DE19704549A1 - Heatsinks for electrical and electronic components - Google Patents

Description

The invention relates to a heat sink for electrical or electronic components.

Previously known generic heat sinks are made of a solid material and are - if necessary with the interposition of a thermal paste - to be cooled Components fixed by screwing or gluing. You are good from one thermally conductive material, mostly made of aluminum.

A disadvantage of such heat sinks is that they can be attached to only one single component are designed so that also for cooling closely side by side lying components must each use separate heat sinks.

The biggest problem of adjacent components to which a common Heat sink to be arranged represents their different height. Of course it would be possible to form a solid heatsink in such a way that it closes with everyone cooling components can be connected; but this is only for the special one Component configuration usable for which it was designed; for a different kind Component arrangement would have to be worked out again a special production.

The object of the invention is to avoid this disadvantage and a heat sink Specify the type mentioned above, which is a group of side by side Component housings can be created and different configurations of the cooling components is customizable.

According to the invention, this is achieved by a heat sink, which is a deformable sleeve is at least partially filled with a heat transfer medium.

Such a heat sink can be adapted to any component grouping, it creates itself all individual components, which ensures good heat transfer and therefore efficient Heat dissipation is guaranteed.

According to a variant of the invention it can be provided that the heat transfer medium pasty consistency because the heat sink adapts well to the ones to be cooled Molds components and maintains its shape.

According to a further embodiment variant, the heat transfer medium can be liquid Have consistency.

Liquid heat transfer media are particularly good for absorbing and removing heat suitable, so that specially designed heat sink according to this training variant are effective.

According to an alternative embodiment of the invention, it can be provided that the heat transfer medium through a solid, which is present in a large number of individual parts, preferably good heat-conducting material is formed.

Due to the good thermal conductivity of solid materials bring in inventive In this way, heat sinks designed satisfactory results, similar to conventional rigid ones, heat sink also made of solid material.

In this connection it can be provided that the solid material has a powdery consistency having.  

Such a heat-conducting powder is particularly simple to manufacture, so that the Manufacturing costs of such a heat sink can be kept low.

In this connection it can be provided that the particles of the solid, powdery Material in the form of beads.

Spheres have a large volume in comparison to other geometric bodies Compared to their surface and can be placed very close together, so that at this configuration of the granulate particles in the heat-dissipating material Heat sink sleeve can be accommodated. This allows the heat sink to have a high Heat dissipation can be awarded.

Another embodiment of the invention can be that the solid material in shape of flexible parts such as B. wires, strips, foils or the like. Is present.

This results in relatively long heat transport distances that are free of material transitions are, so that a higher thermal conductivity can be achieved by this design can.

It is advantageous if the solid material by a metal such. B. copper, aluminum or the like. is formed because metal is simply in the necessary form - granules, strips, wires or the like. - Can be brought, good thermal conductivity and the necessary Has temperature resistance.

If a liquid or pasty heat transfer medium is used, it can be provided be that the heat transfer medium with a solid, in the form of a variety of items present material is mixed.

Solid heat transfer media, especially metals, have a particularly high thermal conductivity, so that by adding them to a liquid heat transfer medium, its thermal conductivity can be easily increased.

According to a preferred embodiment of the invention it can be provided that the liquid heat transfer medium through water, paraffin, benzyltoluene, biphenyl, terphenyl, Silicone oils or the like is formed, since these heat transfer media are particularly good for the electronic components occurring temperature range are suitable.

Furthermore, it can be provided that the liquid heat transfer medium by a refrigerant such as fully or partially halogenated hydrocarbons such. B. methyl chloride, di- or Trichloride fluoromethane or the like; or by a halogen-free refrigerant such as B .: Sulfur dioxide, carbon dioxide or the like. Is formed.

These media have a low boiling point, so that they heat the in present application already occurring low temperatures Evaporation and subsequent condensation.

According to another variant of the invention it can be provided that the Heat transfer medium has gaseous consistency.

As a result, the heat sink is particularly easy to deform and can be placed next to one another Components that differ considerably in their sizes can be created.

In all the design variants mentioned so far, it can be provided that the casing is formed by a film.  

A film is particularly easy to deform, so that the weight of the Heat transfer medium an optimal concern of the heat sink on the individual Components and thus optimal heat dissipation can be achieved.

In a further development of the invention it can be provided that the shell consists of several Pieces of film is assembled, which pieces of film, preferably along their Boundary course, are interconnected.

This type of training allows a particularly simple manufacturing process.

In this connection it can be provided that the pieces of film with each other are welded.

The individual pieces of film are thus connected to one another in a particularly reliable manner. It can be advantageous if the film or the film pieces are made of a good heat conductor Material, preferably made of a metal such as copper, aluminum or the like. Because as a result, the heat generated in the components is particularly low-loss to the Ambient atmosphere can be released.

A particularly preferred embodiment of the invention may be that the Sheath is formed from two pieces of film, which pieces of film, if necessary, from each other have different strength properties.

By using two pieces of film, the manufacturing process, in particular the process of connecting the two pieces of film can be made particularly simple. In this context, a development of the invention can consist in that the first piece of film is plastically deformable and the second piece of film is elastically deformable.

The piece of film facing the components to be cooled becomes plastically deformable executed, the heat sink can be placed well on the individual housing, whereby due to the elastic design of the second piece of film, the heat sink is always one certain basic form is kept.

If the heat transfer medium has solid material present in flexible parts, it can According to a preferred embodiment of the invention, the flexible parts, such as B. wires, strips, foils or the like. Each with at least one end on the inside the envelope are fixed.

This is a good contact and thus a low-loss heat transfer between the shell and Heat transfer medium ensured.

A further development of the invention can provide that the casing has openings, Through which openings heat transfer medium can be supplied and removed.

In this way, a circuit can be set up in which the heat transfer medium moves becomes, which increases the amount of heat dissipated by the heat sink can.

According to another variant of the invention it can be provided that the casing at least has a tubular formation, in which formation evaporates Heat transfer medium can condense.

Also by means of this molding, which is based on the principle of a "heat pipe", the dissipated amount of heat can be increased.  

According to a further embodiment of the invention it can be provided that on the shell at least one solid body is set.

With such an arrangement, the envelope filled with heat transfer medium only becomes Compensating for the difference in height between the individual components used actual heat dissipation takes place via the, advantageously in the form of a conventional heat sink trained, fixed to the shell fixed body.

In this context, it can be provided in a further development of the invention that on the solid body next to the shell at least one more, at least partially with one Heat transfer medium filled, deformable shell is set.

This enables the heat sink to be connected to two different groups of electronic components - as is the case with parallel plug-in cards is - be created.

The invention will now be described with reference to the preferred shown in the drawings Embodiments explained in more detail.

Show it:

Figure 1 is a equipped with microchips printed circuit board with an embodiment of the invention in elevation in section.

Fig. 2a, b the circuit board of Figure 1 with a preferred embodiment of the invention in plan and elevation.

Fig. 3, 4 developments of the invention the heat sink of Figure 2a, b in elevation.

FIG. 5 shows the heat sink of Figure 2a, b with a fixed to it solid cooling element.

Fig. 6 shows an embodiment of the invention for the simultaneous cooling of two component groups in plan and

Fig. 7a, b inventive heat sink with a fixed heat transfer medium in section.

Electronic components which are arranged on a common printed circuit board generally have different housing shapes from one another. An example of this is shown in FIG. 1, in which a grouping of microchips arranged on a common printed circuit board 1 is shown. Both components 2 , the connection pins of which protrude through holes in the conductor track and are soldered to the underside 10 of the circuit board 1 , have different heights, but above all there is a significant difference in size compared to surface-mounted components 3 (SMD components).

It is often necessary for all components 2 , 3 to be provided with a heat sink, it being particularly advantageous in this context to provide only a single heat sink for the entire assembly, which should advantageously be detachably attached to components 2 , 3 , so that a possibly necessary replacement of a component 2 , 3 can be carried out in a simple manner.

A heat sink 4 according to the invention, the basic structure of which is also shown in FIG. 1, has a deformable sleeve 5 , which sleeve 5 is at least partially filled with a heat transfer medium 6 . The heat sink 4 according to the invention thus corresponds in terms of its heat dissipation properties to a conventional, rigid heat sink.

The sleeve 5 could be made of a sheet-like material that is bent according to the contours of the components 2 , 3 to be cooled. However, the heat sink 4 would only be adaptable to another component configuration with some effort, so that the casing 5 is advantageously formed from a film.

The heat transfer medium 6 received by the casing 5 must be able to adapt to the shape of the casing 5 , for which purpose it has pasty or liquid consistency.

Alternatively, it is also possible to have a fixed one, in a variety of individual parts to use the present, preferably good heat-conducting material.

The individual parts can be relatively small, so that there is a powdery consistency of the solid heat transfer medium 6 or else the shape of flexible parts 7 , such as. B. wires, strips, foils or the like. Have.

The result is a felt-like structure of the heat transfer medium, the main advantage of which is that that the individual elements form well thermally conductive, elongated discharge paths.

In order also in such heat carriers are of sufficient ductility of the sleeve 5 to ensure the sheath 5 may not tightly but only partially, with the strip-powdery, film-like or wire-like heat transfer medium to be filled.

In this context, in order to achieve good heat dissipation, it is favorable to use a good one to use heat-conducting material. The powder, strip, film or wire-shaped heat transfer medium therefore made of a metal, such as. B. copper, aluminum or the like. educated.

Furthermore, a combination of the two heat transfer media described is conceivable, ie the heat transfer medium 6 has liquid or pasty consistency and is mixed with a solid material in one of the described forms.

The individual particles of the powdery material do not have a specific geometric shape have, since this is irrelevant for the heat dissipation properties. Preferably the solid material has very small particle sizes, such as those e.g. B. by grinding the Material arise. However, it is equally possible to use the heat-dissipating material as Granules, the particles of which have a certain geometric shape, e.g. B. spherical, have use.

The material for a liquid heat transfer medium 6 includes water, paraffin, benzyltoluene, biphenyl, terphenyl, silicone oils or the like, but also refrigerants such as fully or partially halogenated hydrocarbons such as, for. B. methyl chloride, di- or trichloride fluoromethane or the like; or by a halogen-free refrigerant such as B. sulfur dioxide, carbon dioxide or the like. In question.

Provision can also be made to use a liquid or pasty heat transfer medium 6 which has thixotropic properties. This has the advantage that the heat sink 4 can be deformed very easily under the action of mechanical forces and can therefore be adapted to component groups; in the idle state, however, that is to say to a certain extent when it is lying on components, and is therefore protected against detachment from the components even when the component is moving.

Finally, it is also possible to use a gaseous heat transfer medium.  

In all of the training variants described, a "cushion-like" heat sink 4 is obtained, which can simply be placed on a wide variety of component groups. The film can be made of any materials, with a view to achieving good heat transfer from the components to be cooled to the heat transfer medium 6 , it is favorable to use a good heat-conducting material. Since the housings of electronic components 2 , 3 generally consist of insulating plastic, it is also entirely possible to use a metal such as copper or aluminum.

A particularly preferred embodiment of the invention is shown in FIGS. 2a, b. Here, the sleeve 5 of the heat sink 4 according to the invention is composed of several, in this specific case, two pieces of film 50 , 51 . The two pieces of film 50 , 51 have a rectangular shape, are congruently cut to one another and are superimposed congruently. They are tightly connected to each other along their boundary. In the cavity enclosed by the two pieces of film 50 , 51 there is a liquid, pasty, powder, strip, wire, film solid or gaseous heat transfer medium 6 analogous to the embodiment according to FIG. 1.

The connection of the film pieces 50 , 51 can be done in various ways, such as. B. done by gluing, but preferably the pieces of film 50 , 51 are welded to each other because the connection can be made particularly durable and tight. When the shell 5 is composed of a plurality of film pieces 50 , 51 , these can be produced from one and the same material and with the same strength properties, but it is also possible to use different materials or by forming the film pieces 50 , 51 with different thicknesses to give individual pieces of film 50 , 51 different strength and deformation properties.

In this context, the film piece 50 facing the components 2 , 3 could be designed to be plastically deformable in order to ensure that the heat sink 4 lies flat on the individual components 2 , 3 , whereas the film piece 51 is designed to be elastically deformable, that is to say resilient.

In order to increase the power of the heat sink 4 according to the invention, that is to say the amount of heat that it dissipates per unit of time, various measures are conceivable, the most important of which are shown in FIGS. 3-5 and are explained below.

According to the embodiment according to FIG. 3, the casing 4 is provided with openings 41 , 42 , through which openings heat transfer medium 6 can be supplied and removed. In this case, a heat transfer medium circuit can expediently be set up, in which the heat transfer medium 6 heated by the components 2 , 3 is discharged via one opening 42 , cooled and then returned to the heat sink 4 via the other opening 41 .

The sleeve 4 of the embodiment according to FIG. 4 is liquid-tight, but has a tubular projection 43 and is only partially filled with a liquid heat transfer medium 6 . In this embodiment, the heat transfer medium 6 of the heat sink 4 is evaporated by the heat of the components 2 , 3 . This steam rises into the tubular molding 43 , at the upper end of which it condenses - due to the lower temperature prevailing there - and thus emits thermal energy.

Finally, an embodiment of the invention according to FIG. 5 is also conceivable, in which one, possibly also a plurality of, solid bodies 44 are fixed on the casing 4 . These bodies 44, which are preferably made of a good heat-conducting material, correspond in their effect to the conventional rigid heat sinks, that is to say on the one hand they store the heat supplied to them and on the other hand they also give them off to the surrounding atmosphere.

Although not shown in separate drawings, any combinations of the measures described last for improving the heat dissipation are also possible. For example, a heat sink 4 equipped with a solid body 44 could have openings 41 , 42 for building up a heat transfer medium circuit, or it could be provided with a tubular projection 43 , which corresponds in function to a "heat pipe".

It often happens that an electronic device, such as. B. computers, control and regulating devices such as PLC or the like. Must be assembled from a variety of electronic modules. As shown in FIG. 6, each of the modules is often built on a separate circuit carrier 11 , 12 in order to obtain a modular, easy-to-maintain structure. The individual circuit carriers 11 , 12 - so-called plug-in cards - are plugged onto a common plug-in board 13 carrying the connecting lines necessary between the modules, in such a way that they run parallel to one another. If it is necessary to cool the components 2 , 3 of two adjacent plug-in cards 11 , 12 , a heat sink 4 according to the invention, as has been described up to now, can also be used for this.

In connection with this area of application, however, the heat sink can also be designed according to FIG. 6 and formed from a solid, plate-shaped body 44 which has a first casing 5 and a further casing 5 '. Both shells 5 , 5 'are deformable and at least partially filled with a heat transfer medium 6 of the composition already described.

The plate-shaped body 44 can serve as a separating layer between the two shells 5 , 5 ', so that the heat transfer media 6 contained therein do not come into contact with each other. It can just as well be designed to be permeable to the heat transfer medium 6 and optionally have openings for the supply and discharge of the heat transfer medium 6 or a central heat pipe construction (tubular projection 43 ).

If a solid material present in flexible parts 7 is used as the heat transfer medium 6 , if appropriate in combination with a liquid, the individual parts 7 , that is to say wires, strips, foils or the like, can be shown in FIGS. 7a, b Be set inside the shell 5 .

According to FIG. 7a, they are each connected to the sheath 5 at one end 70 , while their other end 71 is free and resiliently supported on the sheath section opposite its fixing point. In principle, the parts 7 can be fixed at any points on the casing 5 , that is to say either on the casing section resting on the components 2 , 3 or also on the casing section spaced apart from the components 2 , 3 .

In this connection, an embodiment according to FIG. 7b is also conceivable, in which the individual heat transfer medium parts 7 are fixed on both sides of the inner wall of the casing. Due to the flexibility of the individual parts 7 , the heat sink 4 remains deformable as a whole. It is particularly advantageous in this embodiment that there are continuous heat dissipation paths through the entire heat sink 4 .

Also, in a in FIG. 7 configured heat sink 4, a fixed to the sheath 5 of solid bodies 44 may be provided, is equipped with a tubular conformation, or openings for the supply and discharge the heat transfer medium 6, or a combination of these measures is also possible.

Claims (23)

1. heat sink for electrical or electronic components characterized by a deformable shell ( 5 ) which is at least partially filled with a heat transfer medium ( 6 ). 2. Heat sink according to claim 1, characterized in that the heat transfer medium ( 6 ) has pasty consistency. 3. Heat sink according to claim 1, characterized in that the heat transfer medium ( 6 ) has a liquid consistency. 4. Heat sink according to claim 1, characterized in that the heat transfer medium ( 6 ) is formed by a solid, present in a plurality of individual parts, preferably good heat-conducting material. 5. Heat sink according to claim 4, characterized in that the solid material has a powdery consistency. 6. Heat sink according to claim 5, characterized in that the particles of the solid, powdery material in the form of beads. 7. A heat sink according to claim 4, characterized in that the solid material in Form of flexible parts 7, such as. B. wires, strips, foils or the like. Is present. 8. Heat sink according to one of claims 4 to 7, characterized in that the fixed Material through a metal such. B. copper, aluminum. Like. Is formed. 9. Heat sink according to claim 2 or 3, characterized in that the liquid or pasty heat transfer medium ( 6 ) is mixed with a solid material present in a large number of individual parts. 10. Heat sink according to one of claims 2, 3 or 9, characterized in that the liquid heat transfer medium ( 6 ) is formed by water, paraffin, benzyltoluene, biphenyl, terphenyl, silicone oils or the like. 11. Heat sink according to one of claims 2, 3 or 9, characterized in that the liquid heat transfer medium ( 6 ) by a refrigerant such as fully or partially halogenated hydrocarbons such as. B. methyl chloride, di- or trichloride fluoromethane or the like; or by a halogen-free refrigerant such as For example: sulfur dioxide, carbon dioxide or the like is formed. 12. Heat sink according to claim 1, characterized in that the heat transfer medium ( 6 ) has a gaseous consistency. 13. Heat sink according to one of claims 1 to 12, characterized in that the sheath ( 5 ) is formed by a film. 14. A heat sink according to claim 13, characterized in that the sheath ( 5 ) is composed of a plurality of pieces of film ( 50 , 51 ), which pieces of film ( 50 , 51 ), preferably along their edge course, are connected to each other. 15. Heatsink according to claim 14, characterized in that the film pieces ( 50 , 51 ) are welded together. 16. A heat sink according to claim 13, 14 or 15, characterized in that the film or the film pieces ( 50 , 51 ) made of a good heat-conducting material, preferably of a metal such as copper, aluminum or the like. 17. Heat sink according to one of claims 13 to 16, characterized in that the casing ( 5 ) is formed from two pieces of film ( 50 , 51 ), which pieces of film ( 50 , 51 ) optionally have different strength properties. 18. Heat sink according to claim 17, characterized in that the first film piece ( 50 ) is plastically deformable and the second film piece ( 51 ) is elastically deformable. 19. Heatsink according to one of claims 4 to 18, wherein the heat transfer medium ( 6 ) solid, in flexible parts ( 7 ) present material, characterized in that the flexible parts ( 7 ), such as. B. wires, strips, foils or the like. Each with at least one end ( 70 ) on the inside of the shell ( 5 ) are fixed. 20. Heat sink according to one of claims 1 to 19, characterized in that the sheath ( 5 ) has openings ( 41 , 42 ) through which openings ( 41 , 42 ) heat transfer medium ( 6 ) can be supplied and removed. 21. Heat sink according to one of claims 3, 9, 10, 11 or 13-19, characterized in that the casing ( 5 ) has at least one tubular projection ( 43 ), in which projection ( 43 ) evaporated heat transfer medium ( 6 ) can condense . 22. Heatsink according to one of claims 1 to 21, characterized in that at least one solid body ( 44 ) is fixed to the shell ( 5 ). 23. Heat sink according to claim 22, characterized in that at least one further, at least partially filled with a heat transfer medium ( 6 ), deformable sleeve ( 5 ') is fixed to the fixed body ( 44 ) in addition to the sleeve ( 5 ).