As many of you know, we now perform a design rule check on our Quick Turn multilayer orders. This was started sometime after the PCBexpress line began and although this information does not appear on the PCBexpress website, the DRC is performed on those orders as well. The process of running a DRC on our Quick Turn (Sunstone and PCBexpress) multilayer orders is a rather new procedure and if you are placing a reorder, may not have been performed on your files when the original order was processed.
This procedure was implemented after finding that internal layers regularly lacked the necessary clearance to prevent internal shorts. We are confident that this new information will be of help to you and the new procedure will help ensure that you continue to receive the highest quality circuit boards from Sunstone Circuits.
Sometimes the terminology that is used can be different between software products, designers, and pcb board shops and can be quiet confusing. Please see attached image Insufficient Clearance Issue_Image.jpg, and review information below about this image. I hope to explain a little about it and what we hope to achieve by sending the information to you or your designer.
The first (1.) sentence is just to inform the designer that there are inner layer clearances too small to accommodate the hole size and could result in shorting.
The Chart lists the tool number & size in question, the current clearance size and what our recommended clearance (size) is for that particular hole. Our recommendation is the size we guarantee that we can manufacture without the risk of shorts, as long as other design rules are maintained. See example attached: Clearance Size.jpg. You may notice that our recommended clearance size is larger than the current clearance size used; our recommendation here is that the clearance be increased to this size to accommodate the hole(s) in these locations.
The second (2.) sentence is the link to our drill/clearance chart on our website (Sample attached: Drill Chart Sample.jpg). The chart lists all Quick Turn preset tool sizes, pad and/or clearance size needed for each tool size.
As always, if you have questions about the email that you receive you may reply to the email with questions or call our Customer Service Team.
I hope this information helps!
If you have any questions, feedback, or suggestions about this post or any others you may reply here or contact us by phone. As always, we will do our best to assist you!