JP2004265654A - Sheet heater and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet heater that is thin, highly flexible, easy to manufacture, and uniform in heat distribution. <P>SOLUTION: The sheet heater comprises: a heater element 2 made of a patterned conductor film and laminated with heat-resistant insulating films 1 and 7; and a heat uniformizing film 8 made of a film of good thermal conductivity and formed over the surface of at least one of the insulating films 1 and 7. The sheet heater is manufactured through the steps of: forming the patterned heater element 2 on the insulating film 1; forming the other heat-resistant insulating film 7 on the heater element 2 to laminate the heater element 2; and forming the heat uniforming film 8 made of the film of good thermal conduction uniformly over the surface of at least one of the insulating films 1 and 7. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sheet heater having a sheet shape and having flexibility and a method for manufacturing the same, and more particularly to a sheet heater having substantially uniform heat distribution and easy to manufacture, and a method for manufacturing the same.
[0002]
[Prior art]
Conventionally, a flexible sheet-like heater that is used by being wound around the outer periphery of a heater pipe or a chemical reactor has a structure including a flexible heating element and a flexible electric insulating layer surrounding the heating element. is there. The required flexibility varies depending on the application, but a heater for heating the pipe is required to have a characteristic capable of bending along a curved surface.
[0003]
Conventionally, a flexible heater has a flexible heating element made of a nickel-chromium alloy, a nickel-chromium-iron alloy, a nickel-chromium-iron-manganese alloy, a platinum-rhodium alloy, or a paste of these alloys. It consisted of being covered with an electric insulating layer.
[0004]
[Problems to be solved by the invention]
However, the flexibility of the heat-resistant material used as the material of the electric insulating layer is generally small, and therefore, a sufficiently satisfactory flexibility cannot be obtained as the whole heater. Therefore, in order to obtain sufficient flexibility, a material having low heat resistance must be used, and there is a problem that the material cannot be used as a high-temperature heater.
[0005]
Further, the conventional sheet-shaped heater has a problem that it takes time and effort to manufacture the heater. For example, a conventional sheet-shaped heater is manufactured by bonding an insulating resin layer to a heating element by means of bonding using an adhesive, or by heating and pressing. However, in this method, it takes time to complete the lamination, and when the lamination is incomplete, the lamination surface may be peeled off.
[0006]
In addition, since the thermal conductivity of the insulating resin layer is small, there is a large difference in the amount of heat released between the heating element and the portion between the heating elements, causing a problem in that the temperature distribution becomes uneven. By reducing the distance between the heating elements, the unevenness of the temperature distribution can be eliminated to some extent. However, since the withstand voltage is low in the plane direction of the insulating resin layer, which is the interval direction between the heating elements, when the interval between the heating elements is reduced, the withstand voltage deteriorates and the desired heat generation characteristics cannot be obtained. .
An object of the present invention is to provide a sheet heater which is thin, has excellent flexibility, is easy to manufacture, and has a uniform heat generation distribution in view of the above-mentioned problems in the conventional sheet heater.
[0007]
[Means for Solving the Problems]
In the present invention, in order to achieve the above object, a conductor film is patterned into a heater element 2, which is laminated with heat-resistant insulating films 1 and 7 such as a polyimide resin to form a thin film-shaped sheet heater. The thickness of the seat heater was reduced. Further, a heat equalizing film 8 having good heat conduction such as stainless steel is formed on at least one surface of the heat-resistant insulating films 1 and 7 so that heat transmitted through the insulating film 7 is uniformly dispersed.
[0008]
Such a sheet heater performs patterning by etching the conductor film 10 for a laminate of the one insulating film 1 or 7 and the conductor film 10, or forming a patterning mask on the one insulating film 1 or 7. It can be manufactured by forming a heater element 2 made of a patterned conductive film by vacuum deposition or printing by using the same, and then forming the other insulating film 7 or 1 or the soaking film 8.
[0009]
That is, in the sheet heater according to the present invention, the heater element 2 composed of the patterned conductor film is laminated with the insulating films 1 and 7 having heat resistance, and the heat conduction is good on the surface of at least one of the insulating films 1 and 7. It is characterized in that a soaking film 8 made of a natural film is formed.
[0010]
Further, a method for manufacturing such a sheet heater includes a step of forming a patterned heater element 2 on a heat-resistant insulating film 1 and a step of forming another heat-resistant insulating film 7 on the heater element 2. And a step of laminating the heater element 2 and forming a uniform heat equalizing film 8 made of a film having good heat conductivity on the surface of at least one of the insulating films 1 and 7. Method. For example, the heater element 2 is formed by patterning by etching the conductor film 10 uniformly formed on the insulating film 1 having heat resistance.
[0011]
Such a sheet heater is constituted by only a heater element 2 made of a patterned conductive film and insulating films 1, 7 and a heat equalizing film 8 having heat resistance, so to speak, so that it can be made thinner. Therefore, it is excellent in flexibility.
Further, since the heat equalizing film 8 is formed on the surfaces of the insulating films 1 and 7, heat generated in the heater element 2 is transmitted to the heat equalizing film 8 through the thin insulating films 1 and 7. Since the heat equalizing film 8 is made of a film having good heat conductivity, heat is dispersed on one surface thereof, and the heat distribution becomes uniform. The insulating film 7 generally has a higher withstand voltage with respect to a current flowing in the thickness direction than in the plane direction.
[0012]
Further, this sheet heater can be manufactured only by a film forming step and patterning. For this reason, manufacture is easy, and a planar heater having a relatively large area can be manufactured.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described specifically and in detail with reference to the drawings.
FIG. 1 shows an embodiment of a seat heater according to the present invention, in which a part of a film is partially cut away.
[0014]
A heater element 2 made of a conductor film having a thickness of about 50 μm is formed on an insulating film 1 having a thickness of about 50 μm made of a heat-resistant resin such as a polyimide resin. In the illustrated example, the insulating film 1 is basically rectangular, and a protrusion serving as the terminal portion 11 protrudes from one short side thereof. The heater element 2 is patterned so as to form a continuous long conductor band on the insulating film 1, and terminal conductor portions 3 a and 3 b at both ends thereof are led out to the terminal portion 11 of the insulating film 1. Lead wires 4a and 4b are connected to the terminal conductors 3a and 3b by connection terminals 5a and 5b, and the heater element 2 is connected to a power supply by the lead wires 4a and 4b.
[0015]
Further, on the heater element 2, an insulating film 7 having a thickness of about 25 μm made of a heat-resistant resin such as a polyimide resin is formed over the entire surface of the insulating film 1 thereunder. On the insulating film 7, a soaking film 8 made of a stainless film having a thickness of about 50 μm is formed over the entire surface. The heat equalizing film 8 is preferably formed except for the terminal portion 11, that is, only on the rectangular portion of the main body of the insulating film 7. On the heat equalizing film 8, temperature measuring contacts of thermocouples 9a and 9b for temperature measurement are attached. In the illustrated example, the temperature measuring contacts of the two thermocouples 9a and 9b are mounted on the soaking film 8, one for monitoring and the other for temperature control. The thickness of the entire seat heater is about 200 μm.
[0016]
The heat-resistant temperature of the insulating films 1 and 7 made of a polyimide resin is about 300 ° C. The withstand voltage of the insulating film 7 made of the polyimide resin is higher for a current flowing in the thickness direction than for a current flowing in the surface direction. The withstand voltage with respect to the current flowing in the thickness direction is about 100 V / μm per unit thickness. In the case of the insulating film 7 having a thickness of 25 μm, a withstand voltage of about 2500 V can be obtained.
[0017]
The thermal conductivity of the heat equalizing film 8 is 0.2 W / m ° K, and the heat transmitted from the heater element 2 to the heat equalizing plate 8 through the thin insulating film 7 is thermally conducted over the entire surface of the heat equalizing film 8. Heat is dissipated. For this reason, even if the pattern interval of the heater element 3 is wide enough to obtain the above-mentioned withstand voltage of about 2500 V, a uniform temperature distribution can be formed.
[0018]
FIG. 2 is a cross-sectional view showing an example of a method for manufacturing the above-described seat heater, from semi-finished to completed sheet heaters.
First, as shown in FIG. 2A, a thin sheet having a two-layer structure including a heat-resistant insulating film 1 made of a polyimide resin or the like and a conductor film 10 such as a stainless steel film is prepared. This sheet is formed, for example, by applying a resin material on the conductive film 10 held on a flat stage and curing the resin material to form the insulating film 1, or by forming the insulating film 1 on the conductive film 10. Can be made by means of thermocompression bonding.
[0019]
Next, this sheet is arranged so that the conductive film 10 is on the upper side, a mask for patterning is formed on the conductive film 10 by exposing and developing a photoresist solution, and the conductive film 10 is patterned by chemical etching. The heater element 2 is formed as shown in FIG. The sheet is washed, the mask material and the etchant are dropped, and then the sheet is dried. Thereafter, the connection of the lead wires 4a and 4b shown in FIG. 1 is performed.
[0020]
Next, as shown in FIG. 2C, a heat-resistant insulating film 7 made of a polyimide resin or the like is provided on the heater element 2. The insulating film 7 is formed by applying a resin material onto a sheet held on a flat stage with the conductive film 10 facing upward and curing the resin material, or by applying the insulating film 7 on the heater element 2. It can be provided by means of thermocompression bonding.
The lead wires 4a and 4b can be connected after the insulating film 7 is applied. At this time, the insulating film 7 corresponding to the lead wire joining portion is formed with a hole or is processed later to form a hole.
[0021]
Next, as shown in FIG. 2D, a heat equalizing film 8 having good thermal conductivity such as stainless steel is provided on the insulating film 7. The heat equalizing film 8 can be provided, for example, by means of placing a stainless steel foil on the insulating film 7 and performing thermocompression bonding.
Finally, the thermocouples 9a and 9b shown in FIG. 1 are connected to appropriate positions on the heat equalizing film 8, and the seat heater is completed.
[0022]
FIG. 3 is a cross-sectional view showing another example of a method of manufacturing the above-described seat heater, from semi-finished to completed.
First, as shown in FIG. 3A, a sheet having a three-layer structure in which a heat-resistant resin film made of a polyimide resin or the like is laminated from both sides with a metal film such as a stainless steel film is prepared. The method of manufacturing this sheet is basically the same as the method of manufacturing a sheet having a two-layer structure described above with reference to FIG. 2A, and is manufactured by applying and drying a resin, thermocompression bonding of a metal film or a resin film, or the like. Can be done.
[0023]
In the sheet having the three-layer structure, the intermediate resin film serves as the insulating film 7 and the metal film on one side serves as the heat equalizing film 8.
Next, this sheet is arranged so that the conductor film 10 on the opposite side of the heat equalizing film 8 faces upward. After forming a mask in the same manner as described above, the conductor film 10 is patterned by chemical etching. The heater element 2 is formed as shown in FIG. The sheet is washed, the mask material and the etchant are dropped, and then the sheet is dried. Thereafter, the connection of the lead wires 4a and 4b shown in FIG. 1 is performed.
[0024]
Next, as shown in FIG. 3C, a heat-resistant insulating film 1 made of a polyimide resin or the like is provided on the heater element 2. The insulating film 1 is formed by applying a resin material on a sheet held on a flat stage with the conductive film 10 facing upward and curing the resin material, or by applying the insulating film 1 on the heater element 2. It can be provided by means of thermocompression bonding.
The lead wires 4a and 4b can be connected after the insulating film 1 is applied. In this case, the insulating film 1 corresponding to the lead wire joining portion is formed with a hole or is processed later to form the hole.
Finally, the thermocouples 9a and 9b shown in FIG. 1 are connected to appropriate positions on the heat equalizing film 8, and the seat heater is completed.
[0025]
FIG. 4 is a cross-sectional view from a semi-finished state to a completed state of a seat heater, showing still another example of the method for manufacturing the seat heater.
First, as shown in FIG. 4A, a metal paste such as silver or copper is screen-printed on a heat-resistant insulating film 1 made of a polyimide resin or the like, which is baked at a temperature of about 300 ° C. to form a pattern. The formed heater element 2 is formed. When a particularly thin heater element 2 is formed, a patterned conductive film 2 may be formed by vacuum-depositing a metal film using a mask plate. Thereafter, the connection of the lead wires 4a and 4b shown in FIG. 1 is performed.
[0026]
Next, as shown in FIG. 4B, a heat-resistant insulating film 7 made of a polyimide resin or the like is provided on the heater element 2. The insulating film 7 is formed by applying a resin material onto a sheet held on a flat stage with the conductive film 10 facing upward and curing the resin material, or by applying the insulating film 7 on the heater element 2. It can be provided by means of thermocompression bonding.
The lead wires 4a and 4b can be connected after the insulating film 7 is applied. At this time, the insulating film 7 corresponding to the lead wire joining portion is formed with a hole or is processed later to form a hole.
[0027]
Next, as shown in FIG. 4C, a heat equalizing film 8 having good thermal conductivity such as stainless steel is provided on the insulating film 7. The heat equalizing film 8 can be provided, for example, by means of placing a stainless steel foil on the insulating film 7 and performing thermocompression bonding.
Finally, the thermocouples 9a and 9b shown in FIG. 1 are connected to appropriate positions on the heat equalizing film 8, and the seat heater is completed.
[0028]
【The invention's effect】
As described above, since the seat heater according to the present invention is constituted only by the film, the seat heater can be made thin and excellent in flexibility. Further, the heat generated in the heater element 2 is transmitted to the heat equalizing film 8 through the thin insulating film 7, and the heat is dispersed all over the heat equalizing film 8, so that a uniform heat distribution can be obtained.
Further, the manufacturing method of the seat heater according to the present invention can be manufactured only by the film forming step and the patterning. For this reason, manufacture is easy, and a planar heater having a relatively large area can be manufactured.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a seat heater according to the present invention with a part of a film partially cut away.
FIG. 2 is a cross-sectional view from a semi-finished state to a completed state of the seat heater, showing one embodiment of a method for manufacturing the seat heater according to the present invention.
FIG. 3 is a cross-sectional view from a semi-finished state to a completed state of a seat heater showing another embodiment of the method for manufacturing a seat heater according to the present invention.
FIG. 4 is a cross-sectional view from a semi-finished state to a completed state of a seat heater showing still another embodiment of the method for manufacturing a seat heater according to the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 insulating film 2 heater element 7 insulating film 8 soaking film

Claims (3)

A sheet heater having a sheet shape and having flexibility, wherein a heater element (2) made of a patterned conductor film is laminated with heat-resistant insulating films (1) and (7), A seat heater characterized in that a heat equalizing film (8) made of a film having good heat conductivity is formed on the surface of one of the insulating films (1) and (7). A method for producing a sheet heater having a sheet shape and having flexibility, comprising: forming a patterned heater element (2) on a heat-resistant insulating film (1); A step of forming another heat-resistant insulating film (7) on the (2) and laminating the heater element (2); and a step of heat conduction on at least one of the insulating films (1) and (7). Forming a uniform soaking film (8) made of a good film. The step of forming a heater element (2) is a patterning step by etching a conductor film (10) uniformly formed on an insulating film (1) having heat resistance. 3. The method for manufacturing a seat heater according to item 2.

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