I'm designing a new PCB where I have a whack of connectors that have to line up with the metalwork. These are a two-piece Neutrik XLR connector where the insert is soldered to the PCB and then mates to the shell already mounted on the chassis. There is NO wiggle-room once the insert has been soldered to the PCB - the insert is a sliding fit onto the shell with almost no perceptible side play.
One series of connectors is easy - the solder tab is a thin rectangle. The Plated-Through Hole is perhaps 5 mils larger than the width of the tab and I get great solder adhesion to the flat sides of the tab.
The other series of connectors is more problematic. All 4 pins are round. Thus, I want to have the holes as small as possible while allowing for good solder adhesion over the full length of the pin.
If the exact insert position on the PCB wasn't so important, I'd simply have my usual 10 - 15 mils of clearance. In this case, though, I have 12 to 24 connectors on a single PCB and need to ensure that all of them are as close to the proper location as possible.
I've spent some time with Google and have already looked at some of the guidelines here. Specifically, In pin-through-hole, how much bigger should the hole be than the pin? and In pin-through-hole, how much bigger should the hole be than the pin? and What pad hole (drill) size is appropriate for a given through-hole lead diameter?.
Unfortunately, none of those address the issue of solder wetting and adhesion of component leads in Plated Through Holes in a PCB.
I should mention that we are using 63/37 Tin/Lead solder and that these connectors will be wave-soldered using AZ2331 Water-Soluble Flux.
Our PCB fab house is pretty good when it comes to delivering boards with PTH holes having the correct finished diameter as specified in the drill file.
I'm looking for guidance on how much clearance around the component lead I should have in order to get good solder wetting and adhesion.