E.i. Dupont De Nemours and Company

Cda Processing Limited Liability Company

E. I. Du Pont De Nemours

Thomas Eugene Dueber

Brian C Auman

Frank L Schadt, Iii

John Donald Summers

Kuppusamy Kanakarajan

William J Nebe

Michael W J West

Munirpallam Appadorai Subramanian

Albert Gordon Anderson

Robert Valentine Kasowski

Harry Richard Zwicker

Bruce M Monroe

Michael W West

Yueh-Ling Lee

Howard E Simmons

Joseph E Gervay

Paul James Martin

David H Scheiber

Richard A Wessel

Nyrissa S Rogado

Xin Fang

William J Link, Deceased

Xin Shane Fang

This invention relates to compositions, and the use of such compositions for protective coatings, particularly of electronic devices. The invention concerns fired-on-foil ceramic capacitors coated with a composite encapsulant and embedded in a printed wiring board.

Screen-printable encapsulants based on polyhydroxyamides that thermally convert to polybenzoxazoles

This disclosure relates to compositions and methods for using such compositions to provide protective coatings, particularly of electronic components. Fired-on-foil ceramic capacitors coated with a polybenzoxazole encapsulant which may be embedded in printed wiring boards are disclosed.

Screen-printable encapsulants based on soluble polybenzoxazoles

Water absorption resistant polyimide/epoxy-based compositions, like pastes (or solutions), are particularly useful to make electronic screen-printable materials and electronic components. A group of hydrophobic epoxies (and soluble polyimides) was discovered to be particularly resistant to moisture absorption. The polyimide/epoxy pastes made with these epoxies (and these polyimides) may optionally contain thermal crosslinking agents, adhesion promoting agents, blocked isocyanates, and other inorganic fillers. The polyimide/epoxy pastes of the present invention can have a glass transition temperature greater than 250&#xb0; C., a water absorption factor of less than 2%, and a positive solubility measurement.

Composition of polyimide and sterically-hindered hydrophobic epoxy

The present invention is directed to coverlay compositions derived from two-layer polyamic acid-based composites having a cover layer and adjacent thereto an adhesive layer wherein the cover layer comprises polyamic acid and other additives allowing the composition to be photosensitive and aqueous base developable, and where the adhesive layer can form a polyimide having a glass transition temperature between 170 and 250&#xb0; C. The two-layer coverlay compositions of the present invention are used to encapsulate metal circuit traces formed on a flexible printed circuit base substrate. These two-layer compositions are particularity useful due to having an overall in-plane CTE between 10 and 40 ppm/&#xb0; C. a range that is useful in avoiding unwanted curling of a flexible printed circuit when used as a polyimide-based coverlay material.

Polyimide composite coverlays and methods and compositions relating thereto

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&#xb0; C. and up to 200&#xb0; 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.

Low-temperature curable photosensitive compositions

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&#xb0; C., have a water absorption factor of less than 2%, and a have a positive solubility measurement.

Polyimide compositions having resistance to water sorption, and methods relating thereto

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&#xb0; 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&#xb0; C. and 250&#xb0; C.) that differ by more than 10, 15, 20 25, or 30 ppm/&#xb0; C.

Polyimide based adhesive compositions useful in flexible circuit applications, and compositions and methods relating thereto

A flexible, flame-retardant, aqueous processable, photoimageable resin composition for forming a permanent, protective coating film for printed circuitry and a multilayer photoimageable element containing a layer of the photoimageable resin composition in combination with a low tack photoimageable resin sublayer and a temporary support film are disclosed. The photoimageable resin composition has excellent aqueous developability and provides a cured coating film having good flexibility, adhesion, solvent resistance, surface hardness, thermal resistance, electrical insulating properties and flame retardancy.

Flexible, flame-retardant, aqueous-processable photoimageable composition for coating flexible printed circuits

Aqueous processable, photopolymerized coating compositions are disclosed, which after curing, have superior flexibility for use as permanent coatings for the protection of printed circuitry.

Flexible, aqueous processable, photoimageable permanent coatings for

An aqueous processable, photoimageable element for use as a permanent coating for the protection of printed circuits composed of multiple layers of photoimageable compositions has suffiently low tack to avoid premature adhesion to the printed circuit substrate but develops good adhesion to the circuit substrate upon application of heat and pressure during lamination.

Aqueous processable, multilayer, photoimageable permanent coatings for

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.

Pliable, aqueous processable, photopolymerizable permanent coating for

A method for inhibiting the formation of blisters during the firing of intermediate layers of fired multilayer electronic components comprising the sequential steps of:

Method for making porous bottom-layer dielectric composite structure

A photosensitive ceramic coating composition which is fireable in a substantially nonoxidizing atmosphere comprising an admixture of:

Photosensitive ceramic coating composition

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.

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Wilmington, DE, United States of America

Thomas Eugene Dueber