WO2008123638A1

WO2008123638A1 - Needle of probe card and method of manufacturing the same

Info

Publication number: WO2008123638A1
Application number: PCT/KR2007/002942
Authority: WO
Inventors: Joon Seok Oh
Original assignee: Im Co., Ltd.
Priority date: 2007-04-04
Filing date: 2007-06-18
Publication date: 2008-10-16
Also published as: TW200841017A; KR100790465B1

Abstract

A needle of probe card and a fabrication method thereof are provided. The needle of probe card includes a post part, a beam part, a tip part and a wall part, with a monolithically formed type, for enhancing an exact and reliable characteristic test and a durability of the needle and for fabricating needles more simply. The post part has a given height, and a lower end part of the post part is combined with a terminal of a substrate. One end of the beam part is combined with one side part of an upper part of the post part, and another end thereof extended horizontally is formed with a vertical bending characteristic. The tip part is formed being protruded up from another end corresponding to the one end of the beam part, and a top portion of the tip part has a tip shape. The wall part is formed in a shape of having a constant gap from both side faces of the beam part combined with the post in a paralleled shape so as to control a side-directional motion of the beam part in a type of covering both side faces of the beam part with keeping the constant gap.

Description

NEEDLE OF PROBE CARD AND METHOD OF MANUFACTURING THE SAME

[Technical Field]

The present invention relates to a transfer efficiency of electrical signals in a semiconductor memory device. The invention relates to a needle of probe card and a fabrication method thereof, for a stable connection of needle with a connection terminal and an increase in a transfer efficiency of electrical signals.

[Background Art]

In general, semiconductor devices are fabricated through many processes, principally, such as a wafer process, fabrication(FAB) processes and assembly processes.

Wafers are fabricated through wafer processes, and a plurality of semiconductor devices are formed on the wafer through the FAB processes, and the plurality of semiconductor devices are definitely passed through an electrical die sorting(hereinafter, referred to as EDS) to sort a good quality from a bad quality of the semiconductor devices.

The EDS is executed to sort good quality and bad quality of numerous semiconductor devices formed on the wafer and also to repair semiconductor devices available to repair among defective semiconductor devices or to previously feed back for problems in the FAB processes or eliminate defective semiconductor device, thereby cutting cost down in an assembly and package test.

For the EDS there may be needed a tester and a probe system. In the probe system a probe card is adapted that is in contact with an electrode pad of a semiconductor device formed on the wafer. The probe card is used to transfer signals produced in a tester through a use of needle that is very fine, to an electrode pad of each semiconductor device of a wafer being in contact with the needle, thus it is tested whether semiconductor devices are good quality or defective.

FIG. 1 is a cross-sectional view of a probe card according to a conventional art. In upper and lower parts of a main substrate 1 having a general circular type, a reinforcement plate 2 and a fixation plate 3 are individually combined with respective corresponding faces, to prevent the substrate from being varied such as being curved, and plural needles 4 are provided with the fixation plate 3 adapted in the lower part of the substrate. Needles 4 are symmetrically arrayed in both sides of the bottom face of the fixation plate 3 of the main substrate, and respective needles 4 are fixed being isolated from one another through an isolator 5.

In other words, an upper end part of the needle 4 adheres to a wiring pattern formed on a lower face of the main substrate 1, deviating from an outer side of the fixation plate 3. The needle 4 is fixed by the isolator 5 with a slow slant angle to the fixation plate

3. A lower end part of the needle 4 is formed being bent down, thus forming a tip shape that is in contact with a pattern terminal of a tested device.

Needle 4 of the probe card generally has a wire type or blade type of a thin plate. In a recent fabrication of needles 4, it becomes a very important issue to fabricate the needles appropriately corresponding to the development of semiconductor technique.

As semiconductor devices become increasingly high integrated and high density for semiconductor patterns, micro-sized needles corresponding thereto and the configuration of high density for the needles are essentially needed.

Such tendency brings about fabricating needles in a desired thin plate shape from a silicon substrate through photo and plating processes, thus making a fabrication of needles very simple.

Furthermore, the portion except a tip portion of the needle is formed in a way of making the needle grower through the photo and plate processes in the same method as the needle fabrication, that is, of increasing a thickness thereof, thus a portion having an elasticity such as the tip part and the beam part is more reinforced so as to provide stable operation characteristic.

However, the reinforced beam part may relatively be weakened corresponding to the reinforced thickness relating to the operation characteristic, thus an elastic characteristic is reduced. On the other hand, it may be caused a serious problem that in a vertical curving variation of needle, the needle may also move in a side direction, causing a connection error, despite that a vertical elasticity is very important in order for a stable contact of the needle with a tested device.

[Disclosure of Invention]

Accordingly, some embodiments of the invention provide a needle of probe card. A beam part and a tip part have the same thickness, maximizing an operation characteristic through a curving variation. Both sides of the beam part are covered by a wall part, maintaining a minute gap therebetween. A post part is adapted so as to appropriately correspond to a distance from a terminal of a tested device. A precise and stable test can be executed.

Some embodiments of the invention provide a method of fabricating a needle of probe card. Needles can be fabricated more simply in a desired size and shape by using a thin film fabrication technique, thereby remarkably increasing a productivity of needles and furthermore appropriately corresponding to a pattern test of higher integrated and higher density.

According to some embodiments of the invention, a needle of probe card comprises a post part, a beam part, a tip part and a wall part. The post part has a given height, and a lower end part of the post part is combined with a terminal of a substrate. One end of the beam part is combined with one side part of an upper part of the post part, and another end thereof is formed with a bending characteristic. The tip part is formed being protruded up from another end corresponding to the one end of the post part, and a top portion of the tip part has a tip shape. The wall part is formed in a shape of having a constant gap from both side faces of the beam part combined with the post so as to control a side-directional motion of the beam part and the tip part, that is, in a type of covering both side faces of the beam part with keeping the constant gap.

The beam part has a cantilever shape of being extended from one side face middle portion of the upper part of post part and monolithically formed therefrom.

The wall part is formed from two portions of an upper side face of the post part, in a both-side wall type, covering the beam part from both sides thereof, maintaining a constant gap therebetween.

The wall part is provided with a connecting part to monolithically couple mutually opposite both side walls of the wall part, and is formed so as not to interfere a vertical bending characteristic of the beam part. In particular, an end part of the wall part is formed to be shorter than the beam part so that an end portion of the beam part with the tip part is exposed.

According to some embodiments of the invention, a needle of probe card comprises a post part, a beam part, a tip part and a wall part.

The post part has a given height and a lower end part of the post part is combined with a terminal of a substrate. The beam part is formed in a type of being fore-extended from both portions of an upper side face of the post part and being monolithically connected between end parts of the both extended portions in a '^c '-shape. One end of the beam part corresponding to another end thereof combined with the post part is formed to have a vertical bending characteristic.

The tip part is formed being protruded up from an end point portion formed monolithically with the beam part, and a top part of the tip part has a tip shape.

The wall part is formed being fore extended from one side face of upper part of the post part in a monolithic structure, and side faces of the extended part of the wall part are spaced with a constant gap from inner side faces of the beam part, so as to control a side directional motion of the beam part.

The beam part may have the same height as the post part.

A constant length provided from an end point portion of the beam part may be formed to be thinner than an end part thereof combined monolithically with the post part, so that the end point portion of the beam part has a vertical bending characteristic.

According to some embodiments of the invention, a method of fabricating a needle of probe card comprises forming a first conductive layer by performing a plating for a trench formed on a silicon substrate through a deep etch; creating a first gap by using a seed layer for the first conductive layer; forming a second conductive layer through a plating, with an interposition of the first conductive layer and the first gap; producing a second gap by using a seed layer for the second conductive layer; and forming a third conductive layer through a plating, with an interposition of the second conductive layer and the second gap.

The method of fabricating the needle may comprise the following processes. The surface of silicon substrate is covered with photoresist, and a photoresist pattern is formed in a desired shape through an exposure and a developing by using an aligner.

A deep etch for the silicon substrate is performed by using the photoresist pattern as a mask, resulting in forming a trench. Photoresist film remaining on the surface of the silicon substrate is eliminated, and then a first seed layer is deposited with a given thickness along the surface of the silicon substrate and an inner face of the trench.

The surface of the first seed layer is covered with photoresist, and then a photoresist pattern is formed through an exposure and a developing by using an aligner. The photoresist pattern and trench are filled with conductive material.

The silicon substrate with the conductive material is polished, forming a first conductive layer.

On the first conductive layer and its outer side surface for the silicon substrate, a second seed layer is deposited with a thin thickness. The surface of the second seed layer is covered with photoresist of thin thickness, and a photoresist pattern is formed through an exposure and a developing by using an aligner.

A portion of the second seed layer is removed by using the photoresist pattern as a mask. The surface of remaining photoresist is again covered with photoresist of a constant thickness, and photoresist pattern is formed by an exposure and a developing using an aligner and a plasma ashing process.

The photoresist pattern is filled with conductive material.

Photoresist remaining on an outer side of the substrate with the conductive material is polished, forming a second conductive layer with a constant thickness. On the second conductive layer and an outer side surface of the silicon substrate, a third seed layer is deposited with a thin thickness.

The surface of the third seed layer is covered with photoresist of thin thickness, and a photoresist pattern is formed through an exposure and a developing by using an aligner and a plasma ashing process.

A portion of the third seed layer is removed by using the photoresist pattern as a mask.

The surface of remaining photoresist is again covered with photoresist of a constant thickness, and photoresist pattern is formed by an exposure and a developing using an aligner and a plasma ashing process.

The photoresist pattern is filled with conductive material.

Photoresist remaining on an outer side of the substrate with the conductive material is polished, forming a third conductive layer with a constant thickness.

Remaining photoresist on respective layers is removed by using cleaning solution. Remaining first to third seed layers are removed by using specific chemical, separating an assembly of the first to third conductive layers from the silicon substrate, thereby fabricating the needle.

[Description of Drawings] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 is a cross-sectional view of a probe card according to a conventional art; FIG. 2 is a perspective view illustrating a configuration of needle according to an embodiment of the invention; FIG. 3 is a side view of FIG. 2;

FIG. 4 is a top plan view of needle shown in FIG. 2 according to an embodiment of the invention;

FIG. 5 is a perspective view of needle according to another embodiment of the invention;

FIG. 6 is a perspective view of needle according to another embodiment of the invention;

FIGS. 7 A to 7U illustrate steps of needle fabricating processes according to an embodiment of the invention; FIG. 8 is a plan view illustrating a formation of second conductive layer in needle fabricating processes according to an embodiment of the invention; and

FIG. 9 is a plan view illustrating a formation of first conductive layer or third conductive layer in the needle fabricating processes according to an embodiment of the invention.

[Best Mode]

Embodiments of the present invention now will be described more fully hereinafter with reference to FIGS. 2 to 9, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Exemplary embodiments of the present invention are more fully described below with reference to FIGS. 2 to 9. This invention may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein; rather, these exemplary embodiments are provided so that this disclosure is thorough and complete, and conveys the concept of the invention to those skilled in the art.

A method of fabricating a needle having a blade type of thin plate and having an operation structure of a cantilever type is described according to some embodiments of the invention.

A needle of the cantilever type generally has a characteristic that one end thereof is fixed and another end thereof has an elastic variation up and down on an axis of the fixed one end. FIG. 2 is a perspective view illustrating a configuration of needle according to an embodiment of the invention. FIG. 3 is a side view of FIG. 2 and illustrates a configuration of needle 10 formed in the blade type of thin plate.

The needle 10 of the blade type is formed as the configuration of thin plates through a thin film fabrication technique applied to semiconductor manufacturing processes.

The needle 10 of blade type is generally formed of a post part 11, a beam part 12 and a tip part. For the needle 10, a plurality of needles are arrayed, forming a needle assembly needed for one electrical test.

In the configuration of the needle 10, the post part 11 is fixed on a ceramic or silicon substrate having a given circuit pattern and a connection bump. A length or height of the post part 11 decides a length or height from a pattern terminal of a tested device.

In particular, the post part 11 is formed in a size that a contact area of a connection portion is not deviated from the bump so as to get a stable combination with the connection bump of the ceramic or silicon substrate.

In the beam part 12, one end thereof is formed monolithically with an upper end part of the post part 11, and another end thereof is formed to be elastic up and down.

That is, one end of the beam part 12 is coupled with the post part 11, and another end thereof is formed to have a vertical bending characteristic with an elastic force. FIG. 4 is a top plan view of the needle shown in FIG. 2.

In the needle 10 of the invention, the beam part 12 has a monolithic structure that one end thereof is combined with one side of an upper part of the post part 11.

The beam part 12 is formed with a thickness thinner than the post part 11 so as to be coupled with a middle portion of the thickness of one side part of the post part 11. The beam part 12 is pressed by a pressurized force, producing the bending characteristic, and a varied state is restored by itself elasticity.

In a direction the bending characteristic acts, the beam part 12 is formed to have a sufficient area to allow the bending characteristic, while, the thickness thereof combined with the post part 11 is provided thinnest as possible. The tip part 13 is formed being protruded up from an end portion thereof corresponding to one end part of the beam part 12 connected to the post part 11, so that the tip part is in contact with a terminal of a tested device.

The tip part 13 may have a tip shape for a point thereof since the tip shape is most advantageous to a signal transfer efficiency. The wall part 14 is formed being extended from two portions of one side face of the post part 11 in a shape that both sides of the beam part 12 have a gap from the wall part so that the beam part 12 is covered maintaining the gap from a side direction. Thus, the wall part 14 of both sides may be thicker or thinner than the beam part 12, but for an outer surface of the wall part 14, it may be most beneficial to make the outer surface have the same flat level as an outer surface of the post part 11.

On the other hand, the wall part 14 is provided as a side-directional motion prevention part so as not to generate an excessive motion in a side direction when the beam part 12 appears a vertical bending characteristic, thus it may be more beneficial to all cover side parts of a section in which the beam part 12 moves vertically, and for that, the wall part 14 may have the same height as the post part 11 as shown in FIG. 5.

Especially the wall part 14 of both sides may be most beneficial to have a connection part 15 to monolithically connect between the both-side walls so as not to be interfered by operation of the beam part 12 with the vertical elasticity characteristic, as shown in FIGS. 3 and 4. Further, according to an embodiment of the invention, a contrary operating portion to the embodiment of FIG. 5, may be formed as shown in FIG. 6.

In other words, though it is the same as the above-mentioned embodiment in the invention that a lower end part of the post part 11 is combined with a terminal of the substrate, with a given height of the post part 11 ; in this embodiment, both end parts are formed being fore-extended from two portions of one side upper face of the post part 11, and the both end parts are connected with each other monolithically in a ' ^"^ '-shape.

Thus, the beam part 12 is formed so that one end thereof corresponding to another end combined with the post part 11 can have a vertical bending characteristic.

And an upper face portion of the one end of the beam part 12 is protruded up, forming the tip part 13, and an upper part of the tip part 13 may beneficially have a shape of tip.

Meanwhile, in the wall part 14 according to the embodiment of the invention, one end thereof is combined monolithically with one side face of the post part 11 like the beam part 12, and the one end is extended fore from the post part, and an outer side face of the extended portion is spaced with a constant gap from an inner side face of the beam part

12, so that a side-directional motion of the beam part 12 is controlled by the wall part.

Fabrication processes of a needle with such configuration are described in detail, as follows.

In a fabrication of the needle according to an embodiment of the invention, plating is performed in a trench formed on a silicon substrate through a deep etch, and a first conductive layer is formed thereon. On the first conductive layer, a first gap is formed by using a seed layer, and then a second conductive layer is formed through a plating with an interposition of the first conductive layer and the first gap therebetween. Then, on the second conductive layer, a second gap is formed by again using the seed layer. With an interposition of the second conductive layer and the second gap therebetween, a third conductive layer is formed through a plating, thereby fabricating the needle that is formed of a plurality of conductive layers with constant gaps.

It may be beneficial herein to monolithically couple the first, second and third conductive layers, that is, so that one ends thereof are connected monolithically with one another, and it may be most beneficial to monolithically connect between respective one sides of the first and second gaps.

Describing more in detail, FIG. 7 illustrates fabrication procedures of a needles according to an embodiment of the invention.

As shown in FIG. 7, needle 10 is fabricated with a silicon substrate Si got through a thin film fabrication technique. That is, a surface of the silicon substrate Si is first covered with photoresist PRl, and a photoresist pattern Pl shown in FIG. 7B is formed through exposure and developing using an aligner(not shown).

An etching is performed for the photoresist pattern Pl of the silicon substrate Si by using remaining photoresist PRl , thus forming a trench pattern T shown in FIG. 7C.

Photoresist remaining on the silicon substrate Si is eliminated, and then a first seed layer SLl of a thin layer to increase a deposition efficiency of conductive material is covered along a surface of the silicon substrate Si on which the trench pattern was formed.

The seed layer SL may be formed of one material such as Cu, but it may be most beneficial to form the seed layer SL by depositing Cu or Al, Au as a seed layer on an adhesion layer such as Ti or Cr.

Photoresist PR2 is again covered with the surface of the seed layer SL, and then a photoresist pattern P2 coupled with the trench pattern is formed through exposure and developing using an aligner as shown in FIG. 7E. The trench pattern and photoresist pattern P2 are filled with conductive material

Ml through a plating as shown in FIG. 7F.

When in the state of filling the conductive material Ml therein, the surface is polished so as to together eliminate the first seed layer SLl formed on an outer side of the pattern; a first conductive layer MLl is formed on the silicon substrate Si as shown in FIG. 7G.

The polished surface is covered with a second seed layer SL2 as shown in FIG.

7H, and photoresist PR3 is again covered thereon and then a portion of the photoresist

PR3 is removed as shown in FIG. 71 through exposure and developing using an aligner, thereby forming a photoresist pattern P3. By using the patterned photoresist pattern P3 as a mask, a portion of the second seed layer SL2 opened through the photoresist pattern P3 is removed through use of BOE solution and specific chemical, thereby producing a shape shown in FIG. 7J.

In the formation of the second seed layer SL2, Ti as an adhesion layer may beneficially be eliminated by BOE solution, and Cu as the seed layer may beneficially be removed by specific chemical.

After patterning the second seed layer SL2, the surface of photoresist PR3 and patterned second seed layer SL2 is covered with photoresist PR4, and thus a pattern structure shown in FIG. 7K is formed through exposure, developing and a plasma ashing process. The photoresist PR4 is patterned through exposure and developing by using an aligner, thus forming a photoresist pattern P4. The photoresist PR3 is exposed on the bottom thereof through the photoresist pattern P4. This exposed photoresist PR3 is eliminated through plasma ashing process so as to be patterned in the same shape as the photoresist pattern P4. That is, as the bottom of the photoresist pattern P4, the second seed layer SL2 and the pattern thereof are shown together, and conductive material M2 is filled therein through a plating as shown in FIG. 7L.

When the conductive material M2 is filled, the photoresist pattern P4 remaining together with conductive material M2 is polished for the surface thereof, corresponding to a given thickness, thereby forming a second conductive layer ML2.

On the polished surface, a third seed layer SL3 is again covered as shown in FIG. 7M.

The third seed layer SL3 is covered with photoresist PR5 as shown in FIG. 7N, and a photoresist pattern P5 is formed through exposure and developing using an aligner by using the method like in FIGS. 71 and 7J. Then, third seed layer SL3 is patterned as shown in FIG. 70 by using the photoresist pattern P5 as a screen.

The surface of photoresist PR5 on which the photoresist pattern P5 is formed, is again covered with photoresist PR6, and a photoresist pattern P6 is formed as shown in FIG. 7P through exposure and developing using an aligner and a plasma ashing process. The photoresist pattern P6 is formed with the same length and shape as the first conductive layer MLl.

Since immediately after the formation of photoresist pattern P6, there is exposed a portion of the photoresist PR5 under the photoresist pattern P6, this exposed portion is eliminated through the plasma ashing process as shown in FIG. 7Q. The photoresist pattern P6 is filled with conductive material M2 through a plating as shown in FIG. 7R, and the surface of remaining photoresist PR6 and conductive material M2 is polished, corresponding to a given thickness, thus forming a third conductive layer ML3 as shown in FIG. 7S.

The third conductive layer ML3 may be most beneficial to have the same thickness as the first conductive layer ML 1.

When including the formation of the third conductive layer ML3, all configuration for the needle according to an embodiment of the invention is completed; still remaining photoresist PR3-PR6 is perfectly removed by using cleaning solution, thereby resulting in like FIG. 7T. By again using BOE solution or specific chemical based on material of the seed layer together with the BOE solution in the state that photoresist PR3-PR6 is removed, the first to third seed layers SL1-SL3 are eliminated from the first to third conductive layers ML1-ML3 that are combined monolithically with one another, and at this time, the silicon substrate Si is also removed, thereby obtaining the needle 10 shown in FIG. 7U. The first conductive layer MLl and the third conductive layer ML3 of the needle 10 obtained through such steps become post part 11 and wall part 14 of the needle 10, and the second conductive layer ML2 becomes the post part 11, beam part 12 and tip part 13.

In particular, an end part of the second conductive layer ML2, whose length is longer than the first and second conductive layers MLl and ML3, is protruded up, thus forming the tip part 13. One end part that connects between the first to third conductive layers ML1-ML3, becomes the post part 11.

On the other hand, in fabricating the needle 10, as shown in FIG. 8 the second conductive layer ML2 provides the configuration that one end of the beam part 12 is formed from one end portion of the post part 11, being coupled in a direction of right angle with the post part 11, and that a thickness of the beam part 12 is getting more thinned from one end part coupled with the post part 11 toward another end part, and an end point of the beam part 12 is protruded in a direction corresponding to a length direction of the post part 11, thus forming the tip part 13.

In the first conductive layer MLl and the third conductive layer ML3 constituting the post part 11 and the wall part 14, an area of a part as the post part 11 is the same as the second conductive layer ML2, while, a part as the wall part 14 may be more beneficial to be formed larger than an area of the beam part 12 of the second conductive layer ML2, as shown in FIG. 9.

In particular, in mutually opposite faces of the first conductive layer MLl and the third conductive layer ML3, portions that does not overlap with the end point part of the beam part 12 of the second conductive layer ML2 are monolithically connected to each other, thereby forming a connection part 15, so that both wall parts 14 of the first and third conductive layers MLl and ML3 can be kept stable.

As described above, according to some embodiments of the invention, the beam part 12 and the tip part 13 of the needle 10 are formed thinnest as possible through use of a thin film fabrication technique, and furthermore the beam part 12 is formed to have a sufficient height in a direction a bending characteristic is provided.

At this time, for example, when an entire thickness of the needle 10, thickness of the post part 11, is 80μm, the wall part 14 of both sides formed of the first conductive layer MLl and the third conductive layer ML3 is formed with a thickness of 28μm, and among first to third seed layers SL1-SL2, at least second seed layer SL2 and third seed layer SL3 are formed with a thickness of 2μm. Also, the beam part 12 and the tip part 13 formed of the second conductive layer ML2 may be most beneficial to be formed with a thickness of 20μm so as to be thinner as compared with the post part 11. Such thickness described above is just a beneficial example, thus other thickness is available.

In addition, a distance control based on a distance from a terminal of a tested device can be simply performed by a height control of the post part 11 through a patterning, whereby providing a stable test. When the thickness of the beam part 12 and the tip part 13 for the needle 10 is thinned at maximum, a bending characteristic efficiency of the needle 10 is satisfactory, meanwhile a motion thereof in a side direction may be severe. But, in the invention, both sides of the beam part 12 and the tip part 13 of the needle are covered with a gap by the wall part 14, thereby preventing the beam part 12 and the tip part 13 from any direct influence outside and additionally preventing the beam part 12 and the tip part 13 from being varied, resulting in a constant connection efficiency with a tested device.

Especially, in the fabrication of the needle 10, an end point part of the beam part 12, adapted as the tip part 13, is protruded higher than an end part of the wall part 14, and the needles 10 are arrayed being faced to one another so that the tip parts 13 of the needles arrayed mutually facing become alternate to one another, accordingly a connection with high integrated and high density terminal can be stable.

As described above, according to some embodiments of the invention, needles can be simply fabricated in desired size and shape through a thin film fabrication technique, and particularly, a connection efficiency of needle with a terminal of tested device can be enhanced.

In particular, a beam part and a tip part having a bending characteristic of needle are formed thinnest as possible, maximizing an operation characteristic, and simultaneously, a wall part is formed being spaced with a fine gap from both sides of the beam part, thus preventing a side-directional motion of the beam part and the tip part. A precise and stable connection of the needle with a terminal of tested device can be provided, preventing the beam part and the tip part from any external collision or interference.

That is, even if the beam part and the tip part do not have to increase the thickness in order to prevent their side-directional motion, an operation characteristic thereof can become considerably increased with the thinnest thickness, and in addition, a side- direction motion of the beam part can be prevented by the wall part, substantially reducing an influence from the outside. Accordingly, an exact and stable test can be obtained.

It will be apparent to those skilled in the art that modifications and variations can be made in the present invention without deviating from the spirit or scope of the invention. Thus, it is intended that the present invention cover any such modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Accordingly, these and other changes and modifications are seen to be within the true spirit and scope of the invention as defined by the appended claims.

In the drawings and specification, there have been disclosed typical embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.

Claims

WHAT IS CLAIMED IS:

1. A needle of probe card, comprising: a post part having a given height, a lower end part of the post part being combined with a terminal of a substrate; a beam part, whose one end is combined with one side part of an upper part of the post part, and whose another end horizontally extended therefrom is formed to have a vertical bending characteristic; a tip part formed being protruded up from another end corresponding to the one end of the beam part combined with the post part, a top portion of the tip part having a tip shape; and a wall part formed in a shape of having a constant gap from both side faces of the beam part combined with the post part and so having a paralleled type, the wall part being for controlling a side-directional motion of the beam part and the tip part in a type of covering both side faces of the beam part with keeping the constant gap, the post part, the beam part, the tip part and the wall part being monolithically combined with one another.

2. The needle of claim 1, wherein the beam part has a cantilever shape of being extended from one side face middle portion of the upper part of post part and monolithically formed therefrom.

3. The needle of claim 1, wherein the wall part is formed from two portions of an upper side face of the post part, in a both-side wall type, covering the beam part from both sides thereof, maintaining a constant gap therebetween.

4. The needle of claim 1, wherein the wall part is provided with a connecting part to monolithically couple mutually opposite both side walls of the wall part, and is formed so as not to interfere a vertical bending characteristic of the beam part.

5. The needle of claim 1, wherein an end part of the wall part is formed to be shorter than the beam part so that an end portion of the beam part with the tip part is exposed.

6. A needle of probe card, comprising: a post part having a given height, a lower end part of the post part being combined with a terminal of a substrate; a beam part formed in a type of being fore-extended from both portions of an upper side face of the post part and being monolithically connected between end parts of the both extended portions in a '^: '-shape, one end of the beam part corresponding to another end thereof combined with the post part being formed to have a vertical bending characteristic; a tip part formed being protruded up from an end point portion formed monolithically with the beam part, and a top part of the tip part has a tip shape; and a wall part formed being fore extended from one side face of upper part of the post part in a monolithic structure, and side faces of the extended part of the wall part being spaced with a constant gap from inner side faces of the beam part, so as to control a side directional motion of the beam part, the post part, beam part, the tip part and the wall part being monolithically combined with one another.

7. The needle of claim 6, wherein the beam part has the same height as the post part.

8. The needle of claim 6, wherein a constant length provided from an end point portion of the beam part is formed to be thinner than an end part thereof combined monolithically with the post part, so that the end point portion of the beam part has a vertical bending characteristic.

9. A method of fabricating a needle of probe card, comprising: forming a first conductive layer by performing a plating for a trench formed on a silicon substrate through a deep etch; creating a first gap by using a seed layer for the first conductive layer; forming a second conductive layer through a plating, with an interposition of the first conductive layer and the first gap therebetween; producing a second gap by using a seed layer for the second conductive layer; and forming a third conductive layer through a plating, with an interposition of the second conductive layer and the second gap therebetween.

10. The method of claim 9, wherein the first, second and third conductive layers are monolithically connected with one another in one side of the first and second gaps.

11. The method of claim 9, wherein the seed layer is formed of laminated Ti and Cu.

12. A method of fabricating a needle of probe card, comprising: covering a surface of silicon substrate with photoresist, and forming a photoresist pattern in a desired shape through an exposure and a developing by using an aligner; forming a trench by performing a deep etch for the silicon substrate by using the photoresist pattern as a mask; eliminating photoresist remaining on the surface of the silicon substrate, and then depositing a first seed layer with a thin thickness along the surface of the silicon substrate and an inner face of the trench; covering the surface of the first seed layer with photoresist with a thin thickness, and then forming a photoresist pattern(P2) through an exposure and a developing by using an aligner; filling the photoresist pattern(P2) and the trench with conductive material, polishing a surface of the silicon substrate with the conductive material, and then forming a first conductive layer; depositing a second seed layer with a thin thickness on the first conductive layer and its outer side surface for the silicon substrate; covering the surface of the second seed layer with photoresist of thin thickness, and forming a photoresist pattern through an exposure and a developing by using an aligner; removing a portion of the second seed layer by using the photoresist pattern as a mask; again covering the surface of remaining photoresist with photoresist of a constant thickness, and forming a photoresist pattern(P4) through an exposure and a developing using an aligner and a plasma ashing process; filling the photoresist pattern(P4) with conductive material, and polishing photoresist remaining on an outer side of the substrate with the conductive material, and thus forming a second conductive layer with a constant thickness; depositing a third seed layer with a thin thickness on the second conductive layer and its outer side surface for the silicon substrate; covering the surface of the third seed layer with photoresist of a thin thickness, and forming a photoresist pattern through an exposure and a developing by using an aligner; removing a portion of the third seed layer by using the photoresist pattern as a mask; again covering the surface of remaining photoresist with photoresist of a constant thickness, and forming a photoresist pattern(P6) through an exposure and a developing using an aligner and a plasma ashing process; filling the photoresist pattern(P6) with conductive material, and polishing photoresist remaining on an outer side of the substrate with the conductive material and thus forming a third conductive layer with a constant thickness; eliminating remaining photoresist on respective layers by using cleaning solution; and removing remaining first to third seed layers by using specific chemical, and separating an assembly of the first to third conductive layers from the silicon substrate.

13. The method of claim 12, wherein the first to third seed layers each are formed ofTi and Cu.