Columbia Technology Ventures

Enhancement of laser oxide removal processes for plating (LORP) simplifies one-step plating of oxide-coated materials

Laser oxide removal for plating (LORP) is a plating preparation system that uses laser irradiation to remove the native oxide film from the substrate immersed in an electrolyte solution. While LORP reduces the pre-processing required to plate metals and allows for simultaneous plating and oxide removal, it also suffers from drawbacks such as high cost and time consumption as well as the use of environmentally harmful chemicals. This technology presents several improvements over previously developed LORP techniques that serve to reduce cost and minimize optical attenuation, thus increasing the efficiency of the system. These improvements include the use of a thin electrolyte layer and the removal of the electrolytic cell window through which the laser beam passes. The improved LORP system functions by wetting a porous material in contact with the substrate to cause immersion plating. The substrate is then passed into a second tank for plate-up via electroplating.

Use of a thin electrolyte layer reduces waste, while removal of the cell window and use of a long focal length lens increases optical efficiency

An electrolyte layer that is only several microns thick serves to reduce optical attenuation and minimize waste of electrolyte. In previous LORP configurations, a long focal length lens was required to prevent damage to the electrolytic cell window through which the laser beam passed. This increased the travel distance of the laser resulting in substantial optical attenuation. In the improved system, the removal of the cell window turns the long focal length lens into an advantage. The distance between the focal lens and laser can be made arbitrarily large, preventing the lens from being splashed by electrolyte. These improvements enhance the LORP process by reducing laser damage to the electrolytes, decreasing electrolyte waste, and increasing the efficiency of the laser for oxide removal. A number of oxide metals will be tested at 532 and 266 nm using Q-tips to wet the sample just prior to laser impingement.

Lead Inventor:

Robert J. von Gutfeld, Ph.D.

Applications:

  • Plating for RF applications
  • Plating to enable soldering and bonding
  • Corrosion inhibition for the manufacturing of computers, mobile phones, electronic devices
  • Coating for wear, chemical resistance, and low friction interfaces for automotive, aerospace and petrochemical fields
  • Coating of microelectrode arrays, pin grid arrays, semiconductor wafers, and medical devices such as catheters, pacemaker leads, titanium coated rods and screws
  • Maskless pattern definition
  • Surface modification of steel and other metals for corrosion resistance
  • MEMS multilayer fabrication
  • Gold/silver/platinum plating for low cost jewelry and art
  • Activated surfaces for chemical reactions, such as carbon nanotube growth
  • Thermal interfaces using copper thin films for enhanced heat transfer between metal cooling components for semiconductor chips

Advantages:

  • Eliminates the need for time-consuming and environmentally hazardous pre-processing steps
  • Reduces electrolyte waste
  • Improves adhesion of plated layer
  • Minimizes optical attenuation to improve laser efficiency
  • Maximizes process design flexibility because processes can take place in or out of the plating electrolyte
  • May be used for reel-to-reel plating

Patent Information:

Patent Pending (US20110104396)

Tech Ventures Reference: IR M10-023

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