Friday, December 09th
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designThe PCB manufacturing process is complex.  The precision of the manufactured PCBs hinges on many things, but none more important than accurate and complete manufacturing or design data, most often Gerber files.  A wide variety of PCB design software applications are used to produce manufacturing data, and the complexity of each design can vary significantly.  As a result, the manufacturing data generated may not always yield the intended results, leading to board failures, manufacturing delays and increased costs.

In our third and final post in this 3-part series (miss Part 1 or Part 2?) we address a few of the more complex issues that we encounter with Gerber files and how to avoid them.

 

Gerber File Problem 7 – Vector Fills

Often plane layers or layers with shield areas are provided to us filled with 1 mil or 2 mil vectors. This causes the Gerber file to be quite large in size and requires a process to “contourize” the data. When we panelize this type of data, the files often become too large for the plotter (equipment) to digest. It is recommended that for areas to be filled, use “raster” or “contour” data.

Gerber File Problem 8 – Composite Layers

Some PCB design software uses composite layers to create one layer. For example, a plane layer with embedded traces will use three layers just to create one layer; first, you have the plane layer, then the clearance layer, then the trace layer. Some layers are positive images while others are negative images. Layers similar to this, should all be combined then output as a single Gerber layer.

Gerber File Problem 9 – Vectorized Pads

Some PCB design software creates surface mount pads with vectorized data, meaning the pad is composed of many small vectors arranged in such a manner as to create a surface mount pad. This requires the CAM operator to substitute all the surface mount pads to create one flash pad. This not only reduces the amount of data, but also helps in the editing of such files. Better to use flash pads if you can.

 

We trust you have found some helpful suggestions from this three-part series on Gerber file problems.  If you have further questions, our experienced team is available to assist on your next project.

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