Tool/software:
Hello. We have an application that requires an AM263 to be mounted on a power electronics board with thick copper layers, with all layers having 2oz copper minimum although 4oz is desirable. There are minimum trace/space requirements for such boards. Our manufacturer tells us they can do no less than 4.5mils with a 2oz board.
The AM263 BGA ZCZ requires very small traces and clearances for proper fanout, as well as filling copper pours for thermal management. One example is shown below, which is an image of fanout on Layer 3 for the TI Control Card. Here, there are 4mil traces, 4.5mil spacing between trace and nearest via, with vias having 8mil drills and 18mil diameters.
To achieve 4.5mil trace/space, it seems that the only solutions are the following:
* Expand the PCB to many more layers, with 1oz layers reserved for the BGA and >2oz layers reserved for power. This is obviously very costly.
* Reduce the BGA via drill size from 8mil down to perhaps 6 mil (0.15mm).
Reducing the drill size might affect thermal performance and TI recommends maximizing this where possible, according to the hardware design guide.
Note: our PCB is 2mm thick.
My questions are:
Is TI familiar with designs placing this BGA on such boards? Does TI recommend a different solution from those posed above?
If we do reduce drills to 6mil, is there a reason to believe the package cannot be adequately cooled? Note that we will not be running this device at its maximum processing power level.
