KR20030021612A - Manufactory Technology for Hetero-contact Thick film Sensor - Google Patents

Abstract

PURPOSE: A hetero contact thick film sensor, and a method for manufacturing the same are provided to improve the reliability, the durability, and the sensitivity of a gas sensor. CONSTITUTION: An Au paste is printed on an alumina substrate in a comb shape spreading from a center to both sides and is heat-processed to form electrodes. A paste is manufactured by mixing hetero powders sensing Co gas with an organic binder. The paste is printed on the electrodes by a screen printing and is heat-processed to form sensing films and overlap the sensing films in the center between the electrodes. Pt wires are connected to the alumina substrate to measure an electric character.

Description

Hetero-contact thick film sensor manufacturing technology {Manufactory Technology for Hetero-contact Thick film Sensor}

▶ Technical Field

Gas sensors require sensitivity, selectivity, stability, reliability, speed, reproducibility, economy and durability. In order to improve these characteristics, the gas sensor was manufactured in the form of a thick film heterojunction, which is a gas sensor manufacturing technology that improved the shape of the electrode and the sensing film. Through this manufacturing technology, it is possible to manufacture gas sensors with improved stability, reliability, economy, durability and sensitivity.

▶ Prior art in that field

① Composition and operation of the prior art

Conventional thick film electrode shape was designed to stagger the electrodes in the center (Fig. 3).

Conventional bulk heterojunction gas sensor manufacturing technology is generally manufactured in the following order.

1) Die pressing both powders to make pellets in bulk form.

2) After the heat treatment of the pellets, the electrode wires are bonded to both surfaces with a paste to sinter the electrodes (FIG. 4).

② Description of Problems of Prior Art

The sensor manufacturing method as described above has the following problems.

1) The conventional thick film electrode is a kind of sensing film, which is not suitable for heterojunction.

2)) The problem of poor bonding due to mechanical bonding of bulk type devices by die pressing.

2) Problems due to poor bonding between bulk elements and electrode wires.

3) Reliability and durability of devices due to various bonding failures.

4) Limitation of miniaturization of bulk device manufacturing.

5) Limitations of Mass Production due to Complex Processes.

In order to improve the problem of poor bonding due to mechanical bonding, which is the biggest disadvantage of the conventional bulk heterojunction sensor, reliability is produced by manufacturing a thick film heterojunction sensor that screen-prints a substrate by mixing a powder with an organic binder and forming a paste. The present invention provides a gas sensor device manufacturing technology having high sensitivity and durability.

An embodiment of the present invention is shown in FIGS. 1 and 2, and the existing embodiment is shown in FIGS. 3 and 4.

In the embodiment of the thick film electrode of FIG. 1, Au paste is printed on alumina (96%) substrate (5 mm × 5 mm) in a comb shape spreading from the center to both sides, and heat-treated at 800 ° C. for 10 minutes to form an electrode. I was.

In the embodiment of the heterojunction thick film sensor of FIG. 2, a heterogeneous powder capable of detecting CO gas is mixed on an electrode formed by FIG. 1 with an organic binder to form a paste, and then overlapped at the center of the electrode by screen printing. After printing with heat treatment to form a sensing film. A Pt wire was connected to the substrate to measure electrical properties.

In the conventional thick film electrode embodiment of FIG. 3, the electrodes are printed in a staggered form at the center.

In the conventional bulk heterojunction sensor of FIG. 4, the two powders are die pressed to form a bulk pellet and heat treated, and then the platinum wires are bonded on both sides with a paste to sinter the electrode. Was formed.

5 shows the technical characteristics of the new technology compared with the prior art.

1) To produce thick film specimen of heterojunction sensor, electrode printing is spread out from center to both sides. Unlike the conventional electrode type used in the conventional one sensor, invented the electrode form for heterojunction (Fig. 1).

2) The powder is mixed with an organic binder to make a paste and printed so that the two sensing layers overlap at the center between the electrodes. Invented a gas sensor element thinner and smaller than the existing bulk form, excellent bonding and high sensitivity (Fig. 2).

Compared with the prior art, the sensor element has been miniaturized, mass production is possible, and the heterogeneous bonding is excellent, thus producing a gas sensor having improved stability, reliability, economy, durability and sensitivity. The results are shown as percentages in FIG. 5 compared to the prior art.

Claims (2)

In the electrode printing of the substrate, a comb-like electrode printing technique spreading on both sides for heterojunction (FIG. 1). A manufacturing method of a thick film sensor device of a heterojunction in which two sensing films overlap at a center part between electrodes (FIG. 2).