EP0202705A1 — Patterned polyimide film, a photosensitive polyam…

Claim 1

Independent Claim 113 words

A method of forming on a substrate a patterned polyimide film which is provided with an electrically conductive layer at the upper surface facing away from the substrate, characterized in that the substrate is provided with a layer of a photosensitive polyamide acid derivative onto which a layer of positive photoresist is applied, after which the assembly is exposed patternwise, the photoresist layer is developed, an electrically conductive layer is applied to the photoresist layer which is then removed by means of a lift-off process, the unexposed parts of the layer of polyamide acid derivative are removed and the remaining exposed parts are subjected to a heat treatment and imidised to form polyimide.

Claim 2

Independent Claim 113 words

A method of forming on a substrate a patterned polyimide film which is provided with an electrically conductive layer at the upper surface facing away from the substrate, characterized in that the substrate is provided with a layer of a photosensitive polyamide acid derivative onto which a layer of positive photoresist is applied, after which the assembly is exposed patternwise, the photoresist layer is developed, an electrically conductive layer is applied to the photoresist layer which is then removed by means of a lift-off process, the unexposed parts of the layer of polyamide acid derivative are removed and the remaining exposed parts are subjected to a heat treatment and imidised to form polyimide.

Claim 3

Dependent Claim 103 words

A method as claimed in Claim 1, characterized in that a positive photoresist is used whose absorption wavelength differs from that of the photosensitive polyamide acid derivative, the exposure of the assembly in accordance with a certain pattern being carried out in two successive steps, the first step consisting in exposing the assembly in accordance with a certain pattern to light whose emission wavelength corresponds to the absorption wavelength of the photoresist, and the second step consisting in exposing the assembly in accordance with a certain pattern to light whose emission wavelength corresponds to the absorption wavelength of the photosensitive polyamide acid derivative.

Claim 4

Dependent Claim 41 words

A method as claimed in Claim 2, characterized in that a positive photoresist is used having an absorption wavelength situated in the near U V spectrum and a polyamide acid derivative having an absorption wavelength situated in the U V spectrum.

Claim 5

Dependent Claim 20 words

A method as claimed in Claim 3, characterized in that a layer of polymethylmethacrylate is used as a positive photoresist.

Claim 6

Dependent Claim 126 words

A method as claimed in Claim 3 or 4, characterized in that a photosensitive polyamide acid derivative is used which is obtained by making polyamide acid react with one or more compounds of formula 1 of the formula sheet, in which R1 is equal or unequel to R 2 and both represent a lower alkylgroup having 1-4 carbon atoms or a hydrogen atom, R is an alkylene group having 1-5 carbon atoms, X is an oxygen atom or the group - N(R 3 ) - , in which R 3 is a hydrogen atom or a lower alkyl group having 1-4 carbon atoms, and m has the value 0 or 1, on the condition that in at least one compound the value of m is 1.

Claim 7

Dependent Claim 103 words

A method as claimed in Claim 5, characterized in that the polyamide acid derivative used is obtained by making polyamide acid react with one or more compounds in accordance with formula 2, in which R 4 is a hydrogen atom, a methyl group or an ethyl group, Y is an oxygen atom or the group - N(R 5 ) - , in which R 5 is a hydrogen atom or a methyl group, p has the value 0 or 1, and m has the value 0 or 1, on the condition that at least in one compound the value of m is 1.

Claim 8

Dependent Claim 81 words

A method as claimed in Claim 5, characterized in that a polyamide acid derivative is used which is obtained by making polyamide acid react with a mixture containing 10-90 mol.% of a compound of formula 1 in which m = 1 and R 1 , R 2 R and X have the above-stated meaning, and 10-90 mol.% of a compound of formular 1 in which m = 0 and R 1 , R 2 R and X have the above-stated meaning.

Claim 9

Dependent Claim 45 words

A method as claimed in Claim 7, characterized in that a polyamide acid derivative is used which is obtained by making polyamide acid react with a mixture containing 10-90 mol.% of a compound of formula 3 and 10-90 mol.% of a compund of formula 4.

Claim 10

Dependent Claim 95 words

A photosensitive polyamide acid derivative which is obtained by making polyamide acid react with one or more compounds in accordance with formula 7, in which R is equal or unequal to R 2 and both are a lower alkyl group having 1-4 carbon atoms or one hydrogen atom, R is an alkylene group having 1-5 carbon atoms, R 3 is a lower alkyl group having 1-4 carbon atoms or a hydrogen atom, and m has the value 0 or 1 on the condition that in at least one compound the value of m is 1.

Claim 11

Dependent Claim 95 words

A photosensitive polyamide acid derivative which is obtained by making polyamide acid react with one or more compounds in accordance with formula 7, in which R is equal or unequal to R 2 and both are a lower alkyl group having 1-4 carbon atoms or one hydrogen atom, R is an alkylene group having 1-5 carbon atoms, R 3 is a lower alkyl group having 1-4 carbon atoms or a hydrogen atom, and m has the value 0 or 1 on the condition that in at least one compound the value of m is 1.

Claim 12

Dependent Claim 87 words

A photosensitive polyamide acid derivative as claimed in Claim 9, characterized in that the derivative is obtained by making polyamide acid react with one or more compounds in accordance with formula 9 in which R 4 is a hydrogen atom, a methyl group or an ethyl group, R 5 is a hydrogen atom or a methyl group, p has the value 0 or 1, and m has the value 0 or 1, on the condition that in at least one compound the value of m is 1.

Claim 13

Dependent Claim 76 words

A photosensitive polyamide acid derivative as claimed in Claim 9, which is obtained by making polyamide acid react with a mixture containing 10-90 mol.% of a compound of formula 1 in which m = 1 and R 1 , R 2 , R and X have the above-stated meaning and 10-90 mol.% of a compound of formula in which m = 0 and R 1 , R 2 , R and X have the above-stated meaning.

Claim 14

Dependent Claim 48 words

A photosensitive polyamide acid derivative as claimed in Claim 11, which is obtained by making polyamide acid react with a mixture containing 10-90 mol.% of a compound of formula 3 and 10-90 mol.% of a compound of formula 3 and 10-90 mol.% of a compound of formula 4.

Claim 15

Dependent Claim 75 words

An electrophoretic image-display cell comprising two parallel cell walls at least one of which is transparent, one or more electrodes which are provided on the inside surface of each cell wall as well as a net-shaped electrode which is arranged between both cell walls, which net-shaped electrode runs parallel to the said cell walls and is supported by a dielectric layer having a network structure, characterized in that the dielectric layer is made of polyimide.

Claim 16

Dependent Claim 75 words

An electrophoretic image-display cell comprising two parallel cell walls at least one of which is transparent, one or more electrodes which are provided on the inside surface of each cell wall as well as a net-shaped electrode which is arranged between both cell walls, which net-shaped electrode runs parallel to the said cell walls and is supported by a dielectric layer having a network structure, characterized in that the dielectric layer is made of polyimide.

Claim 17

Dependent Claim 39 words

An electrophoretic image-display cell, characterized in that the polyimide layer which is provided with an electrode is applied in accordance with a certain pattern by making use of the method in accordance with any one of the Claim 1-8.

Patterned polyimide film, a photosensitive polyamide acid derivative and an electrophoretic image-display cell

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