Creating Web/Thermal shape for paste mask

You could create four static shapes on the package geometry / paste top layer in the footprint.

You could also create a shape symbol and add it to the pad stack.

That is the way I have been approaching it, but was looking to see if Cadence had a skill file that would take od, id, w and angle and create one. I could not find anything and so I created a python script that does the math and generates a pcb script that can be replayed in allegro. Works great, I provide the four parameters, run it, and it generates the script that I replay and create the shape as seen below.

Hi JS,

Nice work !. Might I ask did you come up with a method to fill the shapes and what was the key method needed to create the shape geometry within the PCB Editor so as to get your wagon wheel type shape.

Best Regards

Hi JS202408156358!

You can refer this code.

;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
axlCmdRegister("create_thermal_shape" 'create_thermal_shape)
(defun create_thermal_shape ()
let((angle layer in_put)
layer = "BOARD GEOMETRY/ASSEMBLY_NOTES"
axlVisibleLayer(layer t)
in_put = axlEnterString(?prompts list("Please enter 3 params:\n Ex: 4,100,25"))
if(in_put != nil && length(parseString(in_put ",")) == 3 then
point = axlEnterPoint(?prompts "" ?points nil ?gridSnap t)
if(point != nil then
p_in_put = parseString(in_put ",")
id = atoi(car(p_in_put))
ra = atof(cadr(p_in_put))
w = atof(caddr(p_in_put))
printf(" id: %d\n ra: %.2f\n w: %.2f\n" id, ra, w)
d = axlMXYAdd( 0:ra point)
r_path = axlMakeDynamicsPath(list(list(d d 0.0 point ra t) list(d d) ) )
poly1 = car(axlPolyFromDB(r_path ?layer layer ?endCapType 'ROUND))
poly_expand = car(axlPolyExpand(poly1 -w 'NONE))
poly2 = car(axlPolyOperation(poly1 poly_expand 'ANDNOT))
wheel = 360.0 / id
angle = 0.0
poly_list = nil
tmp_point = axlMXYAdd( 0 : (ra + w) point)
while(angle <= 360.0
point_rotate = axlGeoRotatePt(angle tmp_point point)
r_path2 = axlMakeDynamicsPath(list(list(point point_rotate w) ) )
poly3 = car(axlPolyFromDB(r_path2 ?layer layer ?endCapType 'NONE ?line2poly t))
poly_list = cons(poly3 poly_list)
angle = angle + wheel
)
poly_or = car(axlPolyOperation(car(poly_list) cdr(poly_list) 'OR))
poly_or2 = axlPolyOperation( poly2 poly_or 'ANDNOT)
foreach(poly poly_or2
axlDBCreateShape(poly t layer nil)
)

)
)
)
)
;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Regards.

HoangKhoi.

Hi HoangKhoi,

Thanks for sharing your skill routine. It works very well. I'm sure many will find it useful.

Best Regards.