The goal of electroplating (Electro Chemical Deposition, ECD) is the deposition of metal films and structures to fabricate functional films and microstructures with high thickness or high aspect ratios.
- Fabrication of microstructures out of Ni, Cu
- Substrate size: Ø 100 mm, Ø 150 mm, Ø 200 mm (depending on chosen equipment)
- Substrate thickness: 2 mm
- Max. film thickness: 2 mm
- Various electrolytes (Cu, Ni, Sn, Ag, Au)
- Design qualification of processes and tools
- Implementation and commissioning of processes at customers' own sites
- Hands-on electroplating training
- Fabrication of molds and dies (UV-LIGA)
- Metallic microsystems components (UV-LIGA)
- Under bump metallization (Cu, Ni, Au)
Electroplating involves the deposition of metals using an aqueous electrolyte solution with the use of an external applied current.
It is important to distinguish between decorative and functional electroplating. Decorative coatings include chrome plating of steel tubes, gold plating of jewellery, or chrome plating of plastics (e.g. faucets). Functional electroplating is especially useful for corrosion prevention (e.g. zinc plating of screws), erosion prevention (e.g. hard chrome plating of rollers), and controlled catalyzer deposition (e.g. nickel and platinum containing catalyzers for the chemical industry). In microsystems technology, electroplating is most commonly used for packaging technologies including bonding layers and for UV-LIGA applications.
In UV-LIGA processes, a negative form of the desired structure is patterned on the substrate through photolithography using a suitable photoresist. Subsequently, the openings on the surface are filled with the selected metal through the electroplating process. Nickel and copper are the most commonly used metals in this process.
A special application of the UV-LIGA process is the fabrication of molds for injection molding and hot embossing in the micro scale. By allowing the resist pattern to overgrow, Shims can be fabricated. These can then be further processed to result in mold and die structures.
In packaging applications, the electrical properties (electrical conductivity), thermal properties (thermal conductivity, maximum operating temperature, diffusion properties) and the compatibility and processibility with other utilized materials (ability to solder, corrosion, ...) are of interest. Often, combinations of thin films (e.g. adhesion layers, seed layers) and electroplated layers, or layers strengthened by electroplating are used. The main challenge with ECD is to realize the interface between the microtechnological components and the outside world.