Bert Timmerman wrote: > Hi Jelle, > > On Wed, 2009-05-13 at 14:45 +0200, Jelle de Jong wrote: >> Hello everybody, >> >> I am trying to create a footprint with a correct name using the IPC-7351 >> Naming Convention for Standard SMT Land Patterns. >> >> But I am having some issues, i am using the below document to learn about >> the naming convention: >> https://secure.powercraft.nl/svn/openarm/trunk/working/pcb/documents/footprint-name-spec.pdf >> >> The footprint I want to make is a 54-pin TSOP II (400 mil), see: >> https://secure.powercraft.nl/svn/openarm/trunk/doc/SDRAM/MT48LC16M16A2P-7E/256MSDRAM.pdf >> # page 75, 54-Pin Plastic TSOP >> >> I tried to figure it out but I don't know what the lead span 1(L1) is? >> >> footprint: >> TSSOP-65P-640L1-54N >> 54-pin TSOP II (400 mil) >> TSSOP pin spacing, lead span 1, pin count >> P pin spacing dimension >> L1 lead span 1 dimension >> N pin count count >> >> I also learned to create footprints with the following document: >> https://secure.powercraft.nl/svn/openarm/trunk/working/pcb/documents/land_patterns_20070818.pdf >> I had my ups and downs learning this and had some help trough IRC. >> >> However the creation of a 54-pin TSOP II seems to be able to automate >> using a script. >> >> I looked at the following, but it uses a license I disagree with and I >> can't figure out how it works, I prefer OSI and GPL compatible licenses. >> http://www.luciani.org/geda/pcb/pcb-perl-library.html >> >> Would somebody be able to help me out, what should the name of the >> footprint become and what scripts can I use to make the footprint and how >> can I do this? >> > > I would go for a name like: "TSSOP80P1176X120-54N.fp" as in the IPC > standard IPC-7351 > > 0.80 mm pitch, > 11.76 mm lead span, > X > 1.20 mm height > - 54 leads with Nominal pad conditions (as one of the following: Least, > Nominal, Most). > > Maybe it is a wise thing to avoid "-" characters in footprint file names > or to have a "use-files" line in your gsch2pcb config file and pass a > --skip-m4 flag to disable m4 macro generated footprints to goof up your > pcb stuff. > > Maybe include a vendor and part name too, while footprint artwork > recommendations may vary across vendors and specific parts. > Thanks Bert for the feedback, I am confused, I calculated the pitch on 0.65 mm how did you came to 0.80mm, and could you explain what exactly the lead span is. If I look at page 75 of the datasheet how can I exactly calculate this lead span?
Why did you include the height where did you find this requirement in the IPC-7351 for TSSOP footprints? And why should one avoid the "-" character in footprint names? I see a lot of footprints with this character, would you be willing to discuss the arguments? I call the gsch2pcb with the following arguments: gsch2pcb --use-files --skip-m4 ~/openarm/working/gschem/openarm-sbc.prj --elements-dir ~/openarm/working/pcb/footprints/ I hope that is ok... Sorry for al the questions, I am kind of confused, and searching for answers and help. Best regards, Jelle de Jong _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user