JPS62256404A - Positive characteristics thermistor device - 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 positive temperature coefficient thermistor device in which an electrode plate for voltage supply is securely connected to an electrode formed on a positive temperature coefficient thermistor element.

Conventional technology In recent years, positive temperature coefficient thermistor elements have been developed due to their unique characteristics.
It is widely used in various heating elements, degaussing elements for color television receivers (tie), side legs of motors with excessive torque, and current control in various circuits.

As a means of connecting the electrode plate for voltage supply,
A means of pressure-welding connection using a mechanical mechanism.

Connection means by soldering, connection means by conductive adhesive, means by pressure contact with insulating adhesive, etc. are used.

Among these measures, reliability, heat resistance,
From the viewpoint of cost, etc., pressure bonding using an insulating adhesive is mainly used.

Hereinafter, with reference to the drawings, the above-described conventional pressure-welding means for connection using an insulating adhesive will be described.

FIG. 4 and FIG. 5 show a connection state using a conventional means of press-contacting and connecting with an insulating adhesive. In FIG. 4, 1 is a positive temperature coefficient thermistor element, 2 is an electrode formed on the positive coefficient thermistor element 1, 4 is an insulating adhesive, and 3 is a positive temperature coefficient thermistor element.
1 shows electrode plates made of thin plates such as aluminum, and each electrode plate 3 is connected to a lead wire (not shown in the drawing) for supplying voltage depending on the purpose.

FIG. 5 shows an electrode 2 formed on a positive temperature coefficient thermistor element 1.
FIG. 3 is an enlarged cross-sectional view showing a connection state between the electrode plate 3 and the electrode plate 3. FIG. Fifth
In the figure, an electrode 2 formed on a PTC thermistor element 1 and an electrode plate 3 are partially connected via an insulating adhesive 4 (a is a non-contact part, b is a contact part).

The connection means in this case is to apply an insulating adhesive 4 such as silicone resin to one side of the electrode 2 formed on the PTC thermistor element 1 and the electrode plate 3 connected to this electrode 2, and to The connection is achieved by heating and curing while applying pressure, or by applying a predetermined voltage to the PTC thermistor element 1 and using self-heating of the PTC thermistor element 1 to cure the PTC thermistor element 1.

The operation of the positive temperature coefficient thermistor device connected by the means described above will be explained below. First, when a predetermined voltage is supplied from the lead wire, the voltage is applied to the electrodes of the PTC thermistor element through each electrode plate, and the PTC thermistor element operates. At this time, the voltage is applied when the electrode of the positive temperature coefficient thermistor element and the electrode plate are in partial contact, as shown in FIG.

Problems to be Solved by the Invention However, the above connection configuration has the following drawbacks.

(1) The contact between the electrode formed on the positive temperature coefficient thermistor element and the electrode plate is only partial.

(2) When a PTC thermistor element is used in actual operation over a long period of time, differences in thermal expansion coefficient due to differences in the materials of the PTC thermistor element, electrodes, electrode plates, insulating adhesives, etc., especially between the electrodes and the electrode plate. The contact is broken due to the insulating adhesive between the two.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned drawbacks and provide a positive temperature coefficient thermistor device with excellent connection between electrodes formed on a positive temperature coefficient thermistor element and an electrode plate.

Means for Solving the Problems To achieve this object, the PTC thermistor device of the present invention has an electrode plate having a plurality of protrusions and a plurality of holes, and the protrusions are connected to electrodes formed on a PTC thermistor element. The insulating adhesive is pressed against the positive temperature coefficient thermistor element and connected to the positive temperature coefficient thermistor element.

Operation With this connection form, the electrode formed on the PTC thermistor element and the electrode plate are connected by a plurality of protrusions formed on the electrode plate entering into the electrode on the PTC thermistor element by pressure contact and making contact. In addition, the insulating adhesive existing between the electrode plate and the electrode formed on the PTC thermistor element comes out from the plurality of holes provided in the electrode plate due to pressure contact, so the amount of the insulating adhesive present is small. This is significantly smaller than that without holes, so the effect (force that attempts to break contact due to thermal expansion) is reduced. In other words, the plurality of protrusions provided on the electrode plate directly enter and contact the electrodes on the PTC thermistor element by pressure contact, and the insulating adhesive that affects the contact state is inserted into the holes provided in the electrode plate by pressure contact. Since the amount existing between the two is extremely small, the connection will remain in good condition even after long periods of actual use.

Example Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the connection state in an embodiment of the present invention.
FIG. 2 shows an enlarged view of the connecting portion, and FIG. 3 shows the electrode plate.

In FIGS. 1, 2, and 3, 6 is, for example, BaTi.
An O3-based positive temperature coefficient thermistor element, 6 an electrode made of, for example, 0.211 nlt aluminum, formed on the positive temperature coefficient thermistor element S, 7 an insulating adhesive usually made of silicone resin, 8 a plurality of protrusions 8a. and multiple holes 8
This electrode plate 8 is pressed and connected to the PTC thermistor element 6 via an insulating adhesive 7 with its protrusion 81L facing the electrode 6 side.

Here, in the configuration as described above, for example, 3
0kq/c! A sample prepared by curing in a dryer at 180°C for 2 hours while applying a pressure of
C) was applied for 1 a minute and then off for 15 minutes to evaluate its reliability.
Compared to the electrode plate shown in the figure, which has no protrusions or holes, its life span (the time it takes to become completely electrically open) has been improved by approximately three times.

The reason why such an effect was obtained in the present invention is as follows.

(1) A plurality of protrusions provided on the electrode plate sink into the electrode formed on the PTC thermistor element, thereby improving the contact state between the two.

(2) The insulating adhesive existing between the electrode plate and the electrode on the PTC thermistor element is connected by applying pressure, and the excess material is expelled from the hole provided in the electrode plate.
The amount is small, and the effect of thermal expansion of the insulating adhesive during actual use (force to remove the electrode plate from the electrode) is extremely small, and at the same time, due to the synergistic effect with (1) above, it can last for a long time. Reliability in use can be improved.

In the above embodiment, the electrode plate 8 was made of aluminum, but it may be made of other metal materials as long as the same purpose can be achieved, and the size and number of the protrusions and the size and number of holes are determined depending on the purpose. You can choose accordingly. Further, the pressure is not limited to 30 kq/cd shown in the example, but may be selected depending on the material of the electrode plate and the size and number of projections and holes so as to obtain the same effect.

Effects of the Invention As described above, the present invention improves reliability by connecting an electrode plate provided with a plurality of protrusions and a plurality of holes to an electrode on a positive temperature coefficient thermistor element through an insulating adhesive. This can be significantly improved and has great practical effects.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the configuration of a positive temperature coefficient thermistor device according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of the main parts showing the connection state of the present invention, and FIG. FIG. 4 is a sectional view showing the configuration of a conventional PTC thermistor device, and FIG. 5 is an enlarged sectional view of main parts showing a conventional connection state. 5... Positive temperature coefficient thermistor element, 6... Electrode, 7... Insulating adhesive, 8... Electrode plate, 8a... Electrode Protrusion of plate, 8b...
Hole in electrode plate. Name of agent: Patent attorney Toshio Nakao and one other person
4 Figure

Claims (1)

[Claims] An electrode plate having a plurality of protrusions and a plurality of holes is connected to the PTC thermistor element by pressing the protrusions against the electrode formed on the PTC thermistor element via an insulating adhesive. Characteristic thermistor device.