JPH06325860A - Structure of heating body - Google Patents

Abstract

PURPOSE:To provide a heating body structure using a PTC heater element, wherein it is capable of emitting heat only from the specified heat emission surface. CONSTITUTION:A heating body structure includes a PTC heater element 1, two electrodes 2, 3 affixed opposingly to the surface of this heater element 1, and a ceramic heat radiating member 4 having electric insulating property which is affixed to the surface of at least one 3 of these electrodes. The arrangement further includes a heat insulation member 7 surrounding the whole area, except the specified heat emission surface of the member 4, of those surfaces of heater element 1, electrodes 2, 3, and member 4 which are exposed to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating element structure using a PTC heater element.

[0002]

2. Description of the Related Art The present applicant has previously proposed a heating element structure using a PTC heater element by sticking two electrodes facing each other on the surface of the PTC heater element, and at least one of these two electrodes. Has proposed and applied for a patent in which a heat dissipation member made of ceramic having an insulating property is adhered to the surface of the electrode.

[0003]

However, in the structure of the heating element having such a structure, the heat is radiated also from a portion other than the predetermined heat radiating surface, resulting in poor efficiency. When used in a product, there have been problems such as overheating of electronic components in the vicinity of the product to cause a malfunction, or contact between the wiring and a heating element to melt the covering member of the wiring to cause a short circuit. The present invention has been made in view of the above circumstances, and an object thereof is to provide a heating element structure capable of radiating heat only from a predetermined heat radiating surface.

[0004]

In order to achieve the above-mentioned object, a heating element structure according to the present invention comprises a PTC heater element, and two electrodes attached to face the surface of the PTC heater element. A ceramic heat-dissipating member having an insulating property, which is adhered to the surface of at least one of these two electrodes, and the PTC heater element, the electrode, and the heat-dissipating member which are exposed to the outside of the heat-dissipating member. And a heat insulating member that surrounds the entire surface excluding a predetermined heat radiation surface.

Here, the PTC heater element means a heater element which has an automatic temperature control function and does not require a control system. By mixing a plurality of raw materials having different Curie points into one heating element, various heating elements can be obtained. The exothermic temperature of can be obtained.
Further, the heat dissipation member means a member made of ceramics such as Al ₂ O ₃ , Si ₃ N ₄ and AlN, having an insulating property and a high thermal conductivity.

Further, the heat insulating member has a heat resistant temperature of 300.
It refers to resin, ceramics (including ceramics) of about ° C. When a resin is used, the PTC heater element and the like are surrounded as follows. That is, a case-shaped resin is adhered or mechanically joined to a PTC heater element or the like with a heat-resistant adhesive so as to be integrated with them, or a liquid resin is molded at a necessary portion of the PTC heater element or the like. Let it harden. When ceramics is used, the PTC heater element and the like are surrounded as follows. That is, a case is molded using ceramics, and the case is bonded or mechanically bonded to a PTC heater element or the like with a heat-resistant adhesive to be integrated with the PTC heater element or the like. Since the ceramic used as the heat insulating layer must have low thermal conductivity, it is more preferably porous.

[0007]

With this structure, all the surfaces of the PTC heater element, the electrodes, and the heat radiation member that are exposed to the outside except the predetermined heat radiation surface of the heat radiation member are surrounded by the heat insulating member. The generated heat is radiated from only a predetermined position of the heat dissipation member.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to FIG. It has a plate shape and the size is 6m.
Screen printing Ag paste 2 as an electrode on the lower surface of the PTC heater element 1 (Curie temperature 120 ° C.) of m × 6 mm × 3 mm, and forming a plate shape on the upper surface of the PTC heater element 1 with a size of 10 mm. × 10 mm × 3 mm
A heat-dissipating member 4 made of alumina and having an Ag paste 3 as an electrode screen-printed on the lower surface thereof is attached such that the Ag paste 3 faces the Ag paste 2 and these are dried, and then the temperature is set to 600 ° C. in a heating furnace. Heat for 5 minutes at ° C. Then, the lead wires 5 and 6 are attached to the right ends of the two Ag pastes 2 and 3, respectively. A thermosetting resin 7 as a heat insulating member is molded on all the surfaces of the PTC heater element 1, the Ag pastes 2 and 3 and the heat radiating member 4 that are exposed to the outside except the upper surface of the heat radiating member 4, and then heat is applied. The curable resin 7 is heat-cured to surround the PTC heater element 1, Ag pastes 2, 3 and the like.

In the heating element structure thus manufactured, one AA
Electricity from the dry battery is supplied through the lead wires 5 and 6 and PT
The C heater element 1 was caused to generate heat, and the change with time of the temperature of the central portion of the upper surface of the heat dissipation member 4 at this time was measured. The measurement was performed using a K-type thermocouple and a recorder (LR8100 manufactured by Yokogawa Electric Co., Ltd.) under no wind. The measurement result is shown by a solid line in FIG.

[0010]

[Comparative Example] In order to see the effect of the heat insulating member, one of the heating element structures of the above-described embodiments is manufactured without a heat insulating member, and the heat radiating member 4 is heated under the same conditions and method as those of the embodiment. The temperature of the central part of the upper surface of was measured. The result is shown by a dashed line in FIG.

[0011]

As is apparent from the above description, according to the present invention, all the surfaces of the PTC heater element, the electrode and the heat radiation member exposed to the outside except the predetermined heat radiation surface of the heat radiation member are surrounded by the heat insulating member. Therefore, there is no useless heat dissipation from other than the specified heat radiation surface, so the efficiency is better than that of the conventional heating element, and when this heating element is used as a component in a specified electrical product, its surroundings The above-described adverse effects such as overheating of the electronic component and melting of the wiring covering member due to contact with the wiring to cause a short circuit are not produced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a comparative example for comparison with one embodiment of the present invention.

FIG. 3 is a graph showing the temperature measurement results of Examples and Comparative Examples of the present invention.

[Explanation of symbols]

 1 PTC heater element 2 3 Ag paste 4 Heat dissipation member 7 Thermal insulation member

Claims (1)

[Claims] 1. A PTC heater element, two electrodes adhered to the surface of the PTC heater element so as to face each other, and an insulating property adhered to the surface of at least one of the two electrodes. A heat dissipation member made of ceramics,
A heating element structure, comprising: a TC heater element; and a heat insulating member that surrounds all surfaces of the electrode and the heat radiating member that are exposed to the outside except a predetermined heat radiating surface of the heat radiating member.