BOSTON -- Several data formats have vied for market acceptance through the five decades of computer-based electronics design. Here is a short list of the formats, their origins and current status.
Dynamic Process Format (DPF)
Ucamco’s (formerly Barco ETS) JOB database structure, which represent layer information of PCBs. Describes imageof the layer (pads, traces, holes, power and ground planes), electrical netlist information, and attributes.Version 7 released in March 2009.
Electronic Design Interchange Format (EDIF)
Originated in 1983. Was founded by a mixture of EDA companies (Daisy Systems, Mentor Graphics), OEMs (Motorola, National Semiconductor, Tektronix, Texas Instruments) and academia (University of California). A vendor neutral format for netlists and schematics. Its final release, 4 0 0, came in 1996, and the committee behind it has been dissolved.
Originated by Gerber Scientific as a means to describe information sent to its photoplotters. Has been updated several times, and by several companies (Barco, Ucamco). Gerber was a subset of the now-defunct Electronic Industries Alliance (EIA) RS-274-D specification. Includes:
- RS-274-D. Originated in the 1960s as a machine-based format (specifically for vector photoplotters). A subset of EIA RS-274-D specification, a format designed for mechanical numerical control (NC) machines in a wide range of industries. Is ASCII-based. Was limited to certain machines and was not considered a good format for PCB design data transfer as it did not describe apertures. Is now obsolete.
- RS-274X Gerber (Extended Gerber or X-Gerber). A 2D bi-level vector image description format. It is ASCII-based and vendor neutral. RS-274X is the de facto standard image description format for PCB manufacturing. However, it lacks precise netlist information.
Conceived under auspices of IPC in 1997. Also known as the IPC-2510 series. Original standard based on GenCAD format, which was donated to IPC by GenRAD Inc. in 1996. Designed as a replacement for IPC-D-350 and Gerber. Was developed with heavy involvement from the National Standards Institute and Technology (NIST), which wrote the Linux-based test conformance package. Original release was 1998; version 1.5 was released in 2000. Version 2.0 was released in February 2002.
Originated in 1970s. Described electronics design data from schematic through test files, using a series of standards numbered IPC-D-350 through IPC-D-356. Is vendor neutral and considered to be the first of the “intelligent” data transfer formats. Despite occasional bursts of effort through the years to update and popularize the IPC-D-350 series, only IPC-D-356 has been commonly used.
Originally labeled “Offspring,” because it was patterned after GenCAM. Was first released in 2004. Describes entire circuit board from schematic to parts list to board assembly and test. Is XML based. Is currently being updated for an “A” revision, which could be released in late 2011.
Created as ODB (Open Data Base) in 1995 by Valor Computerized Systems. Designed as a printed circuit board manufacturing machine language format for Valor’s Genesis CAM tools. Component descriptions were added in 1997, then Bills of Materials and AVL information in 1999. An XML-based format called ODB++(X) was released in 2000, but discontinued in 2008. Unlike other formats, whose translators are typically written by third-parties, Valor/Mentor maintains control over the translators and interfaces. Is used primarily by printed circuit board fabricators. In 2010, Valor was acquired by Mentor Graphics, which is continuing work on the standard.
Originated in 2001. Was revised in 2008. Covers electronic assembly interconnect and packaging design. Is an offshoot of EDIF 4 0 0, except for schematics.
1960s-1970s: The Beginning
Racal-Redac, one of the first CAD tool providers, was founded in 1965. As the industry sprung up around it, Racal-Redac (now Zuken) in 1970 released as series of tools for designing PCB schematic, silicon layout and routing. In 1974, Scientific Calculations introduced SciCards, and within the next few years, a slew of small software companies had arrived on the scene. IPC, under the direction of technical director Dieter Bergman, developed IPC-D-350 as a means to describe the full complement of design data, from bare board schematics, artwork and documentation to the component descriptions and test files.
On August 27, 1980, Gerber Systems published its first edition of Gerber Format: a Subset of EIA RS-274-D; Plot Data Format Reference Book. At the time, the format was still used for photoplotters.
By 1984, Mentor Graphics, Accel, P-CAD and Electronics Workbench had entered the scene. In late 1983, a group of EDA companies including Daisy and Mentor, OEMs (Motorola, National Semiconductor, Tektronix, TI) and the University of California-Berkeley formed a working group to develop EDIF. EDIF 1 0 0 was released in 1985, and version 2 0 0, was published in March 1988.
In 1986, Gerber was extended to support apertures of variable sizes.
The 1990s were characterized by several competing formats, including the introduction of ODB (later ODB++). In 1993, Gerber updated its Gerber Format: a Subset of EIA RS-274-D, Plot Data Format Reference Book. Also in 1993, EDIF 3 0 0 was released.
In 1995, Valor released ODB. In 1996, EDIF 4 0 0 was released, including Printed Circuit Board extensions.
In 1997 Barco Graphics acquired Gerber Systems, and began its own updates to the standard. In 1998, Barco released RS-274X.
In the late 1990s, as a result of the US government’ desire to advance the state-of-the-art in neutral product data standards, NIST became involved with the IPC effort, now labeled GenCAM. http://eislab.gatech.edu/projects/genx/description.html
In 1998, IPC released GenCAM 1.0.
In 2000, IPC released GenCAM version 1.5 in 2000. At that time, IPC announced a moratorium on updates until December 2001 to give software vendors time to validate and incorporate GenCAM into their tools.
In Fall 2000, Mentor and Valor announced a bidirectional interface between Mentor's Board Station layout suite and and Valor's Enterprise 3000 DFM software, the first such interface between PCB design tools and manufacturing analysis software.
In 2002, Barco was acquired by Mania Technologie. That same year, IPC released IPC-2511B, also known as GenCAM 2.0, and the first in its series to be XML-based.
Later in 2002, IPC technical director Dieter Bergman and Valor president Chuck Feingold agreed to a series of meetings under the auspices of the International Electronics Manufacturing Initiative (iNEMI). IPC and Valor agreed to submit their XML-based data exchange formats, then called GenCAMX and ODB++(X), to an iNEMI committee for the purpose of convergence into a single XML-based industry standard.
The committee set the following goals and objectives:
- Eliminate the use of Gerber and related old, non-intelligent formats for data exchange.
- Unite IPC/NEMI/Valor behind a single Industry standard for data exchange.
- Make the new standard XML compliant.
- Combine the best of both ODB++(X) from Valor and GenCAMX from IPC.
- Focus on providing solutions as well as standards.
- Formalize the converged standard using ANSI (American National Standards Institute) procedures.
Under the agreement, both sides ceased updates on their respective formats long enough for the iNEMI committee to make its decision. Valor agreed to donate its ODB++(X) format to the industry as a baseline for future efforts. Ultimately, the two parties went their own ways, but much of the public tension between the two groups quieted down.
In 2004, a new IPC task group was formed, and it released IPC-2581, which covers much of the same ground as IPC-D-350, only with current descriptions and an XML schema.
In August 2008, Mania and Barco were bought by ESO Capital Group and renamed Ucamco.
In March 2009, Ucamco released DFP version 7.
In December 2010, Ucamco released the RS-274X Format User's Guide, revision G.
In June 2011, IPC began work on IPC-2581A. It was published in May 2012.
In October 2013, IPC published IPC-2581B.
In December 2013, Ucamco released Gerber X2, a version of Gerber that includes attributes for describing non-image data.
In 2014, at the urging of some of its main PCB fabricator customers, Frontline decided to add IPC-2581 as an output to its Genesis 2000 software.
In late 2015, Mentor Graphics joined the IPC-2581 Consortium.
In early 2016, Fujitsu and its partners built a 20-layer PCB using only IPC-2581B data. Ericsson and
Ed: Also see the following related items: