JPH06289057A - Probe for testing electric circuit - Google Patents

Abstract

PURPOSE:To improve an inspection accuracy and to improve durability by arranging probes at a fine pitch and making contact pressures to inspection points uniform. CONSTITUTION:Since protruding directions of bent parts 32 of probes 30 are aligned in a direction perpendicular to an arranging direction of the probes 30 and deforming directions of the parts 32 of the probes 30 are set to the same direction, no contact occurs between the probes 30, and hence a pitch between the adjacent probes 30 can be narrowed. Since stored states to be restored of the parts 32 are unified, protruding amounts of heads 31 of the probes 30 are uniformly brought into elastic contact with inspection points of surfaces to be inspected of a circuit board to be inspected. Since the heads 31 of the probes 30 are uniformly brought into elastic contact with the inspection points, a contact resistance can be uniformly held even in the case of inspection of an electronic component of an IC, etc., particularly to be operated by a very small current, and hence the reliability of an inspection accuracy can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric circuit test probe for inspecting the electric characteristics of a circuit board.

[0002]

2. Description of the Related Art In recent years, in order to quickly inspect a printed circuit board, IC parts, etc., probes are brought into contact with a large number of inspection points at the same time, and electric signals obtained through these probes are input to a tester. Electrical circuit test probes for inspecting electrical characteristics have become widespread.

1 and 2 show an example of a probe card for circuit inspection finely formed on a silicon wafer among such electric circuit test probes. A probe 51 having a plurality of elastic forces is arranged along the radial direction of the disc-shaped body 50. The tips of the respective probes 51 are gathered at the positions seen from the central hole 52 of the disk-shaped body 50.

In performing the inspection, when the disk-shaped body 50 descends toward the wafer circuit board 54 side, the tip of each probe 51 is moved by the elastic force of the probe 51 to the circuit of the wafer 53 on the wafer circuit board 54 in the downward arrow direction. Make contact with force. As a result, the circuit of the wafer 53 is electrically connected to the respective probes 51, so that the circuit test universal tester (not shown) conducts a continuity test.

However, in such a probe card, when the tips of the respective probes 51 are elastically contacted by the force in the downward arrow direction, the respective probes 51 bend and the respective tips are moved in the horizontal arrow direction. Slide. Therefore, not only is the circuit surface of the wafer 53 damaged,
It is necessary to match the measurement point (contact point) on the circuit surface of the wafer 53 when the tip portion is moved by sliding, and strict requirements are placed on the total accuracy.

As a solution to such a problem,
There is an electric circuit test probe in which a probe is elastically contacted with an inspection point on a printed circuit board or the like from a vertical direction.

That is, as shown in FIG. 3, the electric circuit test probe comprises an off-grid jig 1 and a universal pin board section 2. The off-grid jig 1 is provided with an upper plate 3, an intermediate plate 4 and a lower plate 5 made of an insulating material. The upper plate 3 and the intermediate plate 4 are arranged in close proximity to each other and in parallel with each other. The plates 5 are arranged in parallel with each other with a space therebetween.

Further, the upper plate 3 and the middle plate 4 are provided with an input side through hole 6 corresponding to an inspection point of a printed circuit board or the like, and the lower plate 5 corresponds to a fixing pin described later, for example, 2 .5
A large number of output-side through holes 7 arranged in a matrix with a pitch of 4 mm are formed. A large number of wire probes 8 are inserted into these input-side through holes 6 and output-side through holes 7, and these are fixed to the upper plate 3 by a conical contact head 8a formed on one end side. ing.

On the other hand, a large number of fixing pins 10 are planted on the universal pin board 9 made of an insulating material of the universal pin board portion 2. These fixed pins 10 are arranged in a matrix with a pitch of 2.54 mm, for example. The conical contact portion 8b on the other end side of the wire probe 8 is in contact with one end of these fixed pins 10.
The other end of the fixed pin 10 is connected to a circuit test universal tester (not shown) via a lead wire 11.

In such a structure, when the jig is pressed against a substrate to be inspected such as a printed circuit board during inspection, the pressing force is applied to the wire probe 8 between the intermediate plate 4 and the lower plate 5.
The contact head 8a is elastically deformed due to the buckling of the test piece, and its contact head 8a is in elastic contact with each inspection point of the board to be inspected.

[0011]

However, in the above-described conventional electric circuit test probe, the contact head 8a is elastically contacted with each inspection point on the substrate to be inspected by elastic deformation due to buckling of the wire probe 8. Because
Since the directions of elastic deformation of the wire probes 8 are different from each other, it is necessary to provide a space between the wire probes 8 to such an extent that they do not contact each other due to elastic deformation due to buckling, to prevent mutual interference. Therefore, it is impossible to narrow the pitch interval of the wire probes 8 to, for example, about 1.27 mm, and an IC having lead wires with a narrow pitch is provided.
There is a problem that it is impossible to inspect parts and the like.

Further, since the wire probes 8 are of the same length, the wire probe 8 is inserted into the wire through the input side through hole 6 and the output side through hole 7 depending on the positional deviation. The height of the contact head 8a of the probe 8 is different, and the elastic contact force of each contact head 8a with respect to each inspection point of the board to be inspected is varied, so the elastic contact force of each board to be inspected is different. However, there was a problem that the inspection point of the part with a large elastic contact force was damaged.

Further, since the elastic contact force of each contact head 8a with respect to each inspection point of the substrate to be inspected is varied as described above, the elastic contact force to each inspection point of the substrate to be inspected is different, and each inspection point is Since the contact pressure of the contact head 8a of the wire probe 8 is different, there is a problem that the reliability of the inspection accuracy may be insufficient particularly in the inspection of electronic components such as ICs that operate with a small current.

Furthermore, since the contact head 8a is elastically contacted with each inspection point on the board to be inspected by elastic deformation due to the buckling of the wire probe 8, the number of inspections of the electrical characteristics of the circuit board is performed. Therefore, the metal fatigue of the wire probe 8 increases, and there is a problem in terms of durability.

The present invention has been made in consideration of such circumstances, and the probes can be arranged at a fine pitch, the contact pressure to the inspection points can be made uniform, and the inspection accuracy can be improved. It is an object of the present invention to provide a probe for testing an electric circuit, which is capable of improving the electric resistance and improving the durability.

[0016]

The invention according to claim 1 is
A probe for an electric circuit test for performing an electric circuit test by elastically contacting a single linear probe held by a guide holder and a pin holding block to an inspection point of a circuit board to be inspected, which is an intermediate part of the probe. Has a curved part formed by bending,
The probe is elastically contacted with the inspection point by the deformation of the curved portion.

The invention according to claim 2 is characterized in that the single linear probe is formed of a shape memory alloy.

The invention according to claim 3 is characterized in that the single linear probe is formed of a superelastic alloy.

According to a fourth aspect of the present invention, a plurality of the single linear probes are implanted in the guide holder and the pin holding block, and the direction of the curved portion of the probe is unified, and the probe is provided. One end side of each of which is elastically contacted with the inspection point is slidably held on the guide holder side, and each other end side of the probe is held on the pin holding block side. To do.

[0020]

In the electric circuit test probe of the present invention, the elastic contact force to the inspection point of the probe can be obtained by the bending portion provided at the intermediate portion of the probe by the bending process.

Further, when a plurality of single linear probes are implanted in the guide holder and the pin holding block, the directions of the curved portions of the probes are unified, so that no contact occurs due to elastic deformation between the probes. Therefore, the pitch interval of each probe can be narrowed.

Further, since the guide holder and the pin holding block are detachably attached to the pin holding plate, the probe can be easily replaced by replacing the guide holder and the pin holding block.

Furthermore, since the restored state of the curved portion of each probe can be unified by forming the single linear probe by the shape memory alloy, the elastic contact force of the probe to the inspection point of the circuit board to be inspected. Can be made uniform, and the elastic contact force is also made uniform, so that the inspection accuracy can be improved.

Further, since the protrusion of the probe restores the bending portion to a memorized state by applying heat to the bending portion, metal fatigue due to elastic deformation unlike the conventional case does not occur, so that it is durable. Sexual problems can also be resolved.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 4 shows an embodiment of the electric circuit test probe of the present invention. As shown in the figure, the probe card 20, which is the base substrate, is provided with a plurality of lead patterns 21 connected to a circuit test universal tester (not shown). A pin holding plate 22 made of an insulating material is attached to the center of the probe card 20. When the pin holding plate 22 is attached, a screw (not shown) is attached to a screw hole 23 provided around the pin holding plate 22, so that the pin holding plate 22 is fixed to the central portion of the probe card 20.

At the center of the pin holding plate 22, a pin holding block 24 which is a test head and a guide holder 2 are provided.
5 is attached. When attaching the pin holding block 24 and the guide holder 25, by attaching a screw (not shown) to a screw hole (not shown) provided around the pin holding block 24 and the guide holder 25, the pin holding block 24 The guide holder 25 is fixed to the central portion of the pin holding plate 22. A hot air blowing port 26 through which hot air is blown is provided at the outer peripheral edge of the guide holder 25, and hot air is blown through the hot air blowing port 26 during inspection.

A head portion 31 of the probe 30 is projected above the guide holder 25 at the same height. The probe 30 is provided with a bending portion 32 that is bent. Here, the probe 30 is formed of a shape memory alloy composed of Ti—Ni, Cu-based Cu—Al—Ni, or Cu—Zn—Al alloy,
The curved portion 32 is restored to the stored state by the hot air blown through the hot air blowing port 26. The probe 30 is not limited to the shape memory alloy and may be formed of a super elastic alloy.

A contact regulating pin 30A is provided on the outer peripheral edge of the guide holder 25 so as to project therefrom. Here, the height of the contact regulation pin 30A is higher than that of the head 31 of the probe 30. When hot air is blown through the hot air blowing port 26 and the bending portion 32 is restored to the memory state, the height of the head portion 31 thereof exceeds the contact regulating pin 30A.

FIG. 5 shows the mounting state of the probe 30. The head 31 of the probe 30 is attached to the guide holder 2.
5 is inserted into the insertion hole 26a of the guide plate 26. The other part of the probe 30 includes a holding plate 27,
Insertion holes 27a, 28a, 29 of 28 and 29A, respectively.
It is inserted in a. The other end side of the probe 30 is electrically connected to the cable 40 via a connecting member 41 described later. The cable 40 is inserted through the insertion holes 29a of the holding plates 29B and 29C.

A curved portion 32 provided on the probe 30.
Is held between the holding plates 27 and 28, and the curved portion 32 contacts the holding plates 27 and 28 to prevent the probe 30 from coming off. In addition, the protruding direction of the curved portion 32 of each probe 30 is aligned with the direction orthogonal to the arrangement direction of the probe 30. As a result, since the deformation direction of the bending portion 32 is set to the protruding direction of the bending portion 32, the probes 30 do not come into contact with each other, so that the pitch between the adjacent probes 30 can be narrowed.

The air gap 25A provided in the guide holder 25 communicates with the hot air blowing port 26 so that the hot air blown from the hot air blowing port 26 is blown to the curved portion 32 of each probe 30. It has become.
Thereby, as shown in FIG. 4, the curved portion 32 of each probe 30 is restored from the state shown by the broken line to the state shown by the solid line, so that the height of the head 31 of each probe 30 causes the contact regulating pin 30A to move. The elastic force of the bending portion 32 elastically contacts the inspection point on the inspection surface side of the circuit board to be inspected (not shown).

The connecting member 41 for electrically connecting the probe 30 and the cable 40 has the structure shown in FIG. That is, in the conductive cylindrical body 42 of the connection member 41,
The cable 40 is fixed by soldering. Cylinder 42
A movable pin 44 biased upward by a coil spring 43 is provided inside. The conductive contact portion 45 provided on the head of the movable pin 44 elastically contacts the acute-angled other end portion side of the probe 30 by the biasing force of the coil spring 43.

In the electric circuit test probe having such a configuration, when the circuit board to be inspected (not shown) is pressed against the probe 30 side during inspection, the inspection surface side of the circuit board to be inspected contacts the contact regulating pin 30A. Contact. In this state, the head 31 of the probe 30 is located lower than the contact regulating pin 30A, so that the head 31 of the probe 30 does not come into contact with the inspection point on the inspection surface side of the circuit board to be inspected.

When hot air is blown into the space 25A through the hot air blowing port 26 provided in the guide holder 25 from this state, the temperature inside the space 25A rapidly rises.
As a result, in the normal state, the curved portion 32 at the position shown by the broken line in FIG. 6 is restored to the state shown by the solid line which is the stored state by the heat of the hot air, so that the head 31 of each probe 30 comes into contact with the contact regulating pin. Protruding until it exceeds the height of 30A,
Due to the elastic force of the bending portion 32, the head portion 31 elastically contacts the inspection point on the inspection surface of the circuit board to be inspected. At this time, the protrusion amount of the head portion 31 of each probe 30 due to heat is made equal because the stored state of the curved portion 32 to be restored is unified, so that the inspection surface of the circuit board to be inspected is inspected. The elastic contact of the head 31 with the points is performed uniformly.

Thus, the inspection points on the inspection surface of the circuit board to be inspected are conducted through the head portion 31 of the probe 30, the connecting member 41 and the cable 40, and various inspections are performed by a circuit test universal tester (not shown). Done.

The pin holding block 24, which is the test head, and the guide holder 25 are replaced by the pin holding plate 2
This can be easily performed by removing a screw (not shown) attached to the No. 2. Furthermore, the replacement of the individual probes 30 is performed by blowing hot air onto the bending portion 32,
Can be easily performed by pulling out, for example, the other end portion side of the probe 30 while keeping the straight state, and inserting a new probe 30 in the straight state in the reverse direction. In addition, when the probe 30 is made of a super elastic alloy, the curved portion is easily deformed, so after pulling out the other end as it is,
This can be easily performed by inserting a new probe 30 in reverse.

As described above, in this embodiment, the protruding direction of the curved portion 32 of each probe 30 is aligned with the direction orthogonal to the arrangement direction of the probe 30, and each probe 30 is arranged.
Since the bending directions of the curved portions 32 are the same, the probes 30 do not come into contact with each other. Therefore, the pitch between the adjacent probes 30 can be narrowed, and the lead wires having a narrow pitch can be provided. It is possible to easily inspect electronic components such as the IC components.

The amount of protrusion of the head 31 of each probe 30 due to heat is the same as the head of the circuit board to be inspected on the inspection surface because the stored state of the curved portion 32 to be restored is unified. Since the elastic contact of the portion 31 is uniformly performed, the elastic contact force of the inspection surface of the circuit board to be inspected to the inspection point becomes uniform,
Damage to inspection points is avoided.

Further, since the head portion 31 of the probe 30 is elastically contacted with each inspection point evenly, the contact resistance and the like can be kept uniform even when inspecting an electronic component such as an IC which operates with a minute current. The reliability of inspection accuracy can be improved.

Furthermore, since the projection of the head 31 of the probe 30 restores the bending portion 32 to the memory state by applying heat to the bending portion 32, it is elastically deformed as in the conventional case. Since metal fatigue does not occur, problems in terms of durability can be solved.

In the present embodiment, the case where the curved portion 32 has a semi-arcuate shape has been described, but the present invention is not limited to this example. For example, as shown in FIG. 8, a curved portion 32A having a rectangular shape may be used. .

[0042]

As described above, according to the electric circuit test probe of the present invention, it is possible to obtain the elastic contact force of the probe to the inspection point by the bending portion provided at the intermediate portion of the probe by the bending process.

Further, when a plurality of single linear probes are implanted in the guide holder and the pin holding block, the directions of the curved portions of the probes are unified, so that no contact occurs due to elastic deformation between the probes. Therefore, the pitch interval of each probe can be narrowed.

Further, since the guide holder and the pin holding block are detachably attached to the pin holding plate, the probe can be easily replaced by replacing the guide holder and the pin holding block.

Furthermore, since the restored state of the curved portion of each probe can be unified by forming the single linear probe by the shape memory alloy, the elastic contact force of the probe to the inspection point of the circuit board to be inspected. Can be made uniform, and the elastic contact force is also made uniform, so that the inspection accuracy can be improved.

Further, since the protrusion of the probe restores the bending portion to a memorized state by applying heat to the bending portion, metal fatigue due to elastic deformation as in the conventional case does not occur, so that it is durable. Sexual problems can also be resolved.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a conventional probe card for circuit inspection finely formed on a silicon wafer.

2 is a diagram showing the probe card of FIG. 1. FIG.

FIG. 3 is a cross-sectional view showing an example of a conventional electric circuit test probe.

FIG. 4 is a perspective view showing an embodiment of an electric circuit test probe of the present invention.

5 is a cross-sectional view showing the internal configuration of the electric circuit test probe of FIG.

6 is a cross-sectional view showing an internal configuration of the electric circuit test probe of FIG.

7 is a cross-sectional view showing a connecting member for connecting the probe of FIG. 5 and a cable.

FIG. 8 is a diagram showing another embodiment in which the shape of the curved portion of FIG. 6 is changed.

[Explanation of symbols]

 20 probe card 22 pin holding plate 24 pin holding block 25 guide holder 26 hot air blowing port 30 probe 30A contact regulation pin 31 head 32 curved portion 40 cable 41 connection member

Claims (4)

[Claims] 1. An electric circuit test probe for performing an electric circuit test by elastically contacting a single linear probe held by a guide holder and a pin holding block to an inspection point of a circuit board to be inspected, A probe for electric circuit testing, wherein a curved portion formed by a bending process is provided at an intermediate portion of the probe, and the probe is elastically contacted with an inspection point by deformation of the curved portion. 2. The electric circuit test probe according to claim 1, wherein the single linear probe is made of a shape memory alloy. 3. The electric circuit test probe according to claim 1, wherein the single linear probe is made of a superelastic alloy. 4. A plurality of the single linear probes are implanted in the guide holder and the pin holding block, and the direction of the curved portion of the probe is unified, and the probe is elastic at the inspection point. 3. One of the contacted one ends is slidably held on the guide holder side, and the other end of each probe is held on the pin holding block side. Alternatively, the electric circuit test probe described in 3 above.