JP2977467B2 - Jig for circuit board inspection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for circuit board inspection through electrical connection between each pin terminal of a socket mounted on a board to be inspected and an inspection circuit of a circuit board inspection apparatus.

[0002]

2. Description of the Related Art A burn-in board is one of the test boards for semiconductor chips. In order to test as many chips as possible on a single board, several tens or more than one hundred IC sockets of the same standard are arranged vertically and horizontally. Has been implemented. In general, from the aspect of inspection using a burn-in board, each I
The elements connected to each pin of the C socket are all the same, and the circuit structure is extremely simple. However, the shipment inspection of the burn-in board requires a circuit connected to all the pins of the IC socket mounted on the burn-in board. Checks have to be made, which is extremely complicated, and much of the manufacturing period is devoted to the inspection for shipping. Moreover, today, semiconductor chips (LSI) having hundreds of pins continue to be present, and the present situation is such that it cannot be processed by manual inspection. Thus, such an inspection has been performed by an inspection apparatus using a computer as disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 5-34647, whereby the inspection time has been greatly reduced.

[0003]

However, in the conventional inspection apparatus, since the connection between the IC socket and the probe is made by a person, the contact state becomes uneven due to the shaking of the hand during the inspection, and the adhesion to the pin terminal occurs. Due to the presence of the oxide film, not only the frequency of occurrence of errors due to poor contact is extremely high, but also the probe and the pins of the IC socket may be deformed when force is applied to an operator holding the probe. In addition, the introduction of an automatic inspection device that employs automatic insertion of a probe was introduced, so that even though it was inserted into an IC socket with even force, it was necessary to obtain a good track record with few contact failures due to the structure of the jig. Not reached.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a jig for inspecting a circuit board, which is suitable for automation of an inspection apparatus and has less contact failure.

[0005]

According to the present invention, there is provided a jig for inspecting a circuit board, comprising: a bush having a mortar-shaped bearing hole fixed to a movable base of an automatic insertion device and vertically penetrating; A centripetal body having a tapered portion extending upward and having horizontal vibration generating means attached thereto. The centripetal body is suspended in a state of being urged downward on the periphery of the bearing hole, and the centripetal body is horizontally moved with respect to the bush. Either a cam groove or a cam follower that slides along the cam groove is provided on the centripetal body to restrict rotation in the direction, and the other is provided on the bush. A probe, which is arranged in the same manner as described above and electrically connects each contact terminal to the circuit board inspection circuit, is detachably supported. The centripetal body is configured such that horizontal vibration generating means formed by fixing an eccentric weight to a rotating shaft of a motor and a centripetal shaft having a tapered portion that expands to fit into a bearing hole of the bush cannot be detached via a bearing. And a coaxial connection, or horizontal vibration generating means that vibrates at a non-resonant frequency with respect to the natural vibration of the centripetal body urged downward may be used.

[0006]

By providing a mortar-shaped bearing hole in the bush and forming a tapered portion on the centripetal body urged downward,
In the steady state, the centripetal structure always points directly below the center of the bearing hole, and the direction of the probe is almost fixed by the relationship between the cam groove and the cam follower. In addition, it corrects minute displacement when mounting the probe to the socket by generating horizontal vibration, removes foreign matter and oxide film on the surface of the pin terminal of the socket, and fixes it to the movable base of the automatic insertion device. The vibration of the automatic insertion device itself is reduced by causing the centripetal body which is substantially free from the bush to self-oscillate. Furthermore, the vibration of the centripetal body is stabilized by selecting a non-resonant frequency with respect to the natural vibration of the centripetal body biased downward as the vibration frequency of the horizontal vibration generating means.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a jig for circuit board inspection according to the present invention will be described in detail with reference to the drawings. In the present embodiment, a centripetal body 5 that supports a probe 9 to be mounted on an IC socket mounted on a circuit board to be inspected, a bush 2 that supports the centripetal body 5 in a state where a movable range is limited, It is composed of a frame 15 interposed for fixing the bush 2 to the movable base of the automatic insertion device.

The frame 15 serves as a base for supporting the components of the jig.
In order to automatically insert the probe 9 into the C socket, the probe 9 is directly fixed to a movable base that moves mechanically vertically and horizontally or vertically. The frame 15 of the present embodiment is a metal flat plate provided with a vertically extending support hole 16, and a reinforcing plate 17 is suspended from one side of the flat plate. On the other hand, the bush 2 has a mortar-shaped bearing hole 1 at the center, and is formed by integrally surrounding a flange portion 18 at the center of the peripheral surface. The lower surface of the flange portion 18 is bored perpendicularly to the lower surface of the flange portion 18 so that the lower surface of the flange portion 18 can function as a support surface when fixing the bush 2 to the frame 15.

The frame 15 and the bush 2
The lower part of the bush 2 is fitted in the lower part and the upper surface of the frame 15 and the lower surface of the flange part 18 are screwed in a state of being in close contact. A pair of bearings 19, 19 are provided on the upper surface of the flange 18.
Are fixed symmetrically to the bearing hole 1 of the bush 2, and the cam followers 7, 7 are rotatably supported on the bearings 19, 19 by bolts pointing in the radial direction with respect to the bearing hole 1 of the bush. .

The centripetal body 5 comprises the horizontal vibration transmitting means 4, a centripetal shaft 13 and a connecting member 20.

The centrifugal shaft 13 has a rod-like rotating body for the most part, has a columnar shape with the smallest cross-sectional area from the lower part to the middle part, and has a tapered part 3 which expands upward from the middle part to the upper part. Have been. A ring-shaped cam portion 21 for restricting rotation of the centripetal shaft 13 is integrally formed on the upper portion of the tapered portion 3, and a concave portion 22 opening upward is provided at a central portion thereof, and a vertical portion is provided on an edge portion thereof. A pair of penetrating cam grooves 6, 6 are formed symmetrically with respect to the recess 22 with a width substantially equal to the diameter of the cam followers 7, 7. It is desirable to set the width and depth of each of the cam grooves 6, 6 to such an extent that an appropriate clearance is generated when the cam followers 7, 7 slide. With moderate clearance,
For example, when the probe 9 having the contact terminals 8 arranged in the same manner as the pin arrangement of the IC or the like is used, the deflection substantially equal to the pin pitch of the IC or the like is caused in the vertical and horizontal directions or the rotation direction at the contact terminals 8 of the probe 9. To the extent that it occurs.

The connecting member 20 is detachably interposed between the lower portion of the centripetal shaft 13 and the probe 9 and has a role of transmitting the motion of the centripetal shaft 13 determined by the shape of the bush 2 and the tapered portion 3 to the probe 9. And a spring 2 for urging the centripetal body 5 downward against the bush 2.
3 points of emphasis. The connecting member 20 has a columnar shape with a cross-sectional size substantially equal to the outer diameter of the spring 23 to be mounted, and has an annular notch at one end of the connecting member 20 at which the one of the spring 23 fits. At the center of the upper surface of the connecting member 20, an upper hole 24 into which the lower part of the centripetal shaft 13 fits is formed. At the center of the lower surface, a lower hole 26 into which the rod 25 of the probe 9 fits is formed. At the lower part, screw holes communicating with the upper and lower holes 24 and 26 are formed horizontally, and are connected to the centripetal shaft 13 and the probe 9 with set screws screwed into the screw holes.

The fulcrum of the spring 23 for the point of force is the lower surface of the frame 15. On the lower surface of the frame 15,
A notch or the like into which one end of the spring 23 fits is not provided, but the diameter of the lower part of the bush 2 that fits into the support hole 16 is set substantially equal to the inner diameter of the spring 23, and the frame 1
If the lower end of the bush 2 is made to protrude from the lower surface of the frame 15 in a state where the upper surface of the flange 5 and the lower surface of the flange portion 18 are in close contact with each other, the projecting portion and the spring 23 are fitted, and the position of the spring 23 is stable. Will be done.

In the present invention, the main body of the centripetal body 5 described above is further provided with a horizontal vibration generating means 4. The horizontal vibration generating means 4 of the present embodiment is obtained by mounting a load 27 having an uneven balance to the rotating shaft 11 of the motor 10. The motor 10 is connected to the cam portion 2 of the centrifugal shaft 13.
Four pillars 28 are erected on the upper surface of 1, and the rotating shaft 11 faces downward on a seat plate 29 installed on the upper end thereof, and the extension of the rotating shaft 11 coincides with the central axis of the centripetal shaft 13. To fix it.

The load 27 is provided with a disk-shaped eccentric weight 12 having a flange portion 31 provided in a disk shape around an intermediate portion of a connecting shaft 30 which rotates together with the rotating shaft 11 of the motor 10, and a partially cut-out portion of the flange portion 31. Is screwed. The upper and lower portions of the connecting shaft 30 are each formed with a step smaller in diameter than the intermediate portion, the upper portion is connected to a connecting member 32 connected to the rotating shaft 11 of the motor 10, and the lower portion is provided with two rows of bearings 14, The bearing 14 is clamped by a stepped portion on which the intermediate portion 14 is mounted and the boundary between the intermediate portion and the details, and a stop plate 33 screwed to the lower end surface of the connecting shaft 30 so that there is no play in the rotation of the bearings 14. .

The lower portion of the connecting shaft 30 on which the bearings 14 are mounted is inserted into a concave portion 22 formed at the center of the upper surface of the cam portion 21 of the centripetal shaft 13. Recess 22
The upper part is a two-step hole whose upper part is wide and the lower part is narrow, and the center of the upper part and the lower part is located on the extension of the rotating shaft 11 of the motor 10. The small-diameter portion of the recess 22 is a housing portion for the screw to which the stop plate 33 is fixed, and the large-diameter portion is a portion for housing the bearings 14. Therefore, the diameter of the large diameter portion is set equal to the outer diameter of the bearing 14, and the depth is set slightly larger than the thickness of the bearing 14 for two rows. By screwing a ring-shaped lid member 34 on the upper surface of the cam portion 21, the penetration portion 3 protruding along the edge of the hole in the center of the lid member 14 is formed.
5 is a bearing 1 mounted on the lower part of the connecting shaft 30
Since the upper edge of the bearing shaft 4 is pressed and the lower edge of the bearing 14 is in contact with the step of the inner wall of the concave portion 22, the lower portion of the connecting shaft 30 inserted into the concave portion 22 cannot be removed.

Thus, the horizontal vibration generating means 4, the centripetal shaft 13 and the connecting member 20 are integrally suspended from the bearing hole 1 of the bush 2, and the state of the spring 23 is maintained by the restoring force of the spring 23.

An appropriate spring constant of the spring 23 is as follows:
Although it depends on the weight balance between the upper and lower portions of the centripetal body 5 and the like, when selecting the spring constant of the spring 23 to be used, the upper limit at which the pin terminal of the socket is not damaged by the pressure applied when the spring 23 is compressed and contracted. It is necessary to set the lower limit of the range in which the centripetal body 5 can be instantaneously returned to the home position even if the centripetal body 5 does not move unnecessarily due to the movement of the jig. Note that the surfaces of the pin terminals provided in the socket are not always located at the same height, and that some variations always occur. Therefore, in order to bring the contact terminals 8 into contact with all the pin terminals, the spring 23 is required. Must have a higher elasticity than either the pin terminal of the socket or the contact terminal 8 of the probe 9. Rubber or elastic resin is one that can provide the same effect as the spring 23. Various selections are possible, such as using an elastic member formed by molding them into a cylindrical shape.

Also, the vibration frequency (1
When a value that periodically applies a force to the centripetal body 5 at the same frequency as the natural vibration is set as the number of rotations of the motor per second), the vibration of the horizontal vibration generating means 4 and the vibration of the centripetal body 5 are resonantly amplified. Since it may be difficult to make a normal contact, the rotation of the motor 10 may be adjusted to generate vibration at a non-resonant frequency, or the spring constant, the length of the centripetal shaft 13, and the weight of the eccentric weight 12 may be reduced. It is desirable to cause natural vibration that does not cause resonance with the vibration frequency by changing it.

The present embodiment is constructed as described above, and the probe 9 is suitably mounted on the IC socket mounted on the circuit board to be inspected by the jig fixed to the movable base of the automatic insertion device. Inspection of the circuits connected to the terminals is performed sequentially. Since the probe 9 is mounted on the IC socket while generating micro-vibration by the horizontal vibration generating means 4, the contact terminal is moved to the position of the pin terminal even if a slight displacement occurs in the vertical and horizontal directions or in the rotation direction in the mounting state of the IC socket. 8 is suitably guided, and when they come into contact with each other, they also have an effect of peeling off foreign matter and an oxide film. When a predetermined time elapses after the two have come into contact with each other, the vibration stops, and the elasticity of the urging member ensures that the pin terminals and the contact terminals 8 are in contact with each other, and that the state is maintained.

The horizontal vibration generating means 4 and the centripetal shaft 1
The high-quality bearings are formed at both ends of the rotating load 27 by interposing the bearings 14 securely fixed between the bearing 3 and the rotating load 27, thereby preventing the load 27 from rotating and oscillating and smoothing the rotation, thereby generating horizontal vibration. Uniform vibration of the integrated centripetal body 5 including the means 4 is generated only by the movement of the center of gravity.

[0022]

As described above, the use of the jig for circuit board inspection according to the present invention stabilizes the position and posture of the probe with respect to the movable base of the automatic insertion device in a steady state, and further increases the position and posture by applying horizontal vibration. Fine-tuned. At the same time, the removal of foreign matter on the contact surface of the pin terminals greatly reduces contact failures, and reduces the frequency of re-inspection, thereby contributing to a shorter inspection time and a shorter delivery time. . In addition, by using probes that connect to various sockets and connectors, it can be used for inspection of various circuit boards.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a jig for circuit board inspection according to the present invention.

FIG. 2 is a side view of the jig.

FIG. 3 is a plan view of a bush used for the jig.

FIG. 4 is a sectional view of the bush taken along the line AA.

FIG. 5 is a plan view of an eccentric weight used for the jig.

FIG. 6 is a cross-sectional view of the eccentric weight taken along the line BB.

FIG. 7 is a plan view seen from below a probe used for the jig.

FIG. 8 is a sectional view of a main part of the probe.

FIG. 9 is a perspective view showing an embodiment of an inspection using a circuit board inspection jig according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bearing hole 2 Bush 3 Taper part 4 Horizontal vibration generating means 5 Centripetal body 6 Cam groove 7 Cam follower 8 Contact terminal 9 Probe 10 Motor 11 Rotation axis 12 Eccentric weight 13 Centripetal shaft 14 Bearing

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Inoue Tateyama Machine Co., Ltd., No. 30, Oyamacho, Kamishinkawa-gun, Toyama Prefecture (56) References JP-A-5-264654 (JP, A) JP-A-3- 17574 (JP, A) Fully open 1986-197577 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01R 31/26 G01R 31/02 G01R 1/06-1/073

Claims (3)

(57) [Claims] A bush (2) fixed to a movable base of an automatic insertion device and having a mortar-shaped bearing hole (1) penetrating vertically, and an upwardly expanding tapered portion (3) fitted in the bearing hole (1). And a centripetal body (5) provided with a horizontal vibration generating means (4). The centripetal body (5) is suspended in a state of being urged downward on the periphery of the bearing hole (1), and a bush is provided. Either a cam groove (6) or a cam follower (7) sliding along the cam groove (6) is provided on the centripetal body (5) to limit the horizontal rotation of the centripetal body (5) relative to (2), and the other is a bush. A contact terminal (8) is provided at the tip of the centripetal body (5) in the same manner as the pin terminals of the predetermined socket, and each contact terminal (8) is electrically connected to the circuit board inspection circuit. The connected probe (9) is detachably supported. Jig for circuit board inspection. 2. The centripetal body (5) includes a motor (10).
A horizontal vibration generating means (4) formed by fixing an eccentric weight (12) to a rotating shaft (11) of the above, and a tapered portion (3) which expands to fit into a bearing hole (1) of the bush (2). 2. The jig for circuit board inspection according to claim 1, wherein said jig is irremovably and coaxially connected to a centering shaft (13) having a bearing. 3. The circuit board according to claim 1, wherein a horizontal vibration generating means (4) vibrating at a non-resonant frequency with respect to a natural vibration of the centripetal body (5) biased downward is used. Jig for inspection.