TABLE OF CONTENTS It began with the emergence of the hybrid circuit in the 1960s. The hybrid circuit basically required an expertise that was heretofore totally confined to the semiconductor s back end manufacturing. It was not however a matter simply of copying . This new venture came with its own unique problems that began first with the availability of bare die, and secondly, with the questionable electrical integrity of the die. Available bare die were only minimally tested to specification, limited to wafer probe testing that is basically intended as a screening test only. Thus, a hybrid circuit assembly with multiple die of questionable electrical integrity would run a high probability of failing final electrical testing, resulting in either scraping the part or a reworking . Rework involves attempting to remove defective die and replacing with another die.
The IC manufacturing Back End process covers the assembly, packaging and electrical testing of the IC. Back End processing begins following wafer probe where 100% electrical testing of each IC on the wafer occurs. The testing is to determine nominal functionality and is not at the same level as final package testing.
Defective devices on the wafer are identified by dispensing an epoxy dot (inking) or by storing the location of the device (mapping) in a computer database. Yields on mature product at this point will typically be in the very high 90 s%. The wafer is next mounted on a film for sawing and die singulation (Figure...
