Abstract: A thermally imagable article comprises a substrate on which is coated a positive working heat-sensitive composition comprising a hydroxyl group-containing polymer and a heat-labile moiety which decreases the developer solubility of the composition as compared to the developer solubility of the composition without the heat-labile moiety, wherein the heat-sensitive composition does not comprise an acid generating moiety. The invention also provides novel positive working compositions comprising heat-labile moieties, and imagable articles comprising said compositions.

Abstract: A composition used as a resist in the manufacture of electronic parts, for example printed circuits, and which is rendered soluble in a developer by pattemwise delivery of heat, comprises a polymer and optionally an infrared absorbing compound. However in contrast to conventional compositions no compound is present which alters the solubility of the polymer in an aqueous developer.

Abstract: An imagable article comprises a thermally imagable coating on a substrate, the coating comprising a radiation absorbing compound and a metal compound which is thermally decomposable, to form a metal. The imagable article is imagewise exposed to electromagnetic radiation, which is converted to heat by the radiation absorbing compound. The imaged article is then subjected to a developer, and in regions that have been exposed the thermally decomposable metal compound is decomposed to elemental metal, and regions that have not been exposed dissolve in the developer leaving behind the regions of elemental metal.

Abstract: Phenolic resin compositions formulated for use in lithographic exposure processes are given a heat treatment at 40-90° C. for at least 4 hours shortly after their coating onto lithographic substrates, to produce lithographic printing forms. It is found that such a heat treatment improves later exposure processes, in particular by rendering the sensitivity of the compositions less variable, over time.

Abstract: A method of making a mask or an electronic part, for example a printed circuit, comprises the steps of delivering heat in a desired pattern to a precursor of the mask or electronic part, the precursor comprising a surface coated with a coating, the coating comprising a heat-sensitive composition itself comprising an aqueous developer soluble polymeric substance and a compound which reduces the aqueous developer solubility of the polymeric substance, wherein the aqueous developer solubility of the composition is not increased by incident UV radiation but is increased by the said delivery of heat; then developing the precursor to remove heat-sensitive composition in regions to which the heat was delivered. In the case of a printed circuit precursor the surface may then be etched in conventional manner to yield the required printed circuit.

Abstract: A precursor for electronic parts, for example printed circuit boards, has a negative-working thermally-imagable layer on a substrate, for example a copper board or semiconductor. The layer comprises a cross-linking agent, a thermally-activated acid generator, and a polymeric substance containing polyvinylphenol units and alkyl acrylate units. Such as layer has improved mechanical properties with maintenance of good imaging properties.

Abstract: A composition used as a resist in the manufacture of electronic parts, for example printed circuits, and which is rendered soluble in a developer by patternwise delivery of heat, comprises a polymer of general formula (I), wherein R1 represents a hydrogen atom or alkyl group, R2 represents a hydrogen atom or alkyl group, R3 represents a hydrogen atom or alkyl group, and R4 represents hydroxyalkyl group, and wherein the ratio n/m is in the range 10/1 to 1/10.