Photoresist epoxy-based

What is the developer solution used for the photopattemable epoxy-based photoresist (SU-8) [236,271,748,762] (2 marks)... 

Photoinitiated cationic polymerizations have numerous applications involving photoimaging. Epoxy-based photoresists with high resolution derived from commercially available resins have been developed (22) and the use of these same materials in plastic flexographic printing plates has been shown in our laboratory. 

The comhination of conventional photolithography and photoresist reflow is an effective method to smoothly integrate microfluidic chamhers with microchannels. To fabricate a PDMS 3D microstructure joined with the microchannel by mold transfer, a master mold is needed. The photoresist reflow method was adopted to make the master mold for the 3D chambers and a negative photoresist SU-8 was used to generate the microstructure master mold for the microchannels. Since SU-8 is an epoxy-based photoresist and has good chemical stability with stands... 

The most popular polymers used to fabricate lab-on-a-chip structures are polyfdi-methylsiloxane) (PDMS), polyfmethyl methacrylate) (PMMA), high-density polyethylene, low-density polyethylene, polyamide 6, and the epoxy-based photoresist SU-8 (Becker, 2002). Particularly, PDMS has been widely reported for miCTofluidic systems because it has many favorable properties for prototypes fabrication the material is inexpensive, optically transparent to visible Ught, which makes it compatible with optical detection systems, and also biocompatible its molding procedure is safe and easy to learn and its flexibility allows the integration of elastomeric actuators and optical elements into devices. 

Figure 5.2 Image of a nib structure (first generation) fabricated in the epoxy-based negative photoresist SU-8 and supported on a silicon wafer (scanning electron microscopy). (Reprinted with permission from Ref. 11).

Although the silicon micromachining process is well developed, extensive use of costly clean-room instrumentation is required. Thus, alternative and simpler template construction approaches are being pursued. One such method utilizes SU-8, an epoxy-based negative photoresist, which has excellent chemical resistance and mechanical properties. Patterned SU-8 is being applied increasingly in making microstructures for templates in microchip production... 

The photoresist SU-8 is an epoxy-based photosensitive polymer that loses its resistance to chemical etching when exposed to ultraviolet radiation. It is used especially in the transference of a structure pattern to a substrate. It offers properties such as high mechanical strength,... 

Cho J-D, Ju H-T, Park Y-S, Hong J-W (2006) Kinetics of cationic photopolymerizations of UV-curable epoxy-based SU8-negative photoresists with and without silica nanoparticles. Macromol Mater Eng 291(9) 1155-1163... 

A popular resist for MEMS processing is SU-8 [US Patent No. 4882245 (1989)]. This is a negative tone resist and is commonly applied as a layer, tens of micrometres in thickness. SU-8 was developed by Shell Chemicals and uses epoxy-based chemistry. Microchem [www.microchem.com] is one of the companies that now holds the licence for production and sale of SU-8 photoresists. 

Figure 4.42. Molecular structures and photoinduced reactions of common photoresists. Shown are (a) the diazonaphthoquinone (DNQ) positive tone photoresist, and (b) the SU-8 epoxy-based negative tone photoresist.

The majority of 2-methylphenol is used in the production of novolak phenoHc resins. High purity novolaks based on 2-methylphenol are used in photoresist appHcations (37). Novolaks based on 2-methylphenol are also epoxidized with epichlorohydrin, yielding epoxy resins after dehydrohalogenation, which are used as encapsulating resins in the electronics industry. Other uses of 2-methylphenol include its conversion to a dinitro compound, 4,6-dinitro-2-methylphenol [534-52-1] (DNOC), which is used as a herbicide (38). DNOC is also used to a limited extent as a polymerization inhibitor in the production of styrene, but this use is expected to decline because of concerns about the toxicity of the dinitro derivative. 

Figure 1 shows a schematic representation of the polymer network obtained by laser curing of a photoresist based on a bis-phenol A epoxy-... 

The Kodak photoresist based upon the poly(vinyl cinnamate) system is particularly suitable for printed circuit manufacture. It also finds application in some invert halftone photogravure processes and photolithographic plates. The property of superior adhesion to metal of cinnamic esters of particular epoxy resins has resulted in the preferred use of these resins for platemaking. Very few of the cinnamate-type resists have, however, been used in micro applications. 

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