Hi Yoshi,

I recall reading a paper about wet etching soda-lime glass with BOE
where the authors alternated between BOE and HCl in order to dissolve
the stuff that wasn't soluble in BOE (which is basically everything
except the SiO2). They claimed that this improved surface roughness
because the insoluble precipitates would interfere with the BOE etch if
they weren't removed. Here's the info:

A fast prototyping process for fabrication of *microfluidic *systems on
soda-lime *glass*


CH Lin, GB Lee, YH Lin, GL Chang - J. Micromech. Microeng, 2001

good luck,
Joe Grogan

Edward Sebesta wrote:
> Yoshi,
>
>       I can't say if it is smooth enough for your particular application
> since I don't know it. However, it should be fairly smooth. I would etch
> a substrate and then evaluate it through microscope inspection and what
> other inspection tools you might have. If the Pyrex is not homogenous,
> the surface is rough, but I would think Pyrex is homogenous.
>
> Ed