Strange footprint design - Page 1
Forum section: electronics / general

author: maurosmartins
author_rank: Regular Contributor
timestamp: May 20, 2013, 10:34:01 pm
content: Hello all,I've recently started to use Altium Designer and I've encountered several difficulties designing some footprints.The first is for an inductor, the datasheet shows the recommended footprint configuration as follows:Reading the following tutorialhttp://wiki.altium.com/display/ADOH/Creating+a+Custom+Pad+ShapeI desgined this:Unfortunately I think this is not entirely correct because on the layout I get errors:I have another doubts but I'll place them one at a timeThanks in advanced,Best regards, Mauro.

author: free_electron
author_rank: Super Contributor
timestamp: May 20, 2013, 11:09:01 pm
content: dnu design - netlist - update free primitives from component padsthat will fix that problem

author: maurosmartins
author_rank: Regular Contributor
timestamp: May 20, 2013, 11:51:51 pm
content: Hello all,@free_electron, thank you very very much, that did the trickI'll post my following question. I need to use a current sensor and decided to use a ACS755xCB-050 from Allegro MicroSystems, the recommend footprint is as follows:How should I design this footprint?Best regards, Mauro.

author: Randall W. Lott
author_rank: Regular Contributor
timestamp: May 21, 2013, 12:58:56 am
content: Make sure to make an opening in the soldermask, or you won't be soldering that part very well!

author: free_electron
author_rank: Super Contributor
timestamp: May 21, 2013, 02:45:14 am
content: Place center oblong pad that is about 20 mils wider and longer than the hole you need.In pad properties select that this is a slot. Give it the center offset and length.Then populate loose round pads adound it. Finish off woth a polygon. I. The i spector tick the checkbox that says you want soldermask opening above the polygon.

author: maurosmartins
author_rank: Regular Contributor
timestamp: May 22, 2013, 09:07:59 pm
content: Hello all,@Randall W. Lott and free_electron, thank you for your replies, I haven't got the chance to try it, I'll give feedback as soon as I do.In the meanwhile I discovered something related to the previous post that might also be related to your answers.Using altium 3D mode I can see that on the inductor pads it didn't created the opening to be soldered as can be seen in the following image:I should have the entire custom pad be I only have the pads the provide the designator.Any thoughts on this matter?Best regards, Mauro.

author: free_electron
author_rank: Super Contributor
timestamp: May 22, 2013, 10:16:10 pm
content: you need to setup the opeing in the pcb inspector for your custom shape to open the soldermaskmake sure the PCB inspector is open ( bottom right corner of main window : click PCB select PCB inspector )click on the polygon you have drawn.look at the inspector windowit will show layer, net, keepout ... etc.look where it says "solder mask expansion mode". set that to manual ( or to from rule of you use it rule driven from the pcb )if you set it to manual now you can change the "solder mask expansion value" to whatever value for the opening you want. not that this is the opening around the polygon. if your polygon is 20x20 mils and you type in 4 the opening will be 28 by 28 centered on the polygone so you get a 4 mil wide oversize.if you set it ot 'from rule' the tools will automatically fill in 4 mils as that is the default rule for soldermask. you can override that from the design rules later

author: maurosmartins
author_rank: Regular Contributor
timestamp: May 22, 2013, 11:26:10 pm
content: free_electron, again, thank you for the quick reply.Probably I'm not in the same menu as you are saying because I cannot find the following option:Quote from: free_electron on May 22, 2013, 10:16:10 pmBest regards, Mauro.

author: Niklas
author_rank: Frequent Contributor
timestamp: May 28, 2013, 05:18:51 pm
content: Mauro, which version of Altium are you using? The PCB Inspector window in the most current version has 4 more lines in the dialog window compared to the screenshot you uploaded: Solder Mask Expansion, Solder Mask Expansion Mode, Paste Mask Expansion and Paste Mask Expansion Mode.A quick and dirty workaround could be to manually place polygons with solder mask and paste mask on top of the copper polygon in the PCBLib editor.

author: maurosmartins
author_rank: Regular Contributor
timestamp: June 08, 2013, 02:53:38 pm
content: Hello all,@Niklas, thank you for the reply and sorry for the delay, I thought no one had answered me.Quote from: Niklas on May 28, 2013, 05:18:51 pmNiklas, my Altium version is 10.391.22Best regards, Mauro.