Fabrication of an LCD light guide plate using closed-die hot embossing

Abstract

Hot embossing is currently applied to replicate microstructures only on one side or two opposite sides of a polymer substrate. If microstructure replication on two perpendicular sides of the substrate is necessary, closed-die hot embossing can be applied. In this study, polymethyl methacrylate (PMMA) was used as the polymer substrate. A closed die with three mold inserts was used to compress a heated PMMA substrate. Effects of related process parameters on the replication accuracy were studied. Closed-die hot embossing was compared with injection molding and injection compression molding. Results show that closed-die hot embossing can provide better replication accuracy. Optical anisotropy induced by the molding-related stresses can also be reduced.

The Influence of Injection Molding and Injection Compression Molding on Ultra-high Molecular Weight Polyethylene Polymer Microfabrication

“…Other than the process parameters, the geometric structure of parts and different polymers is also a factor that affects the melt filling results in lIM (Wu and Chen, 2006;Yao and Kim, 2004;Wu and Lu, 2008;Mönkkönen et al, 2002;Zhao et al, 2003;Yoshii et al, 1994;Yu et al, 2004;Shen et al, 2002;Yu et al, 2002;Shen and Wu, 2002;Su et al, 2004;Saito et al, 2002;. Regarding the process optimization, the melt temperature, mold temperature, (Wu and Chen, 2006;Yao and Kim, 2004) injection velocity and packing pressure (Wu and Lu, 2008) are considered to be the primary factors that affect the part quality in lIM. For different microinjection compression molded parts, the compression velocity (Wu and Chen, 2006) and mold temperature (Wu and Lu, 2008) were the most influential factors in the part quality.…”

“…Regarding the process optimization, the melt temperature, mold temperature, (Wu and Chen, 2006;Yao and Kim, 2004) injection velocity and packing pressure (Wu and Lu, 2008) are considered to be the primary factors that affect the part quality in lIM. For different microinjection compression molded parts, the compression velocity (Wu and Chen, 2006) and mold temperature (Wu and Lu, 2008) were the most influential factors in the part quality.…”

Direct micrometer patterning and functionalization of polymer blend surfaces by using hot embossing

“…on a chip [22][23][24] and devices [25], for polymer replication [26], electrochemical sensors [27] or even to design microfluidic 3D cell culture platforms [28][29][30] that can direct the alignment and proliferation [31], among others [32][33][34]. However, until now the polymers employed for hot embossing have been limited to those commercially available [35][36][37][38][39][40].…”

Effect of a light guide plate with lenticular-arrayed surface on optical output for backlight and illumination application

“…In general, most LGPs have many microstructures on its top, bottom surface, or the both to frustrate TIR to let light emerge from the LGP inside. The various types of the microstructure are formed on the LGP surface by several different technologies such as screen-printing, inject molding, inkjet-printing, hot embossing and etc [7][8][9][10][11]. The inject molding is capable of producing a well-distributed pattern in one pass and has advantage of low cost, high throughput and better optical performance [2,12], so it is widely adopted to formed the microstructures on the LGP, especially for the small to mid-sized LGP.…”