In an Injection Molded Soldering system, a single, one-layer decal has one or more through hole patterns where each through hole pattern has a plurality of through holes through the decal. A drum with a drum circumference turns while the decal is forced to be adjacent to the drum circumference. The decal passes by a tangent point on the drum circumference where one or more solder-filled through hole patterns align with recessed openings on a substrate at the tangent point of the drum circumference. Applied heat causes the solder structures to melt and flow into the recessed openings.