Sheet-like switch with nonoverlapping conductive patterns

• US 5,892,191 A
• Filed: 09/24/1996
• Issued: 04/06/1999
• Est. Priority Date: 09/29/1995
• Status: Expired due to Term

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Yamada, Naoki, Hagiya, Ryuichi, Takemori, Satoru
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US08/717,654
• Time in Patent Office: 924 Days
• Field of Search: 200/5 A, 200/5 R, 200/512, 200/513, 200/514, 200/515, 200/516, 200/517, 338/279
• US Class Current: 200/5.00A
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 13/703 characterised by spacers between contact carrying layers
• CPC Class Codes: H01H 2207/046 Non overlapping lower and upper conductors
• CPC Class Codes: H01H 2211/006 Individual areas
• CPC Class Codes: H01H 2231/05 Card, e.g. credit card

Abstract

A sheet-like switch is disclosed in which the migration of silver can be prevented without requiring the provision of an overcoat. An upper electrode sheet is formed by disposing upper contacts and upper conductive patterns electrically connected to each other on an insulating sheet. A lower electrode sheet is formed by disposing lower contacts and lower conductive patterns electrically connected to each other on an insulating sheet. The upper and lower electrode sheets are stacked on each other across a spacer film provided with a hole. The upper and lower contacts are placed to opposedly face each other within the hole, and the upper and lower conductive patterns located within the hole are extended to the exterior in different directions, so that the upper and lower conductive patterns positioned on the peripheral portion of the hole can be prevented from overlapping each other across the spacer film in the upward and downward direction. Further, the length along the peripheral portion of the hole defined between the upper and lower conductive patterns positioned on the peripheral portion may preferably be 0.5 mm or greater.

Claims

1. A sheet-like switch comprising:

an upper electrode sheet having a plurality of upper contacts and plurality of upper conductive patterns electrically connected to said upper contacts;

a lower electrode sheet having a plurality of lower contacts and a plurality of lower conductive patterns electrically connected to said lower contacts; and

a spacer film having a plurality of holes, said spacer film being located between said upper and lower electrode sheets, each of said plurality of holes having a peripheral edge,

wherein each of said upper contacts and an associated one of said lower contacts are located to opposedly face each other within an associated hole of said spacer film, and

wherein all of said upper conductive patterns extend from respective upper contacts in different directions relative to associated lower conductive patterns respectively extending from associated lower contacts such that the upper conductive pattern of each associated pair of said upper and lower conductive patterns contacts a first portion of the peripheral edge of said associated hole which is displaced along said peripheral edge from a second portion contacted by the lower conductive pattern of said associated pair of upper and lower contact patterns.

2. A sheet-like switch according to claim 1, wherein a length along the peripheral portion of said hole defined between said upper and lower conductive patterns positioned on the peripheral portion is 0.5 mm or greater.

3. A sheet-like switch according to claim 1, wherein a spacer is disposed around at least one of said upper contact and said lower contact in the vicinity of the hole of said spacer film.

4. A sheet-like switch according to claim 2, wherein a spacer is disposed around at least one of said upper contact and said lower contact and in the vicinity of the hole of said spacer film.

5. A sheet-like switch according to claim 1, wherein neither of said upper and lower conductive patterns are covered by an overcoat layer.