KR100555585B1 - Probe card having micro-spring and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a probe card having a micro spring and a method of manufacturing the same, and to a probe card for compensating elastic force and minimizing damage to a contact pad while maintaining an OD (over drive) of a probe by the micro spring. It is about.

In order to achieve this, the present invention provides a probe card comprising: a probe substrate on which a circuit pattern is implemented; A plurality of probes each having a bump formed on the probe substrate and a support beam having one end supported by the bump and a tip formed at a free end of the support beam; Disclosed is a probe card, comprising: a plurality of micro springs positioned on a vertically downward direction of the probe tip and formed on a probe substrate.

Semiconductor inspection, probe card, over drive (OD), micro spring

Description

Probe card having micro-spring and manufacturing method

1A and 1B are views for explaining the structure and function of a conventional cantilever probe card,

2 is a front view showing one embodiment of a probe card according to the present invention;

3a and 3b are a front view and a plan view showing a micro spring as one component of FIG.

4 is a view for explaining an operating state of the probe card of FIG.

Figures 5a to 5h is a side cross-sectional view for explaining an embodiment of a probe card manufacturing method according to the present invention,

6A to 6C are side cross-sectional views for explaining another embodiment of the method of manufacturing a probe card according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: cantilever probe card 110,310: probe substrate

111,311: Connection terminal 120,320: Probe

121,321: bumps 122,322,601,701: support beam

123,323,602,702: tip portion 200,400: semiconductor element

201,401: pad 300: probe card

330: micro spring 332: copper film

333: chromium film 334: palladium alloy film

500: probe substrate 501: silicon nitride film

502: silicon oxide film 503: copper film

504: chrome film 505: photoresist pattern

505a: bump 506: elastic curing agent

600: sacrificial substrate

700: silicon wafer for probe bonding

703: space portion 800: laser light source portion

801: laser

The present invention relates to a probe card having a micro spring and a method of manufacturing the same, and more particularly, to a probe card further comprising a micro spring to maintain and compensate for reaction force and elastic deformation of a probe in contact with a semiconductor device. It is about a method.

The probe card contacts a pad on a chip implemented on a semiconductor substrate and applies an electrical signal to the pad to detect a response electric signal corresponding to the applied electrical signal to confirm whether the chip is operating normally. It is an apparatus used for the process.

Such a probe card should be able to cope with the fine pitch spacing of semiconductor devices, which are increasingly integrated as a prerequisite, and can be used in a high frequency band, so that the signal-to-response speed can be fast, and even by repeated contact. It must maintain a certain strength not to wear, maintain a predetermined contact resistance, excellent electrical conductivity, and sufficient OD (Over Drive) must be secured.

Cantilever-type probe card (cantilever-type probe card) is one of the technologies that are designed to meet these requirements, is a technique commonly used in semiconductor inspection apparatus.

As shown in FIG. 1A, the cantilever probe card 100 includes a probe substrate 110 on which a circuit pattern is implemented and a plurality of probes 120 formed on the probe substrate 110. The probe 120 may include a bump 121 formed on the connection terminal 111 of the probe substrate 110 having a predetermined circuit pattern, and a support beam 122 connected to one end of the upper surface of the bump 121 horizontally. ), A tip portion 123 protruding from the free end of the support beam 122.

FIG. 1B illustrates a state in which the tip portion 123 of the probe 120 and the pad 201 formed on the semiconductor device 200 are in contact with each other in the process of inspecting the semiconductor device using the cantilever-type probe card 100. Drawing. The pad 201 of the semiconductor device 200 reacts with oxygen in the air to form a natural oxide film on the surface. The tip portion 123 of the probe 120 penetrates the natural oxide film and contacts the pad 201. Must be in contact with the pad 201 on the semiconductor device 200 with a constant physical force. In this contact process, an end of the support beam 122 is displaced vertically downward (ie, downward in the drawing) within a margin of the height of the bump 121, and ends of the support beam 122. The vertical displacement of is called OD (Over Drive). In fact, an error exists in the height H between the plurality of pads 201 formed on the semiconductor device 200. All the probe tip parts 123 on the probe card 100 and the semiconductor device 200 corresponding thereto are provided. In order for all the pads 201 on () to contact at the same time, a mechanism for generating a spare displacement, that is, OD, is required for the probe 120, and the cantilever probe card satisfies such a mechanism as shown in the contact state of FIG. 1B. It has a structure. Meanwhile, the deformation of the probe 120 should be elastic while the OD is generated, and the probe 120, which has been deformed at the time of extinction of the external force, should be returned to its original position.

However, the cantilever-type probe card 100 as described above should have a structure that can penetrate the oxide film formed on the surface of the pad 201 of the semiconductor chip while the tip portion 123 secures a certain OD. The following problems exist. That is, in order for the tip part 123 to have a physical force that can penetrate the oxide film on the surface of the pad 201 and contact each other, the deformation strength of the support beam 122 supporting the tip part 123 must be high. The length of the support beam 122 should be shortened. However, if the length of the support beam 122 is shortened, there is a problem that the amount of vertical elastic deformation decreases, making it difficult to secure a predetermined OD, and plastic deformation beyond the elastic limit. The problem is that the probe may not be able to function as a probe. In addition, there is a problem that excessive stress is applied to the support beam 122 when the tip portion 123 and the pad 201 are contacted and broken.

In order to solve this problem, the applicant attaches an armrest to the support beam in patent application 2002-68402, "Electrical Contact for Electronic Device Inspection," filed November 6, 2002, or an armrest to the probe substrate. Proposed a card with a probe. However, the armrest may cause the OD range of the probe to be narrowed, thereby causing a problem that the pad is damaged due to excessive contact between the probe tip and the semiconductor device pad.

Accordingly, an object of the present invention is to provide a probe card further comprising a microspring for maintaining and supplementing the reaction force and elastic deformation of the probe in contact with the pad on the semiconductor element, thereby maintaining the OD of the probe and at the same time providing the elastic restoring force to the probe. In addition, to improve the contact performance with the pad. In addition, to minimize the damage of the pad due to the contact between the probe tip and the pad.

In order to achieve the above object, the present invention provides a probe card, comprising: a probe substrate on which a circuit pattern is implemented; A plurality of probes each having a bump formed on the probe substrate and a support beam having one end supported by the bump and a tip formed at a free end of the support beam; It provides a probe card, characterized in that it comprises a; a plurality of micro spring formed on the probe substrate in the vertical direction of the probe tip.

In addition, in order to achieve the above object, the present invention provides a method of manufacturing a probe card, comprising: a first step of forming a rectangular insulating support film in a region where a microspring is to be formed on a probe substrate; A second step of applying a sacrificial film to the remaining portions of the insulating support film except for one end of the insulating support film; A third step of coating a first metal film on the one end of the insulating support film and a second metal film having a thermal expansion coefficient lower than that of the first metal film on the first metal film; Forming a bump on the probe substrate using a passivation pattern; A fifth step of removing the passivation layer pattern and the sacrificial layer; Positioning the sacrificial substrate on which the probe is formed on the probe substrate, heating the probe substrate and the entire sacrificial substrate to bond the bumps and the probes, and at the same time, the combined first metal layer and the second metal layer form a micro spring. A sixth step; The seventh step of removing the sacrificial substrate by etching provides a probe card manufacturing method comprising a.

In addition, in order to achieve the above object, the present invention provides a method of manufacturing a probe card, comprising: a first step of forming a rectangular insulating support film in a region where a microspring is to be formed on a probe substrate; A second step of applying a sacrificial film to the remaining portions of the insulating support film except for one end of the insulating support film; A third step of coating a first metal film on the one end of the insulating support film and a second metal film having a thermal expansion coefficient lower than that of the first metal film on the first metal film; Forming a bump on the probe substrate using a passivation pattern; A fifth step of removing the passivation layer pattern and the sacrificial layer; A sixth step of heating and cooling the entire probe substrate to form a micro spring between the combined first metal layer and the second metal layer; Positioning a probe bonding silicon wafer on which the probe is formed on the probe substrate, and bonding one end portion of the probe and the bump to the space formed on the probe bonding silicon wafer by a local heating method; An eighth step of removing the wafer portion of the probe bonding silicon wafer by etching provides a method of manufacturing a probe card comprising a.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, a cantilever probe card according to the present invention includes a probe substrate 310 having a circuit pattern and a plurality of probes 320 formed on the probe substrate 310 and the probes. The tip portion 323 of the 320 is disposed in the vertical direction and consists of a micro spring 330 formed on the probe substrate 310.

The probe 320 is a bump 321 formed on the connection terminal 311 of the probe substrate 310 in which a predetermined circuit pattern is implemented, and a support beam 322 connected to one end of the upper end of the bump 321 horizontally. ), And a tip portion 323 protruding from the free end of the support beam 322.

As shown in FIGS. 3A and 3B, the micro springs 330 bond the copper film 332 and the chrome film 333 as bimetals on the probe substrate 310 coated with the silicon nitride film 301. The palladium alloy film 334 is applied after deforming into coil shape by applying heat.

4 illustrates that the tip 323 of the probe 320 and the pad 401 formed on the semiconductor device 400 are in contact with each other during the inspection of the semiconductor device using the cantilever probe card 300 according to the present invention. It is a figure which shows the state. As shown in FIG. 4, when the tip portion 323 contacts the pad 401, the support beam 322 is displaced vertically downward to generate OD. Then, the micro spring 330 at the lower end of the support beam 322 is in contact with this by the generation of OD of the support beam 322 is elastically deformed. Therefore, the elastic restoring force of the probe 320 can be compensated for without applying an excessive force to the pad 401 in contact with the tip portion 323 by the micro spring 330.

One embodiment of the method for manufacturing a cantilever probe card according to the present invention is as shown in FIGS. 5A to 5H. Referring to this, first, as shown in FIG. 5A, a rectangular silicon nitride film 501 is formed in a region where a microspring is to be formed on the probe substrate 500 on which the circuit wiring is formed. The silicon nitride film 501 may be formed by applying a protective film pattern having a rectangular space portion on the probe substrate, forming a silicon nitride film in the space portion, and then removing the protective film pattern.

Next, as illustrated in FIG. 5B, the silicon oxide film 502 is coated except for the left end of the silicon nitride film 501. The thickness of the silicon oxide film 502 is set to 0.2 to 0.4 μm.

5C, a copper film 503 is vertically applied to a left end of the silicon nitride film 501 exposed to the outside, and a middle portion of the copper film 503 extends horizontally. The coating is performed so that the T-shaped copper film 503 is formed as a whole. The thickness of the copper film 503 is 0.2 to 0.45 mu m.

Next, as illustrated in FIG. 5D, a chromium film 504 is coated on the horizontal portion of the copper film 503. The thickness of the chromium film 504 is 0.2 to 0.45 m.

Here, the copper film 503 and the chromium film 504 are bimetal, and the lower copper film 503 has a larger coefficient of thermal expansion than the chromium film 504. Therefore, it can be seen that the combination of the metal serving as the bimetal may be various combinations in addition to the copper and chromium.

After completing the above process, as shown in FIG. 5E, the photoresist pattern 505 defining a region in which the bump is to be formed is formed on the probe substrate 500, and then the bump 505a is formed by plating.

As shown in FIG. 5F, the photoresist pattern 505 is removed. Subsequently, the silicon oxide film 502 is removed by etching. In this case, the copper film 503 has the left end supported by the silicon nitride film 501 and the horizontal portion on the right thereof is in the air.

Next, as shown in FIG. 5G, the sacrificial substrate 600 on which the support beam 601 and the tip portion 602 are formed is positioned on the probe substrate 500, and the probe substrate 500 and the sacrificial substrate 600 are positioned. The whole is heated to about 400 ° C. to bond one end of the bump 505a and the support beam 601. Here, the bonding is made by solder paste. Meanwhile, in the process of heating the probe substrate 500, the horizontal portion of the copper film 503 and the chromium film 504 applied to the upper portion of the probe substrate 500 are bent like a coil due to a difference in thermal expansion coefficient. For reference, the coiling process is performed when the melting point of the two metals reaches the recrystallization temperature of the lower material.

Finally, as shown in FIG. 5H, the sacrificial substrate 600 is removed by etching to complete the manufacture of the probe card with the micro spring. As an additional step, chemical vapor deposition (CVD) or the like of an elastic curing agent 506, for example, a palladium alloy, is formed on the surfaces of the copper film 503 and the chromium film 504 coiled as a single piece. The springs 503 and 504 can be protected by forming by electroplating. The thickness of the said palladium alloy is 3-12 micrometers.

Another embodiment of the manufacturing method of the cantilever probe card according to the present invention, after performing the process described in Figures 5a to 5f in the same manner as in the above embodiment, performing the process shown in Figures 6a to 6c It consists of

Therefore, first, the photoresist pattern 505 and the silicon oxide film 502 are removed in FIG. 5F, and then the entirety of the probe substrate 500 is heated to about 400 ° C. as shown in FIG. 6A. The chromium film 504 applied to the portion and its upper portion is bent like a coil due to the difference in the coefficient of thermal expansion. Then, an elastic curing agent 506, for example, a palladium alloy, is deposited on the surfaces of the copper film 503 and the chromium film 504 coiled as a single body by chemical vapor deposition (CVD) or electroplating. To form.

Next, as shown in FIG. 6B, the probe bonding silicon wafer 700 having the support beam 701 and the tip portion 702 is positioned on the probe substrate 500. The probe bonding method by the local heating method using the probe bonding silicon wafer and the laser which will be described later is as described in Patent Application No. 2004-43676 filed by the present applicant on June 14, 2004.

Here, a space portion 703 is formed in the probe bonding silicon wafer 700, and one end of the support beam 701 protrudes from the space portion 703. Therefore, one end of the protruding support beam 701 is brought into contact with the bump 505a of the probe substrate 500. Then, the laser 801 is scanned from the laser light source 800 through the space 703 to locally bond one end of the support beam 701 and the bump 505a protruding from the space 703 to be bonded. Let's do it. In this case, prior to contact between the probe substrate 500 and the probe bonding silicon wafer 700, a solder paste must first be applied onto the bumps 505a.

Finally, as shown in FIG. 6C, when the bonding of all the support beams 701 and the bumps 505a is completed in the above process, the wafer portion of the probe bonding silicon wafer 700 is removed by etching. Complete the manufacture of the probe card.

As described above, according to the present invention, when a micro spring is provided on the probe card so that the semiconductor pad and the probe are in contact with each other and OD occurs in the probe, the micro spring is in contact with the support beam of the probe to support it. Since the micro spring is easily elastically deformed and restored, there is an effect of minimizing damage to the pad contacting the tip while maintaining the OD of the probe.

In addition, the micro spring supports the probe support beam, thereby preventing the elastic support force from being lost due to repeated deformation of the probe support beam.

Claims (16)

In the probe card, A probe substrate on which a circuit pattern is implemented; A plurality of probes each having a bump formed on the probe substrate and a support beam having one end supported by the bump and a tip formed at a free end of the support beam; And a plurality of micro springs disposed in the vertical direction of the probe tip and formed on the probe substrate. The method of claim 1, wherein the micro spring, Probe card, characterized in that made of bimetal. The method of claim 2, wherein the bimetal, A probe card comprising copper and chromium. The method of claim 1, wherein the micro spring, Probe card, characterized in that the elastic curing agent is applied. The method of claim 4, wherein the elastic curing agent, A probe card, characterized in that it is a palladium alloy film. In the manufacturing method of the probe card, A first step of forming a rectangular insulating support film in a region where a micro spring on the probe substrate is to be formed; A second step of applying a sacrificial film to the remaining portions of the insulating support film except for one end of the insulating support film; A third step of coating a first metal film on the one end of the insulating support film and a second metal film having a thermal expansion coefficient lower than that of the first metal film on the first metal film; Forming a bump on the probe substrate using a passivation pattern; A fifth step of removing the passivation layer pattern and the sacrificial layer; Positioning the sacrificial substrate on which the probe is formed on the probe substrate, heating the probe substrate and the entire sacrificial substrate to bond the bumps and the probes, and at the same time, the combined first metal layer and the second metal layer form a micro spring. A sixth step; And a seventh step of removing the sacrificial substrate by etching. The method of claim 6, wherein the probe card manufacturing method comprises: Probe card method further comprising the step of applying the micro-springs with an elastic curing agent. The method of claim 7, wherein the elastic curing agent, A probe card manufacturing method comprising a palladium alloy film. The method of claim 6 or 7, wherein the third step, Applying a first metal film to the one end of the insulating support film, wherein the middle portion of the first metal film extends horizontally; and And applying a second metal film having a lower coefficient of thermal expansion than the first metal film on the middle horizontal portion of the first metal film. In the manufacturing method of the probe card, A first step of forming a rectangular insulating support film in a region where a micro spring on the probe substrate is to be formed; A second step of applying a sacrificial film to the remaining portions of the insulating support film except for one end of the insulating support film; A third step of coating a first metal film on the one end of the insulating support film and a second metal film having a lower coefficient of thermal expansion than the first metal film on the first metal film; Forming a bump on the probe substrate using a passivation pattern; A fifth step of removing the passivation layer pattern and the sacrificial layer; A sixth step of heating and cooling the entire probe substrate to form a micro spring between the combined first metal layer and the second metal layer; Positioning a probe bonding silicon wafer on which the probe is formed on the probe substrate, and bonding one end portion of the probe and the bump to the space formed on the probe bonding silicon wafer by a local heating method; And an eighth step of removing the wafer portion of the probe bonding silicon wafer by etching. The method of claim 10, An intervening step between the sixth and seventh steps, further comprising applying the micro spring with an elastic curing agent. The method of claim 11, wherein the elastic curing agent, A probe card manufacturing method comprising a palladium alloy film. The method of claim 10 or 11, wherein the third step, Applying a first metal film to the one end of the insulating support film, wherein the middle portion of the first metal film extends horizontally; and And applying a second metal film having a lower coefficient of thermal expansion than the first metal film on the middle horizontal portion of the first metal film. The method of claim 6 or 10, wherein the first metal film and the second metal film, Probe card manufacturing method, characterized in that each of the copper film and chromium film. The method of claim 6 or 10, wherein the insulating support film, Probe card manufacturing method, characterized in that the silicon nitride film. The method of claim 6 or 10, wherein the sacrificial film, Probe card manufacturing method, characterized in that the silicon oxide film.

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