Effects of chemical components on the bending properties of micro-sized cantilevers in three types of SU-8

Bending tests were performed using micro-sized cantilever specimens in three different types of epoxy-based photoresist, SU-8 (i.e. SU-8, SU-8 2000, abd SU-8 3000) to clarify the effects of the chemical components on the bending properties, especially focused on the solvents and/or the additive. Gamma-butyrolactone (γ-BL) is contained as solvent in SU-8; in contrast, cyclopentanone is used in both SU-8 2000 and SU-8 3000. The additive is contained in SU-8 3000 only. The bending properties such as Young’s modulus, Yield stress, and bend strength are similar between SU-8 and SU-8 2000; although the solvents are different between the resists. The result shows that the effects of these solvents on the bending properties are little. On the other hand, the Yield stress and the bend strength in SU-8 3000 are lower than those in the others. In addition, the micro-sized cantilevers in SU-8 3000 behaved in a ductile manner during the bending tests, although the other SU-8s behaved in brittle manner. It is suggested that SU-8 should be made softer by the additive, which is a kinds of aliphatic compound.

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► We perform bending tests using micro-sized specimens in three different type of SU-8.
► All the SU-8s is similar in Young’s modulus.
► The SU-8s, which include different solvent, are similar in the bending properties.
► The SU-8, which added some additive, behaves in a ductile manner.
► The additive should make SU-8 softer.