JPS6355451A - Biosensor - Google Patents

Abstract

PURPOSE:To prevent the disconnection of a wire and the generation of a leak by sealing a wire bonding junction by the sealing agent of a rubber compound. CONSTITUTION:To the upper face part of the tip of a glass epoxy substrate 1, a sensor chip 2 is stuck 3 in a state that the tip of chip is protruded from the substrate 1. Also, on the upper face of the chip 2, an ion sensitive FET4 is patterned, and on a part of this FET4, the fixed film 5 of enzyme is provided. Moreover, the end part of a lead wire 6 of the FET4 and the end part of a lead wire 7 for a detector provided on the upper face of the substrate 1 are connected by wire bonding 8. On the other hand, other part than the tip part of the substrate 1 and the fixed film 5 of the chip 2, and the bonding 8 are sealed in a muffler shape by the sealing agent of a rubber compound. Accordingly, at the time of curing, this sensor does not contract, and even after curing, it has elasticity, therefore, the disconnection of a wire is hardly occurred, and the leak can be prevented.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a biosensor.

(Prior technology) Conventionally, sensor chips in which an enzyme immobilization film is provided on the surface of an ion-sensitive field effect transistor have been made by bonding the sensor chip onto a flat glass epoxy substrate, which is difficult to handle in chip form. Ta. The sensor transistor lead wires and the glass epoxy board lead wires were connected by wire bonding, and the wire bonding and wire bonding joints were padded with adhesive to prevent leakage.

(Problems to be Solved by the Invention) In the conventional biosensor mentioned above, the wire bonding and the wire bonding joint are bonded with an adhesive (epoxy type), but the wire breaks due to shrinkage during bonding. There was often something to do.

Furthermore, since only the wire bonding joints were bonded, there was a drawback that leaks could occur from the boundary between the glass epoxy substrate and the adhesive.

An object of the present invention is to eliminate such drawbacks and provide a biosensor that is free from wire breaks and leaks.

(Means for Solving the Problems) The present invention provides a biosensor in which a sensor chip in which an enzyme immobilization film is provided on the surface of an ion-sensitive field effect transistor is adhered to a glass epoxy substrate.
The sensor chip has an enzyme-immobilized film part protruding from the glass epoxy substrate and is bonded thereto, and the lead wires of the sensor chip and the lead wires of the glass epoxy board are wire-bonded. is characterized by being sealed with a rubber sealant.

(Function) According to the biosensor of the present invention, since the wire bonding joint is sealed with a rubber-based sealant, there is no shrinkage during curing, and there is elasticity even after curing, so the wire cannot be disconnected. No. Furthermore, the chip and glass epoxy substrate, including the wire bonding joints, are sealed with a rubber sealant in a wrap-around manner, so there is no leakage and the adhesive strength is excellent.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of a biosensor that is an embodiment of the present invention, and FIG. 2 is a side sectional view showing the sealed state of FIG. 1.

In this embodiment, a sensor chip 2 is bonded to two sides of a glass epoxy substrate 1 with an adhesive 3, with the tip thereof protruding from the glass epoxy substrate 1. An ion-sensitive field effect transistor 4 is patterned on the upper surface of the sensor chip 2, and an enzyme immobilization film 5 is formed on a part of the ion-sensitive field effect transistor 4. The lead wire end 6 of this ion-sensitive field effect transistor 4 and the end of a lead wire 7 for a detector provided on the negative surface of the glass epoxy substrate 1 are connected by wire bonding 8. Glass epoxy substrate 1
The tip of the sensor chip 2, the portion of the sensor chip 2 other than the enzyme immobilization film 5, and the wire bonding 8 are sealed with a rubber sealant 9 in a wrap-around shape.

Next, the assembly method of this embodiment will be explained.

A small amount of fast-curing adhesive 3 (hardening time: about 10 minutes) is applied to the upper end of the glass epoxy substrate 1, and the sensor chip 2 is placed on the upper surface and lightly pressed to stabilize it. At this time, the sensor chip 2 is fixed so that the enzyme immobilization film 5 provided on a part of the ion-sensitive field effect transistor 4 on the upper surface protrudes from the upper end of the glass epoxy substrate 1. Once the adhesive 3 is cured, wire bonding 8 is performed to connect the lead wire end 6 of the ion-sensitive field effect transistor 4 and the end of the detector lead wire 7 provided on one surface of the glass epoxy substrate 1. Connect with. Next, seal the tip of the glass epoxy substrate 1 and the wire bonding 8 part with a rubber sealant 9 in a wrap-around shape so that it does not get on the enzyme immobilization film 5 provided on the top surface of the sensor chip 2. do. The surface of this rubber sealant hardens in just a few minutes, making it convenient to handle.

(Effects of the invention) As explained above, since the wire bonding joint is sealed with a rubber-based sealant, there is no shrinkage during curing, and the wire remains elastic even after curing, so there is no possibility of wire breakage. . Furthermore, since the chip and glass epoxy substrate, including the wire bonding joints, are sealed with a rubber sealant in a wrap-around manner, there is no leakage and the adhesive strength is excellent.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a biosensor which is an embodiment of the present invention, and FIG. 2 is a side sectional view showing the sealed state of FIG. 1. 1...Glass epoxy substrate, 2...Sensor chip,
3... Adhesive, 4... Ion-sensitive field effect transistor, 5... Enzyme immobilization membrane, 6... Lead wire, 7... Lead wire for detector, 8... wire bond 61

Claims (1)

[Claims] In a biosensor in which a sensor chip in which an enzyme immobilization film is provided on the surface of an ion-sensitive field effect transistor is formed on a glass epoxy substrate, the sensor chip is formed with an enzyme immobilization film portion protruding from the glass epoxy substrate. , a biosensor characterized in that the lead wires of the sensor chip and the lead wires of the glass epoxy substrate are wire-bonded, and the area other than the enzyme-immobilized film portion on the top surface of the sensor chip is sealed with a rubber-based sealant. .