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US 6,190,823 B1Granted
Diazo-containing photosensitive material
AssigneeSomar Corporation
InventorsYoko Suzukawa, Nobue Abiko, Hiroshi Maruyama
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AssigneeSomar Corporation
InventorsYoko Suzukawa, Nobue Abiko, Hiroshi Maruyama
Estimating the term…
A diazo-containing photosensitive material comprising a transparent support, and a diazo-containing photosensitive layer provided over a surface of the support and containing a binder, a diazo compound and a coupler, wherein the diazo compound is represented by the following formula: (wherein R1 and R2 stand, independently from each other, for a lower alkyl group and X stands for an anionic group), wherein the coupler comprises phenylphenol and 3,5-dihydroxy-4-bromobenzoic acid, and wherein the binder comprises a cellulose ester cross-linked with a lower-alkylated urea resin.
A diazo-containing photosensitive material comprising a transparent support, and a diazo-containing photosensitive layer provided over a surface of said support and comprising a binder, a diazo compound and a coupler,
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Compositions containing diazo compounds as photosensitive substances: coupling substances therefor
Photosensitive materials: compositions containing diazo compounds as photosensitive substances
Compositions containing diazo compounds as photosensitive substances: diazonium salts or diazo anhydrides
Photosensitive materials for photographic purposes
Term ended 9 Jun 2020 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to a diazo-containing photosensitive material useful for the fabrication of photomasks.
It is known to use a photosensitive material having a transparent film on which a diazo-containing photosensitive layer capable of affording a light-shielding colored image as a photomask for the fabrication of printed wiring boards and various printing plates.
In the fabrication of a printed wiring board, a photosensitive resin layer is formed over a conductive layer such as a copper clad laminate. A photomask is superimposed on the photosensitive resin layer. Then, the photosensitive resin layer is exposed through the photomask using a contact printing device. The exposed photosensitive resin layer is developed to form a pattern. The conductive layer is then etched according to the pattern. The remaining photosensitive layer is thereafter removed to give a desired wiring pattern. The contact printing step has a great influence upon resolution of images and working efficiency in the production of printing wiring boards. In particular, when the photomask is not closely contacted with the photosensitive resin layer, Newton rings and air entrainment occur to cause cutting or distortion of wiring patterns. Thus, it is necessary to evacuate air between the photomask and the photosensitive resin layer for a long period of time in order to obtain good contact therebetween.
One side of a polyester film having a thickness of 175 μm is applied with a coating liquid having the formulation shown below with a wire bar. The coated layer was dried at 100° C. for 3 minutes to obtain a diazo-containing photosensitive film having a photosensitive layer with a thickness of 10 μm.
Coating Liquid Methyl ethyl ketone 37 parts by weight Propylene glycol monomethyl ether 37 parts by weight Synthetic silica 0.4 part by weight (average diameter: 3.5 μm) Cellulose acetate propionate 12 parts by weight Butylated urea resin 8 parts by weight (solid matter content: 60 wt %) p-Toluenesulfonic acid (hydrate) 0.4 part by weight Sulfosalicylic acid 0.2 part by weight Thiourea 0.4 part by weight Zinc chloride 0.4 part by weight o-Phenylphenol 2.0 parts by weight Coupler of the formula (II) 0.2 part by weight Diazo compound of the formula (I) 2.0 parts by weight (in which R1 and R2 are CH3 and X is PF6)
The above butylated urea resin is a solution containing 60% by weight of solid matters and is sold by Mitsui Chemical Corporation under a trade name “UVAN 10S60”.