Patent Yard Sign in
Expired Canadian patentCanada

Wafer holding apparatus for holding a wafer

CA 2109240 C · Owner: Ueda, Minoru · Inventors: Ueda, Minoru

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

Open the CIPO record

Abstract From the Canadian patent

A wafer holding apparatus for holding a wafer stationary includes a main body and a plate member detachably placed on the main body. The main body includes a cavity having an open end at the upper surface of the main body and includes a passageway extending from the cavity to communicate the cavity with a vacuum pump. The plate member is placed on the main body to plug the open end of the cavity and supports on its upper surface a wafer to be processed. The plate member has a number of through bores arranged in a predetermined arrangement matched for the arrangement of micromachined sections of the wafer where micromachines or integrated circuits are to be formed. Before processing of the …

Read the whole patent

Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed October 26, 1993 and granted November 18, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 26, 2013.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 26, 2015.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 26, 1993
GrantedNovember 18, 1997
Term endedOctober 26, 2013
Patent numberCA 2109240 C
Classification (IPC)H01L21/68 +2 more

Timeline

Timeline From CIPO dates

1994199619982000200220042006200820102012Application filedOct 26, 1993Patent grantedNov 18, 1997Term endedOct 26, 2013

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.