I am trying to route BGA package processors but I've never made before. what is the first step of routing BGA package? first fanout BGA after placement bypass capacitor or placement capacitor after fanout.

Also I've read some user guide and they said that put one 0.1uF cap for every two power balls. is it acceptable?

and you can see my bga fanout, does it look good or I need to improve my fanout.

blue=GND Yellow: Core VDD light blue= I/O VDD

enter image description here

  • \$\begingroup\$ What part is this? How many layers are you working with? Does the manufacturer have an application note for their recommended escape routing? \$\endgroup\$ – duskwuff -inactive- Mar 28 '16 at 20:21
  • \$\begingroup\$ PCB has six layer. \$\endgroup\$ – hardware Mar 29 '16 at 5:32

Given your power and ground balls are concentrated in the center of the device, you should be able to place decoupling capacitors first and route signal escapes second.

One note: it's not a great idea to have multiple balls connected to the same via if you don't absolutely have to. This increases the ground impedance seen by the IC in the BGA package and could cause problems. Where you can, I'd recommend to provide one via per ground ball.

If you search for "BGA escape routing" you can find examples of typical ways to route this, which generally provide a "cross" of wide gaps through the center of the device where decoupling capacitors can be placed.

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  • \$\begingroup\$ Okey I changed my fanout. one power/ground has a via and I put capacitor every Vdd. It will be difficult but ı am gonne figure out. \$\endgroup\$ – hardware Mar 30 '16 at 14:12

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