9 November 2010


Peter Wolters’ new slurry halves polishing time for c-plane sapphire substrates

Peter Wolters GmbH of Rendsburg, Germany is introducing a new polishing slurry for the LED market that has demonstrated a 50% reduction in the time required to complete final polishing of c-plane sapphire for flip-chip or through-substrate LEDs (see figure).

Graphic: New slurry reaches surface roughness endpoint in half the time compared to standard colloidal silica slurry.

The development uses a combination of chemical and abrasive technologies to cut the cost of ownership or the manufacturing cost for LEDs when manufactured on c-plane sapphire. “As demonstrated by our testing, the time required to achieve a comparable final surface finish has been reduced by half in substrates of identical incoming quality,” says David Suica, president of subsidiary Peter Wolters of America, the Peter Wolters Competence Center for Sapphire Polishing.

The quality and clarity of the final polished surface is comparable with the use of colloidal silica (which is commonly utilized in the final polishing step), adds the firm.

Peter Wolters says that the slurry product is completely mixed and tested by its in-house team of scientists and engineers to maintain high levels of consistency and quality.

The pre-mixed slurry is shipped in a concentrated form, which can be thinned easily to the appropriate point-of-use consistency by adding deionized (DI) water. Handling and storage of the custom slurry does not require any exceptional processes or procedures beyond what is typical to common colloidal silica.

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