64 results about "Quad Flat No-leads package" patented technology

A thin quad flat no-lead (QFN) package method comprises the following steps of: adopting a first coating substance (plastic package material) to be coated on a first surface (the back) of a wafer and form a continuous covering layer; cutting the wafer into a plurality of discrete semiconductor crystalline grains, each of which has the covering layer cut down from the continuous covering layer on the surface; mounting the covering layers of the plurality of discrete semiconductor crystalline grains on the surface of an adhesive film on a frame; after wire welding (lead bonding), adopting a second coating substance (plastic package material) to be coated on an exposed surface above an adhesive surface, and the second coating substance wraps together the semiconductor crystalline grains mounted on the adhesive surface to form a whole block of plastic package body; and cutting the whole block of plastic package body and obtaining a plurality of discrete completely packaged semiconductor crystalline grains (devices with complete functions). With the advantage that all the package processes have no special requirement on the structure of packaged chips, therefore the package method has universality, and besides, the device obtained by using the package method is very thin, thus being beneficial to improving the heat dissipation efficiency of chips.