JPH0628699Y2 - Probe contact - Google Patents

Description

[Detailed description of the device]

[0001]

[Industrial application] This invention is for the disconnection of an electric circuit of a printed wiring board (bare board, in-circuit, etc.),
The present invention relates to a probe contact for inspecting a printed circuit board for inspecting a short circuit or the like.

[0002]

2. Description of the Related Art As shown in FIG. 5, a probe contact used for testing circuit continuity of a printed circuit board includes a socket 8 fixedly mounted on a mounting plate 1 of a printed circuit board inspection machine, and the socket 8. A body portion 2 fitted to 8;
The plunger contact 4 is mounted on the body portion 2 via a spring 3 or the like.
The plunger contact 4 is configured to be movable relative to the body portion 2 when the tip portion 6 of the is pressed against the measured surface 5 of the printed circuit board.

Although there is no problem when the tip portion 6 vertically contacts the surface 5 to be measured and the spring 3 is pressed straight, the tip portion tilts and contacts the surface 5 to be measured. If the spring is in a non-uniform force due to some reason or for some reason, the body 2 and the plunger contact 4 are
The sliding portion 7 of the above is momentarily separated, and as a result, the current stops flowing instantaneously, which is an obstacle to the continuity test. This is because when conducting a circuit continuity test or the like on a printed circuit board, a current must always flow normally through the probe contact itself. In particular, recently, the need for more precise tests is increasing, and thus there is a strong demand for probe contacts free from such defects.

In order to solve such a problem, as shown in FIG. 6, the lower surface of the sliding portion 7 of the plunger contact 4 is formed into an inclined surface, and a small ball 9 is provided between the inclined surface and the spring 3. An intervening probe contact has been proposed by a US company and has already been patented. In this probe contact, since the slant surface of the sliding portion 7 and the small ball 9 contact each other, the sliding portion 7 receives a force in the left direction and the small ball 9 receives a force in the right direction in FIG. Therefore, contact is ensured.

Recently, however, the pitch spacing of the printed circuit board to be inspected has become very narrow, so that there is a strong demand for a contact probe in which the tip of the center conductor does not move from the center as much as possible. This is because if the tip of the center conductor moves even a little, the tip of the center conductor may hit an unintended surface to be measured. In order to prevent the tip of the center conductor from moving as much as possible, it is necessary to make the center conductor as thin as possible and to minimize the clearance between the center conductor and the sleeve.

However, in the conventional contact probe shown in FIG. 6, the small sphere currently available in Japan is 0.5 m.
Since it is m or more, there is a problem that the central conductor cannot be 0.7 mm or less. Not only that, but the contact between the small balls 9 and the sliding portion 7 is point contact, which is also unsatisfactory in terms of obtaining reliable contact.

[0007]

[Problems to be Solved by the Invention] This invention intends to solve all of the above-mentioned conventional problems at once.
It is an object of the present invention to provide a contact probe that enables a plunger contact and a contact to be in stable contact with each other, and in which the probe contact itself can be formed to have an extremely small diameter.

[0008]

SUMMARY OF THE INVENTION According to the structure of the present invention which meets the above-mentioned object, a plunger contact, a body portion which slidably holds a sliding portion of the plunger contact, and a rear portion of the plunger contact are connected. Small diameter rod installed,
A contactor that is closely fitted to the inner and lower ends of the body and slidably fits and holds the rod, and cuts the tip of the fitted contactor or the fitting portion of the small diameter rod. The tip of the rod is slidably fitted and held by the contactor.

Since the contact probe generally has a poor contact when formed thinly, it has not been possible to form the contact probe too thinly from this point, according to the present invention.
A small-diameter rod is continuously provided at the rear portion of the plunger contact, and the rod is fitted and supported to ensure contact, and as a result, the contact probe can be formed to have an extremely small diameter. It is what Specifically, according to the present invention, it is possible to form the contact probe with a small diameter of 0.2 mm to 0.3 mm.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
It is sectional drawing of the small diameter rod and contactor of FIG. The plunger contact 14 includes 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 16 and the sliding portion 17, and a sliding portion. Small diameter rod 2 connected to the portion 17 via a small projection 21
2 and.

The sliding portion 17 is fitted in the body portion 12 against the force of the spring 13 and slides in the body portion 12. The tip of the small-diameter rod 22 has a contactor 2 attached to the lower end of the body 12.
4 is fitted in the opening 25. Since the tip fitting portion of the contactor 24 is cut and curved in a taper manner, the function of a spring is imparted and the rod is elastically held. As described above, the body 12 having the plunger contact 14 and the contact 24 mounted therein is fitted into the socket 27. Socket 2
7 is welded or adhered through a mounting plate 28 called a test head of the printed circuit board inspection machine.
Reference numeral 26 in the drawing is a terminal, and a lead wire is connected to this terminal by soldering or the like.

In the present invention, it is needless to say that the plunger contact, the body, the socket and the contact need to be made of a conductive material. FIG. 3 shows another embodiment of the present invention, in which the tip 23 of the small diameter rod 22 is formed in two and the central part of the two is bulged outward to form a spring. It has a function and is elastically fitted to the contactor 24. In the present invention, since the contact and the rod are slidably and elastically fitted, not only a stable contact is obtained even when the rod moves up and down, but also a spring for sliding the rod is used. Since the frictional force between the rod and the contactor is much smaller than the force (about 1/10), the frictional force with respect to the vertical movement of the rod is almost the same as the conventional one.

[0013]

Next, the operation of the present invention constructed as above will be described. First, the tip end portion 16 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 contactor, since the contactor and the rod are elastically fitted, there is no possibility that the contactor 24 and the tip of the rod are separated from each other. Therefore, a stable current always flows through the probe contact. It has been confirmed by experiments that stable contact can be obtained even when the rod is moved up and down tens of thousands of times.

[0014]

As described above, according to the present invention, since the tip of the rod connected to the sliding portion and the contact are slidably fitted and held, the contact and the tip of the rod are Since the probe contacts do not separate from each other, a stable current always flows, so that the test accuracy of the printed wiring board is dramatically improved, and the probe contact can be configured with an extremely small diameter. It is possible to inspect at narrow pitch intervals.

[0015]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a contactor and a rod of FIG.

FIG. 3 is a cross-sectional view showing another embodiment of the present invention.

FIG. 4 is an enlarged view of the contactor and the rod of FIG.

FIG. 5 is a cross-sectional view showing a conventional probe contact.

FIG. 6 is a cross-sectional view showing another example of a conventional probe contact.

[Explanation of symbols]

 12 Body 14 Plunger Contact 22 Rod 24 Contactor

Claims (1)

[Scope of utility model registration request] 1. A body portion for slidably holding a plunger contact and a sliding portion of the plunger contact, a small-diameter rod connected to a rear portion of the plunger contact, and a close fit to an inner lower end of the body portion. And a contactor for slidably fitting and holding the rod, and the tip of the rod is fitted by cutting the tip of the contactor or the fitting portion of the small diameter rod. A probe contact, which is slidably fitted and held by the contactor.