Hi, I've been going over a patch submitted to pcb by Wojciech Kazubski that supplies several additions to the QFP family of footprints.
I would like to incorporate these changes, but would like to discuss some naming conventions here first. One goal I have is to make sure what ever decisions are reached make it into the symbol document in gEDA as well as the geda library in PCB. I think this is crucial for making things easier on everyone who is using these tools. The basic issue is that the current document just has names like QFP80 QFP100 see http://www.geda.seul.org/docs/20030525/symbols/node14.html for the line which says: * Quad-side flat pack SMT are called QFPn. Unfortunately this doesn't quite cover what packages exist. For example, looking at an older National Semiconductor packaging databook, I see National package VHG80A is a square 12mm x 12mm QFP80 with 0.5 mm pin pitch National package VJE80A is a square 14mm x 14mm QFP80 with 0.65 mm pin pitch National package VCC80A is a rectangular 14mm x 20mm QFP80 with 0.8 mm pin pitch As another example, Analog Devices has a LQFP64 with 0.4 mm pin pitch where a LQFP100 offered by Dallas Semiconductor has a 0.5 mm pin pitch. The footprints provided by Wojciech use the following convention: QFPn_R is an 'n' pin rectangular QFP. Examples are QFP80_R which corresponds to the National VCC80A mentioned above. QFPn_x is a 'x' mm x 'x' mm square QFP with 'n' pins. LQFPn_x is a 'x' mm x 'x' mm square LQFP with 'n' pins. As an example, a LQFP80_12 is a 12mm x 12mm 80 pin LQFP like the National VHG80A mentioned above and a LQFP80_14 is a 14mm x 14mm 80 pin LQFP like the National VJE80A mentioned above. Does this seem reasonable to everyone? If so, I'll add the PCB footprints and submit a patch to the gEDA symbol document. On this topic can someone shed some light on the difference between QFP, TQFP, and LQFP? The QFP part is Quad Flat Package, but I'm not sure about the T and L. Thanks for your help and attention. -Dan --
