A novel method of making continuous laminates by irradiation of a continuous sandwich of a radiation curable substrate and a metal foil is described. The method is especially useful for use in conjunction with substrates such as polyethylene in flexible printed circuit applications.
A method of embedding semiconductor components in plastics comprising inserting components into the plastics material and thereafter hardening the plastics material by irradiation with high energy beams.
A laminate is made of textile sheet structures of synthetic fibers or glass fibers with a covering of polypropylene. The polypropylene is crosslinked by addition of crosslinking agents. The laminate has good electrical insulating properties, perfect solder bath stability, and good mechanical machinability. This laminate is provided, in heated presses, with metal layers or can be provided, in heated presses, with metal layers or can be provided with such metals layers by the application of metallic foils or by electrolytical methods, and serves for the manufacture of printed circuits and ribbon cables. An advantageous production of the textile sheet structures encased with crosslinked polypropylene can be performed on roll stands by thermoplastic encasing and smoothing in a continuous process.
Flexible printed circuits and methods of fabricating and forming plated thru-holes therein are disclosed. The flexible printed circuits have one or more substantially rigid regions where plated thru-holes are to be formed, the regions being made rigid by the substitution of epoxy glass or other conventional rigid printed circuit board materials in place of the flexible material used for the flexible portions of the circuit. In this manner the thru-holes are formed through conventional printed circuit board layers, allowing plating of the thru-holes using conventional well developed techniques. This process avoids the necessity of plating thru-holes in flexible printed circuit materials currently requiring special equipment and techniques, and further avoids stress concentration at the junction between the rigid plated thru-holes and the adjacent flexible printed circuit. Various methods for forming such circuits and circuits so formed are disclosed.
An article of manufacture and method for assisting the lamination of printed circuits in a flat bed press, in which a stratiform sheet has a thermoplastic layer, a polymeric release layer on one side, a polymeric stabilizing layer having a melting point higher than the laminating temperature peak on the other side, both bonded to the middle thermoplastic layer which has a glass transition point lower than the laminating temperature peak, and a melting point higher than the peak, and the sheet is characterized by substantial freedom from creases, trapped gases, and contaminants between the layers, and the improved method using the stratiform sheet in a flat bed press operation.
A timer for controlling an appliance includes a housing. The timer also includes a camstack having a plurality of cam surfaces defined therein. The plurality of cam surfaces are positioned within the housing. The timer further includes a switch block which cooperates with the plurality of cam surfaces to provide switching operations for the appliance. Moreover, the timer includes an auxiliary member having a circuit pattern positioned on a side thereof. Rotation of the camstack causes rotation of the auxiliary member. The auxiliary member is positioned outside of the housing. The timer yet further includes a first switch arm positioned in contact with the side of the auxiliary member. Rotation of the auxiliary member causes the circuit pattern to be advanced into contact with the first switch arm. A method of controlling an appliance is also disclosed.