Abstract: The invention is a hybrid chuck for securing workpieces with an electrostatic charge. The hybrid chuck includes a dielectric base for supporting the hybrid chuck. The dielectric base has a top surface and a conductive layer covers at least a portion of the top surface of the dielectric base. The conductive layer is conductive for receiving a current that creates an electrostatic charge and is non-metallic for maintaining the electrostatic charge without significant eddy current losses in the presence of dynamic electromagnetic fields. The top working surface covers the conductive layer and is flat for holding workpieces upon the receiving of the current to create the electrostatic charge in the conductive layer.

Abstract: The invention is a hybrid chuck for securing workpieces with an electrostatic charge. The hybrid chuck includes a dielectric base for supporting the hybrid chuck. The dielectric base has a top surface and a conductive layer covers at least a portion of the top surface of the dielectric base. The conductive layer is conductive for receiving a current that creates an electrostatic charge and is non-metallic for maintaining the electrostatic charge without significant eddy current losses in the presence of dynamic electromagnetic fields. The top working surface covers the conductive layer and is flat for holding workpieces upon the receiving of the current to create the electrostatic charge in the conductive layer.

Abstract: An improved positive control non-return valve assembly which is mounted on the front end of a helical plasticating screw of an injection molding machine. The valve assembly comprises a thread retainer with means for attachment to the plasticating screw. The valve assembly also comprises a distribution chamber that has an annular shaped flow gap and a cylindrical passageway that leads to a plurality of discharge ports. The non-return valve assembly forms a seal, builds pressure, and displaces molten plastic fluid from the distribution chamber through a discharge chamber passageway, and into a mold.

Abstract: An improved shoot-through warhead cover is constructed of a low density material, such as polyethylene foam, in a dome-like shape. An anterior surface of the shoot-through cover is configured so as to be in proximate mating relationship with the exterior surface of an EFP liner member. The exterior surface of the cover is also aerodynamically contoured to match the external shape of a receiving warhead delivery vehicle body.

Abstract: An electrostatic chuck is disclosed that is resistant to the formation of vacuum arcs between the back of the wafer being processed and the body of the chuck. A guard ring surrounds the chuck and floats close to the self-bias potential induced by the plasma on the wafer. The voltage between the wafer and the closest electrode is thereby capacitively divided by the guard ring.

Abstract: An electrostatic chuck has its electrodes biased with respect to the self-bias potential induced by the plasma on the wafer, thereby providing improved resistance to breakdown in spite of variation of the wafer potential during processing. An alternate embodiment further suppresses the formation of vacuum arcs between the back of the wafer being processed and the body of the chuck by the interposition of a conductive guard ring at the self-bias potential, thereby defining an equipotential area between the closest electrode and the wafer.

Abstract: An electrostatic chuck is made by a method in which the component parts are machined, then anodized to provide a hard insulating surface, and then assembled in a fixture, to provide a planar surface for wafer support that retains superior insulating properties; gas may be fed from the rim only, diffusing within interstices between the clamping surface and the wafer and maintaining a desired pressure by flowing radially through an impedance determined by the average spacing between clamping surface and wafer, thereby providing uniform pressure across the clamping surface without the use of elastomeric seals.

Abstract: An aluminum electrostatic chuck for holding semiconductor wafers during wafer processing. The chuck is characterized by a closely determined magnitude of electrostatic holding force due to an anodization step for creating a finely uniform thickness of dielectric material on the chuck surface facing the wafer which, in turn, determines the holding force. The chuck cross section comprises two different thickness areas with fluid cooling being applied to the thinner thickness area during chuck anodization to assure thickness uniformity of the anodized material across the face of the chuck.

Abstract: An electrostatic chuck has its electrodes biased with respect to the self-bias potential induced by the plasma on the wafer, thereby providing improved resistance to breakdown in spite of variation of the wafer potential during processing, further suppressing the formation of vacuum arcs between the back of the wafer being processed and the body of the chuck by the interposition of a conductive guard ring at the self-bias potential, thereby defining an equipotential area between the closest electrode and the wafer.

Abstract: An electrostatic chuck suppresses the formation of vacuum arcs between the back of the wafer being processed and the body of the chuck by the interposition of a guard ring that floats close to the self-bias potential induced by the plasma on the wafer, thereby capacitively dividing the voltage between the wafer and the closest electrode.

Abstract: An electrostatic chuck 8 assembly includes, from top to bottom: a top multilayer ceramic insulating layer 10; an electrostatic pattern layer 12 having a conductive electrostatic pattern 16 disposed on a multilayer ceramic substrate; a multilayer ceramic support layer 20; and, a heat sink base 30 having a backside cooling channels machined therein. Layers 12, 12 and 20 are bonded together using multilayer ceramic techniques and the heatsink base 30 is brazed to the bottom of the multilayer ceramic support layer 20.

Abstract: An electrostatic chuck 40 assembly includes, from top to bottom: a top isolation layer 42; an electrostatic pattern layer 44 comprised of an electrically conductive electrostatic pattern 46 disposed on a substrate 45; a heating layer 50 comprised of an electrically conductive heating pattern 54 disposed on a substrate 52; a support 60; and, a heat sink base 70 having backside cooling and insulating channels 78, 80 provided therein.

Abstract: An electrostatic chuck is provided with an electrode split into two sections. The separate sections are joined through a tapered joint and bonded using epoxy. An insulator electrically separates the two sections and covers the top of the joined sections to form a clamping surface. The geometry of the electrode forms three annular regions, dividing the clamping surface into two equal areas distributed symmetrically. Moreover, the split-ring electrostatic chuck just described is fabricated by forming the two, separate electrodes; coating the separate electrodes with an insulator; joining the electrodes; machining the joint, top surface of the electrodes to form a single, co-planar, flat, smooth surface; and applying an insulator to that top surface.

Abstract: An electrostatic chuck is provided with an electrode split into two sections. The separate sections are joined through a tapered joint and bonded using epoxy. An insulator electrically separates the two sections and covers the top of the joined sections to form a clamping surface. The geometry of the electrode forms three annular regions, dividing the clamping surface into two equal areas distributed symmetrically. Moreover, the split-ring electrostatic chuck just described is fabricated by forming the two, separate electrodes; coating the separate electrodes with an insulator; joining the electrodes; machining the joint, top surface of the electrodes to form a single, co-planar, flat, smooth surface; and applying an insulator to that top surface.

Abstract: A material tester which allows for material characterization under hydrodmic loading including very high rates of loading such as found in ballistic applications, and which includes various interchangeable fittings to allow the tester to simultaneously subject a test specimen to (1) radial compression and axial tension, or (2) radial compression and axial compression, or (3) radial compression and axial shearing stress.

Abstract: An electrostatic chuck has its electrodes biased with respect to the self-bias potential induced by the plasma on the wafer, thereby providing improved resistance to breakdown in spite of variation of the wafer potential during processing. An alternate embodiment further suppresses the formation of vacuum arcs between the back of the wafer being processed and the body of the chuck by the interposition of a conductive guard ring at the self-bias potential, thereby defining an equipotential area between the closest electrode and the wafer.

Abstract: An electrostatic chuck is disclosed that is resistant to the formation of vacuum arcs between the back of the wafer being processed and the body of the chuck. A guard ring surrounds the chuck and floats close to the self-bias potential induced by the plasma on the wafer. The voltage between the wafer and the closest electrode is thereby capacitively divided by the guard ring.