Understanding the Requirements of a Mass-Imaging Platform with Reference to the Impact of Interconnect Miniaturisation

摘要

As the frontiers of feature size and interspace between devices become ever challenging, we as an industry have to start revaluating the performance of the toolsets that are used in the SMT arena. The days have gone where a tolerance of tens of microns was acceptable; this has now moved into the sub 10-micron domain. This issue is none more critical than within the print process, it is this pre placement tool-set that is most sensitive to the miniaturisation program running through the industry. When we take a step back and reflect on what is required from a printing process at this new level of miniaturisation, we can quickly understand that the solder paste volumes required are crossing into semicon territory. Indeed it is clearly possible to count the solder particles that makes up a 0.3mm C.S.P deposit, the scale is so small. It is therefore paramount the composition of this pre placement tool-set is fully realised. It is the intention of this paper to break down the elements of a print platform into its major mechanical and process subsections. Within the mechanical section, the elements investigated will be co planarity of rail systems and tooling nest; whereas with the process section the elements investigated will be the composition of the squeegee assembly. Each element will be fully explored using analytical methods to comprehend the cause and effects. The separate modules will then be combined to enable an aggregate picture of the process and thus allow a conclusion of which component parts are the most critical and to what level of accuracy is required for the SMT challenges ahead.