JPH0750709Y2 - Ion sensor and sensor plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an ion sensor, a sensor plate of its component, and a structure of a sample liquid supply unit.

[Conventional technology]

The ion sensor is for measuring the ion concentration in the sample liquid, and is a so-called ion-sensitive field-effect type in which an ion-sensitive film is formed on the gate electrode of a field-effect transistor (FET) formed in a semiconductor. Transistor (IS
FET) is called. This ISFET utilizes the fact that when a sample liquid is brought into contact with the ion-sensitive film, the conductivity near the semiconductor surface changes in response to the change in the electric field generated at the interface between the ion-sensitive film and the solution. It can be detected.

This ISFET is not on the semiconductor substrate on which the FET is formed,
A separate gate electrode is provided on another insulating substrate, an ion-sensitive film is provided on it, and a separate reference electrode is provided opposite to it to form an independent component, which is used by connecting it to an FET. Has been.

The ion sensitive part of such a separated gate type ISFET ion sensor is a so-called printed wiring board in which a copper foil with a thickness of 3.5 μm is adhered on an insulating substrate, for example, a glass / epoxy resin substrate, a photolithographic method, etc. To a copper conductive pattern of a predetermined shape by electroplating, and then electroplating using a commercially available silver plating bath for thickening, etc. to form a silver layer on the surface to a thickness of several μm to 20 μm. A silver chloride layer having a thickness of several μm is formed on the surface of the silver layer by immersing in a sodium chloride solution and subjecting it to electrolytic conversion treatment. Then, after forming a bank with an insulating resin, for example, an epoxy resin, so as to surround an electrode having a laminated structure of a silver layer and a silver chloride layer on the surface layer portion, a macrocyclic compound called an ionophore and an ion exchange resin are included. An ion sensitive film is formed on an electrode, and this structure was proposed in the previous application.

[Problems to be solved by the device]

However, the bank formed of epoxy resin on the surface layer of the substrate is formed by applying a curable epoxy resin liquid onto the substrate and curing it, so the curing time is long and the curing agent Depending on the type, the work efficiency is poor because it must be cured in a high temperature atmosphere. Further, in the method of applying the resin liquid, if an attempt is made to increase the height of the levee body, the dimensional accuracy of the levee body deteriorates due to the sagging of the edge portion, and the amount of the sample liquid retained cannot be made constant.

For these reasons, the levee body must be lowered, but if the levee body is low, the amount of the sample liquid dropped inside should be reduced so as not to overflow. If the amount of the sample liquid is small, the liquid may not be uniformly distributed in the levee due to the surface tension, and the sample may not come into contact with the ion-sensitive membrane of the ion-sensitive section or the reference electrode, resulting in large variations in the measured values.

An object of the present invention is to provide an ion sensor in which a bank surrounding the ion sensitive section can be easily provided and the height of the bank can be freely controlled, and a template for the ion sensor.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the present invention provides an ion sensor in which a field effect type semiconductor can detect the sensitive value of a sample liquid by an ion sensitive section provided on a substrate, and a bank surrounding the ion sensitive section. A body is provided on a substrate to form a window portion for supplying a sample liquid, the bank is composed of a laminated body of a molded body and an adhesive, and the adhesive is adhered to the substrate by the adhesive. An ion sensor is provided.

Further, a separation gate electrode to be used by connecting to the gate electrode of the field effect semiconductor and a separation reference electrode are provided on an insulating substrate which is separate from the field effect semiconductor substrate, and the separation gate electrode is ion-sensitive. A membrane is provided, and a levee body surrounding the separation gate electrode and the comparison electrode provided with the ion sensitive membrane is provided on the substrate to form a window portion for supplying the sample liquid, and the levee body is formed into a molded body and an adhesive body. The present invention provides a sensor plate comprising a laminated body of 1. and the adhesive body adhered to the substrate by the adhesion.

Next, the present invention will be described in detail.

In the present invention, the adhesive constituting the bank for holding the sample liquid is acrylic ester, polyvinyl ether, polyisobutylene, styrene-butadiene rubber, butyl rubber, chloroprene rubber, vinyl chloride-vinyl acetate copolymer resin, chlorinated rubber. It is also preferable to form a sheet from a material such as polyvinyl butyral and punch it out to form the same shape as the below-mentioned shaped body, and to stick both together, because high dimensional accuracy can be obtained, but both sides of the base material It is also used as a double-sided pressure-sensitive adhesive tape obtained by laminating sheets molded from the above materials, or applying a solution of the above materials. In this case, examples of the material of the base material include acrylic, polyurethane, polyether, polyvinyl chloride, polyethylene, polyester, synthetic rubber, paper, cloth and cellophane, and of these, foams are also preferably used. Since the foamed material has excellent flexibility, there is an advantage that the conformability to the surface shape of the substrate is good and the sealing property is higher. The thickness of the adhesive body is preferably 20 μm to 1 m
m.

It is to be noted that a molded body to which a pressure-sensitive adhesive is applied as a pressure-sensitive adhesive body is also used.

Further, the bank body of the present invention uses a molded body, but as this material, plastics such as polypropylene, polyethylene, polyvinyl chloride, and rubber such as butyl rubber and nitrile butadiene rubber can be used, and a material that is chemically stable is used. It is preferable to use selectively. To obtain a molded product from these materials, a molding means such as injection molding or a sheet body is punched.

It is also possible to use a laminate in which the molded body and the adhesive body are alternately laminated in a plurality of stages.

The above-mentioned molded body and the pressure-sensitive adhesive body can be laminated by sticking together, and in order to bond this laminated body to the substrate, the pressure-sensitive adhesive body side is bonded to the substrate and pressure is applied to the joint portion by means of a press or a roller.

Although the bank is provided on the substrate as described above, this substrate may be one in which the FET, the gate electrode, and the comparison electrode are integrally formed, and the gate electrode is extended to compare the separated gate electrode to another substrate. A substrate different from the FET formed together with the electrodes may be used.

Function A levee body can be formed by simply adhering a laminate of a molded body and an adhesive body to a substrate, and the molded body and the adhesive body can be easily obtained by, for example, punching. You can Also, the height of the bank can be easily controlled by adjusting the thickness of the molded body or the adhesive body.

Embodiment Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The copper foil adhered to the paper polyester substrate 1 was polished with diamond slurry to give a mirror finish, and copper electrodes 1a and 1b having a predetermined shape were formed by a photolithographic method.

Next, using a commercially available cyan-based silver strike plating bath containing 1 g / l of silver and a constant current power source, the cathode current density was 0.5 A / dm ²
The above substrate was immersed in a bath for 5 seconds, taken out, and washed with water. Then, it was immersed in a commercially available cyan-based electrolytic bright plating bath containing 20 g / l of silver while maintaining the temperature at 50 ° C, and electrolytically plated at a current density of 12 A / dm ² for 1 minute and 30 seconds, and a silver layer 2 a with a thickness of 15 μm was formed. , 2b was formed.

Then, in 0.1N (N) hydrochloric acid (HCl), the substrate was used as an anode, a platinum-plated titanium mesh was used as a cathode, and electrolysis was performed at an anode current density (0.2 A / dm ² ) for 2 minutes and 40 seconds. Silver chloride layers 3a and 3b were formed on the surfaces of the silver layers 2a and 2b.

The silver chloride layer 3a is coated with an ion-sensitive film 4 containing a vinyl chloride-vinyl acetate-based copolymer as a main component, and the electrode on which the ion-sensitive film is formed and the silver chloride electrode 3b are surrounded,
The bank body 5 is formed. That is, as shown in FIG. 3, this bank has a double-sided adhesive tape 5b (thickness 0.4 m) formed on a molded body 5a obtained by punching out a polypropylene sheet (thickness 0.5 mm) in a rectangular frame shape.
m, Scotch VHB (manufactured by Sumitomo 3M Ltd.), then the other surface of this adhesive tape is bonded to the substrate surface and the silver chloride layers 3a and 3b, and pressed at a pressure of 5 Kg / cm ² for 3 seconds. did. In this way, the sensor plate is completed.

In this sensor plate, the electrode 3a coated with the ion-sensitive membrane is used as a separation gate electrode, the silver chloride electrode 3b is used as a reference electrode, and each is connected to a FET (not shown). By dipping
The contained ion concentration can be measured as the output value of the ion sensor.

Comparative Example In the above example, instead of the cut-off body made of the punched polypropylene sheet and the pressure-sensitive adhesive layer, epoxy resin was screen-printed and heated at 100 ° C. for 2 hours to form a cut-off wall (height 0.06 mm). A sensor plate was prepared in the same manner except that the above was performed.

The following table shows the time required to form the bank body and the volume ratio inside the bank body (1 in the comparative example) for the sensor plates prepared in the above-mentioned Examples and Comparative Examples.

From the above results, it can be seen that the bank of the example has a significantly shorter formation time and a significantly larger amount of the sample retained than the bank of the comparative example.

[Effect of device]

According to the present invention, since the levee body is formed by adhering the laminated body of the molded body and the adhesive body to the substrate, the forming time is extremely short, its working efficiency is good, and its height can be easily controlled. The amount of sample liquid can be optimized.

[Brief description of drawings]

FIG. 1 is a plan view of a sensor plate according to an embodiment of the present invention,
Fig. 2 is the II-II sectional view, and Fig. 3 is the sectional view of the dam body. In the figure, 1 is a substrate, 2a and 2b are silver layers, 3a and 3b are silver chloride layers, 4
Is an ion sensitive membrane, 5 is a bank, 5a is a molded body, and 5b is an adhesive body.

Claims (2)

[Scope of utility model registration request] 1. An ion sensor in which a field effect type semiconductor can detect a sensitive value of a sample liquid by an ion sensitive part provided on a substrate, wherein a bank surrounding the ion sensitive part is provided on the substrate. An ion sensor characterized in that a window portion for supplying a sample liquid is formed, the bank is composed of a laminate of a molded body and an adhesive, and the adhesive is adhered to the substrate by the adhesive. 2. A separation gate electrode used for connecting to a gate electrode of the field effect semiconductor and a separation comparison electrode are provided on an insulating substrate which is separate from the field effect semiconductor substrate, and the separation gate electrode is provided. An ion-sensitive film is provided on the substrate, a bank surrounding the separation gate electrode provided with the ion-sensitive film and the reference electrode is provided on the substrate to form a window for supplying the sample liquid, and the bank is molded. And a pressure-sensitive adhesive body, which is adhered to the substrate by the pressure-sensitive adhesive body.