Abstract: The etching mask 80 for screen printing according to one embodiment of the present invention includes aliphatic polycarbonate. Further, the method of producing an oxide layer (the channel 44) according to one embodiment of the present invention includes: an etching-mask forming step of forming a pattern of the etching mask 80 including aliphatic polycarbonate; a contact step of, after the etching-mask forming step, contacting the oxide layer with a solution for dissolving a portion of the oxide layer (the channel 44) which is not protected by the etching mask 80; and a heating step of, after the contact step, heating the oxide layer (the channel 44) and the etching mask 80 to or above a temperature at which the etching mask 80 is decomposed.

Abstract: The present disclosure provides an organic sulfur acid-free composition containing a benzoxazine, phenolic compound and nitrogen-containing heterocyclic compound. The organic sulfur acid-free composition, upon curing at temperatures as low as 130°-140° C., renders void free cured articles having well balanced thermal, chemical and mechanical properties. The organic sulfur acid-free composition may be used in a variety of applications, such as in coatings, structural and non-structural composites and encapsulating systems for electronic and electrical components.

Abstract: A method of forming an electric wiring includes forming a trench on a substrate and ejecting first ink and second ink into the trench. The second ink contains a conductive material. The method includes heating the substrate to sinter the second ink such that a tunnel is formed in a lower portion of the trench by evaporation of the first ink, and the conductive material forms the electric wiring in an upper portion of the trench.

Abstract: This invention is directed to a polymer thick film conductor composition. The polymer thick film (PTF) conductor composition may be used in applications where significant stretching is required, particularly on highly permeable substrates. A particular type of substrate which is suitable is a woven polyester coated with polyamide. An electrical circuit containing a conductor formed from the composition and a process to make such a circuit are provided.

Abstract: This invention provides a method for using a polymer thick film conductor composition to form an electrical conductor in an electrical circuit, the method subjecting the deposited thick film conductor composition to photonic sintering. The invention also provides a method for reducing the resistance of an electrical conductor formed from a polymer thick film conductor composition, the method comprising the step of subjecting the electrical conductor to photonic sintering. The invention further provides devices containing electrical conductors made by these methods.

Abstract: An object with a coating comprising: a) covalent bonds formed by reaction of a thiol group and a carbon-carbon double bond, b) covalent bonds formed by reaction of a thiol group and epoxide group, c) covalent bonds formed by a reaction of a carbon-carbon double bond and an epoxide group, said coating comprising a first primer coating and a second coating, said coating comprising covalent bonds between said first and second coatings, said first primer coating comprising covalent cross links between compounds, in the first coating the fraction (r3=ta/tc) of unreacted thiol groups (ta) to thiol groups which have reacted to form a covalent bond (tc) does not exceed 0.11, wherein the half height peak width of tan delta does not exceed 30° C. Advantages of the dual cure composition is that excellent strength is obtained and that the second curing is slow compared to the first initial curing.

Abstract: A method of forming a heating element includes depositing a conductive ink of silver particles in an epoxy resin on a dielectric film to create a conductive circuit, and heat curing the conductive circuit to achieve a resistivity of the heating element less than 1.68×10?6 ohm·meter. An aircraft heated floor panel includes at least one floor panel of an aircraft includes a conductive circuit positioned within the floor panel having a conductive ink of silver particles in an epoxy resin on a dielectric film.

Abstract: The present invention relates to an insulating adhesive composition for metal printed circuit board, an adhesive-coated metal plate using the same, and a method for manufacturing the adhesive-coated metal plate. The adhesive composition according to the present invention forms an adhesive layer that is excellent in terms of adhesion to a copper foil, electrical insulating properties, and thermal resistance. The composition contains a specific epoxy resin, a curing agent and alumina. According to the present invention, in coating the metal plate with the solvent type adhesive, a roll coating method is used to perform a continuous coating process on the metal plate, thereby improving productivity when compared to the general method using a sheet type adhesive film.

Abstract: The invention is directed to a polymer thick film positive temperature coefficient carbon resistor composition consisting essentially of; (a) organic medium consisting of: (i) a fluoropolymer resin consisting of a copolymer of vinylidene difluoride and hexafluoropropylene; and (ii) an organic solvent consisting of triethyl phosphate; and (b) conductive carbon powder. The composition may be processed at a time and temperature necessary to remove all solvent. The invention is further directed to positive temperature coefficient (PTC) circuits comprising the composition of the invention which has been dried to remove the solvent and to articles, e.g., mirror heaters and seat heaters, containing such PTC circuits as well as a method for making such PTC circuits.

Abstract: The system of the present invention includes a conductive element, an electronic component, and a partial power source in the form of dissimilar materials. Upon contact with a conducting fluid, a voltage potential is created and the power source is completed, which activates the system. The electronic component controls the conductance between the dissimilar materials to produce a unique current signature. The system can also measure the conditions of the environment surrounding the system.

Abstract: A polyimide is formed by dehydrating a polyamic acid. The polyamic acid is formed by polymerizing a diamine and a fluorine dianhydride. The diamine is 2,2?-bis[4-(4-aminophenoxy) phenyl] propane, and the fluorine dianhydride is 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride. When a color of the polyimide is defined by Lab color space, b component is set from about ?10 to about +10. The disclosure further relates to a copper-clad laminate, a flexible printed circuit, and a method for manufacturing the flexible printed circuit.

Abstract: An object of the present invention is to provide (i) a polyimide precursor composition which is curable at a low temperature (not more than 250° C.) and which has a low viscosity despite having a high concentration, and a production method thereof, (ii) a polyimide coating film obtained from the polyimide precursor composition and having good properties, and a production method thereof, (iii) a photosensitive resin composition prepared by use of the polyimide precursor composition, and a production method thereof. The object of the present invention can be attained by a polyimide precursor composition containing an imidized tetracarboxylic acid having a specific structure and an isocyanate compound having a specific structure, or optionally a diamine.

Abstract: This invention provides a method for using a polymer thick film conductor composition to form an electrical conductor in an electrical circuit, the method subjecting the deposited thick film conductor composition to photonic sintering. The invention also provides a method for reducing the resistance of an electrical conductor formed from a polymer thick film conductor composition, the method comprising the step of subjecting the electrical conductor to photonic sintering. The invention further provides devices containing electrical conductors made by these methods.

Abstract: This invention provides a polymer thick film conductor composition comprising (a) a solder alloy powder selected from the group consisting of (i) a tin, silver, and copper alloy powder, (ii) a fin and bismuth alloy powder, and (iii) mixtures thereof, (b) a metal selected from the group consisting of silver, copper, gold, aluminum and mixtures thereof, and (c) an organic medium comprising a thermoplastic resin dissolved in an organic solvent, wherein the solder alloy powder and the metal are dispersed in the organic medium.

Abstract: A sensor assembly with a protective coating and a method of applying the coating is disclosed. The sensor assembly includes a sensor, a first conductive lead extending from the sensor, a second conductive lead extending from the sensor, and a protective coating encapsulating the sensor and portions of the first conductive lead and the second conductive lead proximate to the sensor, wherein the protective coating comprises a fluoroelastomeric polymer. The coating is applied by immersing the sensor assembly into a cooled fluoroelastomeric polymer and then withdrawing the sensor assembly.

Abstract: Disclosed is a resin composition, which comprises a thermosetting resin contained therein in an amount of 40 volume % or more, and a wax contained therein in an amount of 5 to 30 volume %, wherein: the thermosetting resin exists in liquid form at room temperature; and the wax exists in powder form at room temperature and has a melting point of 70 to 150° C., and wherein the resin composition has a viscosity of 50000 to 150000 mPa·s as measured at room temperature.

Abstract: Water-soluble electrically conductive polymers and a composition comprising such polymers are provided. Also, an electrically conductive layer or film formed from the composition, and articles comprising the electrically conductive layer or film are provided. The electrically conductive polymers according to the present disclosure have one or more hydrophilic side chains. Hydrophilic side chains are covalently bonded to the conductive polymers, which allow the polymer to be stable at high temperature. Thus, the stability of electrical conductivity is prolonged. Depending on the concentration of hydrophilic side chains, the conductivity may be changed. The hydrophilic side chains provide a successful way to fabricate a ductile film exhibiting tunable conductivity. Furthermore, high levels of surface-resistance uniformity can be achieved in the field of coating technology that uses eco-friendly water-based solvents to uniformly and quickly coat the conductive polymer on to plastic film surfaces.

Abstract: A method of production of a multilayer circuit board comprising using a curable composition which contains a heat curable resin and curing agent (I) to form an uncured or semicured resin layer on a board (step A), then bringing a curing agent (II) able to substantially to cure the heat curable resin at a temperature at which the curing agent (I) cannot substantially cure the heat curable resin into contact with the surface of the resin layer, then heating the resin layer at a temperature at which the curing agent (I) cannot substantially cure the heat curable resin and the curing agent (II) can substantially cure the heat curable resin (step B), next heating and curing the resin layer at a temperature at which the curing agent (I) can substantially cure the heat curable resin to form an electrical insulating layer (step C).

Abstract: An object of the present invention is to provide an optical film exhibiting a preferable wavelength dispersion and capable of being formed comparatively thinly. The present invention is an optical film containing the repeating unit represented by the following general formula (II). In the formula (II), A, A?, B, and B? each denote a substituent, a, a?, b, and b? denote the number of substituents of the corresponding A, A?, B, and B?. A, A?, B and B? each independently denote a halogen or an alkyl group having 1 to 4 carbon atoms. R1 and R2 denote a halogen, an alkyl group having 1 to 10 carbon atoms, and the like. X denotes —CO—, —SO2—, and the like.

Abstract: Disclosed is a photosensitive resin composition which has excellent concealing properties for appearance defects of a circuit and the like, while having excellent coloring power and resolution that enable the formation of a high-resolution solder resist layer. Specifically disclosed is a photosensitive resin composition which contains a perylene coloring agent, a coloring agent that is in a complementary color relation with the perylene coloring agent, a carboxyl group-containing resin, a compound that contains two or more ethylenically unsaturated groups in each molecule, and a photopolymerization initiator.

Abstract: A thermosetting resin varnish that includes a thermosetting resin composition of an uncured semi-IPN composite having compatibilized with one another (A) a polyphenylene ether, (B) a butadiene polymer which contains in the molecule thereof 40% or more of a 1,2-butadiene unit having a 1,2-vinyl group in the side chain thereof, and which is not chemically modified, and (C) a crosslinking agent; (D) an inorganic filler; and (E) a saturated thermoplastic elastomer. Also, a resin varnish for a printed circuit board, a prepreg, and a metal-clad laminate, using the thermosetting resin varnish.

Abstract: The use of at least one diazonium salt bearing an initiator function, for forming an undercoat obtained by grafting a graft derived from the diazonium salt and bearing an initiator function at the surface of a conductive or semiconductive material on the undercoat, and for forming on the undercoat a polymeric layer obtained by polymerization, in particular free radical polymerization, in situ of at least one monomer, initiated from the initiator function.

Abstract: A resin composition is provided. The resin composition comprises: an epoxy resin; a hardener, which comprises a melamine derivative of Formula I: wherein, R is the same with or different from each other and has the formula of R1 and R2 are individually selected from a group consisting of H, a halogen, a substituted or unsubstituted C1-C15 alkyl group, a substituted or unsubstituted C1-C15 aloxy group, a substituted or unsubstituted. C3-C15 cycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C6-C20 aryloxy group, a substituted or unsubstituted C1-C15 unsaturated hydrocarbyl group, a naphthol group, a phenanthrenol group, and a dicyclopentadiene group, with a proviso that R2 is not H; and m is 1 or 2, wherein the amount of the hardener is about 20 parts by weight to about 150 parts by weight per 100 parts by weight of the epoxy resin.

Abstract: Provided is a thermosetting resin composition which can be used for the production of printed circuit boards, having good dielectric properties in high frequency bands so that transmission loss can be significantly lowered, having excellent heat resistance after moisture absorption and thermal expansion properties, and satisfying peeling strength between the resin composition and metal foil. The present invention relates to a thermosetting resin composition of a semi-IPN composite, comprising (A) a polyphenylene ether, and a prepolymer formed from (B) a chemically unmodified butadiene polymer containing 40% or more of a 1,2-butadiene unit having a 1 2,-vinyl group in a side chain of a molecule and (C) a crosslinking agent, in a compatibilized and uncured state; and a resin varnish, a prepreg and a metal clad laminated board using the same.

Abstract: A fused filler and method for manufacturing the same are provided. The fused filler comprises about 50 wt % to about 60 wt % SiO2, about 10 wt % to about 20 wt % Al2O3, about 20 wt % to about 30 wt % B2O3 and about 1 wt % to about 5 wt % oxides of IA/IIA metals. The fused filler can be used in a resin composition for preparing prepregs and printed circuit boards.

Abstract: An electrical component includes a conductive substrate, a tin layer formed on the substrate, and a barrier coating formed on the tin layer to impede tin whisker growth. The barrier coating includes a polymer matrix, and abrasive particles that are dispersed about the matrix.

Abstract: An object of the present invention is to provide an optical film exhibiting a preferable wavelength dispersion and capable of being formed comparatively thinly. The present invention is an optical film containing the repeating unit represented by the following general formula (II). In the formula (II), A, A?, B, and B? each denote a substituent, a, a?, b, and b? denote the number of substituents of the corresponding A, A?, B, and B?. A, A?, B and B? each independently denote a halogen or an alkyl group having 1 to 4 carbon atoms. R1 and R2 denote a halogen, an alkyl group having 1 to 10 carbon atoms, and the like. X denotes —CO—, —SO2—, and the like.

Abstract: The invention relates to the preparation of multilayer microcomponents which comprise one or more films, each consisting of a material M selected from metals, metal alloys, glasses, ceramics and glass-ceramics. The method consists in depositing on a substrate one or more films of an ink P, and one or more films of an ink M, each film being deposited in a predefined pattern selected according to the structure of the microcomponent, each film of ink P and each film of ink M being at least partially consolidated before deposition of the next film; effecting a total consolidation of the films of ink M partially consolidated after their deposition, to convert them to films of material M; totally or partially removing the material of each of the films of ink P. An ink P consists of a thermoset resin containing a mineral filler or a mixture comprising a mineral filler and an organic binder. An ink M consists of a mineral material precursor of the material M and an organic binder.

Abstract: A process for production of a flexible laminated sheet having one or more laminated bodies each provided with a metal foil formed on one side of a resin film. The process includes coating a varnish containing a polyamic acid and a solvent onto the metal foil, holding the coated film, drying in which at least a portion of the solvent in the varnish is removed to form a layer composed of a resin composition, and forming the resin in which the layer composed of the resin composition is heated to form a resin film containing a polyimide resin. The conditions for each step from the coating up to the resin film-forming are adjusted based on a target for the content of metal elements in the resin film.

Abstract: A flexure 11 has a substrate 13 made of a thin conductive metal plate, a base insulating layer 31 made of flexible resin formed on the substrate, wiring patterns 15 formed on the base insulating layer and connected to a slider mount 17, and a cover insulating layer 33 formed over the wiring patterns. The flexure 11 is substantially coated with a conductive polymer layer 39 having a thickness in the range of 18 to 130 nm. The flexure 11 prevents electrostatic accumulation and ion migration that are trade-offs.

Abstract: The present invention generally relates to a resin composition, a cured resin, a sheet-like cured resin, a laminated body, a prepreg, electronic parts, single and multilayer circuit boards comprising a cyanate ester polymer and condensed phosphate ester, for use in single and multilayer circuit boards that are especially useful in the high-frequency range of above 100 MHz.

Abstract: Provided is a curable resin composition which exhibits improved developability even in through holes and can suppress the generation of development residue and which can yield a cured product with excellent heat resistance and hardness. A curable resin composition which comprises a carboxyl-containing resin, a photopolymerization initiator, and barium sulfate that has been pretreated with a dispersant having an acid group and/or a dispersant having a block copolymer structure, a graft polymer structure, and/or a star polymer structure.

Abstract: The invention is directed to a paste composition used for forming an electrode or wiring, wherein it comprises a) a conductive powder; b) a cellulose binder; c) an acrylate monomer; d) a radical polymerization initiator; and e) a solvent, and it is curable at a low temperature when compared to the prior paste compositions and it has excellent hardness, electrical resistivity and stability so that it can be usefully used for forming an electrode or wiring for a solar cell, RFID (Radio Frequency Identification) or PCB (Printed Circuit Board).

Abstract: Novel materials with thermally reversible curing mechanisms are provided. These inventive compositions are useful in forming microelectronic structures, such as dual damascene structures. The compositions comprise a crosslinkable polymer dispersed or dissolved in a solvent system with a crosslinking agent. In use, the compositions are applied to a substrate and crosslinked. Additional layers may be applied on top of the cured layer followed by additional processing steps. Upon exposure to a temperature above the crosslinking temperature of the composition, the cured layer will undergo a decrosslinking reaction to render the layer soluble in common photoresist solvents, including solvents used to make the composition itself. Thus, after processing, the remaining material can be dissolved away without damaging the substrate. The inventive materials are especially suited for processes involving low-k dielectric substrates.

Abstract: A composition for producing a printed circuit board is provided. The composition includes a polyamic acid having one or two crosslinkable functional groups introduced at one or both ends thereof, a liquid crystal polymer (LCP) or a liquid crystalline thermoset (LCT) oligomer, and an organic solvent. Therefore, the composition can be used as a material for next-generation boards that are becoming gradually lighter in weight and smaller in thickness and size. Further provided is a printed circuit board produced using the composition.

Abstract: An electrical component including a substrate comprising an electroconductive filler in a first polymeric binder, and a coating layer adhered to at least a portion of the substrate surface, the coating layer comprising a nanostructured electroconductive particulate dispersed in a polymeric binder, such as an epoxy resin. A method of making the component also is described.

Abstract: An object of the present invention is to provide (i) a polyimide precursor composition which is curable at a low temperature (not more than 250° C.) and which has a low viscosity despite having a high concentration, and a production method thereof, (ii) a polyimide coating film obtained from the polyimide precursor composition and having good properties, and a production method thereof, (iii) a photosensitive resin composition prepared by use of the polyimide precursor composition, and a production method thereof. The object of the present invention can be attained by a polyimide precursor composition containing an imidized tetracarboxylic acid having a specific structure and an isocyanate compound having a specific structure, or optionally a diamine.

Abstract: The present invention generally relates to a resin composition, a cured resin, a sheet-like cured resin, a laminated body, a prepreg, electronic parts, single and multilayer circuit boards comprising a cyanate ester polymer and condensed phosphate ester, for use in single and multilayer circuit boards that are especially useful in the high-frequency range of above 100 MHz.

Abstract: A composition that may be used to form an electronic circuit element includes metal nanoparticles in a metal nanoparticle solution, at least a low-polarity additive and a solvent. The low-polarity additive is either a styrenated terpene resin or a polyterpene resin. The composition may be used to form conductive features on a substrate by depositing the composition onto a substrate, and heating the deposited composition on the substrate to a temperature from about 80° C. to about 200° C. to form conductive features on the substrate.

Abstract: Self-metallizing polyimide films are created by doping polyamic acid solutions with metallic ions and solubilizing agents. Upon creating a film, the film is exposed to coherent light for a specific time and then cured. The resulting film has been found to have a metallic surface layer and a metallic subsurface layer (interlayer). The layer separating the metallic layer has a uniform dispersion of small metal particulates within the polymer. The layer below the interlayer has larger metal particulates uniformly distributed within the polymer. By varying the intensity or time of exposure to the coherent light, three-dimensional control of metal formation within the film is provided.

Abstract: A process for the production of an entry sheet for drilling a printed wiring board material, which process comprises forming a multi-layered water-soluble resin composition layer on at least one surface of a metal foil, wherein an aqueous solution of a water-soluble resin composition is applied to the metal foil, dried and solidified to form one water-soluble resin composition layer, the application, drying and solidification of the aqueous solution of the water-soluble resin composition are repeated at least once to form at least one water-soluble resin composition layer on the above one water-soluble resin composition layer, the multi-layered water-soluble resin composition layer is composed of these water-soluble resin composition layers, the multi-layered water-soluble resin composition layer has a thickness of at least 50 ?m and is almost free from air bubbles, and an entry sheet for drilling a printed wiring board material obtained by the above process.

Abstract: Disclosed is a resin composition, which comprises a thermosetting resin contained therein in an amount of 40 volume % or more, and a wax contained therein in an amount of 5 to 30 volume %, wherein: the thermosetting resin exists in liquid form at room temperature; and the wax exists in powder form at room temperature and has a melting point of 70 to 150° C., and wherein the resin composition has a viscosity of 50000 to 150000 mPa·s as measured at room temperature.

Abstract: Described are methods of making an electronic device, such as an RFID tag, including fabricating an antenna by depositing an electrically conductive polymer onto a substrate. The electrically conductive polymer is electrically connected to an electronic component, such as an IC chip or a diode. The electronic component may be placed on the substrate before or after the electrically conductive polymer is deposited. Once deposited, the electrically conductive polymer is cured. The electrically conductive polymer may be deposited in a number of ways, such using a mask having a desired pattern and applying the electrically conductive polymer to the mask, by screen printing the electrically conductive polymer or by printing the electrically conductive polymer using ink jet printing techniques.

Abstract: A polymer cures by either radiation or moisture curing mechanisms, or both. The polymer is prepared by hydrosilylation. The polymer includes units of formula: (R22Si02/2)b, (R2Si03/2)c, (SiO4/2)d, (R1?)f, and (R23Si01/2)g, where each R1 is independently an oxygen atom or a divalent hydrocarbon group; each R1? is independently divalent hydrocarbon group; each R2 is independently a monovalent organic group that is free of terminal aliphatic unsaturation each X is independently a monovalent hydrolyzable group; each J is independently a monovalent epoxy functional organic group; subscript a has a value of 1 or more; subscript b has a value of 0 or more; subscript c has a value of 0 or more; subscript d has a value of 0 or more; subscript e has a value of 1 or more; subscript f has a value of 0 or more; subscript g has a value of 0 or more; subscript s is 1, 2, or 3; and subscript t is 1, 2, or 3.

Abstract: An object of the present invention is to provide a polyimide precursor composition that can be cured at low temperatures (250° C. or lower), while having a low viscosity even at a high concentration, and a method of producing the same. Another object of the present invention is to provide a polyimide coating film obtained from the polyimide precursor composition and having good physical properties, and a method of producing the same. Furthermore, another object of the present invention is to provide a photosensitive resin composition containing the polyimide precursor composition, and a method of producing the same. These objects can be achieved by the polyimide precursor composition containing an imidized tetracarboxylic acid having a specific structure and a diamine having a specific structure.

Abstract: The present invention provides a substrate applicable in a chip LED package, the substrate having a conductive layer, an insulation layer and a heat-dissipation plate in this order, wherein the insulation layer comprises a liquid crystal polyester soluble in a solvent and a sheet comprising inorganic fibers and/or organic fibers. The substrate has a small linear expansion coefficient of the insulation layer in the surface direction and is extremely useful for production of a chip LED package while having a practical heat resistance.

Abstract: An electrical component includes a conductive substrate, a tin layer formed on the substrate, and a barrier coating formed on the tin layer to impede tin whisker growth. The barrier coating includes a polymer matrix, and abrasive particles that are dispersed about the matrix.

Abstract: An aqueous printable electrical conductor (APEC) is defined as a dispersion comprising metal powder (with specific surface properties) dispersed into an aqueous acrylic, styrene/acrylic, urethane/acrylic, natural polymers vehicle (gelatine, soy protein, casein, starch or similar) or in a film forming reactive fatty acids mixture without a binder resin. The aqueous printable dispersion can be applied to substrates through different printing processes such as flexography, gravure, screen, dry offset or others. Exemplary substrates include: (1) coated paper, (2) uncoated paper, and (3) a variety of plastics with treated and untreated surfaces. When printed at a thickness of 1-8 ?m, heating to cure is not required as the dispersion cures at ambient temperatures.

Abstract: The present invention concerns a process for the preparation of a silicone coating of low dielectric constant, comprising the following essential steps: a) a film-forming silicone composition is deposited on the surface of a substrate, said silicone composition comprising: (i) at least one crosslinkable film-forming silicone resin, (ii) at least one ?,?-hydroxylated, essentially linear silicone oil capable of degrading under the action of heat, and (iii) at least one solvent capable of rendering the silicone resin (i) compatible with the silicone oil (ii), b) the solvent (iii) is removed, preferably by heating, and, simultaneously or sequentially, c) the film-forming silicone composition is cured by heating. The invention deals also with a silicone coating obtained by this process and an integrated circuit comprising such a silicone coating as an electrical insulator.

Abstract: The invention is directed to a method by exposing at least a portion of a luminescent coating disposed on a surface of an article to ultraviolet light at one or more preselected wavelengths causing said luminescent coating to exhibit a luminescence spectrum, the luminescence spectrum exhibiting a plurality of intensity peaks that have been priorly determined to create a standard; determining the intensity of at least two peaks in the luminescence spectrum of the coating; determining a peak intensity ratio of the at least two peaks; comparing the peak intensity ratio determined with the standard; and, classifying the article according to whether or not the peak intensity ratio does or does not match the standard; wherein the luminescent coating comprises a particulate luminescent composition comprising a rare earth doped fluoride represented by the formula RExA1?xF2+x?2yOy wherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002?x?0.20, and 0?y?x.