Footprint with vias in allegro

[jayasree jayaraj]

Hi,
I am trying to create a footprint for LAN8742A-CZ-TR. I want to add vias in pads of footprint.I don't know how to create footprint with vias in allegro. Please tell how to create footprints with via using cadence allegro. i have attached datasheet of this component.

 

[BigBoss]

Register yourself www.ultralibrarian.com then download the footprint then add your vias as you wish..

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app.ultralibrarian.com

 

[jayasree jayaraj]

Hi,
My doubt is how to add vias in footprint.I mean in .dra file how can we add vias?

 

[jayasree jayaraj]

Hi,
How to add thermal vias in thermal pad of footprints in allegro? Can you please suggest any videos or steps of adding thermal vias in footprints

 

[HasHx]

Hello,

I have had the same issue before and I worked it out in a weird way but it was the only way that enabled me to do so.

First go to your schematic symbol and add pins with the same number of vias needed (you can make these pins invisible to avoid confusion).

Then go to your footprint and chose those pins as a via pad and place them where needed.

I have attached an example footprint, hope you find it useful.

If you do otherwise you will always get DRCs and bad connections, Good luck.

 

[jayasree jayaraj]

Hi,
I did as per your suggestion.but as my thermal pad is smd and via is throughole i am getting drc error of thru pin to smd pin spacing.In my constraint manager i had set spacing of 0.127mm. I have attached my footprint below.

 

[lhademmor]

One way to do this is to create a smd pad of size 0.25*0.25 mm and place it in the middle of the pad, now create a shape that covers the heat pad, and place Via's in the shape. Remember large heat pads should not have 100% paste mask but rather a bunch of small areas summing up to 50-60%.
Another way to do it is to do a through hole pin, where bottom and inner layers are set to zero and instead of one hole do multiple in a pattern.

 

[BigBoss]

VIAs are not necessary while creating a footprint. Place a single/multiple Die-pad as you wish then place the VIAs while routing your PCB. Otherwise Netlist errors or Space Constraint errors occur

 

[FvM]

Adding vias in PCB design is an option, but Altium supports vias in footprint.