AMD sued over patent

Individual files in California

Updated One of our readers seems to have turned up trumps over a legal action being taken against AMD over alleged patent violation. According to the reader, the patent in question (see original story below) is to do with a method for testing semiconductors during their manufacture. He points to this entry at at the US Patent Office which has the following abstract. "The present invention is generally related to a method and apparatus for accurately measuring the temperature of a surface and more particularly for the detection of hot spots on the surface of a semiconductor device due to fault-generated heat dissipation. "Liquid crystal materials have been used with particular benefit by designers and failure analysts of integrated circuits and other semiconductor devices. The liquid crystal material is applied to the surface of the semiconductor device and forms a nondestructive layer on the surface of the semiconductor which can be used to detect areas of high thermal dissipation by the semiconductor. These areas of high thermal dissipation can indicate areas on the semiconductor device which have failed or otherwise generate abnormal amounts of heat energy." And what a great lot our readers are. He explains: "Semiconductors are manufactured in layers. In order to monitor the process, there are several electrical tests done in line. Most processes will certainly do an e-test right after the creation of the transistors, and most likely at least after laying down the first metal layer. "Your e-test machine uses a "Wafer Prober" hooked up to an electrical tester. The tester provides the proper signals down the probers connectors, and energises the specific circuits being tested. The whole piece of equipment is topped by a multi-power microscope. "If you coat your wafers with "Liquid Crystal Display" film, and energise the circuits, any "Hot Spots" (ie: malfunctions) might cause the liquid crystal display film to "toggle" to black, and voila.... you could visually see it with the scope. It's an interesting technique, if you can set the film to the proper threshold to toggle." 21 December 1999: original story Chip company AMD is being sued over alleged patent infringement in the US. The case, filed against AMD by an individual, Peng Tan, was made earlier this month in the US district court in San Francisco. The case has been referred to Magistrate Judge Joseph C. Spero for his adjudication, under this statute. No details of which patent is in question were available, and AMD was unable to comment on the case at press time. When we receive details of which specific patent is allegedly infringed, we will update this story. ®

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