Overview

General comment

Production covered

Fine-pitch ball grid array carrying several memory dies stacked vertically, each attached with die-attach film and wire-bonded on its own tier. Functional unit is one package STARTED: the reference flow is a single package entering assembly, and the activities listed run through completed assembly and final test of that package.

Modelling choices

By the count-once yield-ownership convention, the gross-up from packages started to good packages is carried by the consuming IC or component dataset, not here.

Technology: WB-FBGA-Stack, organic substrate
Geography: Global average data from equipment vendor specifications and industry literature

System boundary

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 1.7 Very good

Reliability

2.6

Completeness

1.8

Temporal

1.2

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: Equipment vendor specifications, academic papers, industry literature
Coverage status: Partial
Pedigree-scored source files: 13 — 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.

CF₄ production Process gasg · -49.2% / +69.5%

Derivation basis: No retrievable public document identified

No source is attached to this row.
Source citations: Not stated
Upstream REEL dataset: Carbon tetrafluoride (CF4)
Background dataset: Modelled by REEL; see the upstream dataset above.
Uncertainty: -49.2% / +69.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

SF₆ production Process gasg · -49% / +53.1%

Derivation basis: No retrievable public document identified

No source is attached to this row.
Source citations: Not stated
Upstream REEL dataset: Sulfur hexafluoride (SF6)
Background dataset: Modelled by REEL; see the upstream dataset above.
Uncertainty: -49% / +53.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Water supply (municipal) Waterm3 · -36.6% / +75.2%

Derivation basis: Calculated from process-water and ultrapure-water demand across all manufacturing operations, plus facility water allocated to each finished unit. The fresh intake shown is that demand less the share reused under the water-recycling scenario this dataset assumes, and wastewater follows the same balance.

No source is attached to this row.
Source citations: Not stated
Upstream REEL dataset: Water Supply (Municipal)
Background dataset: Modelled by REEL; see the upstream dataset above.
Notes: Net fresh-water intake, supplied as municipal water
Uncertainty: -36.6% / +75.2% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: m3

Electricity, Taiwan (TW) ElectricitykWh · -61% / +81.6%

Derivation basis: Calculated from equipment energy across all manufacturing operations. It also includes the assembly site's facility overhead: air handling and cleanroom conditioning, chilled water, compressed dry air, exhaust and dust collection, wastewater treatment and uninterruptible power.
REEL derivation: engineering estimate of per-package laser-marking energy from the marker system power rating and line throughput; no single published document reports this per-package value
REEL derivation: engineering estimate of per-package tape-and-reel energy from the equipment power rating and line throughput; no single published document reports this per-package value

The sources below come from the manufacturing operations behind this row.
Sources (inherited): Inherited, rolled up from the contributing process steps:

sst.semiconductor-digest.com (date not recorded). Semiconductor Digest - Package-on-package (PoP) with Through-mold Vias (2008). Trade press article.

directindustry.com (date not recorded). DirectIndustry - Kulicke & Soffa IConn (ProCu) PLUS wire bonder listing (1.5 kVA nominal / 2.6 kVA max).

c2mi.ca (date not recorded). C2MI - IConn ProCu Plus LA equipment listing.

electronicspecifier.com (date not recorded). electronicspecifier - ASMPT unveils latest wire bonder (Eagle AERO, up to 24 2-mm connections/s), 26 Sep 2022. Trade press article.

Guste, Marinas & Ong, Machines 12 (2024) 467, Table 3; Besi Datacon 2200 evo product page

Hu et al. (2019). Analysis of energy efficiency improvement of high-tech fabrication plants. International Journal of Low-Carbon Technologies. DOI: 10.1093/ijlct/ctz041.
Background data: ecoinvent 3.12
Background dataset: electricity, medium voltage
Uncertainty: -61% / +81.6% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kWh

Compressed air Process gasg · -27.4% / +37%

Derivation basis: Estimated from similar handling equipment

The sources below come from the manufacturing operations behind this row.
Source citations (specific to this process): Inherited, rolled up from the contributing process steps:

Hu et al. (2019). Analysis of energy efficiency improvement of high-tech fabrication plants. International Journal of Low-Carbon Technologies. DOI: 10.1093/ijlct/ctz041.
Background data: ecoinvent 3.12
Background dataset: compressed air, 700 kPa gauge
Uncertainty: -27.4% / +37% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Ar Process gasg · -60% / +100%

Derivation basis: No retrievable public document identified

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12
Background dataset: argon, liquid
Uncertainty: -60% / +100% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

O₂ Process gasg · -60% / +100%

Derivation basis: No retrievable public document identified

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12
Background dataset: oxygen, liquid
Uncertainty: -60% / +100% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

H₂ Process gasg · -25.7% / +50.2%

Derivation basis: No retrievable public document identified

The sources for this row are listed below.
Source citations: uwaterloo.ca (date not recorded). A. Pequegnat, J. Persic, M. Mayer, Y. Zhou, J. Hong, K. Ahn, "Effect of gas type and flow rate on Cu free air ball formation in thermosonic wire bonding", Microelectronics Reliability 51 (2011) 43-52, doi 10.1016/j.microrel.2010.02.023. PDF document.
Alfred Yeung, Ivy Sutiono, Jochen Milke (Heraeus Materials Technology), "Optimization of Free Air Ball Formation of Copper and Palladium Coated Copper Bonding Wires", Proceedings of IMAPS 2010, 43rd International Symposium on Microelectronics, pp. 000661 ff
Background data: ecoinvent 3.12
Background dataset: hydrogen, gaseous, low pressure
Uncertainty: -25.7% / +50.2% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

N₂ Process gasg · -22.3% / +34.3%

Source citations: uwaterloo.ca (date not recorded). A. Pequegnat, J. Persic, M. Mayer, Y. Zhou, J. Hong, K. Ahn, "Effect of gas type and flow rate on Cu free air ball formation in thermosonic wire bonding", Microelectronics Reliability 51 (2011) 43-52, doi 10.1016/j.microrel.2010.02.023. PDF document.
Alfred Yeung, Ivy Sutiono, Jochen Milke (Heraeus Materials Technology), "Optimization of Free Air Ball Formation of Copper and Palladium Coated Copper Bonding Wires", Proceedings of IMAPS 2010, 43rd International Symposium on Microelectronics, pp. 000661 ff
Background data: ecoinvent 3.12
Background dataset: nitrogen, liquid
Uncertainty: -22.3% / +34.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Copper sulfate pentahydrate (electroless) Process chemicalg · -16.7% / +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: ecoinvent 3.12
Background dataset: copper sulfate
Uncertainty: -16.7% / +33.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Copper anodes (pattern plating) Process chemicalg · -12.8% / +14.9%

Derivation basis: No retrievable public document identified (metric clarification; per-substrate mass derivation retained in notes)

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12
Background dataset: copper, cathode
Uncertainty: -12.8% / +14.9% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Formaldehyde solution Process chemicalg · ±25%

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: formaldehyde
Uncertainty: ±25% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Palladium chloride Process chemicalg · -45.5% / +36.4%

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: palladium
Notes: Proxy mapping uses 60% of the material mass.
Uncertainty: -45.5% / +36.4% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Nickel sulfate hexahydrate Process chemicalg · ±20%

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: nickel sulfate
Uncertainty: ±20% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Sodium hypophosphite Process chemicalg · ±25%

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: sodium phosphate
Uncertainty: ±25% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Gold potassium cyanide Process chemicalg · -15.1% / +13.2%

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: gold
Notes: Proxy mapping uses 68.4% of the material mass.
Uncertainty: -15.1% / +13.2% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Potassium permanganate Process chemicalg · -40% / +20%

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: potassium permanganate
Uncertainty: -40% / +20% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Dry film photoresist Process chemicalg · ±25%

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: ±25% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Stencil cleaner (IPA) Process chemicalg · -50% / +100%

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: isopropanol
Uncertainty: -50% / +100% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Flux (water soluble) Process chemicalg · -40% / +100%

Derivation basis: Flux type for FOWLP solder ball attach

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12
Background dataset: flux, for wave soldering
Uncertainty: -40% / +100% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

BT resin (4-layer HDI) Materialkg · ±15%

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.

The sources for this row are listed below.
Source citations (dataset-level): ASM Pacific Technology. IDEALmold Specifications
Disco Corporation. DFL7161 Laser Saw Specifications
IEEE ECTC 2018: Leading edge die stacking and wire bonding technologies for advanced 3D memory packages (doi:10.1109/ECTC.2018.00069)
Micron Y4BM LPDDR5/LPDDR5X datasheet (315b/441b FBGA, DDP/QDP/8DP)
Micron Y42M LPDDR5X datasheet (SDP/DDP/QDP/8DP)
Samsung LPDDR5X stacked die packages (K3KL series)
Background data: proxy-mapped
Background dataset: glass fibre reinforced plastic, polyester resin, hand lay-up
Uncertainty: ±15% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Die-attach film (DAF) for stacked dies Materialkg · -25% / +50%

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.

The sources for this row are listed below.
Source citations (dataset-level): ASM Pacific Technology. IDEALmold Specifications
Disco Corporation. DFL7161 Laser Saw Specifications
IEEE ECTC 2018: Leading edge die stacking and wire bonding technologies for advanced 3D memory packages (doi:10.1109/ECTC.2018.00069)
Micron Y4BM LPDDR5/LPDDR5X datasheet (315b/441b FBGA, DDP/QDP/8DP)
Micron Y42M LPDDR5X datasheet (SDP/DDP/QDP/8DP)
Samsung LPDDR5X stacked die packages (K3KL series)
Background data: ecoinvent 3.12
Background dataset: epoxy resin insulator, SiO2
Uncertainty: -25% / +50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Cu (20um diameter) - modern standard Materialkg · ±20%

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.

The sources for this row are listed below.
Source citations (dataset-level): ASM Pacific Technology. IDEALmold Specifications
Disco Corporation. DFL7161 Laser Saw Specifications
IEEE ECTC 2018: Leading edge die stacking and wire bonding technologies for advanced 3D memory packages (doi:10.1109/ECTC.2018.00069)
Micron Y4BM LPDDR5/LPDDR5X datasheet (315b/441b FBGA, DDP/QDP/8DP)
Micron Y42M LPDDR5X datasheet (SDP/DDP/QDP/8DP)
Samsung LPDDR5X stacked die packages (K3KL series)
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: kg

Epoxy Mold Compound (low-warpage for tall stacks) Materialkg · ±15%

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.

The sources for this row are listed below.
Source citations (dataset-level): ASM Pacific Technology. IDEALmold Specifications
Disco Corporation. DFL7161 Laser Saw Specifications
IEEE ECTC 2018: Leading edge die stacking and wire bonding technologies for advanced 3D memory packages (doi:10.1109/ECTC.2018.00069)
Micron Y4BM LPDDR5/LPDDR5X datasheet (315b/441b FBGA, DDP/QDP/8DP)
Micron Y42M LPDDR5X datasheet (SDP/DDP/QDP/8DP)
Samsung LPDDR5X stacked die packages (K3KL series)
Background data: ecoinvent 3.12
Background dataset: epoxy resin insulator, SiO2
Uncertainty: ±15% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

SAC305 Materialkg · ±20%

Derivation basis: Calculated from per-operation consumption, operation counts, and manufacturing yield.

The sources for this row are listed below.
Source citations (dataset-level): ASM Pacific Technology. IDEALmold Specifications
Disco Corporation. DFL7161 Laser Saw Specifications
IEEE ECTC 2018: Leading edge die stacking and wire bonding technologies for advanced 3D memory packages (doi:10.1109/ECTC.2018.00069)
Micron Y4BM LPDDR5/LPDDR5X datasheet (315b/441b FBGA, DDP/QDP/8DP)
Micron Y42M LPDDR5X datasheet (SDP/DDP/QDP/8DP)
Samsung LPDDR5X stacked die packages (K3KL series)
Background data: composite
Background dataset: Modelled as a composite of its constituent materials.
Uncertainty: ±20% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: kg

Outputs and waste

Wastewater Wastewaterm3 · -36.6% / +75.2%

Derivation basis: Calculated from the water balance: fresh-water input minus evaporation.

No source is attached to this row.
Source citations: Not stated
Background data: carried, no background dataset
Background dataset: No treatment route recorded for this output.
Uncertainty: -36.6% / +75.2% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: m3

Copper in wastewater-treatment sludge/recovery Solid wasteg · -49.3% / +52%

Source citations (dataset-level): mee.gov.cn (date not recorded). GB 39731-2020, Emission standard of water pollutants for the electronics industry (official MEE PDF) - Table 1 item 13 total copper 0.5 direct / 2.0 indirect mg/L; Table 2 benchmark effluent volumes per wafer / per m2 PCB / per package. Standard.
gazette.nat.gov.tw (date not recorded). Executive Yuan Gazette Vol. 030 No. 237, 2024-12-18 - amendment to Taiwan Effluent Standards; Attached Table 1 (wafer/semiconductor) and Table 5 (basic metal / surface treatment / electroplating / PCB) copper ladder 3.0 -> 2.0 -> 1.5 -> 1.0 mg/L by vintage and permitted flow. PDF document.
Source citations (dataset-level): Inherited from this dataset's own bibliography, not tied to this row:

mee.gov.cn (date not recorded). GB 39731-2020, Emission standard of water pollutants for the electronics industry (official MEE PDF) - Table 1 item 13 total copper 0.5 direct / 2.0 indirect mg/L; Table 2 benchmark effluent volumes per wafer / per m2 PCB / per package. Standard.

gazette.nat.gov.tw (date not recorded). Executive Yuan Gazette Vol. 030 No. 237, 2024-12-18 - amendment to Taiwan Effluent Standards; Attached Table 1 (wafer/semiconductor) and Table 5 (basic metal / surface treatment / electroplating / PCB) copper ladder 3.0 -> 2.0 -> 1.5 -> 1.0 mg/L by vintage and permitted flow. PDF document.
Background data: ecoinvent 3.12 treatment route
Background dataset: market for copper scrap, sorted, pressed
Uncertainty: -49.3% / +52% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Spent dry film resist Solid wasteg · ±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: treatment of waste plastic, mixture, municipal incineration
Uncertainty: ±25% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Manganate desmear sludge Solid wasteg · -40% / +35%

Source citations (dataset-level): rsc.org. Heterointerfacial adhesion failure mechanism of ultrahigh filler loading containing epoxy composite films for chip substrates.
tekhpolis.ru (date not recorded). S7439 PROCESS GUIDELINES. PDF document.
Source citations (dataset-level): Inherited from this dataset's own bibliography, not tied to this row:

rsc.org. Heterointerfacial adhesion failure mechanism of ultrahigh filler loading containing epoxy composite films for chip substrates.

tekhpolis.ru (date not recorded). S7439 PROCESS GUIDELINES. PDF document.
Background data: ecoinvent 3.12 treatment route
Background dataset: treatment of hazardous waste, underground deposit
Uncertainty: -40% / +35% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Solder mask develop sludge (unpolymerized resin) Solid wasteg · -34.8% / +30.4%

Derivation basis: No retrievable public document identified

No source is attached to this row.
Source citations: Not stated
Background data: ecoinvent 3.12 treatment route
Background dataset: treatment of waste plastic, mixture, municipal incineration
Uncertainty: -34.8% / +30.4% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Phosphorus in wastewater-treatment sludge Solid wasteg · ±47%

Derivation basis: Derived: elemental phosphorus balance, the phosphorus reaching treatment less the post-treatment residual

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: ±47% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit: g

Flux residue on stencil 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

Dicing slurry (Si/EMC/Cu particles) Solid wasteg

Derivation basis: No retrievable public document identified

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: No range defined.
Unit: g

Emissions to air

5 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 as an air release, from a mass balance on the process gases going in, with the destruction or removal efficiency of any point-of-use abatement applied.

No source is attached to this row.
Source citations: Not stated
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

HCHO Emission to airg

Derivation basis: Calculated as an air release, from a mass balance on the process gases going in, with the destruction or removal efficiency of any point-of-use abatement applied.

No source is attached to this row.
Source citations: Not stated
Compartment: Air (non-urban air or from high stacks)
CAS number: 50-00-0
ecoinvent 3.12 elementary flow: Formaldehyde
Uncertainty: A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit: g

VOCs (from epoxy cure) Emission to airg

Source citations: etd.gsfc.nasa.gov (date not recorded). NASA Goddard Space Flight Center, Engineering and Technology Directorate, "Outgassing Data for Selecting Spacecraft Materials" online database, complete CSV export (13,582 records; ASTM E595 total mass loss, collected volatile condensable material and water vapour regained by material, manufacturer and application).
etd.gsfc.nasa.gov (date not recorded). NASA Goddard Space Flight Center, Engineering and Technology Directorate, "Outgassing Database - User Guide" (ASTM E595 apparatus and conditions, TML / CVCM / WVR definitions, and the low-outgassing pass criteria).
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

Flux volatiles Emission to airg

Derivation basis: Calculated as an air release, from a mass balance on the process gases going in, with the destruction or removal efficiency of any point-of-use abatement applied.

No source is attached to this row.
Source citations: Not stated
Compartment: Air (non-urban air or from high stacks)
ecoinvent 3.12 elementary flow: NMVOC, non-methane volatile organic compounds
Uncertainty: No range defined.
Unit: g

Particulates (marking fume) Emission to airg

Derivation basis: Estimated from mold compound ablation

No source is attached to this row.
Source citations: Not stated
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

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

Cu2+ Emission to waterg

Source citations: mee.gov.cn (date not recorded). GB 39731-2020, Emission standard of water pollutants for the electronics industry (official MEE PDF) - Table 1 item 13 total copper 0.5 direct / 2.0 indirect mg/L; Table 2 benchmark effluent volumes per wafer / per m2 PCB / per package. Standard.
epa.gov (date not recorded). U.S. EPA Office of Water, "Preliminary Study of the Electrical and Electronic Components Point Source Category", EPA-821-R-22-005, DCN 11197 (2022) - Table 12 indirect Cu median 0.05 / mean 0.213 / max 5.64 / min 0.00015 mg/L (67 facilities, 1,309 results, 996 detects); Table 13 direct; Table 6 named-facility treatment trains; sec. 1.2.3.1 post-1983 process additions. Government report.
gazette.nat.gov.tw (date not recorded). Executive Yuan Gazette Vol. 030 No. 237, 2024-12-18 - amendment to Taiwan Effluent Standards; Attached Table 1 (wafer/semiconductor) and Table 5 (basic metal / surface treatment / electroplating / PCB) copper ladder 3.0 -> 2.0 -> 1.5 -> 1.0 mg/L by vintage and permitted flow. PDF document.
Compartment: Water (surface water)
Formula: Cu
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

Ni 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)
Formula: Ni2+
CAS number: 14701-22-5
ecoinvent 3.12 elementary flow: Nickel II
Uncertainty: A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit: g

CN- 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: 57-12-5
ecoinvent 3.12 elementary flow: Cyanide
Uncertainty: A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit: g

Phosphorus (from hypophosphite) Emission to waterg

Source citations: EU STM BREF 2006 §2.13.1.13 and §4.16.9.2; EPA E&EC Study Report 2022 Table 13
Compartment: Water (surface water)
Formula: P
CAS number: 7723-14-0
ecoinvent 3.12 elementary flow: Phosphorus
Uncertainty: A minimum-maximum range is defined for this flow. Bounds ship with the dataset on Circa.
Unit: g

Flows not quantified

No flows are recorded for this dataset without a quantity.

Limitations and unquantified flows (4)

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.

The die attach on this dataset is a film rather than a dispensed paste. It is booked at the per-die film mass this bill declares, once for each die in the stack, and the paste its die-attach process file would otherwise contribute is withheld so that the two are not counted together; no silver is booked. The declared per-die film mass is an engineering estimate: this dataset states a die size, but the film mass is not derived from that area and a bond line, and the dispense-loss allowance that belongs to dispensed paste is not applied to film.
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: Cu or Au wire bonding (all tiers) uses Copper wire (Cu); Ball attach reflow uses SAC305 solder balls.
Where the process record behind a step offers a choice of material, the modelled flow takes the one this dataset's own material list carries, and the entries it does not select are not added: Cu or Au wire bonding (all tiers) takes copper wire from that list, not Gold wire (Au); DAF die attach per stacked die takes die attach film from that list, not Die attach epoxy (Ag-filled conductive).
Some consumable pulls referenced by the modelled process steps did not resolve to an inventory row and are absent from this dataset. They are itemised in the dataset's own export audit.

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