Silver (Ag) bonding wire is red-hot as an alternative solution to copper and gold bonding wire. The high price of gold and the physical limitations of copper are two of the reasons the global market share of silver wire has jumped from around a one percent share in 2011 to an estimated seven percent in 2013 (source: Global Semiconductor Packaging Materials Outlook).
Now that silver wire has usurped some of the annual growth previously-held by bare copper wire and palladium-coated copper wire, an interesting question is how long this pace of rapid growth will be sustained.
Silver’s cost advantages will remain about the same – it’s cheaper than gold but enjoys the same production advantages such as ball bonding performance, soft FAB and excellent loop formation. Silver wire also will continue to offer an easier conversion process than copper as it can be implemented using legacy wire-bonding machinery.
So where will silver bonding wire make its advancements?
As a leading bonding wire manufacturer, Tanaka Denshi Kogyo is betting that silver is far from peaking. Too many commercial, industrial and residential markets have committed to the ecological and economical benefits of LED lighting technologies – already a strong niche for silver wire due to its high-reflectivity.
An LED typically is composed of a lead frame, a die and a fine wire bond, encapsulated through an epoxy body. An LED’s reliance on semiconductor assembly requires a different expertise than traditional lighting manufacturing, but also brings new demands to IC assembly.
For example, thermal issues are the reason for most reliability issues in high-power LED applications. Any inherent resistance in the silver bonding wire will tend to contribute to the thermal issue.
At Tanaka Denshi Kogyo, we recognized that the more impurities there are in the silver bonding wire, the greater its resistivity. The latest models of our silver bonding wire have a purity rating of over 97% and feature lower resistivity.
For the foreseeable future technical growth like this will help push this segment, making the future of silver bonding wire literally bright indeed.