JP2021063782A - Inspection probe, method for manufacturing inspection probe, and inspection probe - Google Patents

Abstract

To provide an inspection probe that can suppress time required for test of an opto-device, a method for manufacturing the inspection probe, and an inspection device.SOLUTION: An inspection probe 20 includes: a needle part 21 of a cantilever structure having a fixed end 212 and a free end 211 electrically connected to the fixed end 212; and a light waveguide 22 formed in the needle part 21, the light waveguide having a light reception surface 221 facing a same direction as a direction that the free end 211 faces. In the inspection probe 20, the free end 211 is electrically connected to an electric signal terminal of the inspection target 3 when the inspection target 3 is inspected, and the light reception surface 221 is optically connected to an optical signal terminal of the inspection target 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to an inspection probe used for inspecting the characteristics of an inspection object, a method for manufacturing the inspection probe, and an inspection apparatus.

Using silicon photonics technology, a semiconductor element (hereinafter referred to as "opt device") in which an electric signal and an optical signal propagate is formed on a silicon substrate or the like. In order to inspect the characteristics of an opt device in a wafer state, an opt device and a measuring device such as a tester are connected by using an electric probe for propagating an electric signal and an optical probe for propagating an optical signal. For example, a probe made of a conductive material is used as an electrical probe and an optical fiber is used as an optical probe.

JP-A-2018-81948

However, performing the alignment with the opt device separately for the electrical probe and the optical probe increases the time required for the inspection. In view of the above problems, an object of the present invention is to provide an inspection probe, a method for manufacturing the inspection probe, and an inspection apparatus capable of suppressing the time required for inspection of the opt device.

According to one aspect of the present invention, a needle portion having a fixed end and a cantilever structure having a free end electrically connected to the fixed end, and an optical wave formed in the needle portion with one end face directed in the same direction as the free end. An inspection probe with a waveguide is provided.

According to another aspect of the present invention, a first clad layer is formed on the surface of the needle portion of the cantilever structure by the first photolithography step, and a part of the upper surface of the first clad layer is formed by the second photolithography step. A core portion having a higher refractive index than the first clad layer is formed, and a second clad layer having the same refractive index as the first clad layer is formed on the upper surface of the first clad layer so as to cover the core portion by a third photolithography step. A method of manufacturing the test probe to be formed is provided. An optical waveguide whose core portion is covered with a clad portion composed of a first clad layer and a second clad layer is formed on a needle portion with one end face of the optical waveguide facing in the same direction as the free end.

According to still another aspect of the present invention, the needle portion of the cantilever structure having a fixed end fixed to the substrate and a free end electrically connected to the fixed end, and the orientation of one end face are defined as the orientation of the free end. An inspection device including an inspection probe having an optical waveguide formed in the needle portion in the same manner and an optical signal transmission path optically connected to the other end surface of the optical waveguide is provided. The relative positional relationship between the free end of the needle portion and one end surface of the optical waveguide corresponds to the relative positional relationship between the electrical signal terminal and the optical signal terminal of the inspected object.

According to the present invention, it is possible to provide an inspection probe, a method for manufacturing an inspection probe, and an inspection apparatus capable of reducing the time required for inspection of an opt device.

It is a schematic diagram which shows the structure of the inspection apparatus which concerns on 1st Embodiment of this invention. It is a top view which shows the structural example of the inspection object. It is a schematic diagram which shows the structure of the inspection probe which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the shape of the light receiving surface of the inspection probe which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the other shape of the light receiving surface of the inspection probe which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the shape of the corner part of the optical waveguide of the inspection probe which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the other shape of the corner part of the optical waveguide of the inspection probe which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the other shape of the corner part of the optical waveguide of the inspection probe which concerns on 1st Embodiment of this invention. It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention (the 1). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention (the 2). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention (the 3). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention (the 4). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention (the 5). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention (the 6). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention (the 7). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention (the 8). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention (the 9). It is a schematic diagram for demonstrating another manufacturing method of the inspection probe which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the structure of the inspection probe which concerns on 2nd Embodiment of this invention. It is a side view which shows the structure of the inspection probe which concerns on 2nd Embodiment of this invention. It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 2nd Embodiment of this invention (the 1). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 2nd Embodiment of this invention (the 2). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 2nd Embodiment of this invention (the 3). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 2nd Embodiment of this invention (the 4). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 2nd Embodiment of this invention (the 5). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 2nd Embodiment of this invention (the 6). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 2nd Embodiment of this invention (the 7). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 2nd Embodiment of this invention (the 8). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on 2nd Embodiment of this invention (the 9). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on the modification of the 2nd Embodiment of this invention (the 1). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on the modification of the 2nd Embodiment of this invention (the 2). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on the modification of the 2nd Embodiment of this invention (the 3). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on the modification of the 2nd Embodiment of this invention (the 4). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on the modification of the 2nd Embodiment of this invention (the 5). It is a process drawing for demonstrating the manufacturing method of the inspection probe which concerns on the modification of the 2nd Embodiment of this invention (the 6).

Next, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the thickness ratio of each part is different from the actual one. In addition, it goes without saying that the drawings include parts having different dimensional relationships and ratios from each other. The embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the embodiments of the present invention describe the materials, shapes, structures, arrangements, etc. of the components as follows. It is not specific to the thing.

(First Embodiment)
The inspection device 1 according to the first embodiment shown in FIG. 1 is used for inspecting the characteristics of the inspection object 3. The inspection device 1 includes a substrate 10, an inspection probe 20 fixed to the substrate 10, and an optical signal transmission line 30 connected to the inspection probe 20. The substrate 10 has a configuration in which a support substrate 11 and a printed circuit board 12 are laminated.

The inspection object 3 is an opt device having an electric signal terminal on which an electric signal propagates and an optical signal terminal on which an optical signal propagates. The inspection object 3 is not particularly limited, but is, for example, a semiconductor element such as a silicon photonics device or a vertical cavity surface emitting laser (VCSEL). For example, in the inspection object 3 illustrated in FIG. 2, the electric signal terminal 301 is a signal input terminal and the optical signal terminal 302 is an example of a VCSEL of a light emitting unit. The inspection object 3 is arranged on the stage 2 with the surfaces on which the electric signal terminal 301 and the optical signal terminal 302 are formed facing the inspection probe 20.

The inspection probe 20 includes a fixed end 212 and a cantilever-structured needle portion 21 having a free end 211 electrically connected to the fixed end 212, and an optical waveguide 22 formed on the surface of the needle portion 21. Here, the surface of the needle portion 21 facing the inspection object 3 is the lower surface, the surface facing the lower surface is the upper surface, and the surface facing the upper surface from the lower surface is the side surface. For example, as shown in FIG. 3, the optical waveguide 22 is arranged on the side surface of the needle portion 21. However, the optical waveguide 22 may be arranged on the lower surface or the upper surface of the needle portion 21.

As shown in FIGS. 1 and 3, the free end 211 of the needle portion 21 of the inspection probe 20 faces the inspection object 3. One end surface of the optical waveguide 22 (hereinafter referred to as “light receiving surface 221”) faces the same direction as the free end 211, and the light receiving surface 221 faces the inspection object 3. Further, the other end surface of the optical waveguide 22 (hereinafter referred to as “connection surface 222”) is optically connected to the optical signal transmission line 30. The "optical connection" is a concept including a connection in which light is in direct contact and a connection in which light propagates in a separated region.

At the time of inspection of the inspection object 3, as shown in FIG. 3, the free end 211 of the needle portion 21 is connected to the electric signal terminal 301 of the inspection object 3, and the light receiving surface 221 of the optical waveguide 22 is the light of the inspection object 3. Optically connected to the signal terminal 302. Therefore, the optical signal L output from the inspection object 3 is incident on the light receiving surface 221 and propagates through the optical waveguide 22, and is incident on one end of the optical signal transmission path 30 from the connection surface 222. The relative positional relationship between the free end 211 and the light receiving surface 221 when viewed from above the surface of the inspection object 3 facing the inspection probe 20 (hereinafter referred to as "planar view") is the electrical signal terminal of the inspection object 3. Corresponds to the relative positional relationship between the 301 and the optical signal terminal 302.

For example, with respect to the inspection object 3 shown in FIG. 2, the free end 211 overlaps the electric signal terminal 301 and the light receiving surface 221 overlaps the optical signal terminal 302 in a plan view. In this way, the optical waveguide 22 is arranged in the needle portion 21 so that the light receiving surface 221 faces the optical signal terminal 302 in a state where the free end 211 is in contact with the electric signal terminal 301. At this time, the optical signal terminal 302 and the light receiving surface 221 face each other so that the optical signal L is incident on the light receiving surface 221 with an intensity effective for inspection.

The fixed end 212 of the needle portion 21 of the inspection probe 20 is electrically connected to the connection terminal 110 arranged on the surface of the support substrate 11 and fixed to the support substrate 11. The connection terminal 110 is connected to the internal wiring 111 arranged inside the support board 11. As the support substrate 11, for example, a multilayer wiring board such as MLO (Multi-Layer Organic) or MLC (Multi-Layer Ceramic) can be used.

The internal wiring 111 of the support substrate 11 is electrically connected to the substrate wiring 121 formed on the printed circuit board 12. The board wiring 121 is connected to the tester land 120 arranged on the printed circuit board 12. That is, the needle portion 21 is electrically connected to the tester land 120. The tester land 120 is connected to a tester (not shown).

The printed circuit board 12 is fixed to the stiffener 40, which has a higher rigidity than the printed circuit board 12. The stiffener 40 secures the mechanical strength of the printed circuit board 12, and is also used as a support for fixing the inspection probe 20.

As described above, the needle portion 21 of the inspection probe 20 is electrically connected to the tester, and an electric signal is propagated between the tester and the inspection object 3 via the needle portion 21. A conductive material is used for the needle portion 21, and a metal such as a nickel (Ni) alloy is used for the needle portion 21.

The optical signal transmission line 30, which is optically connected to the connection surface 222 of the optical waveguide 22 and one end, is connected to the O / E conversion connect 50 at the other end. The O / E conversion connect 50 converts the optical signal L propagating in the optical signal transmission line 30 into an electric signal, and transmits the electric signal to the tester. For the optical signal transmission line 30, for example, an optical fiber or the like is preferably used. As described above, the optical signal L propagates between the tester and the inspection object 3 via the optical waveguide 22.

The end of the optical signal transmission path 30 connected to the optical waveguide 22 is exposed on the lower surface of the support substrate 11 and penetrates the support substrate 11. The optical signal transmission line 30 passes through the openings provided in the printed circuit board 12 and the stiffener 40 and connects to the O / E conversion connect 50 arranged in the printed circuit board 12. The connecting surface 222 of the optical waveguide 22 may be lens-processed into a convex spherical surface to improve the light-collecting property of the optical signal L output from the connecting surface 222.

Further, the shape of the light receiving surface 221 of the optical waveguide 22 may be processed so that the light signal L output from the inspection object 3 can be easily received. For example, as shown in FIG. 4, the light receiving surface 221 may be made into a convex spherical surface by lens processing. Alternatively, as shown in FIG. 5, the light receiving surface 221 may be sharpened with the tip angle set to about 90 degrees.

The corner portion of the optical waveguide 22 can be formed into an arbitrary shape in order to suppress the transmission loss of the optical signal L. Since the optical waveguide 22 is formed by a photolithography technique as described later, it is easy to form the optical waveguide 22 in a desired shape.

For example, as shown in FIG. 6, the corner portion of the optical waveguide 22 may be R-chamfered. As a result, the light signal L is scattered at the corners and is less likely to be reflected. Alternatively, as shown in FIG. 7, the linear portions of the optical waveguide 22 may be separated from each other, and an air layer may be provided at the corner portion. Further, as shown in FIG. 8, the corner portion may be C-chamfered. By processing the corner portion into the shape shown in FIGS. 7 and 8 with high accuracy, transmission loss due to reflection of the optical signal L can be suppressed.

The inspection method using the inspection device 1 will be described below. In the inspection of the inspection object 3, the inspection object 3 and the inspection probe 20 are aligned. For this alignment, for example, the stage 2 on which the inspection object 3 is mounted on the mounting surface is moved in a direction parallel to the mounting surface, or rotated around the surface normal direction of the mounting surface as a central axis. Will be.

After that, the distance between the inspection object 3 and the inspection probe 20 is changed while the positions of the free end 211 of the needle portion 21 and the electrical signal terminal 301 of the inspection object 3 coincide with each other in a plan view. For example, the stage 2 is moved in the direction of the inspection device 1 to electrically connect the free end 211 of the needle portion 21 to the electrical signal terminal 301 of the inspection object 3. At this time, the relative positional relationship between the free end 211 of the needle portion 21 and the light receiving surface 221 of the optical waveguide 22 corresponds to the relative positional relationship between the electric signal terminal 301 and the optical signal terminal 302 of the inspection object 3. Therefore, the light receiving surface 221 faces the optical signal terminal 302.

Then, an electric signal or an optical signal propagates between the inspection object 3 and the tester via the inspection probe 20 to inspect the characteristics of the inspection object 3. For example, an electric signal transmitted from the tester is input to the electric signal terminal 301 of the inspection object 3 via the needle portion 21 of the inspection probe 20. Then, the optical signal L output from the inspection object 3 is received by the light receiving surface 221 of the optical waveguide 22. The optical signal L propagates through the optical waveguide 22 and the optical signal transmission line 30, and is converted into an electric signal by the O / E conversion connect 50. An electric signal obtained by photoelectrically converting the optical signal L is transmitted to the tester, and the characteristics of the inspection object 3 are inspected. According to the specifications of the tester, the optical signal L may be converted into an electric signal and then input to the tester as described above, or the optical signal L may be input to the tester as it is.

As described above, the needle portion 21 of the inspection probe 20 functions as an electric probe, and the optical waveguide 22 functions as an optical probe. The needle portion 21 is provided with a cavity 210 that penetrates from one side surface to the other side surface. By providing the cavity 210 in the needle portion 21, the needle portion 21 can be made elastic. Therefore, when the needle portion 21 is brought into contact with the inspection object 3, overdrive can be applied so that the needle portion 21 and the inspection object 3 can be brought into contact with each other with a predetermined needle pressure. As a result, the electrical connection between the needle portion 21 and the inspection object 3 can be ensured.

As illustrated in FIG. 3, the light receiving surface 221 is separated from the inspection object 3 in a state where the free end 211 is in contact with the surface of the inspection object 3. As a result, it is possible to prevent the inspection object 3 from being damaged by the contact with the optical waveguide 22. However, the inspection object 3 may be inspected with the light receiving surface 221 in contact with the inspection object 3.

In order to accurately inspect the inspection object 3 using the inspection device 1, when the free end 211 of the inspection probe 20 is connected to the electric signal terminal 301 of the inspection object 3, the light receiving surface 221 is the inspection object 3. It is necessary to face the optical signal terminal 302 with high position accuracy. Therefore, the accuracy of the relative positional relationship between the free end 211 and the light receiving surface 221 needs to be high.

As will be described later, the optical waveguide 22 of the inspection probe 20 is formed in the needle portion 21 by using a photolithography technique. Therefore, the optical waveguide 22 can be arranged in the needle portion 21 by increasing the accuracy of the relative positional relationship between the free end 211 and the light receiving surface 221. Therefore, by aligning the needle portion 21 with respect to the electric signal terminal 301 of the inspection object 3, the optical waveguide 22 is also aligned with the optical signal terminal 302 of the inspection object 3 at the same time. Therefore, the inspection probe 20 and the inspection object 3 can be aligned in a short time.

As described above, according to the inspection device 1 provided with the inspection probe 20, the time required for the inspection of the inspection object 3 can be suppressed. Further, the needle portion 21 and the electric signal terminal 301 of the inspection object 3 and the optical waveguide 22 and the optical signal terminal 302 of the inspection object 3 are simultaneously connected with a predetermined position accuracy. Therefore, the electrical inspection and the optical inspection of the inspection object 3 can be performed in parallel.

FIG. 1 schematically shows a case where one inspection probe 20 is used for one inspection object 3. On the other hand, depending on the configuration of the signal terminal of the inspection object 3, a plurality of inspection probes 20 may be used for the inspection of the inspection object 3 of 1. Further, by increasing the number of inspection probes 20 arranged in the inspection apparatus 1, a plurality of inspection objects 3 can be inspected at the same time.

The manufacturing method of the inspection probe 20 will be described below with reference to the drawings. First, a needle portion 21 having a cantilever structure having a fixed end 212 and a free end 211 is prepared. For example, a needle portion 21 in which the fixed end 212 to the free end 211 are integrally molded is prepared. Then, as shown in FIG. 9, the first clad layer 201 is formed on the other side surface of the needle portion 21 having one side surface fixed to the surface of the base material 200. For the first clad layer 201, for example, an epoxy-based photosensitive material is used. Here, a photocurable resin is used as the material of the first clad layer 201.

Next, as shown in FIG. 10, the mask material 61 is used to irradiate a predetermined region of the first clad layer 201 with ultraviolet rays (hereinafter, referred to as “UV exposure”). Then, as shown in FIG. 11, only the UV-exposed region of the first clad layer 201 is left on the surface of the needle portion 21 by the developing process. A part of the optical waveguide 22 is formed by the above first photolithography step.

Then, as shown in FIG. 12, the core layer 202 is formed on the upper surface of the first clad layer 201. For the core layer 202, for example, an epoxy-based photosensitive material is used as in the case of the first clad layer 201. However, as the material of the core layer 202, a material having a higher refractive index than the material of the first clad layer 201 is used. Here, a photocurable resin is used as the material of the core layer 202.

Next, as shown in FIG. 13, a predetermined region of the core layer 202 is UV-exposed using the mask material 62. Specifically, the outer edge of the UV-exposed region of the core layer 202 is set inside the outer edge of the first clad layer 201 so that the core layer 202 remains on a part of the upper surface of the first clad layer 201. Then, as shown in FIG. 14, only the UV-exposed region of the core layer 202 is left on the upper surface of the first clad layer 201 by the development process. The core portion of the optical waveguide 22 is formed by the above second photolithography step.

Next, as shown in FIG. 15, the core layer 202 and the first clad layer 201 are covered to form the second clad layer 203 having the same refractive index as the first clad layer 201. For example, the same material as the first clad layer 201 is used for the second clad layer 203. Then, as shown in FIG. 16, a predetermined region of the second clad layer 203 is UV-exposed using the mask material 63. Then, as shown in FIG. 17, the second clad layer 203 is removed by the developing process, leaving the periphery of the core layer 202. By the above third photolithography step, the second clad layer 203 is formed on the upper surface of the first clad layer 201 by covering the core layer 202.

As described above, the optical waveguide 22 whose core portion is covered with the clad portion composed of the first clad layer 201 and the second clad layer 203 is completed by using the photolithography technique. After that, the base material 200 is peeled off from the needle portion 21.

Although the case where the optical waveguide 22 is formed on the side surface of the needle portion 21 has been described above, the optical waveguide 22 may be formed on the lower surface or the upper surface of the needle portion 21 by the same photolithography technique. When the optical waveguide 22 is formed on the lower surface or the upper surface of the needle portion 21, as shown in FIG. 18, the side surface is adjacent to the needle portion 21 fixed to the surface of the base material 200, and the surface of the base material 200 is illuminated. The waveguide 22 is formed. After that, the base material 200 is peeled from the needle portion 21 and the optical waveguide 22.

The film thickness and material of the first clad layer 201, the core layer 202, and the second clad layer 203 can be arbitrarily selected according to the specifications required for the optical waveguide 22 and the like. For example, the structure and material of the optical waveguide 22 are selected so as to suppress the transmission loss of the optical signal L.

Further, as the material of the optical waveguide 22, a sheet type to which a sheet-like material is attached, a resist type to which a liquid material is applied, or the like can be used. The sheet type is easy to handle because it can be thermocompression bonded by laminating or vacuum pressing. In addition, with the sheet type, the film thickness can be controlled uniformly and with high accuracy.

As the material of the needle portion 21, a material that is not easily affected by the manufacturing process of the optical waveguide 22 is selected. For example, a Ni alloy is preferably used as the material for the needle portion 21. The Ni alloy is not affected by the heat when laminating the sheet type material when the sheet type material is used for the optical waveguide 22.

According to the method for manufacturing the inspection probe 20 described above, the optical waveguide 22 is formed on the needle portion 21 by using the photolithography technique. Therefore, the relative positions of the free end 211 of the needle portion 21 and the light receiving surface 221 of the optical waveguide 22 can be adjusted with high accuracy. According to the inspection probe 20 manufactured by using the photolithography technique, by aligning the needle portion 21 with respect to the electric signal terminal 301 of the inspection object 3, the optical waveguide 22 also has an optical signal of the inspection object 3. Aligned with respect to terminal 302. Therefore, the alignment between the inspection probe 20 and the inspection object 3 is easy. Therefore, the time required for the inspection of the inspection object 3 can be suppressed.

(Second Embodiment)
In the inspection probe 20 according to the second embodiment, as shown in FIGS. 19 and 20, the optical waveguide 22 is embedded in the surface of the needle portion 21. FIG. 19 is a cross-sectional view taken along the XIX-XIX direction of FIG. 20, and the optical waveguide 22 is embedded in the side surface of the needle portion 21. In the inspection device according to the second embodiment, the point that the optical waveguide 22 of the inspection probe 20 is embedded in the needle portion 21 is the same as that of the first embodiment in which the optical waveguide 22 is formed on the surface of the needle portion 21. different. Other configurations are the same as those of the first embodiment shown in FIG.

Hereinafter, a method for manufacturing the inspection probe 20 according to the second embodiment will be described with reference to the drawings. First, after forming the first clad layer 201 on the surface of the base material 200, the first clad is as shown in FIG. 21 by the first photolithography step similar to the method described with reference to FIGS. 10 to 11. Layer 201 is formed.

Next, after forming the core layer 202 so as to cover the first clad layer 201, a first photolithography step similar to the method described with reference to FIGS. 13 to 14 is performed, as shown in FIG. 22. The core layer 202 is left on a part of the upper surface of the clad layer 201.

Then, after forming the second clad layer 203 so as to cover the core layer 202, the core layer is subjected to a third photolithography step similar to the method described with reference to FIGS. 16 to 17, as shown in FIG. 23. The second clad layer 203 is removed leaving the periphery of 202. As a result, the optical waveguide 22 is formed on the surface of the base material 200.

Next, as shown in FIG. 24, the surfaces of the base material 200 and the optical waveguide 22 are covered to form a plating electrode film 70 to be used in the electroplating step described later. The plated electrode film 70 is, for example, a copper (Cu) film having a film thickness of about 1 μm. Then, as shown in FIG. 25, a photocurable resist film 80 is formed on the upper surface of the plated electrode film 70. Then, as shown in FIG. 26, a part of the resist film 80 is UV-exposed except for the region where the plated electrode film 70 is exposed, using the mask material 64.

Next, as shown in FIG. 27, the UV-exposed region of the resist film 80 is removed by a developing process. Then, the needle portion 21 is formed as shown in FIG. 28 by the electroplating step using the plated electrode film 70 as an electrode. The material of the needle portion 21 is, for example, a Ni alloy. After that, as shown in FIG. 29, the resist film 80 and the plated electrode film 70 remaining on the outside of the needle portion 21 are removed by etching. As described above, the inspection probe 20 in which the optical waveguide 22 is embedded in the surface of the needle portion 21 is completed.

When the base material 200 is an organic material or the like, the step of forming the plated electrode film 70 as described above is required. As the plated electrode film 70, a Cu film or the like that can be easily removed by etching is preferably used. In addition to the Cu film, a nickel film, a palladium (Pd) film, a chromium (Cr) film, or the like is used for the plated electrode film 70 depending on the application and price. The needle portion 21 may be formed by an electroless plating method or the like.

For the material of the needle portion 21, a material that is not easily affected by the manufacturing process of the inspection probe 20 is selected. For example, the Ni alloy is not affected by the chemicals that etch and remove the copper film used as the plating electrode film 70.

Although the case where the optical waveguide 22 is embedded in the side surface of the needle portion 21 has been described above, the optical waveguide 22 may be embedded in the upper surface or the lower surface of the needle portion 21. Others are substantially the same as those in the first embodiment, and duplicate description will be omitted.

<Modification example>
In the above description, the configuration in which the optical waveguide 22 embedded in the needle portion 21 is exposed on the surface of the needle portion 21 has been described, but the entire optical waveguide 22 may be embedded in the needle portion 21. An example of a method for manufacturing the inspection probe 20 in which the entire optical waveguide 22 is embedded in the needle portion 21 will be described below.

First, as shown in FIG. 30, the first clad layer 201 is formed on the upper surface of the first needle material 21A fixed to the base material 200. After that, the core layer 202 and the second clad layer 203 are formed in the same manner as described with reference to FIGS. 10 to 17, and the optical waveguide 22 is provided on the upper surface of the first needle material 21A as shown in FIG. 31. Form.

Next, as shown in FIG. 32, the surface of the base material 200, the first needle material 21A, and the optical waveguide 22 is covered to form the plated electrode film 70. Then, after forming a photocurable resist film 80 on the upper surface of the plated electrode film 70, as shown in FIG. 33, a mask material 65 is used to remove the region where the plated electrode film 70 is exposed, and then one of the resist films 80. The part is exposed to UV. Then, the region of the resist film 80 that has not been exposed to UV is removed by a developing process.

After that, the second needle material 21B is formed as shown in FIG. 34 by an electroplating step using the plated electrode film 70 as an electrode. Then, the resist film 80 and the plated electrode film 70 remaining on the outside of the first needle material 21A and the second needle material 21B are removed by etching. As described above, as shown in FIG. 35, the inspection probe 20 in which the optical waveguide 22 is embedded in the needle portion 21 composed of the first needle material 21A and the second needle material 21B is completed.

(Other embodiments)
Although the present invention has been described by embodiment as described above, the statements and drawings that form part of this disclosure should not be understood to limit the invention. Various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art from this disclosure.

For example, although the case where the optical waveguide 22 is formed by UV exposure and development processing has been described above, the optical waveguide 22 may be formed by an etching process using an etching mask patterned by a photolithography technique.

As described above, it goes without saying that the present invention includes various embodiments not described here.

1 ... Inspection device 2 ... Stage 3 ... Inspection object 10 ... Board 11 ... Support board 12 ... Printed circuit board 20 ... Inspection probe 21 ... Needle part 22 ... Optical waveguide 30 ... Optical signal transmission line 40 ... Stiffener 50 ... O / E conversion Connect 211 ... Free end 212 ... Fixed end 221 ... Light receiving surface 222 ... Connection surface 301 ... Electrical signal terminal 302 ... Optical signal terminal

Claims (9)

An inspection probe used to inspect an object to be inspected.
A needle portion of a cantilever structure having a fixed end and a free end electrically connected to the fixed end,
An inspection probe comprising an optical waveguide formed on the needle portion with one end face facing in the same direction as the free end. The inspection probe according to claim 1, wherein the optical waveguide is made of a photocurable resin. The inspection probe according to claim 1 or 2, wherein the optical waveguide is arranged on the surface of the needle portion. The inspection probe according to claim 1 or 2, wherein the optical waveguide is embedded in the needle portion. A method of manufacturing an inspection probe used for inspecting an object to be inspected.
A needle portion having a cantilever structure having a fixed end and a free end electrically connected to the fixed end is prepared.
A first clad layer is formed on the surface of the needle portion by the first photolithography step.
By the second photolithography step, a core portion having a higher refractive index than the first clad layer is formed on a part of the upper surface of the first clad layer.
By the third photolithography step, a second clad layer having the same refractive index as the first clad layer is formed on the upper surface of the first clad layer so as to cover the core portion.
An optical waveguide whose core portion is covered with a clad portion composed of the first clad layer and the second clad layer is attached to the needle portion with one end face of the optical waveguide directed in the same direction as the free end. A method of manufacturing an inspection probe, characterized in that it is formed. The method for manufacturing an inspection probe according to claim 5, wherein the first clad layer, the core portion, and the second clad layer are photocurable resins. An inspection device used for inspecting an inspection object having an electric signal terminal for propagating an electric signal and an optical signal terminal for propagating an optical signal.
With the board
A needle portion having a cantilever structure having a fixed end fixed to the substrate and a free end electrically connected to the fixed end, and one end face formed on the needle portion in the same direction as the free end. An inspection probe with an optical waveguide
An optical signal transmission line optically connected to the other end face of the optical waveguide is provided, and the relative positional relationship between the free end and the one end face is relative to the electric signal terminal and the optical signal terminal. An inspection device characterized in that it corresponds to a positional relationship. The inspection device according to claim 7, wherein the optical waveguide is made of a photocurable resin. The inspection device according to claim 7 or 8, wherein the optical waveguide is arranged on the surface of the needle portion.

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