| T O P I C R E V I E W |
| rbuck |
Posted - 03 Jul 2009 : 01:54:39
Does anyone have a suggestion on how to lay out the pads for this part?:
http://www.coilcraft.com/pdfs/lpd4012.pdf
The only way I can see to do it is to layout .031 square pads at each corner of each pad and then create a copper pour area between the pads. The problem with this is I end up with 8 pads instead of 4 pads. The schematic part will only have 4 pads so there would be some issues when performing the integrity check.
Ray |
| 5 L A T E S T R E P L I E S (Newest First) |
| Peter Johnson |
Posted - 06 Jul 2009 : 12:14:00
I think the best option is the rectangular pad shape rotated through 45 degrees, as there are no issues with creating mask or silk plots. If you want to go the custom pad route, there's an FAQ for it:
http://numberone.com/faq.asp?S=article&N=FAQ/Easy-PC/Libraries and Library Items/Creating custom pad shapes.htm&T=Easy-PC : Libraries and Library Items : Creating custom pad shapes
The biggest issue with merging pads is that generating Gerber files needs careful management, but I'll pass that suggestion on to the programming team. |
| rbuck |
Posted - 03 Jul 2009 : 21:04:42
olga,
Peter's suggestion worked. It took a little time but the results were good. I could not get the filled shape 100% aligned with the pads but it is 99.999% accurate. I had to create 8 pads to start with and get them on the correct X-Y co-ordinates. Then I used one pad at each corner as the starting point and made the filled shape match the corner of the related pad. When the filled shape was finished, I deleted the extra pad and associated the filled shape with the remaining pad.
I like pedro's suggestion. It would have been easier to make the part if I could have placed 4 pads at each corner and then merged the pads. And it would have been 100% accurate because I could have controlled the size of each of the pads.
Peter, pedro's suggestion of being able to merge multiple pads into one pad is a very good idea if it could be accomplished.
Ray |
| olga |
Posted - 03 Jul 2009 : 15:30:13
Hi,
Something I've been told (thanks Peter!) & wrote down in my 'notes of cute things to make EPC easier to use' but haven't had cause to try yet is the following:
"To create custom pad, use a normal pad as a basis, then add a filled shape to make it the outline you want. Link the shape to the pad, by going to the properties of the shape and associating it with the appropriate pad."
As I say, I haven't tried it for myself yet, but I think it will work, however, YMMV!
Best wishes,
Olga. |
| pedro444 |
Posted - 03 Jul 2009 : 15:23:52
Hello everybody,
The chamfered rectangle looks like exactly what you need for the coilcraft part. Make one to the right shape then duplicate, place & rotate to suit.
The problem I come across is when I need a pad that is an irregular shape, then there is no option but to have additional pads laying side by side and ignore the drc bleats.
What I would like to see is an option to merge multiple pads into a single pad, a bit like merge shapes. That way I can make a pad of any shape from the primitives we already have.
Of course the other way is to have a proper pad editor then you could have any copper shape and maybe any number of holes. I suspect that would have to be considered for another version
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| olga |
Posted - 03 Jul 2009 : 11:47:56
Hi Ray,
Could you maybe do something with the chamfered rectangle pad style? Get one pad the shape & size you want it to be, then rotate it through 45 degrees to get it on the angle.
Alternatively, you could lay the two pads at the corners & place another rectangular pad at an angle to make the rest of the shape.
When I've had a part with more pads than the schematic has pins, I think I've defined the schematic part to have the right number of pins & just joined them on the schematic. It was actually a very similar part I had to do that with!
I think that other people have also mentioned the problem with this. It is rather annoying, I agree. Peter... any chance of getting a fix for this onto the 'wish-list'? 
Best wishes,
Olga. |
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