Title of Invention

ELECTRICALLY CONDUCTING COATED KAPTON FILM

Abstract

A method of manufacture of electrically conducting cated kapton film comprising the steps of ecacuating a chamber to 4.0-5.2*10^-5 milli Bar vacuum pressure; letting in oxygen into the chamber so that the chamber pressure further rises to 0.0009-0.001 milli Bar; letting in argon into the chamber so tht the chamber pressure further rises to 0.015-0.02 milli Bar;placing the film to be coatred on a first supp0ort within the chamber;placing, prior to evacuation,the targer material consisting of tin doped indium(10%tin+90% indium by weight)on a second suppot at a distance of 5.0-9.0cm from the first support;connecting a dc magnetron, to the target(-ve lead to the target and =ve grounded) so as to cause sputtering and thus deposit the target material on the film to provide a coating thereon of the target material on the film to provide a coating thereon of the targer material, which is electrically conducting.

Full Text

This invention relates to electrically conducting coated kapton film. Kapton is a trade mark of Dupont, USA, and pertains to a polyimide film. It possesses a unique combination of properties that makes it ideal for a variety of applications in many different industries, such as, electrical and electronic insulation applications. One of the very important applications of these films is their use in satellites. For this specific application, the films are to be electrically conducting on the outer surface for protecting against static discharge. These surface coatings have also to withstand harsh environments like extremely low temperature and exposure to hard radiations. The method, according to this invention, comprises the -5 steps of evacuating a chamber to 4.0 - 5.2 x 10 milli Bar vacuum pressure; letting in oxygen into the chamber so that the chamber pressure rises to 0.0009 - 0.001 milli Bar; letting in argon into the chamber so that the chamber pressure further rises to 0.015 - 0.02 milli Bar; placing the film to be coated on a first support within the chamber; placing, prior to evacuation, the target material consisting of tin doped indium (10% tin + 90% indium by weight) on a second support at a distance of 5.0 - 9.0 cm from the first support; connecting a dc magnetron, to the target (-ve lead to the target and +velead grounded) so as to cause sputtering and thus deposit the target material on the film to provide a coating thereon of the target material, which is electrically conducting. This invention will now be described with reference to the accompanying drawings, which illustrate in the single Figure therein an apparatus for carrying out the metliod of manufacture of the film proposed herein. -S . The chamber C is evacuated to 4.0 - 5.2 x 10 milV bar vacuum pressure, in order to clean the chamber. Thereafter oxygen is let into the chamber C until the chamber pressure rises to 0.0009 - 0.001 milhBar. Next, argon is let into the chamber so that the chamber pressure further rises to 0.015 - 0.02 millJBar. f Thereafter the film^to be coated ( 13 cm x 13 cm) is placed on a first support S1 within the chamber C. The target material 7 which is an alloy of tin doped indium (10% tin + 90% indium by weight) is placed, prior to evacuation, on a second support S2 at a distance of 5.0 -9.0 cm from the first support. A dc magnetron power supply M is connected to the target (-ve lead to the target and +ve lead grounded) so as to cause sputtering resulting in the deposition of a portion of the target material on the film to provide a coating thereon of the target material, which is electrically conducting. The time of sputtering is about 25 - 45 minutes and this period determines the thickness and quality of the coating. The plasma striking voltage is in the range of 490 - 380 Volts for magnetron power of 25 - 40 watts. The terms and expressions in this specification are of description and not of limitation, as these do not exclude any equivalents of the features illustrated and described, having regard to the scope and ambit of this invention. 4 A method of manufacture of electrically conducting coated kapton film substantially as herein described and illustrated with reference to the accompanying drawings. 5. Electrically conducting coated kapton film whenever manufactured by a method as claimed in any one of the preceding Claims. Dated this the 17* day of March 2003 We Claim: 1. A method of manufacture of electrically conducting coated kapton film comprising the steps of -5 evacuating a chamber to 4.0 - 5.2 x 10 milli Bar vacuum pressure; letting in oxygen into the chamber so that the chamber pressure rises to 0.0009 - 0.001 milli Bar; letting in argon into the chamber so that the chamber pressure further rises to 0.015 - 0.02 milli Bar; placing the film to be coated on a first support within the chamber; placing, prior to evacuation, the target material consisting of tin doped indium (10% tin + 90% indium by weight) on a second support at a distance of 5.0 - 9.0 cm fi^om the first support; connecting a dc magnetron, to the target (-ve lead to the target and +ve grounded) so as to cause sputtering and thus deposit the target material on the film to provide a coating thereon of the target material, which is electrically conducting. 2. A method as claimed in Claim 1 wherein the sputtering time is 25 - 45 minutes. 3. A method as claimed in Claim 1 or Claim 2 wherein the plasma striking voltage is in the range of 490 - 380 Volts for magnetron power of 25 - 40 watts. 4 A method of manufacture of electrically conducting coated kapton film substantially as herein described and illustrated with reference to the accompanying drawings. 5. Electrically conducting coated kapton film whenever manufactured by a method as claimed in any one of the preceding Claims.

Documents:

223-che-2003-claims duplicate.pdf

223-che-2003-claims original.pdf

223-che-2003-correspondnece-others.pdf

223-che-2003-correspondnece-po.pdf

223-che-2003-description(complete) duplicate.pdf

223-che-2003-description(complete) original.pdf

223-che-2003-drawings.pdf

223-che-2003-form 1.pdf

223-che-2003-form 19.pdf

223-che-2003-form 26.pdf