Environmental Issues

CONFERENCE FOCUSES ATTENTION ON RENOCELL

Peter Young, Project Consultant for PAL-ED (PAL Environment Department) presented the benefits of RenoCell chemistry-free integrated Electrowinning technology for air and water metal contamination control in a new PTH production unit at a recent Singaporebased conference.

“My presentation described how a new high capacity automatic PTH Desmear production process line, used for the cleaning and metallisation of holes and blind vias in printed circuit boards, was designed and built with integrated water saving and waste contaminant control,” explains Peter Young. “This was for waste water from rinses and fume exhaust, so that the continuous waste water output contained less than 2ppm Copper and the waste gases complied with the stipulations of the U.K. Environment agency.”

The plant design was required to remove 100% of the EDTA arising from the solution purge or blow down from the Electroless Copper plating solution, and it was preferred that chemical reagents were used to a minimum. This design requisite would be in compliance with the CE Directive on Integrated Pollution Prevention and Control, the so-called IPPC programme, that requires all manufacturers with more than 30,000 litres of installed tankage to be controlling pollution at source by 2003 for existing facilities, and immediately for those installing new machines.

The design put forward and recently constructed, used high efficiency RenoCell electrowinning cells attached to control or dragout rinses after the major Copper containing processes, which eliminated Copper in the following flowing rinses to less than 1ppm and reduced the volume of following rinse water by 60% as compared to conventional rinsing.

The fumes were captured using a vertical packed scrubbing tower, which transferred the contaminants into water, which was combined with the Electroless Copper blow down, and processed in a secondary Electrowinning batch treatment system, which also used RenoCells to plate out the Copper to less than 2ppm., destroyed the EDTA by oxidation at the anode (60%) and completed the destruction using ultraviolet light to generate ozone and free Hydroxyl radicals from the oxygen generated at the DSA anode (40%). These techniques use electrical power only so the need to avoid chemical reagents was completely satisfied. In that the Copper waste contaminants are converted into Copper metal fixed to the renewable carbon matrix of the RenoCell cathode cartridge, hazardous sludge is totally avoided and the Copper can be sold to a smelter as scrap Copper instead of being a cost of operation.

The full paper is available from Peter Young via PAL (UK) Ltd or via the PAL-ED office at PAL headquarters.

Above: RenoCell System with controls, pump and Rectifier

MORE RENOCELL INSTALLATIONS

Labtech saves on waste treatment capability investment. The automatic Nickel Gold line supplied by PAL to Labtech in the UK has minimal waste impact but the Copper arising from the pre-treatment micro etch was considered to be a significant contribution to the total Copper output from the factory which is under increasing pressure to be reduced to comply with newly imposed environmental standards.

The inclusion of a control, or dragout, rinse after the dragout, allowed the installation of an M500 RenoCell, which removes the dragged in Copper to less than 1.0 ppm, and means that the facility will not contribute any Copper to the waste discharge. The compact installation within the process line side equipment meant that no additional space was required and no chemical dosing facilities were necessary. This minimises the health and safety issues as well as operator attendance. The recovery cartridge is cleaned weekly at the same time as plant maintenance, giving easy and minimal servicing labour requirements.

And in India too Micropack, one of India’s pioneers in the PCB market – and part of the Sanmar group of companies, produce nearly 60,000 sq. m of high quality boards each year for the defence and telecom sectors. Recently they added a second transporter and two Copper tanks to increase their production capacity. That’s not all they have added. They have installed a RenoCell, which is currently undergoing trials.

ENVIRONMENTAL PROTECTION ON NEW PROJECTS IN CHINA

PAL has, as reported in many past issues of PAL News, worked on the construction of greenfield site PCB fabrication facilities and has detailed the construction of water supply treatments, waste water treatments and air pollution abatement equipment.

“One aspect that we have been heavily involved in over the last few years is the work involved in obtaining permits to construct and operate the facilities, which require onerous and significant submissions to satisfy the Environment Protection Bureaus in regard to issuing the permits,” explains Peter Young, Project Consultant for PAL-ED (PAL Environment Department).

“The submissions are required to detail a model of the waste outputs and the measures to abate any pollution nuisance to achieve compliance with the applicable standards for discharge. These permits are modelled on the work that the building’s structural engineer would make to verify the suitability of the design, but are certainly unfamiliar territory for facility engineers.

“Whilst operating data from existing facilities elsewhere will give a potential starting basis the likelihood that newer and more environmentally friendly production machines will be employed does mean that the waste profile will need to be modified and justified. The treatment technology has to be proved with application of rigorous scientific data and the less usual control parameters of Chemical Oxygen demand require detail investigation and modelling. Having prepared all this data it is necessary to submit it under the authentication of a recognised Professional Engineering Bureau.

“This can be the client’s architect and engineer if they possess the accreditation. Many do not. As a service to all its environmental customers PAL has prepared many of these files and by representation can answer the questions raised. The approval often includes demonstration of the concepts and technologies employed, which can be achieved by visiting reference installations. If the client’s engineer is unqualified to make the submissions PAL has partners in the major Provinces of China. PAL’s registration as a recognised Company in Southern, East Central (Shanghai and Jiangsu province) and Northern China covers the locations for new facility build and this includes local after sales service. This experience and local knowledge avoids project delays and unforeseen costs.

Below: Waste Water treatment plant Constructed in Suzhou, PRC.