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intro_pcb [2026/06/05 17:18] – [State of the art: environmental impacts] lucas.burlot.extintro_pcb [2026/07/07 15:56] (current) – [State of the art: environmental impacts] lucas.burlot.ext
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 | **Scope** | Cradle-to-grave | Cradle-to-waste | Board fab + manufacturing | Gate-to-gate / Cradle-to-gate | Cradle-to-gate | | **Scope** | Cradle-to-grave | Cradle-to-waste | Board fab + manufacturing | Gate-to-gate / Cradle-to-gate | Cradle-to-gate |
 | **Use phase** | Excluded | Excluded | Excluded | Excluded | Excluded | | **Use phase** | Excluded | Excluded | Excluded | Excluded | Excluded |
-| **Technology** | FR-4, PET, paper, multilayer | FR-4 vs paper P-PCB | FR-4 single-layer | FR-4 PTH, all stackups | FR-4, 6Layers SMT | +| **Technology** | FR-4, PET, paper, multilayer | FR-4 single-layer | FR-4 vs paper P-PCB | FR-4 PTH, all stackups | FR-4, 6Layers SMT | 
-| **Key GWP hotspot** | Epoxy resin, layer count | Copper (O-PCB); silver (P-PCB) | Etching (FAETP, ODP); copper in board fab | Electricity consumption (~86% of GHG) | Electricity (~45% GWP) | +| **Key GWP hotspot** | Epoxy resin, layer count | Etching (FAETP, ODP); copper in board fab | Copper (O-PCB); silver (P-PCB) | Electricity consumption (~86% of GHG) | Electricity (~45% GWP) | 
-| **GWP order of magnitude** | ~3–11 kg CO₂eq/25 cm² | 39.2 kg CO₂e/m² (O-PCB) | 18.6 kg CO₂e/m² | 60–200 kg CO₂e/m² (company range) | 200 kg CO2eq/m² |+| **GWP order of magnitude** | ~50–500 kg CO₂eq/m² | 18.6 kg CO₂e/m² | 39.2 kg CO₂e/m² (O-PCB) | 60–200 kg CO₂eq/m² (company range) | 200 kg CO2eq/m² |
  
   * **Liu et al. (2014)** — //Future Paper-Based Printed Circuit Boards for Green Electronics: Fabrication and LCA[(liu>[[https://pubs.rsc.org/en/content/articlelanding/2014/ee/c4ee01995d | Liu, Jingping & Yang, Cheng & Wu, Haoyi & Lin, Ziyin & Zhang, Zhexu & Wang, Ronghe & Li, Baohua & Kang, Feiyu & Shi, Lei & Wong, C.P.. Future Paper based Printed Circuit Boards for Green Electronics: Fabrication and Life Cycle Assessment. Energy Environ. Sci.. 7 (2014). https://doi.org/10.1039/C4EE01995D. ]])]//   * **Liu et al. (2014)** — //Future Paper-Based Printed Circuit Boards for Green Electronics: Fabrication and LCA[(liu>[[https://pubs.rsc.org/en/content/articlelanding/2014/ee/c4ee01995d | Liu, Jingping & Yang, Cheng & Wu, Haoyi & Lin, Ziyin & Zhang, Zhexu & Wang, Ronghe & Li, Baohua & Kang, Feiyu & Shi, Lei & Wong, C.P.. Future Paper based Printed Circuit Boards for Green Electronics: Fabrication and Life Cycle Assessment. Energy Environ. Sci.. 7 (2014). https://doi.org/10.1039/C4EE01995D. ]])]//
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 **Limitations** **Limitations**
 The dataset carries several significant limitations, most of which compound over time: The dataset carries several significant limitations, most of which compound over time:
-Temporal and technological representativeness: Primary data sourced from AT&S AG (2006), US EPA (1995/2000), and ZVEI (2006). Given the pace of process optimisation in PCB manufacturing — particularly energy efficiency and chemical management — this nearly 20-year-old data is likely to overestimate current consumption intensities. This is explicitly flagged as a concern.+Temporal and technological representativeness: //Primary data sourced from AT&S AG (2006), US EPA (1995/2000), and ZVEI (2006). Given the pace of process optimisation in PCB manufacturing — particularly energy efficiency and chemical management — this nearly 20-year-old data is likely to overestimate current consumption intensities. This is explicitly flagged as a concern//.
 Electricity mix: The dataset uses the Global electricity mix. Users can adapt the electricity mix by copying and editing the dataset in SimaPro or similar tools, but this requires awareness and additional effort. Electricity mix: The dataset uses the Global electricity mix. Users can adapt the electricity mix by copying and editing the dataset in SimaPro or similar tools, but this requires awareness and additional effort.
-Gold and surface finish: Since gold (ENIG finish) contributes ~60% of ADP-e, applying this dataset to PCBs without a gold finish (which is common) introduces a significant and hidden overestimation of mineral resource depletion impacts. The dataset can be manually corrected by subtracting the gold flow, but this is not transparent to naive users. +Gold and surface finish: As the amount of gold in the PCB is a key contributor to environmental impact, there is a need for precise gold quantity in PCB for an accurate LCA. Also, for PCBs without a gold finish there is an important “hidden burden” by using this dataset, though it is possible to copy the dataset and subtract the gold if needed 
-Material proxies: Several key materials are represented by proxies of varying quality — glass-fibre reinforced polyester for cores/prepreg, phenolic resin for solder mask and resist, LLDPE for defoamer — introducing uncertainty in the upstream burden calculation. +. 
-Geographic extrapolation: Data from 2–3 European producers (AT&S AG Leoben and Fehring plants, hmp, SEAG) are extrapolated as "global average," which is methodologically questionable given that European production represents a small and likely more tightly regulated share of world output. +###Other information on impact assesment :
-Missing flows: No VOC speciation beyond NMVOC; no DOC/TOC in water emissions; no Pb air emissions in the Pb-free dataset; partial coverage of process chemicals for the THT board (~2/3 reported as an unspecified aggregate, disaggregated by assumption). +
-Scope exclusions: Component mounting, integrated circuit manufacturing, use phase, end-of-life, and recycling are all out of scope. These are covered in other Ecoinvent report No. 18 modules but must be explicitly linked by the LCA practitioner. +
- +
-#### Impact assesment of PCBs in the EcoInvent database +
- +
-__Impact assessment methods used (EF, ReCiPe, others)__: +
- +
-The Environnemental Footprint 3.1 method is used here. +
- +
-__Environmental impacts associated to the system (indicators)__: +
- +
-From the EcoIvent data "printed wiring board production, for surface mounting, Pb free"[(ecoinvent>https://ecoquery.ecoinvent.org/3.11/cutoff/dataset/9764/documentation)] +
- +
-Considering the EF Single Score, the environnemental indicators that contributes the most to at least 80% of the single score are : +
-  - Resource use, minerals and metals +
-  - Climate change +
-  - Eutrophication, freshwater +
- +
-__Known hotspots, raw materials, life stage__: +
- +
-Taking the Econinvent dataset and documentation and Hischier R. et al. 2007 of the "printed wiring board production, for surface mounting, Pb free surface"[(ecoinvent)]. +
-The dataset is baseb on a 1.6 mm thick 6-layer PWB with a mixture of several Pb-free surface finishing methods and a weight of a weight of 3.26 kg/m². +
- +
-For 1m², using PEF3.1 and  Simapro. +
-Electricity consumption is the main contributor to GWP. +
- +
-Gold, copper and electricity consumption are the main contributors to the single score. +
- +
-* Processes +
-    * PCB factory +
- +
-* Energy use +
-    * Electricity +
- +
-Data needed from manufacturer : +
- +
-* production volume +
-* line capacity +
-* installed power +
-* water usage+
  
 Another known hotspot in the manufacturing process is the etching steps [(ozkan>[[https://link.springer.com/article/10.1007/s11356-017-0280-z | Ozkan, E., Elginoz, N. & Germirli Babuna, F. Life cycle assessment of a printed circuit board manufacturing plant in Turkey. Environ Sci Pollut Res 25, 26801–26808 (2018). https://doi.org/10.1007/s11356-017-0280-z]])]. This manufacturing step requires numerous successive operations, thus having a high energy footprint. It consumes a high quantity of chemical elements, that are present in the resulting waste water. It contributes to almost all the impact for the Fresh Aquatic Ecotoxicity Potential, Ozone Depletion Potential, and  Fresh Aquatic Ecotoxicity Potential indicators. The main contributors to these impacts are the incineration of copper and the chloride acid consumption. Another known hotspot in the manufacturing process is the etching steps [(ozkan>[[https://link.springer.com/article/10.1007/s11356-017-0280-z | Ozkan, E., Elginoz, N. & Germirli Babuna, F. Life cycle assessment of a printed circuit board manufacturing plant in Turkey. Environ Sci Pollut Res 25, 26801–26808 (2018). https://doi.org/10.1007/s11356-017-0280-z]])]. This manufacturing step requires numerous successive operations, thus having a high energy footprint. It consumes a high quantity of chemical elements, that are present in the resulting waste water. It contributes to almost all the impact for the Fresh Aquatic Ecotoxicity Potential, Ozone Depletion Potential, and  Fresh Aquatic Ecotoxicity Potential indicators. The main contributors to these impacts are the incineration of copper and the chloride acid consumption.
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 * Type of surface finish * Type of surface finish
  
-__Main source of uncertainty__: 
-About the Ecoinvent PWB dataset : 
-Time and technological representativeness of this dataset is probably very low as it is sourced from AT&S AG (2006), US EPA (2000) and ZVEI (2006). 
-  
-PCB technologies as well as manufacturing technologies might have change or been optimized since then.  
- 
-As electricity consumption is a key contributor to environmental impact, there is a need for up-to-date electricity intensity of PCB production.  
-Electricity location is an important factor, providing datasets with the most common location (China, South Est Asia, EU, USA, …?), though it is currently possible to copy the dataset and adapt the electricity mix of if the location is known. 
  
-Considering finish separately + By proposing a parametric LCA, like choosing between finish types and electricity mixes, we should allow easier and better assesment of the PCB.
-As the amount of gold in the PCB is a key contributor to environmental impact, there is a need for precise gold quantity in PCB for an accurate LCA.  +
-Also, for PCBs without a gold finish there is an important “hidden burden” by using this dataset, though it is possible to copy the dataset and subtract the gold if needed.+
  
- By proposing a parametric LCA, like choosing between finish types and electricity mixes, we should allow easier and better assesment of the PC +## Life cycle Inventory (⚠️WORK IN PROGRESS⚠️)
-B +
-## Life cycle Inventory+
 [comment]: <> (=> Goal: Define state of the art on life cycle stages to be considered.) [comment]: <> (=> Goal: Define state of the art on life cycle stages to be considered.)
 [comment]: <> (### Database and tools) [comment]: <> (### Database and tools)
-[comment]: <> (#### What are the already existing data (dataset, parametric model, paper, etc.))+[comment]: <> (#### What are the already existing data (dataset, parametric model, paper, etc.)
  
 ### Raw materials ### Raw materials
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 A PCB is composed of a succession of copper, substrate, and pre-preg layers. [(substrate_types>https://www.proto-electronics.com/blog/characteristics-details-and-types-of-pcb-substrates)] A PCB is composed of a succession of copper, substrate, and pre-preg layers. [(substrate_types>https://www.proto-electronics.com/blog/characteristics-details-and-types-of-pcb-substrates)]
  
-The type of substrate material varies depending on the target application of the PCB. The main substrate materials are [(pcb_types_cadence>https://resources.pcb.cadence.com/blog/er-part-1-pcb-substrates-the-truth-about-cost-vs-performance-in-2025)] +The type of substrate material varies depending on the target application of the PCB. The main substrate materials are 
-[(substrate_types)]+[(pcb_types_cadence>https://resources.pcb.cadence.com/blog/er-part-1-pcb-substrates-the-truth-about-cost-vs-performance-in-2025)], 
 +[(substrate_types)],
 [(nextpcb)]: [(nextpcb)]:
   * FR-4:  It is the most common PCB subtrate material. It is composed of epoxy resin reinforced by glass fibers. It has the property to be resistant to fire, water and moisture. The main elements in the glass fibers are silicon dioxide, calcium oxide, aluminum oxide, boron oxide, sodium/potassium oxide, magnesium oxide, iron oxide, titanium oxide, and fluoride, appearing in a decreasing order of concentration[(https://www.viasion.com/blog/what-is-fr4-material-properties-constituents-and-fabricate-steps/)]. The epoxy resin contains an epoxide group, made of two carbon and one oxygen atoms. The most common epoxy material is the DGEBA one, containing carbon hydrogen, chloride and oxygen[(https://resiners.com/blogs/resiners-guide/chemical-formula-of-epoxy?srsltid=AfmBOooBqMoahxKAUb9Ne2xNiQyvRCzmNBMTQ-1Pw-QS64I7LKNr25H2)]. Some derivatives exist, including one resistant for high temperature, using glass with higher fusion temperature [(substrate_types)]. The abreviation FR stands for Flame Retardant.    * FR-4:  It is the most common PCB subtrate material. It is composed of epoxy resin reinforced by glass fibers. It has the property to be resistant to fire, water and moisture. The main elements in the glass fibers are silicon dioxide, calcium oxide, aluminum oxide, boron oxide, sodium/potassium oxide, magnesium oxide, iron oxide, titanium oxide, and fluoride, appearing in a decreasing order of concentration[(https://www.viasion.com/blog/what-is-fr4-material-properties-constituents-and-fabricate-steps/)]. The epoxy resin contains an epoxide group, made of two carbon and one oxygen atoms. The most common epoxy material is the DGEBA one, containing carbon hydrogen, chloride and oxygen[(https://resiners.com/blogs/resiners-guide/chemical-formula-of-epoxy?srsltid=AfmBOooBqMoahxKAUb9Ne2xNiQyvRCzmNBMTQ-1Pw-QS64I7LKNr25H2)]. Some derivatives exist, including one resistant for high temperature, using glass with higher fusion temperature [(substrate_types)]. The abreviation FR stands for Flame Retardant. 
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   * CEM-3: It has a similar composition as CEM-1, with a non-woven glass mat core instead of a paper one. It is more resistant and performant than CEM-1, cheaper but still less performant than FR-4. It is a cheaper alternative for double-sided PCBs [(substrate_types_allpcb>https://www.allpcb.com/allelectrohub/a-comparative-analysis-of-materials-used-for-rigid-pcb-design)].   * CEM-3: It has a similar composition as CEM-1, with a non-woven glass mat core instead of a paper one. It is more resistant and performant than CEM-1, cheaper but still less performant than FR-4. It is a cheaper alternative for double-sided PCBs [(substrate_types_allpcb>https://www.allpcb.com/allelectrohub/a-comparative-analysis-of-materials-used-for-rigid-pcb-design)].
   * Metal substrate: aluminum is often used as metal substrate, sometimes it is copper. It has the advantage to dissipate heat efficiently. It is mostly used for single or double-sided PCBs[(nextpcb)].   * Metal substrate: aluminum is often used as metal substrate, sometimes it is copper. It has the advantage to dissipate heat efficiently. It is mostly used for single or double-sided PCBs[(nextpcb)].
-  * Polytetrafluoroethylene (PTFE): this substrate is made of a plastic with very low resistance, which is adapted for high-frequency applications. The chemical composition is mainly fased on carbon and fluorine atoms. It is also very light and flame resistant [(substrate_types)]. It has also a proprietary alternative called Rogers®.+  * Polytetrafluoroethylene (PTFE): this substrate is made of a plastic with very low resistance, which is adapted for high-frequency applications. The chemical composition is mainly based on carbon and fluorine atoms. It is also very light and flame resistant [(substrate_types)]. It has also a proprietary alternative called Rogers®.
   * Ceramics: this substrate is employed for application requiring high temperature resistance, high thermal conductivity and need for high reliability. It is more expensive and fragile than a FR-4 substrate. It is often made of alumina, aluminum nitride or silicon carbide. [(https://www.allpcb.com/fr-FR/blog/pcb-knowledge/ceramic-pcbs.html)].    * Ceramics: this substrate is employed for application requiring high temperature resistance, high thermal conductivity and need for high reliability. It is more expensive and fragile than a FR-4 substrate. It is often made of alumina, aluminum nitride or silicon carbide. [(https://www.allpcb.com/fr-FR/blog/pcb-knowledge/ceramic-pcbs.html)]. 
  
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 Once the PCB layers are laminated and the copper traces printed, the metal needs to be protected by an additional layer of material. This layer can be composed of: Once the PCB layers are laminated and the copper traces printed, the metal needs to be protected by an additional layer of material. This layer can be composed of:
   * Electroless Nickel Immersion Gold (ENIG)[(https://www.protoexpress.com/kb/enig/)]: it consists in a film of nickel deposited on top of copper pads using electroless plating technique. The nickel is then protected from corrosion and oxidation by a thin layer of gold using immersion methods.   * Electroless Nickel Immersion Gold (ENIG)[(https://www.protoexpress.com/kb/enig/)]: it consists in a film of nickel deposited on top of copper pads using electroless plating technique. The nickel is then protected from corrosion and oxidation by a thin layer of gold using immersion methods.
-  * Elelectroless Nickel Electroless Palladium Immersion Gold (ENEPIG) [(https://www.protoexpress.com/kb/enepig-surface-finish/)]: similar to ENIG finish, with a thiner nickel layer and an additional layer of palladium deposited via electroless plating. It has the advantage to be compatible with almost any kind of PCB. +  * Electroless Nickel Electroless Palladium Immersion Gold (ENEPIG) [(https://www.protoexpress.com/kb/enepig-surface-finish/)]: similar to ENIG finish, with a thiner nickel layer and an additional layer of palladium deposited via electroless plating. It has the advantage to be compatible with almost any kind of PCB. 
   * Hot Air Solder Leveling (HASL)[(https://www.protoexpress.com/kb/hasl-surface-finish/)]: this technique is very affordable and offers a high solderability. It is not compatible with very thin-pitched PCBs. This finish layer is composed of a mixture of eutectic tin and lead. Its application is performed in three steps: the board is immersed in a bath of molten solder. The extra thickness of solder is removed thanks to hot air knives, that are heated above the solder melting temperature. Finally, the board is cleaned to remove all residues remaining after solder soliditication.   * Hot Air Solder Leveling (HASL)[(https://www.protoexpress.com/kb/hasl-surface-finish/)]: this technique is very affordable and offers a high solderability. It is not compatible with very thin-pitched PCBs. This finish layer is composed of a mixture of eutectic tin and lead. Its application is performed in three steps: the board is immersed in a bath of molten solder. The extra thickness of solder is removed thanks to hot air knives, that are heated above the solder melting temperature. Finally, the board is cleaned to remove all residues remaining after solder soliditication.
   * Organic Soderability Preservative (OSP)[(https://www.protoexpress.com/kb/osp-surface-finish/)], [(https://www.sharrettsplating.com/blog/osp-enig-difference/)] is affordable and features a very thin and flat finish. However, it doesn't resist to long storage. It is adapted for fine-pitch design, consumer electronics, and nickel-sensitive applications.  It is composed of azole-based organic compounds like benzotriazoles, imidazoles or benzimidazoles. It is applied by immersing the board into the organic solution, that will form a thin film in interaction with copper atoms.   * Organic Soderability Preservative (OSP)[(https://www.protoexpress.com/kb/osp-surface-finish/)], [(https://www.sharrettsplating.com/blog/osp-enig-difference/)] is affordable and features a very thin and flat finish. However, it doesn't resist to long storage. It is adapted for fine-pitch design, consumer electronics, and nickel-sensitive applications.  It is composed of azole-based organic compounds like benzotriazoles, imidazoles or benzimidazoles. It is applied by immersing the board into the organic solution, that will form a thin film in interaction with copper atoms.