Currently, thermal film materials on the market fall into three main categories: natural graphite thermal films, artificial graphite thermal films, and nano‑carbon thermal films. The leading companies corresponding to these three categories are respectively GrafTech (USA), Panasonic (Japan), and SKC (South Korea).

Today, using 3D printing technology, GrafTech has invented a flexible circuit board with a flexible graphite substrate. By printing dielectric layers, conductive layers, and additional electronic components onto the flexible graphite matrix, this technology enables effective heat spreading from heat‑generating components without damaging adjacent parts. This plays a critical role in the development of smaller and thinner electronic devices such as smartphones, laptops, and flat‑panel televisions.

GrafTech was the first to address this challenge using compressed expanded graphite particle sheets, and pioneered the market for using this material in thermal management for electronic products. As more and more sophisticated electronic components emerge, sometimes these components generate relatively extreme temperatures during operation. Rising temperatures are a factor that must be avoided for improving processing speeds. These components include microprocessors and integrated circuits in electronic and electrical equipment, as well as high‑power optical devices and others.

Microprocessors, integrated circuits, and other complex electronic components typically operate effectively only within a certain threshold temperature range. When these components generate excessive heat during operation, it not only impairs their own performance but also reduces the overall system performance and reliability, and can even lead to system failures.

Thermal management has become an increasingly important factor in electronic product design. For example, lowering the operating temperature of typical silicon semiconductor devices leads to improved device reliability and extended product life. To maximise component life and reliability, controlling the device operating temperature is critical for designers.

Electronic components are usually mounted on circuit boards, also known as printed circuit boards (PCBs). As manufacturers continuously improve LCD display performance—for instance, by increasing display brightness—brighter LEDs are being utilised. As a result, the power consumption of LEDs increases significantly. The heat generated by the light source is detrimental to the operation of LCD displays. GrafTech’s flexible circuit board, produced by 3D printing conductive and dielectric layers onto a graphite substrate, can support light‑emitting diodes (LEDs). Both the heat‑dissipating section of the flexible circuit board with a graphite substrate and the light‑generating electronic component section are mounted on the component cross‑section.

GrafTech’s patent for this technology has been approved, which strengthens its capability to fabricate electronic devices on flexible materials that can be repeatedly twisted, stretched, or bent. Flexible and bendable electronics are poised to become a potential replacement for current printed circuit boards, with wide applications in foldable smartphones, various wearable devices, and automotive systems.

Coincidentally, at the beginning of 2017, a research team from Missouri University of Science and Technology successfully integrated flexible substrates with rigid conductive materials—different material properties—using direct aerosol printing technology, thereby combining conductive materials with flexible substrates. The elastic surfaces can be repeatedly twisted, stretched, and bent, enabling the production of bendable and stretchable electronic products with virtually no impact on their performance.