LG Innotek innovates by replacing solder balls with Copper Posts, for thinner smartphones

LG Innotek has proposed a new way to make smartphones thinner than ever before, removing solder balls that attach chip substrates to motherboards, replacing the solder balls with Copper Posts.

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The new packaging method developed by LG Innotek sees the placement of copper columns on the substrate before solder balls are applied on top, rather than bonding the balls directly to the surface.

The resulting structure reduces the spacing between solder balls by approximately 20% compared to traditional layouts, while keeping the same electrical performance. LG says that its new method would provide smartphone designers with more flexibility in making slimmer smartphones, while increasing available space for things like bigger batteries.

Copper Posts could potentially enable denser packaging, which is perfect for high-performance interfaces, which will help with new features and performance of next-gen smartphones. The high melting point of copper ensures that the columns maintain their shape in high-temperature manufacturing steps, enabling tighter integration that was previously impractical because of the risk associated with solder balls merging during the soldering process.

Copper conducts heat more than 7x better than typical soldering materials, allowing excess heat from semiconductor packages to dissipate faster, helping maintain stable performance and minimizing issues like signal degradation caused by overheating.

LG Innotek began its work on Copper Post technology back in 2021, using a digital twin-based 3D simulation to boost development and improve design precision. LG Innotek has secured around 40 patents related to its new Copper Post technology, with plans to use the new technology on RF-SiP substrates (modems, power amplifiers, FRMs, filters combined into a single package) and FC-CSP (Flip Chip-Chip Scale Package for application processors) substrates for smartphones and wearables.

Moon Hyuk-soo, chief executive of LG Innotek, said: "This technology is not simply about supplying components - it came from deep consideration of how to support our customers' success. With this innovation, we will change the paradigm in the substrate industry and continue to create differentiated customer value".