Attachment Methods from Comair Rotron

The heat sink attachment method or technique is the single most important step in cooling electronic components. The effects of the heatsink attachment design flow through to the ultimate system performance or the ultimate manufacturing costs. The heat sink must not only be fastened to the electronic component, but also be secured to the PC board.

Attachment mechanisms can involve mechanical hardware, clips, epoxies and double sided tapes. In extreme cases, secondary support structures, know as retention mechanisms are added to the PC board for a reliable platform to support large format heat sinks.

Ultimately, engineering design specifications, physical space available, and thermal performance requirements determine the choice of attachment method. Another important design constraint the designer will face is maintaining the minimum force necessary for not only the thermal interface material selected, but also maintaining good system thermal contact over the range of anticipated environmental conditions.

A more efficient system design will result by upfront analysis of heat sink attachment method during the initial design phase. Three important considerations or decisions that need to be made when choosing a specific solution.

Familiarization with the different classifications of attachment methods
The target electronic component package type
The location of the primary anchor or weight bearing attachment point

The chart below represents the various generic classifications or approaches that ThermaFlo has provided and/or developed for our customers (both standard and custom) for attaching a heat sink. The chart summarizes the different manufacturing technologies available to produce an attachment method, the most common packages that require a heatsink and the most common anchor points for attachment. By clicking on the package type below, a list links you to heat sinks for those packages. Clicking on the Attachment Classification or anchor points give you a more detail explanation of the feature.

Attachment Classifications	Package Types	Attachment / Anchor Points
Clips	BGA's	Package
Spring (Saddle) Clips	CPU's	Socket
Wire Form Clips	DC/DC Converters	Heat Sink
Spring Loaded Pins	Metal Case Packages TO3, TO66	Printed Circuit Board
Integrated Heatsink Locking Mechanisms	Plastic Power Packages TO220, TO247	Printed Circuit Board
Double Sided Tapes	Surface Mount	Printed Circuit Board
Mechanical Hardware Screws / Nuts Solderable Studs & Standoffs Mounting Hardware	DC/DC Converters Plastic Power Packages TO220, TO247	Printed Circuit Board, Chassis
Epoxy	Surface Mount	Printed Circuit Board