JPS61255002A - Manufacture of positive temperature coefficient thermistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a positive temperature coefficient thermistor.

Conventional positive temperature coefficient thermistors are generally used for low-power heaters, and heat-shrinkable chains are often used for their insulating jackets because they are inexpensive. There are two types of PTC thermistor elements: cylindrical and plate-shaped.If the cylindrical element is covered with the above-mentioned heat-shrinkable tube and exposed to hot air or passed through a heating furnace, it will be relatively stable. A uniform coating can be achieved by inserting a plate-shaped positive temperature coefficient thermistor element 3 between two electrode plates 1 and 2 and covering it with a heat-shrinkable tube 4 as shown in FIG. When heated, the open end 4a of the heat-shrinkable tube 4 is not covered in a flat shape, but is formed into a cylindrical open state. Therefore, even if electricity is applied between the electrode plates 1 and 2 of the PTC thermistor to generate heat, the PTC thermistor does not come into close contact with the object to be heated 5, and a gap 8 is created, resulting in very poor heat conduction. It could not function as a heater.

Means for Solving the Problems The present invention solves the above-mentioned problems by sandwiching a plate-shaped positive temperature coefficient thermistor between electrode plates, surrounding the electrode plates and the positive temperature coefficient thermistor element with a heat-shrinkable tube, and then This is a method for manufacturing a characteristic thermistor, which is characterized in that it is pressed with a heating jig and thermally contracted.

After the heat-shrinkable tube is surrounded by the action plate-shaped PTC thermistor element, it is pressed with a heating jig and heat-shrinked, so that each layer of the electrode plate, the PTC thermistor element, and the heat-shrinkable tube is pressed. Since the coating is performed at the bottom, the open end does not open into a cylindrical shape, and the above-mentioned layers are coated in close contact with each other.

Therefore, when a positive temperature coefficient thermistor is brought into contact with an object to be heated and energized, the thermal conductivity is significantly improved and the temperature rise characteristics are improved.

EXAMPLES Hereinafter, the present invention will be explained with reference to examples shown in FIGS. 1 to 4 and 7.

Silver electrodes are coated on both sides as the positive temperature coefficient thermistor element 3,
Using an element with a diameter (iu) and a thickness of 2.5 m at a cue point of 70°C, it has lead-out terminal pieces 1a and 2a, and has a width of 8 squares, a length of 811 mm, and a thickness of 0.3 tm. The above-mentioned positive temperature coefficient thermistor element 3 is sandwiched between tin-plated brass terminal plates 1 and 2 with the dimensions of , and as shown in Fig. 2, an H type made by Tijin Kasei ■ has a thickness of 100 μm, a diameter of 8 mm, and a length of 20 m. After surrounding it with a polyester heat-shrinkable tube 4,
As shown in FIG. 3, a heating jig 6.7 heated to 200° C. is pressed from above and below for about 5 seconds to cause heat shrinkage, and the product is completed as shown in FIG. 1.

FIG. 7 shows positive temperature coefficient thermistors manufactured based on the method of the present invention according to the above-mentioned embodiments and the conventional method, respectively.As shown in FIG. 5 is pressed by a spring and 18 VAC is applied between the terminals 1a and 2a of the positive temperature coefficient thermistor, and the temperature of the heated object 5 is measured.The sample produced by the method of the present invention (curve a in the figure) It has been demonstrated that the heat conduction is better than that of the sample produced by the conventional method (the curved line in the figure), and that the temperature of the heated object can be raised in a short time.

Although various materials can be used for the heat-shrinkable tube 4, it is particularly effective when covering a plate-like laminate with a relatively hard material such as polyester. It is effective not only when using one sheet but also when multiple sheets are stacked. If the planar area of the PTC thermistor element 3 is relatively small and the thickness is large, by providing a recess 7a in the heating jig 7 and pressing it as shown in FIG.
Can be coated more uniformly.

Effects of the Invention According to the method for manufacturing a PTC thermistor of the present invention, a heat-shrinkable tube can be uniformly coated along the plane of a plate-shaped PTC thermistor element, and a PTC thermistor with good thermal conductivity can be obtained. It is extremely advantageous in terms of productivity and has great industrial and practical value.

[Brief explanation of drawings]

1 to 4 show examples of the method of the present invention, in which FIG. 1 is a sectional view of a PTC thermistor, FIGS. 2 to 4 are perspective views of a PTC thermistor in the manufacturing process, and FIGS. FIG. 6 shows a PTC thermistor according to the conventional method, FIG. 5 is a perspective view, FIG. 6 is a sectional view, and FIG. 7 is a diagram comparing the temperature rise characteristics of the PTC thermistor according to the method of the present invention and the conventional method.

Claims (1)

[Claims] A positive temperature coefficient thermistor element characterized by sandwiching a plate-shaped positive temperature coefficient thermistor element between electrode plates, covering the electrode plate and the positive coefficient thermistor element with a heat-shrinkable tube, and then pressing it with a heating jig to heat-shrink it. A method of manufacturing a thermistor.