JP2007271631A - Probe card for wafer test - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a probe card capable of acquiring stable electric contact with a test pad, concerning a vertical type probe card. <P>SOLUTION: This probe card for a wafer test for testing operation of a semiconductor wafer 100 by pressing the tip part 1a of a probe needle 1 mounted approximately vertically to a substrate onto an electrode pad 100a of the semiconductor wafer 100 is disclosed as follows: as for the probe needle 1, a root side part and the tip part 1a of the probe needle 1 are held respectively by a guide plate; the root side part and a center part have each smaller diameter compared with the diameter of the tip part 1a; the tip shape of the probe needle 1 is formed as an approximately spherical shape having a radius of curvature of 7-30 microns; shear is generated in the electrode pad 100a by contact with the electrode pad caused by pressing; and, as for a guide hole 4a on the guide plate 4 for holding the tip part 1a of the probe needle 1, the diameter of the guide hole 4a is changed into a tapered shape in the longitudinal direction, and the minimum diameter is approximately the same as the diameter of the tip part 1a of the probe needle 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer test probe card, and more particularly to a vertical probe card for measuring electrical characteristics of a semiconductor integrated circuit and a liquid crystal display device.

  In recent years, with the high integration of semiconductors, the number of terminals (bonding pads) constituting the semiconductor has increased, and the number of electrode pads per chip tends to increase. As a wafer test probe card for measuring electrical characteristics of a semiconductor integrated circuit or a liquid crystal display device, conventionally, a probe needle is horizontally arranged, and the tip of the probe needle is bent at a right angle so that the tip of the probe needle contacts a test pad. A cantilever probe card was used. In this type of probe card, the end of the probe needle made of a tungsten needle tapered so as to become gradually thinner toward the tip is attached almost horizontally to the substrate, and the tip is bent substantially at a right angle. The tip is configured to contact the bonding pad. However, the above-described cantilever method cannot cope with an increase in the number of bonding pads or a reduction in pad pitch. In response to such an increase in the number of pads and a reduction in pad pitch, semiconductor operation test technology (probe card assembly technology) is also required, and a structure that can increase the number of probe needles and the needle stand density of the probe card is devised. There is a need. As a means for increasing the number of probe needles of the probe card, a vertical probe card is proposed in which ultra-fine probe needles that can be elastically deformed are mounted substantially perpendicular to the semiconductor to be measured. By arranging the probe needle vertically, the horizontal portion of the probe needle in the conventional cantilever system is eliminated, so that the structure of the probe card can be simplified and the needle stand density can be improved. However, there are some problems with this vertically arranged probe card, and various ideas have been made for this problem.

For example, in the method disclosed in Japanese Patent Application Laid-Open No. 64-35382, as shown in FIG. 8, the tip portion of the probe needle 10 fixed to the fixed substrate 11 with an adhesive 11a or the like is attached to two guide plates 12, 13 and a method of maintaining the perpendicularity to the object to be measured while increasing the positioning accuracy by restraining the tip of the probe needle by slightly sliding the positions of the guide plates 12 and 13 with each other. .
The above-described method of designating the probe needle tip position with the guide plate is also described in JP-A-6-82481, JP-A-8-285890, and the like.

  However, in the method disclosed in Japanese Patent Laid-Open No. 64-35382, the probe needle tip portion is restrained by relatively displacing the two guide plates at the probe needle tip portion, so that the positional accuracy of the probe needle tip is improved. Because the movement of the tip of the probe needle is also constrained, the probe needle and the bonding pad material are less likely to slip relative to each other when contacting the semiconductor bonding pad.For example, when the bonding pad material is an aluminum alloy. In some cases, the surface oxide film is not efficiently broken, and the electrical contact resistance increases between the tip of the probe needle and the bonding material, so that the semiconductor operation test cannot be performed correctly.

  Further, in the cantilever type probe card, the reaction force generated by the contact between the probe needle and the test pad works at right angles to the longitudinal direction of the probe needle, so that the probe needle is easily bent. The relative sliding between the part and the test pad occurs with a relatively small force of about 5 to 10 g. On the other hand, in a vertically arranged probe card, the direction of the reaction force generated by the contact between the tip of the probe needle and the test pad matches the axial direction of the probe needle. In order to make the relative displacement, it is necessary to buckle the probe needle. The force for buckling the probe needle varies depending on the needle diameter of the probe needle, but is as large as 10 to 100 g. Conventionally, the probe needle needs to have a tip diameter of about 30 microns or less in consideration of the test pad opening (small, 80 micron square). When such a small needle tip contacts the test pad, There is also a problem that the test pad is destroyed because excessive contact stress is generated on the test pad. In contrast, as disclosed in Japanese Patent Application Laid-Open No. 64-35382, the probe needles for guiding and holding the root portion and the tip portion of the probe needle are displaced in the same direction in advance, respectively. An attempt has been made to reduce the contact stress by bending the probe needle in a certain direction so that the probe needle material is easily bent to facilitate relative displacement between the probe needle and the test pad. However, the probe needle manufacturing method is so-called tapered so that it gradually becomes thinner from the probe needle root part to the tip part by etching. However, since the taper process is performed, the bending stress is larger at the probe needle tip part. Therefore, even if such a probe needle is brought into contact with the test pad of the wafer by shifting the relative position of the guide plate, even if the entire probe needle is buckled and bent, the deformation concentrates on the probe needle tip, and the probe tip and the aluminum pad Rotation at the contact portion of the probe may cause a relative slip between the probe tip and the aluminum pad, or the probe needle tip may be bent.

  Further, the tip end portion of the probe needle is tapered as described above, and when the taper processing is performed, the probe needle varies in thickness. When there is a variation in the thickness of the probe needle, the thickest probe needle is strongly restrained by the two guide plates, so that the probe needle moves poorly due to friction. Furthermore, even if the holes in the guide plate are made with high accuracy, the pitch between the two holes is widened by sandwiching the thickest probe needle between the two guide plates as described above. I was unable to guide.

  In the method disclosed in Japanese Patent Laid-Open No. 6-82481, the guide plate has a three-layer structure, and the probe needle is bent by slightly shifting the guide plate provided in the middle so that the probe needle is a test pad. A method is disclosed in which the entire probe needle is buckled in one direction with a smaller force when it comes into contact with the guide. In this method, the layer structure of the guide plate is increased, and each hole of each guide plate is etched. Since the structure for supporting the probe needle is formed, the structure for holding the probe needle becomes complicated.

  Further, in Japanese Patent Laid-Open No. 8-285890, by setting the hole diameter of the guide plate on the probe needle side to be small in the two guide plates holding the probe needle, the shavings of the electrode pad to be measured do not enter. However, in this case as well, the horizontal movement of the probe needle is constrained by the two guide plates, and the relative sliding between the probe needle and the electrode pad is limited, and stable electrical contact cannot be obtained. was there.

  In this way, the vertical probe card is easy to obtain the needle stand density and the needle tip position accuracy, but the structure in which the probe needle and the test pad material are difficult to slide relative to each other, the conventional horizontal arrangement method (cantilever method) However, it is difficult to increase the needle stand density and improve the position accuracy of the tip of the probe card, but each method has advantages and disadvantages, such as relative sliding between the probe needle and the test pad material.

  The present invention has been made to solve the above-mentioned problems, and in a vertical probe card having high needle stand density and high needle tip position accuracy, it is possible to cause relative slip even at a low load. It is an object of the present invention to provide a probe card that can obtain stable electrical contact with the card.

  The probe card for wafer test according to the present invention is configured such that a tip end portion of a probe needle mounted substantially perpendicular to a substrate is pressed against an electrode pad of a semiconductor wafer, and the tip portion and the pad are brought into electrical contact with each other. In the wafer test probe card for testing the operation of the wafer, the probe needle holds the base side portion and the tip portion of the probe needle by the guide plate, and the tip of the tip portion held by the guide plate. Compared to the diameter, at least the diameter of the central part between the root side part and the tip part is configured to be thin, and the tip of the probe needle has a substantially spherical shape with a curvature radius of 7 to 30 microns, Of the guide plate that holds the tip of the probe needle by shearing the electrode pad by contact with the electrode pad by the pressing. Id holes, the diameter of the guide holes is changed in a tapered shape with respect to the longitudinal direction, the smallest diameter is not less about the same as the diameter of the tip portion of the probe needle.

According to the present invention, the tip portion of the probe needle mounted substantially perpendicular to the substrate is pressed against the electrode pad of the semiconductor wafer, and the tip portion and the pad are brought into electrical contact, thereby operating the semiconductor wafer. In the wafer testing probe card to be tested, the probe needle holds the base side portion and the tip portion of the probe needle by a guide plate, respectively, and has a diameter larger than the diameter of the tip portion held by the guide plate. The diameter of the central portion between at least the root side portion and the tip portion is made thin, and the tip of the probe needle has a substantially spherical shape with a radius of curvature of 7 to 30 microns, Since the electrode pad is sheared by contact with the pad, the main deformed portion of the probe needle becomes the central portion of the probe needle, and the probe needle Can cause rotational movement to the end portion, since the probe needles tends to relative sliding with respect to the electrode pads to be measured, electrical contact between the test pad material and the probe needles will allow stable.
Further, the guide hole of the guide plate for holding the tip portion of the probe needle has a diameter of the guide hole that changes in a taper shape with respect to the length direction, and the minimum diameter is equal to the diameter of the tip portion of the probe needle. Since they are substantially the same, it is possible to ensure the positioning accuracy and the relative slip amount with the test pad material due to the rotation of the probe needle tip.

Embodiment 1 FIG.
1 (a) and 1 (b) are configuration diagrams showing the main part of a vertical probe card according to Embodiment 1 of the present invention. FIG. 1 (a) is before buckling, and FIG. 1 (b) is buckling. It shows the later state. In the figure, 1 is a probe needle, 2 is a substrate, 3 and 4 are guide plates, 100 is a semiconductor, and 100a is a bonding pad.

Next, the operation will be described.
The probe needle 1 that is in contact with the bonding pad 100a of the semiconductor 100 to be measured is generally made of tungsten, tungsten alloy, or the like, or palladium or palladium alloy, and one end thereof is connected to a computer for testing the semiconductor. It is electrically connected and fixed to the through hole of the substrate 2 by solder 2a. Among the two guide plates 3 and 4 provided at the lower portion of the substrate 2 for guiding and positioning the probe needle 1, the guide plate 3 is a portion close to the root of the probe needle 1 (with respect to the tip portion). The side of the solder attached to the substrate (hereinafter referred to as the root side portion) 1b holds the bending stress generated by the probe needle buckling caused by the probe needle tip portion contacting the test pad. It has a role that is difficult to convey to the 2a portion. The guide plate 4 holds a portion (hereinafter referred to as a tip portion) 1a close to the tip of the probe needle 1, and has a function of holding the relative positional accuracy between the test pad and the tip portion of the probe needle. Yes.

  In the probe needle 1 in the present embodiment, the diameter of the root side portion 1b of the probe needle held by the guide plate 3 and the central portion 1c between the root side portion 1b and the tip end portion 1a is the above guide. The diameter of the tip portion 1a of the probe needle held by the plate 4 is smaller. With such a configuration, buckling deformation is easily caused, and the main buckling deformation is generated not at the probe needle tip portion 1a but at the probe needle center portion 1c, and the probe needle tip portion 1a is at the root. The tip portion 1a of the probe needle is rotationally moved relatively thicker than the side portion 1b and the central portion 1c to increase rigidity, and the test pad and the probe needle can be easily relatively slipped by this rotational motion. I am doing so.

  In order to form the probe needle 1 according to the present embodiment, the root side portion is etched by dipping the base side portion and the center portion of the probe needle material having a substantially spherical shape in a sodium hydroxide solution and applying electropolishing. And the center part can be comprised thinly compared with the front-end | tip part.

  By such a method, for example, the diameter of the probe needle tip portion 1a that contacts the hole of the guide plate 4 is set to 100 microns, and the length of the tip portion of the probe needle having the above diameter is set to 800 microns. The average diameter of the probe needle root side portion 1b and the central portion 1c was 50 microns, and the length of the probe needle root side portion and the central portion 1c having the above-mentioned diameter was 5000 microns. In this case, the bending rigidity of the tip portion is approximately 16 times that of the root portion and the center portion, and the amount of deflection of the center portion 1c when a load is applied is approximately 100 times that of the probe needle tip portion. It becomes almost rigid with respect to the root side and the central part, and the probe needle tip part contacts the semiconductor test pad, causing the probe needle center part to undergo major deformation due to buckling, and this deformation causes the tip part of the probe needle to rotate. Exercise. By this rotational movement, the probe needle tip portion and the test pad material easily slide relative to each other, and stable electrical contact can be obtained.

  Further, as described above, in order to form the probe needle according to the present embodiment, the root side portion and the central portion are made thinner than the tip portion by etching, but the central axis of the thinned central portion and the tip portion not etched are etched. The center axis does not coincide with the center axis. As a result, an offset load is generated in the center portion, so that buckling is more likely to occur in the center portion.

  Although the case where the probe needle material is tungsten or a tungsten alloy has been described as an example in the present embodiment, the probe needle material does not have to be tungsten or a tungsten alloy.

  In addition, when the probe needle material is made by sintering powder like tungsten or tungsten alloy, there are not a few vacancies. Therefore, by reducing the number of vacancies by heat treatment, Adhesion can be suppressed, and it is effective for keeping electrical contact resistance small.

  As heat treatment conditions, for example, it is effective to heat in a non-oxidizing atmosphere such as argon gas at a temperature lower than the recrystallization temperature of tungsten and to increase the pressure of the argon gas and pressurize. Usually, in order to suppress defects in the metal material, heating and pressurization at a temperature higher than the recrystallization temperature is performed. However, since tungsten or tungsten alloy has a crystal structure that becomes coarser at the recrystallization temperature or higher, the temperature exceeds the recrystallization temperature. Heat treatment cannot be performed in Therefore, it has been considered difficult to remove the vacancy defects. However, it has been found that a material having a large processing strain in the drawing process, such as a tungsten probe needle, recrystallizes even below the recrystallization temperature, and that fine vacancy defects can be eliminated by applying pressure.

  For example, the heat treatment temperature may be 300 to 600 ° C., the pressure of the non-oxidizing atmosphere may be 200 to 2000 atmospheres, and the holding time may be about 0.5 to 5 hours. In addition, it has been confirmed that recrystallization does not occur in a large-diameter wire that is not subjected to processing distortion due to wire drawing under such conditions, for example, a 5 mm diameter tungsten round bar material.

  In the above heat treatment, if the pressure limit of the apparatus is high, there is no problem even at 2000 atmospheres or more.

  In this embodiment, the defects inside the probe needle material can be almost eliminated by heat treatment at 500 ° C., 1000 atm for 1 hour, and the amount of aluminum scraps adhering to the tip of the probe needle can be drastically reduced. . Thereby, the adhesion of aluminum at the probe needle tip portion is suppressed, and the contact resistance between the probe needle tip portion and the test pad material can be kept low and stable for a long period of time.

  Further, as shown in FIG. 2, the tip of the probe needle 1 has a substantially spherical shape, and the curvature radius R of the substantially spherical shape is set to 7 to 30 microns. The contact resistance is very small. In this case, the semiconductor bonding pad 20 is formed by film formation by sputtering, and the metal crystal structure has a so-called C-axis orientation in which the metal crystal structure becomes (111) in the direction 30 perpendicular to the wafer surface. For this reason, the sliding surface when the metal is deformed has an angle of 35.3 degrees with the sliding surface 40 of the above (111), for example, in addition to the sliding surface parallel to the wafer surface 40 (111). By actively generating sliding deformation on the sliding surface 50 such as (100), the oxide film on the surface of the aluminum pad can be efficiently removed.

  For example, when the thickness of the bonding pad 20 is 0.8 micron, the bonding pad material can be smoothly shear-deformed at the tip of the probe needle and the waterline height t on the surface of the bonding pad that have been eroded by the thickness of the bonding pad. There is a condition that the angle θ at the draft portion between the pad surface and the probe needle tip surface is 17 degrees. This angle is a condition in which the sliding surfaces (111) and (100) are alternately generated, and shear deformation of the bonding pad material continuously occurs on the probe needle tip surface. Thereby, metal contact with the bonding pad material occurs on the probe needle tip surface, and stable electrical contact is realized. The curvature radius R of the tip portion of the probe needle that satisfies the angle condition at this time is 15 microns.

  Although the condition of the radius of curvature R varies depending on the thickness of the bonding pad, it has been found that good electrical contact can be obtained for a typical bonding pad thickness if R is approximately 7-30 microns.

  By using the tip-shaped probe needle having the radius of curvature R, the relative slip between the probe needle tip and the bonding pad can be minimized. For example, when the radius of curvature of the approximate spherical surface of the probe needle tip is 15 microns, a relative slip amount of about 10 microns is sufficient, and the relative slip with the test pad due to the rotation of the probe needle tip portion shown in the present embodiment is sufficient. Sufficiently stable electrical contact can be obtained.

  The probe needle 1 is held by relatively shifting the positions of the holes of the guide plates 3 and 4 so that the probe needle is curved in one direction in advance, thereby further facilitating the rotational movement due to buckling. May be.

Embodiment 2. FIG.
In the first embodiment, the base portion 1b and the center portion 1c of the probe needle are made thinner than the tip portion 1a of the probe needle, so that the center portion 1c is buckled and the tip portion 1a of the probe needle 1 is rotated. However, when the base side portion 1b and the center portion 1c of the probe needle are processed to be thin by etching, the needle diameter becomes smaller toward the root side portion, so that bending stress due to buckling deformation is applied to the probe needle 1 and the substrate 2. Therefore, since the stress is repeatedly generated in the solder connection portion due to repeated contact between the probe needle tip portion and the test pad, the solder 2a may be cracked.

  3 (a) and 3 (b) are configuration diagrams showing the main part of the vertical probe card according to the second embodiment of the present invention. FIG. 3 (a) shows a state before buckling, and FIG. 3 (b) shows a buckling. It shows the later state.

  In the probe needle 1 according to the present embodiment, the base portion 1b of the probe needle and the tip portion 1a of the probe needle are respectively opened in the guide plates 3 and 4 and held by holes. The diameter of the central portion 1c of the probe needle between the held tip portion 1a and the root side portion 1b is smaller than the diameter of the tip portion 1a and the diameter of the root side portion 1b. By adopting such a configuration, as in the first embodiment, buckling deformation is easily caused in the central portion 1c, the tip portion of the probe needle is rotated, and the bending moment due to the buckling deformation is reduced by the substrate. Therefore, the reliability of the solder connection portion can be improved. At this time, by making the clearance between the hole 3a provided in the guide plate 3 and the probe needle base side portion 1b as small as possible, the bending stress due to the buckling deformation of the probe needle 1 hardly reaches the solder connection portion.

  In order to form the probe needle 1 according to the present embodiment, as in the first embodiment, the central portion 1c is formed by etching by immersing a probe needle material having a substantially spherical tip in a sodium hydroxide solution and subjecting it to electrolytic polishing. The tip portion 1a and the root side portion 1b can be made thinner than the tip portion 1a, but at this time, the tip portion and the root side portion of the probe needle material can be coated to selectively narrow only the center portion. Can do.

Embodiment 3 FIG.
FIG. 4 is an explanatory view showing a probe needle according to Embodiment 3 of the present invention.
The probe needle 1 in the present embodiment is such that the diameter of the base side portion 1b and the center portion 1c of the probe needle held by the guide plate 3 shown in FIG. The root portion 1b and the central portion 1c are configured to be thinner than the diameter of the portion 1a, and further taper as they approach the tip portion 1a, thereby forming a “neck” at the boundary with the tip portion 1a. Since the probe needle 1 according to the present embodiment has the “necked” portion 1d having such a minimum diameter, buckling deformation greatly occurs in the “necked” portion 1d, and the tip portion of the probe needle 1 is formed. The rotational movement of 1a is more likely to occur.

In the probe needle 1 having the above-described configuration, in order for the probe needle tip portion 1a to rotate by buckling at the “neck” portion 1d, the diameter of the “neck” portion 1d is d ₂ and the diameter of the tip portion 1a is d _1. When the length of the tip portion 1a is L and the thickness of the guide plate 4 holding the tip portion 1a is h,
d ₂ / d ₁ ≦ 0.9, L / h> 1
It is desirable that That is, the “necked” portion 1d is usually formed by etching, but it is preferable to form a “necked” by providing a diameter difference of at least 10% in consideration of manufacturing variations. For example, if the diameter difference is 10%, the bending stiffness works as the fourth power of the diameter, so even if d ₂ / d ₁ = 0.9, the stiffness of the “necked” portion 1d is about 65% of the tip portion 1a, and is buckled. Can be caused.
In addition, in order for the tip portion 1a to rotate about the guide plate 4, the length L of the tip portion 1a must be greater than the thickness h of the guide plate 4 that holds the tip portion 1a. Note that h is a thickness for holding the probe tip portion 1a and does not necessarily match the thickness of the guide plate 4.

Next, a method for manufacturing a probe needle according to the present embodiment is shown in FIG.
First, as shown in FIG. 5 (a), the shape of the tip portion of the probe needle material is made into a substantially spherical shape, and the curvature radius R of the substantially spherical shape is made to be 20 μm or less. Next, as shown in FIG. 5B, the tip portion is masked. Such a probe needle material is immersed in an NaOH solution, and the probe needle material is electrolytically etched while being gradually pulled up (FIG. 5C). The probe needle material thus obtained is shown in FIG. 5 (d), and then the mask is removed to obtain a probe needle having a taper-shaped root side portion and a central portion.

  The position of the “neck” of the probe needle is most preferably provided at the boundary portion with the tip portion 1a as shown in the above embodiment, but may be provided at the central portion 1c near the tip portion 1a. , Buckling is likely to occur at the position where the “neck” is provided, and rotational movement of the tip portion is likely to occur.

  Moreover, in the said embodiment, although the taper-shaped thing which becomes thin as the base part 1b and the center part 1c approach the front-end | tip part 1a was shown for the reason on manufacture, the "constriction" part 1d is shown in the center part 1c. If it is provided, it does not have to be a tapered shape.

Moreover, the structure which provided the "constriction" in the said center part 1c may be sufficient with respect to the probe needle of the structure used in Embodiment 2 where the diameter of the base side part 1b is thicker than the diameter of the center part 1c.
At this time, the position of the “neck” is preferably provided at the boundary with the tip portion 1a or at a position close to the tip portion as in the third embodiment.

  Furthermore, although the shape of the front-end | tip part 1a showed the thing of substantially spherical shape in the said embodiment, it does not necessarily need to be spherical shape.

Embodiment 4 FIG.
In the probe needle structure shown in the first and second embodiments, since the tip portion of the probe needle rotates, it is necessary to make the diameter of the guide hole 4a of the guide plate 4 for guiding and holding the probe needle tip portion larger than that of the probe needle. There is. For example, when the probe needle tip portion 1a has a length of 800 μm and a diameter of 80 μm, the probe needle tip portion 1a has a diameter of 110 μm and the guide plate 4 has a thickness of 0.4 mm. Is about 1.4 degrees, and the relative sliding amount between the probe needle tip 1a and the test pad 100a is about 60 μm. However, in this case, the clearance between the probe needle tip portion 1a and the guide hole 4a becomes the positioning accuracy of the probe needle tip portion 1a. Further, if this clearance is reduced, the positioning accuracy is improved, but the slippage due to the rotation of the probe needle tip 1a is reduced. Accordingly, the hole shape in the guide plate 4 is devised in order to ensure the positioning accuracy and the relative slip amount with the test pad material due to the rotation of the probe needle tip.

6 (a) and 6 (b) are configuration diagrams showing the main part of the vertical probe card according to the fourth embodiment of the present invention. FIG. 6 (a) is before buckling, and FIG. 6 (b) is buckling. It shows the later state.
In the present embodiment, the hole 4a of the guide plate 4 that holds the probe needle tip portion 1a is configured such that the diameter of the hole near the center with respect to the length direction of the hole 4a is smaller than the diameters at both ends of the hole 4a. The diameter of the hole near the center is set close to the diameter of the probe needle tip 1a.

  For example, in the case of the present embodiment, the diameter of the probe needle tip 1a is 80 μm, the diameter of the hole near the center with respect to the length direction of the guide hole 4a is slightly over 80 μm, and the diameters at both ends of the hole are 110 μm. Yes. Since the thickness of the guide plate 4 is 0.4 mm, the probe needle tip portion 1a can be inclined by about 3 degrees. When the length of the probe needle tip portion 1a is about 800 μm, the probe needle tip portion 1a and the test pad 100a can slide relative to each other by about 60 μm, and a sufficient amount of sliding can be obtained to obtain electrical contact.

In the present embodiment, the diameter of both end portions of the hole is expanded as compared with the central portion, but the diameter of the hole on the test pad 100a side of the guide plate 4 is made closer to the diameter of the probe needle tip portion 1a, and the diameter of the hole on the opposite side is increased. A taper-shaped hole with an expanded width may be used.
On the other hand, a reverse tapered hole in which the diameter of the hole on the test pad 100a side of the guide plate 4 is expanded and the diameter of the hole on the opposite side is brought close to the diameter of the probe needle tip portion 1a may be used.

  In the above embodiment, the hole shape of the guide hole 4a is devised to ensure the positioning accuracy and the relative slip amount with the test pad material by the rotation of the probe needle. However, the material of the guide plate 4 is made of resin such as polyimide. If configured, the hole shape may be straight and the diameter of the tip of the probe needle and the diameter of the hole 4a may be the same, ensuring the positioning accuracy and the relative sliding amount with the test pad material due to the rotation of the probe needle. it can.

Embodiment 5 FIG.
FIG. 7 is a cross-sectional view showing the structure of guide holes in the guide plate according to the fifth embodiment.
By applying the lubricating film 5 having a small friction coefficient to the surface of the guide hole 4a of the guide plate 4 that holds and guides the probe needle portion 1a, the contact resistance between the probe needle tip portion 1a and the guide hole 4a can be reduced. .

  In the present embodiment, DLC (diamond-like carbon) is coated on the surface of the guide plate 4 and the guide hole 4a as the lubricating film 5, but the lubricating film 5 includes a probe needle tip portion 1a and a guide hole 4a. As long as the frictional resistance is reduced, a resin-type lubricant film such as a Teflon (registered trademark) coating may be used instead of the ceramic-type lubricant film such as DLC.

  In the probe needle structure according to each embodiment of the present invention, since the probe needle tip 1a rotates, friction with the guide hole 4a hardly occurs, but there is still some friction resistance, and this friction resistance is the probe resistance. It acts in a direction that hinders the rotational movement of the needle tip portion 1a. Therefore, in order to smoothly generate the rotational movement of the probe needle tip portion with a smaller force, the lubrication film 5 shown in the present embodiment is applied so that the probe needle tip portion 1a and the guide hole 4a of the guide plate 4 are provided. It is desirable to make the frictional resistance due to contact with the smallest possible.

It is a block diagram which shows the principal part of the vertical probe card by Embodiment 1 of this invention. It is explanatory drawing which shows the shape of the probe needle concerning Embodiment 1 of this invention. It is a block diagram which shows the principal part of the vertical probe card by Embodiment 2 of this invention. It is explanatory drawing which shows the probe needle concerning Embodiment 3 of this invention. It is explanatory drawing which shows the manufacturing method of the probe needle concerning Embodiment 3 of this invention. It is a block diagram which shows the principal part of the vertical probe card by Embodiment 4 of this invention. It is sectional drawing which shows the structure of the guide hole in the guide plate concerning Embodiment 5 of this invention. It is a block diagram which shows the principal part of the conventional vertical probe card.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Probe needle | hook, 1a Tip part, 1b Root side part, 1c Center part, 1d "Constriction" part, 2 Substrate, 3, 4 Guide plate, 4a Guide hole, 5 Lubrication film, 100 Semiconductor, 100a Bonding pad.

Claims (3)

A wafer test probe for testing the operation of the semiconductor wafer by pressing the tip portion of a probe needle mounted substantially perpendicular to the substrate against the electrode pad of the semiconductor wafer and electrically contacting the tip portion with the pad. In the card
The probe needle holds the root side portion and the tip portion of the probe needle by the guide plate, and at least the root side portion and the tip end compared to the diameter of the tip portion held by the guide plate. The tip of the probe needle is formed into a substantially spherical shape having a radius of curvature of 7 to 30 microns, and the electrode pad is brought into contact with the electrode pad by the pressing. Generate shear,
The guide hole of the guide plate that holds the tip portion of the probe needle has a diameter that changes in a taper shape with respect to the length direction, and the minimum diameter is substantially the same as the diameter of the tip portion of the probe needle. A wafer test probe card characterized by the above. The guide hole of the guide plate that holds the tip of the probe needle is configured such that the diameter of the hole near the center with respect to the length direction of the guide hole is smaller than the diameters at both ends of the hole. 2. The probe card for wafer testing according to claim 1, wherein the diameter of said probe needle is substantially the same as the diameter of the tip portion of said probe needle. 3. The wafer test probe card according to claim 1, wherein a lubricating film is applied to the surface of the guide hole of the guide plate for holding the tip portion of the probe needle.

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