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Overview

General comment

Backside-illuminated (BSI) CMOS image sensor for smartphone cameras. 12 megapixel resolution with 1.4µm pixel pitch. Stacked design with pixel array wafer bonded to logic wafer for high-speed readout. Advanced color filter array and microlens array for sensitivity.

Technology
Standard manufacturing process
Geography
Global average data from equipment vendor specifications and industry literature

System boundary

System boundary - CIS Image SensorSystem 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.CIS Image SensorGATE INRaw materials and sub-componentsENTERING FLOWSElectricityWaterProcess gasesProcess chemicalsFreight transportOtherSYSTEM BOUNDARYCOMPOSED OF OTHER REEL DATASETSPixel WaferCIS BSI 300mm wafer, 300mm, JapanLogic Wafer28nm Planar HKMG wafer, 300mm,moderate scenarioREFERENCE PRODUCTCIS Image SensorAssembled and tested componentEMISSIONS 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 reason3FLOWSsystem 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 2.2 Good
Reliability
2.9
Completeness
2.1
Temporal
2.0
Geographic
2.0
Technological
2.4
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
39 — the source records behind this dataset's manufacturing operations. Each carries the five pedigree axes above; the composite DQI aggregates them.

Technosphere inputs

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

Pixel Wafer REEL datasetwafer
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
CIS BSI 300mm wafer, 300mm, Japan
Background dataset
Modelled by REEL; see the upstream dataset above.
Notes
Wafer demand calculated from die count, rectangular wafer packing, die yield and assembly yield. Wafer manufacturing yield is already included upstream.
Uncertainty
No range defined.
Unit
wafer
Logic Wafer REEL datasetwafer
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
Background dataset
Modelled by REEL; see the upstream dataset above.
Notes
Wafer demand calculated from die count, rectangular wafer packing, die yield and assembly yield. Wafer manufacturing yield is already included upstream.
Uncertainty
No range defined.
Unit
wafer
Wafer transport, JP fab to packaging site - Air (short haul) Freight transporttkm · -47.4% / +80%
Derivation basis
  • Specified for this manufacturing operation and scaled to the dataset's functional unit.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
transport, freight, aircraft, dedicated freight, short haul
Notes
Freight for the part-finished product moving between REEL-modelled sites: the wafer fraction this dataset consumes, travelling from fab to packaging site, cross-border. Shipped mass is that wafer fraction times the wafer mass implied by its declared diameter, times a shipping-packaging factor covering the returnable front-opening shipping box and its secondary carton; the packaging production burden is excluded as returnable, while its mass is carried because freight scales with what is actually shipped. Air freight is allocated on chargeable weight rather than actual shipped mass. The authored band holds the fixed route distance: its lower endpoint uses actual shipped mass, its central uses chargeable-weight allocation, and its upper endpoint adds the separate reusable-carrier return service, not aircraft backhaul.
Uncertainty
-47.4% / +80% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
tkm — tonne-kilometres, a transport effort rather than a mass
Wafer transport, TW fab to packaging site - Air (medium haul) Freight transporttkm · -100% / +521.8%
Derivation basis
  • Specified for this manufacturing operation and scaled to the dataset's functional unit.

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
transport, freight, aircraft, dedicated freight, medium haul
Notes
Freight for the part-finished product moving between REEL-modelled sites: the wafer fraction this dataset consumes, travelling from mature-node foundry fab to offshore commodity OSAT share. Shipped mass is that wafer fraction times the wafer mass implied by its declared diameter, times a shipping-packaging factor covering the returnable front-opening shipping box and its secondary carton; the packaging production burden is excluded as returnable, while its mass is carried because freight scales with what is actually shipped. Air freight is allocated on chargeable weight rather than actual shipped mass. The authored band carries marginal mature-lane mode-share uncertainty: the lower endpoint allows this mode's share to be zero and the upper assigns all shipment mass to its own longest-lane air endpoint with chargeable-weight allocation and reusable-carrier return, not aircraft backhaul. Road and air endpoints are anti-correlated and not additive.
Uncertainty
-100% / +521.8% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
tkm — tonne-kilometres, a transport effort rather than a mass
Wafer transport, TW fab to packaging site - Road Freight transporttkm · -100% / +788.9%
Derivation basis
  • Specified for this manufacturing operation and scaled to the dataset's functional unit.

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

Sources (inherited)
Inherited, rolled up from the contributing process steps:
  • Focus Taiwan report, 2026-04-10: ASE Kaohsiung operations
  • TrendForce news report, 2024-08-06: SPIL chip-on-wafer order
Background data
ecoinvent 3.12
Background dataset
transport, freight, lorry, unspecified
Notes
Freight for the part-finished product moving between REEL-modelled sites: the wafer fraction this dataset consumes, travelling from mature-node foundry fab to domestic commodity OSAT share. Shipped mass is that wafer fraction times the wafer mass implied by its declared diameter, times a shipping-packaging factor covering the returnable front-opening shipping box and its secondary carton; the packaging production burden is excluded as returnable, while its mass is carried because freight scales with what is actually shipped. Road freight is allocated on actual shipped mass, and the mapped road market already includes carrier empty returns; the central therefore has no return uplift. The authored band carries marginal mature-lane mode-share uncertainty: the lower endpoint allows this mode's share to be zero and the upper assigns all shipment mass to its own physically reachable intra-island road endpoint. Road and air endpoints are anti-correlated and not additive.
Uncertainty
-100% / +788.9% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
tkm — tonne-kilometres, a transport effort rather than a mass
Electricity, Taiwan (TW) ElectricitykWh · -15.6% / +19.3%
Derivation basis
  • Calculated from equipment energy across all manufacturing operations. This model includes no facility support, so the total is the manufacturing operations alone.

No source is attached to this row.

Source citations
Not stated
Background data
ecoinvent 3.12
Background dataset
electricity, high voltage
Notes
Energy demand from hybrid bonding and CSP packaging, adjusted for assembly yield.
Uncertainty
-15.6% / +19.3% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
kWh
Process water WaterL · -22.8% / +24.2%
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
-22.8% / +24.2% around the published quantity. The bounds themselves ship with the dataset on Circa.
Unit
L
N2 Process gasg
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
nitrogen, liquid
Uncertainty
No range defined.
Unit
g
Copper sulfate pentahydrate (electroless) 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
copper sulfate
Uncertainty
No range defined.
Unit
g
Copper anodes (pattern plating) Process chemicalg
Derivation basis
  • Calculated from per-operation consumption, operation counts, and manufacturing yield.
  • 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
No range defined.
Unit
g
Formaldehyde solution 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
formaldehyde
Uncertainty
No range defined.
Unit
g
Palladium chloride 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
proxy-mapped
Background dataset
palladium
Notes
Proxy mapping uses 60% of the material mass.
Uncertainty
No range defined.
Unit
g
Nickel sulfate hexahydrate 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
nickel sulfate
Uncertainty
No range defined.
Unit
g
Sodium hypophosphite 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
proxy-mapped
Background dataset
sodium phosphate
Uncertainty
No range defined.
Unit
g
Gold potassium cyanide 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
proxy-mapped
Background dataset
gold
Notes
Proxy mapping uses 68.4% of the material mass.
Uncertainty
No range defined.
Unit
g
Potassium permanganate 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
potassium permanganate
Uncertainty
No range defined.
Unit
g
Dry film photoresist 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
proxy-mapped
Background dataset
methyl methacrylate
Uncertainty
No range defined.
Unit
g

Outputs and waste

Spent CMP slurry 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:
  • SemiAnalysis and IEEE hybrid bonding process flow
  • A-STAR Singapore hybrid bonding research
  • BusinessWorld and TweakTown HBM4 specifications
  • All About Circuits and Kynix HBM4 specifications
Background data
ecoinvent 3.12 treatment route
Background dataset
treatment of hazardous waste, underground deposit
Uncertainty
No range defined.
Unit
g
Copper in wastewater-treatment sludge/recovery 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 dry film resist 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 waste plastic, mixture, municipal incineration
Uncertainty
No range defined.
Unit
g
Manganate desmear sludge 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
Solder mask develop sludge (unpolymerized resin) 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 waste plastic, mixture, municipal incineration
Uncertainty
No range defined.
Unit
g
Phosphorus in wastewater-treatment 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

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 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
Formaldehyde 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)
Formula
HCHO
CAS number
50-00-0
ecoinvent 3.12 elementary flow
Formaldehyde
Uncertainty
No range defined.
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.

Dissolved copper 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
Cu
CAS number
7440-50-8
ecoinvent 3.12 elementary flow
Copper ion
Uncertainty
No range defined.
Unit
g
Dissolved nickel 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
No range defined.
Unit
g
Free cyanide 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
CN-
CAS number
57-12-5
ecoinvent 3.12 elementary flow
Cyanide
Uncertainty
No range defined.
Unit
g
Phosphorus (from hypophosphite) 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
P
CAS number
7723-14-0
ecoinvent 3.12 elementary flow
Phosphorus
Uncertainty
No range defined.
Unit
g

Flows not quantified

3 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)

Package Mass Materialkg
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
cut off
Background dataset
Not applicable: this flow is not quantified in the inventory.
Reason
Mass-tracking record from the authored model – a package-level mass total, not an individual material input. It is recorded for transparency and excluded from upstream linkage; the package's constituent materials are not itemized in this dataset.
Uncertainty
No range defined.
Unit
kg

Not modelled (2)

CMP slurry (colloidal silica) 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
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
g
SC-1 solution (NH4OH/H2O2/H2O) 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
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
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.

  • The back-side illumination thinning, colour-filter array and microlens steps this product advertises are declared deferred on the wafer dataset it references, so they are absent from this inventory as well.

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