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TI DQN import not pretty

Printed From: PCB Libraries Forum
Category: PCB Footprint Expert
Forum Name: Questions & Answers
Forum Description: issues and technical support
URL: https://www.PCBLibraries.com/forum/forum_posts.asp?TID=1299
Printed Date: 07 Nov 2024 at 9:47pm


Topic: TI DQN import not pretty
Posted By: jameshead
Subject: TI DQN import not pretty
Date Posted: 20 Mar 2014 at 4:42am
I don't know immediately if this is something that Pulsonix has failed to convert correctly from the PADS ascii output created via FPX or if the PADS ascii output from FPX is not quite right.

I had a go at creating the TI DQN footprint in the FP Designer.



TI datasheet here: http://www.ti.com/lit/ds/symlink/tlv71330p.pdf

The footprint looked reasonable in FPX


 
The PADS ascii imported to Pulsonix with this result:



I was expecting the drawn copper areas with the small pads for the four corner pads because of the PADS limitations.  I would normaly now create a pad style in Pusonix and make sure it matches up with the drawn corner pads.

The centre pad has been replaced with a square of 0.82 mm side lengths though.  To be honest I was expecting the PADS output to be a drawn copper diamond shape again with the small pad in the centre.  Pulsonix supports a diamond pad shape though so I'd just substitute with this.

I can't check importing the PADS ascii into PADS here though so I'm uploading all the relevant files.

uploads/53/TI_DQN.fpx" rel="nofollow - uploads/53/TI_DQN.fpx

uploads/53/TI_DQN_PADS_ASCII.zip" rel="nofollow - uploads/53/TI_DQN_PADS_ASCII.zip

I'd generally try to use FPX then replace the pads in the imported-to-Pulsonix footprint with defined ones.




Replies:
Posted By: jameshead
Date Posted: 20 Mar 2014 at 5:06am
Just to clarify, the centre pad I would expect on a PADS output to be a small square with a drawn copper polygon for the "diamond" shape pad in the centre.

I pulsonix I would replace this with a pad, pad style being diamond 0.82 mm width, 0.82 mm length.

I was surprised that the PADS asciii had the 0.82mm square pad style. Perhaps there's a rotation in the ascii that Pulsonix has failed to recognise, or is the PADS ascii output not correct?


Posted By: jameshead
Date Posted: 20 Mar 2014 at 7:26am
Here's the footprint done in Pulsonix with Pulsonix's user defined pad styles used.



And a zip file with the Pulsonix format footprint in it.

uploads/53/Texas_Instruments_DQN_in_Pulsonix_format.zip" rel="nofollow - uploads/53/Texas_Instruments_DQN_in_Pulsonix_format.zip



Posted By: chrisa_pcb
Date Posted: 20 Mar 2014 at 4:19pm

The center pin is created as a normal square pad with chamfers. The chamfers happen to be half the corner width. I am able to bring it into PADS without issue(excepting the bug below). Now, if you use a PADS output earlier than 9(which is where built-in chamfering of squares and rectangles was introduced), you should be able to generate it as a pad with associated copper, similar to how a thermal tab with chamfer/rounded corners is produced in all versions.

Keep in mind, there is also a bug where pin 1 is generating a negative pad width. I've fixed this in the code, but to do it manually in the .d set its width and length in the .d to 0.05. Like this:

PAD 0 5 N 0
-2 0.05 RF 0 90 0.05 0
-1 0 R
0 0 R
21 0.05 RF 0 90 0.05 0
23 0.05 RF 0 90 0.05 0



Posted By: chrisa_pcb
Date Posted: 20 Mar 2014 at 5:10pm

I also went ahead and figured out why the pin 1 had the weird blob at the end and fixed it. This is how it now looks in PADS. We'll see about getting you a pre-release with these fixes.



Posted By: jameshead
Date Posted: 21 Mar 2014 at 1:25am
Thanks,
I use the PADS ascii 9.3 format output since this has support for rounded rectangles which Pulsonix also recognises on the import.  I tend to use the .asc output rather than the .d and .p output.


Posted By: AGONZ67
Date Posted: 28 Mar 2014 at 9:41am

I manually created this part a while back and used rectangle as the shape of the pad with equal width and length of 0.5mm. I set the orientation to 45 and it worked perfectly. The shape isn't a square with chamfers it is a square rotated 45 degrees.





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