Abstract: A system is provided for measuring transmission characteristics of a gas of interest through a barrier material wherein a sealed test gas chamber is provided on one side of the barrier material and an aligned sealed measurement chamber is provided on the opposite side of the barrier material. A rough vacuum is pulled in the test gas chamber and a high vacuum pulled in the measurement chamber to establish a set pressure differential therebetween. A mass spectrometer having partial gas sensitivities of 5×10−4 Torr or lower in fluid communication with the measurement chamber determines permeation of the test gas of interest through the barrier material.

Abstract: A system is provided for measuring transmission characteristics of a gas of interest through a barrier material wherein a sealed test gas chamber is provided on one side of the barrier material and an aligned sealed measurement chamber is provided on the opposite side of the barrier material. A rough vacuum is pulled in the test gas chamber and a high vacuum pulled in the measurement chamber to establish a set pressure differential therebetween. A mass spectrometer having partial gas sensitivities of 5×10−4 Torr or lower in fluid communication with the measurement chamber determines permeation of the test gas of interest through the barrier material.

Abstract: Apparatus for vacuum pumping an enclosed chamber includes a cryopump in gas communication with the chamber for removing gases by cryocondensation and cryotrapping and an auxiliary pumping device for removing gases that are difficult to remove by cryocondensation or cryotrapping. The cryopump does not contain a sorbent material for cryosorption. As a result, the potential for contamination by a sorbent material is eliminated. The auxiliary pumping device can comprise an ion pump or a turbomolecular vacuum pump. When an ion pump is used, the ion pump is inactivated during periods of high gas loading in the chamber. The vacuum pumping apparatus is particularly useful for vacuum pumping of a plasma vapor deposition chamber.

Abstract: A plasma reactor includes a plurality of series of parallel disposed cylindrical electrodes carried in a common vacuum vessel chamber. The series of electrodes are adapted to provide alternate polarities on each side of a plurality of workpieces, such as printed circuit boards, enclosed in the reactor for treatment. Supporting brackets are provided for positioning the workpieces, parallel to and between planes formed by series of electrodes of alternate polarities. The supporting brackets are electrically isolated from the electrodes.

Abstract: A plasma reactor includes a series of parallel disposed electrodes carried in a vacuum vessel chamber. The series of electrodes is adapted to have alternate polarities. Supporting brackets are provided for positioning workpieces, such as multilayer printed circuit boards, parallel to and between electrodes of alternate polarities. The supporting brackets are electrically isolated from the electrodes. Furthermore, a uniform gas flow is directed across the surfaces of the workpieces upon their being subjected to a gas discharge plasma, by providing the plasma reactor with a parabolically-shaped door defining a parabolic surface within the vacuum vessel chamber, as well as vertically disposed baffle plates and at least three radial gas inlets located equidistantly about said chamber. The radial gas inlets have discharge ends directed at the parabolic surface of the door and are located between the baffle plates and the parabolic door surface.