Many modern vehicles feature significant functions, like Bluetooth, electric windows, GPS, and self-driving functionalities. These features and functionalities, coupled with electric vehicle technology, make electromagnetic shielding a concern in the automotive industry.
Electromagnetic interference, if not controlled, may damage components or cause electronic malfunctions and errors on vehicle equipment. EMI shielding minimizes such problems by preventing interference from errant signals.
Consequently, the EMI shielding market is expected to skyrocket at a high rate hitting approximately $10.6 billion by 2030. The core drivers are rapid industrialization and significant growth in the automotive industry, among other factors.
Let’s talk about the growing trend of EMI shielding automotive.
What is EMI shielding?
EMI shielding is the practice of averting radio frequency interference (RFI) from damaging sensitive mechanical devices. It involves using die-cut materials like EMI shielding laminates positioned in the way of electromagnetic interference. The materials then absorb or reflect the electromagnetic radiation to shield electronic devices from malfunctioning.
EMI shielding is common in different industries, including consumer electronics, automotive, telecom & IT, and aerospace.
There are various EMI shielding materials, including metals, conductive coatings, and laminates for the automotive industry. This post focuses on EMI shielding laminates in the automotive industry.
Applications of EMI Shielding in Automotive Manufacturing
The advancing technology has caused a spike in the need for electrical and electronic systems in vehicles. Systems such as control area networks (CAN), communications, safety systems, and infotainment systems like DC motors and controllers are now common in new cars.
But with a large number of electronic systems in confined places, the electromagnetic interference (EMI) of the systems is likely to interfere with each other. This happens through radiated or conducted emissions (crosstalk).
The interference causes system malfunction or failure if not properly controlled. With the increased demand for electric cars, the need for EMI shielding solutions is vital more than ever.
EMI adversely affects the performance of an integrated circuit internally and other electronic components within close range in an automotive electronic system. Additionally, EMI from external sources like mobile phones and commercial broadcasting signals can interfere with the vehicle’s electronic system when close to the transmitting antenna.
EMI can affect mission-critical systems, including;
- Console applications
- Infotainment head unit
- Power steering module
- Tire pressure monitoring
- Collision avoidance radar
- Electronic braking system
- Adaptive cruise control
How do you calculate shielding effectiveness?
As the market for automotive EMI shielding continues to grow, more solutions are coming to light. However, not all EMI shielding is effective. EMI shielding materials work at different efficiency levels. Therefore, it’s crucial to calculate the shielding effectiveness of a particular EMI shield to make your vehicle safe.
There are specific tests and standards for calculating EMI shielding effectiveness in automotive. Attenuation is among the vital indicators for calculating EMI shielding effectiveness and is measured in decibels. It measures the electromagnetic signal’s intensity before and after shielding.
Typically, an EMI material with a 10-30db shielding range is considered as least effective. Conversely, EMI shielding of more than 60 db is considered effective. Ideally, EMI shielding materials with high decibels are considered the most effective.
However, determining the attenuation level for a particular EMI shield can be complex. You can use various methods to retrieve results, depending on the type of EMI shielding. They include:
- Open field test
- Shielded box test
- Coaxial transmission line test
- Shielded room test
What is the best material for RF shielding?
Radiofrequency (RF) shielding refers to blocking RF electromagnetic radiation using electromagnetic shielding. It’s done by installing shields made of magnetic and conductive materials around the circuitry of electronic devices and cable lines. The RFI shielding effectiveness depends on the shielding material’s magnetic permeability and electrical conductivity, among other factors.
Copper is the best EMI shielding material for automotive wire shielding. This is because it is highly effective in attenuating and absorbing magnetic and electric components of electromagnetic waves. Also, copper has high electrical conductivity and is easily manufactured into various shapes.
What are the EMI EMC standards?
All electrical and electronic devices must have electromagnetic compatibility (EMC) to overcome EMI. However, there are various EMC standards that spell out the acceptable limit of EMI in electrical and electronic systems. EMC standards regulate devices’ operations, preventing communication disturbance of devices nearby.
There are specific EM standards for each industry. For instance, EMC standards in the automotive industry include SAE, ISO7637, ISO1145-1, IEC CISPR-25, and ISO1145-2. These standards regulate procedures and measuring techniques.
How to shield electrical wires
Jacketing may protect a cable from environmental moisture, mechanical abrasion, and spills, but not from EMI that requires advanced shielding.
Data and cable signals must be shielded using electromagnetic shielding materials to reduce the effects of EMI. However, various factors can affect the type of cable shielding, including signal and noise frequency, cable length, and termination methodology. There are two types of shielding electrical wires;
- Foil shields – use a thin metallic layer reinforced with a polymeric layer that offers up to 100% cable shielding.
- Braided shields – these are simply woven meshes of wire offering up to 95% cable shielding.
EMI shielding in the Automotive manufacturing
There are various electronic devices in motor vehicles emitting different levels of radiation. This is why EMI shielding has gained popularity in automotive manufacturing. EMI is a common concern in vehicle design, manufacturing, and engineering.
Most vehicle manufacturers want to create electric cars that are resistant to EMI interferences. Radiated EMI is common in electric and hybrid cars and stems from electric current flowing through circuits, wires, and other electrical components of a vehicle.
Conducted EMI in cars comes from current flowing through the vehicle’s chassis. EMI shielding helps prevent the spread (and effects) of EMI in vehicles.
Electric and hybrid vehicles have multiple electrical functions, which are vital to the overall performance of the vehicle. However, electromagnetic interference is a common concern in automotive manufacturing as it can cause damage or malfunctions on electrical vehicle components.
EMI shielding helps prevent the effects of EMI by blocking the radiation and interferences. There are various EMI shielding materials, including EMI laminates. The effectiveness of the shielding depends on the type of material used and the strength of the signals. Contact Lamart Corp to learn more about custom laminations to shield electrical components.