Fanout SMD

[hgregg]

I'm running version 9.1.221 of Ultiboard Power Pro and am having troubles with the Fanout SMD command. I am trying to fanout a single component but never get good results. I end up with about half the pins fanned and lots of DRC errors. No matter what I put for the Via Spacing Factor, the vias come out in the same places everytime. I also have many pins on the component that are not in a net, but the Fanout command only tries to do the ones with nets. I wish there was an option to tell it to do all pins regardless of net assignment or lack thereof. 

I have two questions from this:

1) Is there a way to make this work better in the version I have (got any tips or tricks?)?

2) Does this work any better in the newest version of Ultiboard?

 Thanks,

Hg

[_user32]

hgregg ,

I am not sure if there is improvement in v10.1.  However, to alleviate one of your issues, I use a custom No Connect "NC" symbol to connect to any unused pin on an SMD (which will resolve the issue that you had below).  You can then connect it later if you need to utilize the pin and the fanout within the PCB will still be preserved.  Using a specified NC will cause an artificial net to be created and the fanout will work correctly.  There are also some other suggestions for you to try listed here...

1. Use a NC for unused pins before fanout

2. Before routing or ground plane placement, fanout the SMD first in an open area away from other components.  You can then select entire SMD + fanouts and move them into a desired position.

3. If possible use the smallest via size as allowed by the PCB manufacturer (the default VIA used in Ultiboard is rather large for smaller SMD work)

4. Make sure you decrease the VIA grid (default is 20mil - I generally set it to 1 mil).   This will make the VIA placement a little easier.

5. Reduce the default net clearance as small as possible (as allowed by PCB manufacturer) as this will allow for tightest placement.

Here are some screenshots showing the technique for 68 pin PLCC.   I also included the part file (.prz) for the useful custom NC symbol used in this example.

Regards,

Patrick Noonan
Business Development Manager
National Instruments - Electronics Workbench Group
50 Market St. 1-A
S. Portland, ME 04106
Email: patrick.noonan@ni.com
Tel. (207) 892-9130
Fax. (207) 892-9508 

[hgregg]

Thank you for the tips and custom NC idea. I'm still wondering about that Via Spacing Factor though because it seems to do nothing. Have you tried it?

Perhaps another reader will chime in here about using Fanout in V10.1

Hg

[_user32]

 hgregg ,

According to the help, the Via Spacing Factor is for BGA parts only, so it would have not impact on anything similar to LCC parts.

Regards,

Patrick Noonan
Business Development Manager
National Instruments - Electronics Workbench Group
50 Market St. 1-A
S. Portland, ME 04106
Email: patrick.noonan@ni.com
Tel. (207) 892-9130
Fax. (207) 892-9508 

[hgregg]

LOL

I find the "help" so unhelpful that I never thought to look there. Thanks Patrick!