A method of forming a colloidal wetting sensitizer is disclosed. The method comprises combining a stannous species and a cupric species in an aqueous medium maintained at a pH of between 0.4 and 1.5.

A method of forming a colloidal wetting sensitizer is disclosed. The method comprises combining a stannous species and a cupric species in an aqueous medium maintained at a pH of between 0.4 and 1.5.

A continuous length, flexible, polymeric substrate has thin layers of copper clad to opposite sides thereof. Patterns of dry photopolymer material are applied to and mask selected portions of the copper to leave exposed other selected portions of the copper. The copper clad substrate is guided by a series of cathodic electrode rollers exterior of a copper plating bath into successive passes through the bath. Portions of the exposed copper contact the electrode rollers and couple the cathodic pot...

Prior to the production of microlenses (29) by the reactive ion etch technique, a pattern of notches (25) is formed in a second surface of a substrate (11) opposite a first surface on which the microlenses (29) are to be formed. Reactive ion etching of the first surface to produce the microlenses is sufficiently deep to reach the pattern of notches, thereby to separate the substrate. The array of notches may define, for example, an array of first areas (26) on the second surface, each area being...

An optical waveguide is made by forming successively of light transmitting material a first clad layer (13), a core layer (15) and a second clad layer (18). The core layer has a higher refractive index than that of the first and second clad layers such that the core layer (15) can transmit light along its length as an optical waveguide. A sacrificial layer (14, 17) is formed surrounding at least a first end potion of the core layer. The sacrificial layer is selectively removed as by selective et...

A method of removing contaminants from the surface is disclosed. The method comprises coating the surface with a surface active agent having a first surface energy and into which the contaminants are combined, applying thereover a higher surface energy colloidal sol and then allowing sufficient time for the first surface energy material with the contaminants combined therewith to migrate through the colloidal sol so as to remove the contaminants from the immediate vicinity of the substrate surfa...

A selective metallization process particularly suited for making printed circuit boards comprises the step of treating a substrate having a negative mask thereon with a reactant, e.g., acetic acid, which modifies the surface of the mask without affecting the substrate so as to remove or prevent an active catalytic layer from remaining on the surface of the mask thereby preventing electroless plating on the mask.

A method of selectively depositing a metal on a surface is disclosed. The method comprises selectively coating a surface with a surface active agent, having a first surface energy, to form a coated surface having a coated portion capable of burying a higher surface energy material applied thereto and an uncoated surface pattern not so capable. The selectively coated surface is then treated with a solution, having a second surface energy higher than the first, comprising a species selected from t...

A resilient and deformable touch screen that is adapted to be overlaid on the surface of a CRT screen is formed from a semi-rigid plastic frame attached to a flexible plastic pouch filled with a soft resilient material which adheres to the surface of the pouch.

A Langmuir-Blodgett monolayer polyimide film and a bulk amorphous polyimide film are in contacting superposed relation to form a composite film having improved moisture resistance. The composite film may be either a free film or provide an insulating coating on the surface of a microelectronics device.