Abstract: A method and apparatus for making a semiconductor device involves placing a semiconductor wafer in a position where two coherent light beams can interfere thereon. One of the coherent light beams is modulated by a hologram inserted in the path of the beam projected onto a surface of the semiconductor wafer. The other of the coherent light beams is also projected onto the same surface of the semiconductor wafer. The two interfering light beams form a pattern on a photoresist film found on the surface of the semiconductor wafer, which can be developed by photoresist techniques.

Abstract: A method of manufacturing a liquid crystal display device includes the steps of forming a transparent electrode on a surface of a substrate, patterning the transparent electrode, coating a photosensitive layer of resin on the patterned transparent electrode, radiating ultraviolet radiation on a region of the photosensitive layer which will serve as a spacer to provide a gap between the substrate and a companion substrate to be combined therewith, radiating weak ultraviolet radiation on the photosensitive layer from the reverse side of the substrate, and developing the photosensitive layer to form the spacer and an alignment film simultaneously.

Abstract: Non-tacky, smooth, structureless surfaces of photopolymer relief printing plates for flexographic printing, whose relief layers are prepared in a conventional manner by exposing the photopolymerizable relief-forming layers of flexographic printing plates imagewise to actinic light and washing out the unpolymerized, unexposed areas with a suitable solvent, are produced by a process in which the flexographic printing plates are after-treated with a liquid medium which contains elemental bromine or is capable of forming elemental bromine, and then washed with a neutralization bath, one or more paraffinsulfonates, fatty alcohol ethersulfates or alkyl phosphates or a cationic or anionic surfactant possessing one or more perfluorinated carbon chains being employed in the bromine-containing, liquid medium.The relief printing plates obtained according to the invention are used for flexographic printing.

Abstract: A method of passivating exposed junctions on a semiconductor device is provided by the use of fritted glass and a rapid heating device. The uniform distribution of heat from the rapid heating device is used to fire the fritted glass that is covering the exposed junction. The results of this combination is an increase in device yields due to less leakage across the junction.

Abstract: Photoresist apertures having tapered sidewalls can be provided by first opening the aperture in accordance with ordinary practice followed by the exposure of the photoresist to a suitable energy source such as a flood exposure to wideband light, the heating of the photoresist to round the peripheral edges of the aperture and the exposure of the thus pretreated photoresist to an environment which removes photoresist from the inside wall of the aperture until the desired tapered profile is obtained. In the preferred practice of the invention, the pretreated photoresist is removed from the inside wall of the aperture through exposure to a dry oxygen plasma etch.

Abstract: A method of lithography employing an electromagnetic wave having a very short wave length such as X-ray and a resist layer sensitive to that electromagnetic wave is disclosed. The irradiation process is divided into two steps. One step is selectively irradiating the electromagnetic wave, as in the prior art, to the resist layer in a desired pattern. The other steps is non-selective irradiation over the entire area of the resist layer. The latter step may be conducted with a plurality of workpieces such as semiconductor wafers simultaneously.

Abstract: A process for the production of patterns that consist of powders and that are positive with respect to the original is described, according to which a light-sensitive layer containing at least one 1,4-dihydropyridine compound is exposed imagewise, treated with a strong acid, post-exposed diffusely to produce tacky areas, and is subsequently toned.

Abstract: A process for the production of negative relief copies, wherein a photosensitive material comprising at least one o-quinone diazide and at least one quaternary ammonium compound is imagewise exposed, heated, and then uniformly exposed before developing, involves reduced heat-treatment temperatures and durations, and does not require the use of toxic amines.

Abstract: A method for making a dry planographic printing plate, which comprises: exposing through a negative transparency a dry negative working presensitized plate comprising a base substrate having provided thereon, in order, a photosensitive layer containing an orthoquinonediazide compound and a silicone rubber layer; developing the exposed plate; exposing the developed plate to light so as to make its exposure value not less than 5% of the exposure value at the time of the exposure through the negative transparency; and then treating the exposed plate with a basic compound.

Abstract: A process of forming sub-micrometer metallization structures on a substrate is provided. A layer of a photoresist on the structure is pattern irradiated with a reduced dosage of actinic radiation so that, upon development, recesses are formed therein which extend only partially through the photoresist layer. A first layer of metallization is deposited onto the structure at an oblique angle such that it does not completely coat the photoresist in the recesses. The structure is then flood irradiated with actinic light and developed to form openings to the substrate where the photoresist layer is not covered in the recesses. A second layer of metallization is then deposited at normal incidence. The second metallization breaks off and deposits isolated structures on the substrate through the openings. The photoresist layer and overlying layers of metallization are then removed by conventional lift-off technique.

Abstract: A process for modifying structural profiles produced by polymerization or depolymerization in resist layers. As a function of the acoustic impedance of the substrate carrying the resist layer, the structures are irradiated with an ultrasonic beam. An ultrasonic beam for which the substrate represents a high impedance is used in order to enhance the contrast of the structures. An ultrasonic beam for which the substrate represents a low impedance is used to weaken the contrast. An acoustic microscope is especially suitable for carrying out the process.

Abstract: A method for producing an ink jet head comprises providing ink pathways formed of a photosensitive resin on the surface of a substrate and laminating covering over said pathways, and said photosensitive resin is exposed to light and the unexposed portion thereof is removed, the covering is placed over said photosensitive resin, and thereafter said photosensitive resin is subjected to the curing treatment.

Abstract: A method for forming dielectric filled isolation trenches in a semiconductor substrate wherein the substrate is coated with a photopolymer layer which also fills the trenches. Depending on the type of radiation used, the photopolymer layer is masked except for the regions directly above the filled trenches. The structure is exposed to radiation through the mask, which is then removed. The unexposed portions of the photopolymer layer are washed away and heat is gradually applied to shrink the remaining photopolymer into the trenches until it becomes coplanar with the semiconductor substrate surface. A mask is used if the radiation is ultraviolet light, but no mask is required if electron beam or x-radiation is employed.

Abstract: A positive resist containing a weak base and polyvinyl phenol as a film forming component is deposited on a substrate, subsequently exposed imagewise, cured, blanket exposed and developed in a KOH solution at temperatures of less than 10.degree. C. The resist pattern thus obtained is exposed to light having a wavelength ranging from 300 to 320 nm and finally heat-treated at temperatures ranging from 150.degree. to 280.degree. C. The finished lift-off mask is dimensionally stable at temperatures of .ltoreq.280.degree. C. and does not emit liquid or volatile components when heated.During application of the lift-off mask, a material is blanket vapor deposited at a substrate temperature ranging from about 160.degree. to 250.degree. C. on the resist pattern having openings with overhanging walls. Subsequently, the resist pattern is dissolved in a sodium metasilicate solution, causing the material vapor deposited thereon to be lifted off, with the material deposited on the substrate directly remaining.

Abstract: A positive tone photoresist is obtained without a solvent development step. The resist is a polymer containing masked reactive functionality which is imagewise exposed to unmask the functionality then treated with a non-organometallic reagent to remask that functionality. Following flood exposure, the resist is treated with an organometallic reagent containing an element which forms a non-volatile oxide. It is then developed by means of oxygen reactive ion etching.

Abstract: A light-emitting display component has a light-emitting display layer made of a monomolecular layers of inclusion complex compounds each comprising host molecules and guest molecules.

Abstract: In manufacturing a composite having a conductive layer on the surface of a resin layer, the first resin layer of polyimide is formed on a substrate of alumina ceramic and, after a resin layer is thermally set by heating, a second resin layer of polyimide is then formed on the first resin layer and is dried. Then the surface of the second resin layer is subjected to selective photoetching by using a photomask having predetermined small opaque areas distributed, thereby to form unevenness including concaves formed as a result of the selective photoetching. The layered composite thus obtained is then heated so that the second resin layer is thermally set. Then catalyst nuclei are formed for electroless plating on the etched surface having the unevenness formed and then a conductive metallic layer is formed by an electroless plating process on the etched surface having the unevenness formed. As a result, a composite of the above described structure is provided.

Abstract: For the production of printing plates, in particular lithographic printing plates by exposing a photopolymerizable recording material imagewise to actinic light and then effecting development with an aqueous alkaline developer, it is proposed to use photopolymerizable recording materials possessing a photopolymerizable copying layer (L) applied on a dimensionally stable base, where, in addition to containing ethylenically unsaturated photopolymerizable low molecular weight compounds, one or more photoinitiators, dyes and/or pigments, and, if required, further additives and/or assistants, the said copying layer (L) also contains, as a binder, one or more oligomeric and/or relatively high molecular weight copolymers which are soluble or dispersible in aqueous alkaline media and are based on cyclic dienes, in particular unsubstituted or substituted cyclopentadiene or unsubstituted or substituted di- or tricyclopentadiene.

Abstract: The present invention relates to an image recording process which comprises a step of (i) imagewise exposing a layer containing at least silver halide of an image recording material comprising (a) silver halide, (b) a reducing agent capable of developing silver halide, (c) a photopolymerization sensitizing dye capable of being reduced into a leuco substance by said reducing agent, and (d) a polymerizable vinyl monomer, to light to form a latent image, a step of (ii) uniformly heating said recording material to form a photopolymerization sensitizing dye image in a part corresponding to said latent image, and thereafter a step of (iii) uniformly exposing a layer containing at least said formed photopolymerization sensitizing dye image and said polymerizable vinyl monomer to light to form a polymer image in the part where said photopolymerization sensitizing dye image is present, by photopolymerization.

Abstract: A process for the production of structures by the polymerization, or fragmentation of resist layers comprising the steps of effecting an incomplete exposure of the resist layer corresponding to the pattern of the structures, and of fully developing the structure in the resist layer by ultrasonic irradiation.An acoustic microscope is preferably used for the ultrasonic irradiation, whereby the formation of the structure in the resist layer may also be observed.

Abstract: A process is described for improving the quality of images which have been formed by screen printing a liquid photo curable photopolymer. Images formed by screen printing, especially heavy coatings such as solder masks on printed wiring boards, inherently have indistinct boundaries, and may have feathered edges and photopolymer smears. These indistinct boundaries are removed and the resolution improved by a process which utilizes the oxygen inhibition effect characteristic of selected photopolymers. Thus, a screen printed image can be 0.001 inches thick at the center of a line, tapering off to 0.0001 inch thick smears, and these smears may be eliminated by irradiating the entire image with a moderate amount light energy, which cures the thick image portion and leaves a liquid boundary layer on the order of 0.0001 inch thick due to the oxygen effect. When washed with a mild solvent the liquid layer is removed, including the smears, leaving the thick image portion undisturbed.

Abstract: A photopolymerizable composition comprised of an addition polymerizable material, a photoinitiator, a thermal addition polymerization inhibitor and a polymeric binding agent. The addition polymerizable material is comprised of a defined monoethylenically unsaturated acrylate and one or more non-gaseous compounds having at least two terminal ethylenic groups. The photopolymerizable composition displays superior flexibility and develops and strips more efficiently when compared to a like composition but in the absence of the acrylate. The photopolymerizable composition may be in the form of sheet or roll on a film support which can be laminated to a substrate and can be used in the preparation of printed circuit boards.

Abstract: A process for forming patterns with a negative type resist which comprises the steps of forming a negative type resist film made of quinone diazide oligomer having a polymerization degree of 10 or less, such as a quinone diazide sulfonic ester on a substrate, irradiating the resist film selectively with far ultraviolet rays having a wavelength of 180-300 nm to expose the above film, and then developing the film thus exposed by the use of a suitable developer such as a solution containing any one of an acetic ester, an alkyl ketone and cyclohexanone, and another process wherein the above described exposing step is carried out in such a manner that the quinone diazide sulfonic ester film is subjected to blanket exposure by means of ultraviolet rays having a longer wavelength than 300 nm, and then the resist film, thus exposed, is further subjected to selective exposure by means of far ultraviolet rays of 300 nm or less.

Abstract: A lift-off metal deposition process in which a high temperature polyimide layer (i.e. a polyimide having a high imidization temperature) is applied to a first polyimide layer. The two layers are anisotropically etched through a photoresist mask to form vias in the first polyimide layer. After application of a metal layer, the high-temperature polyimide layer is lifted off the first polyimide layer, which remains as a passivation layer.

Abstract: A printing plate consisting of a base portion, a mount portion and a relief portion made of a liquid resin which is sensitive to and curable by irradiated activating rays, the plate being prepared by use of a masking sheet formed with a transmitting pattern having a contour corresponding to and slightly larger than the pattern of a negative film, a semi-transmitting pattern positioned outside the transmitting pattern and having a large contour for transmitting irradiated activating rays upon attenuation, and a blocking surface positioned outside the semi-transmitting pattern and having an effect to block the activating rays to an extent not to cure the liquid resin layer.

Abstract: A mask which is resistant to a plasma etching treatment is formed by providing an etch resistant skin over a lithographically patterned radiation sensitive resist film present on a substrate. The etch resistant skin is formed by providing a layer of, for example, chromium on the patterned resist and on the exposed surface of the substrate, and then, baking so that the chromium reacts chemically with the resist to form the etch resistant skin around the patterned film. This method may be used for example to manufacture a photo mask using a chromium coated glass substrate, or during the manufacture of semiconductor devices on a semiconductor wafer substrate.

Abstract: This invention provides a process, and delineates typical materials to be used in that process, which enables the use of a precision radiation source to produce a microcircuit resist image accurate to a few micrometers or even fractions of a micrometer. In addition, the process of the invention provides for the dry development of this image, thus insuring the ability to create a finished resist structure exhibiting the same accuracy in dimensions.Specifically, the invention provides a process in which a positive or negative resist polymer is irradiated under low pressure using a precision radiation source such as an electron beam, masked ion beam, or focused ion beam to generate organic free radicals. After irradiation, the reactive resist polymer is exposed to oxygen or air to create peroxides or hydroperoxides.

Abstract: Process for photographic recording of selective areas of an original image, e.g., as equidensities and/or contour images, on a photohardenable material, e.g., (a) nongaseous monomer compound, (b) organic photoinitiator or photoinitiator/sensitizer system and (c) photoinhibitor activatable by ultraviolet radiation, which comprises in either order (A) exposing the photohardenable layer with desensitizing radiation, and (B) photohardening the layer with photohardening radiatiion, exposures (A) and (B) being imagewise exposures with the proviso that if exposure (B) is the first imagewise exposure, a nonimagewise final exposure is utilized.

Abstract: A method of fabricating a semiconductor device including the steps of forming a first layer of positive photoresist on a substrate surface; exposing selected portions of the photoresist; developing the photoresist to remove those portions which are exposed and leave those portions which are not. Then, plasma etching the substrate and the unexposed resist so that the etch fixes the photoresist. Subsequently forming a second layer of photoresist over the fixed first layer and over the etched substrate. Finally, exposing and developing selected portions of the second layer of photoresist in a pattern which is noncongruent with fixed first photoresist layer. This forms a selective double photoresist layer with the second layer over the fixed first layer, and may also provide single layers of either the first or second photoresist.

Abstract: A process for producing negative relief copies is disclosed in which a light-sensitive material, comprising (1) a light-sensitive ester or amide of a 1,2-quinone-diazide-sulfonic acid or of a 1,2-quinone-diazide-carboxylic acid and (2) a hexamethylol melamine ether is imagewise exposed, thereafter heated, and, after cooling, exposed again without an original, and subsequently developed by means of an aqueous-alkaline developer. The disclosed process permits the production of negative copies with the aid of a material which yields positive copies when it is processed in a conventional manner.

Abstract: A method of producing a decorative foil transfer design which eliminates the need for heat and pressure in the application of decorative foil to a surface. The method includes applying a foil assembly sheet to a substrate, applying lacquer and extender materials and a photo-sensitive emulsion over the foil assembly, exposing the photo-sensitive emulsion to a light through a design-bearing film, removing all material which does not underlie the hardened photo-sensitive emulsion, applying an adhesive, and transferring the foil design to the surface to be decorated.

Abstract: A process for producing negative relief copies is disclosed in which a light-sensitive material, consisting essentially of (1) a binder which is insoluble in water and soluble in aqueous-alkaline solutions and (2) a light-sensitive ester or amide of a 1,2-benzoquinone-2-diazide-4-sulfonic acid, a 1,2-benzoquinone-2-diazide-4-carboxylic acid, a 1,2-naphthoquinone-2-diazide-4-sulfonic acid, or a 1,2-naphthoquinone-2-diazide-4-carboxylic acid, is imagewise exposed, thereafter heated and, after cooling, exposed again without an original, and subsequently developed by means of an aqueous-alkaline developer. The disclosed process permits the production of negative copies with the aid of a material which yields positive copies when it is processed in a conventional manner.

Abstract: An improved lithographic printing plate and a process for production thereof, involving exposure to light, development, and burning-in treatment of a presensitized printing plate precursor, are disclosed, the improvement comprising applying an aqueous solution containing at least one compound selected from the group consisting of malic acid and salts thereof onto the printing plate precursor prior to the burning-in treatment; by the improvement, a lithographic printing plate having excellent printing durability can be produced.

Abstract: A layer of a liquid composition containing (A) a compound containing at least one heat-polymerizable, ethylenically-unsaturated group, (B) a photopolymerizable material, and (C) a thermally-activated free radical initiator for polymerization of (A), is heated to solidify the layer, and subsequently it is exposed to actinic radiation in a predetermined pattern and those parts of the layer that have not become photopolymerized are removed by treatment with a suitable solvent.An example of an unsaturated, heat polymerizable compound (A) is butanediol dimethacrylate. An example of a photopolymerizable material (B) is an epoxidized novolak of 2,2-bis(4-hydroxyphenyl)propane with triphenylsulfonium hexafluorophosphate. A typical thermally-activated, free radical initiator (C) is cumene hydroperoxide.The process is suitable for the manufacture of printing plates and printed circuits.

Abstract: An optical photolithographic process in which resist lines having widths in the micron and sub-micron range are produced without the use of a fine line photomask. A positive photoresist having an additive for image reversal is applied to the surface of a semiconductor substrate. The photoresist is exposed through a photomask to ultraviolet light. The edges of the opaque sections of the mask diffract the ultraviolet light, forming partially exposed areas between the exposed and unexposed areas formed in the photoresist. After development in a solvent to remove the exposed areas, the photoresist undergoes an image reversal process. The photoresist is first baked at 100.degree. C. for 30 minutes. During this bake step, the photoactive decomposition products present in the partially exposed areas react, freezing the solubility of the partially exposed areas with respect to that of the unexposed areas.

Abstract: A photoresist photolithographic process is disclosed which provides for a single development step to develop a dual layer photoresist for lift-off, reactive ion etching, or ion implantation processes requiring a precise aperture size at the top of the photoresist layer.The process involves the deposition of two compositionally similar layers, with the first layer having the characteristic of being soluble in a developer after exposure to light and baking, and the second layer having the characteristic of being insoluble in the same developer after having been exposed to light and baked. With these two distinct characteristics for the two layers of photoresist, the effective aperture for windows in the composite photoresist can be tightly controlled in its cross-sectional dimension in the face of large variations in the developer concentration and development time.

Abstract: Gravure printing plates comprising a plastic printing layer applied on a printing plate base are produced by a method wherein a solid photosensitive layer (L) firmly bonded on the printing plate base is exposed imagewise to actinic light, and the exposed layer is washed out with a developer and then subjected to thermal hardening to form the plastic printing layer. In this process, the photosensitive layer (L) employed contains, as the photosensitive component, a compound possessing two or more aromatic and/or heteroaromatic o-nitrocarbinol ester groups, and a compound which effects crosslinking and possesses two or more reactive groups which are capable of reacting with --COOH groups under the action of heat to form a covalent chemical bond.

Abstract: Gravure printing plates which are highly abrasion-resistant and scratch-resistant can be produced rapidly and simply from a photosensitive recording material by exposing the latter through a photographic positive, washing out the unexposed areas and drying the resulting gravure printing plate, if the photosensitive recording material employed, which comprises a photopolymerizable and/or photocrosslinkable layer (L) applied to a dimensionally stable base, contains finely divided, hard, abrasive particles in the layer (L), the surface of this layer, which subsequently constitutes the surface of the printing plate, has a peak-to-valley height of <2 .mu.m, and the materials of this layer are chosen so that, after exposure and development, it has a Vickers hardness of not less than 10 N/mm.sup.2, measured under load.

Abstract: A method for providing very narrow resolvable line widths on a semiconductor substrate surface involves initial overexposure of a positive working photoresist through a mask so as to not only expose the portions of the photoresist corresponding to the transparent areas of the mask but to also expose the outer periphery of the photoresist areas corresponding to the opaque areas of the mask. Through subsequent processing, the areas of the substrate surface corresponding to the originally unexposed areas of the photoresist are made available for use in semiconductor fabrication, such as areas to be oxidized to function as narrow electrical isolation areas.

Abstract: A negative-working image forming process which comprises uniformly exposing a photosensitive material comprising a support having thereon a sensitive layer comprising (i) an o-quinonediazide compound and (ii) a second compound, to actinic radiation which is able to convert the o-quinonediazide compound to the corresponding indenecarboxylic acid compound, and subsequent to said uniformly exposing imagewise exposing said exposed photosensitive material to a laser beam to thereby render the indenecarboxylic acid compound of the imagewise exposed areas convert to the corresponding indene compound and developing with an alkaline developing solution to dissolve out the unexposed area to the laser beam, wherein said second compound reduces the rate of dissolution of the laser exposed areas in the developing solution by converting the indenecarboxylic acid to the corresponding indene compound, whereby said image results.

Abstract: A method is provided for providing a polystyrene-tetrathiafulvalene (PSTTF)/deep-ultraviolet hydrid system which combines the advantages of E-beam or X-ray lithography systems with those of deep-UV conformable printing to produce low bias, high aspect ratio resist images over the topography of microelectronic devices.

Abstract: A method of forming a resist pattern, which comprises printing a predetermined pattern on a substrate by a lithographic technique using a resist ink curable by irradiation of an active energy ray and/or heating, said ink containing (1) a metal chelate resin obtained by reacting (a) at least one resin selected from the group consisting of alkyd resins, modified alkyd resins, fatty acid-modified epoxy resins, urethanized oils and maleinized oils and (b) a metal compound capable of forming a coordination bond using the resin (a) as a ligand and (2) a polymerizable compound containing at least two ethylenically unsaturated bonds per molecule; and curing the printed pattern by irradiating an active energy ray and/or by heating.

Abstract: Actinic radiation exposes photohardenable material in two steps whereby photohardenable material not present as a solid is exposed through a photomask prior to application to a substrate and in a second step is reexposed through the photomask after application of the material to the substrate.

Abstract: A method for producing a negative resist image is disclosed, which method comprises exposing a film of a diazo-type resist material, which is free from 1-hydroxyethyl-2-alkylimidazoline, to electron beam radiation in a predetermined pattern, heat treating said patternwise exposed resist film, subjecting said heat treated film to overall exposure to ultraviolet radiation and, then, developing the so treated film to remove the resist material in the area not exposed to electron beam radiation.

Abstract: A process is described for preparing relief images, in which a light-sensitive material composed of a support and a light-sensitive layer which contains as essential constituents(a) a compound which has at least one C-O-C bond which is cleavable by acid,(b) a compound which forms a strong acid on irradiation and(c) a binder which is insoluble in water and soluble in aqueous-alkaline solutions is imagewise irradiated, warmed to an elevated temperature, cooled down and then irradiated over its entire area, whereafter those parts of the layer which have not been imagewise irradiated are then washed out by developing. The process makes it possible to prepare positive or negative copies by means of the same light-sensitive material in a simple way.

Abstract: Phosphor characters to supply feedback information for an automatic convergence system are applied to the gun side of the shadow mask of a color cathode ray tube by a method of applying layers of a positive-working photoresist and phosphor, exposing the layers through a positive photomask, back exposing to clear the shadow mask apertures, developing to remove the exposed areas, and baking to remove the photoresist.

Abstract: A method of manufacturing a semiconductor device in which a photosensitive lacquer layer is developed in a lye solution, and comprises a polymeric material and a sensitizer with a diazo group and a ketone group. This lacquer layer is formed on a substrate surface. After a patterning irradiation, but before development, the lacquer layer is subjected to an intermediate treatment comprising two irradiations. These irradiations result in that differences in solubility in lye are obtained in the direction of thickness in the parts of the lacquer layer which were not exposed during the patterning irradiation. In this manner, it is possible to realize lacquer patterns with different profiles.

Abstract: There is disclosed an improved integral optical device of the type produced by creating optical patterns in porous glass bodies, especially patterns involving gradient refractive index distributions. The optical strength of an element, such as a lens, in such an optical pattern is increased by treatment with a polymerizable, organo functional silicone fluid while the matrix glass is sealed.

Abstract: The invention relates to a process for the burning-in of positive-working, light-sensitive layers, containing diazo compounds, during the preparation of offset printing forms, by heating the printing plate. In this process, the light-sensitive layer is treated, after exposure and development, with electromagnetic radiation having an infrared fraction, a fraction in the visible region, and an ultraviolet fraction.

Abstract: A permanent curl is provided in flexographic printing plates comprising a flexible sheet support and a photosensitive layer of a photopolymerizable elastomeric composition having a dry thickness of about 0.005 to 0.250 inch wherein after liquid development the printing plate is dried, 20.degree. to 80.degree. C. for at least 0.25 hour, and is postexposed by overall actinic radiation exposure for 1 to 30 minutes, at least the postexposure occurring while the printing plate is present on a curved surface, e.g., a printing cylinder. The process is useful for rubber and block copolymer-containing printing plates.