Heat stable photocurable resin composition for dry film resist

• US 7,198,884 B2
• Filed: 07/01/2003
• Issued: 04/03/2007
• Est. Priority Date: 07/10/2002
• Status: Expired due to Fees

• Current Assignee: CIBA Specialty Chemicals
• Original Assignee: CIBA Specialty Chemicals
• Inventors: Ohwa, Masaki, Oka, Hidetaka, Taylor, James Philip
• Primary Examiner(s): Visconti; Geraldina
• Application Number:
  US10/520,701
• Publication Number:
  US 20050260520A1
• Time in Patent Office: 1,372 Days
• Field of Search: 430258-260, 430/262, 430/263, 430/285.1, 430/287.1, 430/288.1, 430/910, 430/311
• US Class Current: 430/311
• CPC Class Codes: G03F 7/027 Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds G03F7/075 takes precedence
• CPC Class Codes: G03F 7/029 Inorganic compounds; Onium compounds; Organic compounds having hetero atoms other than oxygen, nitrogen or sulfur
• CPC Class Codes: G03F 7/092 characterised by backside coating or layers, by lubricating-slip layers or means, by oxygen barrier layers or by stripping-release layers or means
• CPC Class Codes: G03F 7/105 having substances, e.g. indicators, for forming visible images
• CPC Class Codes: G03F 7/11 having cover layers or intermediate layers, e.g. subbing layers G03F7/091 - G03F7/093, B41N3/03 take precedence
• CPC Class Codes: G03F 7/161 using a previously coated surface, e.g. by stamping or by transfer lamination
• CPC Class Codes: Y10S 430/111 Polymer of unsaturated acid or ester

Abstract

The invention relates to a process for preparing a dry film resist by forming a photocurable resin composition onto a support film with a thickness of 1 to 50 μm and optionally laminate a protective film onto the photocurable composition layer to obtain a dry film resist; whereby the photocurable resin is formed from a homogeneous mixture comprising (a) from 20–90 wt % of an alkaline soluble binder oligomer or polymer; (b) from 5 to 60 wt % of one or more photopolymerizable monomers which are compatible with the oligomers and polymers of component (a); (c) from 0.01 to 20% by weight of one or more photoinitiators; (d) from 0 to 20% by weight of additives and/or assistants; and (e) from 0.1 to 10% by weight of a leuco triphenylmethane dye of the formula (I), wherein R¹ is a residue selected from (II), R² is C₁–C₁₂ alkyl or phenyl which may be mono-, di- or tri-substituted by C₁–C₆ alkyl, trifluoromethyl, C_1-6 alkoxy, C_1-6 alkylthio, halogen and nitro; R³ is hydrogen or C₁–C₁₂ alkyl; R⁴ to R⁹ independently of one another are hydrogen or C₁–C₁₂ alkyl; X is O, S, NH or N—C₁–C₁₂-alkyl; (a) to (e) being 100% by weight. The above composition is useful to avoid unfavourable colour generation during the heat lamination

Claims

1. A process for preparing a dry film resist, which process comprises forming a photocurable resin composition onto a support film with a thickness of 1 to 50 μ

m and optionally laminate a protective film onto the photocurable composition layer to obtain a dry film resist;

whereby the photocurable resin is formed from a homogeneous mixture comprising

(a) from 20–

90 wt % of an alkaline soluble acrylic polymer having carboxylic acid function as a pendant group and having a molecular weight of about 2,000 to 2,000,000, and an acid value from 50 to 600 mg KOH/g;

(b) from 5 to 60 wt % of one or more photopolymerizable monomers which are compatible with the oligomers and polymers of component (a);

(c) from 0.01 to 20% by weight of one or more photoinitiators;

(d) from 0 to 20% by weight of additives and/or assistants; and

(e) from 0.1 to 10% by weight of a leuco triphenylmethane dye of the formula I

2. A process according to claim 1, wherein in formula I

R¹ is a residue

3. A process according to claim 1, wherein the leuco triphenylmethan dye is 4,4′

-[(9-Butyl-9H-carbazol-3-yl)methylene]bis[N-methyl-N-phenylaniline of the formula

4. A process according to claim 1, wherein component d) includes a diaryliodonium of formula.

5. A dry film resist obtained by a process according to claim 1.

6. A process for preparing a dry film resist element comprising the steps of

(A) forming a photocurable resin composition layer made of ingredients (a)–

(e) according to claim 1 onto a support film with a thickness of 1 to 50 μ

m, and laminate a protective film onto the photocurable composition layer to obtain a dry film resist;

(B) removing the protective film before use, and thermally laminate the photocurable composition layer onto the surface of a desired substrate for the application of the dry film resist at 100–

150°

C.;

(C) exposure to radiation through a mask or by direct laser irradiation; and

(D) removing the support film and wash away the unexposed (uncured) area by development.

7. A dry film resist element obtained by a process according to claim 6.

8. A process according to claim 6 wherein component (e) is 4,4′

-[(9-butyl-9H-carbazol-3-yl)methylene]bis[N-methyl-N-phenylaniline of the formula

9. A process according to claim 6 for forming copper circuit pattern of printed circuit boards, LSI packaging etching resist or plating resist, for solder resist or for forming cell or electrode pattern in flat display panel applications.