Hello, For several home projects a try to create a "controller card" with STM32MP151DAC1 with package TFBGA361 to use a lot of input/output. I already have the most important chips in stock. (SOC, RAM, Flash, Ethernet, PMIC and hub USB) Now, I try to test routing between RAM and SOC to determine the routing constraints and see how to place components. Now the issue : TFBGA361's pad (outside) : diameter 0,3mm 1 Center pad to center pad 0,5mm. There is 0.2mm of space left. I try to use 4 layers. Footprint:  Now, look at left pads. Outside I can pull out wire directly or use via. But inside (pad in red zone), I can't pull out wire directly.  JLCPCD capabilities to BGA:  capabilities with via is 0,2mm to hole and 0,4mm to diameter. capabilities with trace 0.09mm capabilities with spacing  0.09mm There should be 0,27mm spacing to use trace.  Via in center don't work.  I deduce that routing is possible but how? If pad are via, it's work. Is this going to cause soldering problems with reflow? I have to put a via on each pad to have the same height for each pad? In this case, it doesn't work because I couldn't get the wires out. Are the vias filled with resin to prevent sagging or rising air?  Do you know how can I route it? Thanks in advance.