SCHOTT Borofloat 33 Nexterion Glass B Flatness and

SCHOTT Borofloat® 33 / Nexterion® Glass B Flatness and Surface Quality

SCHOTT Borofloat® 33 / Nexterion® Glass B n Borofloat® 33 is a flat, borosilicate glass n Borofloat® 33 is manufactured using the “microfloat” method n The production method produces virtually flawless flat glass and a mirror -like surface quality

Many Parameters Influence Glass Sheet “Flatness” n Surface Flatness is the deviation for a plano surface n Warp is the difference between the maximum and minimum deviations of the median surface relative to the backside reference plane. Warp is like the wavy deformation seen in potato chips. n Bow is the measure of how concave or convex the deformation of the median surface of the glass sheet at the center point, independent of any thickness variations. The easy way to visualize Bow is if you think of a bowl turned either upside down or right side up on a flat surface (convex or concave). n Total Thickness Variation (TTV) represents the difference between the minimum and maximum thickness measured on the sheet of glass. n Thickness Tolerance (inter-slide) The production of large flat sheets of glass yields variances in thickness. Thickness will vary depending on sheet size and where on the sheet the measurement is made. In order to accommodate this fact SCHOTT uses a nominal tolerance value n Thickness deviation (intra-slide) This is the thickness differences between slides n Surface Roughness Smoothness: RA (average roughness) or RMS (root mean squared) is a measure of the texture of a surface.

Bow and Warp

Total Thickness Variation (TTV)

“Flatness” of Nexterion® Glass B Slides Ø SCHOTT Nexterion® defines “flatness” as the accumulated overall possible thickness deviation Ø This includes warp, intra-slide thickness deviation, and interslide thickness tolerance Thickness deviation intra-slide Thickness tolerance inter-slide Ø Nexterion® slides have a maximum total “flatness” deviation of ≤ 25 µm for these three factors combined