18.104.22.168.1 ASIC Devices
The rapid technology changes in the field of microelectronics,
both hybrid and monolithic, have to be monitored closely. Application Specific
Integrated Circuits (ASICs) are one part type usually considered to be
critical. The advent of ASICs requires a change in the device selection
procedure. The term "ASIC" describes a wide variety of different types of
devices which can include custom and semicustom standard cells, gate arrays,
Programmable Logic Devices (PLD) and Field Programmable Gate Arrays (FPGA)
typically designed for a specific application. Advantages include a relatively
short development cycle and customized performance and functionality.
Disadvantages are that the equipment schedule may be impacted because system
designers are involved in the device design cycle, and unproven vendors and
technologies may be used for the first time.
Typically, ASIC devices are designed for a very specific
application and then produced and sold in very limited quantities. Thus, there
is no market for marginal devices. Historically, generic ICs have been
produced in a tiered market environment. Parts not meeting the highest level
of performance could usually be sold to a less demanding customer at a reduced
price. This is simply not the case with ASICs. Either they are 100% perfect or
they are scrap. Given this fact, there is a very strong incentive to reduce or
eliminate all possible variation in the part manufacturing processes to attain
a very high yield of good parts. Thus, Total Quality Management (TQM) and SPC
become imperative to the manufacture of these types of parts. To use ASICs, a
supplier must select and certify a silicon foundry and design the device using
foundry design rules. Performance would be demonstrated through simulation
tools. The foundry would then fabricate wafers and packaged devices for test.
The planning and management of ASIC design requires a very rigorous and
controlled procedure to achieve desired device functionality, reliability,
cost and delivery schedules.