Because the larger IC has X times more area than the smaller IC, it is X times more likely to have a failure. In actuality it is harder to get a GOOD large IC than a smaller IC. The unit cost goes up because you have to divide the cost of the waffer by a smaller number of good sensors. So if you have a 30% failure rate, you get 70 DX sensors $71, but only 28 FX sensors $179. The larger sensors will cost more per sensor. ![]() ![]() The DX sensor would be $50, and the FX sensor $125. Divide cost of $5,000 per waffer by the number of sensors per waffer. The waffer size is constant, so the larger the sensor, the less sensors can be made out of the waffer. If you can make 100 DX size senors out of one waffer, you may be able make only 40 FX size sensors. Numbers that follow is for illustration only, not actual production numbers, because I have no idea what the cost of a single waffer is, nor the current yield statistics. ![]() So each device costs more, given a fixed cost per waffer.Ģnd, in general, larger devices have a lower yield rate, because of defects. The larger the sensor the higher the cost.įirst, you obviously get less devices out of a single silicon waffer.
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