Packaging represents a significant and expensive obstacle in commercializing microsystem technology (MST) devices such as micro-electro-mechanical systems (MEMS), micro-optical-electro-mechanical-systems (MOEMS), microsensors, microactuators and other micromachined devices. This paper describes a novel wafer level protection method for MST devices which facilitates improved manufacturing throughput and automation in package assembly, wafer level testing of devices, and enhanced device performance. The method involves the use of a wafer-sized micro-cap array. This array consists of an assortment of small caps molded onto a material with adjustable shapes and sizes to serve as protective structures against the hostile environments associated with packaging. It may also include modifications which enhance its adhesion to the MST wafer or increase the MST device function. Depending on the application, the micro-molded cap can be designed and modified to facilitate additional functions, such as optical, electrical, mechanical, and chemical functions, which are not easily achieved in the device by traditional means. The fabrication method, materials selection, and the compatibility of the micro cap device to conventional packaging process are discussed in this paper. The results of wafer-level micro cap packaging demonstrations are also presented.
Microfluidic networks suitable for biomedical applications have been fabricated in a variety of polymer materials using micromolding and lamination. By molding several layers of 2D microfluidic patterns in a variety of materials, then laminating together, a wide variety of complex 3D systems with micron sized resolution can be constructed. The process of micromolding and lamination, and the integrated fabrication process for biomedical microfluidic devices is presented. Emphasis is on the practical aspects of fabricating fluidic prototypes in the research laboratory.
Cast molding is a simple, low cost microfabrication method which offers the potential to fabricate microstructures in a large variety of polymer materials. We discuss some characterizations of a cast molding technique which exploits the use of polydimethylsiloxane as a mold material. The suitability of this process for microfluidic systems with five different polymers was studied by observing the mold sticking properties, pattern transfer resolution, and effects on surface roughness and surface wettability. The process yielded excellent results for all polymers, suggesting the suitability of cast molding as a general purpose microfabrication technique for polymers. Surface wettability was modified for some polymers.