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Miller Design and Equipment - New and Used Refurbished Equipment for the Semi-conductor Industry
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Choosing A Manual/Analytical Probe Station
Options and Considerations
Chuck Size (wafer size) 4 to 8 with any custom size, shape or vacuum pattern Vacuum chucks can be provided in various finishes (gold, nickel or stainless) Gold is probably the most common for backside wafer contact.
X&Y Manual Stage Travel: 4, 5 6 or 8 Usually stage travel is the same as chuck size, but can be larger. Some systems have motorized drives to speed travel. All systems provide adequate precision movement for positioning to a probe card or microscope viewing.
MicroscopesMitutoyo Highest cost (turret style nose piece, 2:1 internal zoom) Motic Very similar to the Mitutoyo, less expensive. B&L Microzoom (medium cost but limited availability, no longer manufactured, 2:1 internal zoom) Single Tube (Navitar or Optem), Internal zoom 6x-7x (medium cost) used with CCD camera and monitor up to 1000x magnification, very good working distance. Ergonomically more comfortable than stereo models. Stereo Zoom 4x 5x long working distance, lowest cost, but only 60x-100x magnification All probers use long working distance (LWD) microscopes. Magnification requirement is based upon size of bond pads/line widths or targets. Wide field of view is needed when large die with many pads requires view showing that all probes are properly placed (X-Y microscope stages are also available, allowing user to move microscope) Turret Style Scopes (rotating nose piece with 3 or 4 objectives) provide a large range of magnification, but can interfere with probes. Internal Zoom Stereo scopes have good working distance and various magnification capabilities (50x-1000x) Single Tube Microscopes have excellent working distance and allow many users to view wafer or sample at same time on a monitor, also ergonomically sound as you are not bent over eyepieces. Can also use additional objectives, thus giving a wide range of magnification
Over-All Size (footprint) Probers that move the vacuum chuck between the platen instead of traveling under it, have the largest footprint as wafer sizes increase or grow. Choice of B&L Microscope and Mitutoyo/Motic (turret style) have a large 3-1/2 x 4 focus block. This adds to the Y dimension of the probe station footprint.
Platens & Probe Card Holders Platens where XYZ Micropositioners are placed are usually plated steel for magnetic or vacuum based Positioners. Almost all probe stations can be fitted with standard 4-1//2 wide probe card holders.
Probe Positioners (Micropositioners) XYZ Movement A variety of manufacturers, with style mainly determined by position relationship of the chuck height to the platen. Where the chuck height and platen are roughly similar a straight probe holder is used. When the chuck is below the platen height, a drop down probe holder is needed. A few probe stations, like some Micromanipulator models, have the chuck above the platen, so probe holders need to have some vertical rise on the holders.
Probes/Needles Many manufacturers of probe styles are providing single needle DC probes, co-axial probe and arm combinations or RF style probes. Needles are also varied in shank diameter, length and tip style and diameter. (Probes and needles do not come with probe stations, too many choices and variables)
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Last modified: 05/06/09 |