Heatsink

Heatsink technology provides a special but very effective method for heat dissipation for components across circuit boards. Preferably thin circuit boards are laminated extensively onto an aluminium or copper heatsink using a heat transfer adhesive film. That way, the heat can be easily spread and transmitted to the heatsink.

The highlights of heatsink technology at a glance:

  • Heatsink applications provide optimised thermal management
  • Thin circuit board for good heat conduction and high cycle stability
  • Combination of vertical and horizontal heat dissipation
  • Vertical heat dissipation through thermal vias or a combination of microvia/buried vias
  • Horizontal heat dissipation through thermal dispersion in copper layers and/or heatsinks
  • Low thermal resistance
  • Various thicknesses possible
  • Individual shapes possible
  • Photosensitive solder resist, various surface finishes possible
  • Can be combined with all technologies

Particular attention is given to bubble-free bonding of the circuit board on the heatsink. Air inclusions between the circuit board and heatsink increase the thermal resistance of the application.

The use of heat transfer adhesives has an advantage over bonding using prepreg in that these acrylic adhesives remain elastic and flexible throughout their service life. Thanks to its slightly viscous properties, rough surfaces and height differences on heatsinks and circuit boards can be filled up well. Different expansion coefficients of circuit boards and heatsinks can be easily equalised.

Convection or condensation soldering processes can be used in the assembly of components onto circuit boards with glued heatsinks. The adhesives used are designed for short-term peak temperatures of 260 degrees and retain their properties after the soldering process. The maximum continuous operation temperature is 150 degrees. Thanks to very good heat dissipation, a longer preheating time and cooling time must be taken into account, as well as the time above the liquidus temperature. Ideal thermal management makes the soldering process more difficult!