Superior Die Attach Performance & Lifetime of your Device

Power Electronics Sintering

Ag Sintering Overview is the process of compacting and forming a void-free, solid joint by heat and pressure without melting it to the point of liquification. Due to the increasing electrical and operating temperature requirements of high power devices, conventional solder materials do not always provide the optimal die-attach solution. While sintering of powders is not a new technology, the utilization of silver sintering for die-attach is still a relatively young and emerging technology. Some of the markets for this technology include the aerospace, locomotive, & automotive industries. The worldwide push to develop more efficient EV and Hybrid EV vehicles, for example, requires improving the reliability and efficiency of high current switching devices which are constantly cycled on and off. Depending on the materials selected, Sintering Technologies have the ability to greatly improve die-attach reliability with some key advantages:

  • Void-Free & Lead-Free Bonds - improved reliability & performance of component
  • Improved Thermal Conductivity - thermal conductivities up to 300 W/mK are possible
  • Reduced Electrical Resistance - Ag & Cu Sintering Materials offer excellent electrical performance
  • Absence of "Solder Fatigue" - the breakdown of the bonded joint after thermal & electrical cycling
  • Higher Melting Point of Bonded Materials - allows for higher operating temperatures of the final component

Materials used for Ag Sintering Die-Attach include many forms of Paste, Die-Transfer Films, or even Preform formats on tape & reel. Substrates for Sintering Die-Attach are typically Direct Bonded Copper (DBC) - sandwiched copper layers with a middle ceramic layer (AlN). One example of a sintering material used is Argomax®, an Alpha Assembly Solutions product, which is available for both Silver and Copper Sintering. As a reference, some of Argomax®'s product specs. include: High Thermal Conductivity Bond Lines ~250 W/mK, Bond lines from 5µm to 100µm, Pressures around 5-10 MPa or higher, & Process Temps from 190°C to 300°C.

Sintering Fig. Densification & Grain Growth at the Sintered Die-Attach Interface