JP2010139344A - Contact pin and contact probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact pin and a contact probe capable of mitigating stress concentration on a specific portion by devising the shape of a spring, and enlarging displacement by enhancing flexibility. <P>SOLUTION: In the contact pin 30, a plunger 40 and the spring 60 are formed in a body from a conductive material, and the spring 60 is formed by connecting a plurality of rings by using a pair of facing vertexes of each hexagonal ring 61 as connection points, and a pair of two sides constituting the vertex which is the connection point are bent to the inward direction of the ring, respectively. The contact probe 20 has a structure wherein the contact pin 30 is inserted into a conductive tube 70. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a contact pin used for electrical inspection of an electronic component to be inspected such as an IC chip and a contact probe including the contact pin.

  In general, inspection of a circuit of an electronic component to be inspected such as an IC chip is performed by using an inspection apparatus having a large number of contact probes. Further, due to further increase in density and miniaturization of circuits to be inspected in recent years, it is necessary to mount more contact probes on the inspection apparatus side at high density (for example, at a pitch of 0.1 mm or less). It has become to.

  An example of a conventional contact probe 1 is shown in FIG. The contact probe shown in FIG. 5 includes a tube 2 that is a metal cylindrical body, plungers 3 and 4 that can protrude from both ends thereof, and a spring 5 that biases both plungers 3 and 4 in the protruding direction. . In use, the contact probe 1 is disposed in an insulating housing 6 on the inspection apparatus side.

  In this contact probe 1, it is necessary to machine the components individually and then assemble them, and the components are also miniaturized to be mounted at a high density, which makes both machining and assembly difficult. .

As a method for solving this problem, a contact probe in which a plunger portion and a spring portion are integrated as in Patent Document 1 below has been proposed.
JP 2001-343397 A

  The shape of the spring portion shown in Patent Document 1 is a configuration in which circular or elliptical rings are integrally connected. However, these shapes are prone to stress concentration when a load is applied, and are highly rigid. Can not get displacement efficiently. The reason will be described in detail below with reference to FIG.

(1) In the structure of the spring part of FIG. 6, since the connection part of the circular ring 10 is thick, it is difficult to deform compared with other parts, and stress is concentrated in the vicinity (part a in FIG. 6). .

(2) Part b of FIG. 6 is a part where stress is concentrated due to the shape of the circular ring.

(3) The arch portion (c portion in FIG. 6) that supports the load vertically is highly rigid and difficult to deform.

  As described above, in the configuration of the spring portion in which the circular rings are continuous, stress concentrates at the two locations (a portion and b portion) of each circular ring and the shape is highly rigid. I can't take it big. The same is true when an elliptical ring shape is used.

  As described above, in the spring portion in which circular or elliptical rings are integrally connected, there is a problem that stress concentration is likely to occur at a specific portion when a load is applied, and the rigidity is high and the amount of displacement is small.

  The present invention has been made in view of such a situation, and its purpose is to devise the shape of the spring part to relieve stress concentration on a specific part and to bend easily to increase the amount of displacement. It is to provide a contact pin and a contact probe.

  Other objects and novel features of the present invention will be clarified in embodiments described later.

In order to achieve the above object, in a contact pin according to an aspect of the present invention, the plunger portion and the spring portion are integrally formed of a conductive material,
The spring portion is formed by connecting a plurality of rings with a pair of opposing vertices of a hexagonal ring as a connecting portion,
A pair of two sides constituting the apex as the connecting portion are each curved inward of the ring.

  The said aspect WHEREIN: It is good for a pair of edge | side which connects the vertex which does not comprise the said connection part to each curve to the outward direction of the said ring.

  The said aspect WHEREIN: It is good to form so that wall thickness may become thin as a pair of 2 sides which comprise the vertex which is the said connection part leaves | separates from the said connection part. Moreover, it is good to form so that the wall thickness of a pair of edge | side which connects the vertex which does not comprise the said connection part becomes larger than the minimum value of the wall thickness of a pair of 2 sides which comprise the vertex which is the said connection part.

  Another aspect of the present invention is a contact probe, wherein the contact pin is inserted into a conductive tube, and a distal end portion of the plunger portion protrudes from the tube end.

  It should be noted that any combination of the above-described constituent elements, and those obtained by converting the expression of the present invention between methods and systems are also effective as aspects of the present invention.

  According to the present invention, by devising the shape of the spring portion, the stress concentration on the specific part can be eased, and the amount of displacement can be increased by making it easy to bend, so that even a larger displacement does not break. Is possible.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, process, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  1 and 2, the contact probe 20 includes a contact pin 30 in which plunger portions 40, 50 and a spring portion 60 are integrally formed of a conductive material, and a conductive cylindrical tube 70. The tip portions 41 and 51 of the plunger portions 40 and 50 protrude from the tube end. The contact pin 30 is preferably a hard metal such as a palladium-based alloy or a nickel-based alloy, and the plunger portions 40, 50 and the spring portion 60 are integrally formed by etching a metal plate or the like. The tube 70 is preferably a metal having good conductivity such as copper.

  As shown in FIGS. 3 and 4, the spring portion 60 formed integrally with the contact pin 30 is formed by integrally connecting a plurality of rings 61 with a pair of opposing vertices of the hexagonal ring 61 as connecting portions 62. The pair of two sides 63 constituting the apex as the connecting portion 62 are curved inward of the ring 61, respectively. In addition, a pair of sides 64 that connect vertices that do not constitute the connecting portion 62 are curved outward of the ring 61. Each ring 61 is bilaterally symmetric with respect to a straight line connecting the connecting portions 62, and is also vertically symmetric with respect to an orthogonal line orthogonal to the straight line at the midpoint of the connecting portions 62.

  As shown in FIGS. 3 and 4B, it is desirable that the pair of two sides 63 constituting the apex as the connecting portion 62 be formed so that the wall thickness becomes thinner as the distance from the connecting portion 62 increases. At this time, the wall thickness of the pair of sides 64 connecting the vertices that do not constitute the connecting portion 62 is sufficiently larger than the minimum wall thickness of the side 63 (similar to the wall thickness of the side 63 near the connecting portion 62). Is formed.

  The reason for the ring shape is as follows.

(1) When the pair of two sides 63 constituting the apex as the connecting portion 62 is curved inward of the ring 61, the two sides 63 serving as a beam are easily bent and a load (stress) is applied. Earn the amount of displacement.

(2) Since the pair of two sides 63 constituting the apex as the connecting portion 62 are formed so that the wall thickness decreases as the distance from the connecting portion 62 increases, the stress applied to the vicinity of the connecting portion of the two sides 63 serving as a beam Are distributed over the entire side so that they are not damaged even by larger displacements.

(3) Since the pair of sides 64 connecting the vertices that do not constitute the connecting portion 62 are side portions and portions where stress is concentrated, the wall thickness is sufficiently larger than the minimum value of the wall thickness of the side 63. By making it large, damage due to stress concentration is prevented.

  4A is a stress distribution in the case of a ring having a constant wall thickness at the sides 63 and 64, and FIG. 4B is a wall thickness adjustment (the wall thickness is reduced as the side 63 is moved away from the connecting portion 62, and the side 64 is adjusted. The analysis result of the stress distribution of the ring after (the wall thickness of is sufficiently thick) is shown (however, the dotted line in the figure shows the ring shape before the stress is applied). The higher the stress, the darker the paint, and the lower stress the light.

  In FIG. 4 (A), the wall shape is adjusted in such a way that the wall is thinned in a place where stress is not so much applied, and the wall is adjusted so that the wall is thickened in a place where stress is concentrated. is there. As shown in FIG. 4B, by adjusting the wall cross-sectional area of the ring 61, the stress is dispersed (the coating is thin as a whole), and a shape that does not break even with a larger displacement can be obtained.

  As shown in FIGS. 1 and 2, the contact probe 20 is formed by inserting a contact pin 30 in which the spring portion 60 and the plunger portions 40 and 50, in which the ring 61 is continuous, into the conductive cylindrical tube 70. The upper end portion of the tube 70 is caulked, and a sharp tip portion (narrow width portion) 41 of the upper plunger portion 40 projects from the upper end opening of the tube 70. The base portion 42 of the upper plunger portion 40 is wide so that the upper end opening of the tube 70 is caught. The tube 70 is a highly conductive metal such as copper having better conductivity than the contact pin 30, and the spring portion 60 has a function of maintaining the integral contact pin 30 straight, and the plunger portions 40, 50. The contact probe 20 has a function of reducing the electrical resistance of the entire contact probe 20 by being in electrical contact with the contact probe 20.

  The lower plunger portion 50 has a pointed tip portion (narrow width portion) 51, an intermediate portion 52, and a base portion 53, and the intermediate portion 52 is a stopper wider than the tip portion 51 and the base portion 53. .

  1 and 2 show a case where the lower plunger portion 50 of the contact probe 20 is brought into contact with a solder ball 96 (which may be an electrode pad) on an inspection target 95 such as a semiconductor wafer or a printed circuit board. 1 shows a state before contact, and FIG. 2 shows a state at the time of contact. As shown in these drawings, the contact probe 20 is inserted into the mounting hole 81 of the insulative housing 80 on the inspection apparatus side when in use. At this time, the lower portion of the mounting hole 81 is a small-diameter portion 82, and only the sharp tip portion 51 of the lower plunger portion 50 penetrates the small-diameter portion 82 and protrudes from the lower surface of the insulating housing 80. The intermediate portion 52 is wider than the diameter of the small diameter portion 82 and functions as a stopper that abuts against the bottom of the large diameter portion 83 of the mounting hole 81 in which the tube 70 is disposed to restrict the protruding amount of the tip portion 51. To do.

  A printed circuit board 90 on the inspection apparatus side is placed and fixed on the upper side of the insulating housing 80, and the pointed tip 41 of the upper plunger section 40 is in elastic contact with the electrode terminal 91 on the lower surface of the printed circuit board 90. Yes.

  In the state before the lower plunger portion 50 in FIG. 1 contacts the solder ball 96, the wide intermediate portion 52 of the plunger portion 50 abuts against the bottom portion of the large diameter portion 83, and the lower surface of the insulating housing 80 at the tip portion 51. The amount of protrusion from the maximum value.

  In order to inspect the inspection object 95 such as a semiconductor wafer or a printed circuit board, the insulating housing 80 is lowered as shown in FIG. 2, and the tip 51 of the lower plunger 50 is brought into contact with the solder ball 96 of the inspection object 95. When this occurs, the tip portion 51 comes into elastic contact with the solder ball 96 as the spring portion 60 bends and contracts.

  According to the present embodiment, the following effects can be achieved.

(1) The contact probe 20 is obtained by inserting a contact pin 30 in which plunger portions 40, 50 and a spring portion 60 are integrally formed of a conductive material into a conductive tube 70, and has a simple structure with a small number of parts. In addition, miniaturization and diameter reduction are possible. As a result, the contact probes 20 can be mounted in the insulating housing 80 on the inspection apparatus side with high density (for example, with a pitch of 0.1 mm or less).

(2) By devising the shape of the spring part 60, it is possible to alleviate the stress concentration on a specific part, to bend easily and to increase the amount of displacement, and to prevent destruction even with larger displacements. is there. That is, (a) the pair of two sides 63 constituting the apex as the connecting portion 62 is curved inwardly of the ring 61, so that the two sides 63 serving as a beam are easily bent and a load (stress) is applied. The amount of displacement can be earned. (b) By forming the pair of two sides 63 constituting the apex as the connecting portion 62 so that the wall thickness decreases as the distance from the connecting portion 62 increases, the stress applied to the two sides 63 serving as a beam is dispersed, Even larger displacements can be prevented from being damaged. (c) Since the pair of sides 64 that connect the vertices that do not constitute the connecting portion 62 are side portions and are portions where stress is concentrated, the wall thickness is sufficiently larger than the minimum value of the wall thickness of the side 63. By forming it large, damage due to stress concentration can be prevented.

  The present invention has been described above by taking the embodiment as an example. However, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way. Hereinafter, modifications will be described.

  1 and 2, only one end portion of the conductive cylindrical tube into which the contact pin is inserted is caulked, and the protrusion of one plunger portion is restricted, but the both end portions of the tube are caulked up and down. It is good also as a structure which controls both protrusions of the plunger part.

It is embodiment of the contact pin which concerns on this invention, and a contact probe provided with this, Comprising: It is a front sectional view which shows the state before the contact to test object. It is a front sectional view which shows the state after the contact to a test object similarly. It is an enlarged front view of the spring part of the contact pin in an embodiment. FIG. 4A is a perspective view showing a ring shape as a basic element of the spring portion, wherein FIG. 5A is a stress distribution when the ring wall thickness is constant, and FIG. It is a front sectional view of a contact probe of a conventional example. It is an enlarged front view which shows the spring part integral with the contact pin of another prior art example (patent document 1).

Explanation of symbols

1,20 Contact probe 2 Barrel 3,4 Plunger 5 Spring 6,80 Insulating housing 10 Circular ring 30 Contact pin 40, 50 Plunger
60 Spring part 61 Ring 62 Connection part 63, 64 Side 70 Tube 95 Inspection object

Claims (5)

In the contact pin in which the plunger part and the spring part are integrally formed of a conductive material,
The spring portion is formed by connecting a plurality of rings with a pair of opposing vertices of a hexagonal ring as a connecting portion,
A contact pin in which a pair of two sides constituting the apex as the connecting portion is curved inward of the ring.   2. The contact pin according to claim 1, wherein a pair of sides connecting apexes that do not constitute the connecting portion are curved outward of the ring. 3.   3. The contact pin according to claim 1, wherein a pair of two sides constituting an apex as the connecting portion are formed such that a wall thickness decreases as the distance from the connecting portion increases.   4. The contact pin according to claim 3, wherein a wall thickness of a pair of sides connecting apexes that do not constitute the connecting portion is larger than a minimum value of a wall thickness of a pair of two sides constituting the apex as the connecting portion. The contact pin is formed on.   A contact probe, wherein the contact pin according to any one of claims 1 to 4 is inserted into a conductive tube, and a distal end portion of the plunger portion projects from the tube end.

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