Resin materials for improved thermal management in electronic devices
Electrical and Electronic Components

Resin materials for improved thermal management in electronic devices

The importance of thermal management in electronic devices

Thermal management in electronic devices is a crucial consideration with direct consequences for device performance and lifetime. In recent years, the trends toward increasing device functionality and shrinking device footprints have caused thermal emissions to increase, creating a need for efficient cooling techniques. 

Today, the problem of thermal management has become a key technical challenge for a broad spectrum of components across a wide range of applications, including base stations for information communication networks, power-conversion systems (PCSs) for solar generators, inverters, motors, and more. In particular, rapid recent growth in the fields of artificial intelligence (AI) and internet-of-things (IoT) has spurred a proliferation of high-density systems featuring large numbers of components operating in close proximity—and placing increasingly stringent demands on heat-management systems.

These developments have made thermal management an essential domain of modern technology, with immediate ramifications for the reliability of electronic devices.

For thermal management in electronic devices, Asahi Kasei recommends SunForce™ foams: flame-retardant, heat-resistant engineering plastics boasting excellent thermal insulation and extensive shape flexibility.


Engineering-plastic foams for improved thermal management in electronic devices:
Sunforce

What is SunForce™?

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.

What is SunForce™?

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

 

Material Thermal conductivity
(W/m・K)
Material Thermal conductivity
(W/m・K)
Material Thermal conductivity
(W/m・K)
Carbon nanotubes 5500 LCP (Liquid Crystal Polymer) 0.56 SunForce™ (x5) 0.041
Diamond 2000 FRP (Fiber Reinforced Plastic) 0.26 Cellulose fiber 0.040
Copper 370 PPS (Polyphenylene Sulfide) 0.26 Rockwool 0.038
Aluminum 200 Polycarbonate 0.19 SunForce™ (x7) 0.038
Graphite 120 ABS 0.19 Glass wool 32K 0.036
Iron 80 Polyvinylchloride (PVC) 0.17 Melamine foam 0.035
Carbon-copper 41 Plywood 0.16 SunForce™ (x10) 0.034
Alumina 32 Particle board 0.15 Extruded polystyrene foam (Type 3) 0.028
Stainless steel 16 Modified PPE 0.15 Hard urethane foam (Type 1 #1) 0.024
Carbon fiber-reinforced plastic 4.7 Polystyrene 0.15 Air 0.022
Zirconia 3.0 Cypress wood 0.095 Silica aerogel 0.017
Concrete 1.6 Cedar wood 0.087 Carbon dioxide 0.015
Glass 1.0 Cork 0.043 Vacuum insulation material 0.002
Water 0.58
Thermal insulation of SunForce™ (comparison of a range of materials, room temperature reference values)

 

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

Sample application 1: 
SunForce™ heat shields for heat-emitting components

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).

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

Original system design (left) and improved system design (right) featuring SunForce™ heat shields for thermal insulation of non-heat-emitting components.
Original system design (left) and improved system design (right) featuring SunForce™ heat shields for thermal insulation of non-heat-emitting components.

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.

Results of thermal-analysis simulations before and after adding SunForce™ (BE, 10×, t = 10 mm) heat shields
Results of thermal-analysis simulations before and after adding SunForce™ (BE, 10×, t = 10 mm) heat shields

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.

Sample application 2: 
SunForce™ thermally-isolating ducts

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.

Regions of obstructed airflow inside an electronic device
Regions of obstructed airflow inside an electronic device

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.

Schematic depictions of the original system design (left) and the improved design featuring thermally-isolating SunForce™ ducts (right)
Schematic depictions of the original system design (left) and the improved design featuring thermally-isolating SunForce™ ducts (right)

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.

Simulated airflows within the PCS unit before (left) and after (right) the addition of SunForce™ ducts
Simulated airflows within the PCS unit before (left) and after (right) the addition of SunForce™ ducts

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

Simulated temperature distributions within the PCS unit before (left) and after (right) the addition of SunForce™ ducts
Simulated temperature distributions within the PCS unit before (left) and after (right) the addition of SunForce™ ducts

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.

Contact us for more information.

For more information or to request a sample, please contact us using the form on this site.

Other Solutions
「Electrical and electronic」