S-Bond 220M Developed for Silicon/Silicate Joining

The direct solder joining of silicon is difficult posing solder wetting and adherence challenges for many applications including electronic “die” packages, sensor chips and solar panels. The direct solder bonding to silicon (Si) has been limited by the wetting resistance of angstrom thick nascent silicon dioxide (SiO2) layers that naturally forms on silicon. To combat these solder bonding challenges, metal plating (vapor deposition of Ti and Ni) has been used. To address this challenge, S-Bond Technologies has developed and has recently been awarded a patent for its S-Bond 220M alloy which is a Sn-Ag-Ti-Ce-Ga + Mg alloy that has been optimized for direct Si solder bonding without flux nor plating. The new alloy bonds well to silicon, silica, and glass silicates based on a solder formulation that adds magnesium (Mg) in low enough levels that does not change the solder melt behavior but enhances the “active” nature of S-Bond alloys to interact with oxides of silicon and many other metals even more effectively than other active solders. These Mg modified active solders wet and adhere very well to silicon based on mechanical activation used in other active solders. (more…)

Metal Soldering with Active Solders

Active solders such as S-Bond have wide application in joining a wide variety of metals including aluminum, copper, stainless steel, titanium, all based on S-Bond alloys’ ability to directly wet and adhere to the metallic surface compounds. Using mechanical activation active solders such as S-Bond successfully join like and dissimilar metal combinations in a wide variety of applications, from heat sinks and sensors to medical/surgical devices. (more…)

Solar Panel Assembly

S-Bond has demonstrated the assembly (stringing) of photovoltaic (PV) solar panels bonding aluminum or copper buss bars using their active solders (S-Bond) in combination with thermosonic bonding. Thermosonic bonding is the simultaneous application of ultrasonic agitation, pressure and heat, normally applied using commercially available ultrasonic soldering irons. (more…)

Active Solder… What-Why-How

What is meant by “active solder”?  The term evolves from active brazing; I assume that does not really help you…. But it is true that active brazing was the key technology that led to the development of active solders. (more…)

Can S-Bond Soldered Joints be Coated ?

Many times our customers have to coat assemblies operations after aluminum bonding, graphite bonding, ceramic to metal bonding, etc; this can present certain challenges that one should be aware of since soldered joints. Unlike welded and many brazed joints, soldered joints utilize a significantly different filler metal. In the case of S-Bond solders, Sn-Ag is the common base filler that is used in aluminum bonding as well as copper, steel, stainless steel, refractory metals, and titanium and many other metals. As such, then the properties of the joint MUST be considered when coating. (more…)

Sapphire Window Sealing with S-Bond®

S-Bond® active solder enables the joining of sapphire to metals and provides an alternative to other sealing processes. S-Bond joining of sapphire/metal seals is proving to be a more robust and reworkable joining process while being simpler than many of the existing sapphire widow sealing processes, as this article presents. (more…)

Graphite / Carbon Joined to Metals with S-Bond®

S-Bond® active solders enable graphite bonding and the joining of other carbon or carbide based materials to each other and to most metals within the constraints of thermal expansion mismatch. S-Bond alloys have active elements such as titanium and cerium added to Sn-Ag, Sn-In-Ag, and Sn-Bi alloys to create a solder that can be reacted directly with the carbon surfaces prior to bonding using specialized S-Bond treatments prior to solder joining. Reliable joints have been made between graphite and carbon based materials with all metals including steel, stainless steels, titanium, nickel alloys, copper and aluminum alloys… (more…)

Aluminum Bonding with Active Solders

Active solder, S-Bond® alloys have been developed to bond to a range of metals, ceramics and composite materials without the need for fluxes of preplating. In particular, such active solder alloys have an affinity for joining aluminum to itself and other metals and ceramics. Aluminum soldering has gotten simpler with the emergence of such S-Bond® solders. Just melt the S-Bond filler metals, mechanically spread them on the surface via brushing, rubbing, or via ultrasonically activated spreaders and the alloys will wet, adhere and provide a base for bonding. In a subsequent step, when two molten pre-tinned S-Bond layers are pressed or slid together the S-Bond layers will activate a strong solder bond. (more…)

Mechanical Activation of Active Solders

Mechanical vs Chemical Fluxing During Solder Bonding

Flux is derived from Latin word fluxus meaning “flow.” In solder joining (also  aluminum soldering, graphite bonding, ceramic to metal brazing, etc.), a flux facilitates wetting by molten metals disrupting oxides on metal surfaces which interrupt the reaction/interaction of the molten solder metals with the underlying metal. Additionally, flux allows solder to flow easily on the working piece rather than forming beads as it would otherwise. (more…)