JP2004170275A - Probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly precise fine microprobe of high performance capable of obtaining excellent continuity for even an electrode pad arrayed with fine pitches, and having enhanced electric contact, in the probe contacting with the electrode pad of a semiconductor device. <P>SOLUTION: This probe 13 has a probe part 1 having in its tip a contact part 4 contacting with the electrode pad 2, a needle strut 7 supporting the probe part 1 substantially right-angledly at one end, and a connection terminal part 6 connected to a substrate 5 in the other end of the strut 7. At least one sheet of conductive sub-probe part(s) 8, 9 supported substantially right-angledly to the strut 7, and arranged substantially in parallel along the probe part 1 is provided between the probe part 1 and the connection terminal 6, and the tip of the probe part 1 is constituted to contact with tips of the sub-probes 8, 9 in overdrive where the contact part 4 contacts with the electrode pad 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a probe of a probe card for measuring various electrical characteristics of a semiconductor device such as an LSI chip.
[0002]
[Prior art]
A probe of a probe card for measuring various electrical characteristics of a semiconductor device such as an LSI chip is brought into pressure contact (overdrive) with an electrode pad of the semiconductor device. 2. Description of the Related Art Semiconductor devices are becoming more highly integrated, the number of electrodes is further increased, and the spacing between the electrodes is also fine. Future probe cards are strongly required to respond to improvements in high precision, fine pitch, high frequency characteristics, and the like. On the other hand, a probe of a conventional probe card has a probe configured as a cantilever needle having a contact portion at the tip of a single probe portion to contact an electrode pad of an object to be measured such as a semiconductor device at the tip. (See Patent Document 1).
[0003]
FIG. 5 is a conceptual diagram showing a cross-sectional structure of a probe card including a conventional probe. In FIG. 5 similar to that disclosed in Patent Document 1, a probe 50 having a cantilever type needle has one conductive probe portion 51 made of an elastic body arranged substantially horizontally. At one end of the probe part 51, there is a contact part 52 having a tip part 55 whose tip makes contact with an electrode pad 56 of an object to be measured (not shown), and the other end is connected to a substrate 53 such as a printed wiring. Terminal portion 54 is provided. The probe part 51 is formed of a single elastic body, and has a shape having a length L and a thickness t. In the prior art shown in FIG. 5, in order to realize a probe card corresponding to the electrodes arranged at a fine pitch, the shape of the finely arranged probes 50 is becoming smaller and smaller, and therefore, the probe unit composed of the one piece described above is used. It is necessary to set the length L of the shape 51 shorter.
[0004]
[Patent Document 1]
Patent Publication No. 3058919 [0005]
[Problems to be solved by the invention]
In the probe according to the prior art described above, the shape of the probe to be disposed is reduced when the probe corresponding to the electrode pads arranged at the fine pitch of the measurement object is pursued. It is necessary to set the length L of the leaf spring shorter. However, if the length of the single-plate leaf-spring-like probe is reduced, the pressure due to contact increases, the stress also increases, and the stress may exceed the stress limit of the material. On the other hand, conventionally, if the thickness of the probe part is reduced in order to reduce the stress in a single probe part with the above length shortened, the contact pressure is extremely reduced and the necessary pressure is secured. You can't do that. Due to the decrease in contact pressure, it is not possible to obtain good conduction with the electrode pads arranged in a fine pitch, electrical contact deteriorates, accurate measurement of characteristics becomes impossible, and fine pitch There is a problem that adaptation to a probe card is difficult.
[0006]
The present invention provides a probe in contact with an electrode pad of a semiconductor device, which can obtain good conduction even with an electrode pad arranged at a fine pitch, and has high precision and high performance with improved electrical contact. It is an object of the present invention to provide a small and small probe.
[0007]
[Means for Solving the Problems]
In order to solve this problem, the probe of the present invention, as a means for solving the problem, a probe portion having a contact portion at the tip for contacting the electrode pad, a needle support supporting the probe portion at one end at a substantially right angle, A probe having a connection terminal portion for connecting to a substrate at the other end of the needle support, between the probe portion and the connection terminal portion, supported at substantially a right angle to the needle support, and At least one conductive sub-probe section disposed substantially in parallel along the sub-probe section so that the tip of the probe section and the tip of the sub-probe section are in contact with each other when the contact section contacts the electrode pad during overdrive. Is what you do.
[0008]
More specifically, the probe section and the sub-probe section are configured to be leaf spring-like elastic bodies.
[0009]
More specifically, the sub-probe section is configured to be shorter than the probe section.
[0010]
Further, specifically, a configuration is provided in which a conductive convex portion is provided at the tip of the sub-probe portion toward the probe portion side.
[0011]
More specifically, the tip of the probe portion and the tip or the convex portion of the sub-probe portion are configured such that at least when the contact portion is not in contact with the electrode pad, there is a gap between them. More specifically, the probe is configured and formed integrally.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 is a conceptual diagram showing a partial cross-sectional structure of a probe card including a probe according to an embodiment of the present invention. In FIG. 1, a probe portion 1 made of a conductive, leaf-spring-like elastic body is formed from a material such as Ni (nickel) having a large Young's modulus and subjected to gold plating. According to the arrangement of the fine electrode pads, the length of the probe portion 1 is shorter than that of the conventional one, and the thickness t is thinner. At one end of the probe section 1, a contact section 4 having a tip section 3 for conducting contact with an electrode pad 2 of an object to be measured (not shown) is provided. A needle support 7 for supporting the probe 1 is formed at right angles or substantially at right angles to the other end of the probe 1. The needle support 7 and the substrate 5 are connected by a connection terminal 6. In FIG. 1, the needle support 7 and the probe unit 1 are arranged at right angles or substantially at right angles to each other, and the probe unit 1 is provided substantially horizontally. The angles of these arrangements may be changed in design. Next, in FIG. 1, the plate surfaces of the leaf springs are supported between the probe unit 1 and the connection terminal unit 6 at a right angle or a substantially right angle to the needle support column 7, and are arranged substantially parallel to the probe unit 1. The probe 13 is formed by forming the two sub-probe portions 8 and 9 arranged so as to have a gap d between at least the front end 17 and the front end 16 of the probe portion. In FIG. 1, the sub-probe portions 8 and 9 are configured to have the same stress as the probe portion 1 with the thickness t. Although two sub-probes are provided, at least one sub-probe may be provided.
[0014]
The sub-probe sections 8 and 9 are formed of a conductive plate spring-like elastic body made of a material such as Ni (nickel) having a large Young's modulus and plated with gold. Here, the probe 13 including the contact part 4 having the tip part 3, the probe part 1, the sub-probe parts 8, 9 and the needle support 7, and the connection terminal part 6 is formed by a conventional technique such as electroforming, vapor deposition, and photolithography. Is created by combining.
[0015]
The probe 13 of FIG. 1 is configured such that the tip 16 of the probe 1 and the tip 17 of the sub-probes 8 and 9 come into contact with each other at the time of overdrive in which the tip of the contact portion 4 contacts the electrode pad 2. It is assumed that the tip of the contact portion 4 having the tip portion 3 contacts the electrode pad 2, the probe 13 is overdriven, and the stylus pressure is 1 g when the stroke of the probe portion 1 is 100 μm. In the case of the conventional probe in which only one thin probe portion having the same stress with the same thickness t as the probe portion 1 is formed, the stylus pressure that the probe can output is 1 g. In FIG. 1, the overdrive proceeds with each gap d being 5 μm, and the stroke of the sub-probe section 8 having the same stress as the probe section 1 is 95 μm, so that the stylus pressure by the sub-probe section 8 is about 0.95 g. Further overdrive proceeds, and the stroke of the sub-probe section 9 having the same stress as the probe section 1 becomes 90 μm, so that the stylus pressure by the sub-probe section 9 becomes about 0.9 g. At the end of the overdrive, in the probe 13 provided with the two sub-probe portions 8 and 9 in addition to the probe portion 1, the total needle pressure applied to the electrode pad 2 becomes 2.85 g, and the stress due to the same thickness t Thus, the stylus pressure can be remarkably increased from 1 g of the stylus pressure of a conventional probe having a single probe unit having the above, and the conductive contact can be stably performed even with a fine electrode pad arrangement.
[0016]
Above, by generating the needle pressure by the combined force of a plurality of leaf springs composed of the probe supported by the needle support and at least one sub-probe, even if the probe has the same stress as before, As a result, a sufficiently high needle pressure can be secured, good conduction can be obtained even with a fine electrode pad arrangement, and electrical contact can be improved.
[0017]
Further, even when the length L of the probe portion is designed to be short, a large needle pressure is generated by the resultant force of a plurality of leaf springs including the probe portion supported by the needle support and at least one sub-probe portion. Since a sufficient stylus pressure can be secured, it is possible to make the probe minute and small and compact, and it is easy to apply the probe to a fine pitch probe card corresponding to a fine pitch electrode pad.
[0018]
Further, by generating a needle pressure by a resultant force of a plurality of leaf springs composed of a probe portion supported by a needle support and at least one sub-probe portion, the pressure of each of the leaf springs constituting the same is lower than that of a conventional product. Since the stress can be reduced by reducing the thickness t of the leaf spring alone, it is possible to improve the durability of the probe.
[0019]
FIG. 2 is a conceptual diagram showing a cross-sectional structure of a probe which is another example of the embodiment of the present invention. 1 are given the same reference numerals. 2 differs from FIG. 1 in that the lengths of the two sub-probe sections 10 and 11 supported by the needle support 7 of the probe 14 are slightly shorter than the probe section 1, and the sub-probe section 10 , 11 are provided with a conductive convex portion 12 toward the probe portion 1 side. Further, the convex portion 12 of the sub-probe portion has at least the distal end portion 3 of the contact portion 4 which is not in contact with the electrode pad 2. Sometimes, there is a gap s between the tip 16 of the probe unit 1. The convex portion 12 may have a convex shape or may be formed by partially bending the tip of the sub-probe portion, and when pressed, the convex portion 12 of the sub-probe portion may be formed by the probe portion 1 or another sub-probe portion. Any convex shape may be used as long as it can contact the surface.
[0020]
FIG. 3 is a conceptual diagram showing the operation of the probe according to the embodiment of FIG. In FIGS. 2 and 3, when the distal end portion 3 of the contact portion 4 of the probe 14 comes into contact with the electrode pad 2 and is further pressed during overdrive, the conductivity of the sub-probe portion 10 shorter than the probe portion 1 is reduced. When the protruding portion 12 of the sub-probe portion 1 is in conductive contact with the tip 16 of the probe portion 1 and further pressed, the conductive protruding portion 12 of the sub-probe portion 11 having a shorter length than the sub-probe portion 10 Conducting contact with At this time, assuming that the conventional conductor resistance value of only one probe unit is 1Ω, the probe 14 in FIG. .33 Ω, and the electrical conduction characteristics are improved.
[0021]
In the above, since the length of the sub-probe is shorter than the length of the probe, at the end of the overdrive, the tip of the probe and the tip of the sub-probe are connected almost aligned, and the tip of the sub-probe is connected. Does not protrude from the tip of the conductive probe portion. Also, at the end of overdrive, the tip of the sub-probe section is made convex so that contact pressure is concentrated on the tip, and the area of the contact section is reduced, thereby preventing the entry of dust and the like. Therefore, the conductive contact can be made even better, the current capacity per probe can be increased, and the electrical conduction characteristics are improved.
[0022]
In addition, by making the length of the sub-probe portion provided with a conductive convex portion at the tip shorter than the probe portion and having a gap between the probe portion and the probe portion, the stylus pressure of the probe during overdrive is reduced. Since it gradually increases, it functions like a shock absorber, and the impact resistance of the probe when it comes into contact with the electrode is further improved.
[0023]
FIG. 4 is a conceptual diagram showing a cross-sectional structure of a probe which is another example of the embodiment of the present invention. The same components as those in FIG. 2 are denoted by the same reference numerals. 4 differs from FIG. 2 in that the probe 20 separates the contact portion 4 having the tip 3, the probe portion 1, the sub-probe portions 10 and 11, the needle support 7, and the connection terminal portion from each other. Rather than being integrally formed. Using a material such as Ni (nickel) having a large Young's modulus, it is formed in an integrated structure by combining electroforming, vapor deposition, photolithographic etching technology, and gold plating technology.
[0024]
As described above, a probe with high accuracy can be obtained without increasing the number of steps by integrally forming and forming the probe.
[0025]
Although the above description has been made assuming that the needle support is formed, the same applies to the case where the shape is such that the needle support is only a little, and the probe support and the sub-probe are supported at the root of the connection terminal portion. Can be implemented.
[0026]
In the above description, the thicknesses of the probe portion and the sub-probe portion are set to be the same, and the gaps between them are set to be the same.
[0027]
In the above description, the probe portion and the sub-probe portion are formed using the same material. However, even if the probe portion and the sub-probe portion having different materials and different stresses are formed in combination, the number of steps increases. However, it is possible to improve performance such as improvement of the probe pressure and miniaturization of the shape of the probe.
[0028]
Further, in the above, the length of the sub-probe section is shorter than the probe section, and the probe section and the sub-probe section are described as having a gap, but the probe section and the sub-probe section have the same length, Further, the present invention can be similarly implemented even when there is almost no gap between the probe portion and the sub probe portion.
[0029]
【The invention's effect】
As described above, according to the present invention, a needle pressure is generated by a resultant force of a plurality of leaf springs each including a probe portion supported by a needle support and at least one sub-probe portion. However, a sufficiently high stylus pressure can be ensured as compared with the related art, and good conduction can be obtained even with a fine electrode pad arrangement, and electrical contact can be improved.
[0030]
Further, even if the length L of the probe portion is designed to be short, sufficient needle pressure can be secured, so that the probe can be made minute and small, and can be easily applied to a fine pitch probe card. become.
[0031]
Further, the pressure of each of the leaf springs constituting the probe can be smaller than that of the conventional product, and the thickness t of the leaf spring itself can be reduced to reduce the stress, so that the durability of the probe can be improved. Become.
[0032]
As described above, by making the length of the sub-probe portion shorter than that of the probe portion, at the end of the overdrive, the front end of the probe portion and the front end of the sub-probe portion are almost aligned and connected. Does not protrude from the tip of the conductive probe portion. In addition, by providing a conductive convex portion at the tip of the sub-probe portion, at the end of overdrive, contact pressure is concentrated on the tip, and the conductive probe portion and the sub-probe portion having the convex portion have better conductive contact. Therefore, the current capacity of each probe can be increased, and the electrical conduction characteristics are improved.
[0033]
Also, by providing a gap between the probe and the tip of the sub-probe or the protrusion, the stylus pressure of the probe gradually increases during overdrive, so that it serves as a shock absorber. As a result, the impact resistance at the time of electrode contact is further improved.
[0034]
In addition, a probe with high accuracy can be obtained without increasing the number of steps by integrally forming and forming the entire probe.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram illustrating a partial cross-sectional structure of a probe card including a probe according to an embodiment of the present invention. FIG. 2 is a conceptual diagram illustrating a cross-sectional structure of a probe according to another embodiment of the present invention. FIG. 3 is a conceptual diagram showing the operation of the probe of the embodiment of FIG. 2; Conceptual diagram showing cross-sectional structure of probe card including
DESCRIPTION OF SYMBOLS 1 Probe part 2 Electrode pad 3 Tip part 4 Contact part 5 Substrate 6 Connection terminal part 7 Needle support 8, 9, 10, 11 Sub-probe part 12 Convex part 13, 14, 20 Probe 16, 17 Tip L Length t Thickness d, s gap

Claims (6)

A probe portion having a contact portion at the tip for contacting the electrode pad, a needle post supporting the probe portion at a substantially right angle at one end, and a connection terminal portion for connecting the needle post to a substrate. A probe, between the probe portion and the connection terminal portion, at least one conductive sub-portion supported at substantially a right angle to the needle support and disposed substantially parallel along the probe portion; A probe provided with a probe portion, such that a tip of the probe portion and a tip of the sub-probe portion are in contact with each other during overdrive in which the contact portion contacts the electrode pad. The probe according to claim 1, wherein the probe unit and the sub-probe unit are configured as a leaf spring-shaped elastic body. The probe according to claim 1, wherein the sub-probe section is configured to be shorter than the probe section. The probe according to any one of claims 1 to 3, wherein a conductive protrusion is provided on the tip of the sub-probe section toward the probe section. 5. The device according to claim 1, wherein the tip of the probe unit and the tip or the protrusion of the sub-probe unit have a gap between them at least when the contact part is not in contact with the electrode pad. The probe according to any one of the above. The probe according to any one of claims 1 to 5, wherein the probe is configured and formed integrally.

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