FB236 PCB Routing
Posted: Thu Jul 08, 2021 2:18 pm
Hello,
I'm looking at the best way of routing out the connections from an FB236 package which according to IPC specifies a nominal 0.25 mm diameter pad for the 0.3 mm diameter solder ball. The minimum advised track width and clearance I'm seeing advised by PCB manufacturers is 0.1 mm, which means it's not possible to route tracks between pads given the 0.5 mm pitch as I would need a minimum distance between the pads of 0.3 mm. In theory, I could reduce the pad diameter to 0.2 mm to create this desired 0.3mm gap and stay within IPC guidelines, but this doesn't necessarily feel like the right way to go.
So I'm looking at options for via-in-pad and micro-vias and am looking for recommendations please. I think that the 0.25 mm pad size is likely too small for via-in-pad, even to only go down to the next layer, but would welcome any guidance and experience.
For example, would it be ok to increase the pad diameter to allow via-in-pad, and if so by how much?
Thanks!
Al
I'm looking at the best way of routing out the connections from an FB236 package which according to IPC specifies a nominal 0.25 mm diameter pad for the 0.3 mm diameter solder ball. The minimum advised track width and clearance I'm seeing advised by PCB manufacturers is 0.1 mm, which means it's not possible to route tracks between pads given the 0.5 mm pitch as I would need a minimum distance between the pads of 0.3 mm. In theory, I could reduce the pad diameter to 0.2 mm to create this desired 0.3mm gap and stay within IPC guidelines, but this doesn't necessarily feel like the right way to go.
So I'm looking at options for via-in-pad and micro-vias and am looking for recommendations please. I think that the 0.25 mm pad size is likely too small for via-in-pad, even to only go down to the next layer, but would welcome any guidance and experience.
For example, would it be ok to increase the pad diameter to allow via-in-pad, and if so by how much?
Thanks!
Al