DELO now offers a dual-curing epoxy resin that can be used in the most demanding applications.
DELOMONOPOX VE 72768 offers greater bonding accuracy and is extremely resistant to substances like oil, transmission fluid, gasoline, methanol and printing ink. Designed with special hardeners, this new adhesive is used where bonded or encapsulated components are exposed to extreme temperatures and harsh chemicals.
Robert Saller, director sales international, DELO, said, “Up until now, only heat-curing adhesives have been available for high-reliability applications. By integrating the light fixing process, not only are we able to provide users with a greater bonding accuracy, but also a defined fillet and easier handling of the cured components.”
The new adhesive allows for defined glob top encapsulation even in the tightest spaces on a circuit board. With light curing, the glob top forms a skin and can ‘freeze’ its shape, so none of the adhesive flows away during the heat curing process. This eliminates one step in the process as compared to the dam and fill method, which is the only other encapsulation alternative in miniaturization.
Curing is achieved through a two-stage process. First, depending on intensity, the adhesive is light-fixed in up to 5 seconds to achieve a die shear strength of more than 1 N on the FR4 circuit board material. Then it is briefly heat cured (for example 30 minutes at 150°C) to obtain its full strength of 50 MPa on FR4.
The system is offered in two viscosities, one for bonding applications and another for encapsulation. Its operating temperature range is from -65°C to 180°C.