JPS6236371B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electronic components, and particularly to the configuration of electrode terminals thereof.

To assemble an electronic circuit, holes are drilled into a so-called printed wiring board, which has the required conductor pattern formed on its surface in advance, into which electrode terminals for various electronic components such as resistors, capacitors, semiconductor elements, and connectors are inserted. A very widely used method is to insert electrode terminals of required electronic components into these holes and connect them to the conductor pattern.

FIG. 1 shows a state in which electronic components are mounted on a printed wiring board by a conventional method, FIG. 1A is a plan view thereof, and FIG. 1B is a side view thereof. In the figure, 1
2 is a printed wiring board, 2 is a conductor pattern formed on its surface, 3 is a hole formed from above the conductor pattern 2 through the printed wiring board 1, 4 is an electronic component, and 5 is an electrode of the electronic component 4. At the terminal, hole 3 each
and is fixed with solder 6. After inserting the electrode terminal 5 into the hole 3, bend it if necessary, and then apply solder 6.
It is fixed at

However, with these conventional methods, the soldering process is troublesome, and if the solder does not flow properly, it may cause electrical or mechanical contact failures, which may reduce the reliability of electronic circuits. Ta.

The present invention has been made in view of the above points, and an object of the present invention is to provide an electronic component having an electrode terminal structure that is easy to attach to a printed wiring board and can provide reliable contact.

FIGS. 2A and 2B are perspective views showing the first and second embodiments of the present invention, respectively, and 5a is an electrode terminal using a shape memory alloy, which is the main point of the present invention. Shape memory alloy is, for example, titanium (Ti)-
It has a composition such as nickel (Ni) alloy, copper (Cu)-aluminum (Al)-zinc (Zn) alloy, etc., and when it is formed into the desired shape, it becomes plastic at the stage of martensitic state at low temperature. When deformed and then the temperature is raised, the crystalline state returns to its original state and the shape also returns to the shape before plastic deformation. Therefore, as in the illustrated embodiment, the electrode terminal 5a of the electronic component 4 is made of a shape memory alloy,
As shown in FIG. 3, the shape of the printed wiring board at a temperature around room temperature (high temperature phase) is inserted into the hole 3 of the printed wiring board 1. Make it into a shape that tightens 1.

In order to mount such electronic components 4 on the printed wiring board 1, all the electronic components 4 are brought to a low temperature so that their electrode terminals 5a are in a martensitic state, and in this state, the electrode terminals 5a of each electronic component 4 are Insert into the required hole 3. At this time, each electrode terminal 5a easily undergoes plastic deformation and can be easily inserted into the hole 3 manually or by an automatic machine. After inserting all the electrode terminals 5a, when the temperature is raised and returned to a temperature slightly higher than room temperature, the crystalline state of the shape memory alloy returns to its original state, and the shape of the electrode terminals 5a returns to its original shape. As shown in FIG. 3, it is fixed to the printed wiring board 1 with reliable electrical and mechanical contact. Even if the temperature rise is insufficient and the electrode terminal 5a is not fixed enough, by passing current, heat is generated in the electrode terminal portion with poor contact, promoting recovery of the shape and electrically Mechanical contact is good.

Note that the shape of the electrode terminal is not limited to the above example.
Needless to say, you can choose any one you like depending on your needs.

As explained above, since the electronic component according to the present invention uses a shape memory alloy for the electrode terminal, mounting on the printed wiring board for assembling the electronic circuit is easy.
It is extremely easy to insert only at a low temperature and does not require a soldering process, and after passing through a high temperature phase, sufficient electrical and mechanical contact is ensured, improving assembly reliability.

[Brief explanation of the drawing]

FIG. 1 shows a state in which electronic components are mounted on a printed wiring board by a conventional method, FIG. 1A is a plan view thereof, and FIG. 1B is a side view thereof. FIGS. 2A and 2B are perspective views showing the first and second embodiments of the present invention, respectively, and FIG. 3 is a side view showing how these embodiments are mounted on a printed wiring board. In the figure, 1 is a printed wiring board, 3 is a hole, 4 is an electronic component, and 5a is an electrode terminal. In addition, in the figure,
The same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. It is composed of a shape memory alloy, and at room temperature (high temperature phase), it has a shape that tightens the printed wiring board with the outer circumference of the hole into which it is inserted, and in a low temperature martensitic state, it easily fits into the hole of the printed wiring board. An electronic component characterized by having an electrode terminal that can be inserted.