Using the ODB++ data format ensures PCB
manufacturers have all needed information in a single,
Once a circuit design is complete and the PCB
has been laid out, the complex process of transferring all the
design data to manufacturing begins. The data communicate not only
the physical positions of components, traces, and layers, but also
the intent. On top of this is manufacturing data: where to drill,
what to mask, and how to apply the board stencil.
For decades this data exchange has required a
lot of different files, each containing a part of the final
picture, somewhat like a jigsaw puzzle. These files include Gerber
data with the physical layout of the PCB; Excellon drill data;
netlists; and many others as needed.
After receiving this set of files, the PCB
fabricator or assembler must put the puzzle back together, perform
a time-consuming verification process to determine if all the
necessary files are there to produce the PCB, and determine if the
data are correct. Because the process has a lot of manual input,
human errors often creep into the information. Fabricators estimate
that about one-quarter of all Gerber file sets received have
Intelligent data format
The better way to transfer data is to have an
intelligent data format from the outset. Since ODB++ was first
introduced in 1995, it has been implemented by PCB design and
manufacturing organizations both large and small, globally. ODB++
format output is available on virtually all major CAD/CAM tools.
Although not a formal standard, it has been accepted to the point
of being a de facto standard,
adopted by many top-tier electronics manufacturers for many years
already. It was created and maintained by Valor Computerized
Products. When Mentor Graphics acquired Valor, Mentor re-pledged
continuing support for maintaining and advancing the ODB++ format.
Recently formed, the ODB++ Solutions Alliance (www.odb-sa.com) provides a forum
for implementers and supporters of the ODB++ format to share their
interest and success with others.
The ODB++ format
The ODB++ format is an open ASCII file structure
containing all product data for fabrication, assembly, and test in
a single file, including DFM analysis (see Fig. 1). Because of design and data
quality checks, the ODB++ file does not need the rigorous
examination by the fabricator. Minimizing the amount of manual
manipulation and packaging required data together ensures high
quality and quick turnaround.
Fig. 1: ODB++: One file for fabrication,
assembly, and test.
In addition to the usual set of information
conveyed in ODB++, many attributes can be communicated as well, and
automatically. Attributes such as impedance, plugged vias, surface
finish, and others can be included and automatically read and
understood by the fabricator. Users can also assign user-defined
attributes of characteristics to easily communicate this
information both internally and to suppliers that have been chosen
to receive the definition of the attribute.
While a great deal of product design information
is contained in the ODB++ file sent to the fabricator, there is no
risk of disclosing important IP. ODB++ can carry net names, inner
layer information, and component data up to the level that the user
feels appropriate for transmission into manufacturing, according to
how the CAD or DFM tool is configured to create and manage the
data. The intention of ODB++ is to give all necessary information
to manufacturing in an intelligent and integrated data-structure,
enabling the most efficient manufacturing.
Advantages are great
The significant advantages and automation
abilities associated with the ODB++ format make it the clear choice
for manufacturing data transfer in the future. Fewer errors mean
less expense, fewer re-spins, and quicker turnaround on PCB
fabrication, assembly, and test. The integrated DFM data helps
ensure that board assembly will proceed without any glitches to
send the process back to design. The future of PCBs includes ODB++.