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bedrock-rnd [bedrock-rnd logo]

bedrock-rnd parametric footprint

Input

  • draw grid in mm
  • draw in "mask and paste"

Result

Footprint attribute:
qfn-ipc(density=B, N=16, BS=3, PP=0.5, PT=0.18~0.30, PC=0.2~0.4, ECPL=1.55~1.8, ECPW=1.55~1.8)

Download footprint file

 

Documentation

qfn-ipc(density=B, N=16, BS=3, PP=0.5, PT=0.18~0.30, PC=0.2~0.4, ECPL=1.55~1.8, ECPW=1.55~1.8)

square flat no-lead (qfn)

Generate a square no-lead flat pack footprint from component drawing using IPC-7351 formulas and tables



qfn-ipc parameters

Ordered list (positions): density,N,NL,NW,BS,BL,BW,PP,PT,PC,PG,PGL,PGW,ECPL,ECPW

name man
dat
ory		description value (bold: default)
density yes board density; C=high density, B=moderate density, A=general (low density)  
N   number of leads in square case  
NL   number of leads on one side along length (vertical) in rectangular case  
NW   number of leads on one side along width (horizontal) in rectangular case  
BS   plastic body size (with tolernace); in case of square body  
BL   plastic body length (vertical; with tolernace); in case of rectangular body  
BW   plastic body width (horizontal; with tolernace); in case of rectangular body  
PP yes nominal pitch (computed assuming no missing leads) Dimension: a number with an optional unit (mm or mil, default is mil)
PT yes pin thickness (with tolernace); really the width of the lead  
PC   pin contact length (with tolernace); specify either this or PGL  
PGL   pin gap (with tolernace) along the length of the body (vertical); specify either this or PC  
PGW   pin gap (with tolernace) along the length of the body (vertical); specify either this or PC  
ECPL yes exposed center pad length (same direction as BL); 0 or empty if no exposed center pad  
ECPW yes exposed center pad width (same direction as BW); 0 or empty if no exposed center pad  
datasheet   url to the datasheet dimensions are coming from  
CPVP yes center pad via grid pitch (distance between vias); 0 or empty for no vias Dimension: a number with an optional unit (mm or mil, default is mil)
CPVHD yes center pad via hole diameter Dimension: a number with an optional unit (mm or mil, default is mil)
CPVCD yes center pad via copper diameter Dimension: a number with an optional unit (mm or mil, default is mil)
CPPAT yes center pad pattern type
none no pattern, round corner rectangle slightly smaller than the pad
chamfer small segments with chamfer corners that avoid vias
nopaste no paste at all
CPPG yes center pad pattern gap; nominal distance between pattern elements Dimension: a number with an optional unit (mm or mil, default is mil)
F yes fab tolerance in +-mm  
P yes part placement tolerance in +-mm  
silk_thickness yes thickness of silk graphic lines; diametr of pin 1 dot is calculated from this too  
mask_offs yes gap between copper pad edge and mask cutout edge  
glue_thick yes default line thickness for glue on adhesive layers; if 0 omit the layer  
glue_dots yes print dots instead of lines for glue when non-zero  
pad_rounding   rectangular pad corner rounding radius (0 for sharp corners) Dimension: a number with an optional unit (mm or mil, default is mil)