Location History:
- Fullerton, CA (US) (1994 - 1996)
- Brea, CA (US) (1998)
Company Filing History:
5 out of 9 
2 out of 2 Years Active: 1994-1998
Title: Innovations by Rajwant Singh
Introduction
Rajwant Singh is a notable inventor based in Fullerton, CA (US). He has made significant contributions to the field of chemical development, particularly in the printed circuit industry. With a total of 7 patents to his name, Singh's work focuses on enhancing the efficiency and sustainability of chemical processes.
Latest Patents
One of his latest inventions is a method for increasing the effective process life and chemical efficiency of aqueous-based developer solutions used in photoresist development. This invention allows for the regeneration of byproducts during the process to active carbonate, using controlled additions of alkaline hydroxide instead of conventional carbonate solutions. The pH and development speed can be automatically controlled at any desired constant value. This innovation simplifies the automation of printed circuit photoresist development, reduces chemical costs, and increases chemical usage efficiency, thereby minimizing industrial waste volume.
Another significant patent is a process for controlling the recycle of ammoniacal copper etchant. This process utilizes metallic aluminum to remove copper without adding undesirable byproducts. By controlling the temperature and mixture rate, the rapid reaction can be managed effectively. The copper concentration is monitored by colorimetry while maintaining the pH above 8. The separated metallic copper and aluminum hydroxide sludge can be easily filtered from the etchant, making the purified etchant suitable for chemical adjustment and reuse.
Career Highlights
Rajwant Singh has worked with several companies, including Applied Electroless Concepts Inc. and Applied Chemical Technologies, Inc. His experience in these organizations has contributed to his expertise in chemical processes and innovations.
Collaborations
Some of his notable coworkers include Gerald A. Krulik and Nenad V. Mandich. Their collaboration has likely fostered an environment of innovation and shared knowledge in their respective fields.
Conclusion
Rajwant Singh's contributions to the field of chemical development through his patents demonstrate his commitment to innovation and sustainability. His work not only enhances efficiency but also addresses environmental concerns in the industry.