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How to add solder mask to teardrops ?

Hey guys , when i was making a keyboard pcb , i found this images.

this is a pcb of keyboard too . what interested me is that all of it's clines , thr-pins , vias and teardrops are added solder masks , and shows out an open-windowed , blackgold effect , and i think i want this visual effects too .

then i tried it in allegro . first i export a sub_drawing file out of the pcb , selecting the clines and vias before picking the origin spot , and a .clp file is there in the folder where the pcb .brd file is . Then i open the clp file with the vscode , and replaced all of the "etch/top" and "etch/bottom" with ''Board_geometry/soldermask_top'' and ''Board_geometry/soldermask_bottom '' . then , i import the modified clp file into the pcb , and this help to add a mask layer to the clines and vias . in the 3d viewer it is like this

it shows the same effect in the first image i posed , the clines , vias are added soldermask .

but i can not achieved the effect in the second image , cause i don't know how to add soldermask to the teardrops . when i exported the subdrawing file , i can only select the clines vias pins but not the teardrop .

Anybody knows know to add soldermask to the teardrops can give me some ideas ?

xiaoquana over 5 years ago

Anybody knows how to add soldermask to the teardrops can give me some ideas ?
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RFinley over 5 years ago in reply to xiaoquana

The IPC association recommends adding teardrops to pads with drills to minimize bare board quality failures if the actual drill hole ends up being too close to the edge of the pad (breakout.) Teardrops in copper are also needed to add flex circuit reliability.

If there isn't a drill hole to accommodate, except for RF connection tapers, I don't know of a universal benefit for teardrops on SMD pads.

Soldermask does several things. One is keep solder from escaping or flowing away from the connection. Molten solder gets drawn into holes via capillary action or it spreads as far as it can because of gravity, risk of a dry solder joint.

vias adjacent to SMD pads need to be covered by mask.
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excellon1 over 5 years ago

Hi,

Generate your gerber data for the layer you need First. Then import it back in and place it on the Board Geometry layer. See if that works, thinking it should. (Click Load File) to position the artwork over your board outline so you get a 1:1 match.

All the best.
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xiaoquana over 5 years ago in reply to excellon1

thanks， it maybe a possiable way , i will hvae a try.
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