Die size does not determine IC cost

摘要

Years ago, you could look at the size of a semiconductor die and make a good guess about the manufacturer's cost. This situation is no longer true, even if you understand that a fine-line CMOS process costs more than a 250-nm process and CMOS processes tend to cost less than bipolar or BiCMOS processes (Reference 1). Even if you know the cost of a chip's process, you still have no idea of the required test time—an important factor because test time is a major component of an IC's cost. Bob Reay, vice president and general manager of mixed-signal products at Linear Technology, points out that the company fabricates ADC chips with a ring of thick metallization around the periphery of the die. Linear runs large currents through this ring at test time.