Actions
Forum Thread Details
  • State Not Answered
  • Replies 2 replies
  • Subscribers 177 subscribers
  • Views 722 views
  • Users 0 members are here
Related

0.65mm bga routing

Former Member

Hi all. I am working on a project involving a 0.65mm pitch BGA chip. I am having trouble getting the vias under the BGA to a proper size, using the Sunstone PCB design rules. I see restring settings, I temporarily changed those to say drill diameter is 50% of outer layer diameter, I saw no change. I am (for now) using the free version of eagle cad. I found a document explaining proper routing under the BGA, basically putting vias in every other block of four pads.

 

Also, I am using about 50 of the 121 pads, is it possible to do everything on a two layer board?

 

Thank you.

  • 0

    On 17.07.2015 18:21, Scott Carlson wrote:

    Hi all. I am working on a project involving a 0.65mm pitch BGA chip. I

    am having trouble getting the vias under the BGA to a proper size, using

    the Sunstone PCB design rules. I see restring settings, I temporarily

    changed those to say drill diameter is 50% of outer layer diameter, I

    saw no change. I am (for now) using the free version of eagle cad. I

    found a document explaining proper routing under the BGA, basically

    putting vias in every other block of four pads.

     

    Also, I am using about 50 of the 121 pads, is it possible to do

    everything on a two layer board?

     

    First, you can lock pad diameters within the device editor. I bet they

    are now set to "auto" and changes with restring settings.

     

    Second, you last question suggests makes me wonder what kind of BGA

    device you are working with. None of the ones I ever seen can only use

    50 of 121 pads, and even considering two layer boards make me think you

    are not serious. But let me know what device you are considering; You

    may surprise me.

     

     

  • 0

     

    Am 17.07.2015 um 18:21 schrieb Scott Carlson:

    Hi all. I am working on a project involving a 0.65mm pitch BGA chip. I

    am having trouble getting the vias under the BGA to a proper size, using

    the Sunstone PCB design rules. I see restring settings, I temporarily

    changed those to say drill diameter is 50% of outer layer diameter, I

    saw no change. I am (for now) using the free version of eagle cad. I

    found a document explaining proper routing under the BGA, basically

    putting vias in every other block of four pads.

     

     

    For the vias, please check the settings in the Design Rules' Restring

    tab. There are settings that decide about via diameters. Please check

    the minimum value. If you are not sure, pleae contact your board

    manufacturer and ask what is the best combination of drill size and

    via diameter....

     

     

    --

    Mit freundlichen Gruessen / Best regards

    Richard Hammerl

      CadSoft Support -- hotline@cadsoft.de

      FAQ: http://www.cadsoft.de/training/faq/