EP0113409A2
Expired / Lapsed
EP
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Method and composition for applying coatings on printed circuit boards, and process for making said composition
Assignee: International Business Machines Corp
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Filing: 1983-11-15
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Granted: —
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Expires: 2003-11-15
Abstract
Abstract A coating is produced by a method including screen-printing of a photopolymerizable composition on a printed circuit board, illuminating said composition to partially polymerize it and bake it to complete the polymerization. The composition used by said method contains a reaction product of a monoethylenically unsaturated carboxylic acid with a material of the group of epoxy resin and epoxidized novolak, a phenoxy resin, a thickening agent, a polyethylenically unsaturated compound, a photo-initiator and a solvent. The coating produced according to this invention can be used as solder mask.
Inventors
- 👤 Bernd Karl Appelt
- 👤 George Pershing Schmitt
- 👤 John Frank Shipley
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-10 02:20
CPC Classifications
C; C08; C08F; C08F299/00; C08F299/02; C08F299/026; C08F299/028; B; B23; B23K; B23K35/00; B23K35/22; B23K35/224; H; H05; H05K; H05K3/00; H05K3/22; H05K3/28; H05K3/285; H05K3/287; H05K2203/00; H05K2203/11; H05K2203/1105
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
53 words
Method for applying a coating to a printed circuit board, characterized by the following steps: a) screen-printing a photo-polymerizable composition onto said printed circuit board to form a coating, b) blanket illuminating the applied coating in order to at least partially polymerize the composition, and c) baking said coating to complete the polymerization.
Claim 2
Dependent Claim
53 words
Method for applying a coating to a printed circuit board, characterized by the following steps: a) screen-printing a photo-polymerizable composition onto said printed circuit board to form a coating, b) blanket illuminating the applied coating in order to at least partially polymerize the composition, and c) baking said coating to complete the polymerization.
Claim 3
Dependent Claim
89 words
Method according to claim l, characterized in that the screen-printing is done with a composition consisting of a reaction product of a monoethylenically unsaturated carboxylic acid with a material of the group comprising epoxy resin and epoxidized novolak, a phenoxy resin, a thickening agent, a polyethylenically unsaturated compound, a photo-initiator and a solvent, and wherein the ingredients are mixed according to the viscosity of the composition required for a desired screenability, and the curability of the composition, and the desired thickness and hardness of the coating to be produced.
Claim 4
Dependent Claim
48 words
Method according to claim 2, characterized in that the screen printing is done with a composition wherein as thickening agent colloidal silica, as polyethylenically unsaturated compound tri-methylolpropane tri-acrylate (TMPTA), as photoinitiator tert-butylanthraquinone (TBA), as mono ethylenically unsaturated carboxylic acid acrylic acid and as solvent Cellosolve acetate are used.
Claim 5
Dependent Claim
23 words
Method according to claim 2, characterized in that an anhydride of a dicarboxylic acid is added to the screenable composition prior to printing.
Claim 6
Dependent Claim
73 words
Method.according to claim 3, characterized in that said composition is mixed of between about 20 to about 50% by weight of acrylated epoxy resin, between about 28 to about 48% by weight of phenoxy resin, between about 2 and about 6% by weight of colloidal silica, between about 5 and about 15% by weight of TMPTA, and between about 0.5 and about 1.5% by weight of TBA, with the rest consisting of solvent.
Claim 7
Dependent Claim
55 words
Method according to claim 5, characterized in that said composition is mixed of about 30% by weight of an acrylated epoxy resin, about 38% by weight of a phenoxy resin,-,about 3% by weight of Cab-O-Sil, about 8% by weight of TMPTA, about 0.5% by weight of TBA and about 20.5% by weight of a solvent.
Claim 8
Dependent Claim
95 words
Method according to claim 4, characterized in that said composition is mixed of between about 31 and about 55% by weight of an acrylated epoxidized novolak, between about 5 and about 11% by weight of a phenoxy resin, between about 14 and about 20% by weight of nadic methyl anhydride as liquid anhydride of a carboxylic acid, between about 4 and about 5.5% by weight of colloidal silica, between about 4 and about 12% by weight of TMPTA, and between about 0.5 to about 1,5% by weight of TBA, with the rest consisting of solvent.
Claim 9
Dependent Claim
62 words
Method according to claim 7, characterized in that said composition is mixed of about 42% by weight of acrylated epoxidized novolak, about 8% by weight of phenoxy resin, about 15.5% by weight of nadic methyl anhydride, about 4,5% by weight of colloidal silica, about 8% by weight of TMPTA, about 1% by weight of TBA and about 21% by weight of solvent.
Claim 10
Dependent Claim
35 words
Method according to any one of claims 1 to 8, characterized in that the applied coating is illuminated with UV light having an intensity of 1.25 to 5 watts/ cm 2 of the coating surface.
Claim 11
Dependent Claim
33 words
Method according to any one of claims 1 to 9, characterized in that said coating is baked at a temperature between about 100 and about 180°C for about 20 to about 40 minutes.
Claim 12
Dependent Claim
40 words
Method according to claim 9 and 10, characterized in that the coating is illuminated with an intensity of about 3 watts/cm 2 of the coating surface and baked at a temperature of about 140 0 C for about 30 minutes.
Claim 13
Dependent Claim
52 words
Composition for producing coatings on printed circuit boards, characterized in that it consists of a reaction product of a monoethylenically unsaturated carbo- xyclic acid with a material of the group of epoxy resin and epoxidized novolak, a phenoxy resin, a thickening agent, a polyethylenically unsaturated compound, a photo- initiator, and a solvent.
Claim 14
Dependent Claim
52 words
Composition for producing coatings on printed circuit boards, characterized in that it consists of a reaction product of a monoethylenically unsaturated carbo- xyclic acid with a material of the group of epoxy resin and epoxidized novolak, a phenoxy resin, a thickening agent, a polyethylenically unsaturated compound, a photo- initiator, and a solvent.
Claim 15
Dependent Claim
53 words
Composition according to claim 12, characterized in that thickening agent is colloidal silica, said polyethylenically unsaturated compund is tri-methyl propane tri- acrylate (TMPTA), said photoinitiator is tert.-butyl anthraquinone (TBA), said monoethylenically unsaturated compound is acrylic acid and said solvent is chosen from the group comprising Cellosolve acetate, methyl ethyl ketone and butyl carbitol.
Claim 16
Dependent Claim
19 words
Composition according to claim 12 or 13, characterized in that the composition contains an anhydride of a dicarboxylic acid.
Claim 17
Dependent Claim
26 words
Composition according to claim 12, characterized in that said monoethylenically unsaturated carboxylic acid is selected from the group comprising acrylic acid, methacrylic acid and crotonic acid.
Claim 18
Dependent Claim
50 words
Composition according to claim 12, characterized in that the relative amount of monoethylenically unsaturated acid to the epoxy resin or.the epoxidized novolak, respectively, is chosen to be sufficient to react stoichiometrically with about 50 to about 100% of the epoxide functionality of this epoxy resin or this epoxidized novolak, respectively.
Claim 19
Dependent Claim
46 words
Composition according to claim 16, characterized in that the relative amount of monoethylenically unsaturated acid to said epoxy resin or said epoxidized novolak,respectively is chosen to be sufficient to react with about 75% of the epoxide functionality of said epoxy resin or said epoxidized novolak, respectively.
Claim 20
Dependent Claim
72 words
Composition according to claim 13, characterized in that the composition contains between about 20 and about 50% by weight of acrylated epoxy resin, between about 28 and about 48% by weight of phenoxy resin, between about 2 and about 6% by weight of colloidal silica, between about 5 and about 15% by weight of TMPTA, and between about 0.5 and 1.5% by weight of TBA / with the rest consisting of solvent.
Claim 21
Dependent Claim
51 words
Composition according to claim 18, characterized in that it contains about 30% by weight of acrylated epoxy resin, about 38% by weight of phenoxy resin, about 3% by weight of colloidal silica, about 8% by weight of TMPTA, about 0.5% by weight of TBA and about 20.5% by weight of solvent.
Claim 22
Dependent Claim
88 words
Composition according to claim 14, characterized in that it contains between about 31 and about 55% by weight of acrylated epoxidized novolak, between about 5 and about 11% by weight of phenoxy resin, between about 14 and 20% by weight of nadic methyl anhydride as liquid anhydride of the carboxylic acid, between about 4 to about 5.5% by weight of colloidal silica, between about 4 and about 14% by weight of TMPTA, and between about 0.5 and about 1.5% by weight of TBA, with the rest being solvent.
Claim 23
Dependent Claim
59 words
Composition according to claim 20, characterized in that it contains about 42% by weight of acrylated epoxidized novolak, about 8% by weight of phenoxy resin, about 15.5% by weight of nadic methyl anhdride, about 4.5% by weight of colloidal silica, about 8% by weight of TMPTA, about 1.0% by weight of TBA and about 21% by weight of solvent.
Claim 24
Dependent Claim
85 words
Process for making the composition according to any one of claims 12 to 21, characterized in that said material of the group of epoxy resin and epoxidized novolak is dissolved in the solvent and combined with the monoethylenically unsaturated carboxylic acid, that the two compounds are allowed to react at about 65 0 C for about 24 hours, that the reaction product is combined with a premix of the phenoxy resin, TMPTA and TBA, and that finally the colloidal silica is sheared into the mixture.
Claim 25
Dependent Claim
51 words
Process according to claim 23, characterized in that the relative amount of the acrylic acid to the epoxy resin or the epoxidized novolak, respectively, is chosen to be sufficient to react stoichiometrically with about 50 to about 75% of the epoxide functionality of this aepoxy resin or this epoxidized novolak, respectively.
References Cited (Backward Citations)
No citation records indexed.
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