Radiation curable resin layer
AssigneeLexmark International, Inc.
InventorsGirish S. Patil, Brian C. Hart
Life of this patent
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Abstract
A radiation curable resin formulation suitable for planarizing an ink jet heater chip. The resin formulation includes a multifunctional epoxy component, a difunctional epoxy component, a silane coupling agent, an aryl sulfonium salt photoinitiator, and a non-photoreactive solvent. The resin formulation is substantially devoid of acrylate polymer components. Radiation curable resins according to the invention exhibit enhanced adhesion with the nozzle plate adhesive thereby reducing the incidence of delamination between the nozzle plate and a semiconductor chip containing the resin layer. Another advantage is that the resin layer, according to the invention, reduces pigment flocculation on the surface of the resin layer when using pigment-based ink jet inks.
Claims20
A radiation curable resin formulation suitable for planarizing an ink jet heater chip with a thickness ranging from about 1 to about 5 microns, the resin formulation consisting essentially of a multifunctional epoxy component, a difunctional epoxy component having a weight average molecular weight above about 2500, a silane coupling agent, an aryl sulfonium salt photoinitiator, and a non-photoreactive solvent, wherein the resin formulation is substantially devoid of acrylate polymer components and the resin formulation contains from about 60 to about 85 weight percent of the difunctional epoxy component and from about 12 to about 22 weight percent of the photoinitiator based on the weight of the cured resin.
A method for making an ink jet pen for an ink jet printer comprising applying a resin layer containing radiation curable resin formulation to a surface of a semiconductor chip containing resistive and conductive layers on the surface thereof to provide a cured resin layer having a thickness ranging from about 1 to about 5 microns, the radiation curable resin formulation including a multifunctional epoxy component, a difunctional epoxy component having a weight average molecular weight above about 2500, a silane coupling agent, an aryl sulfonium salt photoinitiator, a non-photoreactive solvent, and the resin formulation being substantially devoid of acrylate polymer components, removing solvent from the resin layer, curing the resin layer by exposure to actinic radiation to provide a cured resin layer, aligning and attaching a nozzle plate to the semiconductor chip with an adhesive to provide a nozzle plate/chip assembly, and attaching a TAB circuit or flexible circuit to the nozzle pate/chip assembly, wherein the cured resin layer contains from about 60 to about 85 weight percent of the difunctional epoxy component and from about 12 to about 22 weight percent of the photoinitiator.
A printhead for an ink jet printer which comprises a cartridge body containing one or more pens attached thereto, each pen including a nozzle plate, a semiconductor chip having a device surface attached to the nozzle plate, a flexible circuit or TAB circuit attached to the semiconductor chip and a radiation cured resin layer having a thickness ranging from about 1 to about 5 microns applied to the device surface of the semiconductor chip in order to planarize the surface of the chip, the radiation cured resin layer being derived from a radiation curable resin formulation containing a multifumctional epoxy component, a difunctional epoxy component having a weight average molecular weight above about 2500, a silane coupling agent, a non-photoreactive solvent, and an aryl sulfonium salt photoinitiator, wherein the resin formulation is substantially devoid of acrylate polymer components and the cured resin layer contains from about 60 to about 85 weight percent of the difunctional epoxy component and from about 12 to about 22 weight percent of the photoinitiator.
Dependencies are inferred from the claim text.