Hi,
I am trying to design a PCB for a BME680 sensor.
That is a LGA 3x3mm package with a metal top.
The 8 pads on the package are 0.4x0.4mm.
My problem is, i do not get proper solder contacts on all pads.
My process uses a PCB from one of the chinese PCB services, stainless steel stencil for solder paste, hand placement, reflow oven.
This works fine for similar sized packages, eg. 3x3 WDFN.
However WDFN have their pads on the edge, LGA somewhere in the middle.
My question is, are there any tips/optimizations i can do to improve results:
- make pads on PCB bigger? (Currently i use size per data sheet)
- extend PCB pads over the edge of the package?
- have a via in the PCB pads to be able to rework individual pads from bottom side?
- do i need a special solder paste for this?
- other ideas?
Best Regards
Matthias