  During electrostatic bonding, also known as anodic bonding, silicon is bonded
to glass by applying an external voltage and simultaneous heating to
temperatures of 200...450 $\deg$C. While cooling to working temperature after
bonding happened pieces are mutually deformed. Due to linear thermal expansion
coefficients mismatch of anodically bonded glass and silicon samples an
internal stress state is generated. Such stresses are called thermal mismatch
stresses. The aim of this paper is a determination of technological and design
solutions to achieve minimal thermal mismatch stresses in resulting bond.
  The nonlinear dependence of linear thermal expansion coefficients of bonded
samples' materials on temperature makes it difficult to minimize thermal
mismatch stresses by chosing materials with close average thermal expansion
coefficients in particular temperature range. To assess means of lowering
thermal mismatch stress in this paper two different ways to describe assembly
are used: two thin bonded layers and multilayered composite material.
  Based on properties of two brands of glass (LK5, Borofloat 33) and silicon
used with described mathematical models thermal mismatch stresses at
temperature $T_w$ in samples bonded at several different temperatures $T_b$ are
evaluated. Bonded silicon surface stress dependence of glass to silicon wafer
thickness ratio is evaluated. Based on such evaluations one can say that by
varying thickness of glass bonded to silicon one can obtain zero thermal
mismatch stress at a particular depth of material or obtain stress of some
defined value at this depth.
  Models of assembly description used in this paper can be used to optimize
anodic bonding process parameters. Such usage aimed to minimize thermal
mismatch stresses at device working temperatures is presented in this paper.
