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
2000-08-07
2002-08-13
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
C430S281100, C430S270100, C430S905000, C430S916000, C525S329500, C525S330100, C525S383000, C525S385000, C522S085000, C522S037000, C522S040000, C522S043000, C522S046000, C522S039000, C522S053000
Reexamination Certificate
active
06432616
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a water soluble polymer, and more particularly to a photoresist composition containing the water soluble polymer.
2. Description of the Prior Art
In recent years, technology of integrated circuits has progressed quite a lot, and photoresists have long been used for the preparation of printed circuit boards and solder masks. The resins used in the photoresist are mainly organic solvent soluble resins, and the photoresist is developed with organic solvents to form circuits. The conventional phohotoresist used for printed circuit boards contains about 40-70 wt % of organic solvent. During the exposing and developing process, about 60-80% of the organic solvent will evaporate into the air, which is detrimental to human health and environment. For the environmental concern, aqueous alkaline solutions has been developed as the developing reagent.
To further lessen the volatile organic compounds (VOCs) problem, some water soluble photoresists have been developed, such as acrylate latexes and water soluble epoxy resins. The water soluble photoresist can not only be dissolved in water, but also has the advantage of easier handling.
In U.S. Pat. No. 5,411,837, the waterborne photoresist is prepared by emulsion polymerization. A surfactant should be added to maintain the dispersion stability of latex. However, the surfactant easily pollutes the developing tank and affects the adhesion of the photoresist with copper. In U.S. Pat. No. 5,045,435, an alkaline reagent (such as ammonia) is used to partially neutralize a carboxyl group-containing acrylic copolymer which is water insoluble so as to convert it into a water soluble latex. However, the water soluble latex has low photosensitivity.
SUMMARY OF THE INVENTION
The object of the present invention is to solve the above-mentioned problems and to provide a water soluble polymer having high photosensitivity, good water dispersability, and storage stability.
Another object of the present invention is to provide a photoresist composition. When the photoresist composition is coated on a printed circuit board, then dried and exposed to UV light afterwards, it is not tacky and will not stick to the mask. In addition, it has good adhesion to the copper on the printed circuit board.
To achieve the above-mentioned objects, the water soluble polymer of the present invention is prepared by the following steps of:
(a) reacting a carboxyl group-containing polymer with an alkaline reagent so that a portion of the carboxyl groups are reacted in an amount sufficient to make the polymer water soluble; and
(b) reacting the polymer obtained from step (a) with an unsaturated bonds-containing epoxide and/or heteroatoms-containing epoxide so that 1 to 100 mole percent of the remaining carboxyl groups of the polymer are reacted with the epoxide to form ester groups via a ring-opening reaction of epoxides, wherein the heteroatom is selected from the group consisting of silicon, nitrogen, phosphorous, and sulfur.
The photoresist composition of the present invention includes the following components:
(1) 10 to 50 weight % of a photosensitive resin which is a water soluble polymer prepared by the following steps of:
(a) reacting a carboxyl group-containing polymer with an alkaline reagent so that a portion of the carboxyl groups are reacted in an amount sufficient to make the polymer water soluble; and
(b) reacting the polymer obtained from step (a) with an unsaturated bonds-containing epoxide and/or heteroatoms-containing epoxide so that 1 to 100 mole percent of the remaining carboxyl groups of the polymer are reacted with the epoxide to form ester groups via a ring-opening reaction of epoxides, wherein the heteroatom is selected from the group consisting of silicon, nitrogen, phosphorous, and sulfur;
(2) 0.1 to 10 weight % of a photoinitiator;
(3) 5 to 50 weight % of a photopolymerizable reactive monomer; and
(4) 30 to 75 weight % of water.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, the water soluble polymer is prepared by the following steps. First, a water insoluble carboxyl group-containing polymer is reacted with an alkaline reagent so that a portion of the carboxyl groups are reacted in an amount sufficient to make the polymer water soluble. Then, the obtained polymer is reacted with an unsaturated bonds-containing epoxide and/or heteroatoms-containing epoxide to form ester groups via a ring-opening reaction of epoxides. In this manner, side chains containing unsaturated bonds and/or side chains containing heteroatoms can thus be introduced into the polymer. Thus, the water soluble polymer of the present invention is obtained. By means of the ring-opening reaction of epoxides, 1 to 100 mole percent of the remaining carboxyl groups of the polymer are reacted. Therefore, the final water soluble polymer may or may not have carboxyl groups.
In the situation that unsaturated side chains are introduced into the polymer, when the water soluble polymer of the present invention is exposed to light to undergo photocuring, the high ratio of unsaturated bonds can increase the photosensivity of the polymer. Moreover, the introduction of side chains can also increase the flexibity of the polymer. In addition, in the situation that heteroatom side chains are introduced into the polymer, it may improve the adhesion between the polymer and the copper surface.
According to the present invention, the water insoluble carboxyl group-containing polymer can be a homopolymer or a copolymer of acrylic acids, acrylates, methacrylic acids, methacrylates, anhydrides or mixtures thereof. For example, it can be a copolymer of monomer A and monomer B. The monomer A can be acrylic acids, acrylates, methacrylic acids, methacrylates, anhydrides and mixtures thereof, and the monomer B is a styrene. The anhydrides suitable for use in the present invention include maleic anhydride, methyl maleic anhydride, endo-5-norbornene-2,3-dicarboxylic anhydride, and cis-1,2,3,6-tetrahydrophthalic anhydride.
In the present invention, the purpose of the alkaline reagent is to partially neutralize the carboxyl groups in the water insoluble polymer so as to make the polymer water soluble. The alkaline reagents suitable for use in the present invention include ammonium hydroxide (NH
4
OH; ammonia water), sodium hydroxide, potassium hydroxide, 4-methylmorpholine, 2-amino-2-methyl-1-propanol, 2-dimethylamino-2-methyl-1-propanol, monoethanol amine, N,N-dimethylethanolamine, methyldiethanol amine, and morpholine.
According to the present invention, after the water insoluble carboxyl group-containing polymer is treated with the alkaline reagent, the epoxide used to react with the carboxyl groups can be the unsaturated bonds-containing epoxide only or the heteroatoms-containing epoxide only. Also, the unsaturated bonds-containing epoxide and the heteroatoms-containing epoxide can both be used.
The unsaturated bonds-containing epoxide suitable for use in the present invention can be glycidyl acrylate, glycidyl methacrylate, p-epoxy-styrene, p-glycidyl-styrene, or allyl glycidyl ether.
As to the heteroatoms-containing epoxide, the heteroatom refers to silicon, nitrogen, phosphorous, and sulfur. Representative examples include 3-glycidyloxypropyltrimethoxy silane or &bgr;-(3,4-epoxycyclohexyl)ethyl trimethoxysilane.
According to the present invention, the ring-opening reaction of the epoxide and the polymer treated with the alkaline reagent is preferably conducted at the presence of a phase transfer catalyst. Representative examples of the phase transfer catalyst suitable for use in the present invention include tetrabutylammonium bromide, tetrapropylammonium bromide, tetramethylammonium bromide, tetrabutylphosphonium bromide, tetraphenylphosphonium bromide, benzyl triethylammonium bromide, ethyl trioctyl phosphonium chloride, methyl trioctyl ammonium chloride, tetraphenylphosphonium chloride, methyl triphenylphosphonium chloride, tetrabutylammonium chloride, tetrabutylammonium iodide, and tetraphenylpho
Chen Hsiu-Mei
Liu Yi-Hua
Song Tsing-Tang
Yang Shung-Jim
Baxter Janet
Industrial Technology Research Institute
Lee Sin J.
LandOfFree
Water soluble polymer and photoresist composition containing... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Water soluble polymer and photoresist composition containing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Water soluble polymer and photoresist composition containing... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2916204