JPH1164429A - Probe unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform installation in a narrow space and to easily perform the positioning control of a pin probe. SOLUTION: A pin probe 16 is mounted to a piston 14 inside a cylinder 12. Then, a tube 18 housing a shape memory element 20 is connected to the rear end of the cylinder 12, the shape memory element 20 is arranged along the lengthwise direction of the housing tube 18, the tip part of the shape memory element 20 is connected to the rear end of the piston 14 and further, the rear end of the shape memory element 20 is fixed near the rear end of the housing tube 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe unit used for a circuit board inspection apparatus such as an XY type in-circuit tester.

[0002]

2. Description of the Related Art Conventionally, a mounting substrate, that is, a printed circuit board on which a large number of electronic components are soldered, uses an in-circuit tester to appropriately bring the tip of a pin probe into contact with a required measurement point on the board. The presence or absence of components is electrically detected, or the characteristic value of each component is electrically measured to determine the quality of the board. In particular, in the XY type in-circuit tester, the X-ray is placed on a measuring table on which the substrate to be inspected is mounted and fixed.
A Y-unit is installed, and a Z-axis unit movable in the Y-axis direction is provided on the arm movable in the X-axis direction.
The axis unit is equipped with an actuator and the pin probe is
It is movably supported in the axial direction. At the time of inspection, the XY unit is controlled, and the pin probe is appropriately moved in the X-axis, Y-axis, and Z-axis directions from above the substrate, and sequentially contacts predetermined measurement points. Therefore, the XY type in-circuit tester is suitable for inspection of a circuit board of a large variety of small production. As the actuator, a timing belt type in which a probe is driven by a timing belt, a crank type in which a probe is driven by a crank, an air cylinder type in which a probe is driven by an air cylinder, and the like are used.

[0003]

However, in such a timing belt type or crank type actuator, the pin probe is guided together with the timing belt and the crank in order to ensure the linear movement of the pin probe in the Z-axis direction. A guide or the like is required, and the unit becomes large. However, since the pin probe is driven by the timing belt or the crank, the positioning control of the pin probe in the Z-axis direction becomes easy. In this regard, in the air cylinder type, the unit is small because the cylinder is a guide for guiding the movement of the pin probe. However, since air is the driving source,
Responsiveness deteriorates due to the compression and expansion of air, and it becomes difficult to control the positioning of the pin probe in the Z-axis direction.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and it is an object of the present invention to provide a probe unit which can be installed in a narrow space and can easily control the positioning of a pin probe. And

Another object of the present invention is to provide a probe unit which can be more easily installed in a narrow space. Third, it is another object of the present invention to provide a multi-probe unit that can cope with a fine pitch of an IC or the like.

[0006]

In order to achieve the above object, in a probe unit according to the first object of the present invention, a pin probe is mounted on a piston in a cylinder. Then, a pipe containing the shape memory element is connected to the rear end of the cylinder, and the shape memory element is arranged along the length direction of the storage pipe, and the front end of the shape memory element is connected to the rear end of the piston. And the rear end of the shape memory element is fixed near the rear end of the storage tube.

In the probe unit corresponding to the second object, a storage tube and a shape memory element having flexibility are used. In the multiple probe unit corresponding to the third object, a plurality of probe units are arranged and all cylinders are integrally connected.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front view showing the structure of one embodiment of a probe unit to which the present invention is applied. In the figure, 10 is a probe unit, 12 is a cylindrical cylinder, 14 is a piston housed in the cylinder 12, and 16 is a pin probe mounted on the piston 14. The tip of the pin probe 16 is made to protrude from the tip of the cylinder 12 even when retracted.

Reference numeral 18 denotes an elongated circular tube connected to the rear end of the cylinder 12;
It is a shape memory element arranged along the length direction of the storage tube 18. The storage pipe 18 is a flexible pipe made of plastic or the like, and its outer diameter is made substantially equal to the outer diameter of the cylinder 12. The shape memory element 20 is formed by processing a shape memory alloy or the like into a coil spring shape so as to impart flexibility.
Then, the front end of the shape memory element 20 is connected to the rear end of the piston 14, and the rear end of the shape memory element 20 is connected to the storage tube 18.
Is fixed to the support member 22 installed near the receding portion. Therefore, the outer diameter of the actuator is substantially equal to the outer diameter of the cylinder 12 and becomes elongated, and the probe unit 10 becomes compact.

As described above, when the shape memory element 20 is used for the probe unit 10, an electric current is supplied to or cut off from the shape memory element 20, or a high-temperature fluid such as oil is put into or taken out of the storage tube 18. The shape memory element 20 is heated and cooled by pressing or the like, and the shape memory element 20 is contracted as shown on the left side in FIG. It can be extended by the distance L. Therefore, the displacement of the tip of the shape memory element 20 is controlled by the piston 14 guided by the cylinder 12.
When the piston 14 is linearly moved, the pin probe 16 attached to the piston 14 linearly moves. When the shape memory element 20 is processed into a coil spring shape and used, the displacement of expansion and contraction increases, so that the stroke of the pin probe 16 naturally increases.

[0011] Such a probe unit 10 is XY
When installed in the Z-axis unit of the system in-circuit tester, if the storage tube 18 and the shape memory element 20 have flexibility, they can be appropriately bent and their shapes can be freely changed to some extent. it can. Therefore, as compared with the case where the storage tube or the like has no flexibility, even if the space is narrower, the probe unit 10 can be easily installed. In addition, since the pin probe 16 is driven by the expansion and contraction of the shape memory element 20, the positioning control of the pin probe 16 in the Z-axis direction can be easily performed.

FIG. 3 shows a multi-probe unit 26 in which a plurality of such probe units 10, for example, five, are arranged and all the cylinders 12 are integrally connected by using a base member 24. And this multi-probe unit 26
Since the probe units 10 are elongated and compact, the pins of the pin probes 16 can be arranged in a straight line at equal intervals during manufacture so that their pitches can be made finer. Therefore, the multiple probe unit 26 is
When installed and used on the Z-axis unit of the system in-circuit tester, it can be used for fine pitching of electronic components, etc.
It is possible to inspect pins (leads) and patterns of ICs (integrated circuits) and the like whose pitches are becoming finer in recent years. In addition, since each pin probe 16 can be independently and individually moved, a necessary probe may be selected and used.

[0013]

According to the present invention described above, claim 1
In the described invention, since the cylinder accommodating the shape memory element is connected to the cylinder and the actuator is formed to be elongated, the whole becomes compact and can be installed even in a narrow space.
Further, since the pin probe is driven by a change in the shape of the shape memory element, positioning control is easily performed.

According to the second aspect of the present invention, the shape of the storage tube and the shape memory element can be changed to some extent freely by appropriately bending the storage tube and the shape memory element. Therefore, installation in a narrow space becomes easier. According to the third aspect of the present invention, since each probe unit is elongated and compact, it can be provided on the base member to make the pitch of each pin probe finer. Therefore, it is possible to cope with a fine pitch of an IC or the like.

[Brief description of the drawings]

FIG. 1 is a front view showing one embodiment of a probe unit to which the present invention is applied.

FIG. 2 is a front view showing each state of an actuator provided in the probe unit when a shape memory element is contracted and extended.

FIG. 3 is a front view showing an embodiment of a multi-probe unit including five probe units.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Probe unit 12 ... Cylinder 14 ... Piston 16 ... Pin probe 18 ... Storage tube 20 ... Shape memory element 22 ... Support member 24 ... Base member 26
… Multiple probe units

Claims (3)

[Claims] 1. A probe unit comprising a piston in a cylinder and a pin probe mounted thereon, wherein a pipe containing a shape memory element is connected to a rear end of the cylinder, and the shape memory element is connected to the length direction of the storage pipe. A probe unit, wherein the tip end of the shape memory element is connected to the rear end of the piston, and the rear end of the shape memory element is fixed near the rear end of the storage tube. . 2. The probe unit according to claim 1, wherein the storage tube and the shape memory element have flexibility. 3. A multi-probe unit, wherein a plurality of the probe units according to claim 1 or 2 are arranged and all cylinders are integrally connected.