JP2008032620A - Probe pin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently stabilize a contact resistance between a wafer and a probe pin and reduce it. <P>SOLUTION: A base 40 and two contactors 41, 42 facing each other are formed at the top of end of the probe pin 10. The contactors 41, 42 are connected to the lower end of the base 40 and are formed so that the contactors come close to each other as the top end comes away from the base 40. The contactors 41, 42 bend, when pushed by the wafer, to the inside and move towards a direction to which the contactors approach each other. Thus, an oxide film on an electrode is scrub-removed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a probe pin for contacting an object to be inspected and inspecting electrical characteristics of the object to be inspected.

  For example, inspection of electrical characteristics of electronic elements such as ICs and LSIs formed on a semiconductor wafer is usually performed using a probe device. The probe device has a probe card, and a large number of probe pins are supported on the lower surface side of the probe card. The inspection of the electrical characteristics of the wafer is performed by bringing a large number of probe pins into contact with a plurality of electrode pads of an electronic element and sending and receiving electrical signals between the probe pins and the electrode pads.

  Usually, a highly insulating oxide film is formed on the surface of the electrode pad before inspection. For this reason, at the time of inspection, the probe pin is pressed strongly against the electrode pad in the vertical direction to penetrate the oxide film, or the probe pin is moved in the horizontal direction to scrub the oxide film to remove the electrical contact between the probe pin and the electrode pad. Continuity is planned.

  By the way, the types of probe pins are roughly classified into vertical probe pins that are long in the vertical direction (see Patent Document 1) and so-called cantilever type probe pins that are cantilever beams (see Patent Document 2). In the case of the vertical type probe pin, since it is inserted through the vertical through hole of the probe card, the movement in the horizontal direction is restricted, and it is difficult to remove the scrub of the oxide film. For this reason, for example, as proposed in Patent Document 1, an arcuate blade is formed at the tip of the probe pin, and the probe pin is pressed against the electrode pad so as to bite in the vertical direction, thereby energizing the probe pin and the electrode pad. Has been.

JP 2001-50979 A JP 2006-1119024 A

  However, in this case, for example, when a relatively hard oxide film such as an aluminum oxide film is formed on the electrode pad, the probe pin blade does not sufficiently penetrate into the oxide film, and the contact resistance between the probe pin and the electrode pad The contact resistance value was not stable. For this reason, the electrical contact between the probe pin and the electrode pad has not been sufficiently and stably performed.

  By the way, in the case of a so-called cantilever type probe pin, the tip of the probe pin is moved in the horizontal direction to scrub the oxide film, so that the oxide film removal capability is superior to the vertical type probe pin. However, in the case where particles accidentally exist on the tip of the probe pin contactor or on the electrode pad of the wafer facing the tip, the electrical contact between the probe pin and the electrode pad is not performed. The certainty of contact was not sufficient.

  The present invention has been made in view of this point, and an object thereof is to sufficiently and stably perform electrical contact between an object to be inspected such as a wafer and probe pins.

  In order to achieve the above object, the present invention provides a probe pin for inspecting the electrical characteristics of an object to be inspected in contact with the object to be inspected. A contact is formed, and the plurality of contacts are bent inward and moved in directions in which their tips approach each other when pressed by the object to be inspected.

  According to the present invention, since a plurality of contacts can move and the oxide film on the surface of the object to be inspected can be scraped, the oxide film can be scrubbed sufficiently stably, and the contact between the probe pin and the contact can be achieved. The resistance can be sufficiently and stably reduced. In addition, since the inspection is performed by bringing a plurality of contacts into contact with the object to be inspected, the reliability of the contact between the probe pin and the object to be inspected can be significantly improved.

  The tip of the probe pin may have a base, and the plurality of contacts may be formed such that rear ends thereof are connected to the base, respectively, and the tips end closer to each other as they move away from the base.

  A stopper for maintaining the distance between the tips of the plurality of contacts may be formed inside the contact.

  A vertical surface may be formed inside the tip of each contact, and a recess may be formed on the vertical surface.

  Two contacts may be provided. The probe pin may be a vertical type.

  According to the present invention, since the contact resistance between the probe pin and the object to be inspected is sufficiently and stably kept low, the electrical characteristics of the object to be inspected can be inspected stably with high accuracy.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is a side view showing an outline of the configuration of a probe apparatus 1 in which a probe pin according to the present invention is used.

  The probe device 1 is provided with, for example, a probe card 2 and a mounting table 3 on which a wafer W as an object to be inspected is mounted. The mounting table 3 is movable in the vertical direction and the horizontal direction.

  The probe card 2 includes, for example, a support plate 11 that supports a plurality of probe pins 10 and a circuit board 12 that sends and receives electrical signals to the probe pins 10. The support plate 11 is formed in a disk shape, for example, and faces the lower mounting table 3. In the support plate 11, for example, as shown in FIG. 2, a plurality of guide holes 20 having a rectangular horizontal cross section are formed.

  As shown in FIG. 3, each guide hole 20 penetrates the support plate 11 in the vertical direction, and a vertical probe pin 10 that is long in the vertical direction is inserted into each guide hole 20.

  The probe pin 10 includes, for example, a lower tip portion 30, a spring portion 31 connected to the upper portion, and a rear end portion 32 of the upper portion.

  The rear end portion 32 of the probe pin 10 is disposed on the upper end surface of the guide hole 20 and is formed larger than the diameter of the guide hole 20. The upper surface of the rear end portion 32 is formed flat and is in contact with the lower surface terminal 12 a of the circuit board 12 and is electrically connected to the circuit board 12. A step portion 32 a is formed on the peripheral portion on the lower surface side of the rear end portion 32, and the step portion 32 a is locked to the upper end surface of the guide hole 20, whereby the probe pin 10 is supported by the support plate 11. Yes.

  The spring portion 31 has, for example, a strip-like corrugated shape that is continuous in the vertical direction, and has elasticity in the vertical direction. The upper end of the spring portion 31 is connected to the lower surface of the rear end portion 32, and the tip portion 30 is connected to the lower end of the spring portion 31.

  The distal end portion 30 is composed of, for example, a base portion 40 and two contacts 41 and 42. The base 40 has a substantially rectangular flat plate shape, and the horizontal width of the base 40 is slightly smaller than the diameter of the guide hole 20. Thereby, the base 40 moves up and down along the inner wall of the guide hole 20, and functions as a guide for the probe pin 10 in the guide hole 20.

  The two contacts 41 and 42 are formed in, for example, a flexible elongated needle shape. The contacts 41 and 42 are connected to the lower surface of the base 40. The contacts 41 and 42 are formed from both end portions of the lower surface of the base portion 40 toward an obliquely downward direction on the center side. That is, the contacts 41 and 42 are formed so that the rear ends thereof are connected to both end portions of the lower surface of the base portion 40, and the tip ends gradually approach as the distance from the base portion 40 increases. These contacts 41 and 42 protrude below the guide hole 20.

  As shown in FIG. 4, the tips of the contactor 41 and the contactor 42 face each other with a predetermined distance therebetween. A vertical surface 41a is formed inside the tip of the contact 41, and a concave portion 41b is formed on the top of the vertical surface 41a. A stopper 41c protruding inward from the vertical surface 41a is formed above the recess 41b. The tip of the contact 42 is also provided with a vertical surface 42 a, a recess 42 b, and a stopper 42 c like the contact 41. The vertical surface 42a, the concave portion 42b, and the stopper 42c of the contact 42 are opposed to the vertical surface 41a, the concave portion 41b, and the stopper 41c of the contact 41, respectively. In addition, the probe pin 10 concerning this Embodiment is shape | molded, for example by the LIGA process (X-ray lithography, electroforming, the fine component manufacturing process by a mold).

  Next, the operation of the probe pin 10 configured as described above will be described. When the inspection of the electrical characteristics of the wafer W is started in the probe device 1, the wafer W on the mounting table 3 is raised, and each electrode pad P on the wafer W contacts each probe pin 10 as shown in FIG. It contacts the children 41, 42.

  Then, when the wafer W is further raised and the electrode pad P is pressed against the probe pin 10, the contacts 41 and 42 are bent inward as shown in FIG. Move inward while rubbing the surface. At this time, the oxide film on the surface of the electrode pad P is scrubbed and removed by the contacts 41 and 42. And if the front-end | tips of the contactors 41 and 42 adjoin, stopper 41c, 42c will contact | abut, and the movement to the inner side of the contactors 41 and 42 will be stopped. At this time, the distance between the vertical portion 41a of the contact 41 and the vertical portion 42a of the contact 42 is maintained at, for example, 10 μm or more, and a space H is formed between the recesses 41b and 42b.

  Thereafter, an electrical signal is sent from the circuit board 12 of the probe card 2 to the electrode pad P of the wafer W through the two contacts 41 and 42 of each probe pin 10, and the electrical characteristics of the wafer W are inspected.

  According to the above embodiment, the two contacts 41 and 42 facing each other are formed on the tip portion 30 of the probe pin 10, and the contacts 41 and 42 are pressed against the electrode pad P of the wafer W. In this case, the tip is bent inward and the tip moves inward on the surface of the electrode pad P. As described above, the oxide film on the surface of the electrode pad P can be removed by scrubbing using the two contacts 41 and 42 even though the probe pin 10 is a vertical type, and the contact resistance between the probe pin 10 and the electrode pad P can be reduced. It can be lowered sufficiently and stably. Further, since electrical signals are sent through the two contacts 41 and 42 of each probe pin 10 at the time of inspection, the reliability of electrical continuity between the probe pin 10 and the electrode pad P is increased, and the reliability of the inspection is increased. Sexually can be improved.

  The stoppers 41c and 42c are formed inside the tips of the contacts 41 and 42, and the distance between the tips of the contacts 41 and 42 is maintained. Therefore, oxidation during scrubbing is performed between the tips of the contacts 41 and 42. It is possible to prevent film scraps from being caught. As a result, for example, it is possible to prevent the contact resistance of the probe pin 10 from increasing due to oxides adhering to the contacts 41 and 42. Further, contamination of the wafer W by particles can be prevented. Further, the distances (slip width) by which the contacts 41 and 42 move on the surface of the electrode pad P during scrubbing are fixed by the stoppers 41c and 42c, and the slip width is accurately defined. Therefore, the displacement width of the contacts 41 and 42 is not increased more than necessary, and excessive scrub can be suppressed. As a result, generation of extra particles can be suppressed. Further, the wear of the contacts 41 and 42 is small, and the life of the probe pin 10 can be extended. In order to sufficiently remove the oxide film by scrubbing, it is sufficient that the gap width is 5 μm or more.

  Further, since the recesses 41b and 42b are formed inside the tips of the contacts 41 and 42, when the tips of the contacts 41 and 42 come close to each other, a space H is formed between them. It is possible to prevent the scrap of the oxide film from being sandwiched between the tips of 42.

  In general, a vertical probe pin does not require a mounting space as compared with a so-called cantilever type probe pin, so that it is possible to reduce the pitch and increase the number of pins in the probe card 2. Therefore, according to the vertical probe pin 10 of the present embodiment, the number of pins is further increased while ensuring sufficient and stable electrical contact between the probe pin 10 and the electrode pad P as described above. The pitch can be reduced.

  In the above embodiment, the present invention is applied to a vertical type probe pin. However, the present invention may be applied to a so-called cantilever type probe pin 10 of a cantilever as shown in FIG. Also in this case, scrub removal is performed by the two contacts 41 and 42 and electrical conduction is achieved by the two contacts 41 and 42. Therefore, the electrical connection between the contacts 41 and 42 and the electrode pad P is achieved. The certainty of contact can be increased. Further, since the gap width of each contact 41, 42 can be reduced, the wear of the contacts 41, 42 is reduced, and the life of the probe pin 10 can be extended.

  In the above embodiment, the number of contacts of the probe pin 10 is two. However, the number is not limited to two, and may be three or more. In this case, for example, as shown in FIG. 8, the base 50 at the tip of the probe pin is formed in a three-dimensional cylindrical shape, for example, and a plurality (three in FIG. 8) of opposing contacts 51 on the lower surface of the base 50. May be formed.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be made within the scope of the ideas described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs. For example, in the above embodiment, the stoppers 41c and 42c are formed on the contacts 41 and 42, but the stoppers 41c and 42c may not be provided. In this case, for example, since the contacts 41 and 42 come into contact with each other during scrubbing and serve as a stopper, the gap width of the contacts 41 and 42 is limited to an appropriate distance, and generation of extra particles can be suppressed, for example. Moreover, the lifetime of the probe pin 10 can be lengthened. For example, the contact of the probe pin 10 may have another shape as long as the contact is deflected inward when the wafer W is pressed against the wafer W and the tips are displaced in a direction approaching each other. Moreover, parts other than the contact of the probe pin 10 may have other shapes. The present invention can also be applied to the case where the object to be inspected is another substrate such as an FPD (flat panel display) other than the wafer W.

  The present invention is useful for sufficiently and stably reducing the contact resistance between an object to be inspected and a probe pin.

It is a side view which shows the outline of a structure of a probe apparatus. It is a top view of a support plate. It is a longitudinal cross-sectional view of the support plate which shows a mode that the probe pin was inserted in the guide hole. It is an enlarged view of the tip of a probe pin. It is an enlarged view of the front-end | tip of a probe pin when a wafer contacts. It is an enlarged view of the tip of a probe pin when pressed by a wafer. It is a side view of a cantilever type probe pin. It is a perspective view of the tip of a probe pin at the time of providing three contacts.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Probe apparatus 2 Probe card 10 Probe pin 11 Support plate 20 Guide hole 30 Tip part 41, 42 Contactor P Electrode pad W Wafer

Claims (6)

A probe pin for inspecting the electrical characteristics of the test object in contact with the test object,
A plurality of contacts facing each other are formed at the tip of the probe pin,
The probe pins, wherein the plurality of contacts are bent inward and moved in directions in which the tips approach each other when pressed by the object to be inspected. The tip of the probe pin has a base,
2. The probe pin according to claim 1, wherein the plurality of contacts are formed such that rear ends thereof are respectively connected to a base portion, and tip ends thereof are closer to each other as the distance from the base portion is increased. The probe pin according to claim 1 or 2, wherein a stopper for maintaining a distance between the tips of the plurality of contacts is formed inside the contact. The probe pin according to any one of claims 1 to 3, wherein a vertical surface is formed inside a tip of each contact, and a concave portion is formed on the vertical surface. The probe pin according to claim 1, wherein there are two contacts. The probe pin according to claim 1, wherein the probe pin is a vertical type.

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