Concave microlens array mold fabrication in photoresist using UV proximity printing

Lin, Tsung‐Hung; Yang, Hsiharng; Chao, Ching‐Kong

doi:10.1007/s00542-006-0264-2

Cited by 20 publications

(8 citation statements)

References 19 publications

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“…The data are calculated using Eqs. (1)- (10). The factor effect plots of optical coupling efficiency on control factors are shown in Fig.…”

Section: Optimization Results and Discussionmentioning

confidence: 99%

“…The depth h in the concave photoresist mold microlens is always about 3.5 μm for various diameters. The curvature radius Rc of the concave photoresist mold is dependent on the round pattern of the mask and printing gap (gap) and can be expressed as [10] Rc…”

Section: Theoretical Modeling and Formulationmentioning

confidence: 99%

“…The master concave photoresist mold was used to fabricate PDMS semiellipsoid microlens. PDMS microlens arrays have been fabricated using a replication molding technique [10]. A PDMS microlens with variable focal lengths was developed by liquid-filling a cavity [11].…”

Section: Introductionmentioning

confidence: 99%

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Semiellipsoid microlens fabrication method using UV proximity printing

Hung

Shen

et al. 2012

Appl. Opt.

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We present a new semiellipsoid microlens fabrication method that controls the printing gap in the UV lithography process without thermal reflow. The UV proximity printing method can precisely control the curvature radius ratio of the semiellipsoid microlens in the fabrication process. The proposed fabrication method facilitates mass production to achieve a high-yield and high-coupling semiellipsoid microlens that is suitable to be used in commercial fiber transmission systems. A semiellipsoid microlens can be tipped on a single-mode fiber end to improve power coupling efficiency from laser diodes. The semiellipsoid microlens allows increasing the fiber spot size and numerical aperture. It is very important to control the geometric parameters in the assembly procedure to increase the optical coupling efficiency between the laser diode and single-mode fiber. Wide misalignment tolerance, low loss, and low manufacturing cost could be achieved by the proposed fabrication method. The theoretical model is first developed to predict the optical coupling efficiency for various microstructure geometries of semiellipsoid microlens and assembly parameters in this study. Then, the Taguchi method is applied to obtain the optimal geometric parameters setting. The results show that optical coupling efficiency could be significantly improved by using the optimal geometric parameters setting.

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“…The data are calculated using Eqs. (1)- (10). The factor effect plots of optical coupling efficiency on control factors are shown in Fig.…”

Section: Optimization Results and Discussionmentioning

confidence: 99%

Section: Theoretical Modeling and Formulationmentioning

confidence: 99%

See 1 more Smart Citation

Semiellipsoid microlens fabrication method using UV proximity printing

Hung

Shen

et al. 2012

Appl. Opt.

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“…Unfortunately, most of these methods are not suitable for direct fabrication of negative or concave lens arrays. In the past, only a few technologies have shown the potential to fabricate concave lens array, such as UV proximity printing technique [10], 3D diffuser lithography [11], combined of thermal reflow technique and PDMS replication process [12], laser-enhanced local wet etching process [13], isotropic etching of glass master [14]. Nevertheless, the preceding literature survey shows that most of the fabrication techniques for concave and convex lens arrays are complex, time consuming and require expensive.…”

Section: Introductionmentioning

confidence: 99%

Development of a Rapid Manufacturing Process for Concave and Convex Lens Arrays

2019

JESR

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This paper reports a rapid manufacturing process for the production of concave and convex lens arrays on the polymer substrate. In this method, many small steel balls with highly polished surfaces were placed in a rectangular cavity to form a closely packed small steel ball array. Then, a polymer substrate (PMMA sheet) was placed on top of the small steel ball array, and the stack of the PMMA sheet and the small steel ball array was placed in a hot embossing machine. During the hot embossing process operation, a concave lens array pattern is directly fabricated onto a polymer substrate. In addition, the diameter and depth of the concave lens array can be changed and controlled by adjusting the processing conditions of the hot embossing process. Thus, concave lens arrays with different dimension can be fabricated. Next, the polymer substrate with concave lens array pattern can be used as a mold for rapid replication of polymer convex lens array using vacuum-assisted UV molding process. In this way, various concave and convex lens arrays can be rapid fabricated with high throughput and low cost.

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“…Meyerhofer and associates investigated the application of proximity printing in the copy of chrome masks, and shown its potential for replicating 10X step-and-repeat recticles [13]. The fabrication of microlens arrays by exploring the diffraction of light and proximity exposure has been demonstrated by Lin and associates [14], Ping and associates [15], and Yang and associates [16]. Lin and associates fabricated optical waveguides by this same technique [17].…”

Section: Introductionmentioning

confidence: 99%

Diffractive phase-shift lithography photomask operating in proximity printing mode

et al. 2010

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A phase shift proximity printing lithographic mask is designed, manufactured and tested. Its design is based on a Fresnel computergenerated hologram, employing the scalar diffraction theory. The obtained amplitude and phase distributions were mapped into discrete levels. In addition, a coding scheme using sub-cells structure was employed in order to increase the number of discrete levels, thus increasing the degree of freedom in the resulting mask. The mask is fabricated on a fused silica substrate and an amorphous hydrogenated carbon (a:C-H) thin film which act as amplitude modulation agent. The lithographic image is projected onto a resist coated silicon wafer, placed at a distance of 50 µm behind the mask. The results show a improvement of the achieved resolution -linewidth as good as 1.5 µm -what is impossible to obtain with traditional binary masks in proximity printing mode. Such achieved dimensions can be used in the fabrication of MEMS and MOEMS devices. These results are obtained with a UV laser but also with a small arc lamp light source exploring the partial coherence of this source.

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Concave microlens array mold fabrication in photoresist using UV proximity printing

Cited by 20 publications

References 19 publications

Semiellipsoid microlens fabrication method using UV proximity printing

Semiellipsoid microlens fabrication method using UV proximity printing

Development of a Rapid Manufacturing Process for Concave and Convex Lens Arrays

Diffractive phase-shift lithography photomask operating in proximity printing mode

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