Design Life-Cycle

 Yash Girish, Nadge

Group Members:

Nasih Al Barwani

Kyle Taniguchi

DES 040A

Professor Cogdell                             

Raw Materials in a Printed Circuit Board

          Printed circuit boards (PCBs) are a technology that is as prevalent around us like the oxygen in the air. Almost every device we use has one of these, which leads us to the conclusion that the functioning and progress of the world rely on the metals and electricity that run through these tiny pieces. This has become common place knowledge for us - the people living in the 21st century - but if we really think about it for a moment, very important questions arise: Where do the resources to create a technology that is needed in the billions come from? How much energy is consumed? How does this affect the planet? The metals, plastics and fossil fuels that go into this product cannot just be consumed without an impact on the environment.

          I will be answering these very questions through the course of this paper as I have come to realise through my research that the production of any product is an energy intensive process, but a printed circuit board is specially energy intensive because of the large quantity of raw materials that go into making it and the magnitude of production. To make a printed circuit board, you must first provide energy for the manufacture and processing of the raw materials like copper, iron, germanium, etc., for importing certain materials, along with the recycling, re-use, maintenance, and management of the by-products and waste.

          A PCB is an electronic device, which entails that it contains a host of metals to act as conductors and semi-conductors to allow the passage of electricity and even manipulate it to provide different outputs. Metals are found in the earth in combined states, called ores, and need to be physically and chemically altered to be obtained in the form required to produce a PCB. This industrial process of physical and chemical alteration of an ore to give a pure metal as a product is called metallurgy. Metallurgy is a very energy intensive process and requires large plants that use tremendous amounts of fossil fuels to produce heat used to get metals in their molten state and water as a coolant. I will list the metals that go into a PCB below, and further explain how they are obtained:

·       Steel

·       Germanium

·       Copper

·       Nickel

·       Aluminium

·       Gold

          Steel is a metal allow consisting of iron for the most part and carbon and a large amount of oxygen in an electric arc furnace and is used in PCBs due to its rigidity and low thermal conductivity (prevents heating of the circuit board). The iron required for the process is obtained mainly from Brazil (58%), Chile (4%), Sweden (7%), Canada (21%), and a few other countries [1], after the haematite ore (Fe2O3) is purified through a highly exothermic process taking place in a blast furnace with temperatures of around 2000 degrees Celsius, in the presence of carbon, limestone and air. Large amounts of fossil fuels are used in this process as iron melts at severely high temperatures [2], releasing large amounts of gases like carbon monoxide, carbon dioxide, nitrogen, hydrogen, and steam [3]. The carbon used in steel making comes from a natural source: coal. This coal is called metallurgical coal, also known as “metcoal” or coking coal and has a higher purity than thermal coal, which is used in energy generation. Metcoal is heated to about 1100 degrees Celsius to remove water and other chemicals form the steel mix, releasing carbon monoxide (which turns out to be a crucial part of the reaction needed to make steel) [4].

          Germanium is a semi-conductor used in PCBs as part of the microcontroller, as a transistor to manipulate the result obtained from the flow of electricity through the circuit, especially when it is doped (chemically altered by injecting) with a bit of phosphorous or arsenic [5]. The USA maintains greater than 50% reliance on countries like Belgium and China for germanium because Germanium is classified as a critical mineral in the country. Deposits are currently available only in Alaska, Washington, and Tennessee, while a smaller part of it is obtained from the recycling of products such as fibre optics [6]. Since germanium is such an uncommon mineral and is considered a strategic metal for most governmental agencies due to its obvious importance, more ways to extract it have been invented. Zinc ores (60%) and coal fly-ashes have become the leading sources of germanium, from which it is extracted using an energy intensive process, ultimately releasing gases like sulphur dioxide, carbon dioxide and carbon monoxide [7].

          Copper is the second-best electrical conductor (silver being best) and is used in literally every electric wire due to this property of its, along with the fact that it is cheaper to obtain than silver. USA is the second largest producer of copper in the world, but also imports copper from countries like Chile (59%), Canada (24%) and Mexico (11%) [8]. Copper is mainly obtained from sulphide ores of copper, such as chalcopyrite (CuFeS2), through an energy intensive process in furnaces. Purification of copper also leaves us with a mix of the impurities which contain valuable metals like silver and gold sometimes which are used elsewhere, sometimes in electrical circuitry of their own. The most common gas released during this process is sulphur dioxide as the process includes heating up of sulphide ores, but carbon dioxide and carbon monoxides are released again during the process as fossil fuels are required to heat the furnace [9].

          Nickel is very important in the production of a PCB. It isn’t used as a direct component to aid the functioning of the circuit but is instead used as a plating (electroplating) on the PCB. This prevents oxidation of the copper (could cause formation of non-conductive compounds) components, increases tensile strength, resistance to internal stress, fatigue life and prevents chemical corrosion of the metal components. An interesting point to note is that tin can be used for this process too, but nickel is preferred as it has better corrosion resistance than the latter [10]. Nickel production in the nation is very low due to the absence of major nickel reserves, but the country managed to produce about 16,000 tons of nickel in 2020, along with recycled nickel from nickel-based products (consisted of 50 % of consumption). Most of the nickel required for the vast amounts of electronic devices comes from Canada (42%), Norway (10%), Finland (9%), Russia (8%), and a few other countries (31%) [11]. It is obtained in its pure form through an energy intensive metallurgical process, famously known as Mond’s process, on ferronickel and nickel sulphates. Carbon monoxide is released in large quantities during the process btu it is also required for the reaction, so it is released into the environment after being re-used a couple of times [12].

          Aluminium is the most abundant metal in the earth’s crust and is never found in its pure state due to its highly reactive nature. Its components are an important part of PCBs because they transfer heat away from vital components, thus minimizing the harmful effects it could have on the circuit board [13]. It is most found as bauxite or cryolite, which are used in its metallurgical processes. The US imports nearly all the bauxite used in producing primary aluminium from countries like Canada, China, Mexico, UAE, Germany, and India [14]. This bauxite is purified through two very energy intensive processes: Bayer’s process and Hall Heroult’s process. These processes chemically alter the structure of bauxite numerous times until pure aluminium is obtained. I was able to find exactly how much electricity it takes to produce aluminium in the form required for a PCB: 6 -8 KW per hour per pound [15].

          Gold is another metal that greatly improves the conductivity and overall quality of a PCB. Silver and copper have better electrical conductivities than gold, but gold is irreplaceable due to its corrosion resistance (that prevents the increase in resistivity of metals), rigidity (specially in places that can be worn off, like edge connectors), ductility, thermal resistivity and has a system for being recycled in every PCB due to it being highly valuable [16]. USA produced 200 tonnes of gold in 2019, making it the fourth-largest producer of gold in the world [17], but the country still imports large quantities from Switzerland, Canada, Mexico, Singapore, etc [18]. The extraction process occurs from gold’s ore, known most as native gold. This ore is heated to a temperature of about 1064 degrees Celsius (melting point), after which all the chemical alterations are performed on it [19]. It is estimated that 3 – 18 g of gold is obtained for every ton of the ore with 57 – 159 man-hours. The amount of energy used is estimated to be 3501 – 67,325 MJ/100 g of gold, while carbon dioxide emissions are said to be around 398 – 5,240 kg CO2/100 g of gold [20].

          Now that I have provided an idea of the major raw materials, i.e., the conductive materials that go into the inner components of a PCB, I will speak about the materials that constitute the non-conductive part of this electrical device. These might not seem as important as those I’ve mentioned previously, but these ensure the safety of the users of PCBs and also the proper functioning of the device. These are:

·       Nylon 6,6

·       Polyethylene (Plastic)

Nylon 6,6 (also known as polyamide 6,6 or PA66) is a thermoplastic used in the body of the PCB. The non-conductive parts that hold all the components together are constituted of nylon 6,6 and make it safe for the user to handle a functioning PCB. It is highly insulating, corrosion resistant, light, strong and more wear resistant than most popular electronic fasteners [21]. Nylon 6,6 is obtained by the using two materials under high pressure and heat to form a polymer; these are adipic acid (AA) and hexamethylene diamine (HMD). It is estimated that the total energy required to produce Nylon 6,6 is around 7 MJ/hour; a terribly energy intensive process [22].

          Polyethylene (plastic) is a thermoplastic made of similar polymers of ethylene. A PCB that sues polyethylene is called a polyethylene PCB. Polyethylene is highly ductile and dense. It offers low friction and does not absorb moisture, making it a terrific insulator. It does have its own demerits like low strength and melting point, but it is a very economical way to produce PCBs [23]. Polyethylene is prepared through a polymerization process that connect 20 – 100 links of ethylene into one big polymer chain under high temperature and pressure. This process is so terribly energy intensive in fact that it requires about 21 MJ/kg of polyethylene produced. This was about 40 MJ/kg in the recent past, but due to the development of technology, this energy consumption has been halved. But we must remember, not all production plants are modernized, and the amount of energy to produce polyethylene is still 40 MJ/kg [24].

          This brings me to the end of my research. From everything that I have presented, it is very clear to see that the acquisition of raw materials is a very energy and resource consuming process because the materials not only need to be mined from the earth or produced artificially, but they also need to be refined, imported, maintained, recycled, re-used, and disposed of correctly to minimize their harmful effect on the planet. All of this is made possible by the presence of fossil fuels, which are used in every step of the process, be it the heat required for metallurgical processes, fuel for trucks, ships, or planes during transportation, or even to run machines that extract useful components and recycle the product. Printed circuit boards are used in every device we need to run our modern world, but the raw materials that they are based on are the things that truly help us sustain this lifestyle, and with their depleting quantities, carrying on in this haphazard manner of material use looks bleak.

Bibliography

1.     Statista. “Distribution of U.S. Iron Ore Imports by Major Countries of Origin 2016–2019.” Statista, 19 Feb. 2021, www.statista.com/statistics/300496/us-iron-ore-imports-by-major-countries-of-origin.

2.     Libretexts. “Iron Production.” Chemistry LibreTexts, 15 Aug. 2020, chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_and_Websites_(Inorganic_Chemistry)/Descriptive_Chemistry/Elements_Organized_by_Block/3_d-Block_Elements/1b_Properties_of_Transition_Metals/Metallurgy/The_Extraction_of_Iron/Iron_Production.

3.     Wikipedia contributors. “Blast Furnace Gas.” Wikipedia, 6 Oct. 2021, en.wikipedia.org/wiki/Blast_furnace_gas.

4.     “Coking Coal for Steel Production and Alternatives.” Front Line Action on Coal, 29 Nov. 2014, leard.frontlineaction.org/coking-coal-steel-production-alternatives.

5.     AZoM. “Germanium – Properties and Applications.” AZoM.Com, 1 Aug. 2017, www.azom.com/article.aspx?ArticleID=6057.

6.     “Germanium Deposits in the United States - ScienceBase-Catalog.” Sciencebase, 29 Apr. 2020, www.sciencebase.gov/catalog/item/5e87562a82cee42d133ff6b4.

7.     Curtolo, Danilo. “High Purity Germanium, a Review on Principle Theories and Technical Production Methodologies.” Scirp, 22 Aug. 2017, www.scirp.org/journal/paperinformation.aspx?paperid=78624.

8.     Statista. “Distribution of U.S. Copper Imports by Country of Origin 2016–2019.” Statista, 16 Feb. 2021, www.statista.com/statistics/254877/us-copper-imports-by-major-countries-of-origin/#:%7E:text=Distribution%20of%20U.S.%20copper%20imports%20by%20country%20of%20origin%202016%2D2019&text=Between%20206%20and%202019%2C%20around,allies%20for%20the%20United%20States.

9.     ---. “The Extraction of Copper.” Chemistry LibreTexts, 7 June 2021, chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_and_Websites_(Inorganic_Chemistry)/Descriptive_Chemistry/Elements_Organized_by_Block/3_d-Block_Elements/1b_Properties_of_Transition_Metals/Metallurgy/The_Extraction_of_Copper.

10.  Lesley. “What Is the Purpose of Plating Nickel on PCB? - PCB Manufacturing Information - PCBway.” Pcbway, 6 Aug. 2020, www.pcbway.com/blog/PCB_Manufacturing_Information/What_is_the_Purpose_of_Nickel_Plating_on_PCB_.html#:%7E:text=The%20main%20purpose%20of%20plating,cracking%20of%20conductivity%20and%20solderability.

11.  Government Publishing Office and Government Publishing Office. Mineral Commodities Summary 2021. U.S. Government Printing Office, 2021.

12.  ---. “Mond Process.” Wikipedia, 4 June 2021, en.wikipedia.org/wiki/Mond_process.

13.  White, Jason. “Advantages of Using Aluminum in Printed Circuit Board Manufacturing.” PCB Solutions, 7 June 2016, pcb-solutions.com/blog/printed-circuit-boards/advantages-using-aluminum-printed-circuit-board-manufacturing.

14.  Workman, Daniel. “US Aluminum Imports by Supplying Country.” World’s Top Exports, 23 July 2021, www.worldstopexports.com/us-aluminum-imports-by-supplying-country.

15.  “Aluminium.” Virtual Chembook, chemistry.elmhurst.edu/vchembook/327aluminum.html. Accessed 1 Dec. 2021.

16.  “Why Use Gold Rather Than Silver And Copper in PCB Fabrication?” PCBgogo, 16 Oct. 2019, www.pcbgogo.com/blog/Why_Use_Gold_Rather_Than_Silver_And_Copper_in_PCB_Fabrication_.html.

17.  ---. “Gold Mining in the United States.” Wikipedia, 23 Nov. 2020, en.wikipedia.org/wiki/Gold_mining_in_the_United_States#:%7E:text=In%202019%20the%20United%20States,behind%20China%2C%20Australia%20and%20Russia.

18.  Workman, Daniel. “Gold Imports by Country.” World’s Top Exports, 31 May 2021, www.worldstopexports.com/international-markets-for-imported-gold-by-country.

19.  “Gold Processing.” Encyclopedia Britannica, 26 July 1999, www.britannica.com/technology/gold-processing.

20.  Cenia, Marie Chela. “Life Cycle Energy Use and CO2 Emissions of Small-Scale Gold Mining and Refining Processes in the Philippines.” The International Journal of Life Cycle Assessment, 18 Dec. 2017, link.springer.com/article/10.1007/s11367-017-1425-5?error=cookies_not_supported&code=cc8d6163-ddc4-4809-903b-fa05b7b94e85.

21.  Adminelectron. “Nylon Hardware in the Fastener World.” Electronic Fasteners, Inc., 13 July 2018, www.electronicfasteners.com/nylonhardware/#:%7E:text=Nylon%20is%20especially%20popular%20for,insulating%20value%20and%20corrosion%20resistance.&text=For%20example%2C%20nylon%20circuit%20board,board%20components%20to%20the%20board.

22.  Jacobson, David Wallace, "An industrial process for the production of nylon 6 6 through the step-growth reaction of adipic acid and hexamethylenediamine" (2017). Chemical Engineering Undergraduate Honors Theses. 104. http://scholarworks.uark.edu/cheguht/104

23.  “Polyethylene for PCB Boards - PCB Directory.” PCBDirectory, 14 Sept. 2019, www.pcbdirectory.com/community/polyethylene-for-pcb-boards.

24.  “Learn | OpenEnergyMonitor.” Learn, 5 Jan. 2018, learn.openenergymonitor.org/sustainable-energy/energy/industry-plastic.

Nasih Al-Barwani 

Yash, Kyle 

DES 040A 

Professor Cogdell 

Printed Circuit Board: Embodied Energy 

A printed circuit board is a framework that houses electrical circuitry made up of traces,  which are embedded metal lines, and planes, which are larger metal sections. Printed circuit  boards are utilized in a wide range of applications. Simple circuit boards are found in toys and  controllers, whereas complex ones are found in computers and telecommunications  (Introduction). To make the circuit board, you would need to get the raw materials processed  using electrolysis, the blast furnace, reduction, and many other processes, which would require  massive amounts of energy; however, the manufacturing process uses the most energy in the  cycle through drilling, scrubbing, UV baking, etching, electrolytic plating, soldier masking and  many other important processes that would be required to make the circuit board and we always  look for ways to reduce to the energy needed and waste for the cycle (You-Jin and Gyu-Bong). 

Circuit boards need massive amounts of energy to extract raw materials whether it is  through mining them or processing them to become secondary raw materials. It is important to  study the energy used in the extraction of raw materials to find ways to maximize efficiency and  minimize toxic waste during the extraction of raw materials. First, the ores that need to be mined  before being processed are collected through the burning process of fossil fuels which releases  massive amounts of chemical energy that was stored in the fossil fuel into the air. To process the  raw materials into secondary raw materials, electrical energy is required to do so in almost every 

Al-Barwani 2 

case due to its efficiency. If electricity is used, then thermal energy or heat will also be released.  When the secondary raw materials are formed, the materials are then used to manufacture the  circuit board. 

Manufacturing circuit boards need more energy than the extraction process as they would  go through many manufacturing processes to complete the circuit board. When manufacturing the circuit board. When manufacturing the circuit board, thermal energy is often used to couple  electric components into a circuit board to make the printed circuit boards heating component (Luhe and Muirhead). Radiant energy is used in the manufacturing process to make use of the  ultraviolet radiation which is used in UV baking (J.M.K.C Donev et al). The use of electrical  energy is mostly used to make the manufacturing process the most efficient. Some of the  manufacturing processes such as scrubbing are used to remove waste from the manufactured  product which requires massive amounts of electricity which therefore means it requires vast  amounts of energy (Horton). There are many other processes that are required to manufacture a circuit board that uses large amounts of energy. The circuit boards consist of many components  inside it such as resistors, transformers, capacitors, sensors and much more. When the  manufacturing process is completed the finished circuit board would then be transported. 

Transporting the materials would require the least amount of energy, and the amount of  energy used is not that large compared to the large energy amounts used during extraction and  manufacturing processes. However, even though the embodied energy of transportation is one of  the lowest in the life cycle, it still does take a huge amount of energy to transport the finished  circuit board because petroleum is the main source of energy for transportation; gasoline, natural  gas, propane, biofuels, and electricity is also an energy source for transporting the materials  (“Use of Energy fir Transportation – U.S Energy Information Administration (EIA)”). 

Al-Barwani 3 

Transporting the materials does not require many processes like the extraction of raw materials  and manufacturing the circuit boards, but it still requires a decently large amount of energy. After the circuit board has been transported, the consumer would then create electric devices  using the circuit board. 

People use electric devices every day; therefore, the circuit board would release energy  every second it is used. Since the circuit board is installed in electric devices, the primary source  of energy would. The foundation of the circuit board is a resistor; it restricts or controls the flow  of electrical current by converting voltage into heat; hence, it can be said that it releases variable  amounts of thermal energy that are reliant on the current of electricity flowing through the circuit  board. The circuit board also has a battery that stores chemical energy; then, the energy is  eventually converted into electricity. Inductors found in the circuit boards use a magnetic field to  store the energy before it dissipates into other parts. People use several sensors in their daily  lives nowadays, whether it be a temperature sensor or a light sensor in a phone's camera; these  sensors are found in the circuit board. The sensors detect light energy, thermal energy, kinetic  energy, and many other energies and convert them into electrical energy (Gong). The demand for  circuit boards is high, so companies must respond to them with high supply; as a result of that,  companies researched ways to make production faster and less toxic. 

The extraction, manufacturing, and transportation processes all create tons of energy per  waste every year. The burning of fossil fuels to produce electricity releases chemical energy and  thermal energy into the hair creating a polluting environment. Combustion is one of the causes of  global warming because we rely heavily on fossil fuels to produce electricity. Transportation also  releases vast amounts of chemical energy into the air since it is heavily reliant on petroleum.  Electricity can also be produced by nuclear power, and they use a turbine to transfer heat energy 

to kinetic energy, which then is used to convert into electricity. Although the process might be  safe, if an accident occurs, the waste produced by nuclear power is dangerous as it still contains  radioactive energy and is harmful to the environment as it releases tons of radioactive energy  into the atmosphere (“Fossil Fuels and Nuclear Power - Revision 2 - GCSE Physics (Single  Science) - BBC Bitesize”). The overall efficiency of a modern fueled electrical powerplant is  about 40%. By looking at this percentage, we would notice that most of the energy released by  fossil fuels is going to waste, and this is a major factor in global warming. Therefore, people look  for ways to reduce the burning of excess fossil fuels. (Lawson). 

Many manufacturers and companies looked for ways to make manufacturing faster, more  efficient, and reduce toxic waste. They concluded that they would recycle some materials or  products and use them to produce circuit boards. Most circuit boards are made with copper since  it is one of the best conductors of electricity. However, to get copper, you would need to go  through smelting ores and other energy-intensive processes. If people use this method every time  they produce a circuit board, it will cost a vast amount of energy to produce a few circuit boards.  Therefore, businesses and manufacturers began recycling copper and other materials from other  products like wires, chips, and other products that contain copper. In 2014, 34% of domestic use  of copper in the US was from recycled products, and they recycled about 820,000 metric tons of  copper. Recycling copper saved from 85 to 90 percent of energy requirements (LeBlanc). The  amount of energy saved by recycling other materials is almost the same for different materials.  We can say by looking at the statistics that recycling is necessary and is one of the ways to  reduce waste. 

The energy required in transporting the finished product may be immense, but extracting  the raw materials is more extensive; however, in most cases, the manufacturing process has the 

most embodied energy in the life cycle. When extracting raw materials and manufacturing them,  it releases massive amounts of chemical energy into the air since the primary source of energy is  electricity and to produce electricity, we need to burn fossil fuels; therefore, it harms the  environment and is one of the reasons for global warming. Therefore, to reduce toxic waste,  companies and manufacturers started using recycled products to reduce the amount of energy  being released into the environment.

1) Hudson, Glyn. “Investigating the Embodied Energy of the EmonPi & Oscedays  London 

12-14th June.” Blog, https://blog.openenergymonitor.org/2015/06/investigating 

embodied-energy-of-emonpi/ 

2) Wang, Xue, and Gabrielle Gaustad. “Prioritizing Material Recovery for End-of-Life Printed  Circuit Boards.” Waste Management, vol. 32, no. 10, Oct. 2012, pp. 1903–1913,  10.1016/j.wasman.2012.05. 005.. 

3) Weiser, Roberto. “Can You Recycle a PCB? - Developpa Electronics.” Developpa, 20 June  2018, https://developpa.io/recycle-pcb/.  

4) “What Is PCB Ground Plane and How Is It Used in Your Design?” Absolute Electronics  Services, 22 Aug. 2021, https://absolutepcbassembly.com/what-is-pcb-ground-plane/. 

5) “Microwave Circuit and PCB Design - Engineering Technical - PCBway.” Www.pcbway.com,  www.pcbway.com/blog/Engineering_Technical/Microwave_circuit_and_PCB_design.ht ml.  

6) Luhe, Friedrich von der, and William Muirhead. Electric PCB Heating Component, Electronic  Circuit Board and Heating Method.  

https://patents.google.com/patent/US20060289464A1/en.  

7) Lee, Gyu-Bong, et al. “Analysis of Energy Efficiency in PCB Manufacturing Process.”  International Journal of Precision Engineering and Manufacturing, vol. 13, no. 7, July 2012, pp. 1215–1220, 10.1007/s12541-012-0161-9. .  

8) Yung, Winco K. C., et al. “Chapter 13 - Carbon Footprint Analysis of Printed Circuit Board.”  ScienceDirect, Butterworth-Heinemann, 1 Jan. 2018,  

www.sciencedirect.com/science/article/pii/B9780128128497000131. .  

9) Dong, Yue, et al. “Sustainable Additive Manufacturing of Printed Circuit Boards.” Joule, vol.  2, no. 4, Apr. 2018, pp. 579–582, 10.1016/j.joule.2018.03.015. 

10) “New Scavenger Technology Allows Robots to ‘Eat’ Metal for Energy.” Electronics  Manufacturing News - Printed Circuit Boards Manufacturing News, 21 Apr. 2020, 

https://globalsmt.net/new-scavenger-technology-allows-robots-to-eat-metal-for energy/?v=7516fd43adaa.  

11) “Use of Energy for Transportation - U.S. Energy Information Administration (EIA).”  Eia.gov, 2016, www.eia.gov/energyexplained/use-of-energy/transportation.php. 

12) Horton, Jennifer. “How CO2 Scrubbing Works.” HowStuffWorks, 28 July 2008,  science.howstuffworks.com/environmental/green-science/co2-scrubbing.htm

13) J.M.K.C. Donev et al. “Ultraviolet Radiation - Energy Education.” Energyeducation.ca,  2019, energyeducation.ca/encyclopedia/Ultraviolet_radiation. 

14) Park, You-Jin & Lee, Gyu-Bong. (2013). Analysis of Energy Efficiency and Productivity in  Dry Process in PCB Manufacturing. International Journal of Precision Engineering and  Manufacturing. 14. 10.1007/s12541-013-0165-0. or You-Jin, Park, and Lee Gyu-Bong.  “International Journal of Precision Engineering and Manufacturing.” Analysis of Energy  Efficiency and Productivity in Dry Process in PCB Manufacturing, 1 July 2013,  www.researchgate.net/publication/257787391_Analysis_of_Energy_Efficiency_and_Pro ductivity_in_Dry_Process_in_PCB_Manufacturing/citation/download.

15) “Hydrogen Production: Electrolysis.” Energy.gov, www.energy.gov/eere/fuelcells/hydrogen production 

electrolysis#:~:text=Electrolysis%20is%20the%20process%20of%20using%20electricity %20to 

16) Introduction, An. “Printed Circuit Board: An Introduction and the Basics of Printed Circuit  Boards.” Cadence.com, Printed Circuit Board: An Introduction and the Basics of Printed  Circuit Boards, 27 Sept. 2019, resources.pcb.cadence.com/blog/2019-printed-circuit board-an-introduction-and-the-basics-of-printed-circuit-boards. 

17) Lawson, Barrie. “Electrical Power Generation from Fossil Fuels.” Www.mpoweruk.com,  2005,  

www.mpoweruk.com/fossil_fuels.htm#:~:text=Taking%20into%20consideration%20the %20three%20conversion%20processes%2C%20thermal%2C.  

18) Gong, Peter. “What Are the Parts of a Circuit Board?: A Detailed Discussion.” FX PCB, 30  Sept. 2020, sfxpcb.com/what-are-the-parts-of-a-circuit-board/.  

19) LeBlanc, Rick. “The Facts on Copper Recycling.” The Balance Small Business, 26 Mar.  2019, www.thebalancesmb.com/facts-about-copper-recycling-2877923.

20) “Fossil Fuels and Nuclear Power - Revision 2 - GCSE Physics (Single Science) - BBC  Bitesize.” BBC Bitesize, 2020, www.bbc.co.uk/bitesize/guides/z2d2bk7/revision/2.

 Kyle Taniguchi 

Nasih Al-Barwani, Yash Nadge

DES 40A

Professor Cogdell

Waste and Emissions of Circuit Board

Circuit boards are an essential centerpiece of today’s technology. Most consumer electronics, such as computers and smartphones, cannot function without a circuit board. It is an important component that controls all of the activities that take place in the system. It connects all the parts of a computer such as CPU, memory, optic drivers, video cards, and other essential parts. Circuit boards are so crucial, that many may say it is the backbone of electronics. 

Though it is one of the smaller components, it is composed of many materials and parts. These are commonly known materials, such as copper and tin. The production of circuit boards and their afterlife contains many wastes and byproducts that could be recycled and reused, but are often overlooked. 

Raw materials are materials that need to be extracted from the ground. Circuit boards include raw materials such as copper, tin, aluminum, and silicon. There are two different kinds of mining; surface mining and underground mining. Surface mining includes blasting ground for the materials. Underground mining, on the other hand, requires mines to go deep under surface level to extract the material. For both of these methods, the land needs to be modified for large amounts of materials to be taken. 

Material extraction and production emits toxic byproducts harmful to the environment. Mining for raw materials damages the surrounding environment in many ways. Creating large mining locations can drastically alter the shape and atmosphere of the landscape. Change in the land is not only harmful, but it can take away long preserved, beautiful scenery and national infrastructures. 

Visible damage is not the only effect mining has to the surrounding area. According to research by the University of Bangka Belitung, Indonesia, mining of metals can decrease the water pH by 25 percent. Even the slightest change of pH can drastically change what organisms can survive or die. Sand can also fragment 97 percent and soil temperature can go up to 45 percent. This can lead to major deforestation and loss of vegetation in the long run. 

Fumes and other materials enter the internal organs of workers, causing various health risks and issues. These “dust” or particular matters, are usually microscopic and oftentimes hard to see with the human eyes. When this particle matter enters the respiratory system, it sticks to the airways and causes long-term breathing problems. According to the CDC, Center for Disease Control, 75,178 miners died from CWP in the year 2016. CWP, also known as Coal Miners Pneumoconiosis, is a fatal disease where coal and other particles get stuck inside a worker’s lung, causing inflammation and scarring. 

Once the material is extracted for the Earth, it needs to be transported.  Most mining and material extraction occurs in countries such as Australia, China, and Africa. However, factories that put together these circuit boards are located in Taiwan or the United States. The top leading circuit board companies, Unimicron and DSBJ, have their headquarters and markets in Taiwan and China. This means that material and the finished products need to be carried across seas. Primary transportation of raw and secondary materials are huge cargo ships and trucks. The EPA, United States Environmental Protection Agency, claims that in the year 2019, greenhouse gas emissions from transporting products accounted for 29 percent of the total greenhouse gas emission in the U.S. Most of the gas comes from burning fossil fuel, as over 90 percent of the fuel used is petroleum-based. 

Once primary materials are collected, the circuit board is put together. Secondary materials, materials that require processed raw materials, are put together in this process. Fiberglass and plastic are the main secondary materials used in circuit boards.

Plastics today are made synthetically due to their ease of manufacturing. The materials required are crude oil, natural gas, and coal. The production process goes through refining the materials, polymerization, and compounding(Baheti, 2021). In the year 2018, Nearly 360 million tons of plastic were produced (Knoblauch 2020). The production of plastic emits byproducts such as sulfur oxide, nitrous oxides, methanol, and other volatile organic compounds. These chemicals are extremely dangerous, sulfur oxide, for example, combines with water in the rain and comes down as acid rain. 

Fiber Glasses are glasses similar to windows but refined to a very thin sheet. To make fiberglass, glass is heated until molten, then forced through thin holes (Johnson, 2020). Resins and other enforcement are then added to the glass to make it more durable. This results in an extremely light, yet durable glass. Like normal glass, fiberglass requires sand to create. Resin is used in the production of fiberglass. It keeps the material strong and resistant to wear and tear. However, it also causes a great deal of harm to the environment. It emits toxic air pollutants such as styrene, a colorless flammable liquid. This evaporates during the curing processes and forms ground-level ozone. Other materials such as paints, thinners, solvents, and adhesives can also cause similar effects (EPA, 2005).

With primary and secondary materials ready, the circuit board is constructed. Circuit boards start off with putting the materials together into a thin board. It is then cut into the ideal shape using a laser cutter. The cut sheets are put into layers and laminated with plastic or fiberglass. After the layering process, all unwanted metals are cut off and connections are made on the board. 

The assembly of the circuit board emits byproducts. Hydrochloric acid sodium chlorate, and hydrogen peroxide are some acidic byproducts of producing circuit boards. Not only does it come down as acid rain and decompose various things, it changes the characteristics of land, making plants hard to grow. 

The machine used to produce the boards operates off of electricity, which is a secondary source that comes from fossil fuel. The U.S. The Energy Information Administration states that in the year 2018, more than 90 percent of petroleum and coal were used in manufacturing. The byproduct of the process was mostly waste gas or greenhouse gas, making up for 96 percent of the total emission. 

After the production process is complete, the circuit board is put in. Since circuit boards come and go with their electronic counterparts, their lifespan as well as their energy use is usually associated with the electronic devices’ lifespan. Smartphones usually last about two to three years and take up about 7kWh/year for charging and operating. Laptops and computers last anywhere between 2-7 years and it takes about 40 kWh/year for charging and operating. 

Electricity is a secondary energy source. It comes from primary energy sources such as coal and fossil fuel. However, the efficiency of the energy source is less than 50 percent. The efficiency for coal is 35 percent, 45 percent for natural gas, and 38 percent for fossil fuel (Zeiss, 2010).

Once the time of use comes, circuit boards go to waste. Plastic makes up the majority of the circuit board, making up for most of the waste related to the circuit boards afterlife. According to the National Geographics, 8 million tons of plastics are released into the oceans every year. Once these plastics are released into the oceans, it takes more than 400 years to fully decompose (Parker, 2019). Plastic in oceans not only disrupts the purification process of water, it enters and stays in the sea creature’s internal systems. 

Fiberglass has very similar characteristics to plastic and its damage to the environment acts almost the same. Despite the short lifespan, fiberglasses stay in the landfill for more than 50 years, sitting and unable to decompose.

Raw materials such as copper and tin are also thrown into the dump. Rare metals such as copper and tin used in circuit boards mostly end up in the dump, despite being scarce. The rare metals used in electronics today are recycled zero percent. The increase in demand for these metals is drastically increasing while the supply is drastically decreasing. 

Not all hope is lost. Reducing, reusing, and recycling these materials can substantially cut waste emissions. One way of reducing the waste of circuit boards is simply reusing the board. Since the life of an electronic device is often correlated to the life of a circuit board, the circuit board is thrown away, despite still being useful. Taking apart the electronic device and using the circuit board is the most cost-efficient and environmentally friendly method of lessening waste. 

However, in some cases, the circuit board simply cannot be reused. To recycle the circuit board, materials must be taken apart. A special machine called the “PCB board recycling machine” first crushes and takes the circuit board apart using electrostatic separation. Once individual components are acquired, the material can be used to produce other products that require these rare metals and parts. Fiberglass and plastic need to be processed after extraction to be returned to their usable form. They go through a process called pyrolysis, where materials are heated up to high temperatures in an oxygen-depleted environment. The result of this is gas, oil, and solid. The oil is used for fuel and asphalt and gas are used as a replacement for natural gas fuel burners. The solid component can be reused for objects such as boats and playground structures. 

Changing the material can also lessen the impact on the environment. For the production of fiberglass and plastic, replacing resin and gel coats with ones containing less styrene can decrease the emission of volatile organic compounds. Bioplastics or plastic made from cornstarch, as well as biodegradable plastics (Gibson, 2016), can replace the traditionally used plastic to help the environment not only during production but after its use.

The production of a circuit board includes many primary raw materials and secondary materials that either need to be extracted, processed, or modified. Each stage in the life of circuit boards can bring harm to the environment. Noticing these points and reducing reusing, and recycling can help lessen the damage it does to the Earth. The future goal of the circuit board must focus on closing the life of the circuit board and bringing the waste back into use. 

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