Looking at low cost reliable Mother-Daughter board interfaces. Looking at having the Mom w/ a routed out slot, like 1.7mm wide with solder lands on the bottom side then plugging in Daughter thru Mom's slot w/ the Daughter having board edge contacts to align w/ Mom's solder lands on the bottom side. Daughter board would protrude about 1.5mm from Mom's bottom side for wave solder. Our concern is that this product will be outdoors so it will be subject to thermal cycling. We are concerned about realiablity. Looking for advice. Thx.