What is the cost of an integrated circuit with these conditions? Wafer is a 10 inches diameter circle. A wafer cost 10,000 bahts Each die is 4 mm x 4 mm Yield is 90% What will be the cost if yield is only 60%? Wafer area = pi x (5x2.54)^2 = 506 sq mm die area = 4 x 4 = 16 sq mm dies per wafer = 506/16 = 31 cost of a die = 10000/(31x0.9) = 358 bahts if yield 60% then cost of a die = 10000/(31x0.6) = 555 let us explore defect number Let Defect per area is 1 defect per 20 square mm. die area = 16 sq mm. yield = 1/(1+(0.05x16/2))^2 = 51%