Tom Dlouhy, C.I.D.
CAD Design Software
San Jose, California 95110


ABSTRACT

In the early days of PCB design/layout, a rough design drawing was done on paper or mylar and the circuitry transferred to “taped” mylar or rubylith, which was done at a 2X, 4X or some other scale and then photo-reduced to a 1:1 scale. While this sufficed for simple designs of the day, future designs would only become more complex and more confined. The photo-reductions lacked the accuracy required for drastically reduced trace widths and spaces. This process could be quite costly, resulting in initial designs and design changes having to be carefully checked and re-checked prior to getting photo-reductions processed.

Time and technology proved there was a better way and Electronic Design Automation (EDA) software started to become common place. The early EDA software was only geared toward digital PCB layout while specialty technologies such as RF/Microwave were left with no specialty design features. As a stopgap measure, many RF/Microwave designers turned to using CAD software and translators to either design at 1:1 and achieve direct result photo-plot image films or import the design file into their corporate EDA software. Many times the importation process of the design file into the EDA software was itself problem prone with data being lost.

While this eliminated the photo-reduction process of the circuitry images and its costs and inherent problems, it still did nothing to achieve what the digital PCB design/layout world was taking advantage of; this being schematic capture, LVS (layout vs. schematic), and DRC (design rule checking). Still the RF/Microwave and specialty technology PCB industries trudged on with manual node checking usually involving at least 2 people simultaneously, one to read the schematic or node list and one to check the layout design. DRC was also done manually and this usually involved an additional third person, so that another set of eyes was checking the design.

As the PCB and specialty PCB industries moves into the future, requirements for schematic capture, checking, embedded components and elements, 3D, etc. will continue to grow in the continuing quest for smaller, more complex, and in many cases more powerful designs, as well as new manufacturing and assembly processes. These required features of PCB design are needed to dramatically reduce or eliminate the problems experienced in current designs and to help fit the design in the required real estate on the board.

In order to dramatically improve reliability, yields, and substantially decrease costs and design-time-to-product for the PCB specialty technologies, a true design process including 3D is required which integrates the design, optimization, verification, manufacturing, and assembly processes into a seamless system. This 3D design and collaboration system provides data access by all related departments in order to optimize the design for maximum performance as well as highest yield and fastest time-to-product. Manufacturing, engineering, and assembly departments are able to input specific 3D design and manufacturing parameters during the design/layout process. The design/layout is completed and assembly parameters are verified and optimized in 3D during the design process. The resultant design has already been optimized for manufacturing when it arrives in production, thereby eliminating many of the problems prone in the design and assembly process today.

This paper explains the origins, role and benefits of advanced EDA tools in PCB specialty technologies.
(HF, RF, 3D, CAD, EDA, Design, Layout, Collaboration, Processes)

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