Technology > Pin Fin Design

Pin fin heat sinks are considered to be among the most powerful heat sink designs available today
Pin fin heat sinks provide very low thermal resistance values per given space and low pressure drop
The cooling capabilities of pin fins stem from the round geometry of the pins, the omnidirectional pin configuration, and the use of highly conductive materials
The smooth round pins reduce resistance to incoming air streams and enhance air turbulence between the pins
The omnidirectional structure maximizes the entrance of fresh air into the pin array and at the same time allows the hot air to exhaust from the pin array in every possible direction
The use of highly conductive materials further reduces the thermal resistance of the heat sinks
Cool Innovations has further enhanced the performance of pin fin heat sinks via the introduction of the splayed and flared pin fin designs
Their unique structure allows them to offer lower thermal resistance values and lower pressure drop per given space

Flared pin fin heat sinks offer a revolutionary alternative for natural convection cooling (0 LFM)
Flared pin fin produce more cooling power in the natural convection then most available heat sink designs
The cooling premium stems from a unique structural characteristic they possess: a combination of substantial surface area and a sparsely configured pin area
As a result of the wide spacing between the pins, flared pin fins feature very low friction between the air and the surface area and as a result the chimney effect is accelerated
Friction is further reduced due to the naturally sparse pin configuration and the round nature of the pins
Flared pin fin heat sinks are a great fit for HB LEDs and other applications that operate in natural convection
Flared pin fin heat sinks range from a footprint of 1.0" x 1.0" to a footprint of 5.0" x 5.0" and from a height of 0.7" to a height of 2.0" For more

Splayed pin fin heat sinks offer a highly efficient omnidirectional cooling alternative for limited and moderate airspeed environments (0-400 LFM)
Unlike standard pin fins that possess a vertical pin array, splayed pin fin heat sinks feature pins that are bent outward gradually
By better utilizing available application space, splayed pin fins are able to produce a previously unattainable combination of a large surface area and a sparse configuration
As a result, the resistance to incoming airstreams is reduced significantly and the surface area of the heat sink is exposed to substantially stronger airstreams and thus the cooling power these heat sinks generate is up to 30 percent greater then traditional pin fin heat sinks
An additional product of the splayed design is a substantial reduction in pressure drop
The impact of increased pin spacing on heat sink performance is magnified at lower air speeds because weak airstreams have less power to penetrate the array of pins.
Due to the combination of high cooling power and low pressure drop splayed pin fins are ideal for heavily populated boards in which the management of air flows along the PCB is critical
Splayed pin fin heat sinks are available in copper and aluminum and range from a footprint of 0.54" x 0.54" to a footprint of 2.05" x 2.05" and from a height of 0.3" to a height of 1.1" For more

The Cold Forging process is used in the manufacturing of the majority of Cool Innovations heat sinks
The process ensures that no air bubbles, cavities or any other impurities are trapped within the material
The cold forging process allows for the use of highly conductive copper and aluminum alloys
Aluminum pin fin heat sinks are forged from pure aluminum (AL1100)
The thermal conductivity of AL 1100 is 1510 btu/in ft2 hr of. (~50% higher than AL 380, a common cast alloy)
Copper pin fin heat sinks are forged from pure copper (CDA 110)
The thermal conductivity of CDA 110 is 2712 btu/in ft2 hr of. (~100% higher than AL 380, a common cast alloy)

The lapping process significantly improves the flatness and the surface finish of the base of the heat sink, when compared to conventional base finishing processes
The contact resistance between the heat sink and the device is reduced significantly following the completion of the lapping process
Cool Innovations heat sinks meet a flatness of better than 0.001 inch/inch
Surface Finish is 16 RMS or better

Cool Innovations Receives Product of the Year Award for Splayed Pin Fin Design

EEPN article outlines the steps required to properly select a pin fin heat sink