Fine-tuning Semiconductor Production.Two linear motion elements redesigned to meet industry parameters Specialized machines for semiconductor industry tasks, ranging from wafer polishing to wire bonding Wire bonding is a method of making interconnections between a microchip and other electronics as part of semiconductor device fabrication. The wire is generally made up of one of the following:
Combating Crass-roller Cage Creep Issues As an example, precision rail guide systems with cross-rollers usually are employed in X/Y positioning applications where accuracy, high precision, and speed are essential. These assemblies can be found in wafer inspection and lithography lithography (lĭthŏg`rəfē), type of planographic or surface printing. It is distinguished from letterpress (relief) printing and from intaglio printing (in which the design is cut or etched into the plate). machines, metrology metrology Science of measurement. Measuring a quantity means establishing its ratio to another fixed quantity of the same kind, known as the unit of that kind of quantity. instruments for inspecting wafer flatness, wire bonding equipment, and in many other applications where multiple-axis positioning tables or stages come into play. Cross-roller systems are robust linear bearings with high load-carrying capability suitable for a wide range of linear bearing arrangements with limited travel. But end-users of these systems more often than not can attest To solemnly declare verbally or in writing that a particular document or testimony about an event is a true and accurate representation of the facts; to bear witness to. To formally certify by a signature that the signer has been present at the execution of a particular writing so as to a potentially persistent problem during a machine's nonstop HP's brand name for its fault-tolerant servers, which range in size from four CPUs to 4,000 CPUs. The NonStop line was created by Tandem Computers, which was acquired by Compaq, which later became part of HP. use: migration of the cage and roller assembly. This migration is so common that it has been dubbed dub 1 tr.v. dubbed, dub·bing, dubs 1. To tap lightly on the shoulder by way of conferring knighthood. 2. To honor with a new title or description. 3. by the industry as "cage creep." Cage creep can be especially noticeable when cross-roller systems are subjected to high speeds, high acceleration, uneven loads, and vertical orientations Vertical orientation is a 3:4 aspect ratio, rotated 90 degrees from a NTSC television's standard 4:3 aspect ratio. It has been used primarily for arcade games (especially during the early 1980s) and for art projects, including a music video by The Shamen. . In most cases, the system's cage gradually migrates toward one end of the travel. As the cage moves farther from its centered position, the system friction increases at the stroke limits. The cage then hits the end stops and causes the rollers to skid. The machine either has to be shut down for cage repositioning repositioning Laparoscopic surgery The changing of a Pt's position during a procedure to improve access or visualization of the operative field, which may be linked to complications, as it changes anatomic planes of operation. Cf Laparoscopic surgery. or it must be equipped with larger (and more costly) motors to deliver the necessary power to reset the cages. Designers have sought to reduce cage creep by incorporating wires and pulleys into assemblies, but these attempted solutions have achieved only limited success and have added unwanted costs and taken up premium space. The ultimate goal has been to eliminate cage creep altogether, and a patented Anti-Creep System (ACS (Asynchronous Communications Server) See network access server. ) has been designed to provide this capability. The ACS keeps the cage permanently centered within a cross-roller system and, as users in the semiconductor industry can attest, the cage does not migrate and never needs to be reset. In an industry where size and space matter, the ACS (which is an internal drop-in component) works easily within the design envelope of a standard cross-roller system, maintaining dimensional integrity of an assembly. Roller Screws with Fine Leads Another example of innovation in linear motion is the evolution of roller screws to meet specific performance requirements. Roller screws transfer the load from the nut to the screw shaft through a number of threaded or grooved rollers rather than balls. Their greater number of contact points enables a higher load-carrying capacity and a much longer life than similarly sized ball screws A ball screw is a mechanical device for translating rotational motion to linear motion. A threaded shaft provides a spiral raceway for ball bearings which act as a precision screw. (which also are bulkier due to larger diameters). But the industry "wish list" for roller screws has included a desire for even finer leads, which would promote high positioning accuracy, repeatability, and rigidity rigidity /ri·gid·i·ty/ (ri-jid´i-te) inflexibility or stiffness. clasp-knife rigidity . Designers have responded by developing recirculating roller screws (with grooved rollers), which feature unprecedentedly small leads (1mm). The design of these screws promotes fine resolution, minimum drive torque, and high mechanical advantage, to minimize input torque and increase resolution. The screws' roller contacts make assemblies simple, robust, and reliable, all in a relatively smaller package; and their many strong contact points contribute to heavy load-carrying capacity, high rigidity, and long life. These screws usually are specified for precision-positioning applications, such as wafer polishing and testing equipment, as well as for many other types of machines. |
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