Mumbai University > Electronics Engineering > Sem 8 > MEMS Technology

Marks: 5M

• TCE [Thermal co-efficient of expansion] : The co-efficient of thermal expansion is defined as the fractional increase in the length per unit rise in temperature.

• Usually, TCE is specified over a temperature range because it varies depending on the temperature.

• The equation below describes a linear thermal expansion

  $\frac{ \triangle L}{L} = \alpha_L \triangle T$

  where, $\triangle L$ = change in length

  L = original length

  $\alpha_L$ = Linear co-efficient of thermal expansion

  $\triangle T$ = change in temperature.

Issues related to TCE :

1. The TCE is often not the same in all axes. In MEMS structure the values are different X and Z plane.

2. TCE , it is rarely linear and should be quoted either at a specific temperature or an average over a given temperature range.

3. The variation in TCE with temperature is only a fairly smooth function if the material is undergoing no phase transitions.

• TCE [Thermal co-efficient of expansion] : The co-efficient of thermal expansion is defined as the fractional increase in the length per unit rise in temperature.

• Usually, TCE is specified over a temperature range because it varies depending on the temperature.

• The equation below describes a linear thermal expansion

$\frac{ \triangle L}{L} = \alpha_L \triangle T$

where, $\triangle L$ = change in length

L = original length

$\alpha_L$ = Linear co-efficient of thermal expansion

$\triangle T$ = change in temperature.

Issues related to TCE :

1. The TCE is often not the same in all axes. In MEMS structure the values are different X and Z plane.

2. TCE , it is rarely linear and should be quoted either at a specific temperature or an average over a given temperature range.

3. The variation in TCE with temperature is only a fairly smooth function if the material is undergoing no phase transitions.

The chemical compound trichloroethylene is a halocarbon commonly used as an industrial solvent. It is a clear, colourless non-flammable liquid with a chloroform-like[1] sweet smell. It should not be confused with the similar 1,1,1-trichloroethane, which is commonly known as chlorothene.