KR0183371B1 - Temperature coefficient sector - Google Patents

Abstract

It is an object of the present invention to provide a positive temperature coefficient device having a new structure which has better processability than a conventional noon degree coefficient device and can suppress a negative temperature coefficient phenomenon generated when a certain temperature is exceeded. .

The present invention inserts a networked or fibrous metal layer between two sheets of positive temperature coefficient sensors processed by dispersing / collecting carbon black onto a flat matrix represented by a polyolefin resin and processing them into a flat plate, and on the outer surface of the positive temperature coefficient sensor. The above object is achieved as a positive temperature coefficient element constituted by forming an electrode on a metal.

Description

Positive temperature coefficient element

1 is a process diagram schematically showing a manufacturing process of a positive temperature coefficient device according to the present invention,

2 is a block diagram of a positive temperature sensor unit of the positive temperature coefficient device according to the present invention,

3 is a cross-sectional view showing the overall configuration of the constant temperature coefficient device according to the present invention,

4 is a graph showing a change in volume resistance according to the temperature of the positive temperature coefficient element having a structure according to the present invention.

* Explanation of symbols for main parts of the drawings

1: Positive temperature sensor 2: Thermal diffusion / structural stabilizer

3: electrode 4: insulation moisture proof coating

5: electrical lead wire

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant temperature coefficient device that can be used for temperature and current control of various electronic products, automobiles, aircrafts, ships, and the like, in particular, at a low threshold temperature of about 110 ° C. by structural control of the device. The present invention relates to a constant temperature coefficient element of a new structure having a characteristic of rapidly increasing the value of volume resistance.

As the technology of semiconductors and various electronic components is made rapidly, the degree of integration of electronic circuits is also rapidly increasing. Devices are being used. The most common one is a fuse, but the fuse has a problem that the constant temperature coefficient is bad, so that it does not operate sensitively due to changes in the environment. Accordingly, there is a demand for the development of a new type of constant temperature coefficient device capable of operating more sensitively according to external environmental changes. As such a material, a constant temperature counting element currently used as a representative may be a constant temperature counting element of Raychem of the United States. This device adds metallic electrodes on both sides of a substrate in which carbon black is dispersed and collected on a polymer matrix such as polyethylene, and has a shoulder point around 125 ° C. This device has a simple structure and shows a sensitive sensitivity to the temperature change of the external environment compared to the above-mentioned fuses, but is characterized by poor workability because the carbon black content is very high during manufacturing. Accordingly, an object of the present invention is to provide a constant temperature counting device having a new structure having better processability as compared with a conventional constant temperature counting device.

In order to achieve the above object, the present invention inserts a network or fibrous conductive material layer between two positive temperature coefficient sensors processed by dispersing / collecting carbon black onto a flat matrix represented by a polyolefin resin to form a plate. The present invention provides a constant temperature counting element comprising a metal electrode formed on an outer surface of a constant temperature counting sensor.

In the above, the conductive material layer may be formed in various forms. For example, it may be in the form of a metal mesh, or a mesh or fiber of a heat resistant high molecular material coated with a metallic material. In the case of a metal mesh, 20 to 325 mesh copper, brass, or tin coated copper or brass mesh may be used. Metallic Coatings As the net or fibrous material of the heat resistant high molecular material, for example, polyethylenphthalate, polyphenylene sulfide, or aromatic polyamide resin coated with tin or nickel may be mentioned.

In the constant temperature coefficient device having the configuration according to the present invention described above, the polyolefin resin is composed of low density polyethylene, high density polyethylene, or polypropylene alone or as a mixture. Carbon black is added in an amount of 10 to 50% by weight, preferably 10 to 40% by weight, based on the polyolefin resin described above. When carbon black is dispersed and collected in a polyolefin resin, structural cracks of polyolefins acting as a matrix may occur, and thus, crosslinking agents, crosslinking aids, and antioxidants for suppressing negative temperature coefficients commonly used in processing polyolefin resins may be seen. It can be used within the range which does not change the characteristic of the positive temperature coefficient element of this invention.

In the present invention described above, the metal or metal-coated high-rich material inserted between the constant temperature coefficient sensor portion functions as a structural stabilizer against diffusion, cracking and thermal deformation of the constant temperature coefficient sensor, and the volume resisting shoulder of the sensor This will lower the point considerably (see Figure 4).

Next, the present invention will be described in more detail with reference to preferred embodiments of the present invention. However, the following embodiments are merely provided to more easily understand the present invention, but the present invention is not limited thereto.

EXAMPLE

First, a crystalline high density polyethylene [manufacturer; Korea Yugong Co., Ltd., a brand name: JH 910 and carbon black (manufacturer: Denga, Japan: Denka black) are each dried at 60 ° C / 24 hours.

25% by weight, 0.5% by weight of carbon black, antioxidant, a crosslinking agent, and a crosslinking aid, which were vacuum dried under the same conditions in a high-density polyethylene vacuum dried using a conventional mixing device such as a super mixer, respectively, 0.5% by weight and 0.5% by weight are added and mixed to complete the primary mixing process.

This is fed into a biaxial mixing injector and injection-molded into a ferret at a temperature of 150 to 180 ° C.

This ferret is put into a thermocompression die and the thermocompression molding is processed into a flat plate 1 for 2 to 10 minutes at a temperature of 150 to 180 ° C. with a pressing force of 180 to 250 kg / cm 2.

The copper or brass plate (thickness: 30-50 μ) is etched through a separate work process, and then tin-plated and cut into the required size to form a flat electrode 30, and the tin-plated 300 mesh brass mesh 2 is second. Inserted into the center layer as shown in the figure, the plate electrode 3 is placed on both sides of the outer surface of the plate-shaped constant temperature coefficient sensor 1, and placed in a thermocompression molding die at a pressure of 200 to 250 kg / cm 2 and a temperature of 170 to 210 ° C. Secondary cross-linking processing is performed for 10 minutes The electrode 5 is completed by soldering or otherwise joining the conductive wires 5 to both of the flat electrodes as shown in FIG.

The surface protective coating (4) is carried out with epoxy to 50-200 mu in thickness as shown in FIG. The surface-coated specimen is subjected to a heat treatment process at a temperature of 80 to 130 ° C. for 1 to 3 hours to complete the specimen of the noon counting element. The completed positive temperature coefficient element has a characteristic of initial volume resistance of 100 Pa.cm (25 占 폚) and a volume resistive shoulder temperature of 115 占 폚.

[Comparative Example]

In the above embodiment, the heat diffusion and the structural stabilizer in the form of a metal net was substantially the same as the embodiment except that it is not inserted between the constant temperature coefficient sensor unit.

The positive temperature coefficient device manufactured according to the present invention exhibited a volume resistive shoulder point of 125 ° C as shown in FIG. In addition, at 80 ° C., the current is limited to approximately 810 Ω · cm, so that the current is limited enough to exhibit significant heat generation before reaching the operating point of 135 ° C., thus the operating current range is narrowed, which is very disadvantageous.

Claims (5)

A network or fibrous conductor is inserted between two sheets of positive temperature coefficient sensors processed by dispersing / collecting carbon black into a flat plate shape on a polymer matrix represented by polyolefin resin, and a metal phase is placed on the outer surface of the positive temperature coefficient sensor. A positive temperature coefficient element, consisting of, forming an electrode. The device of claim 1, wherein the conductor material is a mesh or fibrous metal material. The constant temperature coefficient device of claim 1, wherein the conductor material is an enamel or fibrous heat-resistant polymer material coated with a metal material. The positive temperature coefficient device according to claim 1, wherein the polyolefin resin is selected from the group consisting of low density polyethylene, high density polyethylene, or polypropylene alone or in a mixture thereof. The positive temperature coefficient device according to claim 1, wherein the carbon black is added in an amount of 10 to 50% by weight based on the polyolefin resin.