Precision heating appts. with removable hot plate - used e.g. for soldering or adhesive bonding of articles, has structure which contains heating elements and coolant passages

摘要

An article heating and cooling appts. comprises a sub-structure (12), which contains heating elements and coolant passages and which is in thermal contact with a removable hot plate (18) for supporting the article, and an article temp. sensing device which produced electrical signals used by a controller for controlling electrical supply to the heating elements (14) and coolant flow rate through the passages (16) to produce a predetermined hot plate temp. profile. A novel hot plate (18) comprises (i) a weight system (70) for holding articles in a stationary position during mounting or removal of the hot plate (18) on or from the sub-structure (12); (ii) a plate (18) with article holding locations; and (iii) an array of weights above the article holding locations, each weight being freely displaceable between a lowered position, in which the weight rests on an article held on the hot plate (18), and a raised position, in which the weight is raised above the article. USE/ADVANTAGE - The hot plate is used for heat treatment such as pore-free fusing or soldering of semiconductor wafers to electronic components or assemblies, soldering or low temp. braze sealing of small electronic components or units, and bonding of parts or flat laminates with epoxy resins or adhesives. The plate portion can be removed after heat treatment to allow mounting of another plate portion holding other articles so that treatment throughput is significantly increased. The articles are precisely positioned on the plate and can be held in position on the plate during subsequent process steps.