JPH0146829B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an inspection device that performs electrical tests, inspections, etc. by bringing the tips of contact probes into contact with inspection points on circuit boards such as ICs and LSIs.

[Technical background of the invention and its problems] A coaxial movable contact in which a center conductor is provided in an insulated state inside an external conductor of a cylinder on a supporting plate that is movably provided facing a circuit board to be inspected. An inspection device for circuit boards, etc., which carries out electrical measurement and inspection by supporting a probe in a penetrating manner toward the circuit board and bringing the tip of the contact probe into contact with a test point on the circuit board by moving a support plate, is known, for example, from the Tokuko Showa Institute of Technology. It is known as described in Japanese Patent No. 58-175273.

Due to its coaxial structure, this type of coaxial movable contact probe has advantages such as good impedance matching, low signal leakage, and low signal level attenuation, and can perform electrically good measurements and inspections. can.

However, in conventional coaxial movable contact probes, the center conductor is the most prone to failure and damage.
When it is damaged and must be replaced, the replacement work cannot be performed unless other parts such as the outer conductor are also removed.

On the other hand, the conventional coaxial type movable contact probe has the disadvantage that the structure for mounting it on the support plate is relatively complicated, and it takes time and effort to attach and detach it.

[Purpose of the invention]

The present invention was created in view of the above problems, and its main purpose is to easily insert and remove only the center conductor of a coaxial movable contact probe, thereby allowing instant replacement. The goal is to be able to do this.

Another object of the present invention is to enable a coaxial movable contact probe to be reliably mounted on a support plate with a simple structure.

[Summary of the invention]

In order to achieve the main purpose of the present invention, an insulating tube having a through hole for inserting the center conductor in the center is fixed inside the outer conductor of the contact probe, and the center conductor has a cylindrical main body and a main body. It consists of a tip pin that is supported at the tip so that it can be freely retracted against the spring force,
The main body of the center conductor is frictionally inserted and supported in a removable manner into the through hole of the insulating cylinder, and means for positioning the main body of the center conductor into the through hole is further provided.

In addition, in order to easily attach the contact probe to the support plate, an outer cylinder is integrally fitted on the outside of the outer conductor of the contact probe, and a protrusion is provided on the outer circumferential surface of the outer cylinder, which is inserted through the support plate. The outer tube is inserted into the contact probe insertion hole in such a manner that the protruding portion is pressed into contact with the insertion hole.

[Embodiments of the invention]

This figure shows an embodiment of the apparatus for inspecting circuit boards and the like shown in FIG. 1. In the figure, reference numeral 1 denotes, for example, four guide posts provided in parallel, which are fixedly installed at the four corners of the inspection apparatus.

A support frame 2 for a circuit board or the like is fixed to the upper end of the guide post 1, and an IC circuit board B to be inspected is supported by this frame.

A support plate 3 serving as a contact probe mounting board is provided below the support frame 2 and is guided by the guide post 1 and moves up and down. A large number of coaxial movable contact probes P are supported on the support plate 3 in the vertical direction. Each probe P has a contact portion at its tip (upper end), and when the support plate 3 rises toward the circuit board B on the support frame 2, the tip of each probe P electrically contacts the circuit pattern on the bottom surface of the circuit board B. Measurements and inspections are now performed by contacting the Note that the support plate 3 may be fixed and the support frame 2 may be moved up and down.

A connector holding plate 4 is provided below the support plate 3 and moves up and down along the guide post 1 together with the support plate 3. A coaxial cable 5 leading to a measuring device (not shown) is attached to this holding plate 4. A connector 6 for electrically connecting each probe P is held therein.

Details of how the coaxial movable contact probe P is supported on the support plate 3 and details of the structure of the contact probe P are shown in FIG. In the figure, 10 is a center conductor of a coaxial movable contact probe P, and 11 is a cylindrical outer conductor provided coaxially around the outer periphery of the center conductor. An insulating tube 12 made of an electrically insulating material is fixed to the inner surface of the outer conductor 11. The insulating tube 12 has a center conductor insertion through hole 13 in its center, into which the center conductor 10 is inserted.

An outer cylinder 14 is integrally fitted on the outside of the outer conductor 11, and a protrusion 15 is formed on the outer peripheral surface of the outer cylinder 14. The outer cylinder 14 may be formed of a conductor such as a metal, or may be formed of a non-conductive synthetic resin or the like. The outer cylinder 14 has a protrusion 15 that is connected to the support plate 3.
The insertion hole 1 is pressed against the inner surface of the insertion hole 17.
7, and its insertion position is at the stepped portion 18.
is determined by the contact with the support plate 3.

There is a recessed part 1 inside the tip (upper end) of the outer cylinder 14.
9 is formed to form an annular space between the outer conductor 11 and the outer conductor 11, into which the large-diameter base 20a of the cylindrical conductor constituting the movable tip portion 20 of the outer conductor 11 is slidably inserted. has been done. The distal end movable portion 20 is pressed outward from behind by a coil spring 21, and its escape is prevented by an inwardly folded flange 22 at the distal end of the outer cylinder 14.

The center conductor 10 has a cylindrical main body 24 and a tip pin 25. A base 24a of the tip pin 24 is inserted into the main body 24 in a manner that prevents it from coming off, and a coil spring 27 in the main body holds the tip pin 24. is ball 26
They are being oppressed outwardly through the coil spring 27
The inner end of the main body 24 is received by a bead 28 that has been deformed toward the inside of the main body 24. Positioning of the through hole 13 of the main body 24 in the axial direction is performed by a positioning means 30. In the illustrated example, the positioning means 30 is formed as a flange, and when the center conductor 10 is inserted into the through hole 13 until the flange 30 hits the tip end surface of the insulating cylinder 12, the center conductor 1
0 positioning is done.

In order to prevent the center conductor 10 from easily slipping out of the through hole 13, the center conductor 10 is frictionally inserted into the through hole 13. As a means for generating frictional force, the through hole 13 is made somewhat larger than the center conductor 10, and the main body 24 of the center conductor 10 is slightly curved so that it bends linearly when inserted into the through hole 13. It is possible to do so. The main body 24 may be bent by plastically deforming the main body material in advance, or by incorporating the tip pin 25 into the main body 24 and then bending the main body. Moreover, instead of providing curvature, a protrusion is formed from the inside to the outside of the main body 24, which has no curvature, and this protrusion is brought into contact with the somewhat elastic insulating cylinder 12, thereby providing a friction retaining function. Good too.

Connector 6 (first
(Fig.), the proximal end 10 of the center conductor 10
A is opened as shown in FIG. 2, and a cut 3 is made at the base end of the outer conductor 11 as shown in FIG.
2 to give expansion elasticity to the base end of the outer conductor 11.

The details of the connection with the coaxial cable 5 by the connector 6 are as shown in FIG. coaxial cable 5
consists of a core wire 40, a mesh wire 41, an insulator 42 interposed between them, and an outer sheath 43.
The tip of the mesh wire 41 is folded back to the outside of the jacket 43 as shown, and a connecting plug fitting 44 of the connector is attached to it.

The connection plug fitting 44 is, as shown in FIG.
It includes a cylindrical attachment part 45 at the base end and a cylindrical large-diameter plug 46 at the distal end, and an annular groove 47 is formed outside the boundary between them. 49 is a small-diameter plug having a cutout 48 and a flange 50, and a protrusion 51 at the rear thereof is fitted into a hole at the center of an annular insulating member 52 fitted inside the large-diameter plug 46. At this time, the flange 50 is
It comes into contact with the tip surface of 2. The protrusion 51 has a cylindrical shape and has a hole 53.

The attachment part 45 of the connection plug fitting 44 having the above-mentioned configuration is attached to the fourth end of the coaxial cable 5.
It is covered as shown in the figure and attached to the coaxial cable 5 by crimping as shown at 54. Further, the tip of the coaxial cable core wire 40 is inserted into the hole 53 of the protrusion 51 and soldered as shown at 55.

The connection plug fitting 44 connected to the coaxial cable 5 in this way has its large diameter plug 46 fitted into the base end of the external conductor 11, and its small diameter plug 46.
9 is fitted into the base end 10a of the central conductor main body 24, thereby electrically connecting it to the contact probe P as shown in FIG. When fitted, the outer conductor 11 expands elastically due to the presence of the notch 32, and the inner bent portion 60 at its tip engages in the annular groove (FIG. 5) of the connection plug fitting 44 to prevent accidental escape. prevent. On the other hand, when fitting, the small diameter plug 49
is elastically contracted, and after connection, the small diameter plug 49 is pressed against the inner surface of the proximal end portion 10a of the central conductor main body 24. Thus, the outer conductor 11 connects to the mesh wire 41 of the coaxial cable 5 via the large diameter plug 46 and the attachment portion 45, and the center conductor 10 connects to the core wire 40 of the coaxial cable 5 via the small diameter plug 49 and the protrusion 51.
are connected to each.

The connector 6 constituted by the connection plug fitting 44 is attached to the connector holding plate 4 as shown in FIG. 1, and when the contact probe P is inserted into the insertion hole 17 of the support plate 3 to the predetermined position shown in FIG. ,
A contact probe P is connected to a connection plug fitting 44 located below it. Since the connector 6 has a structure as shown in the figure, it can be made to have the same diameter as the contact probe P, and since the connector 6 is not thicker than the contact probe P, the contact probe mounting density can be increased. can do.

The inspection device for circuit boards, etc. of the present invention configured as described above has the contact probe support plate 3 and the connector holding plate 4 relatively facing toward the circuit pattern of the circuit board B attached to the support frame 2. The tip pin 25 and the tip movable part 20 at the tips of the center conductor 10 and outer conductor 11 of each contact probe P touch the springs 27 and 21 at a predetermined point of the circuit pattern. They are pressed together by force and an electrical connection is established. Then, a signal is sent to a measuring device (not shown) via each contact probe P, connector 6, and coaxial cable 5, and a measurement test is performed.

At this time, since the space between the center conductor 10 and the outer conductor 11 of the contact probe is filled with the insulator 12, no change in impedance occurs, and the signal is sent from the measurement system to the object to be measured without disturbance in impedance. be able to. Moreover, since both the center conductor 10 and the outer conductor 11 have the tip pin 25 and the tip movable part 20 as movable contacts, the mounting density of the contact probes P is improved.

In addition, when the contact probe P has a small diameter, the outer cylinder 14 is omitted, and a protrusion is formed on a part of the outer conductor 11 from the inside to the outside, and the support plate 3 is inserted through this protrusion. The contact probe P may be attached to the support plate 3 by making frictional contact with the inner surface of the hole 17.

The side of the outer conductor 11 is the ground side, and the ground can also be connected from the outer conductor 11 via a conductor (not shown).

The principle of the present invention is based not only on a coaxial type movable contact probe P having a tip movable part 20 and a tip pin 25 at the distal end and whose base end is connected to a connector 6 as shown in FIG. As shown in FIG. 6, the proximal end of the contact probe P has the same structure as the distal end, and can also be applied to contact probes having a proximal movable portion 20' and a proximal pin 25'.

In this embodiment as well, the main body 24 of the center conductor 10 is
As described with reference to FIG. 2, it is removably inserted into the through hole 13 of the insulating cylinder 12, held by friction, and positioned by the positioning means 30. Further, the outer cylinder 14 is held within the insertion hole 17 of the support plate 3 by friction.

A contact probe of the type shown in FIG. 6 can be connected to the coaxial cable 5 by a connector 6' as shown in FIG. The coaxial cable 5 is the fourth
As in the case shown in the figure, it has a core wire 40, a mesh wire 41, an insulator 42, and an outer sheath 43, and the outer sheath 43 is peeled off at the tip side to expose the mesh wire 41. Exposed mesh wire 41
A cylindrical conductor 70 is attached to the outer periphery of the cylindrical conductor 70 by a constriction caulking portion 71. On the other hand, a core conductor 74 is fitted inside the cylindrical conductor 70 via an insulator 73, and the tip of the core wire 40 is inserted into the center hole of the core conductor 74, and the tip is soldered 75. Ru. Furthermore, the tip surfaces of the cylindrical conductor 70, core conductor 74, and insulator 73 are formed on the same plane. The cylindrical conductor 70 of the connector 6' as described above is press-fitted into the hole of the connector holding plate 4 and positioned by the stepped portion 76 thereof.

With such a configuration, the insertion hole 17 of the support plate 3
When the contact probe P is attached to the base conductor 74, the base pin 25' and the base movable part 20' compress the springs 27 and 21 behind them and retreat somewhat, as shown in FIG. and cylindrical conductor 70
An electrical connection is established by press-welding the surface of the

It is clear that this embodiment also has the same effects as the previously described embodiment.

Note that the present invention can be used not only for circuit boards but also for measuring and inspecting similar items, and the vertical direction of the contact probe P may be reversed.

〔Effect of the invention〕

As described above, in the present invention, the center conductor of the coaxial movable contact probe can be easily inserted and removed due to its unique structure.
It becomes easy to replace it in the event of failure or damage. In addition, positioning during insertion can be done instantaneously, and the device will not come out unnecessarily after insertion.

Further, according to the combined invention, the entire coaxial movable contact probe can be reliably and easily mounted on the support plate, and the probe can be structurally inexpensive.

[Brief explanation of drawings]

FIG. 1 is a front view of the inspection apparatus for circuit boards, etc. of the present invention, FIG. 2 is an enlarged longitudinal cross-sectional view of the coaxial movable contact probe portion of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line -- in FIG. , FIG. 4 is a vertical cross-sectional view showing details of the connector connected to the proximal end of the contact probe shown in FIG. 2, FIG. 5 is an enlarged vertical cross-sectional view of only the connecting plug fitting of the connector shown in FIG. 4, Fig. 6 is an enlarged vertical cross-sectional view similar to Fig. 2 showing a portion of a different type of coaxial movable contact probe, and Fig. 7 is a vertical cross-sectional view showing a connector connected to the proximal end of the contact probe of Fig. 6. It is a diagram. 2... Circuit board support frame, 3... Contact probe support plate, 4... Connector holding plate, 6, 6'...
... Connector, 5 ... Coaxial cable, B ... Circuit board, P ... Coaxial type movable contact probe, 10 ... Center conductor, 11 ... Outer conductor, 12 ... Insulation tube, 1
3...Through hole, 14...Outer cylinder, 19...Recessed part,
17... Insertion hole, 20... External conductor tip movable part,
20'... Base end movable part, 21... Coil spring, 2
4...Center conductor main body, 25...Tip pin, 25'
... Base end pin, 30 ... Positioning means, 40 ...
Core wire, 41...Mesh wire, 43...Outer cover, 44...Connection plug fitting, 45...Mounting part, 46...Large diameter plug, 49...Small diameter plug, 50...Protrusion part,
51... Insulating member, 54... Squeezing caulking part, 55
... Soldering part, 70 ... Cylindrical conductor, 73 ...
Insulator, 74... Core conductor, 75... Soldering part.

Claims (1)

[Scope of Claims] 1. A coaxial movable contact probe in which a central conductor is provided in an insulated state inside a cylindrical outer conductor on a supporting plate that is relatively movably provided facing a circuit board to be inspected. This is an inspection device for circuit boards, etc., in which the contact probe is supported in a penetrating state toward the circuit board, and the tip of the contact probe is brought into contact with the test point on the circuit board by moving the support plate relative to the circuit board to conduct electrical measurement tests. inside the outer conductor of the contact probe.
An insulating tube having a through hole for inserting the center conductor is fixed in the center, and the center conductor is composed of a cylindrical main body and a tip pin supported at the tip of the main body so as to be able to move back against the spring force. An inspection device for a circuit board, etc., which frictionally inserts and supports a conductor main body in a through-hole of an insulating cylinder so that it can be freely inserted and removed, and further includes means for inserting and positioning the center conductor main body into the through-hole. 2. The inspection device for circuit boards, etc. according to claim 1, wherein the insertion positioning means is constituted by a flange provided at the tip of the center conductor main body and abutting the end surface of the insulating tube. 3. A coaxial type movable contact probe, which has a central conductor insulated inside a cylindrical outer conductor, is mounted on a support plate that is relatively movable facing the circuit board to be inspected, and is placed toward the circuit board. An inspection device for circuit boards, etc. that performs electrical measurement and inspection by supporting the contact probe in a penetrating state and bringing the tip of the contact probe into contact with the test point on the circuit board by moving the support plate relative to the circuit board. inside the conductor,
An insulating tube having a through hole for inserting the center conductor is fixed in the center, and the center conductor is composed of a cylindrical main body and a tip pin supported at the tip of the main body so as to be able to move back against the spring force. The main body of the conductor is frictionally inserted and supported in a removable manner into the through-hole of the insulating tube, and means for positioning the center conductor body into the through-hole is further provided, and the outer tube is integrated on the outside of the outer conductor of the contact probe. A protrusion is provided on the outer peripheral surface of the outer cylinder, and the outer cylinder is inserted into a contact probe insertion hole provided through the support plate such that the protrusion is pressed into the insertion hole. Inspection equipment for circuit boards, etc. 4. Form the outer cylinder so that an annular space is formed between at least the distal end of the outer cylinder and the outer conductor inside the outer cylinder, and insert the proximal end of the movable tip part of the outer conductor into the annular space. An inspection device for circuit boards, etc., according to claim 3, wherein the distal end movable portion is freely retractable against a spring inserted into the annular space.