微流体制造

在工艺开发过程中，重点是快速灵活地制造少量微流体设备原型，以供评估。在最终确定装置的设计之前，要对制造能够达到性能要求的装置进行 "概念验证"，并对产品设计、测试和优化进行多次反复。由于微流体设备的设计参数通常会在这一阶段发生变化，因此直接加工或激光制造方法比昂贵、高产能但灵活性较差的模具制造工艺更受青睐，前者可快速调整特征尺寸。直接加工方法还可以制造部分芯片设计，从而加快制造速度，并能快速筛选包括微通道和支柱在内的困难特征。 工艺开发的主要目标是在放大之前确定应用中设备的正确设计规格。因为在这一阶段，设计参数的变化是很常见的，所以灵活性和制造速度是最重要的。 原型器件完成后，Potomac 可以对其进行加层、粘接盖板和钻孔。

扩大规模的目标有两个，首先是增加产量和降低单位成本，其次是开发将工艺扩大到商业产量所需的技术诀窍。对于以聚合物为基础的微流控设备，热压印和注射成型等基于模具的工艺是常用的技术。然而，要为微流控器件开发有效的放大解决方案，就必须了解集成微制造系统，其中不仅包括上述复制工艺，还包括粘接、表面处理和接口连接等复制后操作。此外，还需要了解微制造的经济性，特别是单位成本与产量之间的关系，这对何时从批量操作过渡到连续操作，以及从一种复制技术（如热压印）过渡到另一种复制技术（如微注塑成型）具有关键性的决定作用。为了做出这些关键决策，我们开发了一个技术经济模型，使工程师能够对不同的生产方案进行敏感性分析。 许多工程师都犯了一个错误，即认为过渡到更高产量的复制技术会自动降低单位成本；事实上，最低单位成本通常由微细加工系统的其他工艺决定，如粘接、表面处理和互连。最经济的微加工系统会根据所需的制造量匹配适当的制造技术，消除工艺中的 "瓶颈"，根据经验法则，设计良好的系统在放大后，设备的单位成本可望降低一个数量级。 设计精良的微加工系统还能在生产需要时顺利过渡到更大批量的技术。

A critical objective of scale-up is to design the microfabrication system for commercial volumes and the integrated microfabrication system should be designed to deliver the microfluidic product at the minimum unit cost for the specified volume.  Equally important is that the system be designed to allow for scale-up to larger volumes once product demand increases. As mentioned above, this can only be achieved with a thorough analysis of the microfabrication system that provides insight on how the individual operations impact the integrated system at different production volumes as well as a cost model that models the unit cost as a function of production volume.rnrnu003c/divu003ernu003cdivu003eThe purpose of technology transfer is two-fold; to transfer the commercial microfabrication process defined during scale-up to manufacturing and secondly to develop the Process Technology Package (PTP) for future scale-up when production volumes increase. Technology transfer to manufacturing first and foremost entails developing the standard operating procedures (SOPs) for each operation of the microfabrication system. In addition, it entails training operators and technicians to achieve the Key Performance Indicators (KPIs) that include quality control, yield and cycle time repeatably and consistently. As a rule of thumb, you can expect that at the conclusion of technology transfer the unit cost will be further reduced by a factor of 2 or greater. Eventually the scale of the microfabrication system may need to increase to accommodate increasing demands for your product and with proper foresight the system will have been designed to enable a smooth transition to higher volume manufacturing. Development of a technoeconomic model for the microfabrication system as described above will enable you to anticipate in advance the next generation of technologies that will be required and the current processes that will need to be optimized in order to further scale-up manufacturing. Using this insight, microfabrication engineers can customize the development effort to collect relevant data for that purpose during the scale-up phase. This data would become an integral part of the Process Technology Package for use when production requirements increase.