KR20020088908A - Surface type heating body by conductive material - Google Patents

Abstract

PURPOSE: A surface type heater is provided to reduce manufacturing procedures and reduce defects, while preventing life shortening or abnormal overheating caused due to the chemical change of an adhesive. CONSTITUTION: An electrode(1) is disposed on a thin and flat electric insulator(3), and a conductive material(2) is interposed between the electrode and the thin and flat electric insulator. The conductive material is heated when the electrode is electrified. The conductive material is deposited onto the flat electric insulator first, and then a conductive paste is deposited or a metal material is deposited/etched onto the conductive material. An adhesive(4) is deposited onto the electrode protruded from the flat electric insulator. Since the conductive material is deposited widely all over the electric insulator first, and the electrode is formed on the resultant structure, thus eliminating the necessity of checking the relative position during deposition of the conductive material.

Description

Surface heating element using a conductive material {Surface type heating body by conductive material}

The present invention relates to a planar heating element using a conductive material, and more particularly, by applying a conductive material on a substrate, which is an electrical insulator, drying the electrode and then placing an electrode thereon, thereby simplifying the manufacturing process and generating a low defect rate. It relates to a planar heating element using a conductive material.

In general, materials increase in resistance as temperature increases, but a material having a large change in resistance in a specific temperature range is called a PTC (Positive Temperature Coefficient) material. The PTC material is used as an electric element or a heater to protect overheating and overcurrent by using these characteristics. The material is mainly ceramic, but recently, polymers are used to diversify the range of use.

In the case of the polymer PTC material, when the ambient temperature rises or the temperature rises due to self-heating, the resistance gradually increases and then the resistance rapidly increases in a certain region.

When using PTC material as a device using the above characteristics, when current below a certain current is applied, Joule heat generated from PTC material and heat emitted to the outside are balanced, and PTC material serves as a general fixed resistor. However, when an overcurrent of a specific current or more is introduced into the circuit from outside and flows to the PTC device, such thermal balance is broken, and the PTC device's resistance increases with the PTC device's temperature due to self-heating of the PTC device. Flowing overcurrent is blocked so that circuits or components can be protected. On the other hand, if the cause of the overcurrent is removed, the resistance becomes low again, and the circuit operates normally.

If PTC material is used as a heater by using the above characteristics, it can be heated in a short time by flowing a lot of current with low resistance at low temperature, and if the temperature rises to a certain degree, the resistance rises rapidly in a specific temperature range and is determined as a heater. The main heat of heat supplied to the heater in the vicinity and the heat emitted to the outside are in equilibrium to achieve a constant temperature state.

The other characteristic of PTC element is that when it is used as a heater, the power of home or vehicle is mostly used. Therefore, excessive resistance change may cause overcurrent at low temperature, causing capacity overrun.

According to the experimental results of the inventors, when used as a thermal insulation heater, the resistance of about 30-50% is reduced at a low temperature of about -40 degrees below zero below 20 degrees Celsius as a reference resistance. At about 70 degrees Celsius, it is appropriate to suppress the increase in temperature by its own current by increasing the resistance of about 1000%.

Polymer PTC thermistor devices are widely used for temperature sensors, circuit protection, color TV devices (degaussing), constant temperature heating elements, motor starters, etc. in various forms such as disk, square plate, ring, rod, and small chip types.

Polymer PTC heater is a film-type planar heating element that generates heat by resistive heat from conductive material when it is energized. It is widely applied to all things that can be used.

Figure 3 is a cross-sectional view showing a planar heating element using a conventional conductive material, as seen here, a thin and flat electrical insulator (3), and bonded to the upper surface of the surface treatment (including silver plating, aluminum plating or etching treatment) The electrode 1, the electric insulator 3 and the conductive material 2 made of a material such as PTCR, and the conductive material to be attached to the back surface of the object to be heated. It consists of an adhesive 4 which is applied on top of the substance 2.

Here, the adhesive agent 4 is made of an insulating material such as an acrylic component, and is used for bonding to the rear surface of the object to be heated such as a rearview mirror.

On the other hand, in the conventional structure described above, the electrode 1 is formed by first applying a conductive paste to the electrical insulator 3 or by applying / etching a metal material, and then applying the conductive material 2 by the PTCR material. When the conductive material (2) is applied to the circuit, that is, the electrode (1) is applied to the thickness of the electrode circuit according to the thickness of the conductive material (2) is likely to occur, the conductive material (2) There is a problem that the temperature distribution is non-uniform because the performance is not formed uniformly.

In the conventional manufacturing process, since a circuit is first formed on the electric insulator 3, and then a PTCR material, that is, a conductive material 2 is applied to the circuit, the electrode 1 is applied on the electric insulator 3. In addition, even when applying the conductive material (2) to be consistently applied in accordance with the relative position, not only need to pay attention in the work industry, there was a big problem that the defective rate may occur.

In addition, in the conventional structure, since the adhesive 4 is in contact with the conductive material 2, that is, the heating element, the adhesive 4 may cause a chemical change when high heat occurs in the conductive material 2, thereby causing the adhesive ( There is a problem that the life of 4) is shortened and abnormal heat generation occurs.

In addition, in the conventional manufacturing process, the electrode 1 is coated on the electrical insulator 3, and then, through the first to second drying processes, an appropriate resistance of the electrode circuit is ensured, and a PTCR material, that is, a conductive material (2) is applied thereon. ) And then repeat the 1st and 2nd drying process, requiring a total of 4 or more drying processes. As such, it has to go through a lot of drying process, it takes a long time to complete the product, there was a problem that the manufacturing cost is also increased.

On the other hand, in order to increase the heating characteristics, it is preferable to apply a PTCR material, that is, a conductive material in multiple, in the conventional structure, after applying the electrode 1, the primary conductive material should be applied, and the secondary conductive material should be applied immediately thereon.

Various methods may be used as a coating method. However, in the case of using a silkscreen printing method, which is commonly used, a coating solution containing a solvent when applying a secondary conductive material on the surface of the primary conductive material may be used as a tool such as squeeze. Since it is necessary to scrape on the surface of the primary conductive material using, since the surface of the primary conductive material is likely to be partially melted or partially damaged, there is a high possibility that the coated surface may be uneven or aggregated. Therefore, there was a problem in that the heat generation performance is non-uniform.

The present invention has been made to solve the conventional problems as described above, by applying a conductive material on the substrate which is an electrical insulator and drying the electrode first placed thereon, so that the manufacturing process is simplified and less defective rate is generated. do.

In other words, in the past, the electrodes were first placed on the substrate, which is an electrical insulator, and the conductive materials had to be disposed thereon. Therefore, in the present invention, the PTCR material, that is, the conductive material, was first widened on the electrical insulator. Since it is necessary to form an electrode thereon, at least when applying a conductive material, there is no need to check the relative position one by one to make the manufacturing process much simpler.

In addition, the adhesive is not directly adjacent to the conductive material, which is a heating element, so as to be adjacent to each other, so that the adhesive is not excessively heated during use, so that life shortening or abnormal heating due to chemical change of the adhesive does not occur.

In addition, even when the conductive material is made of a double-bonded structure, the first and second conductive materials are not directly bonded, but are bonded with the electrodes interposed therebetween, so that the second conductive material is silk-screen printed by using a squeeze on the first conductive material. Even if it does not damage the surface of the primary conductive material at all, it is possible to more uniformly form the heat generating characteristics of the conductive material.

1 is a cross-sectional view showing a first embodiment of a planar heating element according to the present invention;

2 is a cross-sectional view showing a second embodiment of the planar heating element according to the present invention;

3 is a cross-sectional view of a planar heating element according to the prior art.

* Description of the symbols for the main parts of the drawings *

1 electrode 2,2 'conductive material

3: electrical insulator 4: adhesive

The configuration of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a first embodiment of a planar heating element according to the present invention, Figure 2 is a cross-sectional view showing a second embodiment of the planar heating element according to the present invention,

An electrode 1 is disposed above the thin and flat electrical insulator 3, and a conductive material 2 such as PTCR is disposed between the electrodes 1 so that the conductive material 2 generates heat when the electrode 1 is energized. In the planar heating element using a conductive material configured to

The conductive material 2 is first applied on the electrical insulator 3, and the electrode 1 is formed by applying a conductive paste on the upper surface of the conductive material 2 or applying / etching a metal material to form a circuit. 4) is applied on the electrode 1 protruding from the electrical insulator 3, it is configured not to directly contact the conductive material (2).

That is, in the present invention, since the conductive material 2 such as PTCR is widely applied on the substrate which is the electrical insulator 3, the conductive material 2 may be applied over the entire surface of the substrate without having to match the positions of the conductive materials 2. When the conductive material 2 is dried to some extent, the electrode 1 may be formed by adjusting a relative position thereon.

In addition, since the adhesive 4 is applied after the formation of the electrode 1, the adhesive 4 is spaced apart from the conductive material 2 by the height of the electrode 1.

Therefore, when the conductive material 2 is energized by the electrode 1 to generate heat, the heat is not transferred to the adhesive 4 as it is, so that the adhesive 4 causes a chemical change to shorten its lifespan or the conductive material. (2) It does not generate abnormal heat.

On the other hand, in the present invention, the adhesive 5 is made of an insulating material such as an acrylic component, and is used for bonding to the rear surface of a heating target such as a rearview mirror.

That is, the present invention is a first coating of the PTCR material, that is, the conductive material (2) on top of the electrical insulator 3 (usually the film) of the plane, when using a certain thickness of coating and roller coating type of equipment by automated The production system is easy and the thickness control is possible by precision equipment, so when using as a heater, it is possible not only to realize various temperature characteristics, but also to obtain the effect of uniform temperature distribution.

In addition, since the adhesive 4 is bonded to the conductive material 2 with the electrode 1 interposed therebetween, it is possible to reduce the influence of the adhesive material on the PTCR heating element, resulting in chemical variation of the adhesive 4 at high temperatures. The abnormal change phenomenon of PTCR heating element can be reduced.

The manufacturing process is as follows.

As the electrode 1 is disposed on the thin and flat electrical insulator 3, and the conductive material 2 such as PTCR is disposed between the electrodes 1, the conductive material 2 is formed when the electrode 1 is energized. In the method of manufacturing a planar heating element using a conductive material to generate heat,

After dissolving a conductive material (2) such as PTCR in a solvent and applying it to the upper surface of the electrical insulator (3) by silkscreen printing or roller coating, etc.,

Primary heat treatment to remove the solvent contained in the conductive material (2),

The circuit 1 is formed by applying the conductive paste or applying / etching a metallic material, while forming the electrode 1 at a reference point to match the positions of the electrical insulator 3 and the conductive material 2 thereon.

The second heat treatment removes the solvent contained in the electrode 1, but also completely dry the conductive material 2 together.

In the conductive material (2), the heat treatment conditions should be set according to the product's required characteristics. However, most of the conductive materials (2) are dried for about 1 to 3 minutes at about 90 to 120 degrees higher than the boiling point of the organic solvent used for dissolving the polyolefin. The solvent will evaporate and will maintain a film form on the order of 7-15 microns.

On the other hand, the electrode (1) should be applied to the site where the conductive material (2) is applied, in order to prevent damage to the surface of the conductive material (2) during application of the electrode (1), do not dissolve the base resin of the PTCR material It is preferable to use a solvent having a non-property property.

In the case of the present applicant, a polyolefin-based resin is used as the binder of the PTCR material, that is, the conductive material 2, and chemical and other solvents are used as the polymer of the electrode 1 as the material of the electrode (1). 1) It is possible to maintain the existing flat film form without damaging the surface of the conductive material (2) during application.

On the other hand, in order to maintain the resistance value of the electrode (1) within an appropriate range, it is important to dry the solvent contained in the electrode material at a predetermined time. In this case, it is important that the drying temperature or time does not change the properties of the PTCR material.

In other words, it is necessary to set a drying condition to obtain an appropriate resistance value of the electrode without affecting the PTCR material.

Applicant was able to satisfy the properties of the PTCR material and electrode resistance at the same time by drying for 10 to 20 minutes in the drying conditions of 100 ~ 135 ℃, as a result of the effect of the process of reducing the secondary drying process of the PTCR material Got.

On the other hand, in order to improve the heating characteristics, as shown in Figure 2, the conductive material (2) (2 ') may be formed in a two-layer structure.

The conductive material (2) (2 ') is applied by a silk screen or roller type coating method by dissolving the PTCR material in a solvent, in the present invention, the conductive material (2') is applied on top of the conductive material (2) Since it is not applied directly to the electrode 1, the coating is applied with the electrode 1 interposed therebetween, so that the conductive material 2 'can be applied even without using a tool such as a squeeze without damaging the surface of the conductive material 2.

In this way, the conductive material (2) (2 ') can be applied thicker and more PTCR effect (resistance change with temperature increase) can be obtained in terms of performance. The effective temperature increase suppression effect can be obtained.

On the other hand, in the case of applying the conductive material (2) (2 ') in the double in this way is to apply the electrode (1) first to the first applied conductive material (2), and then to the second coating on it, In this case, special care should be taken so that the surface of the first conductive material 2 is not damaged by the solvent contained in the second conductive material 2 '.

In the case of the present applicant, when the secondary conductive material 2 'was applied to the drying furnace within 10 to 20 seconds, the surface shape was uniform.

In summary, in the present invention, when applying the conductive material (2) on the electrical insulator (3), it is only necessary to apply a wide range without a certain standard and only to maintain a certain reference point when applying the electrode (1), the outer Cutting is easy and process management is easy and PTCR application jig can be simplified.

In addition, since it is possible to work regardless of the reference point when applying PTCR material, not only screen printing using squeeze, but also mass printing such as roller type printing and roller type coating method is possible. Machining, electrode terminal connection, and outer line processing can be automated, greatly increasing productivity, and various coating methods can be applied, so that not only PTCR material having room temperature stability but also PTCR material having other characteristics can be used. will be.

On the other hand, in the conventional manufacturing process, the electrode 1 is usually applied and the first and second drying processes are performed to secure the proper resistance of the electrode circuit. Then, the PTCR material, that is, the conductive material 2, is applied thereon and then 1-2 times. In general, in the present invention, the conductive material 2 is applied and the first drying is performed, and then the electrode 1 is applied to carry out the first to second drying. By doing so, there is an advantage of simplifying the manufacturing process that can simultaneously proceed the secondary drying process of the conductive material (2).

In this case, the conductive material (2) and the electrode (1) that actually generates heat is exposed to the outside air, unlike the existing structure can obtain an appropriate drying effect.

As described above in detail, the conductive material 2 is first applied onto the substrate, which is the electrical insulator 3, and then dried, and then the electrode 1 is disposed thereon, thereby simplifying the manufacturing process and generating less defective rate. .

That is, in the past, since the electrode 1 was first disposed on the substrate, which is the electric insulator 3, and then the conductive material 2 was to be disposed thereon, the relative positions of the electrodes 1 had to be matched one by one. 3) Since the PTCR material, that is, the conductive material (2) is applied to the first, and then the electrode (1) must be formed thereon, at least when applying the conductive material (2), there is no need to check the relative position one by one. Make it much easier.

In addition, the adhesive 4 is not immediately adjacent to the conductive material 2, which is a heating element, but adjacent to each other with the electrode 1 interposed therebetween, thereby preventing the adhesive 4 from being excessively heated during use, thereby causing a chemical change of the adhesive 4. Do not shorten the life cycle or abnormal heating phenomenon.

In addition, even when the conductive material is made of a double bonded structure, the first and second conductive materials 2 and 2 'are not directly bonded, but are bonded together with the electrode 1 interposed therebetween. Even when silk screen printing the secondary conductive material 2 'by using a squeeze on the surface, the surface of the primary conductive material 2 is not damaged at all, so that the heat generation characteristics of the conductive material can be more uniformly formed. do.

Claims (5)

An electrode 1 is disposed above the thin and flat electrical insulator 3, and a conductive material 2 such as PTCR is disposed between the electrodes 1 so that the conductive material 2 generates heat when the electrode 1 is energized. In the planar heating element using a conductive material configured to The conductive material 2 is first applied on the electrical insulator 3, and the electrode 1 is formed by applying a conductive paste on the upper surface of the conductive material 2 or applying / etching a metal material to form a circuit. 4) is a planar heating element using a conductive material, characterized in that applied to the electrode (1) protruding from the electrical insulator (3). The planar heating element using a conductive material according to claim 1, wherein a second conductive material (2 ') is disposed between the electrode (1) and the adhesive (4). As the electrode 1 is disposed on the thin and flat electrical insulator 3, and the conductive material 2 such as PTCR is disposed between the electrodes 1, the conductive material 2 is formed when the electrode 1 is energized. In the method of manufacturing a planar heating element using a conductive material to generate heat, After dissolving a conductive material (2) such as PTCR in a solvent and applying it to the upper surface of the electrical insulator (3) by silkscreen printing or roller coating, etc., Primary heat treatment to remove the solvent contained in the conductive material (2), The circuit 1 is formed by applying the conductive paste or applying / etching a metallic material, while forming the electrode 1 at a reference point to match the positions of the electrical insulator 3 and the conductive material 2 thereon. Method of manufacturing a planar heating element using a conductive material, characterized in that the second heat treatment to remove the solvent contained in the electrode (1) but also completely dry the conductive material (2). 4. The conductive material as claimed in claim 3, wherein a polyolefin resin is used as the binder of the conductive material 2, and chemical and other solvents are used as the polymer of the polyester as the binder of the electrode 1. Method for producing a planar heating element using a material. The method according to claim 3 or 4, wherein the electrode 1 and the conductive material 2 are dried, and then the second conductive material 2 'is applied on the upper part by silkscreen printing or roller coating. And heat treating again to remove the solvent contained in the conductive material (2 ').