As a PCB manufacturer, we receive hundreds of PCB layouts represented in Gerber format every week. As you might expect, they’re not all created equal. Some of the layouts check every box and roll straight into manufacturing, while others need work before they can be sent to the production floor.
We affectionately refer to these layouts on occasion as Etch-A-Sketch designs, meaning that they did not adhere to best practices nor pay close attention to detail during the layout phase. And yes, sometimes these designs really do look like they were created on a toy from the ‘70s and not in a CAD tool. We recognize there are many good reasons for not-quite-ready-for-prime time designs to be submitted, such as:
• A designer lacking layout experience
• Looming deadlines and rushed design processes
• A lack of attention to the details
• A need for something to test in a hurry
Often, these issues create delays and issues with yield or reliability. They can be avoided before they cause problems with your budget and production schedule. Here are some best practices for doing so. Use the Tools in Your CAD Program You can represent a feature in your design by almost any means you’d like, but adhering to a few best practices leveraging the many useful functions in your CAD design tools can help eliminate confusion for your PCB manufacturer. For example, you can represent slots as overlapping drilled holes in your design. It is a common practice, but it creates two potential issues for the manufacturer:
1. If left as is, it can create broken drill bits impacting yields and quality of the product.
2. The other possibility is that the tooler corrects the issue during manufacturing, which is a very inefficient process. Most software for PCB layout offers the capability to make a slot and have it contained on the drill layer of the Gerber files.
Most software for PCB layout offers the capability to make a slot and have it contained on the drill layer of the Gerber files.
To read this entire column, which appeared in the January 2020 issue of Design007 Magazine, click here.