Fanout Spectra or Layout for BGA chip

[hooman]

Fanout Spectra or layout

Hi all,
I have a bga chip on my pcb. Can layout or spectra fanout it organized ( I mean adjustable in degree or in a way)?
Ps: Does anybody has an application note on the subject?

 

[creepy]

Re: Fanout Spectra or layout

Specctra is way better at doing fanout than layout , especially for BGAs. Don't use Layout for that. Just try to understand what all the parameters and options are for, to get the best results. It's all explained in the Specctra help. :wink:

 

[hooman]

Re: Fanout Spectra or layout

Thankx , I now there is no parameter to force the fanout in a degree but by adding some parameters together there is some resolutions.

 

[Johnson]

Re: Fanout Spectra or layout

How to fix the place of via, also how to implement special via alignment pattern?

 

[Uky]

Fanout Spectra or layout

...Just remember to manually fan-out and route your power nets first. The use "Protect all vias/routes" in the DO-file you use when you invoke Specctra.

 

[Johnson]

Re: Fanout Spectra or layout

is there any command to force specctra for making more stubs on big SMD capacitor, I need to add two or three via on this big pads?

 

[Uky]

Fanout Spectra or layout

I would advice against using Specctra for power nets routing. Power nets should be routed manually. The reason for this partially depends upon the license you have. Normally, power planes are not used for routing, and theese are excluded from the number of available layers. If you have a 6layer license, you have 6 routing layers. You may then have any number of plane layers you want. You may thus use a 6 layer licens on a design with 10 layers if 4 of them are power planes.

Furthermore, For the reason of signal integrity, power nets should *never* be routed on ordinary trace layers. Route to a decoupling capacitor manually and then to a via that connects to the plane layer directly.

Always use planes for power nets, and place the vias you think that you need manually.

You can of course use an ordinary routing layer for manually created area fills connected to the power nets you have, but then, a valuable layer will be wasted.

 

[Johnson]

Re: Fanout Spectra or layout

I do not want to route power net, the problem is fanout of big SMD devices. The nubmer of caps is high so doing it manually is not possible or not recommended. There must be a automatic way!!!