Soldering mask laser removal from printed circuit boards aiming copper recycling

Journal Article · Sun Oct 15 04:00:00 EDT 2017 · Waste Management

DOI:https://doi.org/10.1016/J.WASMAN.2017.07.019· OSTI ID:22742143

De Pretto, Lucas Ramos; Zezell, Denise Maria

Highlights: • Use of laser as a tool for recycling of electronic waste is proposed. • Laser stripping removes varnishes from circuit boards exposing the copper underneath allowing electrochemical copper recover. •Good removal is achieved with nanosecond pulsed irradiation at 1064 nm. • Waste generated by the process is mainly solid, macroscopic and easy to handle. - Abstract: Management of waste of electric and electronic equipment (WEEE) is a key issue for modern societies; furthermore, it contains valuable materials that can be recycled, especially in printed circuit boards (PCB), which have approximately one-third of their weight in copper. In this study we demonstrated the use of laser to strip the covering soldering mask on PCB’s, thus exposing the copper underneath so that extraction techniques may take place. Using a Q-Switched Nd:YAG laser operating at 1064 nm and 532 nm we tested the procedure under different energy conditions. The laser stripping of the soldering mask was achieved with satisfactory results by irradiation with 225 mJ at 1064 nm. However, when using similar parameters at 532 nm the process of the coating ejection was not promoted properly, leading to a faulty detachment. Infrared laser PCB stripping presents itself to be technically viable and environmental friendly, since it uses no chemicals inputs, offering one more option to WEEE treatment and recycling.

• OSTI ID: 22742143
• Journal Information: Waste Management, Journal Name: Waste Management Vol. 68; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
COPPER
ELECTRONIC EQUIPMENT
ELECTRONIC WASTES
NEODYMIUM LASERS
PRINTED CIRCUITS
PULSED IRRADIATION
RECYCLING
REMOVAL
RESPIRATORS
SOLDERING
TESTING
WASTE MANAGEMENT