Elephantech Unveils HDI Microvia Formation Process Using Copper Nanoparticle Ink

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Japanese deep-tech Elephantech announced successful development of an innovative process to form High-Density Interconnect (HDI) microvia leveraging the company’s copper nanoparticle ink, named “Cu Nano Direct Plating.”

Blind via formed using Elephantech’s copper nanoparticle ink (MSAP)

As AI servers and other advanced electronic systems evolve rapidly, demand for high-speed, high-density circuit boards is intensifying. However, the formation of blind via holes (BVH), which connect layers of the board, has become a major bottleneck. It is reported that 40% of HDI board defects are attributed to microvia cracks or plating voids [1], making improvement to via-formation process an urgent priority.

Conventional BVH formation via electroless copper plating presents several shortcomings:

• Plating defect risk: hydrogen gas generated as a byproduct during the reaction is difficult to evacuate from small-diameter vias, increasing the risk of voids
• Cost and resource risk: the process requires use of palladium, a precious metal, leading to cost volatility and supply chain risk
• Quality issues: in SAP processes, the required palladium removal step and its high possibility of leaving palladium residue compromise quality
• Environmental impact: the use of carcinogens such as formaldehyde, plus consumption of large volume of water carry a heavy sustainability burden

Graphite-based direct plating technology has also been commercialized as a palladium-free and outgas-free alternative. However, it still faces challenges such as high electrical resistance, as the seed layer is not composed of a copper layer.

In order to address these challenges, Elephantech has developed a novel direct plating process using its proprietary advanced copper nanoparticle ink.