Abstract: The invention relates to low-temperature curable photosensitive compositions containing a polyamic acid, which compositions are developable in aqueous alkaline solutions and are curable, at a temperature of at least 160° C. and up to 200° C., to low modulus polyimides suitable for use in electronic circuitry applications, and which are particularly suitable for use in flexible circuit applications where low curl, low temperature curing, and good adhesion is a significant advantage.

Abstract: The invention relates to low-temperature curable photosensitive compositions containing a polyamic acid, which compositions are developable in aqueous alkaline solutions and are curable, at a temperature of at least 160° C. and up to 200° C., to low modulus polyimides suitable for use in electronic circuitry applications, and which are particularly suitable for use in flexible circuit applications where low curl, low temperature curing, and good adhesion is a significant advantage.

Abstract: Water absorption resistant polyimide pastes (or solutions), are particularly useful to make electronic screen printable pastes and the electronic components made from these pastes. A group of soluble polyimides and their solvents were discovered to be particularly resistant to moisture absorption. These polyimide solutions optionally contain polyimides also containing cross-linkable monomers and/or thermal cross-linking agents. In addition, these polyimide pastes may optionally contain adhesion promoting agents, blocked isocyanates, metals, metal oxides, and other inorganic fillers. The polyimide pastes (or solutions) of the present invention have a polyimide with a glass transition temperature greater than 250° C., have a water absorption factor of less than 2%, and a have a positive solubility measurement.

Abstract: Disclosed is an organic encapsulant composition that, when applied to formed-on-foil ceramic capacitors and embedded inside printed wiring boards, allows the capacitor to resist printed wiring board chemicals and survive accelerated life testing conducted under high humidity, elevated temperature and applied DC bias.

Abstract: Disclosed area compositions comprising: a polyimide resin with a water absorption of 2% or less and, optionally, one or more of an electrically insulated filler, a defoamer and a colorant and one or more organic solvents. The compositions are useful as encapsulants and have a consolidation temperature of 190° C. or less.

Abstract: The low modulus polyimide adhesive compositions of the present invention contain a low modulus polyimidosiloxane polymer, a thermosetting substantially-non-halogenated epoxy (optionally including an epoxy catalyst), a plasticizer, an insoluble halogen-free flame-retardant filler, and optionally an adhesion promoter. The adhesive can be applied upon (or incorporated into) flexible circuits using a relatively low lamination temperature, generally no higher than 200, 190, 180, 175, 170, 165, 160, 155, or 150° C. The adhesive is generally resistant to unwanted curl even in cases where the adhesive polyimide and the base film polyimide have a coefficient of linear thermal expansions (measured between 50° C. and 250° C.) that differ by more than 10, 15, 20 25, or 30 ppm/° C.

Abstract: A flexible, aqueous processible, photoimagable coverlay compositions, having advantageous adhesion and release properties and resistance to (unwanted) haloing. The coverlay compositions of the present invention comprise an acrylic, low Tg, graft copolymer binder component, having an alkali resistant backbone-segment and a pendant arm segment comprising hydrophilic moieties. Optionally, the coverlay further comprises a thiophene-type adhesion promoter to further improve adhesion properties.

Abstract: Aqueous processable photopolymerizable compositions containing (a) a cobinder system, (b) an acrylated urethane monomeric component; (c) a photoinitiator system; and (d) a thermal cross-linking agent are disclosed, which as cured compositions, are flexible and can be used as permanent coatings for the protection of printed circuitry.

Abstract: A method for inhibiting the formation of blisters during the firing of intermediate layers of fired multilayer electronic components comprising the sequential steps of:(1) applying to a substrate a first and second layer of finely divided particles of dielectric solids and glass dispersed in organic medium; and(2) firing the layers to effect volatilization of the organic medium therefrom, liquid phase sintering of the glass components and densification of both layers, the softening point of the glass, the particle size of the glass and the ratio of glass to dielectric solids in both layers being adjusted in such manner that when the layers are fired, the first layer is porous and the second layer is nonporous.

Abstract: A photosensitive ceramic coating composition which is fireable in a substantially nonoxidizing atmosphere comprising an admixture of:(a) finely divided particles of ceramic solids having a particularly defined surface area-to-weight ratio and particle size, and(b) finely divided particles of an inorganic binder having a particularly defined surface area-to-weight ratio and particle size, dispersed in an organic medium comprising(c) an organic polymeric binder and(d) a photoinitiation system, dissolved in(e) photohardenable monomer and(f) an volatile organic solvent.

Abstract: Photopolymerizable composition consisting essentially of (A) at least one ethylenically unsaturated monomeric compound, (B) at least one 2,4,5-triarylimidazolyl dimer, (C) sensitizing amount of at least one polymeric sensitizer, weight average molecular weight 10,000 to 300,000, which is the reaction product of (1) a reactive photosensitizer and (2) a reactive polymer as defined herein, and (D) optionally an organic polymeric binder. The compositions are useful in photoresists, chemical milling, toning films and printing plates.

Abstract: Photopolymerizable crystalline composition having a crystallinity index of at least 0.2 which comprises: (a) at least one ethylenically unsaturated monomer, (b) at least one photoinitiator, (c) at least one acidic polymeric binder and (d) a crystalline matrix forming compound having a melting point of 50.degree. to 200.degree. C. The compositions are useful in film form as photoresists, litho films, etc.

Abstract: Photopolymerizable compositions comprising(a) at least one ethylenically unsaturated compound,(b) at least one organic polymeric binder,(c) optionally at least one photoinitiator and(d) at least one constrained N-alkylamino aryl ketone compound as defined, e.g., bis(9-julolidyl ketone), bis-(N-ethyl-1,2,3,4-tetrahydro-6-quinolyl)ketone, etc. The compositions, in layer form, are useful in photoresists, including projection speed photoresists, printing plates, drafting and toning films, etc.

Abstract: Multilayer photosolubilizable litho element comprising (1) support, (2) photosolubilizable dye or pigment-containing layer having an optical density in the visible region of the spectrum of at least 2.0 comprising a quinone diazide and at least one acidic polymeric binder, and (3) photosolubilizable layer comprising a quinone diazide compound and at least two acidic polymeric binders having carboxylic acid substituents, one binder having an acid number below 110, preferably poly(methylmethacrylate/methacrylic acid). The element is useful as a single exposure positive contact litho film.

Abstract: A photopolymerizable coating composition comprising(1) a nongaseous, ethylenically unsaturated, polymerizable compound,(2) a specified acidic o-nitroaromatic compound, and(3) an organic, radiation-sensitive, free-radical generating system which is useful for making a positive or negative polymeric image on a substrate.

Abstract: Photopolymerizable compositions comprising (a) at least one ethylenically unsaturated compound, (b) at least one photoinitiator or photoinitiator system, (c) sensitizing amount of an N-alkylindolylidene or N-alkylbenzothiazolylidene alkanone as defined, and optionally (d) at least one organic polymeric binder. The compositions, in layer form are useful in printing plates, litho films, photoresists, solder mask and for making image proofs. The products show sensitization to visible light.

Abstract: This invention relates to new photopolymerizable compositions. More particularly, this invention pertains to photopolymerizable compositions containing photodissociable initiators in combination with selected sensitizers derived from aryl ketones and p-dialkylaminoarylaldehydes that absorb in the visible region of the spectrum.