Adhesive bonding of large surface mounted devices

Wave soldering of large surface-mounted devices requires special adhesives to hold the components position after placement, during transportation, and during the soldering process. The uncured adhesive has to withstand the shear stress on the uncured joint which results from the acceleration and deceleration of the substrates during transportation. The forces acting on components when they are handled are discussed. The friction force, the surface tension, and the yield stress of the adhesive can compensate for the shear stress. Adhesives with a high yield stress, although difficult to prepare and apply, are desirable in large-volume placement equipment