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Overview

General comment

Enterprise hard disk drive with a helium-filled hermetic enclosure and glass recording substrates, assembled in a cleanroom.

Technology
Not stated
Geography
Global average data from equipment vendor specifications and industry literature

System boundary

System boundary - Enterprise HDD 3.5"System 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.Enterprise HDD 3.5"GATE INSub-component procurementENTERING FLOWSElectricityWaterMaterialsOtherSYSTEM BOUNDARYCOMPOSED OF OTHER REEL DATASETSExternal PCB (4-layer FR4)4-Layer FR4 PCB, ENIG finishHDD controller SoC (28 nmproxy)MCU, QFN, 28nmDRAM cache buffer (typical256-512 MB)DRAM IC 8Gb, FBGA, 1αSATA III or SAS 12 Gb/sedge connectorSATA SAS ConnectorREFERENCE PRODUCTEnterprise HDD 3.5"Final assemblyEMISSIONS 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 reason14FLOWSsystem 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 2.1 Good
Reliability
2.7
Completeness
2.5
Temporal
1.7
Geographic
2.0
Technological
1.9
How the score is calculated: Constituent datasets have more influence when they contribute a larger share of the modelled cradle-to-gate energy demand.

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

Sampling procedure
Component vendor specifications, academic papers, industry literature
Coverage status
Composed from linked REEL datasets
Pedigree-scored source files
77 — the source records behind this dataset's manufacturing operations. Each carries the five pedigree axes above; the composite DQI aggregates them.

Technosphere inputs

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

External PCB (4-layer FR4) REEL datasetm2
Derivation basis
  • Calculated by the manufacturing model. The linked REEL dataset carries the upstream life cycle sources.

No source is attached to this row.

Source citations
Not stated
Upstream REEL dataset
4-Layer FR4 PCB, ENIG finish
Background dataset
Modelled by REEL; see the upstream dataset above.
Notes
Adjusted for assembly yield.
Uncertainty
No range defined.
Unit
m2
HDD controller SoC (28 nm proxy) REEL datasetunit
Derivation basis
  • Calculated by the manufacturing model. The linked REEL dataset carries the upstream life cycle sources.

No source is attached to this row.

Source citations
Not stated
Upstream REEL dataset
MCU, QFN, 28nm
Background dataset
Modelled by REEL; see the upstream dataset above.
Notes
Adjusted for assembly yield.
Uncertainty
No range defined.
Unit
unit
DRAM cache buffer (typical 256-512 MB) REEL datasetunit
Derivation basis
  • Calculated by the manufacturing model. The linked REEL dataset carries the upstream life cycle sources.

No source is attached to this row.

Source citations
Not stated
Upstream REEL dataset
DRAM IC 8Gb, FBGA, 1α
Background dataset
Modelled by REEL; see the upstream dataset above.
Notes
Adjusted for assembly yield.
Uncertainty
No range defined.
Unit
unit
SATA III or SAS 12 Gb/s edge connector REEL datasetunit
Derivation basis
  • Calculated by the manufacturing model. The linked REEL dataset carries the upstream life cycle sources.

No source is attached to this row.

Source citations
Not stated
Upstream REEL dataset
SATA SAS Connector
Background dataset
Modelled by REEL; see the upstream dataset above.
Notes
Adjusted for assembly yield.
Uncertainty
No range defined.
Unit
unit
Aluminum Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
proxy-mapped
Background dataset
aluminium, cast alloy
Uncertainty
No range defined.
Unit
kg
Lubricant Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
ecoinvent 3.12
Background dataset
lubricating oil
Uncertainty
No range defined.
Unit
kg
Forming lubricant Materialkg · -50% / +150.1%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
ecoinvent 3.12
Background dataset
lubricating oil
Uncertainty
-50% / +150.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
NdFeB magnet alloy Materialkg · -18.6% / +21.9%
Derivation basis
Not stated
Source citations
Not stated
Background data
proxy-mapped
Background dataset
permanent magnet, for electric motor
Notes
Not stated
Proxy limitation
DECLARED PROXY on background composition. The ecoinvent permanent magnet dataset is built on an aluminium-smelting analogue, so the rare-earth mining, separation and reduction chain behind neodymium and dysprosium is effectively absent from it. The magnet MASS and the finished-form boundary are correct - no separate sintering step is added, by the count-once convention - but the rare-earth burden is understated by the background dataset. Accepted as a background-data limitation; re-modelling a rare-earth chain is out of scope.
Uncertainty
-18.6% / +21.9% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
Argon Materialkg
Derivation basis
  • REEL derivation: per-platter sputter argon consumption estimated from the chamber flow band typical of magnetron sputter tooling of this class and the platter residence time; argon consumption per platter is not published

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
argon, liquid
Uncertainty
No range defined.
Unit
kg
Copper Rod Materialkg · ±1%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
ecoinvent 3.12
Background dataset
copper, cathode
Uncertainty
±1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
Glass Materialkg · -11.8% / +17.6%
Derivation basis
  • REEL derivation: per-platter glass mass estimated from 3.5-inch platter geometry and the ten-platter stack mass of a disassembled high-capacity enterprise drive; the substrate is aluminosilicate glass for drives above about 20 TB, but no manufacturer publishes a per-platter substrate mass

No source is attached to this row.

Source citations
Not stated
Background data
proxy-mapped
Background dataset
flat glass, uncoated
Uncertainty
-11.8% / +17.6% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
Helium Materialkg · ±0.1%
Source citations
  • HE-490M - ATEQ Corp
Background data
ecoinvent 3.12
Background dataset
helium
Uncertainty
±0.1% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
Hydrogen Materialkg · -31.8% / +36.3%
Derivation basis
Not stated
Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
hydrogen, gaseous, low pressure
Notes
Not stated
Uncertainty
-31.8% / +36.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
Nickel Coating Materialkg
Derivation basis
  • REEL derivation: nickel input computed from the authored Ni-Cu-Ni coating thickness, the magnet surface area and nickel density; no retrievable public document was identified for the adopted value

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
nickel, class 1
Uncertainty
No range defined.
Unit
kg
Tin Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
ecoinvent 3.12
Background dataset
tin
Notes
From solder (96.5% tin)
Uncertainty
No range defined.
Unit
kg
Silver Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
ecoinvent 3.12
Background dataset
silver
Notes
From solder (3.0% silver)
Uncertainty
No range defined.
Unit
kg
Copper, cathode Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
ecoinvent 3.12
Background dataset
copper, cathode
Notes
From solder (0.5% copper)
Uncertainty
No range defined.
Unit
kg
Stainless Steel Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
ecoinvent 3.12
Background dataset
steel, chromium steel 18/8, hot rolled
Uncertainty
No range defined.
Unit
kg
Electricity, Global (GLO) ElectricitykWh · -13.2% / +13.5%
Derivation basis
  • Calculated from equipment energy across all manufacturing operations. This model includes no facility support, so the total is the manufacturing operations alone.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources below are this row's own, and this dataset's own bibliography. That bibliography is not tied to this row.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Source citations (dataset-level)
Inherited from this dataset's own bibliography, not tied to this row:
Background data
ecoinvent 3.12
Background dataset
electricity, medium voltage
Uncertainty
-13.2% / +13.5% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kWh
Process water WaterL · -31.7% / +36.3%
Derivation basis
  • Calculated from process-water and ultrapure-water demand across all manufacturing operations. This model includes no facility support, so the demand is the manufacturing operations alone. 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
Background data
ecoinvent 3.12
Background dataset
tap water
Notes
Aggregated water demand of this dataset's production stages.
Uncertainty
-31.7% / +36.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
L

Outputs and waste

Sheet-metal trimming scrap 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
market for iron scrap, sorted, pressed
Uncertainty
No range defined.
Unit
g
Spent forming lubricant 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
Rejected Platters 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
AlTiC kerf lapping waste 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 Photoresist Developer 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
CMP slurry waste 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
Machining Sludge 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, underground deposit
Uncertainty
No range defined.
Unit
g
Copper Scrap 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:
  • Niehoff Magazine EN. Double bow buncher, RBD line MSM 86 specific energy
  • Wire & Cable India Emagazine. Continuus-Properzi SAM machinery
  • HH-16 Multi wire Intermediate /fine wire drawing machine with annealing. Hooha HK
  • Niehoff 2017-2018 Cable Industry Guide. (MSM 86, R 502)
  • An Ultra-Fast Annealing Treatment by Electropulsing during Pure Copper Wire Drawing
  • Leading the way in sustainable lubrication. CONDAT Lubricants
Background data
ecoinvent 3.12 treatment route
Background dataset
market for copper scrap, sorted, pressed
Uncertainty
No range defined.
Unit
g
Spent Lubricant 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:
  • Niehoff Magazine EN. Double bow buncher, RBD line MSM 86 specific energy
  • Wire & Cable India Emagazine. Continuus-Properzi SAM machinery
  • HH-16 Multi wire Intermediate /fine wire drawing machine with annealing. Hooha HK
  • Niehoff 2017-2018 Cable Industry Guide. (MSM 86, R 502)
  • An Ultra-Fast Annealing Treatment by Electropulsing during Pure Copper Wire Drawing
  • Leading the way in sustainable lubrication. CONDAT Lubricants
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
Wire Scrap 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:
  • KZL Industrial Automation. "KZL-224 Automatic Stator Coil Winding Machine." (Details 13.6 kW power consumption and 0.5 Mpa air pressure)
  • KZL Industrial Automation. "KZL-228 & KZL-310 Stator Winding Machines." (10 kW and 1.5 kVA consumption profiles)
  • Riley et al. (1996). "Journal of Applied Physics 79:6342." (Empirical 1.72 kJ discharge on 4-pole NdFeB, 3380 A peak)
Background data
ecoinvent 3.12 treatment route
Background dataset
market for copper scrap, sorted, pressed
Uncertainty
No range defined.
Unit
g
Adhesive Waste 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:
  • KZL Industrial Automation. "KZL-224 Automatic Stator Coil Winding Machine." (Details 13.6 kW power consumption and 0.5 Mpa air pressure)
  • KZL Industrial Automation. "KZL-228 & KZL-310 Stator Winding Machines." (10 kW and 1.5 kVA consumption profiles)
  • Riley et al. (1996). "Journal of Applied Physics 79:6342." (Empirical 1.72 kJ discharge on 4-pole NdFeB, 3380 A peak)
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of inert waste, sanitary landfill
Uncertainty
No range defined.
Unit
g
Injection-molding runner and sprue scrap 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
Process solid waste, component assembly steps Solid wastekg
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
kg

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.

Particulate matter (AlTiC fines) 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
Particulate Matter, < 2.5 um
Uncertainty
No range defined.
Unit
g
Particulates (NdFeB dust) 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
Particulate Matter, < 2.5 um
Uncertainty
No range defined.
Unit
g

Emissions to water

No emissions to water are recorded at this level.

Flows not quantified

14 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.

Cut off - below the significance threshold (1)

Plastic Compound Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
cut off
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
A generic plastic housing or insulation material, recorded in this inventory. Where its mass is significant it is tracked as a named plastic at component level, so no upstream production dataset is attached to this catch-all entry.
Uncertainty
No range defined.
Unit
kg

Not modelled (13)

AlTiC wafer substrate Materialkg · ±25%
Derivation basis
  • REEL calculation from authored geometry and density; an archived university report supports AlTiC identity only
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
±25% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
CMP slurry Materialkg
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
No range defined.
Unit
kg
PFPE lubricant Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
No range defined.
Unit
kg
Tooling wear Materialkg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
No range defined.
Unit
kg
Insulation Paper Materialkg · -33.3% / +66.7%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
-33.3% / +66.7% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
Lead Wire Materialkg · -25% / +50%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
-25% / +50% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
Magnet Adhesive Materialkg · -40% / +60%
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • REEL derivation: engineering estimate of hard-disk-drive component mass and process inventory from vendor product data and teardown geometry; no single published inventory covers this device

The sources for this row are listed below.

Source citations (dataset-level)
  • Seagate Exos X22 sustainability report - Tier 1 retrospective LCA validation anchor (28.7 kg CO2e)
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
-40% / +60% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kg
Photoresist Developer Materialkg
Derivation basis
Not stated
Source citations
Not stated
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
No range defined.
Unit
kg
Plasma Gases Materialkg
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
No range defined.
Unit
kg
Sputter Target Metals Materialkg
Derivation basis
  • REEL derivation: sputter target consumption estimated from the magnetic stack thickness, the two-sided platter area and a 10-40 percent target utilisation band; no retrievable public document was identified for the adopted value

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
The quantified material is retained, but its authored name does not identify a sufficiently specific background dataset or defensible proxy; background modeling remains an explicit gap.
Uncertainty
No range defined.
Unit
kg
AlTiC wafer material Materialkg
Derivation basis
Not stated
Source citations
Not stated
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
AlTiC wafer material is declared below the model's current resolution for the read/write head sliders; the evaluated cutoff is recorded but not quantified in this dataset.
Uncertainty
No range defined.
Unit
kg
PFPE platter lubricant Process chemicalkg
Derivation basis
Not stated
Source citations
Not stated
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
PFPE platter lubricant is declared below the model's current resolution and has no supported upstream link; the evaluated cutoff is recorded but not quantified in this dataset.
Uncertainty
No range defined.
Unit
kg
Sputter target metals Materialkg
Derivation basis
Not stated
Source citations
Not stated
Background data
not modelled
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
The platter sputter-target metals are declared below the model's current multi-component resolution; the evaluated cutoff is recorded but not quantified in this dataset.
Uncertainty
No range defined.
Unit
kg

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 flows are named in this inventory but ship without a quantity, so their burden is not carried anywhere in the dataset: AlTiC wafer material; PFPE platter lubricant; Process solid waste, component assembly steps; Sputter target metals. Each row states its own reason on the row itself.

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