Patent attributes
A thin walled balloon formed in polymer tubing has a patterned metal layer on its outer surface, created by physical vapor deposition (PVD). The pattern is defined by a stencil mask assembled around the balloon, with the balloon inflated therein. The PVD occurs without deforming or degrading the polymer material of the balloon, by actively pulling heat away from the balloon a) by forming the stencil mask out of metal; b) by providing a metal heat conduction path away from the balloon to a heat sink, such as outside the vacuum chamber, and/or c) by flow of a cooling fluid within the balloon during the PVD process. Proper PVD process parameters are selected to minimize heat generation, such as having argon pressure in the range of 0.8 to 1.2 milli-torr and generating the plasma at a power of less than about 200 watts/ square inch of effective target surface area.
