Desmear and etchback using NF.sub.3 /O.sub.2 gas mixtures
AssigneeAir Products and Chemicals, Inc.
InventorsJohn A. Barkanic, Donna M. Reynolds
Life of this patent
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Abstract
The present invention is directed to a method for plasma desmear and etchback of epoxy and polyimide materials from a multilayered or double sided printed circuit board using a plasma gas composition in the range of 20-45% NF.sub.3, the remainder being O.sub.2.
Claims6
In a method for desmearing printed circuit boards using a plasma gas desmearing medium produced between a pair of electrodes in an evacuated chamber wherein the material being desmeared is selected from the group consisting of epoxy and polyimide, the improvement comprising desmearing with a plasma comprising a gas mixture of 20-45% NF.sub.3 the remainder being O.sub.2 wherein the chamber is evacuated to a pressure in the range of 1000 to 3000 milli-Torr, and wherein the power density used to create the plasma is in the range of 0.08 to 0.25 wat/cm.sup.2.
Dependencies are inferred from the claim text.