Coefficient of Thermal Expansion Measurement Case Study
The following example illustrates a typical material coefficient of thermal expansion test using the Analysis Tech CTE Tester. The material tested is a yellow silicone material of the type commonly used in electronic packaging. This material was subjected to a total temperature span of 70°C in two discrete temperature 'bands' (25°C to 60°C & 60°C to 95°C). Steady-state thermal equilibrium was attained at each temperature 'step' (25°C, 60°C, and 90°C), with the temperature and linear displacement measured and recorded between each temperature plateau.
The software generated a plot of Displacement vs Temperature showing the change in total material length at each temperature, and generated a plot of Displacement vs Time showing that the material had sufficient time to reach steady-state thermal equilibrium at each temperature.
The overall coefficient of thermal expansion (CTE) value for this sample, from 25°C to 95°C was 184.9 x 10-6/°C (μ-inch/°C).
CTE-360 Example Test Data
[CTE-360 Test Summary #1]
Sample ID= Yellow Silicone
Sample Length= 2.015 inches
Raw Data File= 177-15-23-x1_CTE.dat
CTE: 1=25°C to 95°C: 184.9 x 10-6/ °C +/- 3.2%
CTE: 2=25°C to 60°C: 184.0 x 10-6/ °C +/- 3.5%
CTE: 3=60°C to 95°C: 185.8 x 10-6/ °C +/- 3.5%
Date/Time= 03-21-2016/19:41:17 S/N:1160220 WinCTE V1.0.0