FEATURE

Using Pressure-Sensitive Tapes to Meet the Evolving Needs of the Automotive Industry

Pressure-sensitive adhesive tapes offer functionality, versatility, and customization as the automotive industry produces more EVs and increases the integration of electronic systems into vehicles.

By Scott Krusinski, Product Manager, Automotive and Other Transportation, Avery Dennison Performance Tapes

Anyone who has been shopping for a new vehicle recently has seen evidence of how the auto industry is evolving and the direction it is going. The two major trends influencing auto design and manufacturing at all levels of the supply chain fall under the classification of electrification. The first involves the continuing integration of electronic systems into vehicles, particularly advanced driver assistance systems (ADAS) such as guided cruise control and parking assist systems. The second is the shift by virtually every manufacturer to electric vehicles (EV).

Both trends create opportunities for pressure-sensitive adhesive tapes (PSATs). PSATs offer the functionality, versatility, and customization to address a wide range of challenges OEMs and their suppliers face while navigating the changes occurring in the industry.

Vehicle Electronics

While today’s vehicles are already incredibly sophisticated electronically, the increased use of ADAS technologies introduces new challenges that must be addressed. Key components of these systems—cameras, sensors, and lidar and radar systems—are often mounted on or near the outside of the vehicle where they are exposed to environmental factors that can affect their performance. That means they may require special protection from ice buildup, electromagnetic (EMI) interference, dust, vibration, and glare.

PSATs from leading manufacturers like Avery Dennison Performance Tapes are engineered to make ADAS technologies more durable and useful. They provide strong bonding with the substrates used in ADAS components and can protect components from the various factors that can reduce performance and durability. Specifically, PSATs can support:

• Bonding: Pressure-sensitive tapes provide a better solution for bonding ADAS components to each other and to the vehicle than mechanical fasteners or liquid adhesives. They’re easy to apply, require no time to cure, and can be engineered to withstand conditions experienced by vehicles operating in a range of climates.
• Mounting and sealing: Double-coated polyethylene (PE) foam and acrylic foam bonding (AFB) tapes provide a cost-effective alternative to mechanical fasteners for mounting, sealing, and damping of ADAS technologies. Through their application, manufacturers can ensure reliable mounting, prevent dust and water from reaching electrical components, and reduce the vibration that can affect vision and sensing.
• Gasket bonding and BSR reduction: Rigid electronic components often use laminated die cut foam or fibrous materials between components to absorb vibration, cushion impacts, fill gaps, and mitigate buzz squeak and rattle (BSR). PSATs using these materials create strong bonds with the dense urethane and EPDM foam to optimize ADAS components mounted on the exterior of the vehicle.
• PTC heater film bonding: Positive temperature coefficient (PTC) heater films attached to or around ADAS cameras, lidar, radar, and ultrasonic sensors can combat ice buildup and enable reliable operation in freezing temperatures. Thin bonding tapes, such as those in the Avery Dennison Core Series™, bond PTC heaters to ADAS components. Polyethylene foam tapes can also be used to fill gaps between rigid components in this application. These tape solutions can also support flexible printed circuits (FPCs) being used for applications such as hands-off detection on steering wheels or occupancy sensors in seating.
• Light management: Improperly managed light can negatively impact cameras and displays. Specialty tapes can be used for light management purposes such as glare reduction, infrared light blocking, full light blocking, visible light reflecting, and more.

Vehicle Electrification

The transition to EVs represents a potentially greater disruption to the industry than ADAS technologies. The key to the success of EVs lies largely with the battery system, and significant resources are being devoted to EV battery design and manufacturing. As EV batteries evolve, pressure-sensitive tapes are playing an increasingly important role in enabling batteries to meet OEM requirements. Here are the key applications for tapes in EV batteries.

• Thermal runaway protection: Preventing thermal runaway is a top priority for every EV battery manufacturer. Mica, ceramic fibers, and other materials are used for this purpose. Pressure-sensitive tapes bond these materials to cells, modules, and pack structures. These tapes feature flame-retardant adhesives that enable composites and materials to meet UL 94 V-0 and other flame requirements. They can also be constructed with easy release liners to prevent cohesive failure of delicate fibrous-based materials.
• Flexible busbar protection: Flexible busbars offer flexibility, safety, and cost effectiveness in EV battery applications. PSATs represent an excellent solution for protecting these flexible, printed circuits. They provide electrical insulation and flame resistance in accordance with UL 94 V-0. Dielectric material and adhesives are also available that are tested for breakdown voltage and dielectric strength requirements using GB/T 1408.1-2016 and ASTM D3755 test methods.
• Thermal interface: Flame retardant adhesive tapes are being used to bond thermal interface materials (TIMs), such as thermal gap pads, to a heat sink or chiller plate to enable thermal management. Solutions include silicone-based adhesive tapes for use with silicone TIMs and acrylic-based tapes for use with non-silicone-based TIMs.
• Cell-to-cell bonding: Adhesive tapes are a quick and strong solution for providing structural integrity in an EV battery pack. Using tapes to bond pouch and/or prismatic cells together eliminates the curing times and component mixing that are required with liquid adhesives. Additional functionality can also be added to the tape to meet flame retardant or electrical requirements.
• Electrical insulation and cell wrapping: Electrical insulation and cell wrapping are critical for protecting sensitive components in EV batteries. Single- and double-coated tapes are available that incorporate dielectric films that are tested using GB/T 1408.1-2016 and ASTM D3755 test methods. Double-coated tapes can be combined with other materials, such as compression pads, to achieve electrical insulation. Single-coated tapes can be applied to rigid materials, such as aluminum chill plates and other metal structures. These tapes can use flame-retardant adhesives for dual dielectric and flame protection.
• Compression pads: Individual prismatic and pouch cells in EV battery packs need protection from impact and movement. Placing foams backed with pressure-sensitive tape between each cell provides full coverage adhesion between the metalized polyester pouch cell and cushion foam. These tape solutions can also act as an assembly aid because bonding is achieved immediately upon application. As with other applications, flame-retardant and dielectric tapes are available for applications where these capabilities are required.
• Pack seal and gasketing: Creating a tight seal for components is critical in the construction of EV battery assemblies. Heat-activated and pressure-sensitive acrylic foam tapes are ideal for extrusions and rigid material bonding. They provide high durability and strength for demanding environments, shock absorption, and dynamic resistance. The acrylic foam core enables gap filling between rigid components, and continuous bond line helps seal out unwanted intrusion and reduces the need for fasteners.

Collaborating to Develop Solutions

PSATs are already widely used in automobile manufacturing, and the growth in ADAS technologies and EVs will open new opportunities to leverage the durability and functionality of PSATs to ensure the reliability and performance of EV batteries and driver-assistance technologies. In many cases, proven solutions are available today, but tape manufacturers like Avery Dennison can also work with converters, suppliers, and manufacturers to develop custom solutions for evolving applications.