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Chip Component Land Pattern

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bakhmat View Drop Down
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    Posted: 13 Sep 2012 at 7:38am
Hi all,
 
How can I calculate Gmin for chip component (IPC-7351B)? 
I can't get the PCB Footprint Expert result.  Confused

Gmin=Smax-2*JH-SQRT(Cs^2+P^2+F^2), where 
Smax=Smin+Stol(RMS);
Smin=Lmin-2*Tmax;
Cs=Stol(RMS);
Stol(RMS)=SQRT[(Lmax-Lmin)^2+(Tmax-Tmin)^2]
JH=0 (Nominal Density for 0603 chip component)
P - placement tol.; F - fabrication tol.

Is that right?

Thanks in advance
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Nick B View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Nick B Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 2012 at 2:31am

For those who want to customize library rules to meet manufacturer’s requirements and want to see how it works to create customized Footprint Expert DAT files (personal rules).

 
IPC-7351C Reference Calculator  (forum login is required to download)
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