Encapsulating prismatic inductance - has fixing contact ends in off=centre split plane of mould and injecting resin asymmetrically to inductance

摘要

A prismatic encapsulated inductance for surface assembly is produced, consisting of a horizontal wound support body with contacts of flat metal on the ends; in the process the wound body is placed in an injection mould with non-central split plane and with a rectangular section; the space between the body and mould walls is then filled by injecting a liq. polymer in through at least two opposite nozzles. The contacts are rectangular, with their free ends attached parallel to but off-centre on the support body; their ends are located in the split line of the mould; the locations, times and torques of forces acting on the body while polymer is being injected are neutralised by choice of the injector positions, the masses of flowing polymer and their viscosities, so that the body is turned through not more than 5 deg. in the mould. The contacts are pref. attached by an epoxy adhesive, and the encapuslating material is pref. polyphenylenesulphide or a liquid crystal polymer. ADVANTAGE - The process can be carried out in short prodn. cycles in automatic plant. The encapsulation is suffiicent for wave soldering.