[Pdelcast]

J57:

Wave solder? Is this the 80s?

We use 100% reflow soldering -- there is no wave soldering done. You couldn't wave solder these parts anyway, they are much too small and placed too densely for wave.

The joints look a little grainy because there is a silicone conformal coating over the whole board. Those are beautiful solder joints -- not a cold joint in the bunch.

(Remember, we are 100% lead free, so the solder joints are not as shiny nor as strong as leaded solder joints... but we have no voiding, and 100% of the solder joints are inspected by AOI prior to conformal coating. -- We are lead free because we sell worldwide, and we cannot sell items containing lead in Europe...)

The joints in the picture failed, not because of poor joints, but because of shock. I imagine (even though we didn't see the parts) that the end caps on the inductor failed, the part rotated, and tore the solder joints cleanly. It's pretty obviously a torn joint. A cold joint would have shown voids, not a cleanly torn surface.

Shock can be enormous in these cars -- I've seen 10ga wires ripped in half just from their own weight (think about how many Gs that is!!), 96 mil thick FR-4 circuit boards bent 90 degrees, circuit boards where EVERY pad on one side of the board is torn off the FR-4... you name it, we've seen it. (And 8Gs is nothing... We routinely see forces over 70Gs in RC cars.)

So soldering is very important to us. We use a Heller 7 zone full convection oven (accurate to +- 1 degree in every zone, and specifically designed for lead-free operation), and we profile every batch. We use a very sophisticated AOI system that literally inspects every single solder joint on every single board we produce.

We use a VERY expensive tin/copper/silver solder formulation for our solder paste (printed,) bar solder and wire solder. This is a much stronger (physically) formulation than SN100 (100% tin) which is used in most lead-free industries today. It's still not as strong as 60/40 -- but it's close.

We take quality very seriously -- we aren't perfect (see MMM V1...), but we utilize tools that make the quality easy to maintain, and we check our quality continuously.

Castle isn't a basement operation - - we have some of the most sophisticated equipment in the world in our surface mount line (including the fastest and most accurate chipshooter available today), and we produce around 30,000 controllers a month.