New dual-curing UV acrylic adhesives 22 May 2023

With the introduction of Vitralit® UD 8055 and Vitralit® UD 8056, Panacol continues to expand its portfolio of dual-curing acrylic adhesive systems. Thanks to their characteristics, the two new adhesives are ideal for use as encapsulants that provide environmental protection to sensors and PCB components.

A high glass transition range (Tg) is particularly important when encapsulations and bonded substrates must withstand thermal stress over long periods of time. Exceeding 100°C, the Tg of Vitralit® UD 8055 and Vitralit® UD 8056 ensures that thermal expansion coefficients behave homogeneously in the application area. This prevents the adhesive from losing bond strength and creating excessive stress between components which can lead to delamination or cracking in the electronics. Vitralit® UD 8055 and Vitralit® UD 8056 were primarily developed for the production of sensors, PCBs and flex PCBs that are used in consumer and automotive electronics.

These adhesives principally cure with UV light and also possess a secondary moisture post-cure mechanism to compensate for shadowed areas. A special characteristic of these two adhesive systems is their high glass transition range of over 100°C, which helps to preserve high-strength bonds through thermal cycling stress.

UD 8055 and UD 8056 can also be used for bonding dissimilar substrates, including many plastics and metals where undercuts or geometry-related cavities are present. It is here that the secondary moisture cure mechanism overcomes the challenge of shadowed bond lines and ensures a reliable bonding process. 

In the primary UV curing process, the bonded areas in the component are fixtured in seconds by UV light. LED curing systems can be used possessing wavelengths of 365Nm or 405Nm. Also, LED systems do not require any warm-up phases and thus enable the shortest cycle times.

In the secondary post-curing process, uncured monomers crosslink in shadowed areas by atmospheric moisture without stress and the need for secondary thermal exposure. This technology enables fast cycle times and high-volume production without subjecting temperature-sensitive electronics or components to excessive thermal stress.

Panacol states Vitralit® UD 8055 and Vitralit® UD 8056 achieve high adhesion with typical substrates such as FR4, PC and PBT. The company also insists that Vitralit® UD 8055 has demonstrated very reliable adhesive performance through challenging 85/85 aging tests, and that Vitralit® UD 8056 demonstrates high performance on LCP and has passed UL94 HB tests.

Becca England Assistant Editor t: +44 (0) 1727 615 413

Becca is the latest member to join our team and is eager to get stuck into the world of fasteners. She brings an enthusiastic and fresh outlook on what we do editorially and will be leading our social media activity – including sourcing material, editing articles and posting online.