Fabrication of thick electroforming micro mould using a KMPR negative tone photoresist

Abstract

The microfabrication of thick electroforming micro moulds using a KMPR negative tone photoresist has been investigated. SU-8 resist is currently the most widely used thick resist for electroforming masking, but difficulties in removing crosslinked SU-8 have considerably limited its applications in microelectroforming applications. KMPR resist is a complement to SU-8 in providing electroforming moulds. A considerable advantage of KMPR compared to SU-8 is that it can easily be removed after completion of electroforming using commercially available chemical removers. In the characterization of KMPR for making microelectroforming moulds, an optimized double spin lithography process using an UV mask aligner has been developed. The process enables the KMPR moulds to have dimensional accuracy and sidewall verticality comparable to those of SU-8. Structures of 180 µm in thickness and aspect ratio of 18:1 have been fabricated repeatedly in experiments. Microelectroforming was conducted in the KMPR moulds and the results show excellent geometry. The KMPR moulds were easily stripped without damaging the metal components or leaving residues around the metal structures. KMPR resist was also successfully stripped from confined areas, such as nickel channels of 180 µm thickness and 40 µm width.

Reliability aspects of a radiation detector fabricated by post-processing a standard CMOS chip

“…KMPR is an epoxy based I-line photoresist that can be more easily stripped than SU-8 [11]. Additionally it allows for shorter processing times due to the lower amount of solvents in the material compared to SU-8 allowing for shorter bake steps.…”

Threefold Diffusion Layer Model for One Kind of Pulse Reverse Nanoelectroforming

“…The inherent advantage of electroforming, such as high dimensional precision, accuracy of reproduction and production of thin-walled components, attract researchers to solve the problems of this technology encountered in a very wide range of applications and industries, 1-6 including a radical new developing area called nano electro and mechanical system (NEMS). [7][8][9][10][11][12][13] Nanoelectroforming is the preferred method of manufacture, and many other instances where it is the only choice that can be used to produce a particular nanostructure. 14 15 Electroformed nanostructures, such as metallic nano stamps, nano molds, and nano hole arrays, have been produced.…”

Production of high-precision micro metallic components by electroforming process

“…Electroforming is widely employed to successfully produce micro components of metallic materials [18] and careful control of the deposition rate of the metallic ions during the electroforming process can allow the formation of micro components with extraordinarily high precision [19]. In particular, the precision of the micro components is closely associated with that of the mould.…”