Nextreme Copper Pillar Bump for Flip Chip Packaging

Nextreme has integrated cooling and power generation into the widely accepted copper pillar bumping process used in high-volume electronic packaging. The innovation in flip chip process technology addresses two of the most serious issues in electronics today – thermal and power management constraints. Nextreme’s approach uses proven, fully scalable technology to deliver new, enabling functionality in flip chip applications.

Heat and power issues are gating progress – especially in high-end, flip-chipped devices. At the semiconductor chip, package and system level, higher densities, more features, higher speeds and miniaturization are all contributing to more heat and higher power densities emanating from our electronics. There is often a misconception that system level cooling using heat sinks, fans, water cooling and even refrigeration, can ultimately solve these problems. While this is true technically, the power required to achieve the system level cooling solution is in of itself a fundamental limitation to achieving desired results.

Until now, copper pillar bumps have been used for the electrical and mechanical connection between the electronic device – such as a microprocessor – and the outside world. Nextreme’s breakthrough creates a thermally active copper pillar bump, adding two fundamentally new functionalities that have not otherwise been implemented in existing electronic packaging. When electrical current is passed through Nextreme’s thermal bump, one side cools rapidly relative to the other. Alternatively, when heat passes through the thermal bump, the bump actually generates power.

Nextreme added this functionality by incorporating a thin film of proprietary nano-material into a proven and widely available manufacturing technique called solder bumping. Most recently Nextreme demonstrated its innovation in a copper pillar bump – a high-volume manufacturing approach used by Intel, Amkor and others to connect microprocessors and other advanced electronics devices to various surfaces using a process referred to as “flip chip” packaging.

Nextreme is implementing the technology in conventional approaches for existing customers for thermal management in lasers and sensors, to cool high temperature electronics and to trickle charge miniature batteries. In the future, customers will be able to use standard electronic design tools to integrate Nextreme’s thermal bump using the integrated circuit design process. This will enable customers to place cooling or energy harvesting functionality exactly where it is needed on the electronic chip. This will be done in the same manner that capacitors, resistors, transistors and electrical interconnects are designed into electronics today. Once designed in, the thermal bump will be implemented as part of the standard flip chip solder bumping process – a seamless part of the overall manufacturing sequence. This represents a true paradigm shift in thermal and power management for the entire electronics industry.

Potential flip chip applications for Nextreme’s thermal bump include microprocessors, display drivers, chip sets, RF devices, medical devices, watches, smartcards and analog/mixed signal devices. Manufacturing of discrete thermal management devices from Nextreme will be supported with production at the Company’s US facility in North Carolina; die level integration will largely be outsourced off shore; and wafer level processing will be licensed to merchant and captive providers of wafer-level flip chip processes.

More info: Nextreme