BMM350 Welding Yield Too Low

[YeezB]

I am trying out the BMM350 IC for the design of an open source hardware for creators and personal developers.
However, during sample production, the BMM350 is experiencing low yields when it is patched onto the PCB. (Only one of the four samples worked, the other three had varying degrees of solder distortion.)
It appears that the BMM350 package is too small and the BGA package pins are too tight causing this.

We used Altium Designer to generate the package by entering data from the specification.
The package PCB has no vias, and the board is a gold immersion process.
The sample was produced with a stencil size of 0.1mm.

We consulted with a senior PCB layout engineer, who gave the advice to reduce the amount of solder used during production.
Is there any other suggestion to improve the soldering yield other than this one?
Thanks in advance.

[FAE_CA1]

Hi,

Thanks for your inquiry.

Please refer to Section 5 and 6 in the BMM350 handling, soldering and mounting instruction document at https://www.bosch-sensortec.com/media/boschsensortec/downloads/handling_soldering_mounting_instructi... for more information.

Thanks.