Achieving Conrolled Reflow

摘要

High and uniform heat transfer is the foundation capability of any reflow oven. It's almost always demonstrated by establishing a profile on a thermally complex product and measuring temperature uniformity across the entire board, especially at peak temperature. Another criterion is the capability of a reflow oven to generate the desired profile shape on various boards. Although most process engineers would prefer to use a straight ramp profile, sometimes a form of ramp-soak-spike profile improves thermal uniformity of complex products, or a shoulder profile reduces defects, especially tombstoning. Accurate control of profile shape is achieved within an oven through zone definition.