FGG676 BGA On 6 Layer PCB with Standard Fabrication Specifications Possible?

[petersanch]

Has any body had success routing a 676 pad 1 mm pitch BGA part using the standard JLCPCB fabrication specifications? This is for a Xilinx FPGA with the FGG676 footprint.
I plan to have one layer for ground, one for power rails, and 4 layers for signals.

[Boscoe]

I’ve never completed this specific case but 1mm pitch is very doable as long as you can fit vias in between the pads. The layer count will only restrict how many pins you can fan out.

[petersanch]

I’ve never completed this specific case but 1mm pitch is very doable as long as you can fit vias in between the pads. The layer count will only restrict how many pins you can fan out.

Thanks. I need to use most of the pins from the FPGA but I wonder if that is too many traces to fan out on 6 layers.

[mon2]

I think you will be facing "via-in-pad" process for your PCB layout. This process is not supported by JLCPCB. Many discounted PCB shops just cannot handle the same. We had to use this in our layout for our ICE40 WLCSP device (16 balls in 1.4*1.4mm) design.

Here is a shop we have used and met in HK numerous times - not JLCPCB pricing but they get the job done for our complex designs at fair prices:

Nicole is a pro in the PCB industry.

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You can also consider ChinaFastPrint but know that after they setup their USA office a few years ago, we could build the bare PCB for a lower cost with North American shops. Since then, we have received contact from former CFP employees in Asia who will broker the job to their plant at "Chinese" prices. CFP has great capability and we have used them for 50++ projects to date but halted the relationship due to the inflated USA branch pricing. From last chats, CFP can support 3mil trace/space and fairly confident they can also handle via-in-pad process.

[filssavi]

The first FPGA I have done a PCB for is a Spartan 7 ftgb196 on a standard 4 layer board, there was absolutely no issues…

You might need more than 6 layers depending on the constrains of your design (how many voltage domains, signal integrity requirements, track width/spacing etc.

But a low cost Chinese manufacturer like JLC or PCBway should be capable of handling it fine