Updated clear area density limits based on input from SkyWater.

sky130/custom/scripts/check_density.py

diff --git a/sky130/custom/scripts/check_density.py b/sky130/custom/scripts/check_density.py
index f2e529c..34b2a76 100755
--- a/sky130/custom/scripts/check_density.py
+++ b/sky130/custom/scripts/check_density.py
@@ -544,50 +544,50 @@
     liaccum = sum(lifill) / atotal
     print('')
     print('LI Density: ' + str(liaccum))
-    if liaccum < 0.35:
+    if liaccum < 0.50:
         print('***Error:  LI Density < 35%')
-    elif liaccum > 0.70:
-        print('***Error:  LI Density > 70%')
+    elif liaccum > 0.60:
+        print('***Error:  LI Density > 60%')
 
     met1accum = sum(met1fill) / atotal
     print('')
     print('MET1 Density: ' + str(met1accum))
     if met1accum < 0.35:
         print('***Error:  MET1 Density < 35%')
-    elif met1accum > 0.70:
-        print('***Error:  MET1 Density > 70%')
+    elif met1accum > 0.60:
+        print('***Error:  MET1 Density > 60%')
 
     met2accum = sum(met2fill) / atotal
     print('')
     print('MET2 Density: ' + str(met2accum))
     if met2accum < 0.35:
         print('***Error:  MET2 Density < 35%')
-    elif met2accum > 0.70:
-        print('***Error:  MET2 Density > 70%')
+    elif met2accum > 0.60:
+        print('***Error:  MET2 Density > 60%')
 
     met3accum = sum(met3fill) / atotal
     print('')
     print('MET3 Density: ' + str(met3accum))
     if met3accum < 0.35:
         print('***Error:  MET3 Density < 35%')
-    elif met3accum > 0.70:
-        print('***Error:  MET3 Density > 70%')
+    elif met3accum > 0.60:
+        print('***Error:  MET3 Density > 60%')
 
     met4accum = sum(met4fill) / atotal
     print('')
     print('MET4 Density: ' + str(met4accum))
     if met4accum < 0.35:
         print('***Error:  MET4 Density < 35%')
-    elif met4accum > 0.70:
-        print('***Error:  MET4 Density > 70%')
+    elif met4accum > 0.60:
+        print('***Error:  MET4 Density > 60%')
 
     met5accum = sum(met5fill) / atotal
     print('')
     print('MET5 Density: ' + str(met5accum))
     if met5accum < 0.45:
         print('***Error:  MET5 Density < 45%')
-    elif met5accum > 0.86:
-        print('***Error:  MET5 Density > 86%')
+    elif met5accum > 0.76:
+        print('***Error:  MET5 Density > 76%')
 
     if not keepmode:
         os.remove(magpath + '/check_density.tcl')