Resin materials for improved thermal management in electronic devices

SunForce™ products are foam beads made from XYRON™ modified PPE resins that combine the excellent physical properties of modified PPE resins—including heat resistance, dimensional stability, and low water absorption—with the light weight and good excipient properties (shape flexibility) of beaded foams.

Moreover, the combination of flame retardance with heat resistance allows SunForce™ foams to meet the stringent UL94 V-0 flammability standard even in the form of a beaded-foam material. 

Because SunForce™ products are produced by in-mold foaming, they are also ideally suited for mass production.

In addition, the independent-bubble structure of  SunForce™ foams makes these materials excellent thermal insulators.

In what follows we present two illustrative applications exploiting the unique properties of SunForce™ foams to improve thermal management in electronic devices.

SunForce™ is well-suited for mass production of thin-walled, complex-shaped insulation materials due to its high heat resistance and flame retardancy (certified to UL94 V-0 standards) derived from the material. It is formed by in-mold foaming using small-diameter beads as raw material. This allows for the mass production of insulation materials that fit the complex shapes of components.

For applying insulation to complex components, glass wool or urethane foam is commonly hand-applied by workers. However, using SunForce™, not only enhances heat management efficiency through high thermal insulation but also contributes to condensation prevention, reduction of the number of parts (saving labor and costs), and improved productivity and assembly precision (ensuring stable product quality) during assembly.

These characteristics allow SunForce™ to be applied across a wide range of fields that require high performance and high safety, such as cooling components for automobiles, cooling parts for 5G/6G communication devices and solar power conditioners, water cooling components for data centers and AI servers, engine oil separators, and air conditioning ducts.

SunForce™ is also suitable for heat management in high temperature and high humidity environments such as washing and drying machines.

In a simulation of application to a drum-type washer-dryer, it was found that the high insulation properties of this product help maintain the temperature inside the drum during drying operation, reducing energy loss, as shown in the figure below.

SunForce™​ ​stable mechanical strength and dimensional stability even in high temperature and high humidity environments, making it possible to mass-produce high-performance insulation materials. In addition, its high flame resistance (UL94 V-0) makes it suitable for placement around electrical connection points in home appliances and electronic devices.

Our first example uses SunForce™ heat shields to achieve thermal insulation in an electronic circuit board with highly heat-emitting components (such as might be found in a PCS unit in a solar-power generator).

SunForce™ foams make them ideal materials for heat shields to isolate heat-emitting regions from non-heat-emitting regions of electronic circuit boards.The excellent thermal insulation, extensive shape flexibility, flame retardance, and heat resistance of 

The figures below show the temperature distribution inside an electronic device, computed using a thermal-analysis simulation model, before and after the addition of thermally-isolating SunForce™  heat shields to isolate highly heat-emitting components from non-heat-emitting components. These results demonstrate how SunForce™ thermal-management solutions can achieve significant reductions in internal device temperatures.

This example demonstrates how heat shields made from SunForce™ foams can simplify the miniaturization of electronic devices by reducing operating temperature, preventing component degradation, and allowing greater flexibility in component layout.

Our second example involves the installation of thermally-isolating SunForce™ ducts on an electronic circuit board equipped with highly heat-emitting components. This complements the heat-shield example discussed above by presenting an alternative way in which the unique properties of SunForce™ foams can be exploited to improve thermal-management performance in electronic devices.

Differences in the operating temperatures of electronic components give rise to convection airflows inside electronic devices. In some cases, various factors—such as the layout of components or the temperature distribution within the device—may conspire to obstruct the flow of air through particular device regions, degrading the performance of cooling mechanisms and causing component temperatures to rise.

The problem of obstructed airflow arises in the specific system considered in this example: a solar-cell PCS unit equipped with an internal cooling fan, depicted schematically at the left in the figure below. To alleviate this problem, we improved the design by installing thermally-isolating SunForce™ ducts around the fan unit, as shown at the right below.

The streamline diagrams below show simulated airflows through the electronic device before and after the addition of SunForce™ ducts. Comparing these plots, we see that the ducts create new pathways for air to flow through the device, ensuring smoothly-controlled airflows at all stages from intake to exhaust. The improvement in airflow quality is particularly significant in the vicinity of heat-emitting components.

The simulated temperature distributions are plotted below: The controlled airflow enabled by the presence of the ducts yields significant reductions in component temperatures.

This example demonstrates how thermally-isolating ducts made from SunForce™ foams can improve airflow control in electronic devices, thereby reducing component temperatures, preventing component degradation, and allowing greater flexibility in component layout.

Asahi Kasei 's modified PPE resin XYRON™ is a general term for polymer alloys that combine polyphenylene ether (PPE) with other resins.

XYRON™ has several excellent properties. In addition to its high heat resistance, it also has excellent flame resistance, dimensional stability, and water resistance, as well as low specific gravity. Furthermore, by adding PPE to it while taking advantage of the properties of other resins, it is a polymer alloy that aims for a synergistic effect with the properties of PPE.

We propose XYRON™ G703Z, a halogen-free, TPP*-free modified PPE resin that combines thin-wall flame resistance with high strength, as a material for high-speed fan motors used in server thermal management.
* TPP: Triphenyl phosphate

PPE resin is particularly light among engineering plastics and reduces the centrifugal force generated in the fan, which enables the fan to rotate at a higher speed, increasing the volume of air and the amount of heat exhausted.

In addition, with a glass transition temperature of approximately 220°C, it has high heat resistance and maintains excellent physical properties even at high temperatures, and can withstand the environmental temperature rises of high-performance servers, which can sometimes reach 90°C. Furthermore, XYRON™ G703Z (PS/PPE alloy, GF30%) is halogen-free, TPP-free, and thin-walled and flame flame resistance (UL94 V-0/0.75mm), which was previously difficult to achieve, making it an ideal material for high-speed fan motors.

Asahi Kasei has manufactured model sample fan motor durability test equipment and is conducting practical performance evaluations of materials.

We 3D scan commercially available fan motors, create injection molding dies from the CAD data, mold resin model samples, and conduct comparative evaluations of materials. Because the temperature of these model samples can be controlled in an oven, we can conduct durability tests at temperatures and rotation speeds close to the actual usage environment.

The download materials provide detailed data on durability tests, so please take a look.