Customer’s Application
The client is a Tier-1 automotive supplier that engineers and manufactures a range of critical engine management sensors for global automotive OEMs. The specific application involves potting the sensitive electronics of an oil pressure sensor designed for the latest generation of turbocharged gasoline direct-injection (GDI) engines. The sensor is mounted directly on the engine block, placing it in one of the most hostile environments in a modern vehicle.
The Engineering Challenge
The under-hood environment of a modern, high-output engine subjects electronic components to a relentless assault of thermal, chemical, and mechanical stresses.
- High Temperatures and Thermal Shock: The sensor must operate flawlessly while exposed to constant ambient temperatures ranging from 150°C to 180°C. This requires a high-temperature epoxy that can endure severe and frequent thermal shocks, transitioning from a sub-zero cold start (-40°C) to full operating temperature in a matter of minutes. This rapid expansion and contraction will cause materials with mismatched coefficients of thermal expansion (CTE) to crack, delaminate, and ultimately fail.
- Aggressive Chemical Exposure: The sensor assembly is continuously immersed in hot, chemically aggressive engine oil, which contains a complex mixture of detergents and additives. It is also exposed to fuel vapours, glycol from the cooling system, and various cleaning solvents. An inadequate high-temperature bonding adhesive will soften, swell, or chemically degrade, allowing these fluids to penetrate the housing and cause a fatal short circuit in the electronics.
- Constant Vibration and Mechanical Stress: The sensor must withstand the constant, high-frequency vibrations generated by the engine’s operation. The potting compound is not just a sealant; it must act as a robust mechanical support, damping vibrations and protecting the delicate PCB, components, and solder joints from fatigue failure.
- Extreme Reliability Mandates: Automotive components are expected to have a service life of over 10 years and 150,000 miles. The industrial high-temperature epoxy must maintain its protective properties without any degradation over this entire lifespan to meet the stringent reliability and warranty requirements of the automotive industry.
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The Kohesi Bond Solution | Custom Engineered Certainty
To survive this punishing environment, the potting compound had to be selected based on a portfolio of high-performance properties.
- High Glass Transition Temperature (Tg
): A Tg significantly higher than the maximum operating temperature (e.g., > 190°C) is essential. This ensures the heat-resistant epoxy remains in its rigid, glassy state and does not soften, thereby maintaining its full mechanical strength and protective capabilities under extreme heat. - Low Coefficient of Thermal Expansion (CTE): A low CTE, closely matching that of the sensor’s metallic housing and ceramic PCB, is critical to minimising the stress induced during thermal shocks. This prevents the formation of cracks that would compromise the seal.
- Proven Chemical Resistance: The epoxy bonding adhesive must be specifically formulated and rigorously tested for long-term immersion resistance to automotive fluids, particularly synthetic engine oils and fuels, at elevated temperatures.
- High Adhesion and Mechanical Strength: To withstand constant vibration, the material must exhibit superior bond strength to metals and engineering plastics, combined with high compressive and tensile strength to provide durable mechanical support.
- Optimised Flow Properties: The viscosity of the epoxy for electronic components must be low enough to allow it to flow into all the intricate spaces of the sensor assembly, completely encapsulating the components and eliminating any air voids, which can trap moisture or create stress concentrations.
To meet the application’s rigorous demands, Kohesi Bond’s adhesive experts custom-formulated KB 1452 HT-2AOLV. This specialised, two-component epoxy is engineered for an exceptionally high glass transition temperature (Tg) and superior flow properties for seamless potting. It delivers first-rate mechanical strength and a low coefficient of thermal expansion (CTE) for long-term dimensional stability. Furthermore, KB 1452 HT-2AOLV acts as a superior automotive epoxy adhesive, exhibiting outstanding resistance to acids, bases, fuels, and solvents. They also provide a robust, high-strength bond across plastics, metals, and ceramics even under extreme thermal stress.
The Result
By implementing KB 1452 HT-2AOLV, the supplier dramatically enhanced sensor reliability, successfully passing a rigorous 2,000-hour validation test involving simultaneous thermal shock and chemical immersion. This durability breakthrough led to a 90% reduction in field failure rates, significantly lowering warranty expenses and improving the supplier’s quality rating with automotive OEMs. This proven robustness, enabled by KB 1452 HT-2AOLV, ultimately secured a lucrative next-generation contract for high-performance and commercial vehicle platforms.
Related Products
KB 1452 HT-2AO
Kohesi Bond KB 1452 HT-2AO is an exclusive two component epoxy system suitable for bonding, sealing, coating, potting and encapsulation applications. Read More
For a Tier-1 supplier, the investment in a premium potting compound like KB 1452 HT-2AOLV is a strategic safeguard against the catastrophic financial and reputational risks of a vehicle recall. Given that a single failed sensor can lead to engine seizure or multi-million-dollar logistics costs, the high-reliability performance of KB 1452 HT-2AOLV offers essential protection. By ensuring the integrity of the sensor, this Kohesi Bond solution protects the supplier’s core business, profitability, and standing in the global automotive supply chain.
Technical Specifications Summary
Parameter | Requirement | Significance |
Service Temperature Range | -40°C to +200°C | Ensures survival and performance during extreme under-hood temperature fluctuations. |
Glass Transition Temp (Tg | > 190°C | Guarantees material integrity and mechanical strength at peak engine operating temperatures. |
Chemical Resistance | Resistant to Engine Oil, Fuel, Glycol | Prevents degradation, swelling, or softening from long-term exposure to automotive fluids. |
Thermal Shock Resistance | Passes -40°C to +150°C, 1000 cycles | Critical for surviving the rapid temperature changes from engine heat-up and cool-down. |
Vibration Resistance | High (Dampens Harmonics) | Protects delicate electronic components and solder joints from fatigue failure due to engine vibration. |
Adhesion Strength (Lap Shear) | > 1,200 psi on Aluminum | Ensures a robust, permanent bond to the metallic sensor housing, preventing any leak paths. |
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Utsav Shah is a 34-year-old entrepreneur with a passion for scientific discovery. Utsav’s journey began with a deep dive into materials science, earning degrees from USC and the Institute of Chemical Technology. He’s the visionary founder of Kohesi Bond, a top-rated adhesive manufacturer, and Cenerge Engineering Solutions, a leader in heat exchangers and cryogenic pumps. With over a decade of experience, Utsav consults across various industries, ensuring they have the perfect adhesive solution for their needs. Connect with him on LinkedIn!
