductor of the present embodiment from the normal direction of the plate surface of the heating plate, and is a plan view showing an example of the heating conductor. FIG. 5 is a plan view showing the heat generating conductor of the present embodiment from the normal direction of the plate surface of the heat generating plate, and is a plan view showing another example of the heat generating conductor. FIG. 6 is a diagram for explaining the operation of the heat generating plate of FIG. FIG. 7 is a diagram for explaining an example of a method for manufacturing a heat generating plate. 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 another example of the method of manufacturing the heat generating plate. FIG. 14 is a diagram for explaining another example of the method of manufacturing the heat generating plate. FIG. 15 is a cross-sectional view showing a modification of the cross-sectional shape of the linear conductor included in the heat generating plate. FIG. 16 is a cross-sectional view showing another modification of the cross-sectional shape of the linear conductor included in the heat generating plate. FIG. 17 is a cross-sectional view showing a modification of the linear conductor included in the heat generating plate. FIG. 18 is a diagram for explaining the operation of a conventional heat generating plate.

  Hereinafter, an embodiment 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, “film with conductor” is a concept including a member that can be called a plate or a sheet. Therefore, “film with conductor” is “plate with conductor (substrate)” or “with conductor”. It cannot be distinguished from a member called a “sheet” 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 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.

  1-18 is a figure for demonstrating one Embodiment and a modification. Among these, FIG. 1 is a diagram schematically showing an automobile provided 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. It is a figure which shows the cross section of the heat generating board along the -A line.

  As shown in FIG. 1, an automobile 1 as an example of a moving body 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. 3 is a cross-sectional view corresponding to the line AA of the heat generating plate 10 of FIG. In the example shown in FIG. 3, the heating plate 10 is disposed between the first substrate 11 and the second substrate 12 that are spaced apart in the first direction d1 and the first substrate 11 and the second substrate 12. And the bonding layer 30 for bonding the first substrate 11 and the second substrate 12 to each other. In the illustrated example, the first direction coincides with the thickness direction of the heat generating plate 10 and further coincides with the normal direction to the plate surface of the heat generating plate 10. In the example shown in FIG. 3, the heating conductor 40 is disposed at the end of the bonding layer 30 in the first direction d1. In the example shown in FIGS. 1 and 2, the heat generating plate 10 is curved, but in the other drawings, the heat generating plate 10, the first substrate 11, and the like are shown in order to simplify the illustration and facilitate understanding. The second substrate 12 is illustrated in a flat plate shape. 3 and 4 are views showing a cross section along a direction perpendicular to the longitudinal direction of the linear conductor 41 of the heat generating conductor 40 described later.

  As well shown in FIGS. 1 and 2, the heat generating plate 10 has a wiring portion 15 for energizing the heat generating conductor 40. In the illustrated example, a power source 7 such as a battery energizes the heat generating conductor 40 from the wiring portion 15 through the bus bar 45 of the heat generating conductor 40, and the heat generating conductor 40 is heated by resistance heating. The heat generated in the heat generating conductor 40 is transmitted to the first substrate 11 and the second substrate 12, and the first substrate 11 and the second substrate 12 are warmed. Thereby, the cloudiness by the dew condensation adhering to the 1st board | substrate 11 and the 2nd board | substrate 12 can be removed. Further, when snow and ice are attached to the first substrate 11 and the second substrate 12, the snow and ice can be melted. Therefore, a passenger | crew's visual field is ensured favorable. In addition, although illustration is omitted, normally, in the wiring portion 15, a switch is inserted (connected in series) between the power source 7 and the bus bar 45 of the heat generating conductor 40. Then, only when the heating plate 10 needs to be heated, the switch is closed and the heating conductor 40 is energized.

  Hereinafter, each component of the heat generating plate 10 will be described.

  First, the first substrate 11 and the second substrate 12 will be described. When the first substrate 11 and the second substrate 12 are used for a front window of an automobile as in the example shown in FIG. 1, it is preferable to use a substrate having a high visible light transmittance so as not to disturb the sight of the passenger. Examples of the material of the first substrate 11 and the second substrate 12 include soda lime glass and blue plate glass. The visible light transmittance of the first substrate 11 and the second substrate 12 is preferably 90% or more. Here, the visible light transmittance of the first substrate 11 and the second substrate 12 is measured at a wavelength of 380 nm to 780 nm using a spectrophotometer (manufactured by Shimadzu Corporation “UV-3100PC”, JIS K 0115 compliant product). It is specified as the average value of transmittance at each wavelength when measured within the range. Note that the visible light transmittance of a part of the first substrate 11 and the second substrate 12 may be lowered by coloring or the like. 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 1st board | substrate 11 and the 2nd board | substrate 12 have thickness of 1 mm or more and 5 mm or less. With such a thickness, the first substrate 11 and the second substrate 12 excellent in strength and optical characteristics can be obtained. The first substrate 11 and the second substrate 12 may be configured identically with the same material, or may be different from each other in at least one of the material and configuration.

  Next, the bonding layer 30 will be described. The bonding layer 30 is disposed between the first substrate 11 and the second substrate 12 and bonds the first substrate 11 and the second substrate 12. As such a bonding layer 30, a layer made of a material having various adhesiveness or tackiness can be used. Moreover, it is preferable to use the bonding layer 30 having a high visible light transmittance. As a typical joining layer, the layer which consists of polyvinyl butyral (PVB) can be illustrated. As shown in FIG. 3, the bonding layer 30 has a first portion 31 and a second portion 32. The first portion 31 is adjacent to the heat generating conductor 40. The second portion 32 is located so as to be shifted from the first portion 31 in the first direction d1. The first portion 31 is in contact with the first substrate 11, and the second portion 32 is in contact with the second substrate 12.

  The thickness of the bonding layer 30, that is, the length in the first direction d1, is, for example, not less than 20 μm and not more than 1000 μm. If the bonding layer 30 has a sufficient thickness, it is possible to prevent the fragments of the first substrate 11 from scattering when the heat generating plate 10 is damaged, and the fragments of the first substrate 11 and the like. Can be prevented from penetrating the heat generating plate 10.

  The thickness T1 of the first portion 31, that is, the length in the first direction d1, is preferably shorter than the thickness T2 of the second portion, that is, the length in the first direction d1. As a specific example, the thickness T1 of the first portion 31 can be set to 20 μm or more and 100 μm or less, and further can be set to 40 μm or more and 80 μm or less. In addition, the thickness T2 of the second portion 32 can be set to, for example, 150 μm or more and 1600 μm or less.

  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. Moreover, you may make it one functional layer exhibit two or more functions. For example, some function may be imparted to at least one of the first substrate 11 and the second substrate 12 and the bonding layer 30 of the heating plate 10. Examples of functions that can be imparted to the heat generating 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 an antifouling function. A function etc. can be illustrated.

  Next, the heat generating conductor 40 will be described with reference to FIGS. 4 and 5. 4 and 5 are plan views of the heat generating conductor 40 as viewed from the normal direction of the plate surface of the heat generating plate 10. FIG. 4 shows an example of an arrangement pattern of the linear conductors 41 that form the heat generating conductor 40, and FIG. 5 shows another arrangement pattern of the linear conductors 41 that form the heat generating conductor 40. An example is shown.

  The heat generating conductor 40 has a pair of bus bars 45 and a plurality of linear conductors 41 disposed between the pair of bus bars 45. The pair of bus bars 45 are spaced apart from each other in the second direction d2 and are electrically connected to the corresponding wiring portions 15 respectively. The second direction d2 is a direction along the plate surface of the heat generating plate 10, and is orthogonal or substantially orthogonal to the first direction d1 in the illustrated example. Between the pair of bus bars 45, the voltage of the power source 7 connected to the wiring portion 15 is applied. The linear conductor 41 is connected to a pair of bus bars 45 at both ends thereof. Therefore, the linear conductor 41 electrically connects the pair of bus bars 45. The linear conductor 41 generates heat by resistance heating when a voltage is applied via the wiring portion 15 and the bus bar 45. Then, the heat is transmitted to the first substrate 11 and the second substrate 12 through the bonding layer 30, so that the first substrate 11 and the second substrate 12 are warmed.

  In order to cause the heat generating conductor 40 to generate heat with an appropriate heat generation amount, it is preferable to adjust the sheet resistance of the heat generating conductor 40 in accordance with the applied voltage. For example, when the applied voltage is about 12 V, it is preferably 0.1 Ω / □ or more and 1 Ω / □ or less, and when the applied voltage is about 48 V, it is preferably 1 Ω / □ or more and 13 Ω / □ or less. Therefore, in the range of the applied voltage of 12 to 48 V, the sheet resistance is preferably 0.1Ω / □ or more and 13Ω / □ or less. If the resistance of the heat generating conductor 40 is too large, the amount of heat generated in the heat generating conductor 40 is insufficient, and the first substrate 11 and the second substrate 12 cannot be appropriately heated. Further, if the resistance of the heat generating conductor 40 is too small, the amount of heat generated in the heat generating conductor 40 becomes too large, and uneven heat generation is likely to occur between the region near the linear conductor 41 and other regions. Become.

  The heating conductor 40 can be arranged in various patterns. As an example, as shown in FIG. 4, the heating conductor 40 is formed by arranging linear conductors 41 in a mesh pattern that defines a plurality of opening regions 47. The heating conductor 40 includes a plurality of connecting elements 48 extending between the two branch points 46 and defining an open region 47. That is, the linear conductor 41 of the heating conductor 40 is configured as a collection of a plurality of connection elements 48 that form the branch points 46 at both ends. As shown in FIG. 4, the mesh pattern may be an irregular mesh pattern in which the shape and size of each opening region 47 is not congruent and does not have a constant repetition period in the plane, or the shape of each opening region 47 Further, the mesh pattern may be a periodic lattice having a congruent size and the opening region 47 having a constant repetition period in a plane.

  In the heat generating conductor 40 shown in FIG. 4, if the distance between the centers of gravity of the two adjacent opening regions 47 is too large, heat generation unevenness occurs in the heat generating conductor 40, so the average distance between the centers of gravity of the opening regions 47 is increased. Is preferably 10,000 μm or less, more preferably 7000 μm or less, and even more preferably 5000 μm or less. Further, if the distance between the centers of gravity of the two adjacent opening regions 47 is too small, the transmittance is deteriorated and the transparency is deteriorated. Therefore, the average distance between the centers of gravity of the opening regions 47 is preferably 100 μm or more. .

  As another example of the pattern of the heat generating conductor 40, as shown in FIG. 5, the heat generating conductor 40 has a stripe pattern in which a plurality of linear conductors 41 connecting a pair of bus bars 45 are formed. It may be formed by arranging by. More specifically, the plurality of linear conductors 41 may be arranged with a gap 49 in a direction non-parallel to the second direction d2 while extending in the second direction d2.

  In the heat generating conductor 40 shown in FIG. 5, if the gap 49 is too large, heat generation unevenness occurs in the heat generating conductor 40. In other words, the size of the gap 49, in other words, the second direction that is the arrangement direction of the gaps 49. It is preferable that the average length along a direction parallel to d2 and, in other words, the average distance between adjacent linear conductors 41 is 12000 μm or less, preferably 7000 μm or less. Is more preferable and it is still more preferable that it is 3000 micrometers or less. Moreover, since the transmittance | permeability will deteriorate and transparency will be impaired when the clearance gap 49 is too small, it is preferable that the average of the distance between the adjacent linear conductors 41 is 100 micrometers or more.

  As shown in FIG. 3, the heat generating conductor 40 is embedded in the bonding layer 30. In the example shown in FIG. 3, the heat generating conductor 40 is disposed at the end of the bonding layer 30 in the first direction d <b> 1 in a state of being embedded in the bonding layer 30. That is, the heat generating conductor 40 is adjacent to the bonding layer 30. Further, the heat generating conductor 40 is in contact with the first substrate 11. Further, in the cross section shown in FIG. 3, the linear conductor 41 of the heat generating conductor 40 has a surface 40 a in contact with the first substrate 11. The surface roughness Sz of the surface 40a on the side in contact with the first substrate 11 of the heat generating conductor 40 is preferably 3.0 μm or less, more preferably 2.0 μm or less, and 1.0 μm. More preferably, it is as follows.

  In the example shown in FIG. 3, the surface roughness Sz of the surface 40b adjacent to the bonding layer 30 of the heat generating conductor 40 is preferably larger than 1.0 μm, and more than 3.0 μm. Is more preferable. The surface roughness Sz means Sz defined by ISO25178.

  Examples of the material for forming the linear conductor 41 and the bus bar 45 include gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, tungsten, and these. One or more of the alloys can be exemplified. The linear conductor 41 and the bus bar 45 may be formed using the same material, or may be formed using different materials.

  As described above, the linear conductor 41 can be formed using an opaque metal material. On the other hand, the ratio of the area not covered with the linear conductor 41, that is, the non-coverage ratio (opening ratio) is as high as about 70% to 99%. The line width of the linear conductor 41 is 2 μm or more and 20 μm or less. For this reason, the region where the linear conductor 41 is provided is grasped transparently as a whole, and the presence of the linear conductor 41 does not impair the transparency of the heat generating plate 10.

  In the example shown in FIG. 3, the linear conductor 41 has a rectangular cross section as a whole. As described above, the width W of the linear conductor 41, that is, the width W along the plate surface of the heat generating plate 10 is 2 μm or more and 20 μm or less, and the height (thickness) H, that is, the plate surface of the heat generating plate 10. The height (thickness) H along the normal line direction is preferably 1 μm or more and 30 μm or less. According to the linear conductor 41 having such dimensions, since the linear conductor 41 is sufficiently thinned, the linear conductor 41 can be effectively invisible.

  Further, at each position of the linear conductor 41, the ratio (H / W) of the height H to the line width W of the linear conductor 41 is preferably 0.5 or more and 1.8 or less. It is more preferably 7 or more and 1.5 or less, and further preferably 0.9 or more and 1.35 or less. The linear conductor 41 having such a dimensional ratio can be easily manufactured, and the width is too large with respect to the height so that the transparency is not impaired. Further, even when the linear conductor 41 having such a dimensional ratio is observed from the direction inclined in the normal direction of the heat generating plate 10, the width of the visually recognized linear conductor 41 is hardly changed. In other words, even when observed from a direction inclined in the normal direction of the heat generating plate 10, the transparency is hardly impaired.

  The ratio (T1 / H) of the thickness T1 of the first portion 31 of the bonding layer 30 to the height H of the linear conductor 41 is preferably 3 or more and 8 or less, and is 4 or more and 7 or less. Is more preferable. Furthermore, the ratio (T2 / H) of the thickness T2 of the second portion 32 of the bonding layer 30 to the height H of the linear conductor 41 is preferably 20 or more and 130 or less, and 60 or more and 110 or less. Is more preferable. In such a case, when the heat generating conductor 40 in the manufacturing process of the heat generating plate 10 to be described later is embedded in the first portion 31 (base film 21) of the bonding layer 30, air and the like are effectively suppressed. can do.

  Further, as shown in FIG. 3, the linear conductor 41 includes the first dark color layer 44 that covers the conductive layer 42 and the surfaces of the conductive layer 42 that face the first substrate 11 and both side surfaces. The second dark color layer 43 covering the surface of the conductive layer 42 facing the second substrate 12 may be included. In particular, the linear conductor 41 preferably includes at least a dark color layer that covers the surface of the first dark color layer 44 on the side facing the first substrate 11. The conductive layer 42 made of a metal material having excellent conductivity exhibits a relatively high reflectance. And if light is reflected by the conductive layer 42 which comprises the linear conductor 41, the reflected light will be visually recognized and may disturb a passenger | crew's visual field. Further, when the conductive layer 42 is visually recognized from the outside, the designability may be deteriorated. Therefore, the first dark color layer 44 and the second dark color layer 43 cover at least a part of the surface of the conductive layer 42. The first dark color layer 44 and the second dark color layer 43 may be layers having a visible light reflectance lower than that of the conductive layer 42, and are dark color layers such as black, for example. Specifically, the first dark color layer 44 and the second dark color layer 43 have a visible light reflectance of 15% or less, preferably 8% or less, more preferably 5% or less. The first dark color layer 44 and the second dark color layer 43 make it difficult for the conductive layer 42 to be visually recognized, thereby ensuring a good occupant's field of view. Moreover, the fall of the designability when seen from the outside can be prevented.

  In particular, since the surface of the surface 40b adjacent to the bonding layer 30 of the heat generating conductor 40 is rough, the first dark color formed on the side surface of the conductive layer 42 formed on the surface of the linear conductor 41. The layer 44 and the second dark color layer 43 are roughened.

  By the way, in the heat generating plate described in Patent Document 3, a heat generating conductor made of tungsten wire is disposed between two substrates while being supported by a transparent base film having heat sealability, and bonded. The layers were bonded to each substrate. The heating wire (wire) formed from such tungsten has a relatively high volume resistivity. On the other hand, in order to increase the amount of heat generated by resistance heating of the heating wire during energization, it is desirable to reduce the resistance of the heating wire. In consideration of securing the calorific value, it is difficult to form a heating wire made of tungsten extremely thin. Moreover, since a thin heating wire is easy to disconnect, it is difficult to process a heat generating plate with a high yield. For these reasons, the heating wire made of tungsten has been formed thick. For this reason, the heating wire contained in the heat generating plate is easily visible, and the visibility of the field of view through the heat generating plate is deteriorated.

  On the other hand, in the heat generating plate described in Patent Document 4, the heat generating conductor made of copper or the like and having a wire width of 10 μm or less was supported on a transparent substrate made of polyethylene terephthalate (PET) or the like. In the state, it was arrange | positioned between two joining layers, and was joined to each board | substrate with the joining layer. Therefore, it is difficult to visually recognize the heat generating conductor, and there is an effect in obtaining good transparency. However, when a voltage is applied to the heat generating conductor to heat the heat generating plate, distortion may occur in the field of view through the heat generating plate. The distortion can worsen the field of view through the heating plate.

  As a result of intensive studies by the present inventors, it has been found that such a strain occurs when a difference in refractive index occurs in the resin layer 130 as shown in FIG. Here, the resin layer 130 is a layer including a bonding layer and a transparent substrate. The refractive index of the resin layer 130 is more likely to change due to a temperature rise than the substrates 111 and 112 made of glass or the like. The inventors have also confirmed that the occurrence of the refractive index difference in the resin layer 130 is caused by uneven temperature in the resin layer 130. As a result of further studies by the present inventors, even if a voltage is applied to the heat generating conductor 40 to generate heat, the heat generation plate 10 can be prevented from generating distortion in the field of view through the heat generation plate 10. The heat generating plate 10 according to the present embodiment was devised so that it could be obtained.

  As shown in FIG. 18, in the cross section of the conventional heat generating plate 110 that does not include a transparent base material, when the heat generating conductor 140 generates heat, the peripheral region A2 that is in the vicinity of each linear conductor 141 of the heat generating conductor 140 is , More susceptible to heat than other areas. In other words, the peripheral area A2 of the linear conductor 141 is warmed more than other areas. That is, temperature unevenness occurs between the peripheral region A2 and other regions. In the peripheral region A2 of the heated linear conductor 141, the resin layer 130 is altered by heat. Due to the alteration, the refractive index of the resin layer 130 in the peripheral region A2 changes. Thus, a refractive index difference is generated between the peripheral region A2 of the resin layer 130 and the region other than the peripheral region A2. In accordance with this difference in refractive index, the light transmitted between the peripheral area A2 and the area other than the peripheral area A2 is refracted as indicated by solid arrows in FIG. When the light incident on the heat generating plate 110 is transmitted through the heat generating plate 110 in a state of generating heat, the light is greatly expanded and emitted as compared with a dotted arrow indicating non-refracted light. The emitted light spreads more as the region A2 where the resin layer 130 is deteriorated becomes larger. The light that passes through the heat generating plate 110 and is emitted greatly spreads, and thus distortion occurs in the field of view through the heat generating plate 110.

  On the other hand, in the example shown in FIG. 3, the heat generating conductor 40 has a surface 40 a in contact with the first substrate 11. If the heat generating conductor 40 has the surface 40 a in contact with the first substrate 11, the heat generated by the heat generating conductor 40 can be efficiently transferred to the first substrate 11. In particular, generally, the first substrate 11 made of glass or the like is easier to conduct heat than the bonding layer 30 made of resin or the like. That is, more heat is conducted to the first substrate 11. In other words, less heat is conducted to the bonding layer 30. For this reason, it is possible to reduce the peripheral region A1 that may be altered by heat. Since the light incident on the heat generating plate 10 is difficult to spread, the generation of distortion can be suppressed. Moreover, since heat is easily transmitted to the first substrate 11, the first substrate 11 can be efficiently heated. This is particularly effective when it is desired to efficiently generate heat only on one side of the heat generating plate 10 such as the outside of the front window 5 of the automobile 1 shown in FIG.

  In particular, the surface roughness Sz of the surface 40a on the side in contact with the first substrate 11 of the heat generating conductor 40 is preferably 3.0 μm or less, more preferably 2.0 μm or less, and even more preferably 1.0 μm. It is as follows. That is, the portion where the heat generating conductor 40 and the first substrate 11 are in contact with each other is large. In this case, the heat generated by the heat generating conductor 40 can be efficiently transmitted to the first substrate 11. That is, more heat is conducted to the first substrate 11. In other words, less heat is conducted to the bonding layer 30. For this reason, it is possible to further reduce the peripheral region A1 that may be altered by heat. Since the light incident on the heating plate 10 is difficult to spread, the generation of distortion can be further suppressed. Moreover, since heat is easily transmitted to the first substrate 11, the first substrate 11 can be efficiently heated. This is particularly effective when it is desired to efficiently generate heat only on one side of the heat generating plate 10 such as the outside of the front window 5 of the automobile 1 shown in FIG.

  The surface roughness Sz of the surface 40b adjacent to the bonding layer 30 of the heat generating conductor 40 is preferably greater than 1.0 μm, and more preferably 3.0 μm or more. In other words, the portion where the heat generating conductor 40 and the bonding layer 30 are in contact with each other is preferably small. In this case, the heat generated in the heat generating conductor 40 is not easily transmitted to the bonding layer 30 due to heat conduction. For this reason, it is possible to further reduce the peripheral region A1 that may be altered by heat. Since the light incident on the heating plate 10 is difficult to spread, the generation of distortion can be further suppressed. Further, when the surface of the heat generating conductor 40 becomes rough, the heat generated in the heat generating conductor 40 is easily transmitted by radiation (radiation). According to the transfer of heat by radiation, it is possible to avoid the local heating of the heat generating plate 10 and realize more uniform heating than the transfer by heat conduction. For this reason, it is possible to further reduce the peripheral region A1 that may be altered by heat. Since the light incident on the heating plate 10 is difficult to spread, the generation of distortion can be further suppressed. Further, according to the heat transfer by radiation, the first substrate 11 and the second substrate 12 can be efficiently heated, or snow, water droplets, etc. adhering to the surface of the heating plate 10 can be directly heated. That is, the function of the heat generating plate 10 can be exhibited more efficiently.

  The linear conductor 41 preferably includes the first dark color layer 44 or the second dark color layer 43 provided on at least a part of the surface thereof. In particular, the linear conductor 41 preferably includes a first dark color layer 44 provided on the side facing the first substrate 11. When the heat generating plate 10 is applied to, for example, the front window 5 of the automobile 1 shown in FIG. 1, if the first dark color layer 44 is provided on the outer side, it is possible to prevent the design from being deteriorated. Further, when the first dark color layer 44 and the second dark color layer 43 are provided, the heat generated in the heat generating conductor 40 is easily transmitted by radiation. According to the transfer of heat by radiation, a more uniform heating can be realized by avoiding that a part of the heat generating plate 10 is locally heated than the transfer by heat conduction. For this reason, it is possible to further reduce the peripheral region A1 that may be altered by heat. Since the light incident on the heating plate 10 is difficult to spread, the generation of distortion can be further suppressed. Further, according to the heat transfer by radiation, the first substrate 11 and the second substrate 12 can be efficiently heated, or snow, water droplets and the like attached to the surface of the heating plate 10 can be directly heated. That is, the function of the heat generating plate 10 can be exhibited more efficiently.

  In the heat generating conductor 40 shown in FIG. 4, the distance between the centers of gravity of two adjacent opening regions 47 is 100 μm or more and 10,000 μm or less, more preferably 7000 μm or less, and further preferably 5000 μm or less. It has become. In the heating conductor 40 shown in FIG. 5, the average length of the gap 49 along the direction non-parallel to the second direction d2 is 100 μm or more and 12000 μm or less, more preferably 7000 μm or less. More preferably, it is 3000 μm or less. In such a heat generating conductor 40, it is possible to suppress the occurrence of uneven heat generation while ensuring the transparency of the heat generating conductor 40. For this reason, it is possible to further reduce the peripheral region A1 that may be altered by heat. Since the light incident on the heating plate 10 is difficult to spread, the generation of distortion can be further suppressed.

  The sheet resistance of the heat generating conductor 40 is 0.1Ω / □ or more and 1Ω / □ or less, more preferably 0.2Ω / □ or more, and further preferably 0.3Ω / □ or more. It has become. In such a heat generating conductor 40, the heat generation amount in the heat generating conductor 40 is ensured, and the heat generation amount is too large, thereby causing uneven heat generation between the region near the linear conductor 41 and other regions. It is possible to suppress the occurrence. For this reason, it is possible to further reduce the peripheral region A1 that may be altered by heat. Since the light incident on the heating plate 10 is difficult to spread, the generation of distortion can be further suppressed.

  The ratio (T1 / H) of the thickness T1 of the first portion 31 of the bonding layer 30 to the height H of the linear conductor 41 is preferably 3 or more, and more preferably 4 or more. When the thickness T1 of the first portion 31 is sufficiently large with respect to the height of the linear conductor 41, the heat generating conductor 40 in the manufacturing process of the heat generating plate 10 becomes the first portion 31 (base film) of the bonding layer 30. When being embedded in 21), the heat generating conductor 40 is easily and completely embedded in the first portion 31. In other words, the heat generating conductor 40 is embedded in the first portion 31 without a gap. For this reason, it is possible to effectively suppress the entry of air or the like between the first substrate 11 and the bonding layer 30.

  Furthermore, the ratio (T2 / H) of the thickness T2 of the second portion 32 of the bonding layer 30 to the height H of the linear conductor 41 is preferably 20 or more, and more preferably 60 or more. When the thickness T2 of the second portion 32 is sufficiently large with respect to the height of the linear conductor 41, the heat generating conductor 40 in the manufacturing process of the heat generating plate 10 becomes the first portion 31 (base film) of the bonding layer 30. The deformation of the first portion 31 caused when the heat generating conductor 40 is embedded in the first portion 31 when embedded in 21) can be easily flattened by the second portion 32. In other words, it is possible to prevent a gap from being generated between the first portion 31 and the second portion 32. For this reason, it is possible to effectively suppress the entry of air or the like between the first portion 31 and the second portion 32 or between the second portion 32 and the second substrate 12.

  However, the ratio (T1 / H) of the thickness T1 of the first portion 31 of the bonding layer 30 to the height H of the linear conductor 41 is set so that the entire thickness of the heat generating plate 10 does not become too thick. 8 or less, more preferably 7 or less. For the same reason, the ratio (T2 / H) of the thickness T2 of the second portion 32 of the bonding layer 30 to the height H of the linear conductor 41 is preferably 130 or less, and preferably 110 or less. More preferred.

  Next, an example of a method for manufacturing the heating plate 10 will be described.

  First, as shown in FIG. 7, a dark film 43 a that forms the second dark layer 43 is provided on the base film 21 that forms a part of the bonding layer 30. The base film 21 has heat sealability. The dark color film 43a is provided in a state of being processed so as to be rough. Alternatively, the dark color film 43 a is processed so as to be rough after being provided on the base film 21. The dark color film 43a can be processed so as to be rough by, for example, immersing it in a mixed solution of a sodium chlorite aqueous solution and a sodium hydroxide aqueous solution. That is, the surface has a large surface roughness Sz.

  Next, a conductive film 42a for forming the conductive layer 42 is provided on the dark color film 43a. The conductive film 42a can be formed by a known method. For example, a method of attaching a metal foil such as a copper foil, a plating method including electroplating and electroless plating, a sputtering method, a CVD method, a PVD method, an ion plating method, or a method in which two or more of these are combined is adopted. can do. Alternatively, the conductive film 42a may be formed by applying a paste-like material containing a conductive metal or the like. Alternatively, two layers may be formed at the same time by attaching an electrolytic copper foil or a rolled copper foil made of the conductive film 42a provided with the dark color film 43a processed to be rough.

  Thereafter, as shown in FIG. 8, a resist pattern 50 is provided on the conductive film 42a. The resist pattern 50 has a shape corresponding to the arrangement pattern of the linear conductors 41 to be formed. The resist pattern 50 can be formed by patterning using a known photolithography technique.

  Next, the conductive film 42a and the dark color film 43a are etched using the resist pattern 50 as a mask. By this etching, the conductive film 42 a and the dark color film 43 a are patterned into a pattern substantially the same as the resist pattern 50. As a result, as shown in FIG. 9, a conductive layer 42 that forms part of the linear conductor 41 is formed from the patterned conductive film 42a. Further, a second dark color layer 43 that forms part of the linear conductor 41 is formed from the patterned dark color film 43a.

  Note that the etching method is not limited to wet etching using an etching solution, and a known method can be employed. As a known method, for example, plasma etching or the like may be used. After the etching process, the resist pattern 50 is removed as shown in FIG.

  Thereafter, as shown in FIG. 11, the first dark color layer 44 is formed on the surface and the side surface opposite to the surface on which the second dark color layer 43 of the conductive layer 42 is provided. The first dark color layer 44 is, for example, subjected to darkening treatment (blackening treatment) on a part of the material forming the conductive layer 42, and from the part forming the conductive layer 42, the first dark color layer 44 made of metal oxide or metal sulfide A dark color layer 44 can be formed. Further, the first dark color layer 44 may be provided on the surface of the conductive layer 42. Further, the first dark color layer 44 may be provided by roughening the surface of the conductive layer 42.

  The film 20 with a conductor which has the conductor 40 for a heat | fever and the base film 21 which supports the conductor 40 for a heat | fever is produced by the above process. The bus bar 45 of the heat generating conductor 40 may be formed integrally with the conductive layer 42 of the linear conductor 41 by patterning the conductive film 42a, or may be a wire provided on the base film 21. The conductor 41 may be a separate conductor.

  Finally, as shown in FIG. 12, the heat generating conductor 40 supported by the base film 21 is disposed between the first substrate 11 and the second substrate 12. Further, an adhesive film 22 is disposed between the first substrate 11 and the second substrate 12 and on the base film 21 side of the film with conductor 20. The adhesive film 22 has heat sealability. In this state, the first substrate 11 and the second substrate 12 are bonded to each other by pressing and heating. At this time, the heat generating conductor 40 is embedded in the base film 21 while being in contact with the first substrate 11. When the base film 21 and the adhesive film 22 are heated and pressed, the base film 21 becomes the first portion 31 of the bonding layer 30, and the adhesive film 22 becomes the second portion 32 of the bonding layer 30. In other words, the bonding layer 30 is formed by the base film 21 and the adhesive film 22. Through the above steps, the heat generating plate 10 shown in FIG. 3 is manufactured.

  In addition, as shown in FIG. 13, you may form the joining layer 30 only from the base film 21 by making the base film 21 provided with the dark color film | membrane 43a and the electrically conductive film 42a into sufficient thickness. In this case, as shown in FIG. 14, the heat-generating conductor 40 supported by the base film 21 is disposed between the first substrate 11 and the second substrate 12, and the first substrate 11 and the second substrate 12 are disposed. Join by pressing and heating toward each other. At this time, the heat generating conductor 40 is embedded in the base film 21 while being in contact with the first substrate 11. The side of the base film 21 on which the heat generating conductor 40 is provided is opposite to the side of the base film 21 on which the heat generating conductor 40 is provided in order to support the heat generating conductor 40. , Formed so as to have high hardness. In this case, the heat generating conductor 40 side of the base film 21 having a high hardness becomes the first portion 31 of the bonding layer 30 and is separated from the heat generating conductor 40 of the base film 21 having a low hardness. The side becomes the second portion 32 of the bonding layer 30. Even in such a process, the heat generating plate 10 shown in FIG. 3 is produced.

  As described above, the heat generating plate 10 of the present embodiment is disposed between the first substrate 11 and the second substrate that are spaced apart in the first direction d1, and the first substrate 11 and the second substrate 12. A heating conductor 40 that generates heat when a voltage is applied thereto, and a bonding layer 30 that bonds the first substrate 11 and the second substrate 12, and the heating conductor 40 is adjacent to the bonding layer 30. The heat generating conductor 40 has a surface in contact with the first substrate 11. According to such a heat generating plate 10, the heat generated in the heat generating conductor 40 can be efficiently transmitted to the first substrate 11. In other words, less heat is conducted to the bonding layer 30. For this reason, it is possible to reduce the peripheral area A1 that may be altered by heat. Therefore, it is possible to suppress the occurrence of distortion in the field of view through the heat generating plate 10 while the heat generating plate 10 is heated.

  In particular, in the heat generating plate 10 of the present embodiment, the surface roughness Sz on the side in contact with the first substrate 11 of the heat generating conductor 40 is 3.0 μm or less. According to such a heat generating plate 10, the heat generated in the heat generating conductor 40 can be efficiently transmitted to the first substrate 11. For this reason, more heat can be conducted to the first substrate 11, and the peripheral region A <b> 1 that can be altered by heat can be further reduced. Therefore, since the light incident on the heat generating plate 10 is difficult to spread, the generation of distortion can be further suppressed.

  Furthermore, the manufacturing method of the heat generating plate 10 of the present embodiment includes a step of providing the conductive film 42a on the base film 21 having heat sealability, a step of patterning the conductive film 42a, the first substrate 11 and the second substrate 11. A step of pressing and heating the first substrate 11 and the second substrate 12 toward each other in a state where the base film 21 is disposed between the substrates 12. According to such a method for manufacturing the heat generating plate 10, the conductive film 42a for forming the conductive layer 42 is formed on the base film 21 having heat sealability, and therefore, the heat generating plate 10 described above can be easily manufactured. Can do.

  Note that various modifications can be made to the above-described embodiment.

  In the above-described embodiment, the example in which the heat generating plate 10 is formed in a curved shape has been described. However, the present invention is not limited to this example, and the heat generating plate 10 may be formed in a flat plate shape.

  In the above-described embodiment, the linear conductor 41 has a rectangular cross section. That is, the linear conductor 41 has the same length in the cross section, and the opposite sides facing the first direction d1 are parallel. However, the linear conductor 41 is not limited to a rectangular shape, and may have a trapezoidal cross section, for example. Further, the linear conductor 41 may have different lengths opposite to each other in the first direction d1.

  For example, as shown in FIG. 15, the cross-sectional shape of the linear conductor 41 may be a trapezoidal shape that is a shorter side of two opposite sides that are parallel to the side in contact with the first substrate 11. Further, the linear conductor 41 may have different widths on opposite sides in the cross section along the first direction d1. In particular, the width of the linear conductor 41 along the direction orthogonal to the first direction d1 may be narrower at a position closest to the second substrate 12 than at a position in contact with the first substrate 11. Further, the width of the linear conductor 41 along the direction orthogonal to the first direction d1 may gradually decrease from the first substrate 11 side to the second substrate 12 side. In these cases, the legs in the cross section of the linear conductor 41, that is, the side surfaces of the linear conductor 41 are inclined with respect to the direction orthogonal to the first direction and face the second substrate 12 side. it can. For this reason, the heat transmitted by the radiation from the side surface of the linear conductor 41 is easily directed to the second substrate 12. That is, not only the first substrate 11 but also the second substrate 12 can appropriately generate heat. Note that the side surface of the linear conductor 41 is not limited to a straight line as in the example shown in FIG. 15 and may be a curved line in the cross section along the first direction d1.

  In particular, when the surface roughness Sz of the side surface of the linear conductor 41 is larger than 1.0 μm, the heating plate 10 is made uniform by avoiding local heating of the heating plate 10 by radiation from the side surface of the linear conductor 41. Heat can be transferred to the second substrate 12 while heating. In other words, the second substrate 12 can generate heat efficiently. Furthermore, when the side surface of the linear conductor 41 includes the first dark color layer 44, radiation from the side surface of the linear conductor 41 can be promoted. It is possible to efficiently transfer heat to the second substrate 12 while uniformly heating the heat generating plate 10 by effectively avoiding local heating of the heat generating plate 10 by radiation from the side surface of the linear conductor 41. it can. In other words, the second substrate 12 can generate heat more efficiently.

  In addition, as shown in FIG. 12 and FIG. 14, the heat generating conductor 40 supported by the base film 21 is disposed between the first substrate 11 and the second substrate 12, and the first substrate 11 and the second substrate 12. In the step of joining the two substrates 12 by pressing and heating them toward each other, the legs in the cross section of the linear conductor 41, that is, the side surfaces of the linear conductor 41 are inclined with respect to the direction orthogonal to the first direction d1. However, when facing the second substrate 12 side, when the heat generating conductor 40 is embedded in the base film 21, air is interposed between the first substrate 11 and the base film 21 and the heat generating conductor 40. And the like can be effectively suppressed. Therefore, it is possible to avoid deterioration of the field of view through the heat generating plate 10 due to bubbles. Moreover, it can suppress effectively that the joining layer 30 which contacted air oxidized and yellowed, and the conductor 40 for heat_generation | fever which contacted air oxidized, and electroconductivity falls.

  Alternatively, as shown in FIG. 16, the cross-sectional shape of the linear conductor 41 may be a trapezoidal shape that is the longer side of the two opposite sides that are parallel to the side in contact with the first substrate 11. In particular, the width along the direction orthogonal to the first direction d1 of the linear conductor 41 may be wider at a position closest to the second substrate 12 than at a position in contact with the first substrate 11. Further, the width of the linear conductor 41 along the direction orthogonal to the first direction d1 may gradually increase from the first substrate 11 side to the second substrate 12 side. In these cases, the legs in the cross section of the linear conductor 41, that is, the side surfaces of the linear conductor 41 are inclined with respect to the direction orthogonal to the first direction d1 and face the first substrate 11 side. it can. For this reason, the heat transmitted by radiation from the side surface of the linear conductor 41 is easily directed to the first substrate 11. That is, the first substrate 11 can generate heat efficiently. Note that the side surface of the linear conductor 41 is not limited to a straight line as in the example shown in FIG. 15 and may be a curved line in the cross section along the first direction d1.

  In particular, when the surface roughness Sz of the side surface of the linear conductor 41 is larger than 1.0 μm, the heating plate 10 is made uniform by avoiding local heating of the heating plate 10 by radiation from the side surface of the linear conductor 41. Heat can be efficiently transferred to the first substrate 11 while heating. In other words, the entire first substrate 11 can be efficiently heated. Furthermore, when the side surface of the linear conductor 41 includes the first dark color layer 44, radiation from the side surface of the linear conductor 41 can be promoted. It is possible to efficiently transfer heat to the first substrate 11 while uniformly heating the heat generating plate 10 by effectively avoiding local heating of the heat generating plate 10 by radiation from the side surface of the linear conductor 41. it can. In other words, the entire first substrate 11 can generate heat more efficiently.

  The linear conductor 41 having a tapered cross-sectional shape as described above, for example, makes the dark color film 43a forming the second dark color layer 43 less likely to be etched than the conductive film 42a forming the conductive layer 42. Alternatively, it can be formed by facilitating etching. That is, if the dark color film 43a is less likely to be etched than the conductive film 42a, the dissolution of the dark color film 43a is less likely to proceed than the conductive film 42a, and the etching of the conductive film 42a on the dark color film 43a side is less likely to proceed. For this reason, as shown in FIG. 15, the cross-sectional shape of the linear conductor 41 tapers toward the side in contact with the first substrate 11, typically the cross-sectional shape of the linear conductor 41 is the first. The side in contact with the substrate 11 has a trapezoidal shape that is the shorter side of two opposite sides that are parallel (substantially parallel). If the dark color film 43a is more easily etched than the conductive film 42a, the dissolution of the dark color film 43a proceeds from the conductive film 42a, and the conductive film 42a is also etched from the side of the dissolved dark color film 43a. For this reason, as shown in FIG. 16, the cross-sectional shape of the linear conductor 41 is a tapered shape that tapers toward the side in contact with the first substrate 11, typically the side in contact with the first substrate 11 is parallel ( It becomes a trapezoidal shape that is the longer side of the two opposite sides (substantially parallel).

  In the example of the method for manufacturing the heating plate 10 described above, the first dark color layer 44 may be provided as follows. First, after the conductive film 42a and the dark color film 43a are patterned in the same pattern as the resist pattern 50 by an etching process, the first dark color layer roughened on the side surface of the conductive layer 42 without removing the resist pattern 50. 44 is formed. Thereafter, the resist pattern 50 is removed, and another part of the first dark color layer 44 that is not roughened is formed on the surface of the conductive layer 42 opposite to the surface on which the second dark color layer 43 is provided.

  By providing the first dark color layer 44 in this way, the surface roughness Sz of the heat generating conductor 40 on the side in contact with the first substrate 11 can be easily reduced. That is, the surface roughness Sz on the side in contact with the first substrate 11 of the heat generating conductor 40 can be easily set to 3.0 μm or less.

  Alternatively, as shown in FIG. 17, in the linear conductor 41 of the heat generating conductor 40, the first dark color layer 44 may not be provided on the side in contact with the first substrate 11. That is, the first dark color layer 44 may be provided only on the side surface of the conductive layer 42. The first dark color layer 44 is formed on the side surface of the conductive layer 42 without removing the resist pattern 50 after the conductive film 42a and the dark color film 43a are patterned in the same pattern as the resist pattern 50 by an etching process. It can be provided by forming a part of the roughened first dark color layer 44.

  In such a heating conductor 40, the conductive layer 42 is exposed on the side in contact with the first substrate 11. The conductive layer 42 has a small surface roughness. Therefore, the surface roughness Sz of the heat generating conductor 40 on the side in contact with the first substrate 11 can be easily reduced. That is, the surface roughness Sz on the side in contact with the first substrate 11 of the heat generating conductor 40 can be easily set to 3.0 μm or less.

  The heat generating plate 10 may be used for a rear window, a side window, or a sunroof of the automobile 1. Moreover, you may use for the transparent part of windows or doors of moving bodies other than a motor vehicle, such as a railway vehicle, an aircraft, a ship, and a spacecraft.

  Furthermore, the heat generating plate 10 is not only a moving body, but particularly a place that divides the room and the outside, such as a building or a store, a house window or a transparent part of a door, a window or door of a building, a refrigerator, an exhibition box, a cupboard, etc. It can also be used for a transparent part of a window or door of a storage or storage facility.

  The heat generating plate 10 may be used as a defroster, or may be used as a defogger for the first substrate 11 and the second substrate 12. Or you may use as other uses, such as a heating appliance.

  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 Car 5 Front window 7 Power supply 10 Heat generating plate 11 1st board | substrate 12 2nd board | substrate 15 Wiring part 20 Film 21 with a conductor 21 Base film 22 Adhesive film 30 Joining layer 31 1st part 32 2nd part 40 Heating conductor 41 Linear conductor 42 Conductive layer 43 Second dark color layer 44 First dark color layer 45 Bus bar 46 Branch point 47 Opening region 48 Connection element 49 Gap

Claims (20)

A first substrate and a second substrate spaced apart in a first direction;
A heating conductor disposed between the first substrate and the second substrate and generating heat when a voltage is applied;
A bonding layer for bonding the first substrate and the second substrate;
The heating conductor is adjacent to the bonding layer;
The heat generating conductor is a heat generating plate having a surface in contact with the first substrate. A first substrate and a second substrate spaced apart in a first direction;
A heating conductor disposed between the first substrate and the second substrate and generating heat when a voltage is applied;
A bonding layer for bonding the first substrate and the second substrate;
The heating conductor is adjacent to the bonding layer;
The heating conductor is in contact with the first substrate;
The heat generating plate, wherein the surface roughness Sz of the heat-generating conductor on the side in contact with the first substrate is 3.0 μm or less.   3. The heat generating plate according to claim 1, wherein a surface roughness Sz of a surface adjacent to the bonding layer of the heat generating conductor is larger than 1.0 μm. The heating conductor includes a plurality of linear conductors,
The heating plate according to any one of claims 1 to 3, wherein the linear conductor includes a conductive layer and a dark color layer provided on at least a part of a surface of the conductive layer.   The heat generating plate according to claim 4, wherein the dark color layer is provided at least on a side of the linear conductor facing the first substrate.   The heat generating plate according to claim 4, wherein the dark color layer covers both sides of the surface of the conductive layer and a surface facing the second substrate. The heating conductor includes a plurality of linear conductors,
The line width of each linear conductor is 2 μm or more and 20 μm or less,
The heating plate according to any one of claims 1 to 6, wherein each linear conductor has a thickness of 1 µm or more and 30 µm or less. The heating conductor includes a plurality of linear conductors,
The heat generation according to any one of claims 1 to 7, wherein a ratio of a height of the linear conductor to a line width at each position of the linear conductor is 0.5 or more and 1.8 or less. Board. The heat generating conductor includes a plurality of linear conductors arranged in a pattern defining a plurality of opening regions,
The heat generating plate according to any one of claims 1 to 8, wherein an average distance between centers of gravity of the opening regions is 100 µm or more and 10,000 µm or less. The heating conductor includes a plurality of linear conductors extending in one direction and arranged with a gap in a direction non-parallel to the one direction,
The heating plate according to any one of claims 1 to 9, wherein an average length of the gap along a direction non-parallel to the one direction is not less than 100 µm and not more than 12000 µm.   The heating plate according to any one of claims 1 to 10, wherein a sheet resistance of the heat generating conductor is 0.1Ω / □ or more and 1Ω / □ or less. The heating conductor includes a plurality of linear conductors,
The bonding layer includes a first portion adjacent to the heat-generating conductor, and a second portion positioned away from the first portion in the first direction,
The heating plate according to any one of claims 1 to 11, wherein a ratio of a thickness of the first portion to a height of the linear conductor is 3 or more and 8 or less.   The heating plate according to claim 12, wherein a ratio of the thickness of the second portion to the height of the linear conductor is 20 or more and 130 or less. The heating conductor includes a plurality of linear conductors,
The heat generating plate according to claim 1, wherein a cross-sectional shape of the linear conductor is a trapezoidal shape.   The heat generating plate according to claim 14, wherein a cross-sectional shape of the linear conductor is a trapezoidal shape that is a shorter side of two opposite sides parallel to each other in contact with the first substrate.   The heat generating plate according to claim 14, wherein a cross-sectional shape of the linear conductor is a trapezoidal shape in which a side in contact with the first substrate is a longer side of two opposite sides parallel to each other. The heating conductor includes a plurality of linear conductors,
The heat generating plate according to any one of claims 1 to 14, wherein a cross-sectional shape of the linear conductor is narrower at a position closest to the second substrate than at a position in contact with the first substrate. The heating conductor includes a plurality of linear conductors,
The heat generating plate according to any one of claims 1 to 14, wherein a cross-sectional shape of the linear conductor is wider at a position closest to the second substrate than a position in contact with the first substrate. A film with a conductor used for a heating plate,
A heating conductor that generates heat when a voltage is applied;
A substrate film for supporting the heat-generating conductor,
The base film is a film with a conductor having heat sealing properties. Providing a conductive film on a base film having heat-sealability;
Patterning the conductive film;
A step of pressurizing and heating the first substrate and the second substrate toward each other in a state where the base film is disposed between the first substrate and the second substrate. Production method.

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