TECHNOTE
These articles document the impact of Dynamic Runout and the importance of monitoring and controlling it. They are well researched by industry professionals.
Spindle Runout Effects on Positional Accuracy
Don Martin and Robin Wilcox
As presented at the University of Wisconsin ‘Symposium on Small Hole Technology’
Improving drilled hole quality is a continuous process within the printed circuit board industry. The emphasis on small hole and microhole drilling has led management to further study the parameters which can affect quality.
… Because of these limitations, and because a concrete connection between runout and hole quality concerns such as misregistration has never been made, drill room management typically has not closely monitored spindle/collet runout.
… The use of the Lion Precision Dynamic Runout System has changed the situation, allowing the drilling department to accurately monitor spindle/collet runout at operating speeds on the drilling machine.
… The purpose of this paper is to present a study completed at several printed circuit companies which evaluated the impact of runout on registration.
–read this article (600K pdf)-
Dynamic Measurement of High-Speed Spindle Runout:
Determining causes of poor hole quality.
Robin Wilcox
Originally published in PC Fab magazine, March 1989
PCB manufacturers continue to face increased production and quality requirements. Pressure for cost reductions and new emphasis on improved productivity must be dealt with daily. Trends toward tighter tolerance specifications further cloud the picture. In particular, drilled hole diameters are becoming smaller and creating new quality challenges. The following discussion focuses on a critical problem associated with small hole drilling –excessive runout– and what can be done to identify and eliminate the problem.
–read this article (105K pdf)-
Controlling Dynamic Spindle Runout:
How do you measure runout when using a drill bit the size of a hair?
R. J. Darch and C. R. Merrett
Originally published in PC Fab magazine, October 1991
To fully benefit from these improvements in dynamic spindle runout, printed circuit board fabricators must themselves meet two critical requirements. First, careful maintenance of the spindle (in particular, the collet) is essential if the high quality, low runout spindle performance is to be continued in a production environment. Second, in order to consistently monitor dynamic runout over time, it is vital that fabricators adopt the same rigorous disciplines followed by the manufacturer of the spindle.
–read this article (60K pdf)-
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