JP2004340597A - Contact probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide structure capable of returning a plunger surely to a normal position, and capable of realizing normal contact all the time. <P>SOLUTION: A conical recessed part area 116 is provided in a rear end shaft part 114 of the plunger 102 to receive an end part of a torsion coil spring 103 as fit-in preventive structure. An end part area 103a of the torsion coil spring 103 is provided to make an outside diameter dimension smaller than that of other area 103b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a contact probe, and more particularly, to a structure of a contact probe used in an inspection apparatus for performing an electrical inspection on a circuit to be inspected such as a semiconductor substrate.
[0002]
[Prior art]
A contact probe is used when the semiconductor device is pressed against a lead of a semiconductor device or an electrode portion of a component mounted on a printed circuit board to inspect an open, short, or other operation function of the component.
[0003]
Here, a structure of a contact probe used for inspecting an operation function of a semiconductor device will be described.
[0004]
2. Description of the Related Art A semiconductor device is shipped from a semiconductor device maker after a terminal called a lead is soldered and mounted on a printed circuit board and then subjected to an inspection process. In an operation function test of a semiconductor device, a contact probe is pressed against a lead, and a test signal is exchanged between the semiconductor device and a tester (generally called a tester). At this time, the contact probe is normally contacted and used with an appropriate contact resistance value or less.
[0005]
In general, there is variation in the height dimension of the lead of a semiconductor device. Therefore, in order to absorb the dimensional error, a sliding mechanism of a plunger using a biasing force of a spring for a contact probe is employed. .
[0006]
In addition, since an oxide film is formed on the surface of the lead of the semiconductor device, a contact pressure is applied to the contact probe for breaking through the oxide film and directly contacting the lead. Therefore, it is indispensable to adopt a plunger sliding mechanism using the urging force of the spring.
[0007]
Here, the structures of two types of contact probes in the related art will be described below with reference to FIGS. First, a conventional contact probe 100C will be described with reference to FIG. In addition, in order to easily understand the internal structure in the drawing, a part is shown in a broken state.
[0008]
(Contact probe 100C)
The contact probe 100C includes a barrel 101 having a cylindrical shape, a torsion coil spring 103 disposed in the barrel 101, a tip end portion exposed from the inside of the barrel 101, and a rear end portion formed by the torsion coil spring 103. And a plunger 102 urged toward the distal end side and slidably accommodated in the barrel 101.
[0009]
The plunger 102 is provided so as to be in contact with the conical tip shaft portion 111, the sliding shaft portion 112, the connecting shaft portion 113 having an outer diameter smaller than the sliding shaft portion 112, and the inner peripheral wall of the barrel 101. An end shaft portion 114 and a conical spring contact shaft portion 115 extending rearward from the rear end shaft portion 114 are formed.
[0010]
The electric signal in the contact probe 100C is mainly transmitted from the plunger 102 to the inner peripheral wall of the barrel 101 by selecting a path having a small electric resistance and a small inductance.
[0011]
Since the torsion coil spring 103 has a large electric resistance and a large inductance, it cannot be a main path of an electric signal in the contact probe 100C.
[0012]
In the contact probe 100C, the material and surface plating of each part, and the gap (clearance) between the plunger 102 and the inner peripheral wall of the barrel 101 are highly reliable so that the electric signal flows smoothly from the plunger 102 to the barrel 101. This is an important factor for obtaining the contact probe 100C. For example, in the contact probe 100C in which the plunger 102 is pushed in about 1.2 mm, a contact resistance of about several tens mΩ and durability of several hundred thousand times are required.
[0013]
(Contact probe 200C)
Next, a conventional contact probe 200C will be described with reference to FIG. In addition, in order to easily understand the internal structure in the drawing, a part is shown in a broken state.
[0014]
The basic configuration of the contact probe 200C is the same as that of the contact probe 100C, and includes a barrel 201 having a cylindrical shape, a torsion coil spring 205 disposed in the barrel 201, and a distal end portion in the barrel 201. And a shaft-shaped plunger 202, which is exposed from the rear end and urged toward the front end by a torsion coil spring 205, and is slidably received in the barrel 201. As a characteristic configuration of the contact probe 200C, a spherical plunger 204 made of a ball member (generally made of metal) is disposed between the rear end of the axial plunger 202 and the torsion coil spring 205. ing.
[0015]
The shaft-shaped plunger 202 has a conical tip shaft 211, a sliding shaft 212, a connecting shaft 213 having a smaller outer diameter than the sliding shaft 212, and a rear shaft 214. Further, a bias 214a having an end surface obliquely cut in one direction is provided on a contact surface of the rear end shaft portion 214 with the spherical plunger 204.
[0016]
The path of the electric signal of the contact probe 200C having the above configuration is the same as that of the contact probe 100C. However, when the axial plunger 202 is pushed into the barrel 201, the electric signal passes through the torsion coil spring 205 via the spherical plunger 204. Power. At this time, since the bias 214a is provided in a region of the shaft-shaped plunger 202 that comes into contact with the spherical plunger 204, the shaft-shaped plunger 202 slides in a certain direction while being strongly pressed against the inner peripheral wall of the barrel 201. become. As a result, an electric signal path is reliably secured between the axial plunger 202 and the barrel 201. Therefore, from the viewpoint of securing an electric signal path, it can be said that the structure of the contact probe 200C shown in FIG. 6 has higher reliability than the structure of the contact probe 100C shown in FIG. The following patent documents disclose the structure of the contact probe.
[0017]
[Patent Document 1]
JP-A-56-094272
[Patent Document 2]
Japanese Utility Model Laid-Open No. 63-111671
[Problems to be solved by the invention]
In the operation function test of the semiconductor device using the contact probe having the above-described configuration, a contact failure occurs, that is, a failure occurs in which the contact pressure does not fall below an appropriate contact resistance value due to normal contact. One cause of the contact failure is a phenomenon in which the plunger remains pushed into the barrel, and a normal contact pressure cannot be obtained at the next inspection.
[0020]
The cause of this phenomenon is that, in the case of the contact probe 100C shown in FIG. 5, as shown in FIG. 7, the end of the torsion coil spring 103 abuts against the axle shaft portion 115 to be pushed outward, resulting in the plunger. The plunger 102 and the torsion coil spring 103 are both fixed to the barrel 101 when the end of the torsion coil spring 103 is fitted between the contact shaft portion 115 of the cylinder 102 and the inner peripheral wall surface of the barrel 101. caused by. In the case of the contact probe 200C shown in FIG. 6, the same phenomenon can occur because the end of the torsion coil spring 205 fits between the spherical plunger 204 and the inner peripheral wall surface of the barrel 201.
[0021]
Therefore, the present invention has been made in order to solve the above-described problem, and provides a contact probe having a structure capable of reliably returning a plunger to an original normal position and always realizing a normal contact. The purpose is to do.
[0022]
[Means for Solving the Problems]
According to the contact probe based on the present invention, in the contact area between the rear end side of the plunger and the torsion coil spring, the end of the torsion coil spring between the outer peripheral surface of the plunger and the inner peripheral wall surface of the barrel is provided. A fitting prevention structure for preventing the fitting is provided. By adopting this structure, the end of the torsion coil spring is prevented from being fitted between the outer peripheral surface of the plunger and the inner peripheral wall surface of the barrel, and the plunger can always slide within the barrel, and the normal operation can be achieved. Contact can always be realized.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the structure of a contact probe in each embodiment based on the present invention will be described with reference to the drawings. Note that the same or corresponding parts as those of the structure of the contact probe in the related art are denoted by the same reference numerals, and overlapping description is avoided, and the characteristic structure of the contact probe in each embodiment is described in detail. I do. In addition, in each figure, in order to easily understand the internal structure, it is shown in a partially broken state.
[0024]
(Embodiment 1)
The structure of contact probe 100A according to the first embodiment will be described with reference to FIG.
[0025]
<Contact probe 100A>
The characteristic structure of the contact probe 100A is different from the structure of the conventional contact probe 100C shown in FIG. 5 in that the end of the torsion coil spring 103 is inserted into the rear end shaft 114 of the plunger 102 as a fitting prevention structure. The point is that a conical concave region 116 is provided for receiving. Note that the conical shape is an example, and a spherical shape, a cylindrical shape, or another concave shape can be adopted.
[0026]
Further, as a further preferred embodiment, the end region 103a of the torsion coil spring 103 is provided to have an outer diameter smaller than that of the other region 103b. For example, when the wire diameter of the torsion coil spring 103 is several tens of μm, the outer diameter of the end region 103a is about 200 μm or less, and the outer diameter of the other area 103b is about 300 μm or less. Further, as the end region 103a, it is sufficient that the end region 103a is wound several turns from the end of the torsion coil spring 103.
[0027]
In the case of the contact probe 100A having this configuration, since the end of the torsion coil spring 103 fits into the recessed region 116, the expansion of the end of the torsion coil spring 103 due to being pushed by the plunger 102 of the contact probe 100A is suppressed. You. As a result, the torsion coil spring 103 is inserted into the gap between the outer peripheral surface of the rear end shaft portion 114 of the plunger 102 and the inner peripheral wall surface of the barrel 101 when the plunger 102 slides left and right or up and down during contact. The end portion 103a can be prevented from being fitted, and the plunger 102 can be reliably returned to the original normal position.
[0028]
(Embodiment 2)
Next, the structure of contact probe 200A according to the second embodiment will be described with reference to FIG.
[0029]
<Contact probe 200A>
The characteristic structure of the contact probe 200A is different from the structure of the conventional contact probe 200C shown in FIG. 6 in that the end region 205a of the torsion coil spring 205 is smaller than the other region 205b as a fitting prevention structure. The point is that it is provided so as to have an outer diameter. For example, when the outer diameter of the spherical plunger 204 is approximately φ500 μm and the wire diameter of the torsion coil spring 205 is several tens μm, the outer diameter of the end region 205a is approximately φ200 μm or less, and the outer diameter of the other region 205b. The dimensions are about φ300 μm or less. In addition, as the end region 205a, it is sufficient to have several turns from the end of the torsion coil spring 205.
[0030]
In the case of the contact probe 200A having this configuration, even when pressed by the spherical plunger 204, the end region 205a of the torsion coil spring 205 is provided so as to have an outer diameter smaller than that of the other region 205b. Therefore, the expansion of the end of the torsion coil spring 205 is suppressed. As a result, the end portion 205a of the torsion coil spring 205 between the outer peripheral surface of the spherical plunger 204 and the inner peripheral wall surface of the barrel 201, which is generated when the spherical plunger 204 slides left and right or up and down at the time of contact. It is possible to prevent the plunger from getting stuck, and it is possible to reliably return the plunger 203 to the original normal position.
[0031]
(Embodiment 3)
Next, the structure of contact probe 100B according to the third embodiment will be described with reference to FIG.
[0032]
<Contact probe 100B>
The characteristic structure of the contact probe 100B is that the outer peripheral surface of the rear end shaft portion (second shaft portion) 114 of the plunger 102 is different from the structure of the contact probe 100A shown in FIG. (A first shaft portion 113).
[0033]
In this manner, by making the outer peripheral surface of the rear end shaft portion 114 in contact with the inner peripheral wall surface of the barrel 101 substantially spherical, a smooth surface contact is realized in the contact between the inner peripheral wall surface of the barrel 101 and the rear end shaft portion 114. It becomes possible to do. In the conventional structure, grinding of the inner peripheral wall surface of the barrel 101 (peeling of gold plating applied to the inner peripheral wall surface) by an edge generated on a cut surface of the rear end shaft portion 114 has become a problem. By adopting the structure of the embodiment, the generation of wear powder and cutting powder at the contact between the inner peripheral wall surface of the barrel 101 and the rear end shaft 114 is prevented, and the plunger 102 returns due to the generation of wear powder and cutting powder. It is possible to avoid the occurrence of defects.
[0034]
(Embodiment 4)
Next, the structure of contact probe 200B according to the fourth embodiment will be described with reference to FIG.
[0035]
<Contact probe 200B>
The characteristic structure of the contact probe 200B differs from the structure of the contact probe 200A shown in FIG. And a second shaft portion 214c including a bias 214a, and an outer peripheral surface of the second shaft portion 214c has a substantially spherical shape projecting outward from the first shaft portion 214b. On the point.
[0036]
As described above, by making the outer peripheral surface of the second shaft portion 214c that is in contact with the inner peripheral wall surface of the barrel 201 into a substantially spherical shape, a smooth surface contact is realized in the contact between the inner peripheral wall surface of the barrel 201 and the second shaft portion 214c. It becomes possible to do. In the conventional structure, grinding of the inner peripheral wall surface of the barrel 201 (peeling of the gold plating applied to the inner peripheral wall surface) by the edge generated on the cut surface of the rear end shaft portion 214 has become a problem. By adopting the structure in the form described above, the generation of wear powder and cutting powder in the contact between the inner peripheral wall surface of the barrel 201 and the second shaft portion 214c is prevented, and the plunger 203 caused by the generation of wear powder and cutting powder is prevented. It is possible to avoid the occurrence of a return failure.
[0037]
It should be noted that each of the above-described embodiments is merely an example in all respects and is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0038]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the contact probe based on this invention, it becomes possible to provide the contact probe provided with the structure which can always return a plunger to the original normal position and can always implement a normal contact.
[Brief description of the drawings]
FIG. 1 is an overall view showing a structure of a contact probe according to a first embodiment based on the present invention.
FIG. 2 is an overall view showing a structure of a contact probe according to a second embodiment based on the present invention.
FIG. 3 is a partial view showing a structure of a contact probe according to a third embodiment based on the present invention.
FIG. 4 is a partial view showing a structure of a contact probe according to a fourth embodiment based on the present invention.
FIG. 5 is an overall view showing a structure of a contact probe according to a conventional technique (first).
FIG. 6 is an overall view showing a structure of a contact probe according to a conventional technique (second).
FIG. 7 is an enlarged view showing a problem of a contact probe in the related art.
[Explanation of symbols]
100A, 100B, 200A, 200B Contact probe, 101, 201 barrel, 102 plunger, 103, 205 Torsion coil spring, 103a, 205a End region, 103b, 205b Other region, 111, 211 Tip shaft portion, 112, 212 Sliding Dynamic shaft part, 113 connecting shaft part (first shaft part including the front end part), 114 rear end shaft part (second shaft part), 115 contact shaft part, 116 concave area, 203 axial plunger, 204 spherical plunger 213, connecting shaft part, 214 rear end shaft part, 214a bias, 214b first shaft part, 214c second shaft part.

Claims (6)

A barrel having a cylindrical shape, a torsion coil spring disposed in the barrel, a tip end side is exposed from the inside of the barrel, and a rear end side is urged toward the tip end by the torsion coil spring, A plunger slidably received within the barrel, comprising:
In the contact area between the rear end of the plunger and the torsion coil spring, to prevent the end of the torsion coil spring from being fitted between the outer peripheral surface of the plunger and the inner peripheral wall surface of the barrel. A contact probe, wherein a contact preventing structure is provided. 2. The contact probe according to claim 1, wherein a recessed region for receiving an end of the torsion coil spring is provided at a rear end of the plunger abutting on an end of the torsion coil spring as the fitting prevention structure. 3. . The contact probe according to claim 2, wherein an end region of the torsion coil spring has a smaller outer diameter than other regions. The plunger is
A first shaft portion including a tip portion side, and a second shaft portion provided with the concave region,
4. The contact probe according to claim 2, wherein an outer peripheral surface of the second shaft portion has a substantially spherical shape projecting outward from the first shaft portion. 5. The plunger is
An axial plunger, and a spherical plunger disposed between the axial plunger and the torsion coil spring;
2. The contact probe according to claim 1, wherein the end region of the torsion coil spring has an outer diameter smaller than other regions as the fitting prevention structure. 3. The axial plunger,
A first shaft portion including a tip portion side, and a second shaft portion provided on a side that comes into contact with the spherical plunger,
The contact probe according to claim 5, wherein an outer peripheral surface of the second shaft portion has a substantially spherical shape extending outward from the first shaft portion.

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