For high-end electronic products, the cooling structure is required to take up as little space as possible. the weight of the lighter the better, the more reliable performance, the better, air cooling heat sink obviously unable to meet this requirement, the designers gradually change from air cooling heat sink to water cooling plate, the solution involves what process can be used to process the custom cold plate to achieve the design intention.

Currently, there are three options:

1. Heat pipe heat dissipation;

2.The aluminum plate buried copper pipe to form a channel heat dissipation;

3. One cold plate, directly milling groove in the aluminum plate , cover plate welding to form a channel. The above three water cooling plate design schemes are analyzed as follows:

Heat pipe heat dissipation: basically is in the vacuum of the tube body form self-cooling cycle, but the scheme can not do large cold plate, at the same time inconvenient maintenance.

Buried pipe heat dissipation: the production cost of buried pipe heat dissipation is relatively low. The grooves are milling out in the aluminum plate and buried into the copper pipe according to the grooves to form a closed channel. The copper tubes and aluminum plates are filled with a gelatin.The scheme can meet the requirements of heat dissipation, but the disadvantage is that a large heat dissipation interval cannot be formed locally and it cannot meet the requirements of heat dissipation of some structural parts.

Integral cold plate: direct groove in the aluminum plate, plate welding forming channel, this needs to choose a kind of welding process on base plate and the cover plate sealing, preliminary selection of brazing process, brazing solder are the shortcomings of easy to loss, loss of solder may clog waterways, loss of the position of the solder will appear the phenomenon of not welded, led to the channel leakage.The yield is subject to manual proficiency, sense of responsibility, consistency of solder and control of the temperature in the furnace. The yield is about 80%.Too many uncertainty factors lead to the use of this process welding liquid cold plate is not reliable, especially on the important structure is rejected this process.

Because of the unreliability of the brazing process, the radar electronic heat sink has sought for the friction stir welding process to produce the aluminum cold plate. The friction stir welding process has shown its incomparable advantages in this product:

1. Welding under normal temperature without groove opening, filler, vacuum or gas protection;

2. Pleasant working environment, no noise, arc and radiation during welding;

3. High yield, numerical control operation, independent of manual proficiency;

4. High efficiency, with the same material and correct parameters, the yield is 100%.

The way of water cooling plate will replace the air cooling heat sink , and friction stir welding process will be favored by the structural designer with incomparable advantages!