Andy, We developed a polishing process for a back-emitting VCSEL after thinning wafers to <80µm. Our polish was better than 80Å Ra. Handling them after demount was brutal. Brad Cantos brad.cantos@holage.com http://holage.com On Jan 21, 2010, at 7:23 AM, Andy Irvine wrote: > Thanks Brad and Brent for some good ideas. I guess mechanical is the way to go - I can access the right sort of grinding sludge. > > Brad - if you managed that, I take my hat off to you! > > Cheers all, > > Andy