ABSTRACT

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The objective of this chapter is to supplement the strong infrastructure in space

mission quality assurance with information for microelectromechanical systems

(MEMS) and microstructure-related space activity. The generic elements of any

good quality assurance plan apply to the use of microtechnologies in critical and

noncritical space flight applications. The quality assurance plan should be carried

out during the formulation phase of the project. Generic categories of the quality

assurance program include but are not limited to:

. Quality planning

. Design and development

. Change control

. Contractor surveillance

. Receiving, processing, fabricating, assembly, test, and inspection control

. Contamination control

. Metrology and calibration

. Handling, packaging, packing, and storage controls

. Quality records

. Quality audits

. Process improvement

. Software quality

The use of MEMS in space does not have the volume benefits of the commercial

world or the knowledge base seen in space-grade integrated circuits (IC). Commer-

cial production of MEMS devices is a high-volume manufacturing activity where

reliability, efficient process, product characterization, and testing are well defined

from the very earliest development phase up. Elimination of process and design-

related failure mechanisms through statistical analysis and understanding of the

physics of failure yields defect-reduction programs. Successful commercial pro-

grams nurture high yield and profitable, yet reliable production lines.1 In addition,

simulation tools, process-monitoring tools, and advanced characterization tools

are tailored to the product developed.2-5 These tools and process monitors ensure a

reduction in the risk of processing errors, along with an integrated process or

product approach using quality systems and high-volume manufacturing. This is

critical to the production of high-quality products. Unfortunately, a key element

here is volume production, which is not common in most spacecraft applications.

None of the commercial lines in the United States (and perhaps the world) are

developed with the intent to produce space-grade MEMS, and most facilities

(excluding government laboratories such as Sandia National Laboratory) have been

developed to produce MEMS solely for commercial and terrestrial applications.

This chapter will emphasize the noncommercial high volume environment and

assumes that production runs will be an iterative process using prototypes and

small wafer runs. Therefore, the focus will be on custom and prototype activity.