Method for manufacturing a probe

Abstract

To provide a probe manufacturing method capable of reducing a decrease in measurement quality.SOLUTION: A probe manufacturing method includes: forming a sheet for release and a first resist film on an upper surface of a base material in this order; removing a part of the first resist film by etching; laminating on the surface of an exposed sheet and the first resist film an external conductive film and an internal insulation film in this order; removing the external conductive film, the intermediate insulation film, and a central conductor laminated on the surface of the first resist film after forming the central conductor to embed a recess of the first resist film; removing an upper part of the central conductor formed in the recess of the first resist film by etching; forming the intermediate insulation film in the recess to surround the central conductor; removing the first resist film from the base material; forming the external conductive film to surround the central conductor together with the external conductive film formed on a lower surface and a lateral surface of the intermediate insulation film on the upper surface of the intermediate insulation film; removing the external conductive film and the intermediate insulation film of an end part to expose the central conductor at the end part; and releasing the external conductive film from the sheet.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a probe used for measuring electrical characteristics of a test object.

Background Art

[0002] In order to measure the electrical characteristics of a test object such as a semiconductor integrated circuit without separating it from the wafer, an electrical connection device having a probe that contacts the test object is used. For example, the probe head holds the probe in a state where the probe penetrates through a guide hole formed in the probe head (see Patent Document 1). As the probe, a conductor, a wire, a plate material, a plated product, etc. made of a metal material are used.

[0003] In the electrical connection device, the probe is arranged at a position corresponding to the inspection pad of the test object. Therefore, as the miniaturization of the semiconductor integrated circuit progresses and the arrangement interval of the inspection pads becomes narrower, the arrangement interval of the probes also becomes narrower. For this reason, as the pitch of the inspection pads becomes narrower, the probe is thinned or made thinner by reducing the diameter.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When the diameter of the probe is reduced, transmission loss occurs in the high-frequency characteristics, and the accuracy of the current withstand measurement at high frequencies decreases, resulting in a decrease in the measurement quality. An object of the present invention is to provide a method for manufacturing a probe that can reduce the decrease in the measurement quality.

Means for Solving the Problems

[0006] According to one aspect of the present invention, a release sheet and a first resist film are sequentially formed on the upper surface of a substrate. A part of the first resist film is etched away, and an external conductive film is formed on the exposed sheet and the surface of the first resist film that has not been etched. 、 Intermediate insulating film and an internal conductive film are sequentially laminated, and a central conductor is formed so as to fill the recess of the first resist film formed by etching. After that, the external conductive film, the intermediate insulating film , the internal conductive film and the central conductor deposited on the surface of the first resist film are removed, and the upper part of the central conductor formed in the recess of the first resist film above the internal conductive film and is etched away, and the upper surface of the central conductor exposed in the recess and the intermediate insulating film formed on the lower surface and side surface of the central conductor the internal conductive film and are used to surround the central conductor together with the intermediate insulating film the internal conductive film and is formed, the first resist film is removed from the substrate, and an external conductive film is formed on the upper surface of the intermediate insulating film so as to surround the central conductor together with the external conductive film formed on the lower surface and side surface of the intermediate insulating film. At the end, the external conductive film in order is removed so that the central conductor is exposed at the end, and the external conductive film is peeled off from the sheet. A method for manufacturing a probe including the above is provided. 、 Intermediate insulating film and an internal conductive film is removed, and the external conductive film is peeled off from the sheet. A method for manufacturing a probe including the above is provided.

Advantages of the Invention

[0007] According to the present invention, a method for manufacturing a probe capable of reducing a decrease in measurement quality can be provided.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the ratios of the thicknesses of each part are different from the actual ones. Also, it goes without saying that there are parts where the dimensional relationships and ratios are different between the drawings. The embodiments shown below are examples of devices and methods for embodying the technical idea of this invention, and the embodiments of this invention do not specify the materials, shapes, structures, arrangements, etc. of the components as follows.

[0010] The probe 10 according to the embodiment shown in FIG. 1 is used for measuring the electrical characteristics of a subject. The probe 10 includes a rod-shaped central conductor 11, an internal conductive film 12 covering the side surface of the central conductor 11, an intermediate insulating film 13 covering the surface of the internal conductive film 12 and surrounding the side surface of the central conductor 11, and an external conductive film 14 covering the surface of the intermediate insulating film 13.

[0011] As shown in FIG. 2, the probe 10 has a structure in which the internal conductive film 12, the intermediate insulating film 13, and the external conductive film 14 are sequentially laminated on the side surface of the central conductor 11. FIG. 2 is a cross-sectional view taken along the II-II direction of FIG. 1. The internal conductive film 12 is formed between the central conductor 11 and the intermediate insulating film 13. In FIG. 2, the probe 10 is exemplarily shown in which the cross-section perpendicular to the central axis of the central conductor 11 is rectangular.

[0012] Also, at the first end (hereinafter referred to as the "tip end 101") and the second end (hereinafter referred to as the "base end 102") of the probe 10, the central conductor 11 is exposed. The tip end 101 is the portion that contacts the subject during measurement.

[0013] The material of the central conductor 11 is a metal material such as copper (Cu) or nickel (Ni), for example. The internal conductive film 12 is a Cu film or a Ni film, for example. The intermediate insulating film 13 is a low dielectric material film such as a polyimide film, for example. The external conductive film 14 is a Cu film or a Ni film, for example. The intermediate insulating film 13 electrically insulates the central conductor 11 and the external conductive film 14.

[0014] As described above, the probe 10 has a coaxial structure in which the central conductor 11 and the external conductive film 14 face each other with the intermediate insulating film 13 interposed therebetween. The external conductive film 14 functions as an electromagnetic shield. Therefore, according to the probe 10, when an electrical signal of high frequency propagates through the probe 10, the transmission characteristics of the electrical signal and the loss of withstand current can be reduced.

[0015] The probe 10 is manufactured by, for example, a photolithography technique described later. The diameter of the probe 10 is, for example, about 50 μm.

[0016] On the other hand, when the diameter of the probe in the comparative example that directly uses a metal material such as a Cu material or a Ni material is made approximately the same as the diameter of the probe 10, losses occur in the transmission characteristics and current-carrying capacity of the electrical signal propagating through the probe at high frequencies, resulting in a deterioration of the measurement quality. However, according to the probe 10 having a coaxial structure, the deterioration of the measurement quality can be reduced.

[0017] FIG. 3 shows an electrical connection device 1 including a probe 10. The electrical connection device 1 is used for measuring the characteristics of a DUT 2. The DUT 2 is, for example, a semiconductor integrated circuit formed on a semiconductor substrate. The electrical connection device 1 includes a probe head 20 that holds the probe 10 with the tip portion 101 facing the DUT 2, and a wiring substrate 30. Although FIG. 3 shows four probes 10 held by the probe head 20, it goes without saying that the number of probes 10 is not limited to four.

[0018] As shown in FIG. 3, the probe 10 penetrates the probe head 20. The base end portion 102 of the probe 10 is connected to a land 31 disposed on the wiring substrate 30. The land 31 is made of a conductive material such as metal, and is electrically connected to an inspection device (not shown) such as a tester. An electrical signal propagates between the inspection device and the DUT 2 via the electrical connection device 1. The wiring substrate 30 is, for example, a printed circuit board (PCB) or an interposer (IP) substrate.

[0019] The base end portion 102 of the probe 10 that contacts the land 31 has the center conductor 11 exposed. Therefore, the inspection pad of the DUT 2 and the land 31 are electrically connected via the center conductor 11 of the probe 10.

[0020] The probe head 20 has a plurality of guide plates each forming a guide hole through which the probe 10 passes. For example, the probe head 20 shown in FIG. 4 has a plurality of guide plates arranged along the axial direction of the probe 10, with the top guide plate 21 facing the wiring board 30 as the upper stage and the bottom guide plate 22 facing the object to be inspected 2 as the lower stage. A spacer 23 arranged between the outer edge region of the top guide plate 21 and the outer edge region of the bottom guide plate 22 constitutes an intermediate region 200 through which the probe 10 passes inside the probe head 20.

[0021] Furthermore, the probe head 20 shown in FIG. 4 has a first middle guide plate 24 and a second middle guide plate 25 through which the probe 10 passes, arranged between the top guide plate 21 and the bottom guide plate 22. The first middle guide plate 24 is arranged in a region close to the top guide plate 21, and the second middle guide plate 25 is arranged in a region close to the bottom guide plate 22. Hereinafter, the guide plates arranged between the top guide plate 21 and the bottom guide plate 22, such as the first middle guide plate 24 and the second middle guide plate 25, are also referred to as "middle guide plates".

[0022] Note that, when viewed from the normal direction of the main surface of the top guide plate 21 (hereinafter referred to as "plan view"), the positions of the guide holes of the top guide plate 21 and the bottom guide plate 22 through which the same probe 10 passes are offset in a direction parallel to the main surface. Due to such an arrangement of the guide holes (offset arrangement), the probe 10 bends by elastic deformation in the intermediate region 200. Therefore, when the probe 10 contacts the object to be inspected 2, the probe 10 buckles, and the probe 10 contacts the object to be inspected 2 with a predetermined pressing force.

[0023] The top guide plate 21, bottom guide plate 22, and spacer 23 are made of an insulating material such as ceramic. The first middle guide plate 24 is a conductive guide plate (hereinafter referred to as "conductive guide plate") using a conductive film such as a metal film. The second middle guide plate 25 is a film such as resin. By using a conductive guide plate for the first middle guide plate 24, the external conductive films 14 of the plurality of probes 10 held by the probe head 20 are electrically connected to each other.

[0024] By electrically connecting the first middle guide plate 24 to the GND terminal outside the probe head 20, the first middle guide plate 24 is set to the ground potential. When the first middle guide plate 24 set to the ground potential contacts the external conductive film 14 of the probe 10, a shielding effect in the probe 10 can be obtained.

[0025] When the probe head 20 holds a probe of a comparative example that is a single metal, in order to prevent a short circuit between the probes, an insulating material such as a polyimide film is used for all the middle guide plates including the first middle guide plate 24. However, since the probe 10 has a coaxial structure, a conductive guide plate can be used for the first middle guide plate 24. With a conductive guide plate having higher rigidity than a resin film by using a conductive film such as a metal film, the replacement of the probe 10 in the electrical connection device 1 including the operation of passing the probe 10 through the through hole formed in the middle guide plate is easy.

[0026] Also, as shown in FIG. 5, the probe head 20 may include a stiffener 26 made of a metal material through which the probe 10 passes, similar to the guide plate. The probe 10 passes through a through hole formed in the stiffener 26. The stiffener 26 functions as a reinforcing plate for improving the mechanical strength of the probe head 20. Further, the stiffener 26 is also used for positioning and fixing the guide plate before and after the offset arrangement.

[0027] Furthermore, the stiffener 26 functions as an auxiliary plate when grounding the conductive guide plate. As shown in FIG. 5, the end of the conductive guide plate 27 disposed at the boundary between the stiffener 26 and the bottom guide plate 22 is drawn out to the outside of the probe head 20 and connected to the GND terminal 32 of the wiring board 30. The stiffener 26 is in contact with the conductive guide plate 27, and the external conductive film 14 of the probe 10 is grounded through the stiffener 26 and the conductive guide plate 27. By grounding the conductive guide plate 27, the stiffener 26 in contact with the conductive guide plate 27 also exhibits a shielding effect in the probe 10. Note that the conductive guide plate 27 may be disposed at the boundary between the stiffener 26 and the top guide plate 21. Since the through-hole of the stiffener 26 is longer than the through-hole of the conductive guide plate 27, the probe 10 can surely make electrical contact with the stiffener 26 in the through-hole of the stiffener 26, and the probe 10 can be set to the ground potential more surely.

[0028] FIG. 6 shows an example of the conductive guide plate. The conductive guide plate shown in FIG. 6 has a structure in which a first metal film 201, a resin film 202, and a second metal film 203 are laminated. The first metal film 201 and the second metal film 203 are metal films such as a Cu film, a Ni film, and a titanium film, for example. The resin film 202 is a low dielectric material film such as a polyimide film, for example.

[0029] The guide hole through which the probe 10 of the conductive guide plate penetrates has a structure that facilitates contact between the metal film of the conductive guide plate and the external conductive film 14 of the probe 10. For example, a shape in which the metal film projects inward from the outer edge of the guide hole is used. Specifically, as illustrated in FIG. 7, a star-shaped or cross-shaped guide hole is formed in the first metal film 201 or the second metal film 203 so as to cover a part of the rectangular guide hole formed in the resin film 202 in a plan view.

[0030] Figs. 8(a) to 8(d) show examples of the shape of the probe 10. The probes 10 shown in Figs. 8(a) and 8(b) have a shape in which the convex portions formed on the side surfaces are thicker than the inner diameter of the guide holes of the guide plate. Therefore, with the convex portions caught on the guide plate, the probe head 20 holds the probe 10. The probes 10 shown in Figs. 8(c) and 8(d) have a shape in which the concave portions formed on the side surfaces are thinner than the inner diameter of the guide holes of the guide plate, and the portions other than the concave portions are thicker than the inner diameter of the guide holes. Therefore, with the concave portions penetrating the guide holes of the guide plate, the probe head 20 holds the probe 10.

[0031] Therefore, according to the probes 10 shown in Figs. 8(a) to 8(d), it is possible to prevent the probe 10 from falling out of the guide plate. For example, the positions of the convex portions and the concave portions formed on the side surfaces of the probe 10 are set according to the position of the conductive guide plate of the probe head 20.

[0032] Hereinafter, a method for manufacturing the probe 10 will be described with reference to the drawings. Note that the method for manufacturing the probe 10 described below is an example, and it can be realized by various other manufacturing methods including this modification example.

[0033] First, as shown in Fig. 9, a peeling sheet 110 is adhered to the upper surface of the base material 100. As the sheet 110, a sheet that can be easily peeled from the base material 100 by a solvent such as isopropyl alcohol (IPA) is used.

[0034] As shown in Fig. 10, a first resist film 121 is formed on the sheet 110. The film thickness of the first resist film 121 is set corresponding to the diameter of the probe 10. Then, as shown in Fig. 11, a part of the first resist film 121 is etched and removed using photolithography technology. Fig. 12 shows a plan view after patterning the first resist film 121. The first resist film 121 is patterned according to the shape seen from the side surface of the probe 10.

[0035] Next, as shown in FIG. 13, an external conductive film 14 is formed on the surface of the exposed sheet 110 and the surface of the first resist film 121. For example, a copper film or a Ni film is formed as the external conductive film 14 by sputtering. Further, as shown in FIG. 14, an intermediate insulating film 13 is formed on the surface of the external conductive film 14 by sputtering or the like. The intermediate insulating film 13 is, for example, a polyimide film. Then, as shown in FIG. 15, an internal conductive film 12 is formed on the surface of the intermediate insulating film 13 by sputtering or the like. The internal conductive film 12 is, for example, a Cu film.

[0036] As shown in FIG. 16, the recess of the first resist film 121 is filled with a Ni film to form the central conductor 11. For example, the internal conductive film 12 is used as an electrode for plating, and the central conductor 11 is formed by an electrolytic plating method. Then, as shown in FIG. 17, the Ni film, the external conductive film 14, the intermediate insulating film 13, and the internal conductive film 12 deposited on the upper surface of the first resist film 121 are removed by planar polishing.

[0037] Next, after forming the second resist film 122 over the entire surface, a part of the second resist film 122 is removed using photolithography technology so that the upper surface of the central conductor 11 is exposed as shown in FIG. 18. Then, using the second resist film 122 as an etching mask, the upper part of the exposed central conductor 11 and the upper part of the internal conductive film 12 are etched and removed as shown in FIG. 19.

[0038] As shown in FIG. 20, the internal conductive film 12 and the intermediate insulating film 13 are formed on the upper surface of the central conductor 11. Then, as shown in FIG. 21, the first resist film 121 and the second resist film 122 are removed.

[0039] Next, as shown in FIG. 22, a metal mask 130 for sputtering is arranged such that the opening of the metal mask 130 is located above the central conductor 11. Then, using the metal mask 130 as a sputtering mask, an external conductive film 14 is formed on the upper surface of the intermediate insulating film 13 by sputtering as shown in FIG. 23. As described above, the external conductive film 14 is formed using a dry plating method.

[0040] Thereafter, an etching resist 140 is formed over the entire surface. Then, as shown in the plan view of FIG. 24, the etching resist 140 above the tip portion 101 and the base end portion 102 of the probe 10 is removed using photolithography technology. Next, using the etching resist 140 as an etching mask, the external conductive film 14, the intermediate insulating film 13, and the internal conductive film 12 are etched away. As a result, as shown in FIG. 25, the central conductor 11 is exposed at the tip portion 101 and the base end portion 102 of the probe 10.

[0041] Thereafter, the etching resist 140 is removed. Then, the sheet 110 is peeled off, and the probe 10 is completed. As described above, the probe 10 can be manufactured using the MEMS process.

[0042] According to the above manufacturing method, by laminating an insulating film and a thin film plating film on the surface of the central conductor 11, a coaxial structure probe 10 having a shielding effect can be manufactured without significantly increasing the outer diameter compared to the probe of the comparative example which is a single metal. However, due to limitations such as the film thickness and aspect ratio of the resist film that can be formed by photolithography technology, the diameter of the probe 10 is limited. For example, the diameter of the probe 10 is about 50 μm. Also, considering the assembly at the probe head 20, the total length of the probe 10 is, for example, about 2 to 3 mm.

[0043] In order to make the probe 10 have a coaxial structure, the intermediate insulating film 13 is formed. However, once insulated, the current will not flow. Therefore, in the above manufacturing method, an internal conductive film 12 is formed as a thin conductive film for energization on the surface of the central conductor 11, and the central conductor 11 is formed by the electroplating method. For example, with the internal conductive film 12 being a Cu film, the central conductor 11 is formed as a Ni film by the electroplating method.

[0044] In the above, an example using a Ni material for the material of the central conductor 11 has been described. However, a Cu material may be used for the material of the central conductor 11. Also, the central conductor 11 does not have to be a single material.

[0045] For example, as shown in FIG. 26, the central conductor 11 may have a structure in which a first region 111 made of Cu, a second region 112 made of Ni, and a third region 113 made of Cu are laminated. Alternatively, as shown in FIG. 27, the central conductor 11 may have a structure in which a first region 111 made of Ni, a second region 112 made of Cu, and a third region 113 made of Ni are laminated. FIGS. 26 and 27 show the state of the process of forming the central conductor 11 described with reference to FIG. 16 in the manufacturing process of the probe 10 described above. In the probe 10 having the structure shown in FIG. 26 or FIG. 27, the Ni material part of the central conductor 11 contributes to strengthening the springiness of the probe 10. By using the probe 10 that can be elastically deformed, it is possible to apply an overdrive so as to press the probe 10 against the test object 2, or to apply a preload so as to press the probe 10 against the land 31. This ensures electrical connection between the test object 2, the land 31, and the probe 10.

[0046] (Other embodiments) Although the present invention has been described above by way of the embodiment, the description and drawings forming part of this disclosure should not be understood as limiting the present invention. Various alternative embodiments, examples and operating techniques will become apparent to those skilled in the art from this disclosure.

[0047] For example, although the above describes an example of the probe 10 having a rectangular cross-sectional shape, the cross-sectional shape of the probe 10 may be another polygonal shape, or the cross-sectional shape of the probe 10 may be a circle.

[0048] Thus, it goes without saying that the present invention includes various embodiments that are not described here. [Explanation of symbols]

[0049] 1...Electrical connection device 2...Subject to be inspected 10…Probe 11...Center conductor 12...Inner conductive film 13...Intermediate insulating film 14…External conductive film 20…Probe head 21…Top guide plate 22…Bottom guide plate 23…Spacer 24…First middle guide plate 25…Second middle guide plate 26…Stiffener 27…Conductive guide plate 30…Wiring board 101…Tip 102…Base end

Claims

1. A release sheet and a first resist film are sequentially formed on the upper surface of a substrate, and a part of the first resist film is etched away. An external conductive film, an intermediate insulating film, and an internal conductive film are sequentially laminated on the exposed surface of the sheet and the first resist film that has not been etched. After forming a central conductor so as to fill the recess of the first resist film formed by the etching, the external conductive film, the intermediate insulating film, the internal conductive film, and the central conductor deposited on the surface of the first resist film are removed. The upper portions of the internal conductive film and the central conductor formed in the recess of the first resist film are etched away. On the upper surface of the central conductor exposed in the recess, the internal conductive film and the intermediate insulating film are sequentially formed so as to surround the central conductor together with the internal conductive film and the intermediate insulating film formed on the lower surface and the side surface of the central conductor. The first resist film is removed from the substrate. On the upper surface of the intermediate insulating film, an external conductive film is formed so as to surround the central conductor together with the external conductive film formed on the lower surface and the side surface of the intermediate insulating film. The external conductive film, the intermediate insulating film, and the internal conductive film at the end portion are removed so that the central conductor is exposed at the end portion. The external conductive film is peeled off from the sheet. A method for manufacturing a probe.

2. The method for manufacturing a probe according to Claim 1, wherein the material of the central conductor is at least one of nickel or copper.

3. The method for manufacturing a probe according to Claim 2, wherein the central conductor has a structure in which a copper material, a nickel material, and a copper material are laminated in this order.

4. The method for manufacturing a probe according to Claim 2, wherein the central conductor has a structure in which a nickel material, a copper material, and a nickel material are laminated in this order.

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