JPS5968187A - Terminal structure - 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 (1) Technical Field of the Invention The present invention relates to a terminal structure such as a conductive terminal inserted into a through hole of a printed circuit board or a contact pin of a connector.

(2) Background of the technology Generally speaking, there are two methods for fixing conductive terminals that transmit electrical signals to printed circuit boards: one is to insert the terminal into a through-hole and fix it by soldering, and the other is to press-fit it into the through-hole and connect it without soldering. However, since the former involves various manufacturing problems due to the soldering process involved, there is a growing demand for the development of highly reliable terminal joining structures using the latter method.

(3) Conventional technology and problems As a method of fixing terminals such as contact bins of connectors to through holes of printed circuit boards without soldering,
Conventionally, the terminal structure shown in FIG. 1 is well known. FIG. 1(a) is a cross-sectional plan view showing the relationship between the printed board through-hole and the terminal joint, and FIG. 1(b) is a perspective view of the main part of the terminal. In the figure, the terminal 1 has a rigid structure, and as shown in Figure (b), the terminal 1 has a contact side 11,
It consists of a joint part 12 and a terminal part 13. The joint part 12 is joined to the printed board through hole 10, and the terminal part 13 is mainly used as a wrapping terminal.

This rigid terminal joint portion 12 is inserted into a through hole 10 of a printed circuit board as shown in FIG. At this time, the terminal joint and the inner wall of the through hole are A.

It contacts and is fixed at four locations B, C, and D. However, in this terminal structure, due to the rigidity of the joint part 12, there is a risk of destroying the through hole, such as by cutting out parts A, B, C, and D of the inner wall of the through hole. It is easy to defeat the purpose.

In order to solve this problem, terminal structures as shown in FIGS. 2, 3, and 4 have been provided or proposed. Throughout FIGS. 2 to 4, the same reference numerals used in FIG. 1 indicate the same objects, and the relationships between FIGS. A perspective view of the main parts is shown.

FIG. 2 shows a flexible structure in which the terminal joint portion 22 has a C-shaped cross section. As shown in FIG. 2(a), since the joint portion 22 makes surface contact with the through hole, destruction of the through hole 10 can be prevented.

FIG. 3 shows a terminal with a flexible structure in which the terminal joint portion 32 has a slotted shape. Put a slot in the center of the joint 32 and insert 3 on each side.
21 and 322 are in opposite directions (arrow 3 in Figure 3(a)
6) is bent. When this joint 32 is inserted into the through hole 10, a force is generated in the direction in which the sides 321 and 322 spread apart due to the elastic force, and the two sides of the inner wall of the through hole
Contact is fixed at points A and B.

FIG. 4 shows a joint portion 42 having a V-shaped (or U-shaped) cross section and a flexible structure. This terminal has three contact points A, B, and C with the through hole, and is fixed in contact with the through hole due to the elasticity produced by the V-shaped (or U-shaped) cross section of the joint.

However, even with the above configuration, the manufacturing process requires complicated processing steps (Figs. 2 and 3), and it is vulnerable to the rotational moment about the axis of the terminal such as a contact (
(Fig. 2, Fig. 3, Fig. 4), the printed board tends to be distorted in one direction due to uneven contact force (Fig. 3), and the contact inside the through hole tends to be uneven. The tube had various problems (Figs. 2 and 4) and was quite unreliable.

(4) Purpose of the Invention In order to solve the problems caused by the conventional terminal structure, the present invention provides elasticity to the terminal joint, maintains stable contact with the through hole, and improves manufacturability. The purpose is to provide a good terminal structure.

(5) Structure of the Invention According to the present invention, in a conductive terminal that is inserted and connected to a through-hole button of a printed board, the joint portion that makes contact with the through-hole is composed of four inscribed edges; The cross-sectional shape is such that one side is an I-shaped convex part, and the other side is formed as a substantially concave part, and the apex of each of the convex part and the concave part has an apex angle of the convex part. Also, the concave portion is made smaller, the width of the central part of the cross section is made thinner than the width of both ends, and the vicinity of the central part is provided with spring properties, and the contact points (four locations) with the through hole are mutually connected. By dispersing the pressure applied to the through hole and preventing damage to the through hole, when the joint portion of the terminal is inserted and fixed into the through ball, the apex of the convex portion is placed on the inner wall of the through hole. This is achieved by a terminal structure that does not touch the

(6) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 5 is a diagram for explaining the terminal structure according to the present invention, in which FIG. 5A shows a cross-sectional shape of the terminal joint portion together with a through hole, and FIG. 5B shows a perspective view of the main part of the terminal.

In the figure, the terminal 5 has a contact side 51, a joint part 52,
The joint portion 52 has a cross-sectional shape of a
As shown in the figure, the hole inscribed in the through hole 50 is butterfly shaped AB.
One of the opposing long sides of CDEF, BCD, forms a hexagonal convex portion, and the other side AFE forms a hexagonal concave portion, and the apex angle of the concave portion is smaller than that of the convex portion. There is. Therefore, the wall thickness is thinner at the center than at both ends, and springiness is mainly imparted to the center.

The joint portion 52 formed in this way contacts the inner wall of the through hole 50 at four points A, B, D, and E, and since it has a flexible structure with a bent cross section, each contact point A, B, D, and E is formed. Press outward with . Due to its spring properties, the joint 52 shifts so that the forces are balanced at each contact part, and presses against the inner wall of the through hole when it stabilizes, so that the contact part of the joint slightly dents the inner wall of the through hole and the axis Prevents terminal rotation due to rotational moment. In addition, as mentioned above, in order to make it easier for the terminal joint to shift to a position where the force is balanced inside the through hole, each contact point A, B, D is
, E performs a hammer stroke to eliminate the sharp angle. Then,
By facing the through hole, the through hole and the joint come into contact at an obtuse angle or a plane, and stress concentration does not occur, so destruction of the through hole can be avoided.

(7) Effects of the Invention As explained in detail above, the terminal structure according to the present invention has a cross-sectional shape of the joint part that is thin in the center and thick at both ends, and has a bent shape to give it spring properties. This has a great effect in that the contact points of the two are separated from each other, and the springiness improves the connection with the through-hole.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are views showing conventional terminal structures, and FIG. 5 is a view showing the construction of a terminal 4 according to the present invention. In the drawings, 5 is a terminal, 50 is a through hole, 51 is a contact side, 52 is a joint portion, and 53 is a terminal portion. Patent Applicant Fujitsu Limited Nippon Telegraph and Telephone Public Corporation Patent 1:l:II Patent Attorney Akira Yoiki Patent Attorney Kazuyuki Nishidate Patent Attorney 1) Yukio Patent Attorney Akira Yamaguchi Figure 1 Figure 2

Claims (1)

[Claims] In a conductive terminal that is inserted and connected to a through hole in a printed circuit board, the joint part that makes contact with the through ball is made up of four inscribed edges, and the cross-sectional shape is such that one side is a substantially hemlock-shaped convex part and the other side is The other surface of the convex portion and the concave portion are formed into four substantially hemlock-shaped parts, and the apex angle of each of the convex portion and the concave portion is smaller than that of the convex portion, and the width of the central portion of the cross section is equal to the width of both ends. The terminal structure is characterized by being thinner and having spring properties near the center.