Dennis On 0603 here, plucked randomly from a production board, Pad size (standard pb) is 1 x 1 mm with pads 1.7mm apart. Component pitch 1.6mm (gives gap of 0.6 mm aprox). Our Pb free size is different although this still works its not optimal.
These run through our process here of paste (using MPM3030 printers) and Philips (Assembleon/Yamaha) placement machines and Soltec oven just fine, including double sided reflow. The same boards are also made elsewhere using a mixture of Dek printer / Universal chip shooters/Panasonic placement/Soltec reflow ovens. What you will get away with regarding component pitch and densities will depend also on the reflow process as your paste definitions are closely linked to the reflow capabilities of the CEM. If you go pb free you will have a lot less reduction on pad size so the printer tolerances (or slowed down for repatability) so will need to be looked at, as you want to retain good gasketing to the pad even at high speed using very wet pastes so it does not weep in between the SM pads you could end up with some paste deposit in the trench which will solder ball who knows where.... I would expect some comments from your CEM with a 40 mil (1mm approx) pitch as this only leaves a gap of 0.2 mm between pads of 0.8 x 0.8 mm which will end up with no solder mask between them, since most 0603 (1608) parts have width of 0.8 mm +/- 0.15mm or so, if the max parts tolerances for physical size are seen in reality (0.15mm) on 2 parts side by side then this exceeds the available space between parts so they will touch. So placement accuracy does not even come into it as the physical dimensions of the parts leave no tolerance at all. 0603 resistor sizes and tolerances based on Rohm MCR03/Samsung RC1608, Cap sizes from Murata GRM18/Samsung CL10 series. Hope you find some of this useful, hopefully I did not make an error jumping between mils/mm :-) John > -----Original Message----- > From: Dennis Saputelli [mailto:[EMAIL PROTECTED] > Sent: 20 February 2005 18:43 > To: Protel EDA Discussion List > Subject: Re: [PEDA] how close 0603 > > > how close do y'all pack 0603's side by side ? > > Dennis Saputelli > > ______________________________________________________________ > _________ > Integrated Controls, Inc. Tel: 415-647-0480 EXT 107 > 2851 21st Street Fax: 415-647-3003 > San Francisco, CA 94110 www.integratedcontrolsinc.com > > > > > ____________________________________________________________ > You are subscribed to the PEDA discussion forum > > To Post messages: > mailto:[email protected] > > Unsubscribe and Other Options: > http://techservinc.com/mailman/listinfo/peda_techservinc.com > > Browse or Search Old Archives (2001-2004): > http://www.mail-archive.com/[email protected] > > Browse or Search Current Archives (2004-Current): > http://www.mail-archive.com/[email protected] > > ____________________________________________________________ You are subscribed to the PEDA discussion forum To Post messages: mailto:[email protected] Unsubscribe and Other Options: http://techservinc.com/mailman/listinfo/peda_techservinc.com Browse or Search Old Archives (2001-2004): http://www.mail-archive.com/[email protected] Browse or Search Current Archives (2004-Current): http://www.mail-archive.com/[email protected]
