In the first instance, I wouldn't leave it to the PCB manufacturer to add 'thieving' wherever he fancies. In certain circumstances he could inadvertently compromise circuit performance or safety. Take responsibility for this yourself. In answer to your specific question, it all depends on what you connect the 'thieving' to. If it is not connected to the circuit, then it is floating. If it is connected to 0V, then it is at 0V. You will need, of course, to ensure that you maintain clearances around the edges of this area. For EMC purposes, it can be advantageous to connect areas of 'thieving' or 'infill' to 0V, forming a ground plane, but in this instance it is best achieved by connecting the area to the 0V plane by vias at around 5mm (0.2")pitch. Also, >from an EMC perspective, it doesn't really matter whether the plane is 0V or a power plane, as both should be as good as ground at RF.
Best regards Neil R. Barker CEng MIEE FSEE MIEEE Manager Compliance Engineering e2v technologies (uk) ltd 106 Waterhouse Lane Chelmsford Essex CM1 2QU UK Tel: (+44) 1245 453616 Fax: (+44) 1245 453410 Mob: (+44) 7801 723735 From: Sylvia Toma [mailto:[email protected]] Sent: 17 November 2005 03:28 To: [email protected] Subject: Thieving on PCB Hello group, I have a question regarding thieving on printed circuit board and hoping that you could help me: If the PCB manufacturer wants to add copper thieving to the PCB layers to help balance the copper distribution since there is a potential for thickness variation as well as possible warp without it, is the copper thieving considered to be at '0' volt or treated as 'floating' as far as safety spacing is concern? Looking forward to your reply. Regards, Sylvia - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
