INTERFACE MATERIALS Non Dielectric

1. Thermally Conductive Phase Change Films and Compounds
During warm-up over phase change temperature, phase change compounds start filling up surface-specific roughnesses and/or unevenesses and expel any air enclosures from micro structures. Depending on the type the filling up of the contact areas is further on improved by volumetric material expansion at increasing temperature. Convex and concave surface structures and stack up tolerances can widely be compensated by the use of these materials. Their thixotropic nature prevents run-out. The thicknesses are characterized by high process reliability what among others makes these films ideal for replacing thermal greases.

Types:

  • Aluminum films with phase change coating
  • Phase change films
  • Pre-applicable printable or dispensable compounds


Coating of electrically non-insulating films such as aluminum with phase change compounds or use of phase change films softening from certain temperatures leads to minimizing thermal contact resistances at low pressures. Thus the total thermal resistances will be reduced.
Drying types of compounds can be printed either on heat sinks or heat sources by stencil or screen printing or dispensed resulting in a pre-applied and dry-to-the-touch interface solution which is ready to be assembled.

Download Standard Configurations

Properties and advantages in brief:

  • Extremely low thermal resistances down to and below 0.01 °C-inch2/W
  • Silicon-free
  • Easy pre-assembly
  • Process reliable coating thicknesses
  • Pre-applied and dry-to-the-touch printable or dispensable types
  • Ideal replacement of messy thermal grease


Available as:

  • Sheet or roll
  • Kiss cut parts on roll
  • Die cut parts
  • Without or with adhesiveness to cover all over or with partial adhesiveness
  • Different thicknesses of phase change coating
  • Dispensable and printable compounds in cartridges

 

2. Highly Thermally Conductive Gap Filler 
Non dielectric highly thermally conductive gap fillers reach extreme thermal conductivities from 10 W/mK up to 50 W/mK. Their softness allows for an excellent thermal contact, surface compliance and compensation of big mechanic tolerances.

HALA Thermal Navigator

Properties and advantages in brief:

  • Thermal conductivities from 10 W/mK up to 50 W/mK
  • Thermal resistances of less than 0.05 ∞C-inch≤/W
  • Thicknesses of 0.2 up to 2.0 mm
  • Excellent surface compliance and thermal contact by material softness
  • Maximum compensation of mechanic tolerances 


Available as:

  • Sheets
  • Die cut parts
  • Kiss cut parts on sheet


Thermal link of:

  • CPUs to heat sinks
  • Power modules to heat sinks 
  • Semiconductors to heat plates


For use in:

  • Power inverters
  • Laptops
  • Automotive power supplies 
  • Industrial PCs

 

3. Thermally Conductive Graphite Foils

3.1. Pyrolytic Gaphite Foils

Pyrolytic graphite foils consist of pure artificial graphite. Due to their flake-like shape they show anisotropic thermal conductivities in-plane (x-y-plane) and vertically (z-direction). Heat is then transferred away from hot-spots in a directed way and spread within the interface material. Its flexibility allows for a good compliance to the contact surfaces, thus minimizing the thermal contact resistance. Its low density compared to copper or aluminum makes it ideal for applications where low weight is required. The very high temperature resistance allows for the use in extreme hot environments. The foils can easily and flexibly be bent by 180°C without damage or cracks.

HALA Thermal Navigator

Properties and advantages in brief:

  • Thermal conductivities up to 1,950 W/mK in-plane and 25 W/mK in through z-direction
  • Heat spreading from hot-spots
  • Thermal resistances of less than 0.03 °C-inch²/W
  • Low thermal contact resistance through good surface compliance 
  • Very low weight
  • Silicone-free
  • Extreme temperature range up to 400 °C
  • No dry-up, migrating, run out or pump out 
  • EMI-shielding through high electrical conductivity
  • 180 °C bendable without damage or cracks

Available as:

  • Sheet 
  • Die cut parts  
  • Without or with tackiness
  • With or without dielectric films (PEEK, PI, PET)


Thermal link of:

  • CPUs
  • Laser diodes
  • TEC assemblies
  • High flux LEDs

For use in:

  • High-end computers
  • Analyzers
  • Photonics
  • LED arrays
  • Medical

3.2. Natural Graphite Foils

Graphite foils consist of more than 98% pure natural graphite. Due to their flake-like shape they show anisotropic thermal conductivities in-plane (x-y-plane) and vertically (z-direction). Heat is then transferred away from hot-spots in a directed way and spread within the interface material. Its softness allows for a good compliance to the contact surfaces, thus minimizing the thermal contact resistance. Its low density compared to copper (15%) or aluminum (50%) makes it ideal for applications where low weight is required. The very high temperature resistance allows for the use in extreme hot environments. 

 HALA Thermal Navigator

Properties and advantages in brief:

  • Thermal conductivities up to 200 W/mK in-plane and 5 W/mK in through z-direction
  • Heat spreading from hot-spots
  • Thermal resistances of less than 0.07 °C-inch²/W
  • Low thermal contact resistance through good surface compliance 
  • Very low weight
  • Silicone-free
  • Very high temperature range up to and over 300 °C
  • No dry-up, migrating, run out or pump out 
  • EMI-shielding through high electrical conductivity 

 Available as:

  • Sheet or roll 
  • Kiss cut parts on roll
  • Die cut parts  
  • Without or with adhesiveness to cover all over or with partial adhesiveness

Thermal link of:

  • CPUs to heat sinks
  • Power modules to heat sinks 
  • Semiconductors to heat plates

For use in:

  • Power inverters
  • Laptops
  • Automotive power supplies 
  • Industrial PCs


4. Thermally Conductive PSA Tapes
Adhesive PSA tapes are based on pressure sensitive high bonding acrylate adhesives showing non-dielectric but grounding properties. Through the thermally conductive adhesive the thermal contact is highly improved, thus minimizing the total resistance, even at low pressures. Materials with different expansion coefficients can easily be bonded, thus giving a reliable thermal link.

Convex and concave surface structures stack up tolerances can widely be compensated by the use of these materials.

Thermally conductive adhesive films work well for realizing an easy effective and cost-efficient thermal link of electrically insulated electronic packages to heat sinks. Above all they are used in applications having little space only and where their permitted weight is very limited. Using screws, springs, clips as mechanic fasteners, thus becomes superfluous.

Properties and advantages in brief:

  • Acrylate - silicone-free
  • Very low thermal resistances of less than 0.3 °C-inch²/W through excellent thermal contacts
  • Reliable strong adherence on uneven or hardly machineable surfaces
  • No need of mechanic fasteners e.g. screws, springs, clips
  • Very good pre-assembly
  • No migration – compared to thermal greases
  • Neither mixing of components nor curing processes
  • Solvent-free and resistant
  • No impurities
  • Reliably constant thickness


Available as:

  • Sheet or roll
  • Kiss cut parts on roll
  • Die cut parts on roll
  • Bulk die cut parts


Some application examples:

Thermal link of:

  • LEDs
  • Heat sinks to CPUs
  • Temperature sensors to the point of measurement
  • Through-hole vias to cooling plates


For use in:

  • LED lights and LED arrays
  • Automotive engine management systems
  • PCs
  • Telecom appliances

 

5. Thermally Conductive Adhesives

The thermally conductive adhesive systems are based on silicone or acrylates. There are both room temperature vulcanizing one-part or two-part systems and rapidly curing one-part systems. The thermal gradient is minimised through the excellent thermal contact due to their high bonding properties as well as thermal conductivities up to 2.8 W/mK. At the same time using screws, springs, clips as mechanic fasteners, becomes superfluous and the system remains at zero pressure. Mechanic tolerances can be compensated at no pressure.

Thermally conductive adhesives work well for realizing an easy effective and cost-efficient thermal bonding of PCB, LEDs, CPUs, ICs or other electronic packages to heat sinks. Above all they are used in applications having little space only and where their permitted weight is very limited. Materials with different expansion coefficients can easily be bonded, thus giving a reliable thermal link.

Properties and advantages in brief: 

  • Very low thermal resistances through excellent thermal contacts 
  • Reliable strong adherence on uneven or hardly machineable surfaces
  • Excellent compensation of mechanic tolerances
  • No need of mechanic fasteners e.g. screws, springs, clips


Available as:

  • Modified acrylate or silicone
  • One or two-part systems
  • RTV or heat curing
  • Addition or condensation curing (moisture)
  • Available in cartridges or pails

 

For further information please see our material-specific data sheets 

We select the right material from our broad product portfolio and offer customized design-in 

Please contact us as your development partner.