KR100806383B1 - Method for producing probe card - Google Patents

Abstract

A method for fabricating a probe card is provided to easily accomplish bonding force of a probe and a substrate by using a melted connection material in bonding the probe and the substrate in a junction region while preventing the melted connection material from being exhausted to the outside. A non-junction region and a junction region are defined in a manner that the junction region is positioned in an intermediate part of the non-junction region on a plurality of upper surface terminals of a substrate respectively connected to inner interconnections(406). An oxide layer is formed on in the non-junction region on the upper surface terminal. A connection material(416) is coated with respect to the junction region on the plurality of upper surface terminals. Junction parts of a plurality of probes(222) are arranged to correspond to the connection material coated in the junction region on the plurality of upper surface terminals. The plurality of probes are bonded to the plurality of upper surface terminals by the connection material. The process for forming the oxide layer in the non-junction region can include the following steps. A conductive thin film is formed in the non-junction region on the upper surface terminal. The conductive thin film is oxidized to form the oxide layer.

Description

Method for producing probe card

1 is a partial cross-sectional view schematically showing the configuration of a conventional probe card.

2 and 3 schematically show a method of manufacturing a conventional probe card.

4 shows a method of forming a substrate in a method of manufacturing a probe card according to an embodiment of the present invention.

5 shows a method of forming a probe in a method of manufacturing a probe card according to an embodiment of the present invention.

6 shows a method of manufacturing a probe card according to an embodiment of the present invention by coupling the probe of FIG. 5 to the substrate of FIG. 4.

The present invention relates to a method of manufacturing a probe card, specifically a method of manufacturing a probe card to have a sufficient adhesion between a probe of a fine pitch and a substrate.

The probe card is mounted to a probing inspection apparatus and used to electrically test each individual semiconductor element formed on the wafer.

In this case, the probe provided in the probe card contacts the metal pad, which is a contact portion of each individual semiconductor element formed on the wafer, so that the test can be performed. To this end, the pitch of the tip portion of the probe in contact with the metal pad of the semiconductor device is generally classified into a general pitch of 100 μm or more and a fine pitch of less than 100 μm, and has recently been used up to 70 μm or less.

Recently, as a method of forming a probe card, a method of forming a plurality of probes at once on a space transformer, which is a type of substrate in contact with a printed circuit board, has been attempted by using a MEMS process similar to a semiconductor etching technique. It is becoming. In the method of forming a probe card by the MEMS process, a plurality of probes are simultaneously formed by repeating a photoresist process, an etching process, a metal deposition process, and a fine grinding process, thereby making the horizontal and vertical positions and heights of the plurality of probes uniform. There are advantages to it. Therefore, when the probe card by the MEMS process is used, the plurality of probes formed on the probe card can be simultaneously brought into contact with the plurality of semiconductor elements formed on the wafer simultaneously.

In the conventional method of manufacturing a probe card by the MEMS process, as illustrated in FIGS. 1 to 3, the bump 20 is disposed on an upper portion of the terminal 11 connected to a wire for transmitting an electrical signal in the space transformer 10. After forming to a certain height, it is made by attaching the probe body 30 formed to have a probe tip 40 to the bump 20 through the junction 50.

Specifically, as shown in FIG. 2, after the photoresist layer 21 is stacked on the space transformer 10, a portion of the photoresist layer 21 corresponding to the bump is removed using a mask, and the removed portion is removed. After forming the bump 20 by plating metal on the part, the upper end of the bump 20 was plated with gold having excellent conductivity to form the junction 50.

3, a die for the probe tip 40 is formed by etching the sacrificial substrate 41, a photoresist layer 31 is laminated on the sacrificial substrate 41, and then a mask is used. By removing the portion corresponding to the probe body 30 to form a mold for the probe body 30, and then by plating a metal on the metal mold for the probe tip 40 and the probe body 30, the probe tip ( 40 and the probe body 30 are formed.

Then, the probe body 30 formed in FIG. 3 is bonded to the junction 50 of FIG. 1, and the photoresist layers are etched away to form a probe card as shown in FIG. 1. At this time, after the connection material is coated on the bump 20 to bond the body 30 and the bump 20 of the probe, the connection material is melted to bond the probe body 30 to the bump 20.

As described above, in the conventional method of manufacturing a probe card, a plurality of bumps 20 having a constant height must be formed on the space transformer 10 for bonding to the plurality of probes. However, the shapes of the plurality of terminals 11 on the commercially available space transformer 10 may be different due to various reasons in the manufacturing process, so that the plurality of bumps 20 on the space transformer 10 may be metal plated. When forming at the same time, there is a problem that the height of each bump 20 is not significantly uniform. This problem may be even greater when the bump 10 must be formed in multiple stages on the space transformer 10.

In order to solve this problem, in order to make the height of the plurality of terminals 11 on the space transformer 10 uniform, a process of polishing the terminals 11 by chemical mechanical polishing (CMP) or the like may be performed. Polishing stresses the terminal 10 of the space transformer 10, and may cause fine cracks or the like on the terminal 10 or the like. The breakage of the terminal 10 caused in this way may cause the terminal 11 to be separated from the space transformer 10 when the bump 10 is formed in the future, thereby causing an electrical opening.

On the other hand, according to the conventional method of manufacturing a probe card, the connection material is applied to the upper part of the bump 20 protruding from the substrate 10, when the connection material is melted, the molten connection material is relatively narrow upper part of the bump 20 It may flow down at the surface, such that the amount of molten interconnect material on top of bump 20 may not be sufficient. As a result, the bonding force between the desired probe body 30 and the bump 20 may not be achieved.

In particular, when the pitch of the metal pad, which is the contact portion of the semiconductor element formed on the wafer to be tested using the probe card, is minute, the pitch of the probe must be minutely corresponding to the pitch of the bump on the substrate supporting the probe. It must be fine. As a result, the amount of the connecting material that can be applied to the bump upper surface is also reduced, which limits the bonding between the probe and the bump.

In addition, when the fine pitch of the probe needs to be achieved, the height of the bump 20 should be sufficiently high. For this purpose, the bump 20 should be formed in multiple stages, and a photoresist process is involved for this purpose. However, since the shape of the space transformer is different from that of the wafer, there is a limit to the photoresist process applicable to the space transformer.

In addition, when the bump 20 is formed in multiple stages as described above, since the final bump top is smaller in size than the bump top beneath it, the amount of connection material that can be applied to the top of the final bump is limited, and accordingly, the probe body 30 And the bonding force of the bump 20 may not be sufficient.

On the other hand, in the case where the probe is directly in contact with the terminal of the substrate without bumps, in order to improve the bonding force between the probe and the terminal of the substrate, a method of stacking the connection material on the terminal of the substrate is attempted. However, in such a method, the accumulated connection material may be collapsed by the contact pressure of the probe with the contact portion of the semiconductor element. If the connection material is collapsed in this way, the probe may be in contact with an adjacent probe, thereby causing electrical failure. Can cause a short.

In order to solve the above technical problem, the present invention is to provide a probe card manufacturing method for manufacturing a probe card of a novel structure that has a sufficient bonding force between the probe and the substrate of fine pitch.

In order to solve the above technical problem, a method of manufacturing a probe card according to an aspect of the present invention is such that a junction region is positioned at an intermediate portion of an unbonded region on a plurality of upper surface terminals of a substrate, each of which is connected to an internal wiring. Setting the non-bonded region and the bonded region; Forming an oxide film on an unbonded region above the upper terminal; Applying a connection material around a junction region of the plurality of top terminal terminals; Arranging junctions of a plurality of probes to correspond to connection materials applied to junction regions above the plurality of top terminals, respectively; And bonding the plurality of probes and the plurality of top terminals to each other through the connection material.

Forming an oxide film in the non-junction region above the upper terminal

Forming a conductive thin film in an unbonded region above the upper terminal; And

And oxidizing the conductive thin film to form the oxide film.

The upper portion of the upper terminal may be formed of gold.

Etching the first sacrificial substrate to form a trench corresponding to a tip of the probe; Etching a second sacrificial substrate to form a first pillar hole corresponding to the first pillar of the probe connected to the tip; Attaching the first sacrificial substrate and the second sacrificial substrate so that the trench and the first pillar hole communicate with each other; And filling a conductive material into the trench and the first pillar hole communicated with each other. It is prepared by a probe manufacturing method comprising a.

Probe card according to another aspect of the invention a plurality of internal wiring; A plurality of terminals each connected to the plurality of internal wires, the plurality of terminals being divided into a non-bonded region and a junction region positioned at an intermediate portion of the non-bonded region; A probe body, a first pillar portion protruding from an upper surface of the probe body, a probe tip formed on an upper portion of the first pillar portion, and a bottom surface of the probe body, wherein the probe body is electrically connected to the bonding regions of the terminals. A plurality of probes integrally formed with a second pillar protruding from the plurality of probes; And a connecting portion for joining the plurality of terminals and second pillars of the plurality of probes. It includes.

The area of the junction region of the terminal corresponds to the cross-sectional area of the second pillar portion of the probe.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

Hereinafter, a method of manufacturing a probe card according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 4 to 6.

First, referring to FIG. 4, a method of manufacturing a substrate for electrically connecting a probe to a probing inspection apparatus will be described in detail.

As shown in FIG. 4A, a wiring 406 is formed therein, an upper surface terminal 402 connected to the wiring 406 at an upper end thereof, and a lower surface terminal 404 connected to a wiring 406 at a lower end thereof. ) To prepare a substrate 400 is formed. The substrate 400 includes a plurality of wiring units 406, upper terminal 402, and lower terminal 404, respectively.

The substrate 400 is not particularly limited as long as the wiring unit 406 and the upper terminal 402 and the lower terminal 404 respectively connected to both ends of the wiring unit 406 are formed therein. A space transformer made of ceramic material and commercially available may be used.

The shape of the upper terminal 402 of the substrate 400 is not limited, but as can be seen in FIG. 4B, the end of the wiring unit 406 is located at the center thereof, and the shape of the upper terminal 402 is a circular region, and the circular region. It is preferably used that is formed in the shape of a keyhole consisting of a rod region extending sufficiently long from the top. As such, the length of the rod region in the embodiment of the present invention is such that a sufficient amount of connection material corresponds to the length to which a sufficient amount of the connection material can be applied to achieve a strong bonding force between the probe and the top terminal 402 of the substrate 400. It is preferable to be set. At this time, the width of the bar area corresponds to the pitch of the probe to be bonded.

The upper and lower surfaces of the terminal 402 and the lower terminal 404 are made of a highly conductive metal, preferably gold. In the present embodiment, the shape of the upper terminal 402 is shown as a keyhole shape, but is not limited to such a shape, and is divided into a junction region bonded to the probe and a non-junction region not bonded to the probe. There is no particular limitation as long as it is located in the middle of the non-bonded region extending to a sufficient length. In this embodiment, the middle portion of the rod region corresponds to the junction region, and both distal ends and the circular region of the rod region correspond to the non-bonded region, respectively.

Thereafter, a conductive metal is added to the upper surface of the prepared substrate 400 by a sputtering method to form a conductive thin film 408 as shown in FIG. 4C. Copper is preferably used as the conductive metal, and the conductive thin film 408 has a thickness of preferably 5000 kPa.

Next, a first photoresist layer 410 is formed on the bottom surface of the substrate 400 as shown in FIG. 4D. The first photoresist layer 410 protects the lower terminal 404 in a later process.

Next, after stacking the photoresist layer on the upper surface of the conductive thin film 408 of the substrate 400, the upper surface terminal 402 by etching to remove the photoresist layer to exclude the non-bonded region that is not bonded to the probe The second photoresist layer 412 is formed on the non-bonded region 402. In FIG. 4E, the non-bonded region includes both circular and distal ends of the rod region divided by the junction region to be joined to the probe.

Thereafter, as shown in FIG. 4F, the conductive thin film 408 including the junction region is etched away using the second photoresist layer 412 as a mask.

Thereafter, as shown in FIG. 4G, the first photoresist layer 410 and the second photoresist layer 412 are removed, and only the upper portion of the non-bonded region of the upper terminal 402, that is, the circular region and the rod region, is conductive. The thin film 408 remains. At this time, the conductive thin film 408 formed on the upper terminal 402 is as shown in Figure 4h.

Thereafter, the conductive thin film 408 existing above the circular region of the upper terminal 402 is oxidized to form an oxide film 414 as shown in FIG. 4I. There is no restriction | limiting in particular as such an oxidation method, A dry heat treatment method or a wet heat treatment method is used preferably. Under the oxidation conditions of the oxidation method, the conductive thin film 408 existing above the non-joined region of the upper terminal 402 is oxidized, but the junction region of the upper terminal 402 is formed of gold having strong oxidation resistance and is not oxidized. The oxide film 414 is not formed. At this time, the oxide film 414 formed on the upper terminal 402 becomes as shown in FIG. 4J.

Thereafter, the connection material 416 is applied low on the bar region of the upper terminal 402. The application of the connecting material 416 is also applied over the non-bonded area around the junction area included in the rod area. As such a connection material, a solder paste or preform which is excellent in conductivity, bonding property and chemical resistance and melts when a temperature above the melting point is applied is preferably used. At this time, the connection material applied on the bonding region of the upper terminal 402 is not moved to the circular region of the upper terminal 402 due to the oxide film 414, and the bonding material is formed on the bonding region on the upper rod region of the upper terminal 402. Can be maintained as applied. Thus, the connecting material 416 applied on the rod region of the top terminal 402 becomes as shown in FIG. 4L.

Hereinafter, a method of manufacturing a probe connected to the substrate of FIG. 4 will be described in detail with reference to FIG. 5.

First, the silicon substrate is prepared as the first sacrificial substrate 100, and the lower portion of the first sacrificial substrate 100 is etched to form an alignment key 106 as shown in FIG. 5A.

Next, after the oxide protective film 108 is formed on the first sacrificial substrate 100, the portion corresponding to the probe tip is etched away from the oxide protective film 108, and then the oxide protective film 108 is used as a mask. The first sacrificial substrate 100 is etched to form trenches 116 for probe tips as shown in FIG. 5A.

Meanwhile, the second sacrificial substrate 200 is prepared to have a predetermined thickness. After forming a photoresist layer on the upper surface of the second sacrificial substrate 200 prepared as described above, the photoresist layer is removed from the photoresist layer corresponding to the first pillar of the probe body connected to the tip of the probe. The second sacrificial substrate 200 is etched using the mask to form a first pillar hole 204 penetrating the second sacrificial substrate 200 as shown in FIG. 5B.

Next, the second sacrificial substrate 200 formed as described above is positioned above the first sacrificial substrate 100 formed in FIG. 5A, so that the first pillar hole 204 of the second sacrificial substrate 200 is the first sacrificial substrate ( Attached to communicate with the probe tip trench 116 of 100 to form an assembly of the first sacrificial substrate 100 and the second sacrificial substrate 200. In this case, the fusion bonding method of the wafer bonder may be used to attach the first and second sacrificial substrates 100 and 200.

Next, the conductive thin film 206 is formed on the assembly of the first sacrificial substrate 100 and the second sacrificial substrate 200 using a chemical vapor deposition method, a sputtering method, or the like as shown in FIG. 5C. The conductive thin film 206 is formed on the front surface of the second sacrificial substrate 200, the side surface of the first pillar hole 204, and the side surface and the bottom surface of the probe tip trench 116. The conductive thin film 206 is preferably formed of a double layer of titanium / copper, wherein the thickness of the titanium / copper is preferably 500Å / 5000Å, respectively.

Next, after forming the photoresist layer 208 on the upper surface of the conductive thin film 206, by using a mask in the photoresist layer, the shape corresponding to the probe body connected to the first pillar of the probe is etched away, and After the photoresist layer 208 is used as a mold for the probe body, the conductive material such as metal is filled or embedded, and the photoresist layers 212 and 216 are formed and the metal filling and embedding process is repeatedly performed. A probe having a second pillar portion 214 of the probe connected to the same probe body is formed. Here, the conductive material preferably used is a metal having excellent elasticity and conductivity, and a nickel alloy such as Ni-Co or Ni-Fe is preferably used. In addition, as the metal filling and embedding process, a metal electrolytic plating method is preferably used.

Next, the photoresist layer 216 is removed by dry etching by a predetermined thickness, and the metal having excellent conductivity and bonding property is electroplated on the second pillar portion 214 of the probe exposed by the dry etching as shown in FIG. 5E. To form a junction 220 of the probe. At this time, gold is preferably used as the metal having excellent conductivity and bonding properties.

Thereafter, the photoresist layers 208, 212, and 216, the conductive thin film 206, and the like are selectively etched away to remove the first sacrificial substrate 100 and the second sacrificial substrate 200, as shown in FIG. 5F. It provides a probe 222 formed on.

Hereinafter, a method of manufacturing a probe card according to an exemplary embodiment of the present invention by combining the probe of FIG. 5 with the substrate of FIG. 4 will be described in detail with reference to FIG. 6.

Connection material coated on the bonding region of the upper terminal 402 formed on the substrate 400 with the probe 222 formed on the first sacrificial substrate 100 and the second sacrificial substrate 200. It is arranged to correspond to (416). In addition, the junction 220 of the probe 222 and the connection material 416 of the substrate 400 are contacted with each other to form a junction of the probe 222 and the substrate 400 as illustrated in FIG. 6A.

Thereafter, the connecting material 416 is heated to a melting point or more and melted to join the bonding region of the probe 222 and the upper terminal 402 of the substrate 400. At this time, the oxide film 414 on the non-bonded region of the upper terminal 402 of the substrate 400 has a low wettability with respect to the molten interconnect material 416, and thus the molten interconnect material 416 is a circular non-bonded region. Instead of flowing into the region, only the rod region of the upper terminal 402 is present around the junction region, and both are used for bonding with the junction portion 220 of the probe 222. Thereafter, the first sacrificial substrate 100 and the second sacrificial substrate 200 are selectively etched away to generate a probe 222 and a substrate 400 assembly as shown in FIG. 6B.

Thereafter, the conductive thin film 206 on the probe 222 and the oxide film 414 on the non-bonded region of the upper terminal 402 of the substrate 400 are etched away to complete a probe card as shown in FIG. 6C. .

Thus, the probe card manufactured according to the probe card manufacturing method according to an embodiment of the present invention as shown in Figure 6c, a plurality of internal wiring; A plurality of terminals each connected to the plurality of internal wires, the plurality of terminals being divided into a non-bonded region and a junction region located at an intermediate portion of the non-bonded region; A probe body, a first pillar portion protruding from an upper surface of the probe body, a probe tip formed on an upper portion of the first pillar portion, and a bottom surface of the probe body, wherein the probe body is electrically connected to the bonding regions of the terminals. A plurality of probes integrally formed with a second pillar protruding from the plurality of probes; And a connecting part for joining the plurality of terminals and second pillars of the plurality of probes. At this time, the area of the junction region of the terminal is preferably set corresponding to the cross-sectional area of the second pillar portion of the probe.

As described above, according to the method of manufacturing a probe card of the present invention, a region of an upper surface terminal of a substrate is divided into a non-bonded region not bonded to a probe and a junction region disposed at an intermediate portion of the non-bonded region, and bonded to a probe. In addition, after forming the conductive thin film for the non-bonded region, the conductive thin film is oxidized to prevent the connection material applied to the bonded region from being transferred to the non-bonded region. Accordingly, when the junction of the probe is bonded to the junction material of the junction region, and the junction material is melted, the molten junction material is not discharged to the outside as in the prior art using bumps, and the probe and the substrate are completely in the junction region. Since it is used for bonding, the bonding force of a target probe and a board | substrate can be achieved easily. Therefore, according to the probe card manufacturing method of the present invention, even when a small amount of the connecting material is used, the bonding force between the probe and the substrate having a fine pitch can be sufficiently achieved.

In addition, according to the method of manufacturing a probe card of the present invention, the width of the upper terminal of the substrate is implemented in the fine pitch so as to correspond to the probe of the fine pitch, and the non-bonded region of the upper terminal of the fine pitch except for the junction region to be bonded to the probe is provided. It was possible to secure a sufficient coating area for the connection material to be extended. In addition, by applying a sufficiently low connection material to the application area secured in this way, it is possible to prevent the collapse of the connection material supporting the probe as in the prior art, thereby preventing electrical contact between adjacent probes that may occur.

In addition, according to the method of manufacturing a probe card of the present invention, unlike the prior art of generating a bump on the substrate and bonding the bump to the probe body, it is not necessary to generate the bump, which is to be performed on the substrate for the bump generation. There is no need for a photoresist process, an etch removal process, or a polishing process. Thus, the steps of the process for the manufacture of the probe card can be reduced. In addition, the method of manufacturing the probe card of the present invention does not generate bumps, and thus, the problem that may occur due to different heights of bumps generated as in the prior art does not occur, and polishing for matching the horizontality of the upper surface terminals formed on the substrate. The process is unnecessary, thereby preventing cracking of the terminal, separation of the upper surface terminal from the substrate, and thus electrical opening, which may occur due to this polishing process. In addition, since no bumps are generated, all areas of the upper terminal of the substrate can be used as it is for bonding with the probe, so that a wider pitch can be secured than the prior art for generating bumps, thereby applying the connection material. It is possible to secure a sufficient area.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the technical idea of the present invention, and it is obvious that the present invention belongs to the appended claims. Do.

Claims (6)

Setting the non-junction region and the junction region so that the junction region is located at an intermediate portion of the non-junction region on the plurality of upper surface terminals of the substrate respectively connected to the internal wiring; Forming an oxide film on an unbonded region above the upper terminal; Applying a connection material around a junction region of the plurality of top terminal terminals; Arranging junctions of a plurality of probes to correspond to connection materials applied to junction regions above the plurality of top terminals, respectively; And Bonding the plurality of probes and the plurality of top terminals to each other through the connection material; Probe card manufacturing method comprising a. The method of claim 1, Forming an oxide film in the non-junction region above the upper terminal Forming a conductive thin film in an unbonded region above the upper terminal; And Oxidizing the conductive thin film to form the oxide film; The probe card manufacturing method comprising a. The method of claim 1, And the upper portion of the upper terminal is formed of gold. The method of claim 1, The probe is Etching the first sacrificial substrate to form a trench corresponding to the tip of the probe; Etching a second sacrificial substrate to form a first pillar hole corresponding to the first pillar of the probe connected to the tip; Attaching the first sacrificial substrate and the second sacrificial substrate so that the trench and the first pillar hole communicate with each other; And Filling a conductive material into said trench and said first pillar hole; The probe card manufacturing method characterized in that it is manufactured by a probe manufacturing method comprising a. A plurality of internal wirings; A plurality of terminals each connected to the plurality of internal wires, the plurality of terminals being divided into a non-bonded region and a junction region positioned at an intermediate portion of the non-bonded region; A probe body, a first pillar portion protruding from an upper surface of the probe body, a probe tip formed on an upper portion of the first pillar portion, and a probe body, the junction body being electrically connected to each of the junction regions of the plurality of terminals. A plurality of probes integrally formed with a second pillar protruding from the lower surface; And A connecting portion joining the plurality of terminals and second pillar portions of the plurality of probes; Probe card comprising a. The method of claim 5, And the area of the junction region of the terminal corresponds to the cross-sectional area of the second pillar of the probe.

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