Ciba-geigy Corporation

Ewald Losert

George E Green

John G Paul

Edward Irving

Hans Zweifel

Kurt Meier

Abdul-Cader Zahir

Christopher G Demmer

Heinz Rembold

Thaddeus Audykowski

Bernard Peter Stark

Anton Mentha

Nikolaus Jehle

Heinz Remabold

Markus Th/u/ Er

Positive-working photoresist compositions containing

Photoresist compositions

A positive photoresist is electrodeposited onto a substrate, exposed to actinic radiation in a predetermined pattern, and then exposed areas are removed by contact with a developer. When the substrate is a metal-faced laminate, the exposed metal surface may be etched and the residual electrodeposited layer removed by contact with a suitable solvent, optionally after a second, general, exposure to actinic radiation. Suitable electrodepositable positive photoresists include o-nitrocarbinol esters and o-nitrophenyl acetals, their polyesters and end-capped derivatives and quinone diazide sulphonyl esters of phenolic novolaks, having salt-forming groups in the molecule, especially carboxylic acid and amine groups. The process is suitable for the production of printing plates and printed circuits, especially circuits on both sides of a liminate sheet linked conductively through metal-lined holes in the sheet.

Process for the production of images after electrodeposition of positive

Uniform protective coatings, particularly solder resist masks, on printed circuit boards can be produced with coating compositions having a viscosity of 200 to 700 m Pas at 25.degree. C. and comprising a solution of a photosensitive, thermally curable, lacquer-forming substance, wherein there is additionally uniformly dispersed 5 to 50% by weight of a finely divided filler.

Photosensitive coating composition and the use thereof for protective

Polymers and, where present, conventional additives, are removed from organic solutions with activated carbon.

Process for purifying organic solutions

A layer of a liquid composition containing a compound (A) having in the same molecule at least one (meth)acryloyl group and at least one bicyclo[2.2.1]hept-2-ene-6-yl unit is exposed to actinic radiation so that the layer solidifies due to photopolymerisation of (A) through the (meth)acryloyl group(s), remaining, however, photocrosslinkable. When desired, the solidified layer is exposed, as through a negative, to a substantially greater amount of actinic radiation, the parts so further exposed becoming more highly photocrosslinked through the bicyclo[2.2.1]hept-2-ene-6-yl unit(s) and hence insoluble. An image is produced which can be developed by means of suitable solvents. Examples of (A) include 3-(methacryloyloxy)-2-hydroxypropyl bicyclo[2.2.1]hept-2-ene-6-carboxylate and 2-(acryloyloxy)ethyl methyl-5-carboxybicyclo[2.2.1]hept-2-ene-6-carboxylate.

Photopolymerisation process with two exposures of a single layer

In a three stage process, a layer of a liquid composition containing a compound (A) having in the same molecule at least one (meth)acryloyl group and at least one 2,3-disubstituted maleimido group is exposed to actinic radiation so that the layer solidifies due to photopolymerization of (A) through the (meth)acryloyl group(s), remaining, however, further photocrosslinkable. When desired, the solidified layer is exposed, as through a negative, to a substantially greater amount of actinic radiation, the parts so further exposed becoming more highly photocrosslinked through the disubstituted maleimido group(s) and hence insoluble. An image is produced which can be developed by means of suitable solvents. Examples of (A) include N-(2-(acryloyloxy)ethyl)-2,3-dimethylmaleimide and N-(3-(methacryloyloxy)-2-hydroxypropyl)-2,3-dimethylmaleimide.

Photopolymerization process employing compounds containing acryloyl

In a three stage process, a layer of a liquid composition containing a compound (A) having in the same molecule both at least one (meth)acryloyl group and at least one anthryl group is exposed to actinic radiation so that the layer solidifies due to photopolymerization of (A) through the (meth)acryloyl group(s), remaining, however, further photocrosslinkable. When desired, the solidified layer is exposed, as through a negative, to a substantially greater amount of actinic radiation, the parts so further exposed becoming more highly photocrosslinked through the anthryl group(s) and hence insoluble. An image is produced which can be developed by means of suitable solvents. Examples of (A) include 3-(acryloyloxy)-2-hydroxypropyl anthracene-9-carboxylate and its methacryloyl homologue.

A process for producing solder masks on double sided printed circuit boards, comprising conveying the boards beneath a free falling curtain of a pohotopolymer to form a thin layer on a surface of the board, irradiating with ultra violet light areas of the surface other than those that need to be soldered and then, by subsequent development, dissolving the unirradiated areas of the layer. The viscosity of the photopolymer is between 500 to 1200 mPa's at impingement on the surface of the circuit and the height of the curtain is selected so that the rate of flow of the polymer onto the circuit is between 60 to 160 m/min. Also the rate at which the circuits are conveyed beneath the curtain is greater than a rate slightly less than the rate at which the polymer flows onto the circuit.

Process for the production of solder masks for printed circuits

The products, which are based on polyepoxides, polymerize on exposure to actinic radiation and are useful in the preparation of printing plates for offset printing and of printed circuits, particularly multilayer circuits. They are formed by coupling two molecules of a polyepoxide by means of a dihydric phenol which contains a chalcone or chalcone-like grouping, such as 1,3-bis(p-hydroxyphenyl)prop-1-en-3-one or 1,5-bis(p-hydroxyphenyl)penta-1,4-dien-3-one, so sensitizing the material to the radiation, and then, to achieve polymerizability, ring-opening at least some of the residual epoxide groups so as to incorporate olefinic acyloxy groups (R.sup.6 CH.dbd.C(R.sup.5)COO--), such as sorboyl groups.

Polymerizable esters

The products, which are based on polyepoxide, polymerize on exposure to actinic radiation and are useful in the preparation of printing plates for offset printing and of printed circuits, particularly multilayer circuits. They are formed by coupling two molecules of a polyepoxide by means of a dihydric phenol which contains a chalcone or chalcone-like grouping, such as 1,3-bis(p-hydroxyphenyl)prop-1-en-3-one or 1,5-bis(p-hydroxyphenyl) penta-1,4-dien-3-one, so sensitizing the material to the radiation, and then, to achieve polymerizability, ring-opening at least some of the residual epoxide groups so as to incorporate olefinic acyloxy groups (R.sup.6 CH=C(R.sup.5)COO-), such as sorboyl groups.

Radiation polymerizable esters

A process for the manufacture of printed multilayer circuits by coating carrier films, which possess metal layers, with a light-sensitive material containing a compound with epoxide groups and with groups which can be cured by electromagnetic rays, by exposing the light-sensitive material through a transparent film which shows the negative image of the conductor traces to be produced, by developing with an organic solvent, by etching the metal layer and pressing the laminates together to form a multi-layer circuit. The parts of the light-sensitive layer which have been pre-cured by exposure to light are subjected to a thermal after-treatment using a curing agent for epoxide groups, whereby these parts are post-cured. These parts are not removed from the carriers films.

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Rheinfelden, Switzerland

Ewald Losert