JP7312288B2 - Potential measuring device - Google Patents

Description

The present disclosure relates to potential measuring devices.

For example, Patent Literature 1 describes a measuring device that measures electrophysiological activity of a sample to be observed using microelectrodes.

Japanese Patent Publication No. 2002-523726

The measurement apparatus described in Patent Document 1 cannot stably ensure the contact area between the microelectrode and the observed sample during measurement, and cannot prevent the contact position from changing. An object of one aspect of the present disclosure is to provide a potential measuring device capable of measuring potential changes in a living body in a physically and electrically stable manner.

A potential measuring device according to one aspect of the present disclosure includes an insulating substrate, a conductive wiring arranged on a main surface of the insulating substrate, an electrode electrically connected to the conductive wiring, and the conductive wiring. an insulating layer formed on the main surface so as to cover the main surface and having an opening for exposing the electrode; and an insulating layer provided on the exposed portion of the electrode and protruding outside the insulating layer in the thickness direction of the insulating substrate. and an insulating peripheral wall surrounding the conductor on the main surface in plan view.

A potential measuring device according to another aspect of the present disclosure includes an insulating substrate, an insulating protrusion projecting from a main surface of the insulating substrate, conductive wiring formed on the main surface, and the conductive wiring. an insulating layer formed on the main surface so as to cover and having an opening for exposing the convex portion; an electrode formed on the convex portion so as to cover the top surface of the exposed portion of the convex portion; and the electrode protrudes outward from the insulating layer in the thickness direction of the insulating substrate.

A potential measuring device according to another aspect of the present disclosure includes an insulating substrate having a recess on its main surface, a conductive wiring disposed on the main surface, electrically connected to the conductive wiring, an electrode provided on a bottom surface; an insulating layer formed on the main surface so as to cover the conductive wiring and having an opening for exposing the electrode; a conductor protruding outside the main surface in the thickness direction of the substrate.

It is a schematic plan view showing an example of a potential measuring device. FIG. 2 is a partial cross-sectional view taken along line II in FIG. 1, showing an example of the electrode structure of the first embodiment; 4 is a flow chart showing an example of a method for manufacturing the electrode structure of the first embodiment; It is a schematic diagram which illustrates a part of manufacturing method of the electrode structure of 1st embodiment. It is a figure which shows an example of the usage form of the electric potential measuring apparatus of 1st embodiment. FIG. 2 is a partial cross-sectional view taken along line II in FIG. 1, showing an example of an electrode structure according to a second embodiment; FIG. 2 is a partial cross-sectional view viewed from arrow II in FIG. 1, showing an example of a plurality of protrusions; 6 is a flow chart showing an example of a method for manufacturing an electrode structure according to a second embodiment; It is a schematic diagram which illustrates a part of manufacturing method of the electrode structure of 2nd embodiment. It is a figure which shows an example of the usage form of the electrode structure of 2nd embodiment. FIG. 2 is a partial cross-sectional view taken along line II in FIG. 1, showing an example of an electrode structure according to a third embodiment; FIG. 10 is a plan view showing an example of a conductor according to a third embodiment; 6 is a flow chart showing an example of a method for manufacturing an electrode structure according to the third embodiment; It is a schematic diagram which illustrates a part of manufacturing method of the electrode structure of 3rd embodiment. It is a figure which shows an example of the form of usage of the electric potential measuring apparatus of 3rd embodiment. FIG. 2 is a partial cross-sectional view taken along line II in FIG. 1, showing an example of an electrode structure according to a fourth embodiment; FIG. 11 is a schematic plan view showing an example of a potential measuring device of a fifth embodiment; 13 is a partial cross-sectional view taken along arrow XIII in FIG. 12, showing an example of the electrode structure of the fifth embodiment; FIG. It is a figure which shows an example of the form of usage of the electric potential measuring apparatus of 5th embodiment. It is a figure which shows an example of the form of usage of the electric potential measuring apparatus of 5th embodiment. FIG. 13 is a partial cross-sectional view viewed from arrow XIII in FIG. 12, showing an example of the potential measuring device of the sixth embodiment. It is a figure which shows an example of the usage form of the electric potential measuring apparatus of 6th embodiment. FIG. 11 is a partial cross-sectional view of FIG. 1, showing an example of a potential measuring device according to a seventh embodiment; It is a figure which shows an example of the usage form of the electric potential measuring apparatus of 7th embodiment.

Embodiments of the present disclosure will be described below with reference to the drawings. In each drawing, the same or equivalent elements are denoted by the same reference numerals, and duplicate description will not be repeated.

(First embodiment)
A potential measuring device 101 of the present embodiment will be described with reference to FIGS. 1 to 4. FIG.

FIG. 1 is a schematic plan view showing an example of the potential measuring device 101. FIG. The potential measuring device 101 includes an insulating substrate 102, conductive wiring 103, a plurality of electrode structures 104, and an insulating layer 201 (see FIG. 2). The insulating substrate 102 is made of, for example, a glass plate. Of both surfaces of the insulating substrate 102, the surface facing the side on which the biological sample 401 (see FIG. 4) is arranged is called the main surface.

In the following description, for convenience of explanation, the height direction parallel to the thickness direction of the insulating substrate 102 is also referred to as "height". The direction in which the main surface of insulating substrate 102 faces (the upward direction in FIG. 2) is the upward direction of potential measuring device 101 . The direction in which the back surface of the insulating substrate 102 faces (the downward direction in FIG. 2) is the downward direction of the potential measuring device 101 . In the potential measuring device 101 of this embodiment, the height increases as it goes upward.

Conductive traces 103 are disposed on the main surface of insulating substrate 102 and electrically connect to each of the plurality of electrode structures 104 . The conductive wiring 103 is made of, for example, ITO (Indium Tin Oxide) or Al (aluminum) alloy. Each of the plurality of electrode structures 104 is arranged exposed on the main surface of the insulating substrate 102 and includes an electrode (see FIG. 2).

FIG. 2 is a partial cross-sectional view taken along line II in FIG. As shown in FIG. 2, insulating layer 201 is formed on the main surface of insulating substrate 102 to cover conductive wiring 103 and has openings 204 exposing electrodes 202 . The insulating layer 201 is made of, for example, silicon nitride (Si ₃ N ₄ ), silicon oxide (SiO ₂ ), or the like. In this embodiment, a plurality of openings 204 are formed in the insulating layer 201 so as to be arranged in a dot matrix when viewed from above (see FIG. 1).

A plurality of electrode structures 104 are respectively disposed in the plurality of openings 204 . Each electrode structure 104 comprises an electrode 202 and a conductor 203 . The electrodes 202 and conductors 203 are laminated along the thickness direction of the insulating substrate 102 . Specifically, electrodes 202 are formed on the main surface of insulating substrate 102 within openings 204 . At least part of the electrode 202 is exposed upward from the opening 204 . The electrodes 202 are electrically connected to the conductive traces 103 . The electrodes 202 are made of, for example, Ta (tantalum), Mo (molybdenum), Al (aluminum), or alloys thereof.

The conductor 203 is provided on the exposed portion of the electrode 202 and protrudes outward (that is, upward) from the insulating layer 201 in the thickness direction of the insulating substrate 102 . In other words, conductor 203 protrudes to a position higher than insulating layer 201 with respect to the main surface of insulating substrate 102 in the height direction parallel to the thickness direction of insulating substrate 102 .

The insulating layer 201 includes a wiring covering portion 201A that covers the conductive wiring 103, an electrode covering portion 201B that covers the periphery of each electrode 202, and a reference portion 201C that is in direct contact with the insulating substrate . The wire covering portion 201A and the electrode covering portion 201B swell upward from the reference portion 201C. Therefore, the height of each surface of the wire covering portion 201A and the electrode covering portion 201B is greater than the height of the surface of the reference portion 201C. A portion of the reference portion 201C surrounding each electrode structure 104 is referred to as an electrode surrounding portion 201D. The electrode surrounding portion 201D includes the entire electrode structure 104 and extends outside the electrode structure 104 in plan view.

Among the surfaces of the insulating layer 201 , the surface of the electrode peripheral portion 201</b>D is referred to as a reference surface 210 . The farthest end of the conductor 203 from the insulating substrate 102 (that is, the upper end of the conductor 203 ) is a planar top surface 205 extending substantially parallel to the main surface of the insulating substrate 102 . For example, the distance L1 in the vertical direction (thickness direction) from the reference surface 210 to the top surface 205 is 5 μm or more. The distance L1 may be 5 μm or more and 100 μm or less.

The surface of the conductor 203 is made of a conductive material. The surface of the conductor 203 is preferably made of a material that does not chemically react and is non-toxic to living organisms. For example, the conductor 203 is made of at least one of Au (gold) and Pt (platinum). Thereby, formation of an oxide film on the conductor 203 can be prevented. In addition, since gold has a lower hardness than platinum, forming the conductor 203 from gold makes it possible to process the top surface 205 more easily than from platinum.

Furthermore, the area of the top surface 205 is larger than the area of the electrode 202 in plan view. In other words, the projected area of the conductor 203 in the height direction is larger than the projected area of the electrode 202 in the height direction. Conductor 203 illustrated in FIG. 2 has a tapered shape that tapers from top surface 205 toward the main surface of insulating substrate 102 . As a result, the entire electrode 202 is arranged below the top surface 205, so that the entire electrode 202 is covered with the top surface 205 in a plan view.

FIG. 3A is a flow chart showing an example of a method for manufacturing the electrode structure 104 of this embodiment. FIG. 3B is a schematic diagram illustrating a part of the method for manufacturing the electrode structure 104 illustrated in FIG. 3A. It should be noted that the plurality of electrodes 202 and the conductive wiring 103 are patterned on the insulating substrate 102 in the pre-process of the manufacturing method described below. Furthermore, an insulating layer 201 is laminated on the insulating substrate 102 so as to cover the plurality of electrodes 202 and the conductive wiring 103 . A plurality of openings 204 are formed in the insulating layer 201 by etching the insulating layer 201 laminated on the insulating substrate 102 so as to expose the plurality of electrodes 202 . These pre-processes should just be performed by a well-known method. The following manufacturing method is performed using the potential measuring device 101 obtained in the previous step.

First, in step S301, a columnar plating is formed on an electrode using a plating technique.

In step S302, a wedge-shaped mold 311 is pressed against the projecting end 312 of each conductive material 310 in a direction toward the main surface of the insulating substrate 102 (S3031 in FIG. 3B). The protruding ends 312 of each conductive material 310 are spread by a wedge-shaped mold 311 in a plurality of directions crossing the thickness direction of the insulating substrate 102 (S3032 in FIG. 3B). In step S<b>303 , a planar mold 313 is pressed against the projecting end 312 of each conductive material 310 in a direction toward the main surface of the insulating substrate 102 . The projecting ends 312 of the conductive materials 310 are spread by a planar mold 313 substantially parallel to the main surface of the insulating substrate 102 to form the top surface 205 (S3041 in FIG. 3B). Thereby, a conductor 203 is formed. At this time, the projecting end 312 of the conductive material 310 is widened so that the area of the conductor 203 becomes equal to or larger than the area of the electrode 202 in plan view.

Through the manufacturing process described above, the potential measuring device 101 shown in the above embodiment is obtained. Next, an example of usage of the potential measuring device 101 will be described. FIG. 4 is a diagram showing an example of usage of the potential measuring device 101 having the conductor 203 shown in FIG.

When the potential measuring device 101 measures the potential change of the biological sample 401 , each surface of the insulating layer 201 and the conductor 203 on the main surface side (that is, the upper side) of the insulating substrate 102 is immersed in the buffer solution 402 . The biological sample 401 contains at least one of biological cells and biological tissue, and is solid or gel. The buffer solution 402 is a liquid that exists around the biological sample 401 in vivo and is a conductive liquid. Buffer 402 may be extracellular fluid. For example, when the biological sample 401 is brain cells, the buffer 402 is cerebrospinal fluid, physiological saline, or the like.

Next, the biological sample 401 is placed facing the main surface of the insulating substrate 102 (that is, downward). At this time, the biological sample 401 is pressed against the plurality of conductors 203 . Since the conductor 203 is formed to protrude from the insulating layer 201 , the biological sample 401 can be brought into contact only with the top surface 205 of the conductor 203 . Thereby, the biological sample 401 can be electrically connected only to the conductor 203 .

Here, by forming the area of the top surface 205 of the conductor 203 to be equal to or larger than the area of the electrode 202, the entire electrode 202 is covered with the top surface 205 in plan view. As a result, for example, even if part of the biological sample 401 hangs downward from the edge of the top surface 205 , the hanging sample portion is prevented from coming into contact with the electrode 202 . Conductor 203 has a tapered shape tapering from top surface 205 toward the main surface of insulating substrate 102 . As a result, for example, even if part of the biological sample 401 hangs down from the edge of the top surface 205, the hanging sample portion can be prevented from contacting any part of the conductor 203 other than the top surface 205. . Therefore, the biological sample 401 can be electrically connected only to the conductor 203 more reliably.

Furthermore, since the area of the top surface 205 of the conductor 203 is formed to be larger than the area of the electrode 202, the contact area between the biological sample 401 and the conductor 203 can be increased while forming the electrode 202 small. Also, by forming the electrode 202 small, the area available for the conductive wiring 103 and the like on the main surface of the insulating substrate 102 can be increased.

In addition, when the biological sample 401 placed in the potential measuring device 101 is supported by the top surfaces 205 of the plurality of conductors 203, the biological sample 401 part of is easy to hang down. Therefore, the distance L1 from the reference surface 210 to the top surface 205 is a size (for example, 10 μm or more) such that a portion of the biological sample 401 hanging down in the electrode peripheral portion 201D does not come into contact with the reference surface 210 of the insulating layer 201. is preferred.

When the conductor 203 undergoes a chemical reaction (oxidation or the like), a substance (metal oxide or the like) that is toxic to living organisms may be formed on the surface of the conductor 203 . When the biological sample 401 contacts the top surface 205 of the conductor 203 in a state where a substance toxic to the living body is formed on the surface of the conductor 203, a substance toxic to the living body is formed on the surface of the biological sample 401. may adhere.

Further, when the metal oxide formed on the conductor 203 is separated from the conductor 203 while the electrode structure 104 is immersed in the buffer solution 402 , the buffer solution 402 may be mixed with the metal oxide. be. In this state, when the biological sample 401 is pressed against the top surface 205 of the conductor 203 , metal oxides mixed in the buffer solution 402 may adhere to the surface of the biological sample 401 .

However, by forming the conductor 203 from at least one of gold and platinum, chemical reactions on the surface can be prevented. As a result, it is possible to prevent the formation of substances that are toxic to living organisms on the surface of the conductor 203 . As a result, when the biological sample 401 comes into contact with the top surface 205 of the conductor 203, it is possible to prevent substances that are toxic to the living body from adhering to the surface of the biological sample 401. FIG. Similarly, by forming the surface of the conductor 203 with at least one of gold and platinum, it is possible to prevent substances toxic in the living body from adhering to the surface of the biological sample 401 via the buffer solution 402 .

(Modification 1)
The conductor 203 may be formed by two or more types of plating, and the outermost surface may be formed of at least one of gold and platinum. Thereby, formation of an oxide film on the conductor 203 can be prevented. As a result, for the same reason as described above, it is possible to prevent substances that are toxic in the living body from adhering to the surface of the biological sample 401 .

(Modification 2)
The top surface 205 of the conductor 203 may be plated with at least one of gold and platinum. Thereby, formation of an oxide film on the top surface 205 of the conductor 203 can be prevented. As a result, when the biological sample 401 comes into contact with the top surface 205 of the conductor 203 , it is possible to prevent substances that are toxic to the living body from adhering to the surface of the biological sample 401 .

(Second embodiment)
Next, a second embodiment will be described with reference to FIGS. 5 to 7. FIG. In each of the following embodiments, configurations and processes having substantially the same functions as those of the first embodiment will be referred to by common reference numerals, description thereof will be omitted, and differences from the first embodiment will be described.

FIG. 5A is a partial cross-sectional view taken along arrow II in FIG. 1 and shows an example of the electrode structure 104 of this embodiment. The electrode structure 104 of this embodiment includes a plurality of conductors 510 instead of the plurality of conductors 203 . A top surface 511 of a conductor 510 shown in FIG. 5A has a plurality of projections 501 in a direction substantially parallel to the thickness direction of the insulating substrate 102 .

FIG. 5B is a partial cross-sectional view taken along arrow II in FIG. 1 showing an example of the plurality of protrusions 501. FIG. A distance L2 illustrated in FIG. 5B is a distance in the vertical direction (thickness direction) from the base 503, which is the downward end of the plurality of projections 501, to the upward vertex 502 of the plurality of projections 501. As shown in FIG. In the following description, the distance L2 is referred to as the "height" of the plurality of protrusions 501 for convenience of description.

FIG. 6A is a flow chart showing an example of a method for manufacturing the electrode structure 104 of this embodiment. FIG. 6B is a schematic diagram illustrating a part of the method for manufacturing the electrode structure 104 illustrated in FIG. 6A. The following manufacturing method is performed using the potential measuring device 101 obtained in the preceding step. Since steps S301 to S303 shown in FIG. 6A are the same as steps S301 to S303 shown in FIG. 3A, detailed description thereof will be omitted.

After the process in step S303, in step S601, a mold 611 having a plurality of unevenness is pressed against projecting ends 312 of each conductive material 310 in a direction toward the main surface of insulating substrate 102 (see FIG. 6B). S6011). As a result, a plurality of irregularities corresponding to the irregularities of the mold 611 are formed on the projecting end 312 of each conductive material 310 (S6012 in FIG. 6B). Thereby, a conductor 510 is formed. Also, in step S601, a mold 611 having a plurality of grooves formed therein may be pressed against projecting ends 312 of each conductive material 310 in a direction toward the main surface of insulating substrate . As a result, a plurality of protrusions and recesses corresponding to the grooves of the mold 611 are formed on the projecting end 312 of each conductive material 310 .

Among the plurality of projections and depressions formed on the top surface 511 of the conductor 510 , the plurality of protrusions are referred to as the plurality of protrusions 501 . In this embodiment, each of the plurality of protrusions 501 has a tapered shape from the base 503 toward the apex 502 . Alternatively, the protruding end 312 of each conductive material 310 is irradiated with a laser beam toward the main surface of the insulating substrate 102 (that is, downward) to form unevenness. protrusions 501 may be formed.

Next, an example of usage of the potential measuring device 101 will be described. FIG. 7 is a diagram showing an example of usage of the potential measuring device 101 having the conductor 510 shown in FIG. 5A.

As described above, when the biological sample 401 is pressed downward against the plurality of conductors 510 , first, the biological sample 401 comes into contact with the apexes 502 of the plurality of protrusions 501 formed on the top surface 511 of each conductor 510 . do. Furthermore, when the biological sample 401 is pressed downward against the plurality of conductors 510 , the biological sample 402 moves along the plurality of projections 501 formed on the top surface 511 of each conductor 510 , and the base 503 of each projection 501 . It fits up to the position where it touches the The biological sample 401 is supported from below by a plurality of conductors 510 and is in contact with the top surface 511 of each conductor 510 without gaps formed by a plurality of irregularities. This prevents the biological sample 401 from slipping on the top surface 511 of each conductor 510 , and allows the biological sample 401 and the conductors 510 to be brought into physical and stable contact. As a result, when the biological sample 401 and the conductor 510 are electrically connected, the potential measuring device 101 can accurately measure the potential change at the same position in the biological sample 401 .

In addition, by fitting the biological sample 401 along the plurality of protrusions 501, the contact area between the biological sample 401 and the top surface 511 can be made larger than when the top surface 511 is formed flat. As a result, when the biological sample 401 and the conductor 510 are electrically connected, current crowding and variations in contact resistance in the biological sample 401 can be suppressed. Furthermore, this makes it possible to suppress local abnormal reactions when the biological sample 401 and the conductor 510 are electrically connected.

Also, the plurality of protrusions 501 preferably have a height corresponding to the elasticity of the biological sample 401 . That is, it is preferable that the heights of the plurality of projections 501 are determined according to the elasticity of the biological sample 401 to be measured for potential. The higher the elasticity of the biological sample 401 , the easier it is to fit the biological sample 402 into the plurality of protrusions 501 when the biological sample 401 is pressed against the plurality of conductors 510 . Therefore, the higher the elasticity of the biological sample 401, the deeper the plurality of projections 501 may be formed. In other words, the softer the biological sample 401, the deeper the protrusions 501 may be formed.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS. 8 to 10. FIG.

FIG. 8A is a partial cross-sectional view taken along arrow II in FIG. 1 and shows an example of the electrode structure 104 of this embodiment. The electrode structure 104 of this embodiment includes a plurality of conductors 810 instead of the plurality of conductors 203 . Each conductor 810 has a base portion 801 and a tip portion 802 . FIG. 8B is a plan view showing an example of the conductor 810 of this embodiment.

The pedestal portion 801 is formed in contact with the electrode 202 . Specifically, the pedestal portion 801 is formed such that the surface facing the main surface of the insulating substrate 102 (that is, the downward direction) is in contact with the electrode 202 . The pedestal 801 also has a top surface 803 extending substantially parallel to the main surface of the insulating substrate 102 in a direction opposite to the direction toward the main surface of the insulating substrate 102 (that is, upward).

The tip portion 802 is provided in the central portion of the base portion 801 in plan view, and protrudes outward from the base portion 801 in the thickness direction of the insulating substrate 102 . In other words, tip portion 802 protrudes to a position higher than pedestal portion 801 with respect to the main surface of insulating substrate 102 in the height direction parallel to the thickness direction of insulating substrate 102 . Furthermore, it has a conical shape that tapers away from the main surface of the insulating substrate 102 .

The protruding end of tip 802 is upper end surface 804 . The upper end surface 804 is a circular plane facing the same side (ie, upward) as the main surface of the insulating substrate 102 and substantially parallel to the main surface of the insulating substrate 102 . Further, the tip portion 802 has a protrusion 805 protruding from the upper end surface 804 in the height direction parallel to the thickness direction of the insulating substrate 102 . In the following description, for convenience of explanation, the distance L3 from the surface 804 of the tip portion 802 to the tip of the protrusion 805 in the thickness direction of the insulating substrate 102 is referred to as the height of the protrusion 805 .

The surface area of the conductor 810 in plan view is greater than or equal to the surface area of the electrode 202 in plan view. Therefore, the surface area of the portion of conductor 810 facing the same side as the main surface of insulating substrate 102 is greater than or equal to the surface area of electrode 202 in plan view. In other words, the projected area of the conductor 810 in the height direction is greater than or equal to the projected area of the electrode 202 in the height direction.

FIG. 9A is a flow chart showing an example of a method for manufacturing the electrode structure 104 of this embodiment. FIG. 9B is a schematic diagram illustrating a part of the method for manufacturing the electrode structure 104 illustrated in FIG. 9A.

The following manufacturing method is performed using the potential measuring device 101 obtained in the preceding step. A wire 913 is inserted into the cylindrical body 912 before executing the following manufacturing method. Specifically, both longitudinal end portions of the tubular body 912 are referred to as a first end portion 911A and a second end portion 911B. The tubular body 912 has a wire hole that extends longitudinally through the radial center of the tubular body 912 . A wire 913 is inserted into the wire hole so as to pass through the cylindrical body 912 . Here, the first end portion 911A of the tubular body 912 has a notch 914 recessed toward the second end portion 911B side. The inner wall of the notch 914 has a shape that follows the contour of the tip 802 .

In step S901, the ball-shaped portion 910 is formed at the tip of the wire 913 pulled out from the first end portion 911A side of the tubular body 912 by electric discharge. Ball-shaped portion 910 is made of at least one of gold and platinum.

In step S902, the ball-shaped portion 910 is pressed against the top surface 803 in the direction toward the main surface of the insulating substrate 102 (that is, downward) with the housing 912, and is bonded by heat and ultrasonic waves (S9011 in FIG. 9B). . For example, when the electrodes are made of Al (aluminum) and the wires 913 are made of Au (gold), a eutectic is formed by an alloy of Al and Au at the boundary between the top surface 803 and the ball-shaped portion 910. The top surface 803 and the ball-shaped portion 910 are joined together. The top surface 803 is widened so that the area of the top surface 803 is greater than or equal to the area of the electrode 202 in plan view. Thus, a pedestal portion 801 is formed.

When cylindrical body 912 is pressed against soft ball-shaped part 910 in the direction toward the main surface of insulating substrate 102 , part of ball-shaped part 910 is pushed into notch 914 formed in the inner wall of cylindrical body 912 . It is pushed into the cylindrical body 912 along the direction (S9021 in FIG. 9B). In step S903, the cylindrical body 912 and the ball-shaped portion 910 are separated by pulling the cylindrical body 912 upward. As a result, the ball-shaped portion 910 inside the cylindrical body 912 is formed on the base portion 801 with an outer shape that follows the shape of the notch 914 . As a result, the front end portion 802 having an outer shape along the shape of the notch 914 is formed on the base portion 801 (S9031 in FIG. 9B). That is, the conductor 810 of this embodiment can be formed by so-called wire bonding.

Next, an example of usage of the potential measuring device 101 will be described. FIG. 10 is a diagram showing an example of usage of the potential measuring device 101 having the conductor 203 shown in FIG. 8A.

As described above, when the biological sample 401 is pressed against the plurality of conductors 810 toward the main surface of the insulating substrate 102 (that is, downward), first, the projections 805 of each conductor 810 stick into the biological sample 401. enter. Furthermore, when the biological sample 401 is pressed downward against the plurality of conductors 810 , the biological sample 401 sticks to the projections 805 of the conductors 810 and the top surface of the pedestal portion 801 of each conductor 810 . It is fixed to a plurality of conductors 810 in contact along 803 and the side of tip 802 . Thereby, the biological sample 401 is prevented from slipping on the conductor 203, and the biological sample 401 and the conductor 810 can be physically stably brought into contact with each other. As a result, when the biological sample 401 and the conductor 810 are electrically connected, the potential measuring device 101 can measure potential changes at the same position in the biological sample 401 .

Further, the contact area between the biological sample 401 and the conductor 810 is increased by contacting the top surface 803 of the base portion 801 and the side surface of the distal end portion 802 while the biological sample 401 is stuck in the protrusion 805 . can be increased. Thereby, the contact area between the biological sample 401 and the conductor 810 can be made larger than when the top surface of the conductor 810 is formed flat. As a result, when the biological sample 401 and the conductor 810 are electrically connected, it is possible to suppress current crowding and variations in contact resistance in the biological sample 401 . Furthermore, this makes it possible to suppress local abnormal reactions when the biological sample 401 and the conductor 810 are electrically connected.

In addition, when the biological sample 401 sticks into the projection 805 , the potential measuring device 101 can measure the potential change inside the biological sample 401 . Furthermore, by adjusting the shape of the notch 914 of the cylindrical body 912, the shape of the distal end portion 802 can be easily adjusted. Thereby, the height of the protrusion 805 substantially parallel to the thickness direction of the insulating substrate 102 can be easily adjusted. Further, by adjusting the height of the projection 805, the position where the potential measuring device 101 measures the potential change inside the biological sample 401 can be easily adjusted.

Further, by forming the conductor 810 using the wire 913, the conductor 810 can be formed of at least one of gold and platinum without plating the metal. This can prevent substances that are toxic in living organisms from adhering to the surface of the conductor 810 . Moreover, when plating is applied, the plating may peel off due to an external force on the conductor 810 . When the plating peels off, there is a risk that a substance that is toxic to living organisms will be exposed on the surface of the conductor 810 . However, since the conductor 810 is not plated and is made of at least one of gold and platinum, it is possible to avoid exposure of the surface of the conductor 810 to substances that are toxic to living organisms. can. As a result, the conductor 810 can maintain a safe state for a living body for a long period of time.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG.

FIG. 11 is a partial cross-sectional view taken along arrow II in FIG. 1 and shows an example of the electrode structure 104 of this embodiment. The potential measuring device 101 of this embodiment includes a convex portion 1101 instead of the conductor 203 .

Projection 1101 is formed to protrude from the main surface of insulating substrate 102 and is insulative. For example, the convex portion 1101 is made of silicon nitride (Si ₃ N ₄ ), silicon oxide (SiO ₂ ), or the like.

Insulating layer 1102 is formed on the main surface to cover conductive line 103 and has opening 1103 exposing projection 1101 . The insulating layer 1102 is made of, for example, silicon nitride (Si ₃ N ₄ ), silicon oxide (SiO ₂ ), or the like. In this embodiment, a plurality of openings 1103 are formed in the insulating layer 1102 so as to be arranged in a dot matrix when viewed from above (see FIG. 1).

The insulating layer 1102 includes a wire covering portion 201A, a convex portion covering portion 1102B covering the periphery of each convex portion 1101, and a reference portion 201C. The wire covering portion 201A and the convex portion covering portion 1102B swell above the reference portion 201C. Furthermore, the convex covering portion 1102B rises upward from the wiring covering portion 201A. Therefore, the height of each surface of the projection covering portion 1102B is greater than the height of the surface of the wire covering portion 201A.

The convex portion 1101 protrudes outward (upward) from the insulating layer 1102 (wiring covering portion 201A) in the thickness direction of the insulating substrate 102 . Among the surfaces of the insulating layer 802 , the end portion of the wire covering portion 201</b>A (that is, the upper end portion of the wire covering portion 201</b>A) is referred to as a top surface 1110 . The end of the protrusion 1101 that is farthest from the insulating substrate 102 (that is, the upper end of the protrusion 1101 ) is a planar top surface 1111 extending substantially parallel to the main surface of the insulating substrate 102 .

The electrode 202 is formed on the convex portion 1101 so as to cover the top surface 1111 of the exposed portion of the convex portion 1101 . The electrode 202 protrudes outside the insulating layer 1102 in the thickness direction of the insulating substrate 102 . The farthest end of the electrode 202 from the insulating substrate 102 (that is, the upper end of the electrode 202 ) is a planar top surface 1112 extending substantially parallel to the main surface of the insulating substrate 102 . For example, the distance L4 in the vertical direction (thickness direction) from the top surface 1110 to the top surface 1112 is 5 μm or more. The distance L4 may be 5 μm or more and 100 μm or less.

A plurality of protrusions 1101 and conductive lines 103 are patterned on the insulating substrate 102 . Furthermore, an insulating layer 1102 is laminated on the insulating substrate 102 so as to cover the plurality of protrusions 1101 and the conductive wiring 103 . A plurality of openings 1103 are formed in the insulating layer 1102 by etching the insulating layer 1102 stacked on the insulating substrate 102 to expose the plurality of projections 1101 . An electrode 202 is laminated on the convex portion 1101 so as to cover the top surface 1111 of the convex portion 1101 .

As a result, the electrode 202 protrudes above the insulating layer 1102 by the height of the distance L4. When the biological sample 401 is pressed against the plurality of electrodes 202 toward the main surface of the insulating substrate 102 (that is, downward), the electrodes 202 are formed to protrude from the insulating layer 1102. For some reason, the biological sample 401 can be brought into contact only with the top surface 1112 of the electrode 202 . Thereby, the biological sample 401 can be electrically connected only to the electrode 202 .

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to FIGS. 12 to 15. FIG.

FIG. 12 is a schematic plan view showing an example of the potential measuring device 1201. As shown in FIG. The potential measuring device 1201 includes an insulating substrate 102 , conductive wiring 103 , multiple electrode structures 104 , an insulating layer 1301 (see FIG. 13), and multiple peripheral walls 1202 .

Each of the plurality of peripheral walls 1202 is formed to surround each electrode structure 104 on the main surface of the insulating substrate 102 in plan view. The conductive wiring 103 penetrates each peripheral wall 1202 and connects to the electrode structure 104 inside each peripheral wall 1202 in plan view. Peripheral wall 1202 is formed of an insulating material. The peripheral wall 1202 of this embodiment is made of an inorganic insulating material, such as silicon oxide or silicon nitride.

13 is a partial cross-sectional view taken along arrow XIII in FIG. 12. FIG. As shown in FIG. 13, the peripheral wall 1202 protrudes outward (that is, upward) beyond the electrodes 202 and the conductive wirings 103 in the thickness direction of the insulating substrate 102 . In other words, the peripheral wall 1202 protrudes to a position higher than the electrodes 202 and the conductive wirings 103 with respect to the main surface of the insulating substrate 102 in the height direction parallel to the thickness direction of the insulating substrate 102 .

Insulating layer 1301 is formed on the main surface of insulating substrate 102 so as to cover conductive wiring 103 and peripheral wall 1202 . The insulating layer 1301 has openings 204 that expose the electrodes 202 .

The insulating layer 1301 includes a wire covering portion 201A, an electrode covering portion 201B, a peripheral wall covering portion 1301B covering each peripheral wall 1202, and a reference portion 201C. The electrode covering portion 201B is provided inside the peripheral wall 1202 and covers the peripheral edge of the electrode 202 in plan view. The peripheral wall covering portion 1301B protrudes upward from the wiring covering portion 201A and the electrode covering portion 201B. Therefore, the height of each surface of the peripheral wall covering portion 1301B is greater than the heights of the wiring covering portion 201A and the electrode covering portion 201B.

Among the surfaces of the insulating layer 1301 , the surface of the electrode peripheral portion 201</b>D is referred to as a reference surface 1303 . The end portion of the peripheral wall covering portion 1301B that is farthest from the insulating substrate 102 (that is, the upper end portion of the peripheral wall covering portion 1301B) is a planar top surface 1304 extending substantially parallel to the main surface of the insulating substrate 102. be. For example, the distance L5 in the vertical direction (thickness direction) from the reference surface 1303 to the top surface 1304 is 5 μm or more. The distance L5 may be 5 μm or more and 100 μm or less.

A conductor 203 is provided on the exposed portion of the electrode 202 and protrudes above the insulating layer 1301 through the opening 204 . The conductor 203 protrudes outside the peripheral wall 1202 in the thickness direction of the insulating substrate 102 . In other words, conductor 203 protrudes to a position higher than peripheral wall 1202 with respect to the main surface of insulating substrate 102 in the height direction parallel to the thickness direction of insulating substrate 102 . For example, the height of the conductor 203 is within 1.1 times the height of the peripheral wall 1202 with reference to the reference plane 1303 . Alternatively, the difference between the height of the conductor 203 and the height of the peripheral wall 1202 is 100 μm or less. Here, the height of the peripheral wall 1202 is the distance L5 from the reference surface 1303 to the top surface 1304 in the thickness direction of the insulating substrate 102 .

Furthermore, the conductor 203 protrudes outward (that is, upward) from the insulating layer 1301 in the thickness direction of the insulating substrate 102 . In other words, conductor 203 protrudes to a position higher than peripheral wall covering portion 1301 with respect to the main surface of insulating substrate 102 in the height direction parallel to the thickness direction of insulating substrate 102 .

A plurality of electrodes 202 , a plurality of peripheral walls 1202 and conductive wiring 103 are patterned on insulating substrate 102 in the pre-process of the method of manufacturing electrode structure 104 of the present embodiment. An insulating layer 1301 is laminated on the insulating substrate 102 so as to cover the electrodes 202 , the peripheral walls 1202 and the conductive wiring 103 . A plurality of openings 204 are formed in the insulating layer 1301 by etching the insulating layer 1301 laminated on the insulating substrate 102 to expose the plurality of electrodes 202 . Then, using the potential measuring device 1201 obtained in the previous step, a plurality of conductive materials 301 are formed on the plurality of electrodes 202 one by one.

FIG. 14 is a diagram showing an example of usage of the potential measuring device 1001. As shown in FIG. Since the buffer solution 402 is conductive, when the electrode 202 is energized, there is a possibility that the potential change of the biological sample 401 occurs through the buffer solution 402 except for the portion where the biological sample 401 and the conductor 203 are in contact with each other. be. However, by surrounding the conductor 203 with the peripheral wall 1202, the buffer solution 402 between the peripheral wall 1202 and the conductor 203 can be reduced.

Furthermore, the narrower the distance between the peripheral wall 1202 and the conductor 203 in plan view, the less the buffer solution 402 between the peripheral wall 1202 and the conductor 203 can be. Accordingly, since the peripheral wall 1202 is insulative, it is possible to suppress the potential change of the biological sample 401 except for the portion where the biological sample 401 and the conductor 203 are in contact with each other.

In addition, the smaller the amount of buffer solution 402 between the peripheral wall 1202 and the conductor 203, the less likely the biological sample 401 is energized via the buffer solution 402 to a position away from the position where the biological sample 401 contacts the top surface 205 of the conductor 203. can. Therefore, the smaller the buffer solution 402 between the peripheral wall 1202 and the conductor 203, the more the potential change of the biological sample 401 can be suppressed except for the portion where the biological sample 401 and the conductor 203 are in contact with each other.

In addition, when the biological sample 401 is pressed against the plurality of conductors 203 toward the main surface of the insulating substrate 102 (that is, downward), the peripheral wall 1202 surrounds the conductors 203 so that the biological sample 401 is not exposed to the conductors. Only the top surface 205 of 203 and the peripheral wall 1202 can be brought into contact. Since the biological sample 401 contacts only the top surface 205 of the conductor 203 and the top surface 1304 of the peripheral wall 1202, the peripheral wall 1202 is insulative, so the biological sample 401 can be electrically connected only to the conductor 203. .

Further, when the biological sample 401 is pressed against the plurality of conductors 203 toward the main surface of the insulating substrate 102 , the peripheral wall 1202 surrounds the conductors 203 , so that the biological sample 401 is placed on the top surface 205 of the conductors 203 . , and is prevented from coming into contact with the electrode 202 . Thereby, the biological sample 401 can be electrically connected only to the conductor 203 more reliably.

Note that when the biological sample 401 has high elasticity, when the biological sample 401 is pressed against the conductor 203 toward the main surface of the insulating substrate 102, the top surface 205 of the conductor 203 of the biological sample 401 is contacted. The portion that is not exposed tends to hang down toward the main surface of the insulating substrate 102 . Therefore, when the biological sample 401 has high elasticity and is easily deformed, the difference between the top surface 205 of the conductor 203 and the top surface 1304 of the peripheral wall 1202 may be large. In other words, when the biological sample 401 has high elasticity and is easily deformed, the allowable range for the difference between the height of the conductor 203 and the height of the peripheral wall 1202 increases.

On the other hand, when the elasticity of the biological sample 401 is low, when the biological sample 401 is pressed against the conductor 203 toward the main surface of the insulating substrate 102, the biological sample 401 contacts the top surface 205 of the conductor 203. The non-stretched portion is less likely to hang down toward the main surface of insulating substrate 102 . Therefore, when the biological sample 401 has low elasticity and is difficult to deform, it is preferable that the difference between the height of the conductor 203 and the height of the peripheral wall 1202 is small.

Also, FIG. 15 shows an example of a mode of use in which a peripheral wall 1202 is applied to the potential measuring device 1201 having the conductor 203 illustrated in FIG. As shown in FIG. 15, the biological sample 401 may be pressed against the electrode 202 formed on the projection 1102 toward the main surface of the insulating substrate 102 (that is, downward). Also in the configuration shown in FIG. 15, since the peripheral wall 1202 surrounds the electrode 202, the potential measuring device 1201 can achieve the same effect as described above.

(Sixth embodiment)
Next, with reference to FIG. 16, a sixth embodiment will be described. A potential measuring device 1201 according to this embodiment includes a peripheral wall 1602 instead of the peripheral wall 1202 shown in FIG.

16 is a partial cross-sectional view taken along arrow XIII in FIG. 12. FIG.

Insulating layer 1603 is formed on the main surface of insulating substrate 102 to cover conductive wiring 103 and has openings 204 exposing electrodes 202 . Insulating layer 1603 includes wire covering portion 201A, electrode covering portion 201B, and reference portion 201C. On the surface of the insulating layer 1603, the periphery of each electrode structure 104 in the reference portion 201C is an electrode periphery portion 201D. Among the surfaces of the insulating layer 1601 , the surface of the electrode peripheral portion 201</b>D is the reference plane 210 .

The peripheral wall 1602 is made of an organic insulating material, for example, it may be made of a resin material, or it may be made of a polyimide-based material, for example. A peripheral wall 1602 is formed on the insulating layer 1603 . Specifically, the peripheral wall 1602 is formed on the reference portion 201C. The end of the peripheral wall 1602 farthest from the insulating substrate 102 (that is, the upper end of the peripheral wall 1602 ) is a top surface 1604 extending substantially parallel to the main surface of the insulating substrate 102 . For example, the distance L6 in the vertical direction (thickness direction) from the reference surface 210 to the top surface 1604 may be 5 μm or more and 100 μm or less.

The peripheral wall 1602 protrudes outward (that is, upward) from the conductor 203 in the thickness direction of the insulating substrate 102 . In other words, conductor 203 protrudes to a position higher than peripheral wall 1602 with respect to the main surface of insulating substrate 102 in the height direction parallel to the thickness direction of insulating substrate 102 . The height of the conductor 203 is within 1.1 times the height of the peripheral wall 1602 with reference to the reference plane 210 . Alternatively, the difference between the height of the conductor 203 and the height of the peripheral wall 1602 is 100 μm or less. Here, the height of the peripheral wall 1602 is the distance L6 from the reference surface 210 to the top surface 1604 in the thickness direction of the insulating substrate 102 .

FIG. 17 is a diagram showing an example of usage of the potential measuring device 1201 of this embodiment.

By forming the peripheral wall 1602 from an organic insulating material, it becomes easier to form the peripheral wall 1602 into an arbitrary shape than when the peripheral wall 1602 is formed from an inorganic insulating material, and the peripheral wall 1602 can be formed higher. becomes easier. Thereby, the difference between the position where the biological sample 401 and the conductor 203 contact and the insulating layer 201 can be made larger than when the peripheral wall 1602 is formed of an inorganic insulating material.

By increasing the difference between the contact position between the biological sample 401 and the conductor 203 and the insulating layer 201, even if a part of the biological sample 401 hangs down from the edge of the top surface 205, the hanging down can be prevented. Contact of the sample portion with the electrode 202 is suppressed. As a result, when the biological sample 401 is pressed against the plurality of conductors 203 toward the main surface of the insulating substrate 102 (that is, downward), the position where the biological sample 401 and the conductors 203 contact and the insulating layer The greater the difference from 1603, the more stable the insulation of the conductive wiring 103 can be improved.

(Seventh embodiment)
Next, a seventh embodiment will be described with reference to FIGS. 18 and 19. FIG.

18 is a partial cross-sectional view taken along arrow XIII in FIG. 12. FIG. Conductor 203 may be shaped as shown in FIG. 2, FIG. 5 or FIG. Alternatively, the structure of the electrode structure 104 may be the structure illustrated in FIG.

Insulating substrate 102 has a plurality of recesses 1801 on its main surface. In this embodiment, a plurality of openings 1804 are formed on the main surface of the insulating substrate 102 so as to be arranged in a dot matrix when viewed from above (see FIG. 12). A plurality of electrodes 202 are provided on the bottom surfaces 1802 of the plurality of recesses 1801 and electrically connected to the conductive wiring 103 . An insulating layer 1803 is formed on the main surface of insulating substrate 102 to cover conductive wiring 103 and has a plurality of openings 1804 exposing a plurality of electrodes 202, respectively.

The insulating layer 1803 includes a wire covering portion 201A, an electrode covering portion 201B, a reference portion 1803C, and an insulating layer concave portion 1803D. The reference portion 1803C is in direct contact with the insulating substrate 102 and extends substantially parallel to the surface on which the conductive wiring 103 is formed from the wiring covering portion 201A. The insulating layer recess 1803</b>D directly contacts the insulating substrate 102 and covers the surface of the recess 1801 . A portion of the insulating layer concave portion 1803D that covers the periphery of the electrode 202 is referred to as an electrode peripheral portion 1803E.

The wire covering portion 201A rises above the reference portion 1803C. Therefore, the height of each surface of the wire covering portion 201A is greater than the height of the surface of the reference portion 1803C. The electrode surrounding portion 1803E surrounds the entire electrode structure 104 and extends outside the electrode structure 104 in plan view.

Among the surfaces of the insulating layer 1803, the surface of the electrode peripheral portion 1803E is referred to as a reference surface 1810. FIG. In addition, of the surface of the wire covering portion 201A, the end farthest from the insulating substrate 102 (that is, the upper end portion of the wire covering portion 201A) has a planar shape extending substantially parallel to the main surface of the insulating substrate 102. is the top surface 1805 of the . For example, a distance L7 in the vertical direction (thickness direction) from the reference surface 1810 to the top surface 205 is 5 μm or more. The distance L7 may be 5 μm or more and 100 μm or less.

A plurality of electrode structures 104 are respectively disposed in the plurality of openings 1804 . A conductor 203 is provided over the exposed portion of the electrode 202 . The conductor 203 protrudes outward (that is, upward) from the main surface in the thickness direction of the insulating substrate 10 . Specifically, the conductor 203 protrudes outward from the top surface 1805 of the wire covering portion 201A in the thickness direction of the insulating substrate 102 . In other words, the conductor 203 is located at the upper end of the insulating layer 1803 (that is, the top surface 1805 of the wire covering portion 201A) with the main surface of the insulating substrate 102 as a reference in the height direction parallel to the thickness direction of the insulating substrate 102. protrude higher than For example, the height of the top surface 205 of the conductor 203 is within 1.1 times the height of the upper end of the insulating layer 1803 . Alternatively, the difference between the height of the conductor 203 and the height of the upper end of the insulating layer 1803 is 100 μm or less.

In the pre-process of the method for manufacturing the electrode structure 104 of this embodiment, the insulating substrate 103 is processed so as to form a plurality of recesses 1801 . An electrode 202 is patterned on the bottom surface 1802 of each of the plurality of recesses 1801 . Further, conductive traces 103 are patterned on the insulating substrate 102 . Furthermore, a plurality of electrodes 202 and conductive traces 103 are patterned on the insulating substrate 102 . Furthermore, an insulating layer 201 is laminated on the insulating substrate 102 so as to cover the plurality of electrodes 202 and the conductive wiring 103 . An insulating layer 201 stacked on an insulating substrate 102 has a plurality of electrodes 202 exposed. Then, using the potential measuring device 1201 obtained in the previous step, a plurality of conductive materials 301 are formed on the plurality of electrodes 202 one by one.

Next, an example of usage of the potential measuring device 101 of this embodiment will be described. FIG. 19 is a diagram showing an example of usage of the potential measuring device 101 of this embodiment.

When the biological sample 401 is pressed against the plurality of conductors 203 toward the main surface of the insulating substrate 102 (that is, downward), the conductors 203 are formed on the electrodes 202 formed in the recesses 1801. Thus, the biological sample 401 can be brought into contact only with the top surface 205 of the conductor 203 and the upper end portion of the insulating layer 1803 (that is, the top surface 1805 of the wire covering portion 201A). As a result, the biological sample 401 is electrically connected only to the conductor 203 for the same reason as described above.

Further, since the conductor 203 is formed on the electrode 202 formed in the recess 1801, the electrode 202 is not surrounded by the peripheral wall 1202 or the peripheral wall 1602, and the position where the biological sample 401 and the conductor 203 are in contact with each other is insulated. The difference from layer 1603 can be increased. This improves the stability of the insulation of the conductive wiring 103 for the same reason as described above.

Note that when the biological sample 401 has high elasticity and is easily deformed, for the same reason as described above, the allowable range for the difference in height between the height of the conductor 203 and the upper end of the insulating layer 1803 is limited. growing. Similarly, when the biological sample 401 has low elasticity and is difficult to deform, it is preferable that the height difference between the height of the conductor 203 and the upper end of the insulating layer 1803 is small for the same reason as described above. .

The present disclosure is not limited to the above-described embodiments. It may be replaced with a possible configuration.

Reference Signs List 10 insulating substrate 101 potential measuring device 102 insulating substrate 103 conductive wiring 104 electrode structure 201 insulating layer 201A wire covering portion 201B electrode covering portion 201C reference portion 201D electrode surrounding portion 202 electrode 203 Conductor, 204 Opening, 205 Top surface, 210 Reference surface, 310 Conductive material, 311 Mold, 312 Protruding end, 313 Mold, 401 Biological sample, 402 Buffer solution, 501 Projection, 502 Vertex, 503 Base, 510 Conductor , 511 top surface, 611 mold, 801 base portion, 802 tip portion, 803 top surface, 804 upper end surface, 805 protrusion, 810 conductor, 910 ball-shaped portion, 911A first end portion, 911B second end portion, 912 Cylindrical body 913 Wire 1101 Projection 1102 Insulating layer 1102B Projection covering 1103 Opening 1110 Top surface 1111 Top surface 1112 Top surface 1201 Potential measuring device 1202 Peripheral wall 1301 Insulating layer 1301B Peripheral wall covering Part 1303 reference surface 1304 top surface 1601 insulating layer 1602 peripheral wall 1603 insulating layer 1604 top surface 1801 recessed portion 1802 bottom surface 1803 insulating layer 1803C reference portion 1803D insulating layer recessed portion 1803E electrode surrounding portion 1804 opening, 1805 top surface, 1810 reference surface

Claims (9)

an insulating substrate;
a conductive trace disposed on the main surface of the insulating substrate;
an electrode electrically connected to the conductive wiring;
an insulating layer formed on the main surface so as to cover the conductive wiring and having an opening exposing the electrode;
a conductor provided on the exposed portion of the electrode and protruding outside the insulating layer in the thickness direction of the insulating substrate;
and an insulating peripheral wall surrounding the conductor on the main surface in a plan view. 2. The potential measuring device according to claim 1, wherein said peripheral wall is made of at least one of an organic insulating material and an inorganic insulating material. 2. The potential measuring device according to claim 1, wherein said conductor protrudes outside said peripheral wall in the thickness direction of said insulating substrate. 4. The potential measuring device according to claim 3, wherein the height of said conductor is within 1.1 times the height of said peripheral wall. 4. The potential measuring device according to claim 3, wherein the difference between the height of said conductor and the height of said peripheral wall is 100 [mu]m or less. 2. The potential measuring device according to claim 1, wherein said conductor is made of at least one of gold and platinum. an insulating substrate having recesses on its main surface;
a conductive trace disposed on the major surface;
an electrode electrically connected to the conductive wiring and provided on the bottom surface of the recess;
an insulating layer formed on the main surface so as to cover the conductive wiring and having an opening exposing the electrode;
a conductor provided on an exposed portion of the electrode and protruding outside the main surface in the thickness direction of the insulating substrate. 8. The potential measuring device according to claim 7 , wherein said conductor is made of at least one of gold and platinum. 8. The potential measuring device according to claim 7 , wherein an area of said conductor is larger than an area of said electrode in plan view.

Images