Blowholing in PTH Solder Fillets

For a given batch of printed circuit boards of a particular quality and with a particular level of moisture absorption, the parameters of a wave soldering machine may be tuned to minimise the amount of visible blowholing. This paper shows the inter‐relationships of blowholing with other soldering faults such as icicling, bridging and poor pull‐through. The inter‐relationships result from adjusting each machine parameter in turn. This is important since blowholing cannot be minimised without regard to these other effects. The effect of the quality of the printed circuit boards on the response to machine parameters is predicted from a model, and measurements are found to be in agreement with the predictions.