Heat sink, in particular for electronic components

A heat sink (2) for electronic components (1) comprises: a base portion (3) fitted with device (4) for coupling with a fixed support plane (5) of an apparatus; a plane surface (6), positioned in proximity to the base portion (3), in contact with a corresponding surface (7) of the electronic component (1), and an additional heat dissipation portion (8) comprising a prolongation (9) of the base portion (3) from which extend a plurality of fins (10); an elastically yielding element (11) acts between the heat sink (2) and the electronic component (1) to obtain a stable positioning of the surface (7) of the component itself to the related plane surface (6) of the heat sink (2); a pair of fins (10a, 10b), contiguous to each other, presents a respective inner wall (12, 13), sush walls being opposite one to the other and so shaped as to define a compartment (14) for stably housing a portion (15) of the elastically yielding element (11).

BACKGROUND OF THE INVENTION 
The present invention relates to a heat sink, in particular for use with 
electronic components. 
At present, electronic components and the related circuits have reached 
high levels of operating reliability and precision, so much so that they 
are used in the most disparate technological fields both as major 
components (see the common Personal Computers), and to integrate and 
support apparatuses ranging from control systems for welding machines, to 
command and control systems for automated machines, to regulating systems 
for the proper operation of engines, etc. 
Usually such electronic circuits essentially comprise a mother board 
whereon are pre-printed connecting circuits for pluralities of electronic 
components, which are arranged or in turn connected to the mother board, 
with the whole set enclosed in a chassis. 
In combination with one or more of such components--which we usually define 
as processors--a related heat sink is used which allows to dissipate the 
heat generated by the steady state operation of the components themselves 
which, as is well known, require controlled operating temperatures. Such 
heat sinks generally comprise a first portion destined to be in contact 
with the related electronic component and a second portion shaped to 
present a plurality of fins able to favour better heat dissipation. 
To couple the electronic component and the heat sink in such a way as to 
allow for an optimal contact of the related surfaces, various solutions 
are currently in existence, studied also according to the internal 
structure (mother board and component) and to the external structure 
(chassis) of the apparatuses. 
Currently, the most widely employed provide for the use of an elastic 
element acting on the electronic component to press it against the first 
portion of the heat sink: the patent EP-622.983 shows one of these 
solutions, where the elastic element holding the electronic component 
comprises a metal platelet fastened, at one of its ends, to a wall of the 
chassis by means of a screw, whilst the development of the platelet is 
such that one of its portions is in contact with the electronic component 
which in turn is stably interposed between the platelet itself and the 
appropriate surface of the first portion of the heat sink. 
Another known solution is to apply the elastic holding element (in practice 
a spring) directly onto the aforesaid first portion of the heat sink: in 
this case a recess or a seat is obtained on the upper part of the first 
portion, wherein is stably fastened one end of the elastic element; the 
latter is shaped in such a way as to present its active portion in contact 
with the component opposite to the lower part of the first portion of the 
heat sink. 
The first of the solutions described above presents the drawback stemming 
from the mounting complexity due to the need to fasten the elastic 
platelet with a screw which cannot always be positioned close to the 
component and to the heat sink, making it necessary to apply platelets 
which are long, bulky, and not always reliable in holding the component, 
in addition to requiring fastening operations which are not always easy to 
perform in structures of extremely reduced size. 
The second solution described presents a reduced size of the 
dissipator--holding spring--component set with respect to the previous 
solution, but its clasping system is not very reliable and mounting the 
spring on the dissipator is awkward; moreover, the first portion of the 
heat sink has to be enlarged in order to obtain the seat for fastening the 
spring, thus decreasing the useful surface area for heat dissipation. 
SUMMARY OF THE INVENTION 
The object of the present invention therefore is to eliminate the drawbacks 
mentioned above through the realisation of a heat sink for electronic 
components presenting a structure of reduced size, with rapid fastening of 
the electronic component and of the retaining spring of the latter, whilst 
maintaining a large surface area for heat dissipation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In accordance with the figures of the enclosed drawings, and with 
particular reference to FIGS. 1 and 3, a heat sink such as the subject one 
is usable to cool electronic components 1 (shown only schematically here, 
as they are known in the art and are not strictly part of the invention). 
The heat sink, indicated in its entirety as 2, comprises a base portion 3 
provided with means 4 for coupling with a fixed support plane 5 of an 
apparatus: in practice, the base portion 3 is provided with a threaded 
seat 20 inside which is screwingly engaged an appropriate screw 21 passing 
within a hole 22 obtained on plane 5 which in practice is a mother board 
of the apparatus (here the mother board is only partially shown, as it is 
known in the art and is not part of the subject invention). 
The base portion 3 is provided with a plane surface 6 in contact with a 
corresponding surface 7 of the aforesaid electronic component 1 and with 
an additional portion 8 for heat dissipation constituted by an actual 
prolongation 9 of the base portion 3: in FIGS. 1 and 3, such prolongations 
9 can develop from the base portion 3 vertically, with respect to the 
mother board 5, or horizontally or in any other direction depending on the 
size of the components of the apparatus wherein they are to be inserted. 
From this prolongation 9 extend, from one or from opposite bands of the 
prolongation itself, a plurality of fins 10 parallel one to the other (or 
even inclined with respect to prolongation 9) and able to allow the 
dissipation of the heat generated by the electronic component 1. 
The latter is positioned and held against the surface 6 of the heat sink 2 
by means of an elastically yielding element 11, in practice an actual 
spring, acting between the heat sink 2 and the electronic component 1 so 
as to obtain the fastening of the latter on the heat sink 2 thanks to the 
spring-back of the spring 11. 
As can also be seen in FIG. 2, at least one pair of the aforesaid fins 10a 
and 10b, contiguous to each other, presents a respective inner wall 12 and 
13 opposite each other and so shaped as to define a compartment 14 for 
stably housing a portion 15 of the aforesaid elastically yielding element 
11. 
As can be seen in FIGS. 1 and 3, the pair of fins 10a and 10b in question 
is located, preferentially, in proximity to the aforesaid plane surface 6 
in contact with the electronic component 1 to allow the use of a spring 11 
of reduced size and thus more reliable in holding the electronic component 
1. 
On one of the aforesaid inner walls 12, 13 of the fins 10a and 10b (in the 
case of FIG. 2 it is the one indicated as 12 of the fin 10a) can be 
obtained an undercut 16 which defines a tooth 17 positioned in proximity 
to the free end of the fin 10a able to provide a blocking stop of the 
aforesaid portion 15 of the spring 11 within the compartment 14. 
The spring 11, in turn, presents the clasping portion 15 which develops in 
such a way as to touch at least in one respective point each of the inner 
walls 12, 13 of the fins 10a and 10b, whereof one point normally coincides 
with the aforesaid tooth 17. The pairs of fins 10a and 10b may present an 
equal extension L starting from the central prolongation 9 (as in FIG. 3), 
or present different extensions L1 and L2, also starting from central 
prolongation 9; such extensions will clearly depend on the configuration 
of the heat sink 2 and on the configuration of the portion 15 of the 
spring 11. 
The portion 15 of the spring 11 in the case of FIGS. 1 and 2 develops 
according to an arched profile in such a way as to rest with the free end 
15a on the wall 13 and in proximity to the bottom of the compartment 14, 
whilst the central arched portion 15b is in contact with the aforesaid 
tooth 17 with which the wall 12 is provided. 
This configuration of the portion 15 of the spring 11 allows a translation, 
of a few millimetres, of the portion itself within the compartment 14 (see 
arrow F in FIG. 2), i.e. its distance from the central prolongation 9, 
without impinging upon its fastening, but at the same time providing the 
possibility of varying the holding load of the portion 15c of the spring 
11 on the electronic component 1 according to the size of the latter and 
to the needs noted at that moment on the spring itself or within the 
apparatus. 
A heat sink thus structured, therefore, allows: 
the composition of electronic component--heat sink--spring sets of reduced 
size; 
high reliability of the overall structure of the heat sink since the heat 
sink itself maintains its structural characteristics; 
heat dissipation efficiency unchanged, or changed for the better, in 
comparison with prior art solutions, since the spring is housed between 
two fins with no need to work on or alter the structure of the heat sink. 
The invention thus conceived can be subject to numerous modifications and 
variations, without thereby departing from the scope of the inventive 
concept. Moreover, all components may be replaced with technically 
equivalent elements.