Dry Film Photoresist-Based Microfabrication: A New Method to Fabricate Millimeter-Wave Waveguide Components

Abstract

This paper presents a novel fabrication method based on dry film photoresists to realize waveguides and waveguide-based passive components operating at the millimeter-wave frequency (30–300 GHz). We demonstrate that the proposed fabrication method has a high potential as an alternative to other microfabrication technologies, such as silicon-based and SU8-based micromachining for realizing millimeter-wave waveguide components. Along with the nearly identical transfer of geometrical structures, the dry film photoresist offers other advantages such as fewer processing steps, lower production cost, and shorter prototyping time over the conventional micromachining technologies. To demonstrate the feasibility of the fabrication process, we use SUEX dry film to fabricate a ridge gap waveguide resonator. The resonator is designed to exhibit two resonances at 234.6 and 284 GHz. The measured attenuation at 234 GHz is 0.032 dB/mm and at 283 GHz is 0.033 dB/mm for the fabricated prototype. A comparative study among different existing technologies indicates that the reported method can give a better unloaded Q-value than other conventional processes. The measured unloaded Q-values are in good agreement with the simulated unloaded Q-values. The signal attenuation indicates that SUEX dry film photoresists can be used to fabricate passive devices operating at millimeter-wave frequencies. Moreover, this new fabrication method can offer fast and low-cost prototyping.

Micromachined Wideband Ridge Gap Waveguide Power Divider at 220–325 GHz

“…During the optimization of all the sensitive parameters, ± 10 µm pin height tolerance has been considered also. From our previous experiments on SUEX dry film photoresist the achieved fabrication tolerance was ± 2 µm [14]. Thus, the designed T-junction power divider is expected to perform well after manufacturing.…”

“…Dry film photoresist on the other hand can overcome all abovementioned fabrication issues. Recently SUEX dry film photoresist has been used to fabricate waveguide components operating above 200 GHz [14], verifying that dry film photoresist not only delivers superior geometrical features and fabrication tolerances, but also reduces the processing time and the production cost.…”

Introduction of Photopolymerization Technology and Application

“…Due to its unique advantages of uniform thickness, controllable, stability, high reliability, easy operation, low energy of exposure and high resolution, DFRs has developed rapidly, and has been widely utilized in PCB manufacturing process. [105][106][107][108] As displayed in Figure 28, the polyester (PET) film, photoresist layer and polyethylene (PE) film from bottom to top together constitute a complete DFRs. [109] The PET film plays the role of bearing photoresist layer, and PE film is used to avoid the deterioration caused by the contact between photoresist layer and dusts or oxygen, in addition, prevents adhesion between multilayer film.…”

Cost‐effective fast prototyping using a dry film photoresist for micromixers towards point‐of‐care devices

“…[15] S. Farjana et al presented a novel fabrication method based on dry film photoresists to realize waveguides and waveguide-based passive components operating at the millimeter-wave frequency (30-300 GHz). [16] M. Nilsen et al reported the use of commercially available dry film photoresists (5 μm thick) onto prepatterned silicon substrates that contain atomic force microscopy compatible probe bodies. [17] To elucidate the effectiveness of the fabrication method based on dry film photoresist further, here we use a commercial Riston FM800 photopolymer film (DuPont de Nemours, Inc., USA) to fabricate the high-performance micromixer.…”

“…presented a novel fabrication method based on dry film photoresists to realize waveguides and waveguide‐based passive components operating at the millimeter‐wave frequency (30‐300 GHz). [ 16 ] M. Nilsen et al . reported the use of commercially available dry film photoresists (5 μm thick) onto prepatterned silicon substrates that contain atomic force microscopy compatible probe bodies.…”