Schaltungsplatte mit mehreren Leiterebenen und Verfahren zu ihrer Herstellung

摘要

A circuit board, which has at least two conducting layers separated by interposed insulating layers, having electrical connections through an opening in the insulator layer characterized by the connection having surface-to-surface bond between the conducting layers with a portion of at least one conducting layer deformed into an opening of the separating insulating layer. The circuit board is formed by superimposing a plurality of layers into a stack with the insulating layers between adjacent conducting metal layers. Then heat and pressure are applied to the stack of superimposed layers to force the conducting layers into surface-to-surface engagement and form the bonding of the connection. In the preferred embodiments a filler material such as a metal or metal alloy having a low melting point is provided preferably as a small area coatings on the conducting layers in a pattern corresponding to the pattern of the connections. Complex circuit boards having a large number of conducting layers, can be formed by first forming a core in accordance with the invention and then interposing the core between additional insulating and conducting layers and repeating the heating and pressing step.