The LIGA Process: A Fabrication Process for High-Aspect-Ratio Microstructures in Polymers, Metals, and Ceramics

Bio-MEMS ◽  
2006 ◽  
pp. 53-102
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Wenzheng He ◽  
Xiongying Ye ◽  
Tianhong Cui

AbstractTraditional lithography plays a significant role in the fabrication of micro- and nanostructures. Nevertheless, the fabrication process still suffers from the limitations of manufacturing devices with a high aspect ratio or three-dimensional structure. Recent findings have revealed that shrink polymers attain a certain potential in micro- and nanostructure manufacturing. This technique, denoted as heat-induced shrink lithography, exhibits inherent merits, including an improved fabrication resolution by shrinking, controllable shrinkage behavior, and surface wrinkles, and an efficient fabrication process. These merits unfold new avenues, compensating for the shortcomings of traditional technologies. Manufacturing using shrink polymers is investigated in regard to its mechanism and applications. This review classifies typical applications of shrink polymers in micro- and nanostructures into the size-contraction feature and surface wrinkles. Additionally, corresponding shrinkage mechanisms and models for shrinkage, and wrinkle parameter control are examined. Regarding the size-contraction feature, this paper summarizes the progress on high-aspect-ratio devices, microchannels, self-folding structures, optical antenna arrays, and nanowires. Regarding surface wrinkles, this paper evaluates the development of wearable sensors, electrochemical sensors, energy-conversion technology, cell-alignment structures, and antibacterial surfaces. Finally, the limitations and prospects of shrink lithography are analyzed.


Author(s):  
Daiji Noda ◽  
Masaru Setomoto ◽  
Tadashi Hattori

Recently, the demand of micro-fabrications such as micro-sensors, microcoils, micro-actuators etc is increasing. Actuators account for a large percentage and volume and weight of a product compared with other parts. Therefore, the progress in downsizing of actuators was required. In order to resolve these problems, the key technology to realizing micro-devices is micro-fabrication process. Particularly, it is essential to the technologies for processing high aspect ratio structures in the production of micro-parts. We have proposed a three-dimensional fabrication process using X-ray lithography technique, and fabricated spiral microcoils having coil lines of narrow pitch and high aspect ratio structures. We have fabricated spiral microcoils at a pitch of 60 μm, and aspect ratio of about 5 using X-ray lithography and narrow metallization techniques on acrylic pipe surface. In addition, we also estimated the suction force of electromagnetic actuators using these microcoils. Measurement results were relatively in good agreement with theoretical values using high aspect ratio microcoils. It is very expected that the high performance microcoils could be manufactured in spite of miniature size.


2000 ◽  
Author(s):  
Jordan Neysmith ◽  
Daniel F. Baldwin

Abstract This paper outlines the motivation behind, and fabrication process for, a novel through-wafer electrical interconnect structure. The interconnect was designed in order to test the feasibility of routing electrical signals through full thickness silicon wafers. The completed interconnect is compatible with solder-based direct-chip-attach (DCA) processing and CMOS circuitry. The core of the through-wafer electrical interconnect structure consists of a high-aspect-ratio via which is subsequently insulated and metallized. On the wafer backside, an under bump metallurgy (UBM) is added around the via opening and a solder bump is formed to complete the interconnect.


Sign in / Sign up

Export Citation Format

Share Document