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Overview

General comment

Production covered

10-layer Substrate-Like PCB fabrication. The system boundary runs from laminate preparation and inner-layer imaging through lamination, drilling and via formation, plating and etching, solder mask, surface finishing, and electrical test.

The selected HASL finish means lowest cost, good solderability, rough surface (~20% market).

Modelling choices

Process inputs are normalized from the authored panel-area basis to one square metre of good PCB; no separate board-nesting utilization factor is applied. The 82.5% first-pass yield gross-ups all panel-process inputs to the functional unit.

This PCB family has no operational scenario because surface finish is its only configurable production choice, and no fab gas-recovery scenario applies to a panel process. This dataset is modelled with no water reuse. No reclaim rate is published for this kind of plant, so the water shown is the full fresh intake and no recycling credit has been deducted from it.

Technology
Substrate-Like PCB, 10-layer
Geography
Global average data from PCB manufacturer data, IPC standards, and industry literature

System boundary

System boundary - 10-Layer SLP PCB, HASL finishSystem boundary figure: identity, gate in, entering flows, the dashed system boundary and the unit processes inside it, the reference product, emissions and waste, and below it the flows that are recorded but not quantified. No inventory quantities.10-Layer SLP PCB, HASL finishGATE INCopper-clad laminate panels and chemicalsENTERING FLOWSElectricityWaterProcess chemicalsMaterialsSYSTEM BOUNDARYMODELLED UNIT PROCESSES, BY CLASSPCB fabricationPCB laminationPCB laser drillingPCB dry film laminationPCB DI lithographyPCB MSAP electroless CuPCB MSAP pattern platingPCB solder maskPCB ENIGPCB oxide treatmentPCB desmearPCB silkscreenInterconnectPCB via fill platingEtchPCB flash etchTestPCB electrical testREFERENCE PRODUCT10-Layer SLP PCB, HASL finishFinished PCB panel with surface finishand solder maskEMISSIONS AND WASTEEmissions to airEmissions to waterWaste routesRECORDED BUT NOT QUANTIFIEDIn scope, left out of the quantified inventoryCut off below the significance threshold, or with no background dataset available - each is listed with its reason5FLOWSsystem boundaryreference flowentering flowemission / waste

The figure groups this dataset's unit processes by class. It is not a count of manufacturing steps — each process runs over as many passes as the flow requires, and those pass counts ship with the dataset.

Download this figure (SVG)

Data quality and references

Composite DQI 1.9 Very good
Reliability
2.8
Completeness
2.4
Temporal
1.6
Geographic
2.0
Technological
1.2

Pedigree scores follow the ecoinvent data-quality matrix: 1 is the best attainable, 5 the weakest. The composite is their aggregate.

Sampling procedure
PCB manufacturer specifications, IPC standards, academic papers
Coverage status
Partial
Pedigree-scored source files
15 — the source records behind this dataset's manufacturing operations. Each carries the five pedigree axes above; the composite DQI aggregates them.

Technosphere inputs

25 flows. Quantities are not published; they ship with the dataset on Circa.

PCB release film Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • This flow is a consumable of the manufacturing operation. The model reads it from the operation's own inventory rather than from the product's bill of materials.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
polyethylene terephthalate, granulate, amorphous
Uncertainty
No range defined.
Unit
kg
Kraft press paper Materialkg · -57.1% / +90.5%
Derivation basis
  • This flow is a consumable of the manufacturing operation. The model reads it from the operation's own inventory rather than from the product's bill of materials.

The sources for this row are listed below.

Source citations
Background data
ecoinvent 3.12
Background dataset
kraft paper
Uncertainty
-57.1% / +90.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
Electricity, China (CN) ElectricitykWh · -21.8% / +27.5%
Derivation basis
  • Calculated from equipment energy across all manufacturing operations, plus the facility support a board shop runs: cooling for the lamination press and the plating baths, and treatment of the water the shop discharges.

The sources below come from the manufacturing operations behind this row.

Sources (inherited)
Inherited, rolled up from the contributing process steps:
Background data
ecoinvent 3.12
Background dataset
electricity, medium voltage
Uncertainty
-21.8% / +27.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kWh
Fresh water WaterL · -29.7% / +42.9%
Derivation basis
  • Calculated from process-water demand across all manufacturing operations, plus cooling-tower makeup for the lamination press and the plating baths.

The sources below come from the manufacturing operations behind this row.

Sources (inherited)
Inherited, rolled up from the contributing process steps:
  • ResearchGate, Water use in PCB manufacturing
  • Envirowise, Water use in PCB manufacturing
  • Patent CN102286761B, Acid Copper Additives
  • Patent US5151170A, Brightener Consumption
  • SysPCB, Inner Layer Process
  • NMFRC, Electroless Nickel Stoichiometry
Background data
ecoinvent 3.12
Background dataset
tap water
Notes
Process and cleaning water
Uncertainty
-29.7% / +42.9% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
L
Copper sulfate pentahydrate Process chemicalg · -33.3% / +38.8%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
copper sulfate
Uncertainty
-33.3% / +38.8% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Sulfuric acid Process chemicalg · -41.2% / +85.3%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
sulfuric acid
Uncertainty
-41.2% / +85.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Hydrochloric acid (chloride source) Process chemicalg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
hydrochloric acid, without water, in 30% solution state
Uncertainty
No range defined.
Unit
g
Dry Film Resist Process chemicalg · -7.4% / +11.1%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
proxy-mapped
Background dataset
methyl methacrylate
Uncertainty
-7.4% / +11.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Sodium carbonate developer Process chemicalg · -33.3% / +50%
Source citations
Background data
ecoinvent 3.12
Background dataset
soda ash, dense
Uncertainty
-33.3% / +50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Sodium hydroxide stripper Process chemicalg · -50% / +66.7%
Source citations
Background data
ecoinvent 3.12
Background dataset
sodium hydroxide, without water, in 50% solution state
Uncertainty
-50% / +66.7% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Formaldehyde Process chemicalg · -49.6% / +100%
Source citations
Background data
ecoinvent 3.12
Background dataset
formaldehyde
Uncertainty
-49.6% / +100% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
EDTA chelator Process chemicalg
Source citations
Background data
ecoinvent 3.12
Background dataset
EDTA, ethylenediaminetetraacetic acid
Uncertainty
No range defined.
Unit
g
Sodium hydroxide (pH control) Process chemicalg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
sodium hydroxide, without water, in 50% solution state
Uncertainty
No range defined.
Unit
g
Hydrogen peroxide Process chemicalg · -37.5% / +87.5%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
hydrogen peroxide, without water, in 50% solution state
Uncertainty
-37.5% / +87.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Solder mask solvent carrier Process chemicalg · -62.9% / +20%
Background data
proxy-mapped
Background dataset
chemical, organic, unspecified
Uncertainty
-62.9% / +20% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Sodium hydroxide Process chemicalg · -34.8% / +41.3%
Source citations
  • ResearchGate, Water use in PCB manufacturing
  • Envirowise, Water use in PCB manufacturing
  • Patent CN102286761B, Acid Copper Additives
  • Patent US5151170A, Brightener Consumption
  • SysPCB, Inner Layer Process
  • NMFRC, Electroless Nickel Stoichiometry
Background data
ecoinvent 3.12
Background dataset
sodium hydroxide, without water, in 50% solution state
Uncertainty
-34.8% / +41.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Trisodium phosphate Process chemicalg · -40% / +60%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
trisodium phosphate
Uncertainty
-40% / +60% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Potassium permanganate Process chemicalg · -81.3% / +34.1%
Source citations
Background data
ecoinvent 3.12
Background dataset
potassium permanganate
Uncertainty
-81.3% / +34.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Neutralizer (sulfuric acid or HCl) Process chemicalg · -20% / +50%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
sulfuric acid
Uncertainty
-20% / +50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
SAC305 solder alloy Process chemicalg · ±33.3%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
composite
Background dataset
Modelled as a composite of its constituent materials.
Uncertainty
±33.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Liquid flux Process chemicalmL · -40% / +60%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
flux, for wave soldering
Uncertainty
-40% / +60% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
mL
ABF build-up film Materialg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
proxy-mapped
Background dataset
epoxy resin insulator, SiO2
Uncertainty
No range defined.
Unit
g
Copper Foil Materialg · -10% / +0%
Background data
proxy-mapped
Background dataset
copper, cathode
Uncertainty
-10% / +0% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Copper Plating Materialg · ±20%
Background data
ecoinvent 3.12
Background dataset
copper, cathode
Uncertainty
±20% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Solder Mask Materialg · -22.9% / +27.1%
Source citations
Background data
proxy-mapped
Background dataset
epoxy resin, liquid
Notes
Purchased input grossed to fund the authored process loss booked as Solder mask solids (developed) (mass-closure funding; the retained mass is the product-side figure).
Uncertainty
-22.9% / +27.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g

Outputs and waste

Wastewater Wastewaterm3 · -29.7% / +42.9%
Derivation basis
  • Calculated from the water balance: fresh-water input minus evaporation.

The sources below come from the manufacturing operations behind this row.

Sources (inherited)
Inherited, rolled up from the contributing process steps:
  • ResearchGate, Water use in PCB manufacturing
  • Envirowise, Water use in PCB manufacturing
  • Patent CN102286761B, Acid Copper Additives
  • Patent US5151170A, Brightener Consumption
  • SysPCB, Inner Layer Process
  • NMFRC, Electroless Nickel Stoichiometry
Background data
carried, no background dataset
Background dataset
No treatment route recorded for this output.
Uncertainty
-29.7% / +42.9% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
m3
Resin bleed-out Solid wasteg · -80% / +300%
Source citations
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of inert waste, sanitary landfill
Uncertainty
-80% / +300% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Kraft press paper Solid wasteg · -57.1% / +90.5%
Source citations
Background data
ecoinvent 3.12 treatment route
Background dataset
market for waste paperboard, sorted
Uncertainty
-57.1% / +90.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Ablated dielectric debris Solid wasteg
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of inert waste, sanitary landfill
Uncertainty
No range defined.
Unit
g
Copper recovered before outfall discharge Solid wasteg · -100% / +177.8%
Source citations
Background data
ecoinvent 3.12 treatment route
Background dataset
market for copper scrap, sorted, pressed
Uncertainty
-100% / +177.8% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Anode bag sludge (phosphorus + organic adsorbates) Solid wasteg
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below are this dataset's own bibliography. They are not tied to this row.

Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, underground deposit
Uncertainty
No range defined.
Unit
g
DFR cover film (peeled before exposure) Solid wasteg
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of inert waste, sanitary landfill
Uncertainty
No range defined.
Unit
g
Spent / lock-in DFR rejects Solid wasteg
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, hazardous waste incineration, with energy recovery
Uncertainty
No range defined.
Unit
g
Develop sludge (filtered DFR particulate) Solid wasteg
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below are this dataset's own bibliography. They are not tied to this row.

Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, hazardous waste incineration, with energy recovery
Uncertainty
No range defined.
Unit
g
Stripped DFR (post-plate) Solid wasteg
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below come from the manufacturing operations behind this row.

Sources (inherited)
Inherited, rolled up from the contributing process steps:
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, hazardous waste incineration, with energy recovery
Uncertainty
No range defined.
Unit
g
Spent bath bail-out (sludge + Cu precipitate) Solid wasteg
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below are this dataset's own bibliography. They are not tied to this row.

Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
market for copper scrap, sorted, pressed
Uncertainty
No range defined.
Unit
g
Spent etchant copper (post-electrowinning) Solid wasteg
Source citations
Background data
ecoinvent 3.12 treatment route
Background dataset
market for copper scrap, sorted, pressed
Uncertainty
No range defined.
Unit
g
Solder mask solids (developed) Solid wasteg · ±25%
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of waste plastic, mixture, municipal incineration
Uncertainty
±25% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Spent oxide solution sludge Solid wasteg · -89.8% / +614.3%
Source citations (dataset-level)
Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, underground deposit
Uncertainty
-89.8% / +614.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Epoxy smear residue Solid wasteg · -73.9% / +195.4%
Source citations
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of inert waste, sanitary landfill
Uncertainty
-73.9% / +195.4% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Manganese sludge (filter cake) Solid wasteg · -86% / +101.2%
Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, underground deposit
Uncertainty
-86% / +101.2% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Routing dust (FR-4 particles) Solid wasteg · -63.5% / +62.2%
Source citations
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of inert waste, sanitary landfill
Uncertainty
-63.5% / +62.2% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Copper Sludge Solid wasteg · -33.3% / +25%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
market for metalliferous hydroxide sludge
Uncertainty
-33.3% / +25% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Neutralization Sludge Solid wasteg · ±50%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, underground deposit
Uncertainty
±50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Solder dross Solid wasteg · -37.5% / +50%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below come from the manufacturing operations behind this row.

Sources (inherited)
Inherited, rolled up from the contributing process steps:
  • AIM Solder white paper - Understanding Solder Dross; Indium Corporation reclaim data
Background data
ecoinvent 3.12 treatment route
Background dataset
market for waste tin sheet
Uncertainty
-37.5% / +50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Spent flux residue Solid wasteg · -33.3% / +66.7%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, hazardous waste incineration, with energy recovery
Uncertainty
-33.3% / +66.7% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Scrapped material (line yield) Solid wasteg · -3.1% / +0.8%
Derivation basis
  • Calculated from the mass balance of spent materials and consumables, with treatment selected from the waste classification.

The sources below are this dataset's own bibliography. They are not tied to this row.

Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12 treatment route
Background dataset
market for copper scrap, sorted, pressed
Notes
Calculated reject material after accounting for a manufacturing yield of 82.5%.
Uncertainty
-3.1% / +0.8% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g

Emissions to air

2 elementary flows released to air by this dataset's own operations. Quantities are not published; they ship with the dataset on Circa.

Volatile organic compounds (VOCs) Emission to airg
Derivation basis
  • Calculated from flux solids and VOC content; MIT EHS-0167; NIOSH NPG

The sources for this row are listed below.

Compartment
Air (non-urban air or from high stacks)
ecoinvent 3.12 elementary flow
NMVOC, non-methane volatile organic compounds
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
Particulates Emission to airg
Source citations
  • AIM Solder dross study; NIOSH soldering fume data
Compartment
Air (non-urban air or from high stacks)
ecoinvent 3.12 elementary flow
Particulate Matter, < 2.5 um
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g

Emissions to water

6 elementary flows released to water by this dataset's own operations. Quantities are not published; they ship with the dataset on Circa.

Cu Emission to waterg
Source citations
Compartment
Water (surface water)
CAS number
7440-50-8
ecoinvent 3.12 elementary flow
Copper ion
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
Sulfate Emission to waterg
Compartment
Water (surface water)
Formula
SO42-
CAS number
14808-79-8
ecoinvent 3.12 elementary flow
Sulfate
Notes
Aggregated from 3 contributing steps: H2SO4 dissociates in water → 2H⁺ + SO4²⁻ + K2SO4 → 2K⁺ + SO4²⁻ (ionic dissociation)
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
Mixed organics (COD) Emission to waterg
Derivation basis
  • Calculated as a release to water, from a contaminant mass balance on the process chemistry.

No source is attached to this row.

Source citations
Not stated
Compartment
Water (surface water)
ecoinvent 3.12 elementary flow
COD, Chemical Oxygen Demand
Uncertainty
No range defined.
Unit
g
H2O2 Emission to waterg
Derivation basis
  • Calculated as a release to water, from a contaminant mass balance on the process chemistry.

No source is attached to this row.

Source citations
Not stated
Compartment
Water (surface water)
CAS number
7722-84-1
ecoinvent 3.12 elementary flow
Hydrogen peroxide
Uncertainty
No range defined.
Unit
g
Mn2+ Emission to waterg
Compartment
Water (surface water)
CAS number
16397-91-4
ecoinvent 3.12 elementary flow
Manganese II
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g
Potassium Emission to waterg
Compartment
Water (surface water)
Formula
K+
CAS number
24203-36-9
ecoinvent 3.12 elementary flow
Potassium I
Notes
K2SO4 → 2K⁺ + SO4²⁻ (ionic dissociation)
Uncertainty
A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit
g

Flows not quantified

5 flows are recorded for this dataset but carry no quantity — cut off below the significance threshold, or with no background dataset available. They remain inside the declared system boundary; each is listed with its reason.

Not modelled (5)

Suppressor (PEG) Process chemicalg · -40% / +60%
Source citations
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
Proprietary plating or printing additive consumed in trace quantity, recorded in this inventory. Formulations vary by supplier and no representative public production dataset exists, so the upstream burden is left unlinked rather than approximated with an unrepresentative proxy.
Uncertainty
-40% / +60% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Accelerator (SPS) Process chemicalg · -33.3% / +66.7%
Source citations
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
Proprietary plating or printing additive consumed in trace quantity, recorded in this inventory. Formulations vary by supplier and no representative public production dataset exists, so the upstream burden is left unlinked rather than approximated with an unrepresentative proxy.
Uncertainty
-33.3% / +66.7% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Leveler (Janus Green B class) Process chemicalg · ±50%
Source citations
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
Proprietary plating or printing additive consumed in trace quantity, recorded in this inventory. Formulations vary by supplier and no representative public production dataset exists, so the upstream burden is left unlinked rather than approximated with an unrepresentative proxy.
Uncertainty
±50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Sodium chlorite Process chemicalg · -16.7% / +11.1%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
Consumption is recorded in this inventory. No production dataset for sodium chlorite exists in the public background database used for linkage. Chlorate, chloride, and hypochlorite chemistries are available, but not chlorite, so the upstream burden is left unlinked rather than approximated with a chemically different proxy.
Uncertainty
-16.7% / +11.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
g
Ultra Thin Core Materialg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.

No source is attached to this row.

Source citations
Not stated
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
This specialized layer construction is recorded in this inventory. No direct background production dataset exists for it, so the upstream burden is left unlinked rather than approximated with an unrepresentative laminate proxy.
Uncertainty
No range defined.
Unit
g

Limitations and unquantified flows (1)

Limits this dataset declares about itself: first any limit stated in its own description, then any limit it declares flow by flow, grouped by channel. Each entry below is the model's own disclosure.

  • These materials are used at a step of the modelled flow and are also carried by this dataset's own material list. Each is counted once, on that list, and the step does not book it again: Via fill plating (bottom-up superfill) uses Copper anode (phosphorized soluble).

The flows above are this dataset's own records. What follows are the scope rules set once for the whole database in the methodology report, repeated here so every dataset page carries them.

Database-wide boundary policy — applies to every REEL dataset

These boundaries are set once for the whole database, in Chapter 2 of the methodology report, and apply to this dataset wherever they are relevant to it. The excluded flows listed above are specific to this dataset.

Use phase
Product operation is outside the cradle-to-gate scope.
End-of-life treatment
Recycling and disposal are outside the cradle-to-gate scope.
Distribution and retail
The gate is a finished component ready for integration into a higher-level assembly.
Inbound transport of raw materials
Transport of purchased raw materials to the manufacturing facility is already inside the upstream "market for" datasets that users link to a background database, so it is not modelled a second time here. This does not cover freight between REEL production stages, which is modelled where a dataset authors it.
Returnable shipping containers
Where freight between production stages is modelled, the mass moved is the product itself. The shipping container (FOSB, SEMI M31) is returnable capital equipment whose per-trip share is unsourced, so its tare is excluded from the transport effort.
Photomask fabrication
A mask set's embodied burden is amortised across a high-volume production run and is not attributed per wafer. Users assessing low-volume production should add mask fabrication separately; the methodology report gives the basis for the exclusion.
Employee transport, administration and R&D overhead
Employee transportation, facility administration and R&D/pilot-production overhead are outside scope.
Capital goods
Manufacturing equipment, cleanroom construction and facility infrastructure are excluded, on the grounds of absent public data on equipment embodied energy, uncertainty in equipment lifetime and allocation, common practice in electronics LCA, and a focus on the operational inventory. Future versions may include capital goods when sufficient public data becomes available.
Precious metal recovery credits
Scrap recovery credits for precious metals are excluded pending data availability.
Wafer reclaim
Test wafers and scrap are outside the system boundary.

Inside the boundary, linked rather than modelled

Silicon ingot growth and wafer slicing
Inside the cradle-to-gate scope, but treated as upstream material inputs linked to background databases rather than modelled as REEL processes.
Freight between production stages
Where a dataset's product moves between REEL production stages - wafer fabrication to the packaging site, for example - that leg is authored as a transport service and linked to an ecoinvent freight activity. It is measured as a transport effort in tonne-kilometres, not as a mass. Route distances are authored per route class with a stated band; a lower bound of zero is a modelling statement that the two sites can be co-located, not a missing value.

Cut-off criteria

A flow is excluded from a process inventory when it contributes less than 1 % of the total mass of inputs to that unit process, or less than 1 % of its total energy input. The denominator is total process inputs, not product mass. That distinction matters in semiconductor manufacturing, where the input mass of water, chemicals and gases greatly exceeds the product mass, so the threshold removes only genuinely minor flows.

Included regardless of the cut-off

  • Perfluorocarbons (CF4, C2F6, SF6, NF3) - high GWP, EPA regulated
  • Heavy metals (Pb, Cd, Hg, Cr(VI)) - RoHS regulated, high toxicity
  • Volatile organics (photoresist solvents, PGMEA) - air quality
  • Precious metals (Au, Ag, Pd, Pt) - high embodied impacts
  • Ozone-depleting substances (legacy CFCs, HCFCs) - Montreal Protocol