Note: Descriptions are shown in the official language in which they were submitted.
CA 02374008 2001-11-14
A COOLING DEVICE FOR ELECTRONIC COMPONENTS
Description:
The present invention relates to a cooling device for electronic components,
in
particular for cooling microprocessors, which has at least one passive thermo-
conducting cooling elemenf.
io A wide variety of electronic component cooling devices of this type are
known in the
prior art. These especially comprise passive thermo-conducting cooling
elements, in
particular made of aluminum, which are mounted on the surfaces of said
electronic
components, thus effectively contacting them. The cooling elements are
attached
thereto by means of adhesive or special supports. Usually, there is also an
additional
is active cooling element in the form of a fan, which is either positioned on
said passive
cooling elements or integrated within said passive cooling elements.
The prior art cooling systems are all based on the principle of heat transfer
by
evaporation, condensation, convection and dissipation, or they are
characterized by
2o different material combinations and surface structures of different thermo-
conducting
capacities andlor thermal resistances.
A disadvantage of the prior art cooling devices, however, is that in view of
the ever
more powerful electronic components, in particular due to the higher and
higher
2s microprocessor clock rates, the development of heat also increases
strongly. Since
such electronic components will only function properly in a certain
temperature range,
however, and too high temperatures will cause them to either become
inoperative or
lose considerable power, ever increasing demands are also made on the
respective
cooling devices. The above mentioned coolers of the prior art are no longer
capable
30 of achieving the desired and required degree of cooling.
CA 02374008 2001-11-14
2
Therefore, it is the object of the present invention to provide a cooling
device for
electronic components, in particular for cooling microprocessors, which has at
least
one passive thermo-conducting cooling element, which device will ensure
sufficient
cooling of the electronic components even in case of a strong heat build-up.
s
This object is accomplished by a generic cooling device having the features of
claim
1.
Advantageous embodiments are described in the subclaims.
to
An inventive cooling device for electronic components includes at least one
passive
thermo-conducting cooling element, with at least part of said passive cooling
element
contacting at least one heat transfer medium which is in a solid aggregation
state.
Said heat transfer medium in this case is a phase change material (PCM) which
has a
is much higher heat capacity than water, for example. Moreover, said heat
transfer
medium has been designed as a latent heat accumulator to store the amount of
heat
generated by the load on the electronic component that can no longer be
absorbed
and carried off by said passive cooling element, at the same time maintaining
its solid
state of aggregation, and release said heat again at a time when there is a
lower load
20 on the electronic component. This will ensure that electronic components,
in particular
microprocessors, will be sufficiently cooled even if there is a high load and
a
corresponding high heat build-up. At the same time, the heat transfer medium
is
capable of absorbing temporarily occurring additional amounts of heat and of
releasing them again once the load is back to normal, i.e. the electronic
component
2s develops a normal amount of heat again. Peak thermal loads are thus avoided
which
usually clearly diminish the power of the electronic component and especially
that of a
microprocessor when conventional cooling devices are used. Consequently, the
inventive cooling device also allows an increase in power of the cooled
components.
Avoiding damaging peak heat loads will furthermore increase the working life
and the
30 operativeness of the electronic components cooled by means of the cooling
device of
the invention. Since the phase change material used as a heat transfer medium
will
retain its solid state of aggregation also during heat absorption, there will
CA 02374008 2001-11-14
3
advantageously not be any problems due to an expansion of the phase change
material, as opposed to what is always the case with known materials.
In an advantageous embodiment of the cooling device of the invention, the heat
s transfer medium consists of salts or salt mixtures enriched with organic
substances
as well as of substances in the form of fine metallic powders for improving
the
thermo-conducting capacity. Usually, the organic ingredient of the heat
transfer
medium is paraffin. A heat transfer medium of this kind will also retain its
solid state
of aggregation during heat absorption, and may thus be mounted in the form of
a
io tablet or pellet and/or as a solid body within andlor on said cooling
element. This will
allow said cooling device to be manufactured economically, on the one hand,
and, on
the other hand, it will ensure that it can be kept small in size. Moreover, it
is possible
according to the invention to individually adjust the heat transfer medium to
the
required operational temperatures for cooling the electronic components. Such
is adjustment is done by varying the kind and amount of the ingredients of the
heat
transfer medium. In particular, it is also possible to adjust the amount of
heat to be
buffered by the heat transfer medium. Moreover, another advantage of said heat
transfer medium is that it is non-toxic as well as recyclable.
2o In an advantageous embodiment of the cooling device of the invention, the
passive
cooling element includes at least one active cooling element, in particular a
fan. This
will advantageously ensure a further increase of the cooling power of the
cooling
device.
2s In yet another advantageous embodiment of the cooling device of the
invention, the
heat transfer medium is accommodated in a container made of thermo-conducting
material, said container contacting said passive cooling element. Providing
said heat
transfer medium within a container will allow easy replacement of the
individual heat
transfer elements mounted within or on said passive cooling element.
In yet another advantageous embodiment of the cooling device of the invention,
a
thermo-conducting foil is provided between a contact surface of said passive
cooling
CA 02374008 2001-11-14
4
element and a corresponding contact surface of said electronic component. This
measure will ensure that the total cooling power achieved by means of said
cooling
device is increased further by an optimized heat transfer from the electronic
component to the passive cooling element.
The invention furthermore relates to a processor with a processor socket and
at least
one cooling device mounted on said processor, which cooling device includes at
least
one passive thermo-conducting cooling element, with at least part of said
passive
cooling element contacting at least one heat transfer medium which is in a
solid state
to of aggregation. In this case, the heat transfer medium is a phase change
material
(PCM) which has a much higher heat absorption capacity than water for example.
Moreover, said heat transfer medium has been designed as a latent heat
accumulator
so as to store the amount of heat generated by the load on the processor that
can no
longer be absorbed and carried off by the passive cooling element, at the same
time
is retaining its solid state of aggregation, and to release said heat again at
a time when
there is a smaller load on the processor.
The invention furthermore relates to the use of a heat transfer medium, which
is in a
solid state of aggregation, for cooling microprocessors, said heat transfer
medium
2o being a phase change material (PCM) that has a much higher heat absorption
capacity than water and has been designed as a latent heat accumulator. The
heat
transfer medium will store the amount of heat generated by the load on the
microprocessor, at the same time retaining its solid state of aggregation, and
release
said heat again at a time when the load on the microprocessor is smaller.
Further details, features and advantages of the present invention may be
gathered
from an embodiment shown in the attached drawings, of which:
Fig. 1 is a schematic sectional view of a cooling device of the invention;
Fig. 2 is a schematic top view of the cooling device of the invention as shown
in Fig.
1; and
CA 02374008 2001-11-14
Fig. 3 is a schematic lateral view of the cooling device of the invention as
shown in
Fig. 1.
s Figure 1 is a sectional view of a cooling device 10 for cooling electronic
components,
in particular for cooling microprocessors. Said cooling device 10 comprises a
passive
thermo-conducting cooling element 12, which cooling element 12 consists of a
plurality of cooling ribs or fins 14. Said cooling ribs or fins 14 are mounted
on a
bottom element 16 of said cooling element 12. On the side opposing said
cooling ribs
io or fins 14, said bottom element 16 exhibits a contact surface 18 which
contacts the
electronic component intended to be cooled.
The passive cooling element 12 is made of aluminum or an aluminum alloy, and
is
usually a single piece. It can be seen in this drawing that plural heat
transfer media
is 20 are provided between the cooling ribs or fins 14 within said cooling
element 12.
Said heat transfer media 20 are in a solid state of aggregation and in thermo-
conducting contact with said cooling ribs or fins 14 and said bottom element
16 or
said cooling element 12, resp. In this case, the heat transfer medium is a
phase
change material which has a much higher heat absorption capacity than water,
for
2o example. Since the heat transfer medium is in a solid state of aggregation
which it
will also retain during heat absorption, it will not be necessary to provide
the heat
transfer medium 20 or the cooling element 12 with sealing properties.
Supporting the
individual heat transfer media 20 within said passive cooling element 12 will
suffice.
Said heat transfer medium is moreover provided in the form of a PCM device so
as to
2s cause said heat transfer medium 20 to store the thermal energy generated by
the
load on the electronic component that can no longer be absorbed and carried
off by
the passive cooling element 18, at the same time retaining its solid state of
aggregation, and to release said heat again at a time when the load on the
electronic
component is lower.
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6
Figure 2 is a schematic top view of the cooling device 10 according to Figure
1. This
drawing shows the arrangement of the individual heat transfer media 20 between
the
individual cooling ribs or fins 14 of said cooling element 12.
s Figure 3 is a lateral view of the cooling device according to Figure 1. This
drawing
shows that said cooling element 12 includes attachment means 22, at the area
of said
bottom element 16 and on its sides, for attaching said cooling device 10
together with
the electronic component to be cooled. Furthermore, one can see that, in the
embodiment illustrated, the heat transfer media 20 are provided in the form of
disks.
io However, the size and shape of said heat transfer media 20 may be chosen at
random. The size and the number of said heat transfer media 20 will allow,
amongst
other things, the adjustment of the required operational temperatures for the
respective electronic components intended to be cooled.
