JP2015194357A - electrochemical measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that accurate measurement for each working electrode is impossible due to difficulty in securing insulation between electrodes when measurement using a plurality of working electrodes is performed.SOLUTION: An electrochemical measurement device comprises a lower plate 1, a chip 2 provided on an upper surface of the lower plate 1, a substrate 3 provided above the chip 3, and an upper plate provided on an upper surface of the substrate 3. The chip 2 includes a working electrode provided on an upper surface thereof and a first electrode pad provided on the upper surface and electrically connected to the working electrode. The substrate 3 includes a second electrode pad provided on a lower surface thereof and electrically connected to the first electrode pad and a third electrode pad provided on the substrate 3 and electrically connected to the second electrode pad and further connected to an external terminal. The upper plate 4 and the substrate 3 have through holes 9 and 10 so as to expose the working electrode. This configuration allows accurate and easy electrical extraction from the working electrode to an external device such as a meter.

Description

  The present invention relates to an electrochemical measurement device used for the inspection and analysis of the activity state of biologically derived substances such as cells and tissues such as fertilized eggs.

  Biological substances such as cells and tissues such as fertilized eggs are active by transporting various substances between the inside and the outside. For example, a fertilized egg takes in surrounding oxygen into the cell by breathing, and divides inside the follicle while consuming the taken-in oxygen. As a means for measuring the activity state of such a biological substance, a method of electrically measuring a physicochemical state change that occurs around the biological substance is known. These are used as pharmacological tests for new drug candidate compounds using model cells and methods for measuring the activity of fertilized eggs.

  FIG. 9 is an exploded perspective view of a conventional electrochemical measurement device 100. Further, FIG. 10 shows a cross-sectional view of a part of the well 101 of the electrochemical measurement device 100. The electrochemical measurement device 100 is composed of a plate having a plurality of wells 101 that accommodate biological samples. In the electrochemical measurement device 100, the upper plate 102 and the lower plate 103 are bonded by an adhesive 104. The upper plate 102 has a through hole that forms a well 101 for accommodating a biological sample. In the lower plate 103, one set of working electrodes 105 is formed on the upper surface of the lower plate 103 for one well 101. Further, the lower plate 103 is provided with conductive vias 107 that electrically connect the working electrode 105 provided on the upper surface of the lower plate 103 and the electrode extraction portion 106 provided below the lower plate 103.

  A measurement liquid containing a biological sample is introduced into the well 101 of the electrochemical measurement device 100. At this time, a physicochemical change occurs around the biological sample according to the activity state. The electrochemical measurement device 100 electrically measures a physicochemical change that occurs around the biological sample using the working electrode 105. The current flowing through the working electrode 105 is measured by the electrode extraction portion 106 provided below the lower plate 103 through the conductive via 107. The activity state of the biological sample can be measured by electrical measurement.

  As a prior art document related to the invention of the present application, for example, Patent Document 1 is known.

Special table 2008-534965 gazette

  The conventional electrochemical measurement device 100 is configured to measure a measurement value at the working electrode 105 from an electrode extraction unit 106 provided below the lower plate 103 via a conductive via 107.

  However, when a plurality of working electrodes 105 are provided in one well 101 and measurement values are measured at the respective working electrodes 105, in the configuration of the conventional electrochemical measurement device 100, the conductive vias 107 of the lower plate 103, and In addition, the electrode extraction portion 106 provided below the lower plate 103 has a complicated configuration in which the electrodes are densely packed. Therefore, it is difficult for the conventional electrochemical measurement device 100 to ensure insulation between the working electrode 105, the conductive via 107, and the electrode extraction part 106 when performing measurement using a plurality of working electrodes 105. There is a problem that accurate measurement for each working electrode 105 cannot be performed.

  The present invention solves the above-described problems, and provides an electrochemical measurement device that can easily ensure insulation between the working electrode and the wiring and can accurately and easily realize measurement for each working electrode. Objective.

  In order to achieve the above object, an electrochemical measurement device of the present invention includes a lower plate, a chip provided on the upper surface of the lower plate, a substrate provided above the chip, and an upper plate provided on the upper surface of the substrate. Consists of.

  The chip has a working electrode provided on the upper surface and a first electrode pad provided on the upper surface and electrically connected to the working electrode. The substrate is provided on the lower surface and is electrically connected to the first electrode pad, and the substrate is provided on the substrate and is electrically connected to the second electrode pad and connected to the external terminal. A third electrode pad. Further, the upper plate and the substrate have a through hole so as to expose the working electrode.

  The electrochemical measurement device of the present invention is characterized in that electrical connection with a chip is performed by using a substrate provided with electrode pads. With such a configuration, insulation between the working electrode and the wiring can be easily ensured, and measurement for each working electrode can be performed accurately and easily.

The perspective view of the electrochemical measuring device in Embodiment 1 of this invention The perspective view which decomposes | disassembles and shows a part of electrochemical measuring device in Embodiment 1 of this invention Sectional drawing which shows typically the electrochemical measuring device in Embodiment 1 of this invention FIG. 3 is a top view schematically showing the chip in the first embodiment of the present invention. The figure which shows typically the lower surface of the board | substrate in Embodiment 1 of this invention. Sectional drawing which shows operation | movement of the electrochemical measuring device in Embodiment 1 of this invention Sectional drawing which shows typically the electrochemical measuring device in Embodiment 2 of this invention Sectional drawing which shows typically the anisotropic conductive sheet in Embodiment 2 of this invention Exploded perspective view of a conventional electrochemical measurement device Sectional drawing which shows typically a part of conventional electrochemical measuring device

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the contents described below as long as it is based on the basic characteristics described in this specification.

(Embodiment 1)
FIG. 1 is a perspective view of an electrochemical measurement device 30 in the present embodiment. FIG. 2 is an exploded perspective view showing a part of the electrochemical measurement device 30. FIG. 3 is a cross-sectional view schematically showing the electrochemical measurement device 30. 4 is a top view schematically showing the chip 2, and FIG. 5 is a diagram schematically showing the bottom surface of the substrate 3. As shown in FIG.

  The electrochemical measurement device 30 is a device for measuring the activity state of a biological substance such as a cell such as a fertilized egg or a tissue.

  The electrochemical measurement device 30 includes a lower plate 1, a chip 2 provided on the upper surface of the lower plate 1, a substrate 3 provided above the chip 2, and an upper plate 4 provided on the upper surface of the substrate 3. . The chip 2 has a working electrode 5 provided on the upper surface and a first electrode pad 6 provided on the upper surface and electrically connected to the working electrode 5. The substrate 3 is provided on the lower surface and is electrically connected to the first electrode pad 6, the second electrode pad 7 is provided on the substrate 3, is electrically connected to the second electrode pad 7, and is externally connected. And a third electrode pad 8 connected to the terminal. The upper plate 4 has a through hole 9 so as to expose the working electrode 5. The substrate 3 has a through hole 10 so as to expose the working electrode 5.

  With such a configuration, electrical extraction from the working electrode 5 to an external device such as a measuring instrument can be performed accurately and easily. Further, even in the case where measurement is performed for each of the plurality of working electrodes 5, the extraction wiring can be simply configured and measurement can be easily performed.

  The electrochemical measurement device 30 includes a chip 2, a substrate 3, a sealing material 11, an upper plate 4, and a lower plate 1.

  The chip 2 has one or more working electrodes 5 formed on the upper surface of the chip 2 and first electrode pads 6 wired from the working electrodes 5. The working electrode 5 and the first electrode pad 6 are electrically connected. Here, the first electrode pad 6 means a portion electrically connected to the second electrode pad 7 among conductor portions such as wiring provided on the chip 2. Moreover, it is desirable that the chip 2 has a mounting portion 12 that captures a biological substance. The placement unit 12 is, for example, a recess provided on the upper surface of the chip 2.

  A plurality of working electrodes 5 may be disposed on the chip 2. By providing a plurality of working electrodes 5, it is possible to measure an electrochemical change around a biological substance in a two-dimensional plane. Further, the working electrode 5 may be disposed so as to surround the placement unit 12, for example.

  For the chip 2, for example, an inorganic material such as glass, a resin such as silicon, or ceramic can be used. The working electrode 5 is preferably platinum, gold, silver or the like. The working electrode 5 can be formed on the upper surface of the chip 2 through a normal semiconductor process. Further, a minute chip 2 can be formed by a semiconductor process.

  The working electrode 5 may be covered with an insulator and partially exposed. In this case, electrochemical measurement can be performed at the exposed portion of the working electrode 5. Moreover, it is desirable that the wiring connecting the working electrode 5 and the first electrode pad 6 is covered with an insulator. By setting it as such a structure, an unnecessary contact with the working electrode 5 and a measurement liquid can be avoided, and an electrochemical measurement can be performed with sufficient precision. Further, it is possible to prevent the working electrode 5 from being deteriorated due to the measurement liquid or the like.

  As shown in FIG. 5, the substrate 3 has a second electrode pad 7 disposed so as to face the first electrode pad 6 on the chip 2. Moreover, it has the 3rd electrode pad 8 wired from the 2nd electrode pad 7 on the board | substrate 3, and arrange | positioned at the periphery of the board | substrate.

  The second electrode pad 7 and the third electrode pad 8 are formed on the lower surface side of the substrate 3. Here, the second electrode pad 7 and the third electrode pad 8 are electrically connected to the first electrode pad 6 and a connection terminal of an external device among conductor portions such as wiring provided on the substrate 3. Means the part to be The first electrode pad 6, the second electrode pad 7, and the third electrode pad 8 are preferably provided according to the number of the working electrodes 5. The third electrode pad 8 is used for electrically extracting a signal detected by the working electrode 5 to an external device such as a measuring instrument. A measuring instrument or the like can individually measure the potential and current of each working electrode 5. As an electrical extraction method of the measurement value, for example, it can be realized by using a contact probe. Further, the substrate 3 has a through hole 10 so that a part of the working electrode 5 provided on the chip 2 is exposed.

  In addition, the board | substrate 3 can select and use a printed circuit board, a flexible substrate, a lead frame board | substrate, etc. from a viewpoint of assembly ease or cost. The printed circuit board is preferable from the viewpoints of ease of assembly and cost. By using the printed circuit board, it is possible to easily realize the wiring arrangement and the electrical connection between the second electrode pad 7 and the third electrode pad 8.

  The electrical connection between the first electrode pad 6 provided on the upper surface of the chip 2 and the second electrode pad 7 provided on the lower surface of the substrate 3 is preferably performed using a conductive paste. . By using the conductive paste, the first electrode pad 6 and the second electrode pad 7 can be more reliably connected. As the conductive paste, for example, an Ag paste or the like can be used. The conductive paste can be applied to the electrode pad by a method such as dispensing or printing.

  The sealing material 11 is installed on the chip 2 and has an opening 13 so that a part of the working electrode 5 is exposed. The sealing material 11 is preferably an elastic body such as rubber or an adhesive in order to ensure liquid sealing performance. However, some adhesives have cytotoxicity against biologically derived materials such as fertilized eggs. Therefore, it is preferable to select an elastic body as the sealing material 11. As an elastic material, PDMS (polydimethylsiloxane) or silicon rubber is more desirable. Since PDMS and silicon rubber have biocompatibility, measurement can be performed in a state where the influence on biologically derived materials such as fertilized eggs is small.

  In addition, liquid sealing property can be ensured more reliably by using an elastic body whose upper and lower surfaces are mirror surfaces. For example, a mirror-finished silicon rubber can be brought into close contact with the chip 2 or the upper plate 4 without bubbles only by the adhesive property of the silicon rubber itself, and a state without a liquid leakage generation path can be realized.

  The upper plate 4 is disposed so as to contact the sealing material 11 and the substrate 3 and has a through hole 9 so that a part of the working electrode 5 is exposed. The upper plate 4 preferably has a protrusion 14 that protrudes downward from the lower surface around the through hole 9. At this time, the sum of the height of the protrusion and the height of the sealing material 11 is preferably higher than the height of the substrate 3. Since the sealing material 11 is an elastic body, it is compressed in the height direction by assembling. Therefore, the sealing material can be firmly sandwiched between the upper plate and the chip 2, and the measurement liquid does not infiltrate the upper and lower surfaces of the substrate 3 to wet the wiring and the electrode pads 6, 7, 8. Can be held. Therefore, it is possible to realize a device that secures a liquid sealing property that can be filled with a measurement liquid, and to realize an accurate electrochemical measurement. Here, the well 15 is a space including the upper surface of the chip 2, the sealing material 11, and the upper plate 4. An adhesive layer may be provided between the upper plate 4, the sealing material 11, and the substrate 3. Further, the upper plate 4 can be provided in a state of being separated from the substrate 3.

  The outer diameter d1 of the sealing material 11 is preferably smaller than the inner diameter d2 of the through hole 10 of the substrate 3 and larger than the inner diameter d3 of the through hole 9 of the upper plate 4.

  In addition, since the measurement liquid can be held in the well 15 if the gap between the upper plate 4 and the chip 2 or between the upper plate 4 and the substrate 3 and between the substrate 3 and the chip 2 can be assembled without gaps, The sealing material 11 may not be used. However, in order to ensure the liquid seal of the electrochemical measurement device 30, it is preferable to use the sealing material 11.

  The lower plate 1 has a recess 16 that holds the chip 2 and is disposed so as to contact the substrate 3. The depth of the recess 16 is preferably the same as the height of the chip 2. Thereby, the upper surface of the chip 2 and the upper surface of the lower plate 1 are flattened, and the assembly accuracy is improved.

  The upper plate 4 and the lower plate 1 are made of, for example, glass, resin, silicon, ceramic, or the like.

  The upper plate 4 and the lower plate 1 have, for example, a screw tightening portion 17 and can be assembled by screw tightening. By fixing by screw tightening, the sealing material 11 is pressurized, and the liquid-sealed well 15 is formed. The well 15 that is liquid-sealed serves as a space that holds the measurement liquid and captures a biological substance.

  Each of the upper plate 4, the lower plate 1, and the substrate 3 may have a structure having a through hole 18 for passing an assembly alignment pin. By assembling using the alignment pins as a guide, the upper plate 4, the lower plate 1, and the substrate 3 are aligned as designed. Further, the chip 2 is aligned in the recess 16 of the lower plate 1. The sealing material 11 is aligned in the through hole 10 of the substrate 3. With these configurations, all members can be easily assembled with high accuracy as designed. In addition, it is possible to realize the electrochemical measurement device 30 that ensures liquid sealability and ensures electrical connection.

  The operation of the electrochemical measurement device 30 of the present embodiment configured as described above will be described below. FIG. 6 is a cross-sectional view showing the operation of the electrochemical measurement device 30.

  The living body derived material 19 is, for example, a fertilized egg. A fertilized egg divides inside the follicle while consuming surrounding oxygen. The electrochemical measurement device 30 can confirm the oxygen consumption activity state of the fertilized egg by measuring the amount of oxygen dissolved around the fertilized egg by the working electrode 5. Since the amount of dissolved oxygen correlates with the amount of oxygen consumed as a result of the activity of the fertilized egg, the activity state of the fertilized egg can be confirmed.

  The measurement liquid 21 containing the biological substance 19 is injected into the well 15 and the biological substance 19 is placed on the mounting portion 12 provided on the chip 2. The living body material 19 uses a fertilized egg.

  Thereafter, the reference electrode 20 is inserted until it comes into contact with the measurement liquid 21. For the reference electrode 20, Ag / AgCl, Pt, Au, or the like is used.

  Then, using a plurality of working electrodes 5 and one reference electrode 20, the amount of dissolved oxygen is quantified by measuring the current between each working electrode 5 and reference electrode 20.

(Embodiment 2)
Hereinafter, an electrochemical measurement device 50 according to Embodiment 2 of the present invention will be described with reference to the drawings.

  FIG. 7 is a cross-sectional view of the electrochemical measurement device 50 in the present embodiment.

  The electrochemical measurement device 50 is different from the electrochemical measurement device 30 in the first embodiment in that an anisotropic conductive sheet is used instead of the sealing material. In addition, about what has the structure similar to the structure of Embodiment 1, the same code | symbol is attached | subjected, the description is abbreviate | omitted, and a difference is explained in full detail.

  In the electrochemical measurement device 50, the first electrode pad 6 provided on the chip 2 and the second electrode pad 7 provided on the lower surface of the substrate 3 are electrically connected via an anisotropic conductive sheet 51. ing.

  FIG. 8 shows a cross-sectional view of the anisotropic conductive sheet 51.

  The anisotropic conductive sheet 51 is a sealing material having electrical conductivity in a specific direction. The anisotropic conductive sheet 51 is, for example, an elastic body 52 including a large number of conductive thin wires 53. The conductive thin wire 53 is made of a metal or conductor such as copper, silver, or brass, and has a thickness of 100 μm or less, for example.

  A large number of thin wires 53 are oriented in a direction perpendicular to the anisotropic conductive sheet 51 inside the elastic body 52. Here, the vertical direction is a direction connecting the upper surface and the lower surface. The plurality of thin wires 53 in the elastic body 52 are insulated from each other by the elastic body 52. By using such an anisotropic conductive sheet 51, the first electrode pad 6 and the second electrode pad 7 can be easily electrically connected even if the installation position of the anisotropic conductive sheet 51 is shifted. Can do.

  In addition, the anisotropic conductive sheet 51 can simultaneously perform electrical connection between the first electrode pad 6 and the second electrode pad 7 and ensure the liquid sealability of the electrochemical measuring device 50. Man-hours can be reduced.

  The upper plate 4 preferably has a protrusion 54 that protrudes downward from the lower surface around the through hole 9. At this time, the height of the protrusion and the height of the substrate 3 are preferably the same. That is, the lower surface of the protrusion and the lower surface of the substrate 3 are preferably flat.

  The outer diameter D1 of the anisotropic conductive sheet 51 is smaller than the inner diameter D2 of the recess 16 of the lower plate 1, larger than the inner diameter D3 of the through hole 10 of the substrate 3, and larger than the inner diameter D4 of the through hole 9 of the upper plate 4. It is preferable. The depth of the recess 16 in the lower plate 1 is preferably smaller than the sum of the height of the chip 2 and the height of the anisotropic conductive sheet 51. Since the anisotropic conductive sheet 51 is an elastic body, it is compressed in the height direction by assembling. Therefore, the anisotropic conductive sheet 51 can be firmly sandwiched between the upper plate 4 and the chip 2, and good liquid sealability can be ensured.

  As described above, the electrochemical measurement device of the present invention can ensure electrical connection and liquid sealing even with a complicated configuration in which a plurality of working electrodes and wirings are close to each other. Therefore, it is possible to realize an electrochemical measurement device that can detect a minute electrical change caused by the activity of a biological material such as a fertilized egg.

  In the electrochemical measurement device of the present invention, the number of working electrodes and electrode pads can be arbitrarily determined according to the measurement object and the measurement method, and may be one or two or more. Also, the working electrode and wiring pattern provided on the top surface of the chip, the shape of the first electrode pad, the wiring pattern provided on the bottom surface of the substrate, the shape of the second electrode pad and the third electrode pad, etc. Can also be arbitrarily determined.

  In the present invention, terms indicating directions such as “upper surface”, “lower surface”, “upper”, and “lower” indicate relative directions that depend only on the relative positional relationship of the components of the electrochemical measurement device, and are vertical. It does not indicate an absolute direction such as a direction.

  The electrochemical measurement device of the present invention is useful as a device for inspecting and analyzing the activity state of a biological substance typified by a cell or tissue such as a fertilized egg.

DESCRIPTION OF SYMBOLS 1 Lower plate 2 Chip 3 Substrate 4 Upper plate 5 Working electrode 6 First electrode pad 7 Second electrode pad 8 Third electrode pad 9, 10 Through-hole 11 Sealing material 12 Placement part 13 Opening 14, 54 Protrusion part 15 well 16 dimple 17 screw fastening part 18 through hole 19 biological material 20 reference electrode 21 measuring solution 30, 50 electrochemical measuring device 51 anisotropic conductive sheet 52 elastic body 53 thin wire

Claims (9)

A chip provided on the lower plate and the upper surface of the lower plate;
A working electrode provided on the top surface of the chip;
A first electrode pad provided on the top surface of the chip and electrically connected to the working electrode;
A substrate provided above the chip;
A second electrode pad provided on the lower surface of the substrate and electrically connected to the first electrode pad;
A third electrode pad provided on the substrate, electrically connected to the second electrode pad, and connected to an external terminal;
An upper plate provided on the upper surface of the substrate,
The upper plate and the substrate are electrochemical measurement devices having a through hole so as to expose the working electrode. A sealing material is provided between the chip and the upper plate,
The electrochemical measurement device according to claim 1, wherein the sealing material has an opening so as to expose the working electrode. The electrochemical measurement device according to claim 2, wherein the sealing material is an elastic body or an adhesive. The electrochemical measurement device according to claim 3, wherein the elastic body has a mirror surface on an upper surface and a lower surface. The electrochemical measurement device according to claim 1, wherein the substrate is one of a printed substrate, a flexible substrate, and a lead frame substrate. The electrochemical measurement device according to claim 1, wherein the third electrode pad is provided on the lower surface of the substrate. The electrochemical measurement device according to claim 1, wherein the first electrode pad and the second electrode pad are connected by a conductive paste. The upper plate, the lower plate, and the substrate have through holes for passing assembly alignment pins;
The electrochemical measurement device according to claim 1, further comprising a recess for aligning the chip with the lower plate. The electrochemical measurement device according to claim 2, wherein the sealing material is an anisotropic conductive sheet.

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