This paper will present the direct photo patterning of micro circuits and sensors with a XeCl excimer laser photo ablation system. The working principle and the ablation equipment for photo ablation of conductive thin film on polymer are described. Both large sheets and reel-to-reel webs can be ablated on this excimer laser photo ablation system. The ablation strategies and alignment strategies for the micro circuits and sensors are introduced. The test results show ablation results with high resolution, high throughput, high yield and cost-efficiency. This clearly shows that excimer laser photo ablation of the conductive materials on polymer substrates is a good choice for industrial mass product fabrication of low priced, disposable micro circuit and sensor devices.
This paper describes the design, microfabrication and testing of a pre-aligned array of fiber couplers with integrated out-of-plane microlenses using direct UV lithography of SU-8. The fiber bundle coupler includes a refractive microlens array and two fiberport collimator arrays. With the optical axis of the pixels parallel to the substrate, each pixel of the microlens array can be pre-aligned with the corresponding pixels of the fiberport collimator array as defined by the lithography mask design. This out-of-plane polymer microlens array was pre-aligned with the fiber collimator arrays with no additional adjustment and assembly required. This novel approach helps to dramatically reduce the running cost and improve the alignment quality and coupling efficiency.
This paper describes a novel method to microfabricate out-of-plane convex and concave microlens array with optical axis parallel to the substrate for free-space optics. With wavelength selection and carefully controlled exposure dosage and development in the SU-8 lithography process, the satisfactory surface profiles and uniformity of pixels on the out-of-plane microlens array are obtained. With the optical axis of each pixel parallel with the substrate, these microlens arrays can be we can prealigned with other optical components, such as lens, prism, or mirror, in the mask design. This out-of-plane polymer microlens array can be pre-aligned with other optical components with no additional adjustment and assembly required, and therefore dramatically reduce the running cost and improve the quality and performance of the integrated optical system. Some preliminary results on pre-aligned fiber couplers and fiber bundle couplers fabricated with this out-of-plane microlens array are also presented.
This paper reports a research effort to design, microfabricate, and test a uniquely designed waveguide technology with integrated micro-lenses in vertical orientations. The waveguide and integrated focusing lenses were microfabricated using thick photo-resist such as SU-8 with UV-light lithography. The waveguide can be used in various biological and biomedical systems.
Techniques for fabricating high-aspect-ratio microscale structures (HARMS) are being investigated for wide-ranging applications. Microdevices employing metal-based HARMS are of particular interest for mechanical, electro-mechanical, and chemical applications. In many applications, HARMS with two or several distinct heights are necessary, the fabrication of which necessitates two-level or multi-level mold inserts. In addition, tapered mold inserts would help achieving easy insert-part separation. Here we report a process for fabricating two-level, tapered mold inserts by combining UV-lithography on SU-8 resist, one-step metal electrodeposition, polish and level, and SU-8 resist removal. Without tilt and rotation during the lithography process, tapered SU-8 plating molds are obtained by employing light diffraction during lithography and proper development procedures. The SU-8 resist removal process does not reduce its strength. Efficacy of this approach is demonstrated with a two-level insert prototype suitable for fabricating micro heat exchanger parts by compression micromolding.
We present a novel out-of-plane polymer refractive microlens that can be prealigned with other optical components in a free-space micro-optical bench. This out-of-plane microlens is designed and optimized through simulation, and then successfully microfabricated using a unique UV lithography technology. In this fabrication technology, the desired surface profile is obtained by a controlled SU-8 development after two tilted exposures. The microlens backside focal length, diameter of the focal pad, and the surface curve were measured, analyzed, and compared with the simulation results. The microlenses obtained are perpendicular to the substrate. This out-of-plane prealigned microlens can be used to eliminate the alignment and assembly steps and obtain integrated optical benches. It helps to reduce the running cost, save time, and improve the quality and performance of the integrated optical systems.
To develop an integrated optical bench or free-space optical system, a focusing lens’ optical axis is required to be parallel with the substrate on which the whole system is located. In micro-optical systems, hinged lenses were fabricated in surface technologies and suspended with a mechanical hinge, then driven up to the required vertical position using electrostatic or electromagnetic actuation. In this paper, we report the research work to design, simulate, and
fabricate a new type of microlens using direct lithograph of SU-8 resist. Without any assembly process, this microlens’ optical axis is parallel with the substrate on which the whole optical system is. The lenses obtained this way are perpendicular to the substrate and can be pre-aligned with other micro optical components. The focus of the lens can be controlled with different surface curvature by using different cylindrical beams, expose dosage, and development time. A
numerical simulation is done about the SU-8 development. The optical simulation is also being done with ZEMAX software. At the same time, the optical properties of the cured SU-8 and the optical properties of this cured-SU-8 refractive microlens are also being tested and presented in this symposium.
Using biodegradable polymers for implantable drug delivery purposes has been a very important research area and industry for many years. Polymers, such as PLGA, have been the most attractive one because it does not require removal after the drug has been released. We report a research effort to microfabricate high aspect ratio microstructures of PLGA and its potential applications in implantable drug delivery. The prototypes of packaged cells with dyes have also been made and currently under test for linear release of sample dyes.
An innovative high-resolution maskless lithography system is designed employing a combination of low- and high-numerical-aperture (NA) projection lens systems along with integrated micro-optics, and using Texas Instruments' super video graphic array (SVGA) digital micromirror device (DMD) as the spatial and temporal light modulator. A mercury arc lamp filtered for the G-line (λ = 435.8 nm) is used as the light source. Exposure experiments are performed using data extraction and transfer software, and synchronous stage control algorithms derived from a point array scrolling technique. Each exposure scan produces a field width (W) of approximately 8.47 mm with a field length (longitudinal field) limited only by onboard memory capacity. DMD frame rates of up to 5 kHz (kframes/s), synchronized to the stage motion, are achievable. In this experiment, TSMR-8970XB10 photoresist (PR), diluted to 3.8 cP with PR thinner is prepared. The PR is spin-coated onto a chrome-coated glass substrate to 1.0-μm thickness with 0.1-μm uniformity. A 0.4-μm scan step is used and 27,000 DMD data frames are extracted and transferred to the DMD driver. Results indicate consistent 1.8-μm line space (L/S) resolved across the entire field width of 8.47 mm. Given optimized exposure and development conditions, 1.5-μm L/S is also observed at certain locations. The potential of this maskless lithography system is substantial; its performance is sufficient for applications in microelectromechanical systems (MEMS), photomasking, high-resolution LCD, high-density printed circuit boards (PCBs), etc. Higher productivity is predicted by a custom H-line (λ = 405 nm) lens system designed and used in conjunction with a violet diode laser systems and the development of a real-time driver.
Maskless lithography systems (MLS) presented feature the digital mirror device (DMD) as the pattern generator to replace photomasks. Here 1.5-μm, 10-μm, and 20-μm line/space MLSs are developed. In the MLS, an 848×600 microlens and spatial filter array (MLSFA) was used to focus the light and filter the noise. The MLSFA produces light pads smaller than the 17-μm×17-μm micro mirrors of the SVGA DMD, and filters the noise produced from the DMD, optical lens system, and microlens array. This MLSFA is one of the key components for the Maskless Lithography System, and determines the resolution and quality of maskless lithography. A novel design and fabrication process of a single-package MLSFA for the Maskless Lithography System is introduced. To avoid problems produced by misalignment between a two-piece spatial filter and microlens array, MEMS processes are used to integrate the microlens array with the spatial filter array. In this paper, a self-alignment method used to fabricate exactly matched MLSFA is presented.
For typically small volume production of MEMS, MOEMS, fine feature PCB, high density chip packaging and display panels, especially for lab tests, low cost and the capability to change the original design easily and quickly are very important for customers and researchers. BALL Semiconductor Inc.'s Maskless Lithography Systems (MLS) feature the Digital Mirror Device (DMD) as the pattern generator to replace photo-masks. This can remove masks from UV lithography, and dramatically reduce the running cost and save time for lab tests and small volume production. At Ball Semiconductor Inc, 1.5μm line/space, 10μm line/space, and 20μm line/space Maskless Lithography Systems were developed.
In our MLS, an 848×600 microlens and spatial filter array (MLSFA) was used to focus the light and to filter the noise. In order to produce smaller line-space than 16μm the MLSFA was used to get smaller UV light pad (compared with the SVGA DMD’s micro-mirror: 17μm×17μm) and to filter the noise produced from the DMD, optical lens system, and micro lens array. This MLSFA is one of the key devices for our Maskless Lithography System, and determines the resolution and quality of maskless lithography.
A novel design and fabrication process of a single-package MLSFA for our Maskless Lithography System will be introduced. To avoid problems produced by misalignment between a two-piece spatial filter and microlens array, MEMS processing is used to integrate the microlens array with the spatial filter array. In this paper, the self-alignment method used to fabricate exactly matched MLSFA will be presented.
An innovative High Resolution Maskless Lithography System (Hi-Res MLS) was designed using Texas Instruments’ SVGA DMD, which employs additional micro-optics with a combination of low and high NA projection lens systems. A low power mercury-arc lamp filtered for G-line (λ = 435.8 nm) was used as the light source. Exposure experiments were performed using Ball patented Point Array scrolling or scanning method and proprietary data conversion, extraction and transfer software algorithms. In each scan, the field-width (W) was approximately 8.47 mm with the field-length (longitudinal field) only limited by memory capacity. DMD frame rates of up to 5 kHz (kframe/s) were achievable, which were synchronized to the stage motion. In this experiment, TSMR-8970XB10 photo-resist, diluted to 3.8 cP with PR thinner was employed. The photo-resist was spin-coated on a glass substrate to 1.0-μm thickness with 0.1-μm uniformity. A 0.4-μm step-size was used and 27000 DLP frames were extracted and transferred to the DMD driver. Results indicated consistent 1.8 μm L/S resolved across the entire field-width of 8.47 mm. At certain locales, 1.5-μm L/S was also resolved. The potential of this maskless lithography system is substantial. Even at the current level of performance, the system is sufficient for applications in MEMS, MOEMS, photomasking, high resolution LCD, high density PCB, etc. Higher productivity is predicted by lens system designed for H-line (λ = 405 nm), by using Ball’s violet diode laser systems, and the development of real-time driver.
A novel type of micro power relay has been designed and fabricated using UV-LIGA technology. The relay is based on electrostatic actuation and SU-8 was used as a functional material. The unique character of this novel power relay is that other than a SU-8 structure used both as an electrical insulator and a mechanical connector, all other components are made of metal or alloys. Because UV-LIGA technology has the advantages of broad material selection and the capability of making high aspect ratio microstructures, the technology is best suited for fabricating microelectromechanical power relays. A multi-step, multi-layer UV-LIGA process has been successfully developed and a prototype relay has been successfully fabricated.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.