The field of laser micromachining is highly diverse. There are many different types of lasers available in the market.
Due to their differences in irradiating wavelength, output power and pulse characteristic they can be selected for
different applications depending on material and feature size [1]. The main issues by using these lasers are heat
damages, contamination and low ablation rates. This report examines on the application of the Laser MicroJet(R) (LMJ), a
unique combination of a laser beam with a hair-thin water jet as a universal tool for micro-machining of MEMS
substrates, as well as ferrous and non-ferrous materials. The materials include gallium arsenide (GaAs) & silicon wafers,
steel, tantalum and alumina ceramic. A Nd:YAG laser operating at 1064 nm (infra red) and frequency doubled 532 nm
(green) were employed for the micro-machining of these materials.
High-brightness LEDs are compound semiconductor devices and distinguish themselves from conventional LEDs by
their exceptional luminosity. Today they are increasingly used as light sources, replacing conventional incandescent and
fluorescent lamp technologies. HB LEDs are difficult to manufacture, as they must be grown by sophisticated epitaxial
growth techniques such as MOCVD. They are packaged like power semiconductors, using surface mount technology and
thermal pads.
After having been successfully applied to GaN scribing for side-emitting LEDs, the Laser MicroJet(R) is used today for
cutting heat sinks of HB white LEDs. Due to the high-emitted light power, the generated heat must be dissipated through
a heat sink. Materials typically employed are metals with high heat conductivity, notably CuW and molybdenum.
Applying the Laser MicroJet(R) the achieved cutting quality in these metals is outstanding - smooth edges, no
contamination, no burrs, no heat damage, no warping - all this at high speed.
Inside inkjet-printer heads, a silicon chip is used as a barrier between the orifice plate, which contains hundreds of
nozzles, and the ink reservoir. The silicon chips used to create the barriers have to be drilled. The conventional
manufacturing technique (sandblasting) does not anymore provide satisfactory results for the new generation of printers.
The water-jet-guided laser, a hybrid technology which uses a water jet to guide a laser beam, has recently been adapted
to this application, showing very promising results combining high processing speed and quality.
Microfluidics has become one of the most intense research fields in MEMS technology. In this paper, the use of a 1064nm Q-switched solid state laser to fabricate micro-pump cavities in copper is presented. The focusing technique is employed fore directly structuring the micro-pumps and mixers. In this case, a laser beam with a focal spot of 50 micrometers is canned over the surface and the substrate material is ablated track by track and layer by layer. Machining results such as surface finishing and dimensional resolution are discussed. The dependence of the ablation depth, ablation rate and surface roughness on the process parameters and on the scan overlap are investigated. The laser micromachined structures are free of cracks and without any deposition of debris on the surface. The assembly and first characterization results of the pumps are reviewed. The capability as well as the potential of laser micromachining are also discussed.
Product miniaturization and component intricacies require advanced processing technologies to satisfy functionality and quality requirements. Various micro-machining technologies have been under extensive development so as to be able to fill this niche. In particular, the development of MEMS devices utilizes machining methods that include silicon fabrication and LIGA technologies. Lasers present an alternative or supplementary tool for micro-fabrication. Present advances in laser system design are bringing about great improvements in beam quality, increase in high peak power, increase in high pulse energy, and shorten pulse width. This enables direct machining of a wide variety of materials with feature sizes down to the order of micrometers. This paper presents some of the recent developments in utilizing laser to micro-machine or micro-fabricate micro- features on devices. Many of these processes are being used in production, or are expected to be commercially feasible.
Conference Committee Involvement (1)
Laser-Based Micro- and Nano-Packaging and Assembly (LBMP-IV)
22 January 2007 | San Jose, California, United States
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.