After an irradiation time of less than one second, the build-up of adhesion is already significant; after five seconds, the compression shear strength on glass even reaches 18 MPa. The adhesive also ensures good adhesion to other typical optoelectronic substrates such as aluminum, FR4, PPS, or LCP.
The milky epoxy resin with medium viscosity cures under UV light at a wavelength of 365 nm in layers of up to 1.5 mm thickness. In the case of thicker adhesive layers or shadowed areas, which are not reached by the light due to the component’s geometry, the dual-curing adhesive will be exposed to heat for full polymerization. This process typically takes places at + 80 °C for 50 minutes.
The product features reduced outgassing and shrinkage, both being important characteristics for optical precision. Its low coefficient of thermal expansion (CTE), matching both electronic components and PCBs (printed circuit boards), ensures a high optical quality, even in case of temperature fluctuations.
Modified for Special Optical Requirements
DELO DUALBOND OB786 is available in additional modified versions, for example, in black to shield the ray path or optical elements and absorb scattered light. Another option is the white version which provides increased reflection and leads to a higher light yield. Furthermore, this product has smaller-sized fillers, making the adhesive suitable for even more miniaturized applications.