Tape-out
Encyclopedia
In electronics design, tape-out or tapeout is the final result of the design cycle
for integrated circuit
s or printed circuit board
s, the point at which the artwork for the photomask
of a circuit is sent for manufacture.
The roots of the term can be traced back to the early days of printed circuit design, when the enlarged (for higher precision) "artwork" for the photomask
was manually "taped out" using black line tape and adhesive-backed die cut elements on sheets of PET film
. Subsequently the artwork was photographically reduced. A similar process was used for early integrated circuits.
The term tapeout currently is used to describe the creation of the photomask itself from the final approved electronic CAD file. This stage is sometimes referred to as PG, for Pattern Generation. Designers may use this term to refer to the writing of the final file to disk or CD and its subsequent transmission to the foundry; however, in current practice the foundry will perform checks and make modifications to the mask design specific to the manufacturing process before actual tapeout. Optical proximity correction
is an example of such an advanced mask modification; it corrects for the wave-like behavior of light when etching the nano scale features of the most modern integrated circuits.
A modern IC has to go through a long and complex design process before it is ready for tape-out. Many of the steps along the way utilize software tools collectively known as electronic design automation
(EDA). The design must then go through a series of verification steps collectively known as "signoff
" before it can be taped-out. Tape-out is usually a cause for celebration by everyone who worked on the project, followed by trepidation awaiting the first article
, the first physical samples of a chip from the manufacturing facility (semiconductor foundry).
First tapeout is rarely the end of work for the design team. Most chips will go through a set of spins where fixes are implemented after testing the first article. Many different factors can cause a spin, including:
Systems Development Life Cycle
The systems development life cycle , or software development life cycle in systems engineering, information systems and software engineering, is a process of creating or altering information systems, and the models and methodologies that people use to develop these systems.In software engineering...
for integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
s or printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
s, the point at which the artwork for the photomask
Photomask
A photomask is an opaque plate with holes or transparencies that allow light to shine through in a defined pattern. They are commonly used in photolithography.-Overview:...
of a circuit is sent for manufacture.
The roots of the term can be traced back to the early days of printed circuit design, when the enlarged (for higher precision) "artwork" for the photomask
Photomask
A photomask is an opaque plate with holes or transparencies that allow light to shine through in a defined pattern. They are commonly used in photolithography.-Overview:...
was manually "taped out" using black line tape and adhesive-backed die cut elements on sheets of PET film
PET film (biaxially oriented)
BoPET is a polyester film made from stretched polyethylene terephthalate and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties and electrical insulation.A variety of companies manufacture boPET and other...
. Subsequently the artwork was photographically reduced. A similar process was used for early integrated circuits.
The term tapeout currently is used to describe the creation of the photomask itself from the final approved electronic CAD file. This stage is sometimes referred to as PG, for Pattern Generation. Designers may use this term to refer to the writing of the final file to disk or CD and its subsequent transmission to the foundry; however, in current practice the foundry will perform checks and make modifications to the mask design specific to the manufacturing process before actual tapeout. Optical proximity correction
Optical proximity correction
Optical proximity correction is a photolithography enhancement technique commonly used to compensate for image errors due to diffraction or process effects...
is an example of such an advanced mask modification; it corrects for the wave-like behavior of light when etching the nano scale features of the most modern integrated circuits.
A modern IC has to go through a long and complex design process before it is ready for tape-out. Many of the steps along the way utilize software tools collectively known as electronic design automation
Electronic design automation
Electronic design automation is a category of software tools for designing electronic systems such as printed circuit boards and integrated circuits...
(EDA). The design must then go through a series of verification steps collectively known as "signoff
Signoff (electronic design automation)
In the automated design of integrated circuits, signoff checks is the collective name given to a series of verification steps that must pass before the design can be taped out...
" before it can be taped-out. Tape-out is usually a cause for celebration by everyone who worked on the project, followed by trepidation awaiting the first article
Prototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...
, the first physical samples of a chip from the manufacturing facility (semiconductor foundry).
First tapeout is rarely the end of work for the design team. Most chips will go through a set of spins where fixes are implemented after testing the first article. Many different factors can cause a spin, including:
- The taped-out design fails final checks at the foundry due to problems manufacturing the design itself.
- The design is successfully fabricated, but the first article fails functionality tests.