We have recently completed the design for a product prototype using the 0.4 mm pitch nRF52832 WLCSP. When we sent it to the board production house, the cost to produce it was exorbitant, particularly when compared with our previous prototype which used the QFN part.
It seems that there are challenges using typical low cost PCB assembly techniques with 0.4mm pitch devices. Yet it would seem that this product is intended for low cost applications. How can we use this form factor and still produce inexpensive devices?
