International Business Machines Corporation

Russell W Boehm

Robert P Rippstein

Herbert Rees

David R Stone

Rex A Guinn

William R Keelen

Hans J Koerner

A family of circuit boards are molded, each board having its own unique pattern of recessed circuit paths and component insertion through-holes. A different mold is provided for each different member of the family. The two cavity blocks of each mold cavity contain only the holes that are necessary to define the through-hole pattern for that member of the family. A plurality of core pins or wires are provided at the molding site. Only the core pins that are required by the mold in use at the molding site are rendered operative. Features of the method and apparatus, in addition to this core pin insertion feature, include (1) the molding site includes a base member that is usable with all molds of the family, and has means for injecting molding material and means for ejecting a finished circuit board, the injection means and the ejecting means being located in the board's scrap edge area, (2) a hot runner injection system, (3) the mold cavity is placed under a partial vacuum prior to injection, (4) a semiconductor device is selectively used to rapidly heat or cool the mold, and (5) robot means, air and vacuum aids in ejection of a circuit board.

Method and apparatus for the injection molding of circuit boards

Sensor arranged to detect the proper placement and quantity of one or more inserts in the cavity of an injection molding machine. The sensor is preferably formed of a spring-biased plunger through one of the cavity shells. A photodetector monitors the movement of the plunger as the cavity-forming shells are closed and activates an alarm signal if the plunger movement is excessive before detection of proper mold closure.

Mold protection device

The complete, two-color, multiple keybutton array of a keyboard is molded by a two-shot injection molding method which uses a rotating, double female die means selectively cooperating with two male dies. The finished keybutton array is ejected to a carrier which then cooperates with a gathering fixture, which fixture is then movably adjusted to place the keybuttons in position for assembly to the keyboard.

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Longmont, CO, United States of America

Russell W Boehm