By: Dr. Lim Gnian Cher
Laser is a potential tool for machining structural profiles on hard and brittle materials such as ceramics and carbides that traditional tools and methods find them near impossible to do. EDM (electro-discharge machining) may be used for substrates that are conductive, such as tungsten carbide. However, drilling small holes or machining channels and other features that are less than 100 um in dimensions cannot be achieved even with EDM.
By: Khai Pham Xuan, Kazuya Saginawa, Rie Tanabe, Yoshiro Ito
Department of Mechanical Engineering, Nagaoka University of Technology
Recently, high precision molds for small products are being highly required in many industrial applications, especially in information communication technology. Mold materials with high hardness, such like cemented tungsten carbide (WC-Co), are difficult to machine by classical chip-removal techniques and the electrical discharge machining (EDM) is mainly used technology in microfabrication of hard materials. Even though the accuracy of EDM is fairly high K.H. Ho and S.T. Newmann, State of the art electrical discharge machining (EDM), it has several drawbacks such as slow machining rate and the additional time and cost needed for polishing and finishing processes. Recently, laser machining becomes an effective technique for machining of hard materials. Many experimental results show that short pulse laser machining allows removal of very small amount of material with little heat affected zone compared with nanosecond or longer pulse lasers.
By: Kun Li, William O’Neill, Jack Gabzdyl
Institute for Manufacturing, University of Cambridge
SPI Lasers
The micro-machining of silicon components for use in the MEMS fabrication and microelectronics industry is well-established, and the demand for semiconductors started to recover after the 2008 downturn. Laser micro-drilled interconnect via holes is an application that has been applied in high volume manufacturing since 1995. In 2006, the laser held 70% of the microvia market because of its broad processing capabilities with a wide range of materials. Meanwhile the photovoltaic (PV) industry has experienced enormous growth over last few years, and it forecasts to grow to $100 billion between 2008 and 2013 (Lux Research, NY). As the most important material, c-Silicon has 77% of market share of world production of solar cells NanoMarket web (2009). Additionally, many novel high efficiency solar cell concepts (Emitter Wrap Through & Metal Wrap Through) are only feasible with laser technology, since it satisfies the requirement of drilling a few thousand holes (50-100µm in diameter) per second in c-Si.
