| ID: | 3450 |
| From: | Mychaela Falconia <my...@gmail.com> |
| Date: | Sun, 13 Oct 2019 10:15:56 -0800 |
| Subject: | Re: [pcb-rnd] COT data model (was: non-graphical schematics, layout) |
| in-reply-to: | 3448 from Bob Paddock <bo...@gmail.com> |
| replies: | 3451 from Bob Paddock <bo...@gmail.com> |
Hi Bob, > I hope that is not as literal as it sounds. > > If that means no thermal relief on the GND side then > that can to lead to soldering problems and tombstoning. Openmoko's GTA02 smartphone motherboard really does have all GND- connected SMT component pads directly "drowned" in GND copper pours without any thermal reliefs. They have produced and sold about 15000 units, apparently without any problems in this area, otherwise they would have changed this aspect of their design. My current FCDEV3B (done in Altium, based on a PADS-to-Altium conversion of the modem core from OM GTA02) is exactly the same in this regard, and neither the Altium guy whom I hired to fix the mess the original people left me with nor the assembly shop people have said anything about it. I have produced 36 of these boards so far, and while I am battling yield problems in other areas, there haven't been any issues with pad-to-GND connections. Of course any good PCB layout tool that supports copper pours should have an option controlling what should be done when a component pad of netname X falls inside a copper pour of the same netname X, whether to embed the pad solidly in the pour or to generate thermal reliefs. But it needs to be a configurable option, as different professional PCB designers evidently have different opinions on this issue. M~
Reply subtree:
3450 Re: [pcb-rnd] COT data model (was: non-graphical schematics, layout) from Mychaela Falconia <my...@gmail.com>
3451 Re: [pcb-rnd] COT data model (was: non-graphical schematics, layout) from Bob Paddock <bo...@gmail.com>