The printed circuit board (PCB) industry is vital to manufacturers of computing components, automotive parts, cellular phones, flat-screen television displays and other devices considered essential to our modern lifestyles.

In addition to a large number of PCB enterprises in Taiwan, many PCB operations are located in Jiangsu, Zhejiang and Guangdong provinces.

Among them are leading PCB makers earning hundreds of millions of dollars in annual revenues and employing thousands of workers.

They also spend huge sums on environmental protection, including the disposal of manufacturing wastes from production processes and everyday operations.

The major pollution source of PCB industries is the copper content in the spent etchant and wastewater streams.

Traditionally, liquid resin is used to chelate spent etchant, forming copper ions and converting them into a copper sulfate solution for industrial applications.

Although this process can recover most of the copper from PCB waste streams, a considerable amount of the metal is unrecoverable. This metal is discharged into the environment, which can cause severe water pollution problems.

For any major plant, the daily amount of wastewater, along with untreated sludge, can total thousands of tons. This wastewater and sludge contains copper and also lead, tin and other metals used in soldering processes.

Stricter environmental protections adopted in recent years have forced PCB manufacturers to seek new technologies to promote better, yet cost-efficient waste recycling methods.Shortly after the State Council announced its 4 trillion yuan stimulus package to boost the domestic economy, attention turned to reviving industrial sectors battered by the ongoing global economic crisis.

During a series of meetings by the State Council in January and February this year, an “industrial restructuring” policy was adopted that focused on “10 key sectors.” The PCB industry is among those key sectors.

The government asked that PCB manufacturers focus on two elements: cleaner production (CP) and a circular economy (CE) to make this industry environmentally clear and economically stronger.

A semi-annual PCB technical conference in May at Suzhou, Jiangsu province, answered this CP/CE challenge with green technology sessions and economic discussions.

Hundreds of Chinese companies were represented – all eager to learn innovative technologies and international market trends.

Papers were presented on energy-saving measures, emissions reductions and also proposed CP/CE practices.

Seven universities in Taiwan established an incubator to study “best practice” CP/CE applications at the Center for Innovation and Incubation at Chung Yuan University.

The center has invited the participation of industry representatives, academic institutions and the government.

A persistent challenge is the incomplete recovery of copper from plant discharges, wastewater and sludge.

A recovery procedure recently developed by Taiwan-based Trinity Resource Technology Inc has employed a CP/CE solution.

The procedure involves separating copper compounds from wastewater in a way that recovers most of the copper, resulting in near-zero discharge.

Through a chemical treatment method operated outside the plant premises, the recovered copper compound is purified to form copper oxide, which can be recycled and used in the PCB electrolysis process.

Trinity is working with Chung Yuan University to build a pilot plant employing this new procedure.

This new approach is an example of the innovation that is being sought by the PCB industry to produce useful, profitable and environmentally sound products.

The author is a scientist and advisor to Trinity Resource Technology Inc of Taiwan
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(China Daily)