02/13/2013 Manufacturing Engineering Magazine Interview with Donna Bibber, January 2013 issue:
Micro components continue to shrink in size demanding ever greater precision and improved handling of parts with sub-micron-sized features. New approaches in micro-machining technology include higher precision systems from traditional micro-machining developers, as well as techniques using additive manufacturing processes semiconductor wafer scale technology on the smallest of micro-parts. With micro-machining in molding techniques, manufacturers can create an astounding array of extremely small parts for medical uses including catheters, surgical tools, and implants made from a variety of materials including metals, ceramics, silicon and PEEK polymers. Micro components also increasingly power the latest high-tech devices with the small batteries, connectors, LEDs and IC chips found in smartphones and iPads, and some of the tiny devices being used in aerospace and defense applications by the military.
“The industry is definitely getting smaller and smaller, in terms of the size of the component, and the precision of the components they require. We are approaching nano in feature size and tolerance, and the envelope is being pushed further in that direction every day,” said Donna Bibber, president and CEO of Micro Engineering Solutions (MES Charlton City, MA), a manufacturer and developer of micro-machined and micro-molded parts.
Metrology, Part Handling Obstacles
As micro components become smaller and more precise, manufacturers face more difficulties in combining materials, which can be either metal or plastic pieces, to make an assembly, Bibber noted. Problems can also arise in measuring and testing sub-micron parts. ”The testing and the metrology is as important as anything,” she added. “You probably heard the saying ‘You can’t make it if you can’t measure it.” At this level of small, that is even more important.”
A recent MES project involved making an endoscope measuring 5mm in diameter by 20mm long in which there are 18 different metal components working together, so the endoscope can move and rotate a needle 360 degrees, Bibber recalled. “You can imagine how much of the stack up tolerance, literally microns, in this instance,” she said. “We can’t always scale up to the tolerance needed from machined parts to molded parts, but we have a plan for scale up from part one in terms of stack up tolerances.”
Another major issue is the trend toward more challenging part geometries. “The trends are small features, small parts, and small assemblies,” Bibber said. “The challenges are mostly in handling, and metrology. The bulk of the cost of the assemblies are really in how you handled the components, and how they are measured.”