Silver sintering technology has been around since the 1980s, but the process has faced numerous problems. The limits of traditional sintering, rapidly growing market demand, 5G, evolving technologies, issues of energy and eco-sustainability, as well as lead-free requirements have led many (including Palomar Technologies) to revisit these challenges. It must be emphasized in our case, in the context of pressure-less applications for high temperature applications, such as those used for RF power electronics.
This blog sets the stage for a series on silver sintering jet dispensing technologies. Included in this first review will be an examination of the advantages of
Silver vs. Lead and Gold
It has been amply demonstrated that Ag sintering material capability is beyond that of high-lead (Pb) in respect to:
Gold has been the historically preferred alloy due to its extraordinary physical properties. Price, scalability, and sustainability rule it out for long-term industrial use, however.
Against this backdrop, pressure-less silver sintering offers a cost-effective yet comparably efficient bond as lead and gold, and does so over widespread applications that secure void-free, strong, superior thermal and electrical conductivity. Silver has the ability to decrease the junction temperature (Tj) of a device up to 100°C. In the process, when the silver material is heated under optimal circumstances, its form will change from powder to a solid structure. Compared to traditional solder material, the action of sintering results in a more reliable bond, significantly increasing performance and lifetime, while being more energy efficient and placing less stress on the package.
In addition, pressure-less sintering as a process offers a series of other significant advantages:
In the next blog, we will set out to detail the background and justification behind the development work we undertook at our newly upgraded Innovation Center in Singapore, applying silver sintering on a series of test dies using a Palomar 3880 Die Bonder, retro-fitted with a Musashi high speed jetting dispenser. In particular, we will note that the jet dispense, though being a powerful and versatile tool, proved insufficient on its own to achieve a fixed height bond line with consistent low void results. Only when we developed a proprietary “Fixed BLT” software were a number of underlying problems solved. The final product consistently delivered exacting bond line specs with excellent planarity and a virtually void-free bond in a time-effective, commercially viable fashion.
To learn more about pressure-less silver sintering for RF Power Electronics, download our technical article: Energy and Eco-Sustainability using Pressure-less Silver Sintering for RF Power Electronics.