JPS6347236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a heat-sensitive sheet heating element.

Conventionally, in electric heating devices such as electric carpets, negative temperature -
Temperature detection electrodes 2 are stretched on one side of a thermosensitive resin surface material 1 made of a polyamide-based material having impedance characteristics, and a heating line 3 is stretched on the other side.
Both sides of this thermosensitive resin surface material 1 are covered with insulating films 4, 4.
The temperature of the heat-sensitive sheet heating element 5 coated with is controlled by a temperature control circuit as shown in FIG. 3, for example, as follows.

That is, the heating line 3 of the heat-sensitive sheet heating element 5
A power supply 8 is connected to the power supply through the normally open contact 7a of the power supply relay 7, and the oscillation circuit 10 is operated with the output voltage V _D of the power supply circuit 9 that converts the power supply 8 into a constant voltage DC power supply. The high frequency voltage V outputted from the circuit is divided by a voltage dividing capacitor 11 and applied between the temperature detection electrode 2 and the heating line 3 of the heat-sensitive sheet heating element 5, so as to correspond to the impedance of the heat-sensitive sheet heating element 5. Filter circuit 12 for voltage signal
The detected value is inputted to the comparison circuit 14 that constitutes the front stage of the next stage switching circuit 13, and the reference voltage of this comparison circuit 14 is compared with the detected value, and the detected value is When the voltage falls below this reference voltage, this comparator circuit 14 inverts the transistor 15 constituting the latter stage of the switching circuit 13, which had been kept in the on state within the safe temperature range, to the off state, and connects the transistor 15 in series. The excitation coil of the power supply relay 7 stops driving, and the normally open contact 7a connected between the power source 8 and the heating line 3 is reversed from the on state to the off state, and the power supply to the heater circuit is stopped. It was designed to cut off the road.

However, in the structure of the heat-sensitive sheet heating element 5, if foreign matter 6 such as iron powder or carbon particles gets mixed into the layer during extrusion molding of the heat-sensitive resin face material 1, the thickness of the heat-sensitive resin face material 1 may change. is usually thin, about 40 to 100 μm, so this foreign object 6 causes a short circuit between the heat generating line 3 and the temperature detection electrode 2, as shown in FIG. This impedance does not indicate the impedance of the thermosensitive resin surface material 1, which poses a problem in that it impedes temperature control. In order to avoid such inconveniences, it is necessary to use a material with sufficient thickness as the thermosensitive resin facing material 1 in advance, so that even if foreign matter 6 is mixed into the layer of the thermosensitive resin facing material 1, the presence of the foreign matter 6 will cause heat generation. It is necessary to prevent a short circuit from occurring between the line 3 and the temperature detection electrode 2, but on the other hand, when this is applied to an electric carpet, etc., it is necessary to have appropriate flexibility. However, there is a limit to the method of increasing the thickness of the thermosensitive resin surface material 1 as described above, and there is a drawback that a large amount of material is required.

Therefore, a heat-sensitive sheet heating element has been proposed that can solve these problems. That is, the fifth
As shown in the figure and FIG. 6, this heat-sensitive heating element 5
A heating line 3' made of aluminum foil or the like is arranged on one side of a thermosensitive resin surface material 1' exhibiting negative temperature-impedance characteristics, and the heating line 3' is disposed on the same surface of this thermosensitive resin surface material 1'. Temperature detection electrodes 2' made of a conductive material such as aluminum foil are arranged in parallel with each other at a predetermined interval between the temperature sensing electrodes 2' made of a conductive material such as aluminum foil, while temperature detection electrodes 2' made of a conductive material such as aluminum foil are arranged in parallel over the entire other surface of the thermosensitive resin surface material 1'. A plurality of auxiliary conductive plates 16 made of a conductive material are spread out and stretched, and both surfaces of the thermosensitive resin surface material 1' are covered with insulating films 4', 4'.

However, when manufacturing a heat-sensitive sheet heating element with such a structure, as shown in FIG. The line 3', the temperature detection electrode 2', and the auxiliary conductive plate 16 on the other side are printed with resist ink 17, and then etched to form a pattern, and then an insulating film 4' is applied. Therefore, in the middle of the process in which both sides of the thermosensitive resin facing material 1' are etched, the strength of the thermosensitive resin facing material 1' alone becomes sufficient to hold the thermosensitive resin facing material 1'. As a result, during the process, especially during the etching process and the process of pasting the insulating film 4', elongation occurs due to insufficient strength of the material, resulting in poor dimensional stability.
Yields also deteriorated. Furthermore, in the heat-sensitive sheet heating element configured according to this proposed example, there is an advantage that the thickness of the heat-sensitive resin face material 1' and the auxiliary conductive plate 16 can be made thinner than that of the conventional configuration. The disadvantage was that the strength decreased significantly, making it impossible to implement.

Therefore, an object of the present invention is to avoid short circuits between the heat generating line and the temperature detection electrode due to contamination of foreign matter, to reduce the thickness of the thermosensitive resin material, and to avoid inhibiting flexibility as a sheet heating element. Another object of the present invention is to provide a method for manufacturing a heat-sensitive sheet heating element that can ensure dimensional stability, improve yield and finishing accuracy, and be inexpensive.

In the manufacturing method of the present invention, the heating line and temperature detection electrode to be arranged on one side of the thermosensitive resin material are first printed on one surface of an insulating film, and the auxiliary conductive plate to be arranged on the other side of the thermosensitive resin material is also formed separately. It is characterized in that it is printed on one surface of two insulating films, and a heat-sensitive resin material is interposed between these insulating films.

A first embodiment of this invention will be explained with reference to FIG. That is, a material is obtained by printing a heat generating line 3' and a temperature detection electrode 2' with resist ink on a metal foil made of aluminum foil or the like attached to an insulating film 4'', and then etching it to form a pattern, and removing the remaining resist ink. Between A ₁ and material B ₁ , which is made by printing the auxiliary conductive plate 16' with resist ink on a metal foil made of aluminum foil or the like, etching it to form a pattern, and removing the remaining resist ink, It is made by extrusion molding a thermosensitive resin material 1'' consisting of, etc. Note that the resist ink usually impedes the temperature-impedance characteristics and therefore needs to be removed. The removal method for this purpose is preferably carried out in the neutralization step that is usually carried out after etching. For example, when etching is carried out with an aqueous sodium hydroxide (NaOH) solution, it is usually neutralized with ferric chloride (FeCl ₃ ), but in this case, the properties of the resist ink must be alkali-resistant and acid-soluble. Good choice.
After that, there is usually a washing process, so materials A ₁ and B ₁ from which the resist ink has been removed can be easily produced.

A second embodiment of the invention will be explained with reference to FIG. That is, the heating line 3' and the temperature detection electrode 2' are coated with a resist ink 17'' that does not significantly affect the detection of the temperature-impedance characteristic of the thermosensitive resin material 1'' on a metal foil such as aluminum foil pasted on the insulating film 4''. The above-mentioned resist ink 17'' is applied to the material _A2 which is printed and then etched to form a pattern, and the metal foil also made of aluminum foil etc.
A thermosensitive resin material _1'' is extruded between the auxiliary conductive plate 16' printed and then etched to form a pattern, and a thermosensitive resin material 1'' is extruded. 12 contains an ion conductive additive, resist ink 17'' is made by dissolving a copolymer of nylon 6/66/12 in a solvent and mixing it with a silane coupling agent, and metal foil 2. ',3',17'
The method using aluminum foil showed good results.

A third embodiment of the invention will be explained with reference to FIG. That is, the heating line 3' and the temperature detection electrode are coated with resist ink 17'', which does not significantly affect the detection of the temperature-impedance characteristic of the thermosensitive resin material 1'', on a metal foil such as aluminum foil attached to the insulating film 4''. 2' is printed and then etched to form a pattern, and material B ₃ is made of an auxiliary conductive part 19 formed on an insulating film 4' with conductive ink 18 mixed with carbon _or metal powder. In between, a thermosensitive resin material 1'' is extruded. In addition, materials A ₁ -
A ₃ , B ₁ to B ₃ can be combined in various ways among the embodiments. Further, since each material is not limited to the materials in the embodiments, other materials may also be used.

Heat-sensitive sheet heating element 5'' manufactured in this way
As shown in FIG. 5, a power supply is applied between both terminals 3'a, 3'a of the heating line 3' facing the edge of the heat-sensitive resin surface material 1' to generate heat, and the heat-sensitive resin surface material 1' is also heated. By applying a high frequency voltage between the terminal 2'a of the temperature detecting electrode 2' facing the edge of the temperature detecting electrode 2' and the terminal 3'a of the heating line 3' using the circuit configuration shown in FIG. The impedance of the thermosensitive resin surface material 1' between both terminals 2'a and 3'a is detected, and temperature control is performed thereby. Note that each cross-sectional view in the figure is schematically enlarged in the vertical direction for easy understanding.

With this configuration, in the configuration of the planar heating element, due to the presence of the plurality of auxiliary conductive plates 16' distributed and stretched on one side of the thermosensitive resin surface material 1'', the heating line 3' and the temperature detection electrode 2' The voltage applied between the temperature detection electrode 2' and the auxiliary conductive plate 16 facing the temperature detection electrode 2',
The voltage is divided between the auxiliary conductive plate 16 and the heating line 3' facing the auxiliary conductive plate 16,
A partial voltage electric field path P as shown by the imaginary lines in FIG. 7 is provided over multiple regions, and in this partial voltage electric field path P, iron particles etc. Even if there is a short circuit between the heating line 3' and the auxiliary conductive plate 16 or between the temperature detection electrode 2' and the auxiliary conductive plate 16 due to foreign matter 6,
There is no short circuit between the heating line 3' and the temperature detection electrode 2', and even if a plurality of foreign substances 6 are mixed in, the auxiliary conductive plates 16 are arranged in a distributed manner. As shown in FIG. 7, there is a very low probability that foreign matter 6 will enter between the heating line 3' and the auxiliary conductive plate 16 and between the auxiliary conductive plate 16 and the temperature detection electrode 2' at the same time, so the occurrence of the short circuit can be greatly suppressed. For this purpose, heat-sensitive resin surface material 1'
There is no need to increase the thickness, and flexibility is not inhibited.

Further, as shown in FIG. 11a, if the thickness of the thermosensitive resin surface material 1' is t, then the partial voltage electric field path P applied between the heating line 3' and the temperature detection electrode 2'
, an impedance equivalent to that obtained by interposing the heat-sensitive resin face material 1' with a thickness of 2t is given, and in order to give the same impedance in the conventional structure shown in FIG. 11b, the thickness is While it is necessary to use a heat-sensitive resin face material 1 of 2t, in this embodiment, a heat-sensitive resin face material 1' with half the thickness is used.
In this way, sufficient impedance can be provided between the heat generating line 3' and the temperature detection electrode 2' without affecting temperature detection accuracy.

Furthermore, as the heat generating line 3' is heated, the impedance of the area near the heat generating line 3' of the thermosensitive resin surface material 1' decreases before that of other areas; Since the structure in which the heating line 3 and the temperature detection electrode 2 are arranged opposite to each other in the thickness direction of the thermosensitive resin surface material 1 by sandwiching the thermosensitive resin surface material 1 as shown in FIG. Impedance does not change sufficiently in the area near the temperature detection electrode 2', and temperature control is performed in response to a local temperature rise before the temperature of the entire area of the thermosensitive resin surface material 1' has risen sufficiently. Uniform temperature control can be performed over the entire area without causing any turbulence.

Moreover, since the heat generating line 3' and the temperature detecting electrode 2' are arranged side by side on the same surface of the thermosensitive resin surface material 1', the heat generating line 3' and the temperature detecting electrode 2' are formed by an etching process. In this case, the area of the conductive surface material such as aluminum foil to be dissolved away is reduced accordingly, the etching process can be carried out in a short time, and the utilization efficiency of the conductive surface material is improved.

By dispersing the heating line 3' and the temperature detection electrode 2' which are arranged in parallel densely on the surface of the thermosensitive resin surface material 1', they act as a reinforcing material for the thermosensitive heating element. It is also possible to improve the strength.

Furthermore, since there is no need to take a lead wire from the auxiliary conductive material 16' and the current flowing through the auxiliary conductive plate 16' is only a minute control current, it is recommended to use a metal foil such as aluminum foil for the auxiliary conductive material 16'. When using , the thickness can be made sufficiently thin.

On the other hand, according to the manufacturing method of this embodiment, a planar heating element having the above-mentioned effects can be obtained stably and with high precision. That is, the thermosensitive resin material 1'' is connected to the heating line 3', the temperature detection electrode 2' and the auxiliary conductive plate 16'.
are formed on the insulating film 4'' and then bonded in the middle, so the heating line 3', the temperature detection electrode 2' and the auxiliary conductive plate 16' are manufactured using the insulating film 4'' as a base material, and are reinforced with the strength of the insulating film. As a result, there is less elongation and shrinkage, resulting in improved dimensional stability and yield. Further, since there is no process in which the thermosensitive resin material 1'' requires its own strength, it can be made thinner, and the flexibility of the electric heating carpet is not inhibited.

As described above, in the method for manufacturing a heat-sensitive sheet heating element of the present invention, the heat-generating line and temperature detection electrode to be disposed on one side of the thermosensitive resin material are first formed on an insulating film, and then the heat generating line and the temperature detection electrode are disposed on the other side of the thermosensitive resin material. The auxiliary conductive plate to be installed was also formed on a separate insulating film, and a thermosensitive resin material was interposed between the insulating films. It is possible to form distributed electric field paths via auxiliary conductive materials in a distributed manner, thereby avoiding short circuits between the heat generating line and the temperature detecting electrode due to the contamination of foreign matter, as well as preventing short circuits between the heat generating line and the temperature detecting electrode. The impedance of the thermosensitive resin material can also be set sufficiently large, and highly accurate temperature control can be performed without impeding flexibility. In addition, since the insulating film is used as the base material for forming heating lines, etc., dimensional stability and yield can be improved, and since no force is applied to the thermosensitive resin material, the thickness of the thermosensitive resin material can be adjusted to the minimum required in terms of impedance characteristics. Furthermore, when using metal foil, the thickness of the auxiliary conductive material can be made thinner than before, and it is also possible to replace it with conductive ink, etc., which has less strength, resulting in a reduction in materials. It is expected to be highly effective and can be done at low cost.

[Brief explanation of drawings]

1 and 2 are respectively a perspective view and a sectional view of a conventional example, FIG. 3 is a temperature control circuit diagram of a heat-sensitive heating element of the conventional example, FIG. 4 is an explanatory diagram showing the drawbacks of the conventional example, and FIG. 6 and 6 are a partially cutaway plan view and a cross-sectional view showing the proposed example, respectively, FIG. 7 is a cross-sectional view with foreign matter mixed in, and FIG. 8 is a cross-sectional view of the first embodiment of the present invention. 9 is a sectional view of the embodiment shown in FIG. 2, FIG. 10 is a sectional view of the embodiment shown in FIG. 3, and FIG. 11 is a comparative diagram for explaining the operation. 1″...Thermosensitive resin material, 2′...Temperature detection electrode, 3′...
Heat generating line, 4'...insulating film, 16'...auxiliary conductive plate.

Claims (1)

[Claims] 1. A first step of forming heating lines and temperature detection electrodes in a predetermined pattern at predetermined intervals on the same surface of an insulating film, and forming auxiliary conductive plates in a predetermined pattern on another insulating film. a second step of forming;
A method for manufacturing a heat-sensitive sheet heating element, comprising a third step of placing the patterns of the insulating films produced in the first and second steps facing each other and interposing a heat-sensitive resin material therebetween. 2. The heating line, temperature sensing electrode, or auxiliary conductive plate is formed by printing a pattern with resist ink on a metal foil attached to the insulating film and etching it. How the body is manufactured. 3. The method of manufacturing a heat-sensitive sheet heating element according to claim 1, wherein the resist ink uses a material that does not affect the temperature impedance characteristics of the heat-sensitive resin material. 4. The method of manufacturing a heat-sensitive sheet heating element according to claim 1, wherein the auxiliary conductive plate is formed using conductive ink mixed with carbon or metal powder.