Target Condition: Are Autorouters Friend or Foe?
Fresh PCB Concepts: Assembly Challenges with Micro Components and Standard Solder Mask Practices
Elementary Mr. Watson: Retro Routers vs. Modern Boards—The Silent Struggle on Your Screen
The Gerber Guide, Chapter 2
October 5, 2015 | Karel Tavernier, UcamcoEstimated reading time: 2 minutes
It is clearly possible to fabricate PCBs from the fabrication data sets currently being used; it's being done innumerable times every day all over the globe. But is it being done in an efficient, reliable, automated and standardized manner? At this moment in time, the honest answer is no, because there is plenty of room for improvement in the way in which PCB fabrication data is currently transferred from design to fabrication.
This is not about the Gerber format, which is used for more than 90% of the world's PCB production. There are very rarely problems with Gerber files themselves; they allow images to be transferred without a hitch. In fact the Gerber format is part of the solution, given that it is the most reliable option in this field. The problems actually lie in which images are transferred, how the format is used and, more often, in how it is not used.
In this monthly series, I will explain in detail how to use the newly revised Gerber data format to communicate with your fabrication partners clearly and simply, using an unequivocal yet versatile language that enables you and them to get the very best out of your design data. Each month we’ll look at a different aspect of the design to fabrication data transfer process.
This column has been excerpted from the Guide to PCB Fabrication Data: Design to Fabrication Data Transfer.
Chapter 2: Alignment (Registration)
Never mirror or flip layers! All layers must be viewed from the top of the PCB, which means that the text must be readable on the top layer and mirrored on the bottom layer. Alas, sometimes, in a mistaken attempt to be helpful, designers flip layers because they must anyway be mirrored on the photoplotter. This could be helpful in a world where the designer's files are used directly in fabrication, but these data layers are actually input for the CAM system. This needs the correct 2.5D PC structure, so designers need to follow the standard protocol for providing digital data. The fabricator's CAM system will do the rest: it will optimise and panelise the PCB and on output of the final, panelised data, it will mirror, rotate, shift and scale as required by production. Any designer that mirrors layers can only hope that the CAM engineer notices this and ‘unmirrors’ them.
To read this entire article, which appeared in the September 2015 issue of The PCB Design Magazine, click here.
Share on:
Suggested Items
DownStream Acquisition Fits Siemens’ ‘Left-Shift’ Model
06/26/2025 | Andy Shaughnessy, I-Connect007I recently spoke to DownStream Technologies founder Joe Clark about the company’s acquisition by Siemens. We were later joined by A.J. Incorvaia, Siemens’ senior VP of electronic board systems. Joe discussed how he, Rick Almeida, and Ken Tepper launched the company in the months after 9/11 and how the acquisition came about. A.J. provides some background on the acquisition and explains why the companies’ tools are complementary.
Elementary Mr. Watson: Retro Routers vs. Modern Boards—The Silent Struggle on Your Screen
06/26/2025 | John Watson -- Column: Elementary, Mr. WatsonThere's a story about a young woman preparing a holiday ham. Before putting it in the pan, she cuts off the ends. When asked why, she shrugs and says, "That's how my mom always did it." She asks her mother, who gives the same answer. Eventually, the question reaches Grandma, who laughs and says, "Oh, I only cut the ends off because my pan was too small." This story is a powerful analogy for how many PCB designers approach routing today.
Connect the Dots: The Future of PCB Design and Manufacturing
07/02/2025 | Matt Stevenson -- Column: Connect the DotsFor some time, I have been discussing the increasing complexity of PCBs and how designers can address the constantly evolving design requirements associated with them. My book, "The Printed Circuit Designer’s Guide to… Designing for Reality," details best practices for creating manufacturable boards in a modern production environment.
Siemens Turbocharges Semiconductor and PCB Design Portfolio with Generative and Agentic AI
06/24/2025 | SiemensAt the 2025 Design Automation Conference, Siemens Digital Industries Software today unveiled its AI-enhanced toolset for the EDA design flow.
Cadence AI Autorouter May Transform the Landscape
06/19/2025 | Andy Shaughnessy, Design007 MagazinePatrick Davis, product management director with Cadence Design Systems, discusses advancements in autorouting technology, including AI. He emphasizes a holistic approach that enhances placement and power distribution before routing. He points out that younger engineers seem more likely to embrace autorouting, while the veteran designers are still wary of giving up too much control. Will AI help autorouters finally gain industry-wide acceptance?