Optical sensors
System Definition - Goal and scope
Definition
Optical/image sensor = device that detects and converts light rays into electrical signals, that can be viewed, analyzed, or stored
Context : In smartphones and cameras, the number of image sensors is increasing. No environmental data available
What is it used for?
They are used in phones, cars, laptops, tablets, industrial/medical systems, security cameras, cars and other vehicles, etc.
Are there different types/technologies?
Two main types :
Charge-coupled device (CCD)
Active-pixel sensor (CMOS sensor) → cheaper, low electricity consumption. They are more used in modern cameras.
IR sensor (for night vision)
CDDs' characteristics:
Global shutter
Low noise
High dynamic range
Medium range frame rates
Subject to smearing
Moderm CMOS characteristics:
If different types, what are the differences in terms of materials, process, use consumption?
Is there a generic component that represents a family of components?
How many sub-parts does the system consist of?
The main parts of a CMOS image sensor are the following:
Sensor chip (wafer)
Wire bonds
Package
Cover glass
Contact pads
Sources :
Perimeter
What is included?
What is excluded?
Functional unit and reference flows
What is the functional unit?
What are the reference flows?
Life Cycle - Inventory
⇒ Goal: Define state of the art on life cycle stages to be considered.
What are the already existing data (dataset, parametric model, paper, etc.)?
Raw materials
⇒ Goal: List the technical information needed for the LCI.
What is it made of?
Who are the main mining? Where are they located?
Manufacturing
⇒ Goal: List the technical information needed for the LCI.
For each system sub-part:
What are the manufacturing processes?
What are the assembly processes?
For each process, what is the energy consumption?
For each process, what is the yield? Are they co-products and/or losses?
How the “main” manufacturers can be characterized: by the number of components manufactured, the market share (€), other?
Who are the main manufacturers? Where are they located?
Sony corporation (Japan, Integrated Device Manufacturer (IDM))
Samsung Electronics (South Korea, IDM)
OmniVision Technologies (US, fabless)
onsemi (US, IDM)
STMicroelectronics (CH, IDM)
Source
Distribution and packaging
⇒ Goal: List the technical information needed for the LCI.
What are the packaging? Made of which materials?
Which are the transport modes?
What are the transport distances?
Use
⇒ Goal: List the technical information needed for the LCI.
What is the service lifespan? (durée d'utilisation)
Is there a reparation factor?
Is there sub-parts replacement?
Where is it used?
Who are the users?
Which + how much energy does it need?
Is there emissions from use?
End of life
⇒ Goal: List the technical information needed for the LCI.
What is the lifetime? (durée de vie)
Is it different from lifespan and why?
Is it refurbished? + Where?
Is it recyclable? Can it be dismantled? Which material can be separated? + Where and how?
Is it incinerated with energy recovery? Just incinerated? Buried? + Where?
Which part of waste can be considered as mismanaged (neither recycled, nor incinerated, nor buried)?
Environmental assessment
⇒ Goal: Define state of the art on environmental impacts.
What are the impact assessment methods used (EF, ReCiPe, others)?
What are the known environmental impacts associated to the system (indicators)?
What are the known hotspots? Which raw material? Which life stage?
CCD / CMOS
Mono / color sensor
Resolution → sensor size
Pixel size → sensor size
What are the potential parameters affecting environmental impacts?
What are the main source of uncertainty?
Bibliography
⇒ Goal: Source every data we cited previously
List of our sources
Data origin: bibliographic source / consortium hypothesis / expert opinion - required if a Data Quality Rating (DQR) must be completed
Next steps
⇒ Goal: List challenges and clarify priority areas for action
What do we know we don't know?
What are the identified challenges?
What paths/ideas should be explored?