Abstract: A plurality of semiconductor chips are first attached to a transparent mask by placing indica marks on the mask and then viewing the chips through the mask and aligning them to the indica marks. The chips, which are held on a vacuum pedestal, are then brought into contact with the mask and a temporary adhesive layer holds the chips to the mask. The vacuum is then released. The mask with the chips attached thereto is then aligned to a printed circuit (wiring) board having indica marks thereon by viewing through the mask and moving the chips and printed circuit board together until they contact each other. A permanent adhesive layer holds the chips to the printed circuit board. The temporary adhesive layer is then dissolved and removed from the chips.

Abstract: The plant comprises a first vacuum plate with openings on which a sheet may be fixed in an exact planar way by suction. A second plate with a slightly arcuated surface and turned towards the first plate is adjustable in height by two compressing cylinders and is pivotingly fixed to the structure. The second plate is also a vacuum plate and may be unrolled on the first plate. During the unrolling motion, the second plate is conducted by means of retractable bolts which are engaged into corresponding openings of the first plate. To compress two sheets, a first sheet is fixed in an exact planar way to the first plate by suction and transferred by an unrolling motion of the second plate thereon, the suction force of the plate being reduced and that of the second plate being correspondingly increased. A second sheet is then fixed to the first plate and cold- or hot-compressed according to the same unrolling process as the first sheet.

Abstract: A metallized laminate and process of manufacture wherein a metallic layer or underlying ink layer appears in a pattern on the laminate. The method in a specific embodiment involves the steps of forming a laminate by coating a heat stable release coat onto a carrier sheet; coating an ink layer in a pattern on the heat stable release coating so that at least portions of the release coat remain uncovered with ink, and applying a metallic layer over the release coat so that at least a portion of the metallic layer is in direct contact with and adheres directly to the release coat. Portions of the metallic layer may be removed by an etchant. A heat activatable adhesive layer is applied over the metallic layer. The laminate so formed is heat transferable from the carrier sheet to an article.

Abstract: A label which can be applied to envelopes or the like as an address label. The label, which is transparent, has an area treated so that it will detach a fused toner image from a carrier sheet printed xerographically or by a laser printer and cause the image to adhere to the label. Adhesive or chemical means are used to cause the image to transfer. In use, the label is first applied to a carrier sheet, on which is printed, the desired image, such as an address. When the label is removed from the carrier sheet, the fused toner image remains adhered to the label's underside, and the label can then be applied to an envelope. The label, being transparent, displays the image.

Abstract: In encapsulated-lens reflective sheeting of the prior art, a monolayer of glass microspheres is embedded in a binder layer, a specularly reflective layer underlies the microspheres, and a cover film encapsulates the microspheres, within a plurality of hermetically sealed cells. In the invention, a HMW thermoplastic binder film, affords improved structural integrity, greater toughness, and better conformability to irregular surfaces without cracking. The cover film preferably is of the same polymer family as said binder film.

Abstract: A sheet-like image recording material capable of forming a three-dimensional image. The image recording material comprises a sheet-like base material, a thermoexpansive coating layer formed by applying thermoexpansive microspheres onto the base material surface together with a binder, the thermoexpansive spheres being each formed by encapsulating a low boiling, vaporizable substance into a microcapsule of an thermoplastic resin, and a film layer bonded releasably onto the surface of the coating layer or the base material surface on the side where the coating layer is not provided. A toner image of a desired original image is formed on the film layer according to a electrophotographic method and then irradiated with light, whereby the toner image portion is heated selectively, so that the thermoexpansive layer expands to raise the image, thus affording a three-dimensional image. The toner image can be removed by peeling the film layer from the sheet-like image recording material.

Abstract: A three-dimensional image recording material for recording images in three dimensions and a three-dimensional image processing method using the said recording material. In forming the recording material, thermoexpansive microspheres each formed by encapsulating a low boiling, vaporizable substance into a microcapsule of a thermoplastic resin are applied onto sheet together with a binder. In forming a three-dimensional image, a desired image is formed on the thermoexpansive coating layer according to an electrophotographic method and then irradiated with light, whereby the toner image area is heated selectively and so that thermoexpansive coating layer expands to raise the image. Then, a laminate film having a heat transferable coloring material layer is put thereon followed by the application of heat and pressure to color the raised image area in a desired color.

Abstract: The invention consists of an improved method for placing single or multiple patterned layers of conductive material on a substrate. The method provided includes the step of placing or depositing a thin patterned layer of electrically conductive material on a substrate. The procedures used to deposit this layer include mechanically adhering the layer to the substrate then removing portions of it to form a pattern. They also include printing adhesive on the substrate and using it to peel a conductive pattern off of the surface of a transfer agent. After depositing the first conductive pattern, the process prints an insulating layer on top of it. The insulating layer has openings through which the next conductive pattern makes electrical contact with the first. Similarly, the process places other conductive layers and prints other insulating layers between them to produce multiple layers of conductive patterns. The multilayer circuit board provided includes a substrate.

Abstract: A temporary support with a transferable film composition coated on its surface is used in the manufacture of heat and pressure consolidated laminates to produce laminates of improved surface strength and functional properties. The film is composed of polyvinyl butyral resin and melamine resin. Additives may be included in the film composition for functional purposes and appearance.

Abstract: Gilding or relief-marking process which starts with any typographic, offset or other impression and converts it into relief of variable thickness, by the known thermography principle, but employing a hot-melt powder endowing the film forming the relief with adhesive properties capable, after it has solidified, of transferring and retaining on its surface a marking material.

Abstract: In a method of and apparatus for adhesive transfer, an image receiving web comprising a belt-shaped, release agent coated paper and a plurality of transfer sheets having adhesive surfaces and put side by side on the release agent coated paper in the longitudinal direction thereof is used. The transfer sheets are separated one after another from the release agent coated paper, and each separated transfer sheet is wound around a transfer roller with the adhesive surface facing out. The transfer roller is moved to contact a photosensitive material drum carrying a toner image formed thereon, and the toner image is transferred from the photosensitive material drum to the adhesive surface of the transfer sheet while the transfer roller and the photosensitive material drum are rotated.

Abstract: A method for manufacturing printed electrical circuits which comprise a substrate and copper foil applied thereto by hot embossing in a predetermined circuit pattern, said method comprising(a) providing a laminate which comprises the sequence of a printed circuit substrate, a heat activated adhesive layer, a copper foil and a carrier film which is electrically conductive,(b) passing an electrical current between two electrodes and through the carrier film wherein one electrode has sufficiently large film contact area whereby substantially no resistance heating results from the current density and the other electrode serves as an embossing tool and is of sufficiently small film contact area whereby sufficient resistance heating results from the current density to activate the adhesive layer to bond the copper foil to the substrate in the pattern of said other electrode, and(c) removing from the laminate the carrier film and such copper foil overlying areas where the adhesive was not heat activated thereby leav

Abstract: A process for the production of padding layers having a high degree of thermal insulation, and particularly suitable for use in clothing and furnishing, comprises the steps of producing, by means of carding machines, a layer or web comprising a mixture of polyester fibres with silicone treated fibers of the same or different nature. This layer or web is then resin coated on one side with a mixture of sticky plastic adhesives which, when polymerized, form a very soft and elastic film; on the other side of the same layer a non-sticky adhesive is sprayed or otherwise applied and the thus treated web is then subjected to a calendering operation at a temperature varying between predetermined limits. Subsequently, a layer of metal particles embedded in synthetic resins is applied to one or both sides of the said layer in such a way as to form a thermal barrier operable to reduce the transmission of heat by radiation and convection through the layer itself.

Abstract: A thermal-transfer recording method and an apparatus used for this method in which ink on an ink tape is heat-transferred in the form of a mirror image of a desired image to an intermediate recording sheet having a base film and an ink absorbing adhesive layer formed on the base film, and in which the intermediate recording sheet to which the mirror image has been heat-transferred is bonded to a desired recording medium at the surface of the ink absorbing adhesive layer.

Abstract: A method for making a sheet of resistive material having randomly oriented conductive fibers with a density of approximately 50 to 300 milligrams per square meter. The fibers are weighed, mixed with a solvent, contained in a non-turbulent state. The solvent is withdrawn under pressure through a porous film and backing. A sticky sheet material is placed in contact with the film for transferring the fibers from the film to the sheet.

Abstract: Method of selectively forming an aluminum evaporation film on a surface such as the surface of a container made of plastic film, paper, or glass and of stamping the aluminum evaporation film, by building up the aluminum evaporation film, effecting the stamping work on the aluminum evaporation film or providing the aluminum evaporation film on the surface of a container such as a glass bottle, such as by forming the aluminum evaporation film on one of two films or sheets, applying a hardenable or curable bonding agent meeting or in registry with letters and/or patterns provided on the other of the two films or sheets, then pasting up or joining the two films or sheets together, and thereafter when the bonding agent has hardened, separating the two films or sheets from each other and shifting the aluminum evaporation film to the bonding agent side containing film or sheet.

Abstract: A process for peeling a protective film off a thin article such as a silicon wafer is proposed. The film is peeled by sticking an adhesive tape to the protective film on the article and pulling it away from the article. The protective film is peeled only by the adhesive force of the adhesive tape.

Abstract: A transferable film composition coated on a temporary support is used in the manufacture of heat and pressure consolidated laminates to produce laminates of improved surface strength and functional properties. The film is composed of polyvinyl butyral resin and melamine resin which reacts with a resin in the laminates. Additives may be included in the film composition for functional purposes and appearance.

Abstract: An improved procedure for manufacture of optical replication products comprising the use of a thin amorphous coating of carbon as a protective coating which also facilitates release during replication, between master and replication members. Particular attention is given to controlling the compressive forces of the carbon layer to provide good mechanical coatings on suitable optical surfaces. Thereafter, the replicated members may themselves be coated with the carbon as a protective coating only or for further use as a release-promoting "submasters".

Abstract: A lift-off tape capable of being used many times which comprises a foundation and an adhesive layer provided on one major surface of the foundation, said adhesive layer containing a plasticizer capable of plasticizing a polyamide resin which is a main component of the vehicle of a correctable ink. The lift-off tape can be used many times to remove erroneous typed impressions of a correctable ink which contains a polyamide resin as a main component of the vehicle thereof.

Abstract: A method for producing a veneer which provides the appearance of a prized wood comprises the steps of applying thermoplastic contact adhesive layers both to the non-thermoplastic surface of the common wood veneer and to the thermo-adhesive surface of a hot stamping foil. The contact adhesive layers of the veneer and foil are united without heat or pressure and then heat and pressure are applied to the united veneer and foil to effect fusion thereof. Another aspect of the invention comprises a veneer produced by the foresaid method.

Abstract: A method for the preparation of selectively decorated resin films comprises applying a first primer coat to the entire area of the base film, then applying either a masking coat alone or one or more color coats followed by the masking coat, the masking coat applied to an area of the base film that will define the final selective decoration. The masking coated surface is thereafter metalized and the resulting composite is joined to a mask-removing film bearing a pressure-sensitive adhesive having a limited peel strength known as "soft peel". The process is completed by the separation of the respective films, with the mask removing film withdrawing from the base film the unwanted portions of the metal coat and its underlying masking coat, to leave a crisp, patterned decoration.The present process requires no solvents and is therefore environmentally preferred.

Abstract: An ink ribbon comprises an ink supporting member, an intermediate layer mounted on the ink supporting member, and ink mounted on the intermediate layer. The ink has supercooling property and is susceptible to softening or melting by heat, and the intermediate layer is adapted to reduce adhesion of the ink to the intermediate layer above a temperature at which the ink is softened or melted. A thermal-transfer recording apparatus best adapted for use of the ink ribbon described above, comprises a thermal head including a plurality of heating elements and being in sliding contact with the ink ribbon, the heating elements being adapted to be heated for predetermined patterns so that the ink of the ink ribbon in sliding contact with the thermal head is heated to be softened or melted into the predetermined patterns, and is transferred to the recording paper overlapping the ink ribbon.

Abstract: Lamination of a photopolymerizable film onto a substrate employs an intermediate nonphotosensitive liquid which is substantially all monomer.

Abstract: A system for preparing tissue blocks for sectioning in a microtome is provided. A vacuum-retracted membrane of plastic film material is used to draw a tissue block or specimen into planar contact with a polished platform that is positioned in a vacuum receptacle assembly. A cover plate forms a seal between the membrane and the vacuum receptacle assembly, whereupon a vacuum source is activated to retract the membrane against the tissue block and polished platform. The user adjusts any peripheral edges of the tissue block that are not properly oriented or in a planar position. The tissue block is frozen to the platform once it is properly oriented. The membrane is subsequently peeled away from the platform and the platform/block complex is placed into a mounting device and O.C.T. compound is applied thereto. The O.C.T. compound is also applied to a corrugated platform carried by the mounting device, and the polished and corrugated platforms are mated, with the O.C.T. compound and tissue block therebetween.

Abstract: A predetermined pattern is printed on a surface of a material on which a flock pattern is desired, using crosslinking type synthetic resin as the printing ink and utilizing the printing method such as the screen printing process. A solidly flocked paper is then applied on the pattern formed of the ink, and is heated and pressed together, so that the crosslinking reaction takes place in the synthetic resin. Thus, when the flocked paper is peeled off from the surface of the material, a flock pattern of the predetermined shape is formed thereon.

Abstract: In a process for transferring indicia from paper to a fabric backing member such as a T-shirt, of the type wherein an indicia carrier layer of tacky contact adhesive is bonded to the backing member by a thermoplastic elastomer layer, the combination of webs involved in the transfer process is supported through the various steps, including the water wash and at least the initiation of fusing, by a temporary support layer of heat-resistant water-impervious polymer having a non-silicone high release coating, and heat and pressure are applied through such layer to firmly fuse the thermoplastic elastomer layer along with the carrier layer and the indicia to the backing member prior to stripping of the temporary support layer. The firm fusing and the release action established by the non-silicone high release coating prevent distortion or destruction of any portion of the indicia during the stripping step.

Abstract: A magnetic recording medium having a magnetic coating containing therein ferromagnetic metal powder provided on a base film, wherein the magnetic recording medium being characterized in that the surface roughness of the magnetic coating, i.e., the surface roughness R.sub.rms (a unit of measurement of .mu.m) with respect to a waveform having a wavelength P in a range of from 3 to 50 .mu.m out of groups of waveforms constituting the cross-sectional waveform of the surface of the magnetic coating, satisfies the following equation.R.sub.rms .ltoreq.7.5.times.10.sup.-4 P+7.5.times.10.sup.-3where 3.ltoreq.P.ltoreq.50 .mu.m.

Abstract: A method and an apparatus for applying an emulsion onto a screen-printing plate are disclosed, in which an emulsion film having thereon an applying emulsion of a predetermined thickness is prepared, which film is closely contacted with the screen-printing plate on its printing side for applying the emulsion thereon. Preferably, a penetrable agent is supplied for facilitating the release and adhesion of the applying emulsion.

Abstract: An applique of a prepatterned film of alpha particle resistant material, such as polyimide, is applied to a semiconductor wafer. The prepatterned film covers only the critical areas e.g. those affected by alpha particle impingement. Bond pads and scribe streets are not covered by the applique.

Abstract: A hot stamping method enables the formation of very sharp edges and profiles of characters/numerals, patterns and the like upon a surface of a base plate. This method comprises a masking step making certain characters, numerals and patterns formed by a masking layer upon a surface of a base plate; a step of placing a foil sheet having an adhesive layer upon a surface of the masking layer and a surface of the base plate, and transferring a foil of the foil sheet to the surface of the base plate by means of heat and pressure; and a step of leaving the transferred foil upon the surface of the base plate and releasing the masking layer and the foil transferred to the surface thereof from the base plate.

Abstract: A method of applying and repairing veneers and the like comprises the following steps:sticking a sheet to the outside surface of the veneer;unsticking the veneer from its support;sticking the sheet to a substantially rigid transparent plate;repairing the veneer and then resticking it to its original support.For applying a previously made up mosaic coating, a transparent temporary support plate is used enabling the composition to be offered up for visual inspection prior to final fixing.

Abstract: A method for producing a hybrid integrated circuit includes steps of: applying an adhesive to an electronic part mounting conductor on an insulating substrate; adhering an electronic part to the applied adhesive and hardening the adhesive to temporarily fix the electronic part; fixing the temporarily fixed electronic part on the conductor with solder; and dissolving the hardened adhesive in a solvent and removing it. Upon being hardened, the adhesive can withstand the heat of molten solder and can be dissolved in a solvent and removed therewith.

Abstract: A process for peeling a protective film off a thin article such as a silicon wafer is proposed. The film is peeled by sticking an adhesive tape to the protective film on the article and pulling it away from the article. The protective film is peeled only by the adhesive force of the adhesive tape.

Abstract: A method of transferring a retroreflective pattern onto a fabric, wherein a retroreflective pattern transfer sheet comprising a base film, a temporary holding adhesive, a mass of transparent fine glass spheres partially embedded into the temporary holding adhesive, and a reflective film layer which covers the exposed surface of the transparent fine glass spheres and the exposed surface of the temporary holding adhesive present in the gaps between individual adjacent transparent fine glass spheres, is superposed on the surface of a fabric coated with a compression bonding adhesive in a predetermined pattern, with the reflective film layer side put in contact with the fabric surface, the portion of the transfer sheet which is opposed to the compression bonding adhesive into bond with the fabric, an outer portion of the sheet is subsequently stripped off, whereby only the portion thereof which is in bond with the fabric through the compression bonding adhesive is allowed to remain on the fabric to form the retro

Abstract: A process for fabricating display panels in which which comprises printing one surface of a pulp paper with a plurality of printed image layers exactly overlaying and aligned with each other bonding; the image bearing surface of the pulp paper bonded to one surface of a panel base; and removing the pulp paper so that the display image is transferred to and remains on the panel base.

Abstract: A process for producing a printed-wiring board is disclosed. The process involves providing a metal carried support surface and forming a resist pattern on the metal surface comprised of a silicone rubber material. The support surface where there is not resist is metal plated to provide metal plated surface portions which are contact bonded to a insulating base material by interposing an adhesive between the insulating base material and the metal surface portions or contact bonded to an uncured base material having an adhesive force. The contact bonding is carried out in order to transfer the metal surface portions onto the base material thus forming the conductor pattern on the base material and producing the printing-wiring board. The process eliminates the loss of expensive copper foil and provides a method by which the base material can be securely bonded to the metal portions forming the printed-wiring board.

Abstract: A method of manufacturing a thermal print head includes the step of coating a channel 12 of a fixture 10 with a first adhesive 26. Integrated circuit packages 20 are placed in the channel 12 with heating elements 22 disposed toward the bottom 14 of the channel 12. The packages 20 are held in position by a jig 30 while the adhesive 26 is thermally activated. A groove 52 in the face of a heat sink 50 is filled with a first part 54 of a two part adhesive and the integrated circuit packages 20 coated with the second part 56 of the two part adhesive. The alignment fixture 10 is positioned over the heat sink 50 activating the two part adhesive. The temperature of the assembly is elevated causing the first adhesive 26 to release and the second adhesive 54, 56 to further cure thus securing the packages 20 to the heat sink 50. Printed circuit cables 60, 70 are soldered to the packages 20.

Abstract: Simplified clamshell type printed wiring board production apparatus employs a reusable thin flexible plastic film as a carrier for a photopolymer coating layer for covering part of the conductive layer of a printed wiring board with a photoproduced pattern of high resolution. For solder mask coatings, two superimposed layers of polymer with diverse characteristics are employed to give significant advantages of high resolution, low cost, less production time with unskilled labor, better adherence to bare copper conductors, better environmental and electrical properties, and low tooling costs, without problems of outgassing and without the necessity for heating and cooling cycles during lamination. Low cost liquid photopolymer coatings are used advantageously by screen transfer with a scanning squeegee in an air free bond over circuit traces of considerable thickness in the absence of a vacuum.

Abstract: A method is described for transferring a thin tissue section affixed to a substrate by a first pressure-sensitive adhesive layer to a microscope slide which supports a second pressure-sensitive adhesive layer of polymerizable material. The tissue section is contacted to the second adhesive layer to form a laminate. Following polymerization of the second layer to form a positive bond between the tissue section and microscope slide, the substrate and first adhesive layer are completely removed to expose the tissue section, now affixed to the microscope slide by the polymerized second adhesive layer, for subsequent processing.

Abstract: Legends are built up from dry transfers in the usual way but on an intermediate carrier. Water or other liquid is applied to the rear surface of the intermediate carrier and an adhesive tape or sheet applied over the letters. The adhesive tape is then peeled away from the intermediate carrier bearing the letters which can then be adhered where desired, e.g. on a background scene or in a frame, using their own adhesive, whereafter the adhesive tape or sheet is peeled away to leave the letters looking as though they had been transferred there in the usual way.

Abstract: A method of making an improved laminated member such as a membership card, label, coupon or other die-cut member having indicia printed on one or both sides which is bonded to a base sheet for shipment of display and which when removed from the base sheet leaves no exposed adhesive on either the base sheet or indicia-bearing member. A pair of transparent plastic sheets are releasably joined together by thermal pressure and are attached to a carrier sheet by a pressure-sensitive adhesive. Indicia are printed in mirror image on an exposed side of one of the plastic sheets and the card or label is bonded by an adhesive to this mirror image printed side. Additional indicia are printed on the other side of the card or label. This laminated member then can be die cut forming a plurality of individual labels or cards on the carrier sheet.

Abstract: Edge-supported and fully supported membranes having substantially uniform thickness, and substantially parallel surfaces, and having the capacity to transmit at least about 90% of incident light with very little diffraction, dispersion or absorption of incident light are made by forming a polymer/solvent mixture, spin-coating a film of the polymer from the mixture onto a rotatable surface, which may have a release agent thereon, and, where a release agent is present, joining a frame or other support to the membrane and removing the membrane with its attached support from the surface. Apparatus for making such membranes includes a dispenser for dispensing a polymer/solvent mixture onto a rotatable support; a device for spinning the rotatable support at gradually increasing speeds from a first to a second speed; and a device for maintaining the speed of rotation of the support at the second speed until the membrane forms.

Abstract: An improved printed wiring board (PWB) with solder mask coatings is achieved by means of a two layer composite coating. One inner adhesive photopolymer layer is applied to the PWB in the liquid state, displacing air from PWB surface. The outer layer of the composite is dry and is carried on a thin plastic sheet and overlaminated onto the liquid inner layer, without the need for a vacuum laminator. The dry film solder mask so laminated is then exposed through a phototransparency to harden the light struck dry film solder mask and light struck inner layer photopolymer, thereby cojoining the dry film solder mask, inner layer and PWB surface. A solvent washout step removes unexposed dry film solder mask and unexposed inner layer photopolymer. This provides a faster process, requires less equipment, and improves adhesion to metal conductors. The outer layer need not be photoimaged.

Abstract: A tennis-ball is made by covering a spherical core with twelve substantially identical pentagonally-shaped pieces of a cover material. Before the pentagonally-shaped pieces are attached to the core, they are covered on their outermost surface by a removable layer of adhesive-impermeable barrier material (e.g. tissue paper). The barrier material restrains the movement of the pentagonally-shaped pieces when applied to the spherical core, so that a narrow uniform seam is obtained. When all twelve cover pieces are correctly positioned on the core, the barrier material is removed and the assembly subjected to a random rolling action to "finish" the ball.

Abstract: Floor and wall coverings having a pattern are made by coating a plastisol onto a sheet support, and simultaneously with a thermal activation of the plastisol to gelify it, bringing a transferable pattern on a paper layer into contact with the plastisol.

Abstract: An article is decorated by applying a coating to the surface of the article to be decorated, placing over and around the coated article a shrinkable film carrying a desired decoration, shrinking the film over the coated article to transfer the decoration to the article and then removing the shrinkable film leaving on the surface of the article the desired decoration or ornamentation.

Abstract: A method is provided for accurately laying down a well-defined decorative ink stripe on an elongated metal strip. In the method, a laminated hot stamp foil is calendered in printing engagement with the metal substrate strip between a grooved metal roller and a heated resilient roller having a peripheral printing tongue. The pressure of the tongue on the hot stamp foil precisely transfers the ink stripe onto the metal strip.

Abstract: Adhesive is applied to a substrate for a printed circuit board in a pattern corresponding to that of the printed circuit. If the adhesive is of the type which contains a solvent, the substrate and adhesive are heated after application of the latter in order to drive off the solvent. Subsequently, a thin foil of a material which is capable of bonding to a chemically deposited metal is pressed onto the adhesive. The adhesive is then permitted to set which causes those portions of the foil in contact with the adhesive to adhere tightly to the latter. Once the adhesive has set, the foil is peeled from the adhesive. The portions of the foil which contact the adhesive remain bound to the adhesive thereby forming a base which is capable of receiving a chemically deposited metal. The thus-coated substrate is immersed in a bath where an electrically conductive metal for forming the printed circuit is chemically deposited in a pattern corresponding to that of the adhesive and, consequently, of the printed circuit.

Abstract: An improved printed wiring board (PWB) with solder mask coatings is achieved by means of a two layer composite coating. One inner adhesive photopolymer layer is applied to the PWB in the liquid state, displacing air from PWB surface. The outer layer of the composite is dry and is carried on a thin plastic sheet and overlaminated onto the liquid inner layer, without the need for a vacuum laminator. The dry film solder mask so laminated is then exposed through a phototransparency to harden the light struck dry film solder mask and light struck inner layer photopolymer, thereby cojoining the dry film solder mask, inner layer and PWB surface. A solvent washout step removes unexposed dry film solder mask and unexposed inner layer photopolymer. This provides a faster process, requires less equipment, and improves adhesion to metal conductors. The outer layer need not be photoimaged.