To cement the move, DELO has completed a reseller agreement with APPEX. Through 40 years of history, APPEX has developed from a small company focusing on maintenance of optical lenses into a high-tech company providing services from full-fledged manufacturing of sensitive equipment for next generation IC, including all complementing disciplines, as well as design and manufacturing of automation systems for customer demand.
Also, being a distributer for sophisticated process and measuring equipment for the semiconductor market, as well as for vacuum products such as dry pumps, leak detectors, sensors and gauges, APPEX is a partner of several well-known domestic enterprises, including Canon, Canon Marketing Japan and high-tech companies like Pfeiffer and Trumpf.
Says Robert Saller, head of sales international at DELO: “We selected APPEX because of their capabilities and experience in electronics, optoelectronics and semiconductor manufacturing.”
Meanwhile, DELO has unveiled a new hybrid adhesive for the automotive and electronics industry – an epoxy resin that is light-fixable for the high-reliability sector. Particularly resistant epoxy resin adhesives with special hardeners are used where bonded or encapsulated components are exposed to extreme temperatures and aggressive chemicals.
“However, only heat-curing variants have been available up to now,” advises DELO. “By contrast, the light curing of the newly developed product offers greater bonding accuracy, a defined fillet and easier handling of the cured components. What's more, in the case of glob top encapsulation, it forms a skin and can ‘freeze’ its shape, so it does not flow away during heat curing. This means that a defined glob top encapsulation is possible, even if miniaturisation makes space tight on the circuit board, which saves one process step, compared to the alternative Dam & Fill method.”
In a two-stage curing process, the adhesive is first light-cured in 1-5 seconds, depending on intensity, and achieves a die shear strength of more than 1 N on the FR4 circuit board material. Heat curing is still required – for example, 30 minutes at 150°C, after which the full strength of 50 MPa on FR4 is attained.
The dual-curing product has universal adhesion and is available in one viscosity for bonding applications and another for encapsulation. Both variants are said to be easy to work with, thanks to their thixotropic flow characteristics. Their temperature range of DELO extends from -65°C to 180°C.
For even higher thermal requirements, DELO has recently introduced high-temperature adhesives to the market – namely, its anhydride-based adhesives – which are temperature-resistant up to 250°C. They are said to remain strong and stable in temperatures up to +250°C. “That is 70 °C more than previous standard products based on anhydrides,” says the company. “Even after 500 hours of storage at +250°C, they exhibit a tensile strength of 50 MPa. As well as a high temperature-resistance, the adhesives also have a high bond strength at temperatures above +200°C. After storage for 500 hours at +250°C, a compression shear strength of 8 MPa was achieved at a test temperature of +220°C.
Despite its hybrid nature, the epoxy resin is, maintains DELO, highly resistant to chemicals. “Even after 500 hours stored in aggressive media, like transmission fluid, gasoline, or methanol, there is hardly any effect on its mechanical properties. The product also exhibits good resistance to printing inks, which attack most adhesives. It is therefore particularly suitable for adhesive applications in the print head that require highly accurate positioning – eg, bonding the nozzle plate to the interposer.”
DELO has also released three new highly flexible acrylates especially for sealing and casting small-volume applications, such as relays, microswitches, and pins. The adhesives combine opposing properties. “They are highly flexible and yet at the same time resistant to temperatures,” says DELO. “They fully cure within seconds, enabling fast production processes and a high yield rate. In addition, the adhesives have a universal adhesion, are highly flexible, and balance tension.” Their temperature limit is 120°C.
In addition to the existing benefits, the new sealants, according to DELO, have “taken a considerable leap in temperature and retain their flexibility, even at temperatures of up to 150°C. This can be clearly seen with a constant Young’s modulus, as, even after 1,000 hours of temperature storage at 150°C, it remains low. In addition, the acrylates have excellent sealing properties, as is demonstrated during a thermal shock test from -40°C through 150°C. The products exhibit full leak-tightness here, even after 300 cycles. These are important criteria, particularly for bondings in the automotive field”.
The new sealants are the purely light-curing DELO-PHOTOBOND GE4009, the light- and heat-curing DELO-DUALBOND GE4707, and the light- and moisture-curing DELO-DUALBOND GE4906. Both dual-curing adhesives are particularly suited to applications with shadow areas.
