So, we�re talkin� �bout the smaller end of a "large" paper clip after it�s unfolded once, eh?
In keeping with your "nothin� up the sleeves" full disclosure, I�ll bet you�re feelin� a little sheepish about not tellin� us about: * Antenna pad dimensions, quantity, and location [relative to the antenna] * Results of the reduced blower volume on the SOT23 near the bent-up paper clip thingie * Effect on reflowing other SOT23 packages * Reflow profile, other than letting us fantasize what it would be using a NC paste
I hear you talkin� �bout the blowers pushin� the antenna off its pads and that makes sense [even tho you didn�t tell us, the bent-up paper clip thingie has to be soldered with two pads at the top of the U shape, because the pads have to be small, the U would the relatively long, the U would not be secured at the bottom of the U] because:
1 Bottom of the U acts like a long lever that pivots at the top of the U.
2 Alternately, the "arms" of the upper part of the U could be spreading apart during heating and then closing after the reflowed solder has cooled.
But then I hear you talkin� �bout the blowers pushin� every tenth antenna off its pads and I wonder why every tenth? Why not all of them? Yano, �cause the fans are turned-on, crankin� and doin their thing aren�t they? Could it be that
1 Blowers don�t blow at a constant volume, even though they are set at a constant rate, because they get behind [or ahead] on cooling , then need to crank up [or down] the volume every ten boards? [Didn�t someone like Glenn Campbell do a song about "cranking-up the volume"?] So as the oven compensates by firing-up the blower ever ten boards, it then blows the antenna from its pads. Coo, eh?
2 This could still be explained by the thermal expansion theory [#2 above] if the oven gets real hot to spread the legs [hey, hey, this is a family show, watch it!!!] of the U, get poor reflow bla, bla, bla AND just after that the fan kicks it up a notch [as Emeril says BAM!!!], but not such a high notch to dislodge the paper clip thingie on the next board.