> Mechanical Properties

Tensile test

Research background

Mechanical properties of thin films are fundamental factors to evaluate and improve mechanical reliability of various devices. However, it is very challenging to conduct tensile test of thin films. Our lab has developed adequate tensile testing systems for diverse thin materials. Exact mechanical properties such as elastic modulus, tensile strength and elongation are measured by using several tensile testing methods.

Bending test

Research background

Bending properties of various materials in flexible devices are critical because they undergo frequent bending deformation in their applications. Three-point or four-point bending tests are utilized to measure the flexural properties including flexural modulus and flexural strength, which directly represent the mechanical response of the materials under the bending such as warpage.

- Flexural modulus of thin composite laminates (FR4 substrates)

- Modulus of thin films with film-on-substrate structure

- Chip-embedded flexible package


Research background

The coefficient of thermal expansion (CTE) is an important material property that indicates the dimensional stability of a material under temperature variations. The CTE should be accurately measured to predict thermal stress that develops in a electronic package during its thermal fabrication or the usage at high temperature. We utilize digital image correlation (DIC) method for precise strain measurement in a non-contact manner. This method is applied to most of the engineering materials ranging from low CTE ceramics to high CTE elastomers. The optical strain evaluation method also imparts high-throughput measurement.

- Non-contact, high-throughput CTE measurement

- CTE of very soft elastomers

- Low CTE of GFRP laminates