Use the ATMEL QFN appnote AT88RF1354 to build a more credible footprint

[hw/micropeak] / packages / MO-220.py

diff --git a/packages/MO-220.py b/packages/MO-220.py
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+#!/usr/bin/python
+# Copyright 2011 by Bdale Garbee <bdale@gag.com>.  GPLv2
+#
+# Program to emit PCB footprint for MO-220 package used by the ATTiny85
+#
+
+# dimensions in mm from the ATTiny datasheed
+
+PinWidth = 0.23          # b   
+PinHeight = 0.55  # L
+PinSpacing = 0.50 # e
+Overall = 4.25    # E
+GndSquare = 2.60  # D2 & E2
+CoreSquare = 2.60
+
+# ATMEL specifies 120-150 microns between pad and solder mask
+# AT88RF1354 Appplication note
+#
+PinResist = PinWidth + (2 * 0.07)
+
+import sys
+
+# we're going to use the 1/100 of a mil fundamental unit form
+
+def mm2mils100( mm ):
+       return int( mm / 25.4 * 1000.0 * 100.0 + 0.5 )
+
+print '# author: Keith Packard'
+print '# email: keithp@keithp.com'
+print '# dist-license: GPL 2'
+print '# use-license: unlimited'
+
+print 'Element[0x0 "MO-220" "" "" 0 0 0 0 0 100 0x0]'
+print "("
+
+# pad under the chip, must be grounded
+print '   Pad[',\
+       mm2mils100(0), \
+       mm2mils100(0), \
+       mm2mils100(0), \
+       mm2mils100(0), \
+       mm2mils100(GndSquare), \
+       0, \
+       0, \
+       '"pin21" "21" "square,nopaste"]'
+
+# vias in the ground pad under the chip
+#for viarow in range (-1,2):
+#  for viacol in range (-1,2):
+#    print '   Pin[',\
+#      mm2mils100(2 * viacol * CoreSquare / 5), \
+#      mm2mils100(2 * viarow * CoreSquare / 5), \
+#      2900, \
+#      2500, \
+#      0, \
+#      1500, \
+#      '"pin21" "21" 0x0002]'
+
+# break pad under chip into a grid to control the resist and paste masks
+
+blocks=3
+
+for viarow in range (-1, 2):
+  for viacol in range (-1, 2):
+    if (viarow in (-1, 1)) and (viacol in (-1, 1)):
+      # copper sub-square with resist over vias
+      print '   Pad[',\
+       mm2mils100(viacol * CoreSquare / blocks), \
+       mm2mils100(viarow * CoreSquare / blocks), \
+       mm2mils100(viacol * CoreSquare / blocks), \
+       mm2mils100(viarow * CoreSquare / blocks), \
+       mm2mils100((CoreSquare)/blocks), \
+       0, \
+       0, \
+       '"pin21" "21" "square,nopaste"]'
+    else:
+      # copper sub-square without resist
+      print '   Pad[',\
+       mm2mils100(viacol * CoreSquare / blocks), \
+       mm2mils100(viarow * CoreSquare / blocks), \
+       mm2mils100(viacol * CoreSquare / blocks), \
+       mm2mils100(viarow * CoreSquare / blocks), \
+       mm2mils100((CoreSquare)/blocks), \
+       0, \
+       mm2mils100((CoreSquare)/blocks), \
+       '"pin21" "21" "square,nopaste"]'
+      # copper spot to control paste mask generation
+      print '   Pad[',\
+       mm2mils100(viacol * CoreSquare / blocks), \
+       mm2mils100(viarow * CoreSquare / blocks), \
+       mm2mils100(viacol * CoreSquare / blocks), \
+       mm2mils100(viarow * CoreSquare / blocks), \
+       1500, \
+       0, \
+       mm2mils100((CoreSquare)/blocks), \
+       '"pin21" "21" "square"]'
+
+# pins
+for pin in range (1,6):
+    print '   Pad[',\
+       mm2mils100((-3 + pin) * PinSpacing), \
+       mm2mils100(-Overall/2 + PinWidth/2), \
+       mm2mils100((-3 + pin) * PinSpacing), \
+       mm2mils100(-Overall/2 + PinHeight - PinWidth/2), \
+       mm2mils100(PinWidth), \
+       mm2mils100(PinSpacing - PinWidth), \
+       mm2mils100(PinResist), \
+       '"pin%i"' % (16-pin), '"%i"' % (16-pin), '0x0000]'
+
+    print '   Pad[',\
+       mm2mils100((-3 + pin) * PinSpacing), \
+       mm2mils100(+Overall/2 - PinHeight + PinWidth/2), \
+       mm2mils100((-3 + pin) * PinSpacing), \
+       mm2mils100(+Overall/2 - PinWidth/2), \
+       mm2mils100(PinWidth), \
+       mm2mils100(PinSpacing - PinWidth), \
+       mm2mils100(PinResist), \
+       '"pin%i"' % pin, '"%i"' % pin, '0x0000]'
+      
+    print '   Pad[',\
+       mm2mils100(Overall/2 - PinHeight + PinWidth/2), \
+       mm2mils100((-3 + pin) * PinSpacing), \
+       mm2mils100(Overall/2 - PinWidth/2), \
+       mm2mils100((-3 + pin) * PinSpacing), \
+       mm2mils100(PinWidth), \
+       mm2mils100(PinSpacing - PinWidth), \
+       mm2mils100(PinResist), \
+       '"pin%i"' % (11-pin), '"%i"' % (11-pin), '0x0000]'
+
+    print '   Pad[',\
+       mm2mils100(-Overall/2 + PinWidth/2), \
+       mm2mils100((-3 + pin) * PinSpacing), \
+       mm2mils100(-Overall/2 + PinHeight - PinWidth/2), \
+       mm2mils100((-3 + pin) * PinSpacing), \
+       mm2mils100(PinWidth), \
+       mm2mils100(PinSpacing - PinWidth), \
+       mm2mils100(PinResist), \
+       '"pin%i"' % (15+pin), '"%i"' % (15+pin), '0x0000]'
+
+print '   ElementArc[',\
+       mm2mils100(-2.0), \
+       mm2mils100(2.0), \
+       '500 500 0 360 1000 ]'
+print ")"