Parts are routinely held in WIP while test attempts to handle the influx and myriad of new packages, device types, speed and newer combined fab technologies. New, more expensive testers and handlers may actually reduce throughput, further increasing costs. The handlers ended up costing two to three times more than the older gravity feed handler and are as much as ten times slower in index times. Wafer fabrication advances are of singular immensity. The introduction of 300 mm wafers and 0.15-micron linewidths will allow staggering density and capacity increases.
Assembly continues to increase density of packages and reduced pitches.
The strips and lead frames are increasing in size, adding even more capacity by processing larger quantities of parts in a single operation. But test continues to get slower and more expensive. The first real evaluation and production proofing of strip test was done initially by Motorola Austin and has since been supported and initiated by NSC, Amkor and others. This results in lower costs, reduced cycle times and improved quality, all demanded by test engineers. The almost total lack of communication and cooperation between assembly and test has caused most test handler companies great frustration.