Electrolyte composition for screen printing and miniaturized oxygen electrode and production process thereof

• US 5,478,460 A
• Filed: 11/03/1993
• Issued: 12/26/1995
• Est. Priority Date: 03/20/1991
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Suzuki, Hiroaki, Sugama, Akio, Kojima, Naomi
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/145,277
• Time in Patent Office: 783 Days
• Field of Search: 204/403, 204/415, 204/153.17, 204/283, 204/418, 204/419, 204/431, 204/414, 427/115, 252/500, 252/62.2
• US Class Current: 438/49
• CPC Class Codes: G01N 27/404 Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid , e.g. Clark-type oxygen sensors

Abstract

An electrolyte composition for screen printing, comprising: an organic solvent; an inorganic salt in the form of a fine powder able to pass through a screen printing mesh, the salt powder being dispersed in the organic solvent; and polyvinyl pyrrolidone dissolved in the organic solvent. A miniaturized oxygen electrode having an oxygen sensing site filled with the electrolyte composition. A process for producing a miniaturized oxygen electrode, including a step of patterning or selectively removing an oxygen gas-permeable membrane at a pad region by removing or peeling off an underlying cover film formed thereunder.

Claims

1. A process of producing a miniaturized oxygen electrode, comprising the steps of:

preparing an electrically insulating substrate;

forming an electrolyte-containing material on said substrate;

forming on said substrate a set of component electrodes in contact with said electrolyte-containing material; and

forming an oxygen gas-permeable membrane covering said electrolyte-containing material;

said forming of said electrolyte-containing material being carried out by screen-printing on said substrate an electrolyte composition comprising;

an organic solvent;

an inorganic salt in the form of a fine powder able to pass through a screen printing mesh prepared by pulverizing potassium chloride or sodium chloride, said salt powder being dispersed in said organic solvent; and

polyvinyl pyrrolidone dissolved in said organic solvent.

2. A process according to claim 1, wherein said electrolyte composition is prepared by pulverizing a buffering agent together with said inorganic salt.

3. A process for producing a miniaturized oxygen electrode, comprising the steps of:

preparing an electrically insulating substrate;

forming an electrolyte-containing material on said substrate;

forming on said substrate a set of component electrodes each having an end in contact with said electrolyte-containing material and an end for external electrical connection; and

forming a removable cover film on said substrate in a region to be exposed in the following removing step, said region containing said component electrode end for external electrical connection;

forming an oxygen gas-permeable membrane covering the substrate surface including the region of said removable cover film; and

removing said oxygen gas-permeable membrane by peeling said removable cover film away from said substrate surface, to expose said to-be-exposed region of said substrate, to thereby shape said oxygen gas-permeable membrane to a set pattern.

4. A process according to claim 3, comprising the steps of:

screen-printing a thermosetting resin onto said to-be-exposed region of said substrate;

heating said resin to cure the resin to form a resin film as said removable cover film;

forming said oxygen gas-permeable membrane covering the substrate surface including the region of said resin film;

peeling said resin film to expose said to-be-exposed region, to thereby shape said oxygen gas-permeable membrane to a set pattern.