Water is essential in the production of microchips and circuit boards, and because so much water is required, engineers rely on water recycling, usually employing sophisticated filtering, but also other means.
At the recent IPC APEX trade show in Anaheim, Calif., at least six small and mid-sized companies out of 400 exhibiting at the show described their treatment efforts, claiming more than 95% of the water can be recycled (some much higher), although none were showing off the actual process other than through diagrams and pictures and referrals to their websites.
One company, ElectraMet of Lexington, Kentucky, displayed copper ingots formed from copper etchings recovered in circuit board production. The company is also involved in EV battery recycling and in recovering copper in semiconductor fabrication. It promotes a way to move towards ZLD (zero liquid discharge) in PCB manufacturing. Mike Lewis, vice president of sales and marketing, said customers are responding to the message out of two motivators: to reduce overall costs and to meet tightening regulatory pressure.
Water recycling and the sustainability trend
Sustainability practices are coming into play moreso recently with circuit boards and other electronics, not only with wastewater recycling but with energy and chemical conservation, said Kelly Scanlon, lead sustainability strategist at IPC, which helps set industry standards for electronics production. “Policies are changing, in particular with laws in the EU,” she said in an interview. “People take action when it’s required of you.”
“We have new requirements coming and reformulation of existing standards. More decisionmakers are talking about sustainability and policymakers are talking about it. It’s business common sense. They say, ‘My customers are asking for this.’They want to work at sustainability. It’s the right thing to do. The ethical thing. Even since last year, more attention is being paid to sustainability.”
Scanlon credited Intel CEO Pat Gelsinger for pushing the sustainability message in the chip production process. She recently heard scientists talk about using physics and chemistry to lower the temperature required to melt solder, which would lower the demand for electricity at a circuit board or chip fab. “It’s not sexy, but it’s important,” she said.
Wastewater is the ‘dirty secret’ in electronics
All the various representatives for wastewater recycling companies at APEX agreed that making PCBs has traditionally been dirty work, although times are changing. PCB production, like chip production, emits billions of liters per day of toxic wastewater globally. It is a toxic soup of heavy metal ions, organic polymer compounds and organic additives that governments have spent decades trying to bring under control. One big reason US electronics companies went abroad in the 1970s for chip and PCB production manufacturing was for cheap labor and to escape US and state environmental laws enacted in a flurry of green activism. Or, to avoid bad publicity, they said.
“Wastewater is the dirty secret in the electronics industry,” said Alexander Stepanski, CEO of Smart Factory Design, speaking from a small display at the Integrated Process Systems booth. Stepanski said he has five customers for his proprietary closed-loop recycling system that reduces harmful discharge to less than 1%. His website adds, “This is achieved by eliminating wastewater discharge and using less water than the bathrooms for the whole PCB shop.”
He did not name his customers, but said one is a rocket maker partly based in Texas. (That could be Elon Musk’s SpaceX, but he did not confirm it is.) Customers pay in the high hundreds of thousands to millions of dollars for the process, which he disclosed includes light and peroxide to destroy organics.
Greensource Engineering names customers
Over at the Greensource Engineering booth, representatives said they are the only company in wastewater treatment for PCBs to have three named customers. They include sister company Greensource Fabrication in Charleston, New Hampshire; Schweitzer Engineering in Moscow, Idaho; and Vicor in Andover, Mass. Greensource offers a patented zero liquid discharge wastewater treatment systems known as ARK (Aqua Regen Kinetics) which is integrated with the company’s wet processing equipment. Like many of the companies exhibiting at APEX, Greensource is hiring engineers, including chemical engineers for its ARK work, said Robert Zajac, software manager for the company.
Elsewhere, Smart Sonic was showing wastewater evaporators, while Seika Machinery was showing a solder waste recycler that converts tin and lead-free solder into usable solder bars. Seika PCB customers in Mexico are seeking the solder re-use to achieve cost savings, but are also feeling the pressure of environmental regulations originating in Europe, said Michelle Ogihara, executive vice president.
Sigma representatives described a Mecer closed loop etchant recycling system for recycling alkaline and acidic etchants and an oxidation reactor system for oxidation of acids in etchings.
How water is used in PCB fabs (and chip fabs)
Etchings or etchants are created in the fabrication of circuit boards after solder paste is applied to a substrate, often made of heat and fire-resistant fiberglass. Components including sensors, inductors, transistors, resistors, capacitors, transformers and diodes are applied to the paste often with high-speed machines. A copper foil layer sits beneath the solder layer and provides the conductive track to connect components for electricity to flow. In sophisticated ovens, including many shown at APEX, the circuit boards are heated at various temperatures to help the solder and copper adhere to components and the substrate. Machines shown by Panasonic Connect, Fuji’s Smart Factory NXTR platform and others can robotically attach hundreds of thousands of components each hour.
After a circuit board is heated with components and solder and copper, it is etched with water and acids such as acetone, creating the wastewater that carries metal filings and other materials that can often be recycled.
The amount of water needed in electronics manufacturing is tremendous by any standard. It takes more than 8 gallons of water to make a single computer chip and 1,100 gallons of water to make a single circuit board, according to one estimate. That results in 5280 gallons of water to make a personal computer, or about 142 standard bathtubs-full of water.
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