May/29/2012 10:26 Filed in: Liquid Epoxy
I gave a presentation this month at the IMAPS New England Symposium on a new nanoparticle silver epoxy that can be aerosolized into droplets less than five microns in diameter. These droplets can then be jetted in multiple axes to create bond pads or interconnects with very fine features. Unlike traditional die attach epoxies that are needle dispensed by touching the surface and drawing out a relatively large single drop of liquid adhesive, an aerosolized epoxy is “painted” on a substrate with a laser-like beam of tiny droplets using a dispense head that can be 10 mm from the surface. Even ink jet dispensing does not have the resolution of aerosol jetting. For more details, download the complete presentation. In addition to explaining the aerosol jet process, it describes the epoxy properties, especially highlighting its very high electrical conductivity. For those who don’t currently have access to an Optomec Aerosol Jet® system, Resin Designs has created a needle dispense version. While the benefits of aerosol jetting won’t be realized, the finest needles can be used (32 gauge and smaller) to begin experiencing the potential of this new technology. As shown in this photo of a Kovar tab bonded to a gold surface, this adhesive looks more like liquid silver than a traditional die attach material. We’ll have more about these new materials in future updates. If you have a potential application, please let us know.
May/01/2012 12:00 Filed in: Polyurethane
In protecting an LED or photovoltaic cell circuit with a clear cover, a piece of glass does a great job. Alternatively, a see-through encapsulant could be used, and in this case, the “clear” choice is Resin Designs Urethane 53051. This tough polymer has high moisture resistance, and very importantly, does not yellow with long exposure to light, including UV. With an operational temperature range of -50° to +110°C, this robust polymer will tolerate most any environment. It is a two-part material that gels up in just a few minutes after mixing and cures completely after 24 hours. If desired, curing can be accelerated with exposure to heat. For more information, download the technical data sheet or contact us.