DELO Releases New Anti-yellowing Automotive Lighting Adhesive

DELO, manufacturer of industrial adhesives for the automotive, consumer electronics and semiconductor industries, announces the development of a new adhesive DELO PHOTOBOND for automotive lighting applications
OB4189. The adhesive is resistant to yellowing and has a high aspect ratio, making it particularly suitable for bonding microlens arrays, such as microlenses in automotive headlights and projection systems.

Today, lighting is one of the fundamental elements of automotive design and differentiation, and microlens arrays are a key factor in the development of both areas. The microlens array projects LED light with a focal length (focal
length) are extremely short, providing sharp images and unique geometries. Microlens array systems are increasingly being used as optical components in automotive headlights and projection systems due to their low installation depth requirements.

To improve efficiency, these microlenses are usually made of photopolymers (ie, adhesives), and the microlens arrays are then fixed to the mounting housing. DELO PHOTOBOND
The OB4189 adhesive has a viscosity of 75,000mPa·s and can achieve high aspect ratio bonding. As a result, the adhesive retains its shape after application and does not flow, which is critical for bonding microlens arrays. Additionally, the adhesive is extremely resistant to yellowing, which is important for optically demanding applications, as confirmed by lifecycle simulations at 140°C for up to 500 hours.

The modified acrylate (modified
acrylate) does not contain solvents, the application temperature range is -40 ° C to +120 ° C, the compressive shear strength (compressive shear) on polycarbonate (polycarbonate)
strength) is 30MPa, and the compressive shear strength on polymethyl methacrylate (PMMA) is 25MPa. In addition, the compound can be cured with ultraviolet light (365nm) and visible light (400nm), and at 400nm wavelength, the typical exposure time of 100μm layer thickness (exposure
time) is 5 seconds. This enables a high-precision active alignment process and low-cycle automated production of optical components.

Christoph Appel, product manager of DELO LED (automotive direction), said: “DELO PHOTOBOND
OB4189 is a new high-viscosity, extremely yellowing-resistant product in DELO’s portfolio of temperature- and moisture-resistant active alignment adhesives that precisely meets the requirements of microlens arrays. ”