{"id":10078,"date":"2021-02-01T02:34:53","date_gmt":"2021-02-01T07:34:53","guid":{"rendered":"https:\/\/blogs.sw.siemens.com\/pcbflow\/?p=174"},"modified":"2026-03-27T09:45:30","modified_gmt":"2026-03-27T13:45:30","slug":"old-habits-die-hard","status":"publish","type":"post","link":"https:\/\/blogs.sw.siemens.com\/electronic-systems-design\/2021\/02\/01\/old-habits-die-hard\/","title":{"rendered":"Old Habits Die Hard"},"content":{"rendered":"\n

In one of my previous blog posts<\/a>, I asked the question: Why do designers keep sending Gerber files to their manufacturers, knowing that the manufacturers will have to work hard to restore information that is \u201clost in transition\u201d due to the format limitations? The typical answer was \u2013 and still is \u2013 that they believe that manufacturers can manage with Gerbers.  Why not? They\u2019ve been managing for decades!<\/p>\n\n\n\n

In this post, I will discuss another old habit of designers that won\u2019t die \u2013 putting non-copper features on copper layers, without considering the impact on manufacturing.<\/p>\n\n\n\n

Non-copper features on copper layers<\/h2>\n\n\n\n

Sounds like a no-brainer, right? Why would anyone put non-copper features on copper layers? Well, apparently, many designers do so without realizing that any <\/em>feature they put on a copper layer is considered to be copper and will be manufactured as such.<\/strong><\/p>\n\n\n\n

The simplest and most common example is the text box with common information about the board, the revision, layer, customer, etc. Most likely, there\u2019s no intention to print this information on the real board. But if these features are not deleted explicitly during the pre-production stage at a fab \u2013 they will be printed. In most cases, these features are easily recognizable by a manufacturer and thus, no questions need be asked \u2013 they are simply deleted. In some cases (when the text box is clearly located outside the board outline, and\/or when the board is exported as ODB++, and these features bear a proper attribute) they may even be automatically recognized by CAM software \u2013 making it even simpler.<\/p>\n\n\n\n

The next example is much less trivial, and more dangerous: lines that run along the board outline. In the below illustration, you can find lines that denote copper traces, as well as inner and outer cutouts \u2013 in the same layer \u2013 you, of course, can easily distinguish between them. So you most likely rely on your fabrication partner\u2019s CAM engineer to recognize them and to delete them before the layer data is sent to production, right?<\/p>\n\n\n\n

\"Copper<\/figure>\n\n\n\n

Recently, I had conversations with three very experienced layout designers working for different companies in different countries and different industries \u2013 but the dialog was very similar:<\/p>\n\n\n\n