| Thermal tape |
- Generally it is easy to attach and is
inexpensive
- Lowest cost approach for aluminum heat sink
attachment
- No additional space required on the PCB
|
- The surfaces of the heat sink and the chip must
be very clean to allow the tape to bond correctly
- Because of the small contact area, the tape
might not provide sufficient bond strength
- Tape is a moderate to low thermal conductor that
could affect the thermal performance
|
| Thermally conductive adhesive or glue |
- Outstanding mechanical adhesion
- Somewhat inexpensive, costs a little more than
tape
- No additional space required on the PCB
|
- Adhesive application process is challenging and
it is difficult to control the amount of adhesive to use.
- Difficult to rework
- Because of the small contact area, the adhesive
might not provide sufficient bond strength
|
| Wire form Z-clips |
- It provides a strong and secure mechanical
attachment. In environments that require shock and vibration
testing, this type of strong mechanical attachment is
necessary.
- Easy to apply and remove. Does not cause the
semiconductors to be destroyed (epoxy and occasionally tape can
destroy the device).
- It applies a preload onto the thermal interface
material (TIM). Preloads actually improve thermal
performance.
|
- Requires additional space on the PCB for anchor
locations
|
| Plastic clip-ons |
- Suitable for designs where space on the PCB is
limited
- Easy to rework by allowing heat sinks to be
easily removed and reapplied without damaging the PCB board
- Can provide a strong enough mechanical
attachment to pass shock and vibration test
|
- Needs a keep out area around the silicon devices
to use the clip
- Caution is required when installing or removing
clip-ons because localized stress can damage the solder balls or
chip substrate
|
| Threaded stand-offs (PEMs) and compression
springs |
- Provides stable attachments to heat source and
transfers load to the PCB, backing plate, or chassis
- Suitable for high mass heat sinks
- Allows for tight control over mounting force and
load placed on chip and solder balls
|
- Holes are required in the PCB taking valuable
space that can be used for trace lines
- Tends to be expensive, especially because holes
need to be drilled or predrilled onto the PCB board to use
stand-offs
|
| Push-pins and compression springs |
- Provides a stable attachment to a heat source
and transfers load to the PCB
- Allows for tight control over mounting force and
load placed on chip and solder balls
|
- Requires additional space on the PCB for
push-pin locations
|