Water Reduction and Reclamation in PCB Manufacturing

It’s no secret that PCB manufacturing uses copious amounts of water—as much as 264 billion gallons per year. Until a recent shift in trend, sustainability initiatives have been mainly focused on decreasing carbon emissions and energy consumption. However, the industry is now turning toward water reduction and reclamation to preserve natural resources and contribute toward a more balanced (and health-safe) planet. And it couldn’t be soon enough.

Research conducted by the US Forest Service found that nearly half of the 204 freshwater basins in the US may not be able to meet monthly water demand by 2071, citing population growth and climate change as reasons for the shortage.

Although large manufacturers have been managing their material waste and wastewater, they are now setting and committing to aggressive goals to drive more impactful change.

Amkor Technology, for one, has set a firm target,.“At present, our key sustainability goals are to reduce GHG (greenhouse gas) emissions, water usage, and waste generated by 20% by 2030, from the baseline average of 2018 to 2020. We continue to monitor our progress, and we are on track to meet our goals,” stated HyeJu Lee, vice president of compliance at Amkor Technology.

“We have implemented a thorough water management program at our manufacturing facilities worldwide,” said Amkor’s Lee. “As part of this effort, we continue to operate reverse osmosis systems at our facilities, allowing us to purify the process water and reuse the water in our manufacturing process. Reverse osmosis systems are combined with electro-deionization (EDI) systems, and it uses less than 95% of the chemical products used in the conventional ion exchange processes. This helps to reduce freshwater usage, improve water efficiency, and protect the environment. We continue to reduce our water usage and contribute to the preservation of water resources. Our total water withdrawal intensity decreased by 12% from 2021 to 2022.”

As Amkor’s example shows, to meet targets, organizations must engrain sustainability into operating models and invest in new, more earth-friendly technologies.

TTM: A Case Study in Integrating Sustainable Water Management

At the core of TTM Technologies’ (a large printed circuit board manufacturer) environmental management is its Environmental Statement and Environmental Policy, which encourages innovation, education, training, creativity, the use of proven technology, and the implementation of sound practices and procedures to continually minimize the company’s impact on the environme.

TTM has taken a measured, systematic approach to sustainable water management, weaving its water footprint reduction efforts into its existing operational structures, including key performance indicators (KPIs), capital plans, and sustainability goals and measuring environmental performance as it does production performance and providing the resources necessary to ensure the reduced use of natural resources in the manufacturing of its PCBs, electrical assemblies, parts, and components.

TTM has segregated its water use reduction initiatives into the following categories: wastewater treatment and system upgrades, water segregation, water use reduction, and stormwater: no exposure certified facilities.

As reported by PCB007 Magazine, in the area of wastewater treatment and system upgrades, TTM gradually replaced precipitant-based wastewater treatment (WWT) systems that relied on chemical treatment agents to remove metal contaminants and produced reclaimable material that required excessive energy and/ or handling to reclaim metal, adding costs and resulting in poor returns in favor of selective ion exchange.

“TTM has undertaken the elimination of chemical precipitation WWT systems (clarifiers, batch precipitation, and micro-filtration) in favor of selective ion exchange. The ion exchange systems are very similar to the deionized water systems that most manufacturing processes employ to provide product water of the correct technical specification. Most of these ion exchange WWT systems are built in-house by TTM, utilizing off-of-the-shelf industrial equipment and water treatment technologies. This approach provides a smaller, more sustainable footprint for the same treatment needs. Over time, TTM has found that this means of treatment is scalable and can be altered to reflect or respond to increased manufacturing capacity utilizing the same basic WWT infrastructure. Selection of the correct ion exchange resin media is key to developing a robust and repeatable treatment process.”

The ASE Group: A Global Company with a Regional Approach

Water scarcity is a growing global issue.

Semiconductor manufacturing consumes a vast amount of water; a single fab can use tens of millions of gallons per day, putting a massive strain on a region’s water resources. As fabs are often located in water-constrained regions, multinationals must prioritize their efforts and take a strategic, regionally sensitive approach.

“As part of our ESG strategy, we continue to make strides in achieving water savings,” said Lam Research’s Covell. “In 2022, we exceeded our goal to achieve 17 million gallons of water savings in water-stressed regions from a 2019 baseline by 2025. [9] As part of setting this goal, we used the World Resource Institute Aqueduct Water Risk Atlas to identify which of our facilities were in water-stressed regions. To date, we have identified six sites throughout California, South Korea, India, and Malaysia.”

To achieve water use efficiency, the ASE Group aligned its actions with the United Nations SDGs for achieving a sustainable economy and environment and adopted the ISO 46001 Water Efficiency Management System. The standard helps the company ensure efficient and sustainable water use by offering guidance in identifying and evaluating major risks and infrastructure improvement opportunities. In 2021, the company’s flagship manufacturing operation, ASE Kaohsiung, received ISO 46001 certification.

The group says they have improved their water recycling projects for their processes and facilities, which included cutting and grinding wastewater, cleaning water, air-conditioning condensate and rainwater recycling, resulting in the reuse of each drop of water more than 3.5 times.

Sigma Engineering: Some Of The Tech Behind Reduced Water Consumption

It’s not just manufacturing facilities putting efforts into water reduction and more sustainable PCB manufacturing practices. Equipment and materials suppliers also are stepping up to the plate.

Focused on helping PCB manufacturers reduce water consumption and transition to a circular economy, Sigma Engineering offers recycling and regeneration systems for PCB industry etching; their Oxidation reactor system for Acidic etchant uses Oxygen gas, replacing other oxidizing agents such as Hydrogen Peroxide, Ozone, or Sodium Chlorate. Along with the environmental benefits come lowered costs and improved quality and safety, claims Sigma.

The Oxidation reactor system removes hazardous waste generated from traditional oxidizing agents, reducing waste transportation and handling costs and enabling tight control of redox potential, steeper flanks, and improved tolerance over temperature, Cu1, Cu2, and HCl concentration. By eliminating the risk of generating chlorine gas that otherwise might occur in the process of using hydrogen peroxide, the oxidation reactor system contributes to a safer workplace.

Conclusion

Clean water is as essential to PCB manufacturing as it is to life. For those in the PCB industry, reducing your company’s water footprint should be as equally important as reducing your carbon footprint.  Optimizing water treatment options and adopting new technologies can enable increased reuse, improve purity levels, and help protect our most precious resource.