Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Radiation sensitive composition or product or process of making
Reexamination Certificate
1999-03-26
2002-04-02
Baxter, Janet (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Radiation sensitive composition or product or process of making
C430S270100, C430S927000, C528S038000, C528S353000
Reexamination Certificate
active
06365324
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a photosensitive composition, and more particularly to a photosensitive composition capable of giving a negative type polyimide pattern upon development with an aqueous alkaline solution.
2. Description of Related Art
So far used photosensitive resins are typically polyester acrylate, epoxy acrylate, etc. To obtain a desired pattern upon exposure of these photosensitive resins to light, an organic solvent is used as a developing agent. Such organic solvent developing type, photosensitive resins have such a serious problem as an adverse effect on the environments in addition to safety or sanitary problem during working due to the use of the organic solvent.
In place of the organic solvent developing type, photosensitive resins having such problems, alkali-developable photosensitive resins based on novolak resins, polyvinylphenol, etc. have been proposed and almost all of them have been utilized as positive type thin films having a thickness of a several &mgr;m, but these positive type thin films have not always satisfied the heat resistance, preservation stability, pattern embedability, etc. required by FPC (flexible printed substrate) applications.
Furthermore, polyimide resins themselves are insoluble in an organic solvent and therefore have so far relied on such a method of once converting them to organic solvent-soluble polyamic acids, followed by their polyimidization. However, some of polyimide resins themselves are soluble in an organic solvent. For example, polyimide resins disclosed in JP-A-57-131227 and polyamide-imide resins disclosed in JP-A-59-145216 are said to be soluble in an organic solvent and photosensitive. However, the organic solvent for that purpose is aprotic polar solvents including dimethyl-formamide, whereas acetone, benzene, cyclohexanol, etc., on the other hand, are used there for deposition of the resins. That is, the resins are insoluble in these latter organic solvents.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a photosensitive composition containing a polyimide as photosensitive component which is by itself soluble in low boiling organic solvents for general purpose use, typically methyl ethyl ketone, and capable of giving a negative type pattern upon development with an aqueous alkali solution.
According to the present invention, there is provided a photosensitive composition, which comprises polyimide, comprising a copolymer of two kinds of diamine compounds consisting of diaminopolysiloxane and a carboxyl group-containing diamine or three kinds of diamine compounds consisting of diaminopolysiloxane, a carboxyl group-containing diamine and an aromatic or alicyclic diamine with a 4,4′-(hexafluoroisopropylidene)-diphthalic acid dianhydride, a photo crosslinking agent and a photo acid-generating agent.
A polyimide comprising a copolymer of two kinds of diamine compounds consisting of diaminopolysiloxane and a carboxyl group-containing diamine or three kinds of diamine compounds consisting of diaminopolysiloxane, a carboxyl group-containing diamine and an aromatic or alicyclic diamine with a 4,4′-(hexafluoroisopropylidene) diphthalic acid dianhydride, can be produced by reacting two kinds of diamine compounds consisting of diaminopolysiloxane and a carboxyl group-containing diamine or three kinds of diamine compounds consisting of diaminopolysiloxane, a carboxyl group-containing diamine and an aromatic or alicyclic diamine with a 4,4′-(hexafluoroisopropylidene)diphthalic acid dianhydride, thereby once forming polyamic acid, and then polyimidizing the polyamic acid. The resulting polyimide can be formed into a photosensitive composition by adding a photo crosslinking agent and a photo acid-generating agent thereto.
DETAILED DESCRIPTION OF THE INVENTION
For diaminopolysiloxane, one component of two or three kinds of diamine compounds, which react with the carboxylic acid anhydride, compounds represented by the following general formula can be used:
where R is a divalent hydrocarbon group having 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms; R
1
to R
4
are each a lower alkyl group having 1 to 5 carbon atoms or a phenyl group; and n is an integer of 0 to 30, preferably 4 to 12.
The compounds include, for example, compounds whose R and R
1
to R
4
are the following substituents in combination:
R
R
1
R
2
R
3
R
4
(CH
2
)
3
CH
3
CH
3
CH
3
CH
3
(CH
2
)
4
CH
3
CH
3
CH
3
CH
3
(CH
2
)
3
CH
3
C
6
H
5
CH
3
C
6
H
5
p-C
6
H
4
CH
3
CH
3
CH
3
CH
3
Actually, the following commercially available products can be used: Toshiba Silicone products TSL9386, TSL9346 and TSL9306; Toray Dow-Corning product BY16-853U, Shinetsu Chemical product X-22-161AS, Nippon Unicar product F2-053-0 1, etc.
The carboxyl group-containing diamine for use in the present invention includes, for example, 3,5-diaminobenzoic acid, 2,5-diaminoterephthalic acid, 2,2′-bis(aminobenzoic acid), etc. These carboxyl group-containing diamines, when the produced polyimide is to be used as a photosensitive resin, can be used so that the carboxyl group content is about 0.6 to about 3.0% by mole, preferably about 0.7 to about 2.5% by mole in the repetition units [(a) and (b) or (a) to (c) which follow]. Below about 0.6% by mole, the polyimide will be less soluble in an aqueous alkali solution, whereas above about 3.0% by mole it will be too soluble therein.
The aromatic or alicyclic diamine for use in the present invention includes, for example, aromatic diamines such as 3,3′-bis(aminophenyl)-ether, 4,4′-bis(aminophenyl)ether, 1,3-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy) phenyl]sulfone, 4,4′- diaminodiphenyosulfone, 3,3′-diminodiphenylsulfone, etc. or alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane, 4,4′-bis(aminocyclohexyl)methane, 3,3′-bis(aminocyclohexyl)methane, etc.
When two kinds of diamine compounds are used, diaminopolysiloxane is used in a proportion of about 20 to about 80% by mole, preferably about 40 to about 70% by mole, whereas carboxyl group-containing diamine is used in a proportion of about 20 to about 80% by mole, preferably about 30 to 60% by mole, where total is 100% by mole. When less than about 20% by mole of diaminopolysiloxane is used, no film can be formed, whereas above about 80% by mole development by an aqueous alkali solution cannot be made anv more. When less than about 20% by mole of carboxyl group-containing diamine is used, light-unexposed regions will be insoluble in the aqueous alkali solution, whereas above about 80% by mole even light-exposed regions are soluble, but the difference in dissolution rate between the light-exposed regions and the light-unexposed regions will be smaller.
When three kinds of diamine compounds are used, diaminopolysiloxane is used in a proportion of about 20 to about 70% by mole, preferably about 30% to about 50% by mole, carboxyl group-containing diamine in a proportion of about 20 to about 70% by mole, preferably about 30 to about 50% by mole, and aromatic or alicyclic diamine in a proportion of about 10 to about 60% by mole, preferably about 20 to about 40% by mole, where total is 100% by mole. When the aromatic or alicyclic diamine is used in such a proportion, the polyimide resulting there from will have a higher light transmission in the ultraviolet zone, for example, a satisfactory photosensitivity even to a film as thick as 50 &mgr;m. When the aromatic or alicyclic diamine is used in a proportion of more than about 60% by mole, polyimide will have a reduced solubility in the lower boiling organic solvents for general purpose use.
Reaction between a mixture of diamine compounds and a 4,4′-(hexafluoroisopropylidene)diphthaiic acid dianhydride represented by the following formula:
is carried out preferably in an aprotic polar solvent such as dimethyl-formamide, dimethylacetamide, N-methyl-2-pyrrolidone, etc., but can be carried out even in a polar solvent such a
Chiang Lin-chiu
Lin Jenq-Tain
Sensui Nobuyuki
Baker & Daniels
Baxter Janet
Clarke Yvette M.
Nippon Mektron Limited
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