JPS6258170A - Probe contact - Google Patents

Abstract

PURPOSE:To attain to enhance the test accuracy of a printed wiring board, by forming a notch part to a slide part to impart elasticity to said slide part. CONSTITUTION:A plunger contact 14 is constituted of the leading end 16 contacted with a surface to be measured, the slide part 17 sliding with a body part 12, the notch part 22 formed to the leading end of the slide part 17 and the rubber like elastomer 23 engaged with and fixed to the bottom part of the notch part 22. When the leading end 16 of the plunger contact 14 is contacted with the solder surface 19 of a printed circuit board 18, even if strong force is applied to the slide part 17 from the lateral direction, the slide part 17 is elastically contacted with the body part 12 in a freely slidable manner by the elastic forces of a spring 13 and the elastomer 23 and, therefore, there is no possibility such that the slide part 17 is separated from the body part 12 at all. As a result, a current flows to a probe contact always stably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a probe contact for inspecting printed wiring boards (bare boards, in-circuits, etc.) for checking electrical circuit breaks, sheets, etc. It is something.

[Prior art and its problems] A probe contact used for testing circuit continuity of a printed circuit board, as shown in FIG. A body part 2 fitted into the socket 8, and a spring 3 attached to this body part 2.
When the tip 8 of the plunger contact 4 is pressed against the surface to be measured 5 of the printed circuit board, the plunger contact 4 is attached relative to the body 2. It is configured to be movable.

Thus, the tip 8 comes into contact with the surface to be measured 5 perpendicularly,
There is not much problem if spring 3 is pressed straight, but
If the tip comes into contact with the surface to be measured at an angle, or if an uneven force is applied to the spring for some reason, the body 2 and the sliding part 7 of the plunger contact 4 will momentarily As a result, the current stops flowing momentarily,
This is an obstacle to continuity testing. This is because when performing a circuit continuity test on a printed circuit board, current must always flow normally through the probe contact itself. In particular, as the need for more precise testing has increased recently, there has been a strong demand for probe contacts that do not have these drawbacks.

``Object of the Invention'' The present invention has been made in view of the above-mentioned circumstances, and aims to enable stable contact between the sliding part and the body of a plunger contact, thereby dramatically improving test accuracy. The purpose is to provide improved probe contact.

In order to achieve the above object, the present invention includes a plunger contact that is slidably attached to the body via a spring, and a rear part of the plunger contact. and a notch provided at the end to provide springiness, and the springiness allows the plunger contact to
It is characterized in that the body part and the plunger contact slide while being in elastic contact, so that the body part and the plunger contact can always be in reliable contact with each other.

"Embodiments" Below, preferred embodiments of the invention will be described with reference to the drawings.

As shown in FIG. 1, the plunger contact 14 is
A tip portion 16 that contacts the surface to be measured 19, a sliding portion 17 that slides on the body portion 12, a connecting portion 20 that connects the tip portion 1B and the sliding portion 17, and a connecting portion 20 formed at the tip of the sliding portion 17. Notch 2
2, and an elastic body 23 such as rubber that is fitted and fixed to the bottom of the notch 22. This plunger contact 14 is mounted inside the body 12 via a spring 13. The sliding part 17 resists the force of the spring 13 and moves the body part 12.
The elastic body 2 is inserted into the body and slides inside the body 12.
3 and the elastic force of the spring fitted into the notch 22, the sliding portion 17 is always elastically pressed against the body portion 12.

In this way, the body 12 with the plunger contact 14 mounted thereon is fitted into the socket 18. socket 1
8 is welded or glued through a mounting plate 11, which is referred to as a test head of a printed circuit board inspection machine. Sho 1
In the figure, 24 is a terminal, and a lead wire is connected to this terminal by soldering or the like.

In the present invention, it goes without saying that the plunger contact 14 and the body 12 must be made of a conductive material.

FIG. 2 shows another embodiment of the present invention, in which two sliding parts 17 and 17' are connected by a small-diameter connecting part 20, a notch 22 is formed in the tip sliding part 17, In this embodiment, which shows an example in which a cut is made between the bottom of the notch 22 and the rear end sliding part 17', the spring 13 is fitted into the notch 22, so when the spring is pressed, the spring Due to the elastic force, the rear end sliding portion 17 is expanded and the body portion 12 is elastically pressed. Therefore, the sliding middle body part 12 and the plunger contact sliding part 1
Always make sure to make contact with 7.

FIG. 3 shows another embodiment of the invention.

The connecting part 20 is the second part except that it covers the rear end sliding part 17'.
The structure is similar to the embodiment shown in the figure.

In the embodiments shown in FIGS. 1 to 3 above, the notch 22 is formed at the center of the end surface of the sliding portion 17.
This is not necessarily necessary, but it may be formed on the side as shown in FIG.
2, the sliding part 17 is given spring properties, and the sliding part 17
The body portion 12 slides while being in elastic contact with the body portion 12. However, in this case, in order to maintain the elasticity for a long time,
It is preferable to attach an elastic body such as rubber to the notch 22.

FIG. 5 shows another embodiment of the present invention, in which the sliding part 17
is formed into a substantially conical shape with a notch 22 formed at the tip, and the conical tip is formed in a substantially horizontal shape facing outward, so that the probe contact sliding portion 17 and the spring 13 are completely brought into close contact with each other. The probe contact 14 and the body portion 12 are configured to be energized via a spring 13.

In the above embodiment, the lower end of the spring 13 is fixed to the body part 12 by /\\bolding, so the sliding part 17 and the body part 12 are in complete contact with each other through the spring 13. Poor conduction between W4 between the sliding portion 14 and the body portion 12 is effectively prevented.

"Operation" Next, the operation of the present invention configured as described above will be explained with reference to FIG.

First, the tip 1B of the plunger contact is brought into contact with the solder surface 19 of the printed circuit board 18. At this time, even if a strong lateral force is applied to the sliding part 17, the sliding part g617 and the body part 12 will move due to the elastic force of the spring 13 and the elastic body 23.
Since the sliding part 17 and the body part 1 are in elastic contact so that they can freely slide,
There is no possibility that the probe contacts will separate from each other, so a stable current will always flow through the probe contacts.

"Effects of the Invention" As described above, according to the present invention, elastic force is imparted to the sliding part by forming a notch in the sliding part, so that the sliding part and the body are in elastic contact. Since the probe contacts are in contact with each other and therefore do not normally separate, a stable current flows through the probe contacts, dramatically improving the accuracy of testing printed wiring boards.

[Brief explanation of the drawing]

1 to 5 are cross-sectional views showing embodiments of the present invention, and FIG. 6 is a cross-sectional view showing a conventional probe contact. In the figure. DESCRIPTION OF SYMBOLS 12...Body part, 13...Spring, 17...Sliding part, 14...Plunger contact, 22...Notch part, 23...Rubber-like elastic body Patent Applicant Limited Company Kiyota Seisakusho Co., Ltd. Yama-
Seiko ゜・t'、Wa Vl、、、、i Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6

Claims (3)

[Claims] (1) A plunger contact that is slidably attached to the body via a spring, and a notch formed at the rear end of the plunger contact that imparts spring properties; The probe contact is characterized in that the plunger contact and the body portion slide while being in elastic contact with each other. (2) The probe contact according to claim 1, wherein the tip of the spring is fitted into the notch, and the spring is pressed to apply a force in a direction to expand the notch. (3) The probe according to claim 1, wherein an elastic body such as rubber is fitted into the notch, and the elastic force of the elastic body applies a force in the direction of expanding the notch. contact.