This was my first design using a lot of 0201 passives and this was my first use of an LGA. The LGA is a small one. Its a 0.62 mm X 0.62 mm N-Channel Mosfet by On-Semiconductor.
The Mosfet has three pads as you would expect. The drain is a big pad and the gate and source are small pads. Getting the footprint right is always important. It’s even more critical when you have asymmetric pads like this part. The part being so small only adds to it.
The end result of making that big pad too small is that there isn’t enough copper for the solder paste to spread evenly during reflow and most of the Mosfets ended up tilted a bit. Fortunately, the tilt isn’t enough to lift one of the small pads, but it might be when I make the production run of these boards. It’s possible that I might have a little bit more fall out requiring rework.
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