Method for improving the flatness of glass disk substrates

A method for improving the flatness of nonmetallic disk substrates, said method comprising the steps of:

• (a) placing the substrate on a support, said substrate comprising a first material, said support comprising a second material;
• (b) heating said substrate to within the annealing range of the first material for a period of time effective to remove stresses within the first material;
• and
• (c) controllably cooling said substrate and said support so that said first material and said second material cool at a substantially equivalent rate.

A method for improving the flatness of a glass disk, said method comprising the steps of:

• (a) mounting said glass disk on a support, said support comprising a refractory metal;
• (b) heating said glass disk to at least about 500.degree. C. for a period ranging from about 0.5 hours to 12 hours;
• and
• (c) controllably cooling said glass disk and said support so that said disk cools at a rate of about 0.25.degree. C./minute to 1.5.degree. C./minute to room temperature.

A hard disk memory element resulting from a method comprising the steps of:

• (a) mounting said glass disk on a support, said support comprising a refractory metal;
• (b) heating said glass disk to at least about 500.degree. C. for a period ranging from about 0.5 hours to 12 hours;
• and
• (c) controllably cooling said glass disk and said support so that said disk cools at a rate of about 0.25.degree. C./minute to 1.5.degree. C./minute to room temperature.