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Obligatory rant: Chip Shots converts silicon wafer area units to metric, again |
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Nov 07, 2007 at 06:19 PM |
A recurring rant here at Chip Shots is the failure of the global semiconductor industry to convert the last remaining vestiges of English system measurements of wafer size and silicon area into metric units.
When otherwise metrically inclined people say "inches," I reply "arrggh!" One culprit is the SEMI Silicon Manufacturers Group (SMG), who continues to smugly avoid a metric reporting of its silicon wafer area shipment trends.
SMG's third-quarter numbers for shipments of test, epitaxial, nonpolished, and product semi wafers (but not compound semi or solar) were flat compared to the previous period, though up about 5% versus Q306. Volker Braetsch, Siltronic EVP and SMG chair, said earlier this week that the second-to-last quarter is traditionally a slower one on the silicon front. He then quickly left the metaphorical room after uttering the words "2174 million square inches," "2201 million square inches," and "2074 million square inches"---the stated amounts for Q307, Q207, and Q306, respectively---before the European metric police could arrest him.
So what were those silicon wafer area numbers again? That was 1,402,577 square meters for Q307, 1,419,997 square meters for Q207, and 1,338,061 square meters for Q306. Although individual wafers are measured in millimeters, those numbers get toooo large to use (unless one's bloated ego revels in the extra digits): for example, the Q307 figures run out to 1,402,577,840,000 (yup, trillion) square millimeters. But then, that is one of the joys of metric, with its sliding scale of perfectly segmented units.
Although there's still a contingent of folks who call the current largest wafers "12 inch," most have migrated to the metric 300 mm. But have you ever heard anyone refer to the next possible/likely wafer size as "18 inch"? It's always called "450 mm," full stop.
Again, the question needs to be asked: When is the industry going to convert its silicon measurements to metric once and for all?
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