Added a set of Tcl routines for generating bump bonds for the Micross
post-processing.
diff --git a/sky130/Makefile.in b/sky130/Makefile.in
index e86e1e9..c8fed53 100644
--- a/sky130/Makefile.in
+++ b/sky130/Makefile.in
@@ -328,6 +328,7 @@
rm -f ${MAGIC_STAGING_A}/magicrc
(cd ${MAGICTOP_STAGING_A} ; ln -s ${REV_DIR} current)
cp -rp custom/scripts/seal_ring_generator ${MAGIC_STAGING_A}/.
+ cp -rp custom/scripts/bump_bond_generator ${MAGIC_STAGING_A}/.
cp custom/scripts/generate_fill.py ${MAGIC_STAGING_A}/.
cp custom/scripts/check_density.py ${MAGIC_STAGING_A}/.
${CPP} ${SKY130A_DEFS} magic/${TECH}.tech > ${MAGIC_STAGING_A}/${SKY130A}.tech
diff --git a/sky130/custom/scripts/bump_bond_generator/README b/sky130/custom/scripts/bump_bond_generator/README
new file mode 100644
index 0000000..72a226a
--- /dev/null
+++ b/sky130/custom/scripts/bump_bond_generator/README
@@ -0,0 +1,3 @@
+This set of scripts will generate bump bond layout on the RDL
+layer.
+
diff --git a/sky130/custom/scripts/bump_bond_generator/bump_bond.tcl b/sky130/custom/scripts/bump_bond_generator/bump_bond.tcl
new file mode 100644
index 0000000..7da795a
--- /dev/null
+++ b/sky130/custom/scripts/bump_bond_generator/bump_bond.tcl
@@ -0,0 +1,272 @@
+# SPDX-FileCopyrightText: 2020 Efabless Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
+
+namespace path {::tcl::mathop ::tcl::mathfunc}
+
+#-----------------------------------------------------------------------
+# Routines for generating bump bonds.
+# Use with "micross.tech" technology file.
+#
+# SkyWater top layers:
+# m5 metal5 (thick top metal)
+# glass polyimide (glass) cut
+#
+# Bump bond layers:
+# p1 polyimide via
+# rdl redistribution metal
+# p2 polyimide via2
+# ubm under-bump material
+#
+#-----------------------------------------------------------------------
+
+#-----------------------------------------------------------------------
+# Internal units to microns conversion
+#-----------------------------------------------------------------------
+
+proc magic::i2u {value} {
+ return [expr {((round([magic::cif scale output] * 10000)) / 10000.0) * $value}]
+}
+
+#-----------------------------------------------------------------------
+# Microns to internal units conversion
+#-----------------------------------------------------------------------
+
+proc magic::u2i {value} {
+ return [expr {$value / ((round([magic::cif scale output] * 10000)) / 10000.0)}]
+}
+
+#-----------------------------------------------------------------------
+# make_bump_bond ---
+#-----------------------------------------------------------------------
+# Description:
+# Create geometry for a bump bond in a subcell, centered at the
+# origin. The bump bond itself is a circle (approximated by a
+# 36-sided polygon) of diameter nominally 250um. The RDL layer
+# is 10um larger (rule M4) and the under-bump material layer is
+# 15um smaller (rule U4).
+#
+# Arguments:
+# angle: 0 or 45
+#
+# The angle represents the direction toward which the taper of
+# the RDL layer points. The angle is appended to the subcell
+# name, so the cell is "bump_bond0" or "bump_bond45".
+#
+# The version with suffix "45" has the RDL tapering toward the
+# NE corner when the cell is in its natural orientation. The
+# version suffix "0" has the RDL tapering toward the E side when
+# the cell is in its natural orientation.
+#
+#-----------------------------------------------------------------------
+
+proc make_bump_bond {{orient 0}} {
+ suspendall
+ select top cell
+ set orig_cell [cellname list self]
+
+ load bump_bond${orient} -quiet
+ box values 0 0 0 0
+
+ set rbump 125.0 ;# under-bump material radius, in microns
+ set coords []
+ for {set i 0} {$i < 36} {incr i} {
+ set angle [* $i 10]
+ set arad [/ [* 3.1415926 $angle] 180.0]
+ lappend coords [* $rbump [cos $arad]]um
+ lappend coords [* $rbump [sin $arad]]um
+ }
+ polygon ubm {*}$coords
+
+ set rbump 110.0 ;# polyimide 2 via radius, in microns
+ set coords []
+ for {set i 0} {$i < 36} {incr i} {
+ set angle [* $i 10]
+ set arad [/ [* 3.1415926 $angle] 180.0]
+ lappend coords [* $rbump [cos $arad]]um
+ lappend coords [* $rbump [sin $arad]]um
+ }
+ polygon pi2 {*}$coords
+
+ set rbump 135.0 ;# rdl layer radius, in microns
+ set rdiag [expr {$rbump * sqrt(2.0)}]
+ set coords []
+
+ if {$orient == 45} {
+ for {set i 9} {$i <= 36} {incr i} {
+ set angle [* $i 10]
+ set arad [/ [* 3.1415926 $angle] 180.0]
+ lappend coords [* $rbump [cos $arad]]um
+ lappend coords [* $rbump [sin $arad]]um
+ }
+ lappend coords ${rbump}um
+ lappend coords ${rbump}um
+ } else {
+ for {set i 0} {$i <= 27} {incr i} {
+ set angle [* [+ $i 4.5] 10]
+ set arad [/ [* 3.1415926 $angle] 180.0]
+ lappend coords [* $rbump [cos $arad]]um
+ lappend coords [* $rbump [sin $arad]]um
+ }
+ lappend coords ${rdiag}um
+ lappend coords 0
+ }
+ polygon rdl {*}$coords
+
+ # Make cell bound that encompasses the rdl circle only
+ box grow c ${rbump}um
+ set bounds [box values]
+ property FIXED_BBOX "$bounds"
+
+ load $orig_cell
+ resumeall
+}
+
+#-----------------------------------------------------------------------
+# draw_bump_bond ---
+#-----------------------------------------------------------------------
+# Description:
+# Bump bond is a circle (approximated by a 36-sided polygon) of
+# diameter nominally 250um.
+#
+#
+# Arguments:
+# x y : Coordinates of the bump bond center position, in microns
+# orient : Direction of tapered RDL joining the pad to a route
+# value is in integer degrees, 0 is oriented E (east),
+# and value must be a multiple of 45.
+#-----------------------------------------------------------------------
+
+proc draw_bump_bond {x y {orient 0}} {
+ box size 0 0
+ box position ${x}um ${y}um
+ if {[% $orient 90] != 0} {
+ set bondcell bump_bond45
+ set orient [- $orient 45]
+ } else {
+ set bondcell bump_bond0
+ }
+
+ if {$orient < 0} {
+ set orient [+ 360 $orient]
+ }
+ if {$orient != 0} {
+ set orient [- 360 $orient]
+ }
+ getcell $bondcell $orient child 0 0
+}
+
+#-----------------------------------------------------------------------
+# bevel_corners ---
+#-----------------------------------------------------------------------
+# Description:
+# Bevel the corners of the indicated layer in the current box
+# with the indicated bevel length
+#
+# Arguments:
+# layer : The layer to be cropped
+# length : The length of the bevel (in microns)
+#-----------------------------------------------------------------------
+
+proc bevel_corners {layer length} {
+ suspendall
+ snap internal
+ pushbox
+ set ilength [magic::u2i $length]
+ set side [* $ilength 0.7071]
+ set iside [expr {int($side)}]
+
+ set padbox [box values]
+ set boxwidth [- [lindex $padbox 2] [lindex $padbox 0]]
+ set boxheight [- [lindex $padbox 3] [lindex $padbox 1]]
+
+ set iwidth [- $boxwidth $iside]
+ set iheight [- $boxheight $iside]
+
+ box size $iside $iside
+ spliterase sw $layer
+
+ box move n $iheight
+ spliterase nw $layer
+
+ box move e $iwidth
+ spliterase ne $layer
+
+ box move s $iheight
+ spliterase se $layer
+
+ popbox
+ resumeall
+}
+
+#-----------------------------------------------------------------------
+# draw_pad_bond ---
+#-----------------------------------------------------------------------
+# Description:
+# Draws layers over a wirebond pad to connect to the RDL layer
+#
+# Arguments:
+# x y : Coordinates of the bond pad center position, in microns
+#-----------------------------------------------------------------------
+
+proc draw_pad_bond {x y} {
+ snap internal
+ box values 0 0 0 0
+ box position $x $y
+ box grow c 50um
+
+ # Make sure there is glass underneath. If not, assume the square
+ # center of a 60um x 70um bond pad (60um x 60um).
+ select area glass
+ set stuff [what -list]
+ set layers [lindex $stuff 0]
+ if {$layers == {}} {
+ box position $x $y
+ box size 0 0
+ box grow c 30um
+ } else {
+ set padbox [select bbox]
+ box values {*}$padbox
+ }
+ # Satisfy rule V3: P1 via inside pad cut by 10um
+ box grow c -10um
+ paint pi1
+ bevel_corners pi1 7.5
+
+ # Satisfy rule M3: RDL overlap of P1 >= 10um
+ box grow c 10um
+ paint rdl
+ bevel_corners rdl 10.0
+}
+
+#-----------------------------------------------------------------------
+# draw_pad_route ---
+#-----------------------------------------------------------------------
+# Description:
+# Draws a route on the RDL layer connecting the points given in
+# the coordinate list.
+#
+# Arguments:
+# coords : List of coordinate pairs, in microns
+# width : Route width in microns, default 15
+#-----------------------------------------------------------------------
+
+proc draw_pad_route {coords {width 15.0}} {
+ set icoords []
+ foreach coord $coords {
+ lappend icoords ${coord}um
+ }
+ wire segment rdl ${width}um {*}$icoords
+}
+
diff --git a/sky130/custom/scripts/bump_bond_generator/micross.tech b/sky130/custom/scripts/bump_bond_generator/micross.tech
new file mode 100644
index 0000000..0df9bcc
--- /dev/null
+++ b/sky130/custom/scripts/bump_bond_generator/micross.tech
@@ -0,0 +1,137 @@
+tech
+ 35
+ micross
+end
+
+version
+ version 0.1
+ description "Techfile for Micross bump-bond post-processing for Sky130"
+ requires magic-8.1.111
+end
+
+planes
+ m5
+ rdl
+ ubm
+ glass
+end
+
+types
+ m5 metal5 m5
+ m5 pi1
+ rdl rdl
+ rdl pi2
+ ubm ubm
+ glass glass
+end
+
+contact
+ pi1 metal5 rdl
+ pi2 rdl ubm
+end
+
+styles
+ styletype mos
+ metal5 metal6
+ pi1 metal6 metal7 via6
+ rdl metal7
+ pi2 metal7 metal8 via7
+ ubm metal8
+ glass overglass
+end
+
+compose
+end
+
+connect
+end
+
+cifoutput
+style micross
+ scalefactor 1
+ options calma-permissive-labels
+
+ # NOTE: metal5 and glass are for reference only; they do not get output
+
+ layer PI1 pi1
+ labels pi1
+ calma 5 0
+
+ layer RDL rdl
+ labels rdl
+ calma 10 0
+
+ layer PI2 pi2
+ labels pi2
+ calma 15 0
+
+ layer UBM ubm
+ labels ubm
+ calma 20 0
+
+end
+
+cifinput
+style micross
+ scalefactor 1
+
+ # NOTE: metal5 and glass are for reference; GDS numbers correspond
+ # to SkyWater SKY130
+
+ layer metal5 MET5
+ labels MET5
+
+ layer glass GLASS
+
+ layer pi1 PI1
+ labels PI1
+
+ layer rdl RDL
+ labels RDL
+
+ layer pi2 PI2
+ labels PI2
+
+ layer ubm UBM
+ labels UBM
+
+ calma MET5 72 20
+ calma GLASS 76 20
+ calma PI1 5 0
+ calma RDL 10 0
+ calma PI2 15 0
+ calma UBM 20 0
+
+end
+
+# mzrouter
+# end
+
+drc
+end
+
+extract
+style generic
+ cscale 1
+ lambda 1
+ step 10
+ sidehalo 0
+
+ planeorder m5 0
+ planeorder rdl 1
+ planeorder ubm 2
+ planeorder glass 3
+end
+
+# wiring
+# end
+
+# router
+# end
+
+# plowing
+# end
+
+plot
+ style pnm
+end
