What are the three steps in the LIGA process?

What are the three steps in the LIGA process?

Overview. The LIGA consists of three main processing steps; lithography, electroplating and molding.

What’s UV LIGA process?

UV- LIGA process uses a polymer resist sensitive to UV-rays, which can be patterned using lithography techniques. After development of the resist, 3-dimensional structure with trenches is left behind on a conductive substrate into which the metallic struc- tures are electroplated.

What are the advantages of LIGA process?

The major advantages of the LIGA process are the high aspect ratios made possible and therefore the larger heights of the pieces, very sharp vertical sidewalls as well as the possibility to produce three-dimensional structures by using a sacrificial layer as described above.

What are the significant advantages and disadvantages of the LIGA process?

Advantages: small surface roughness, resulting nickel tool has a good surface chemistry for most polymers. Drawbacks: slow growth rate of nickel in the electroplating process (10-100µm/h), high stress levels in thick nickel layers, radial dependency of the growth rate (unwanted difference of structures height).

What is bulk and surface micromachining?

Bulk micromachining is a process used to produce micromachinery or microelectromechanical systems (MEMS). Whereas surface micromachining creates structures on top of a substrate, bulk micromachining produces structures inside a substrate.

What are the different types of lithography?

Overview. There are different types of lithographic methods, depending on the radiation used for exposure: optical lithography (photolithography), electron beam lithography, x-ray lithography and ion beam lithography.

Why is electroplating necessary in a LIGA process?

Primarily the LIGA-process provides high aspect ratio micro structures in polymers like e.g. PMMA (better known as acrylic glass). Via electroplating these structures can be replicated in metals like gold, nickel, magnetic nickel-iron alloys or copper. Even replications in ceramics are possible.

Where is micromachining used?

Surface micromachining is used to pattern the backside as well as to create a metal electronic sensing circuit on the frontside of the wafer. Below is the process used to fabricate this MEMS pressure sensor. A thin film of silicon nitride is deposited onto both sides (frontside / backside) of the wafer.

What are the techniques of micromachining?

Therefore the most important techniques will be presented, focusing on photolithography (bulk & surface machining), LIGA, laser, micro-EDM, micro-USM and microme-chanical machining (microcutting and micromilling).

What is lithography process?

Lithography is a printing process that uses a flat stone or metal plate on which the image areas are worked using a greasy substance so that the ink will adhere to them by, while the non-image areas are made ink-repellent.

What is the difference between etching and lithograph?

Etching is frequently mistaken for lithograph, which requires the craftsman to cut into the material utilizing a sharp instrument. Etching incorporates the demonstration of printing. When a metal plate has been carved, the wax ground is evacuated and its surface is shrouded in ink.

What is the core process in Liga?

The core process in LIGA is deep X – ray lithography at a synchrotron radiation source. X – ray lithography ( XRL ) as such was proposed in the 1970s for semicon- ductor patterning and fi rst demonstrated by IBM using synchrotron radiation at the German National Laboratory DESY in 1975 [ 5 ].

What is Liga technology?

The fi rst publication on LIGA technology – LIGA is a German acronym for litho- graphy, electroplating and polymer replication – appeared in 1982, more than 25 years ago [ 1 ]. Since then, the LIGA technique has been successfully used in many research projects.

Where can I find references for Liga?

A compilation of many relevant references for LIGA may be found in review papers, for example, Refs [ 2, 3 ]; the LIGA basics and technical limits are well documented and explained in textbooks, such as Ref. [ 4 ]. The core process in LIGA is deep X – ray lithography at a synchrotron radiation source.

What is STEP-5 Liga micromaching process?

Step-5 After photoresist removal, metal structure formed may be used as mold. Sacrificial techniques are combined with the basic LIGA process to create partially freed, flexure-suspended structure or completely freed devices. LIGA Micromaching Process 7.