JPS60258903A - Electronic part - 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 The present invention relates to an electronic component formed with attached electrodes of a conductive plastic base material.

In recent years, conductive plastics with positive temperature characteristics have been developed, which are made by kneading and crosslinking conductive agents such as carbon into a base material of polymeric materials such as polyethylene. It is formed into a plate piece to form the element body 1, and a metal foil electrode 2.2 is attached to the main surface by thermocompression bonding or the like, and is used as an electronic component for current suppression or the like.

By the way, when used as such an electronic component, the element generates heat due to electric current, so turning on and off the current will cause the element to heat up.
A heating and cooling cycle is added, but since the coefficient of thermal expansion of the plastic element body 1 and the metal N2 is one order of magnitude larger than that of the latter, the metal foil 2 is Easy to peel off from main body 1,
Particularly, as shown in FIG. 8, peeling easily progressed from the end B of the metal N2.

The present invention has been made in view of the above circumstances, and includes:
By improving the metal foil electrodes attached to the conductive plastic element body, the objective is to make the electrodes less likely to peel off even during heating and cooling cycles.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. As shown in FIG. 1, the electronic component according to the present invention has electrodes 2.2 made of metal foil in the shape of four meshes on the opposing main surfaces of an element body 1 made of conductive plastic formed into a rectangular or circular plate. It is configured by being attached by means such as hot press welding.

As shown in FIG. 2, the electrode 2 is formed into a mesh pattern in which hexagonal holes 3 are punched out in close parallel rows and columns. This relative displacement is absorbed by the deformation of the thin linear portion 2a. As in this example, the mesh pattern of the hexagonal holes 3 has no directionality in its ability to absorb the relative displacement, and exhibits a good dimensional absorption effect against expansion and contraction in all directions. In addition, when the electrode 2 is welded to the main surface of the element body 1 by hot pressing, the linear portion 2a as shown in FIG.
Since it slightly bites into the element body 1 to form a mesh shape, the bonding strength is high, and the linear portion 2a deforms well to follow the thermal deformation of the element body 1. Note that the mesh pattern may be one in which round holes 4 are punched vertically and horizontally as shown in FIG. is formed zh, :
, :'r's displacement absorption function is slightly inferior, and overall it is ranked second.
The peeling resistance is slightly inferior to that of the mesh pattern shown in the figure.

Figure 6 shows the variation characteristics of the rate of change in interelectrode resistance with respect to on/off of current supply between the electrodes, for the case with the hexagonal mesh pattern electrode in Figure 2 (a), and for the electrode material with the mesh pattern in Figure 4. In the case of g (b), and in the case of the conventional product shown in Fig. 7 (c)
As is clear from the figure, in the case of a hexagonal hole pattern with no directionality in its displacement absorption function (
Characteristics (a) are the most stable and durable, followed by round hole pattern (b) which is relatively stable and durable, and full electrode (c) which has the lowest stability and durability. is recognized.

In addition, as a mesh pattern other than the above, it is also possible to form a group of round holes 4 with a phase shift of half a pitch for each row as shown in FIG. 5, and in this case, the pattern shown in FIG. Almost the same characteristics can be obtained.

As described above, according to the present invention, the metal foil electrode attached to the main surface of the element body made of conductive plastic with a high expansion/contraction rate is formed in a mesh shape, so that large thermal deformation of the element body is avoided. In contrast, the mesh part of the electrode becomes easier to follow and deform, and the electrode is less likely to peel off even after repeated expansion and contraction due to heating and cooling, making it possible to stabilize electrical characteristics and improve durability. . Furthermore, the edge length of the mesh metal foil in contact with the main surface was extremely long, and the edge length of each metal foil bit into the element body, increasing the bonding strength of the electrode as a whole.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an electronic component according to the present invention, FIG. 2 is an enlarged view of an electrode, FIG. 3 is a sectional view taken along line A-A with respect to FIG. 2, and FIG. 4 is another embodiment of an electrode mesh pattern. Enlarged diagram showing an example,
Fig. 5 is an enlarged view of yet another embodiment of the electrode mesh pattern, Fig. 6 is a characteristic diagram of electronic components with various electrodes, Fig. 7 is a perspective view of the conventional product, and Fig. 8 is the conventional product. FIG. 1 is the element body, 2 is the electrode. Applicant: Material Manufacturing Co., Ltd. Patent Attorney Oka 1) Hide Kazu-4= Figure 1 Figure 2 Figure 3 Figure 6 Figure 7 Figure 8 Figure 4 Figure 5

Claims (2)

[Claims] (1) An electronic component comprising an electrode 2 made of mesh metal foil attached to the main surface of an element body 1 made of conductive plastic. (2) The mesh of the electrode 2 is formed in a pattern in which the metal foil portions are not continuous in a straight line.
Electronic components listed in section.