With the new ‘Black&Light’ adhesives, Panacol has developed a new adhesive technology: deep curing black epoxies. Black epoxy adhesives from Panacol's Vitralit® product range can now be cured with UV light sources in thicker layers, without resorting to secondary curing mechanisms, notes a press release from the German-based company.

Conventional black UV adhesives have a major disadvantage: the black color absorbs a high proportion of the UV intensity, which means that the energy needed to fully polymerize an adhesive can only penetrate a few micrometers. This results in surface “skin” formation on black adhesives, but not a complete cure. They must then be cured in a secondary thermal curing process at temperatures above 100°C.

Panacol's new ‘Black&Light’ technology enables the complete curing of black epoxy adhesives with LED UV energy.  Depth of cure can range from a few hundred micrometers to several millimeters. The adhesives are suitable for encapsulation, glob top, or edge bonding in electronics manufacturing, as well as for optical adhesive systems where high OD values (optical density) are required.  They are suitable for optoelectronic applications to help minimize reflections and enhance sensor transmission values.

A typical manufacturing process using ‘Black&Light’ technology can be as follows: The black adhesive is dispensed and cured with the appropriate wavelength and intensity. During the curing process, the ‘Black&Light’ technology within the adhesive enables the UV rays to penetrate and complete a full cure.  Once the adhesive polymerization is complete, the structure of the ‘Black&Light’ technology prohibits light transmission, resulting in a fully cured adhesive system that remains irreversibly black.

The ‘Black&Light’ technology is compatible with many Vitralit® epoxy adhesives from Panacol.  Custom adhesive solutions can be created to accommodate unique requirements for amount of light blocking and depth of cure.  The ‘Black&Light’ adhesive systems can be very specifically adapted to specifications of the respective application.

Another major advantage of the ‘Black&Light’ adhesives is storage.  Many single-component, black epoxies require deep frozen transportation and storage. The ‘Black&Light’ epoxy adhesives can be stored and shipped at room temperature or under normal refrigeration.