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Tue, 08 Oct 2013 00:21:25 -0700 (PDT) | |
Message-ID: | <5253B271.5020302@gmail.com> |
Date: | Tue, 08 Oct 2013 09:21:21 +0200 |
From: | onetmt <onetmt AT gmail DOT com> |
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To: | geda-user AT delorie DOT com |
Subject: | Re: [geda-user] polygons, arcs and footprints |
References: | <CAM2RGhTKEi4GFb3_sYV8FJRfqr0GTzWfpk28vQ-bDLoQpjvXyQ AT mail DOT gmail DOT com> <524FB65F DOT 9050604 AT gmail DOT com> <CAM2RGhSqy81ZMCjomOkbVCiX9nczAmiVwnhL_DYrBoCYDnqeyw AT mail DOT gmail DOT com> <5253AEAD DOT 6050900 AT gmail DOT com> |
In-Reply-To: | <5253AEAD.6050900@gmail.com> |
Reply-To: | geda-user AT delorie DOT com |
Il 08/10/2013 09:05, onetmt ha scritto: > Il 06/10/2013 03:43, Evan Foss ha scritto: >> The microphone is an ADMP441. They use a ring round the input port to >> seal between the audio input of the microphone and the PCB. > > You cold give this example a try; maybe, you could also refine the > design in order to avoid the sharp edges (I will send you also the basic > trigonometry I used, in case you would). > ...and, sorry: clearance should have been 0.4mm, not 0.4 >> >> On Sat, Oct 5, 2013 at 2:49 AM, onetmt <onetmt AT gmail DOT com> wrote: >>> Il 04/10/2013 23:56, Evan Foss ha scritto: >>>> Hi folks, >>>> >>>> I am trying to make a footprint for an LTC3441. The bottom pad is a >>>> polygon. I know they are not possible in PCB footprints but does >>>> anyone have a good way to emulation one? >>> >>> For other components - for instance the BSC159 mosfet by Infineon - I >>> used several square pads partially overlapped, in order to get the right >>> "polygonal" pad. But in your case, imho, you should use a "normal" >>> footprint and then design the polygons on layer, placing vias also on >>> central powerpad as indicated in datasheet. >>> >>>> >>>> Also I am trying to use a MEMS microphone that uses a ring to seal it >>>> to the PCB. Again I know that does not exist but is there a way around >>>> it? >>> >>> It's difficult to say without knowing the component, but you can obtain >>> a ring - well, a sort of - by using appropriate clearance around an >>> "octagon" pad and placing a rectangle, maybe on a ground layer, around it. >>> >>>> >>>> -Evan >>>> >>> >>> >>> -- >>> Hofstadter's Law: >>> "It always takes longer than you expect, even when you take into account >>> Hofstadter's Law." >> >> >> > > -- Hofstadter's Law: "It always takes longer than you expect, even when you take into account Hofstadter's Law."
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