UV Die Bonding

Cure in Place, Hold Placement Accuracy

UV die bonding, or UV/dual-cure adhesive attach, has the main advantage of being curable in situ, significantly speeding up the entire assembly process and opening up the range of applications to some specific cases. UV-curable adhesives cure in the presence of 365–400 nm wavelength light.

In-Situ Curing and Dual-Cure Flexibility

Bonders equipped with these specific-wavelength light sources on the bond head can cure the adhesive while the bonder still holds the component in place. This maintains placement precision and accuracy independent of adhesive growth or shrinkage.

Some adhesives are also dual-cure, meaning they can cure through both light and heat, or even moisture in some cases. This allows quick "tacking" of the component with minimal light exposure, usually one to two seconds, to maintain placement accuracy while leaving final curing to a batch oven process. Dual-cure adhesives can also cure at lower temperatures than thermally cured epoxies, providing an avenue for extremely thermally sensitive assemblies such as those found in the medical field.

Controlled UV Curing for Clear Lens Attach

Many light-cure adhesives are clear, which opens up optical applications. With careful control of the curing process, the adhesive can secure a lens in place via near-encapsulation while still allowing it to function optimally.

This careful control usually requires programmable UV intensity, to the extent that a "UV light profile" is created. Palomar die bonding systems offer this capability to help ensure the adhesive cures without defects or "spider-webbing."