EP2782676A2

EP2782676A2 - Vapour chamber

Info

Publication number: EP2782676A2
Application number: EP12791434.9A
Authority: EP
Inventors: Günter Tenzler; Christian George; Torsten Burdack
Original assignee: Inheco Industrial Heating and Cooling GmbH; INHECO Ind HEATING AND COOLING GmbH
Current assignee: Inheco Industrial Heating and Cooling GmbH; INHECO Ind HEATING AND COOLING GmbH
Priority date: 2011-11-23
Filing date: 2012-11-23
Publication date: 2014-10-01
Anticipated expiration: 2032-11-23
Also published as: DE102011119174A1; WO2013075839A3; WO2013075839A2; EP2782676B1; ES2758883T3; US20140311706A1

Abstract

The present invention relates to a vapour chamber (1), comprising a lower shell (3) and an upper shell (4), wherein at least one gas-tight and liquid-tight intermediate area (11) is formed between lower shell (3) and upper shell (4), in which area a fluid working medium is accommodated and a porous material (12, 13, 30) that interacts with the fluid is arranged; the porous material (12, 13) is in contact, at least in some areas, with the upper shell (4) and/or the lower shell (3), but does not completely fill the at least one intermediate area (11), forming at least one cavity-like vapour gap (14). The upper shell (4) of the vapour chamber (1) has on its top side a plurality of indentations (6) which are distributed over the surface (5) thereof, extend towards the lower shell (3) and act as sample receptacles, into which samples to be temperature-controlled (7) can be introduced from the top using the vapour chamber (1). At least one vapour gap (14) delimited at least partially by the porous material (12, 13) extends three-dimensionally in such a manner that it surrounds at least partially laterally and within the intermediate area (11) located between the upper and lower shell (4, 3), one or more indentations (6) of the upper shell (4). Some of the indentations (6) formed on the upper shell (4) and extending towards the lower shell (3), preferably all indentations (6), are in contact with the bottom of the lower shell (3). At least a part of the indentations (6) in contact with the lower shell (3) are connected on their underside to the lower shell (3), wherein each indentation (6) of the upper shell (4) is in contact on the intermediate space side with the porous material (13, 30), and wherein the porous material (13, 30) adjacent to the indentations (6) on the intermediate space side is in contact with the porous material (12, 30) adjacent to the lower shell (3) in the region of the indentations (6) concerned.

Description

Vapor Chamber

The present invention relates to a vapor chamber comprising a lower shell and an upper shell, wherein between the lower shell and upper shell at least one gas- and liquid-tight gap is formed, in which a fluid working medium is accommodated and a cooperating with the fluid working medium porous material is arranged, wherein the porous Material at least partially touches the upper shell and / or the lower shell, but not completely fills the at least one intermediate space to form at least one cavity-like steam gap.

Such vapor chambers, which are designed in the manner of a generally flat and flat-shaped heat pipe (so-called heat pipe) and are based on its operating principle, are known from the prior art, e.g. from the WO

2005/114084 A1, well known and have known to have a very good thermal conductivity. Furthermore, FIG. 7 of US Pat. No. 3,680,189 also shows a vapor chamber of the type mentioned at the beginning, in which the lower and upper shells are in each case plate-shaped, the upper and lower shells having bars which are arranged on the edge side for forming the space required for a vapor chamber rectangular cross-section - gas and liquid-tight - are interconnected.

An existing temperature difference between the lower and upper shell of a Vapor Chamber is compensated by the fact that the fluid working medium evaporates, for example in the hotter lower shell, whereupon the steam - due to an adjusting pressure gradient - through the steam gap (ie a suitable running in the Vapor Chamber Steam channel) in the direction of the cooler upper shell, where it condenses again. The porous material within the Vapor Chamber serves to receive and transport the condensed, ie liquid phase of the working medium in order to seal it within the space between the upper and lower shell by capillary forces. to move in the direction of the warmer side of the Vapor Chamber, where the working medium then - if temperature equilibrium has not yet established an equilibrium state - can re-evaporate. The porous material advantageously produces a connection between the upper and lower shell extending in the interior of the vapor chamber in order to ensure effective transport of the liquid phase of the working medium between the two mutually facing (inner) sides of the upper and lower shell.

The latent heat absorbed or released by the working medium at the respective phase transitions in a continuous process and the transport of the vaporous and liquid phase of the working medium through the vapor gap and the porous medium ensure a very rapid compensation of a temperature between the upper and lower shell. temperature difference, so that, for example with active heating of the lower shell, which can be done by means of underside mounted heating medium, a very rapid heating of the upper shell takes place. Another advantage is that - even with a possibly only selectively or at several points / areas ensuing heating of the lower shell - an acceptable for most applications homogeneity in the temperature distribution on the upper shell is achieved.

Furthermore, by means of a vapor chamber, heat can also be dissipated from the upper shell or lower shell (or a thermally coupled component) in a very effective manner, by thermally coupling the respective other shell to a suitable heat sink.

The working range of a Vapor Chamber is dictated by the properties of the working medium contained therein (eg water) and the pressure prevailing in the Vapor Chamber and can therefore be adjusted, for example, by a suitable choice of (at least one) working medium. Vapor Chambers - so designed in a flat design heatpipes - of the generic type are often used in conjunction with suitable heating and / or cooling agents for the most uniform tempering of standing with the heat pipe in (direct or indirect) thermal contact moldings, which in turn - Form of indentations provided on the upper side - have a plurality of receptacles for samples to be exposed therein at a certain temperature.

In particular, vapor chambers of the generic type are used in so-called thermocyclers in which, in the context of the simultaneous temperature control of a plurality of (biological) samples, e.g. For the purpose of DNA amplification, a temperature course suitable for carrying out the polymerase chain reaction (PCR) must be run through several times cyclically. It goes without saying that a particularly precise temperature control of the various samples is just as desirable as the fastest possible passage of the temperature cycle, in which it is essential that the different samples in different time sequence at different temperatures (for a given period) exposed become. A typical cycle initially involves heating the samples to about 95 ° C. (for the process step of so-called denaturing, melting), then cooling to about 55 ° C. (for the process step of so-called primer hybridization) and another Heating to approx. 72 ° C (for the

Process step of the so-called elongation), whereupon the cycle begins again by further heating to 95 ° C. These temperature levels should be kept as accurately as possible for all samples to be tempered at the same time, whereby the heating and cooling processes required between the temperature levels should be able to be carried out as quickly as possible.

The thermocyclers hitherto known from the prior art, as described, for example, in EP 1 710 017 A1, WO 01/24930 A1 or WO 2004/105947 A1, typically comprise a sandwich structure of a heat sink, at least one generic vapor Chamber ("thermal base", "heat pipe"), a possibly consisting of several elements heating and, if necessary, coolant (eg in execution of at least one Peltier or PTC element), which may be located above or below the vapor chamber and a sample holding body ("thermal block" or "sample block" or "reaction block") in direct thermal contact with the heating means and / or the vapor chamber, with a plurality of indentations arranged on the upper side of its surface, into which the one be exposed to certain temperature profile samples - if necessary, within suitable sample containers - for the purpose of their temperature can be introduced. Each indentation acts as a receptacle for a sample to be tempered therein and is advantageously designed in such a way that a sample container which can be inserted from above, usually consisting of a thin plastic and which contains the sample to be tempered, makes contact with the surface for good heat transfer can be brought as a sample recording acting indentation.

The temperature-controlled in turn with the aid of at least one vapor chamber sample receiving body is usually solid made of silver (or aluminum), which in addition to the high weight of such a shaped body and a comparatively high heat capacity, which is particularly rapid temperature changes in the way, not with one inconvenient material and cost associated. Furthermore, the realization of a good uniformity of the temperature in the various sample receptacles (indentations) proves to be particularly difficult, in particular in the region of the recesses arranged at the edge or in a corner region of the sample receiving body.

In order to improve the homogeneity of the temperature which is established in the individual sample recordings, it has already been proposed in WO 01/24930 A1, instead of using a separate vapor chamber or heat pipe ("temperature compensation plate") below the reaction vessel receiving body, which is composed of several segments, individual tubulars mige heatpipes in the various segments of the reaction vessel receiving body to integrate so that they extend in a direction between two rows of reaction vessel holders. Here, too, the reaction vessel receiving body has a comparatively high heat capacity due to its otherwise massive construction.

Finally, US Pat. No. 5,161,609 A also shows various embodiments of a "heat pipe" principle vapor chamber of the type mentioned above for use in a thermal cycler, said vapor chamber due to the given design of the receiving the fluid working medium housing, which has an inner coating with porous material, at the same time serves to receive the samples to be tempered or to receive sample containers to be tempered.

In a first embodiment of the vapor chamber described in US Pat. No. 5,161,609 A, cylindrical passages through the vapor chamber are provided for the purpose of accommodating a plurality of sample containers to be tempered, which open to the top and bottom of the vapor chamber and from a steam gap are surrounded. This Vapor Chamber is heated or cooled by a heating / cooling source at its laterally peripheral edge and is provided with thermal insulation on the top and bottom and covered with a cap. In a second embodiment of the US

No. 5,161,609 A, a plurality of indentations acting as sample receptacles are provided on the upper side, with no details as far as the internal structure of the Vapor Chamber is concerned. This Vapor Chamber is also in contact with a heating / cooling source at its peripheral edge, with a heating or cooling cap covering the Vapor Chamber on the upper side.

Not described for both embodiments described above, as the coating of the inner walls of the vapor chamber is carried out with the porous material. It should also be noted that the working fluid for temperature control the non-edge arranged sample holders must cover relatively long transport routes, for example if this is condensed for the purpose of heating a sample in the passage passages or indentations and is returned by the porous material back to the heated edge.

Against this background, it is the object of the present invention to provide a Vapor Chamber of the type mentioned, which is particularly suitable for use in high-efficiency thermal cyclers (or in other devices for temperature control of samples) with the Vapor Chamber underside heated or cooling heating / cooling agents while allowing particularly rapid temperature changes in the context of the temperature of using the Vapor Chamber to be tempered samples. Furthermore, with the aid of a vapor chamber according to the invention, a plurality of samples should be temperature-controllable at the same time, to improve the homogeneity of the temperature acting on the individual samples.

This object is achieved with a Vapor Chamber according to the invention according to claim 1, which - in addition to the aforementioned features - among other things characterized in that the upper shell of the vapor chamber on the top side a plurality of distributed over the surface, extending in the direction of the lower shell and as a sample receiving indentations, in which using the vapor chamber to be tempered samples are introduced from above, wherein at least one at least partially limited by the porous material steam gap extends in such a three-dimensional that within the space between the upper and lower shell one or surrounds several indentations of the upper shell at least partially circumferentially laterally.

It is further provided according to the invention that at least part of the indentations formed on the upper shell and extending in the direction of the lower shell, preferably all indentations, touch the lower shell on the underside, that at least part of the registration part contacting the lower shell tions are connected to the underside of the lower shell, that each indentation of the upper shell is contacted on the space side with the porous material and that the gap side adjacent to the indentations porous material contacts the adjacent to the lower shell porous material in the region of the respective indentations.

The Vapor Chamber according to the invention is thus characterized u.a. characterized in that it has on the upper side a plurality of sample receptacles, which are formed by indentations in the upper space bounding the intermediate space for the (at least one) fluid working medium.

The recording of the samples to be tempered thus do not serve the indentations in a substantially solid component, which is to be tempered with the aid of at least one vapor chamber or heat pipe, but the vapor chamber itself becomes the sample receiving body by the upper space bounding the space for the working medium upper side has suitable indentations, which act as a sample holder. Compared with a sample block made of solid silver, as it is currently used in highly efficient thermal cyclers, a significantly improved thermal conductivity ([W / mK]) can be achieved (by up to a factor of 7), so that in the course of the temperature control of the Plenty of sample taking place heating and Abkühlvorgänge be performed much faster.

By virtue of the fact that in the present case at least one steam gap, ie the at least one vapor gap formed within the intermediate space, runs in such a three-dimensional manner that it surrounds at least one or more indentations laterally, at least in part, can at the same time improve the temperature homogeneity compared to the prior art , ie an always very small difference in the temperature in the various sample receptacles, be achieved, especially if otherwise usually not sufficiently fast or effectively tempered specimen receptacles, in particular the sample receptacles arranged at the edge or in a corner area, are surrounded either separately and / or in blocks by the (at least one) vapor gap, it being particularly advantageous in the context of the present invention if in each case a single uninterrupted steam gap (each) surrounding one or more indentations completely circumferentially.

A vapor gap is to be understood as the volume within the interspace between the upper shell and lower shell, in which the vapor phase of the working medium is transported within the vapor chamber according to the invention. If this is spoken of "at least one" steam gap, this of course includes the possibility that in this case not necessarily a single contiguous steam gap must penetrate the entire vapor chamber over its entire areal extent, but that instead a plurality of steam gaps can be provided , for example, from each other are separated by the transport of the liquid phase serving porous material and / or by at least one subdividing the space element of the lower and / or upper shell.

The porous material used in a vapor chamber according to the invention may in principle be any material which, owing to its porosity, is capillary to the liquid phase of the working medium (e.g., water) for receiving and transporting the liquid phase of the working medium.

The fact that in this case the vapor chamber by suitable indentations on its upper side even forms the sample receiving body, also proves to be extremely advantageous, since hereby the weight and heat capacity of a used for example in thermocyclers sample receiving body compared to massively designed sample receiving bodies from the prior art the technology can be significantly reduced, which - in addition to the improved performance in terms of heat transfer to the individual indentations / Probenaufnahmen - at the same time a massive cost savings in terms of reduced material costs.

Since, according to the invention, each indentation of the upper shell is contacted with the porous material on the inside, the porous material directly adjacent to the indentations can contribute to the material-bound heat transfer in the vapor chamber based on the heat pipe principle.

In addition, it is provided in the context of the invention that at least part of the formed on the upper shell and extending in the direction of the lower shell indentations, in particular all indentations, touch the lower shell, wherein at least a part (or more preferably all) of the lower shell touching Indentations on the underside connected to the lower shell, in particular soldered. This makes it possible, on the one hand, to improve the mechanical stability of a vapor chamber according to the invention, since the indentations forming the sample receptacles thus-at least in part-produce a mechanical support or connection between the upper shell and lower shell. On the other hand, this also simultaneously increases the thermal conductivity between the lower and upper shell, in particular in the region of the indentations forming the sample receptacles, especially if, as is provided according to the invention, the porous material adjoining the lower shell adjoins the respective indentations The porous material adjacent to the indentations on the interspace side comes into contact, which then also improves the material-bound heat transport within the vapor chamber. In the region of the indentations, that is to say working fluid condensing on the upper shell side, can thus be conveyed back through the porous material directly and over a short path to the heated lower shell. Similarly, when cooling the lower shell, the working medium condensing there of the vapor chamber shortest path to be transported to the respective indentations space side provided area of the porous material.

The indentations forming the sample receptacles in the upper shell of a vapor chamber according to the invention are advantageously distributed in a regular pattern over the surface of the upper shell and particularly preferably in number and geometry to the number and geometry of the cavities.

"Wells") commercially available microtiter plates, such as those used in the industrial processing of (biological) samples, adjusted so that a microtiter plate can be placed on the top of the vapor chamber such that the individual (filled with eg liquid samples from above and freely projecting downwards) cavities of the microtiter plate in each case an indentation of the upper shell with the best possible (planar) contact with the respective side wall of the indentation. Thus, in the upper shell, in particular, it is advantageous to use e.g. 24, 48 or 96 provided correspondingly regularly arranged indentations in order to be able to temper with the aid of the vapor chamber according to the invention as large a variety of samples simultaneously and defined.

As far as in the context of the present invention is spoken of that the Vapor Chamber has a lower shell and an upper shell, the terms chosen so far should not describe a specific geometry of the components in question, but rather express that the Vapor Chamber invention at least two parts ( one could therefore also speak of an upper part and a lower part), between which the gas- and liquid-tight intermediate space for receiving the working medium and the porous material is formed. Obviously, the upper and lower shell (or upper part and lower part) need not necessarily be formed by two separate baggage parts, but can - if necessary, for example, with the use of suitable forming processes - also integrally formed, but always a gas and liquid-tight space between the Vapor Chamber must be formed up or down limiting upper or lower part. Before- However, at least the lower shell or the upper shell with a peripheral edge formed thereon is actually configured like a shell, whereby the lateral boundary of the vapor chamber can be formed in a simple manner by the relevant edge of the lower or upper shell.

In a first preferred embodiment of the present invention, it is provided that in a Vapor Chamber according to the invention between the upper and lower shell at least one steam gap is provided which surrounds all indentations laterally outside and within the space between the lateral boundary of the Vapor Chamber and the edge arranged Indentations is formed. Of course, it can be advantageously provided that in particular the edge-side indentations (on their respective side facing the gap) with the within the

Interspaced porous material (at least partially) are in contact or are coated with it, so that (also) a particularly effective heat transfer is realized in this area.

Such a all-round indentations or sample receptacles en bloc circumferential steam gap leads - with a by design of the upper and lower shell (and the porous material) easy to realize geometry of the vapor chamber - that even the edge and in the corner of the upper shell arranged indentations all benefit from the outstanding thermal conductivity of a vapor chamber and can therefore be uniformly and quickly heated and / or cooled.

Furthermore, it is advantageously provided in a particular embodiment of the present invention that each indentation is completely surrounded by at least one steam gap, so that the outstanding thermal conductivity of a heat pipe in the region of each indentation serving indentation with the result of a particularly good temperature homogeneity over all sample recordings to the full extent comes. When doing so, in the Vapor Chamber a total of the entire Vapor Chamber penetrating and simultaneously each indentation is provided fully circumferentially circumferential steam gap, it can be achieved in the context of temperature control of all sample receiving (or the samples arranged therein) to achieve an almost best possible temperature homogeneity.

In the case of the present invention, it is also particularly preferable for the porous material to be formed by at least two porous material layers, of which a first material layer is disposed on the outer shell on the space side and a second material layer

formed intermediate space on the lower shell, wherein the first and second layers of material contact each other in regions and are spaced from each other in other areas to form the at least one vapor gap.

The porous material used in a heat pipe or the two abovementioned porous material layers may be e.g. consist of an initially substantially powdery material with spherical and / or rod-shaped material components (for example of copper) of identical or different dimensions, which may be made of e.g. as part of a liquid or pasty mass - first applied in a suitable layer thickness on the respective inner side of the lower and upper shell and then under the action of suitable high temperatures (in a kind of sintering process) there

is baked so to speak, which on the one hand - solidified on the one hand - to form the desired porous structure - and on the other hand at the Unterbzw. Upper shell, which are advantageously joined together in a later process step, attaches or metallurgical with it.

Practice has shown that when using two trained in the above sense top and bottom side material layers of porous material, which must touch each other in assembled upper and lower shell in particular in the region of the indentations, problems with regard to the Wärmeleitleitfähigkeit may occur, provided not excellent manufacturing tolerances are met. On the one hand it can In the process, unwanted gaps occur between the material layers formed on the top and bottom sides, which impair or prevent the capillary liquid transport in the region of the gap. On the other hand, it may possibly lead to upsetting of the porous material in the contact region of the two material layers, which also adversely affects the capillary liquid transport between the two material layers.

Therefore, it is provided in a preferred development of the present invention that the contact of the gap side adjacent to the indentations porous material and adjacent to the lower shell porous material is effected in that the porous material on the upper and lower shell as a total contiguous inner coating of the vapor Chamber is formed. In such an interrelated (gap-side) inner coating of the vapor chamber, the contact of the porous material provided on the top and bottom shells is thus given by a continuous and uninterrupted layer of porous material connecting the top and bottom shells, in particular in the region of the indentations. This can for example be realized by the gap between the (already assembled) upper and lower shell is flooded with a liquid containing the porous material of suitable viscosity such that the porous material settles in the desired thickness on the upper and lower shell, whereupon - After possibly necessary removal of excess liquid - the same under a suitable temperature effect on the upper and lower shell can be "firmly sintered".

Furthermore, it can be provided within the scope of the invention that the porous material at least partially, in particular in that region in which the porous material adjacent to the indentations on the interspace touches the porous material adjacent to the lower shell in the region of the respective recesses, from an originally pasty mass is prepared, which applied before assembly to corresponding areas of the upper and / or lower shell and after assembly of the upper and lower shell was solidified under the action of suitably high temperatures (with evaporation of liquid constituents). In this case, either the entire the upper and lower shell interspaces suitably covering and connecting porous material be prepared using a pasty mass in the above sense, on the other hand, only a partial use of a pasty mass in the above sense, in particular, can also offer, otherwise produced material layers of porous material, which are already formed on the lower and / or upper shell, while avoiding the formation of gaps or compressions to connect with each other.

A yet further preferred embodiment of the invention provides that the porous material is at least partially formed by at least one prefabricated molded part of porous material, which is attached before the assembly of upper and lower shell from below to at least one recess of the upper shell and is designed such that the molded part after assembly of the upper and lower shell on the space side, the at least one indentation and the lower shell contacted.

In this case, for example, a single molded part of porous material may be provided, which is plugged onto all indentations of the upper shell and each indentation and the lower shell - in the region of the respective indentation - connects. Furthermore, if appropriate, a separate molded part can also be provided for each indentation (or one group of indentations), which is attached to the relevant indentation (or the group of indentations) in the aforementioned sense. In this case, if necessary, areas of the lower and / or upper shell which are not contacted by the molded parts or any intermediate areas within the molded parts can then, for example, be filled with further porous material using a pasty mass in the above-mentioned sense. Furthermore, it can be provided in a particularly preferred manner within the scope of the present invention that the porous material contacting the upper and lower shell has a varying layer thickness and / or a varying porosity and / or varying pore diameter.

Since the layer thickness of the porous material has an influence on its absorption capacity and the evaporation rate given in a specific range, by varying the layer thickness of the porous material, specific areas of the lower and / or upper shell can be used for the evaporation of liquid working medium or the absorption of the condensing working medium be optimized. Further, by specific variation of the porosity or pore diameter of the - e.g. applied by different pasty masses - porous material which thereby adjusting capillary forces are specifically adapted to the desired liquid transport in the porous layer.

Since both underside cooling and underside-side heating of the vapor chamber can be provided in the context of the present invention, it is particularly advantageous if the abovementioned variation of the layer thickness and / or the porosity of the porous material takes into account the desired heat transport in both directions, by in the porous material - eg distributed in the region of each indentation or alternately across the vapor chamber - a first fluid path with improved liquid transfer properties from the top to the bottom shell and a second fluid path with improved liquid transport properties from the bottom to the top shell and / or with correspondingly improved ones Evaporation rate is created on the lower or upper shell.

The upper shell and / or the lower shell of a vapor chamber according to the invention can in principle be made of any suitable material with comparatively good thermal conductivity and sufficiently simple processability be made (eg made of silver), but are - also for cost reasons - particularly preferably made of copper or aluminum.

Preferably, the upper and lower shell of a vapor chamber according to the invention on a circumferential - advantageously in a plane - extending edge gas and liquid-tightly connected to each other, in particular welded and / or soldered.

Furthermore, it proves to be particularly advantageous if upper and / or lower shell-with the exception of webs optionally provided for stiffening purposes-have a layer thickness of less than or equal to 2 mm, more preferably of less than or equal to 1 mm. Preferably, the wall thickness can be realized as thin as possible, whereby, of course, taking into account the prevailing pressure within the vapor chamber, a sufficient mechanical stability still has to be ensured. Such thin layer thicknesses ensure a further improved heat transfer and a particularly low heat capacity and also in the

With regard to constructive aspects to be striven for particularly low weight of a vapor chamber according to the invention.

An upper shell with indentations suitable for the present purpose can e.g. be made by deep drawing from a suitable metal sheet. Furthermore, suitable for producing an upper shell suitable geometry, especially if this - which is particularly advantageous - should have a very small layer thickness of significantly smaller than 1 mm, also electro-galvanic manufacturing process, in particular the so-called "electrofor- ming".

In particular, the indentations of the upper shell acting as sample receptacles may be particularly preferably thin-walled (advantageously <1 mm, again advantageously <5 mm), since this - because of the so far low mass of the indentation bounding wall - a smaller Specific heat capacity in the immediate area of the sample to be tempered sample is achievable, whereby faster temperature changes are allowed.

In addition, it can be advantageously provided in the context of the present invention that the vapor chamber has at least one extending into the steam gap temperature and / or pressure sensor.

A temperature sensor extending into the steam gap proves to be advantageous, in particular, if its temperature measurement value is determined with the aid of a suitable monitoring and comparison unit (e.g.

continuously or at predetermined intervals) with that of a second temperature sensor, e.g. Bottom of the Vapor Chamber (i.e., in contact with the lower shell) is arranged.

Because the two measured temperature values of the arranged at different locations temperature sensors are in fixed relation to each other, so that - if there is a deviation so far - a malfunction of the vapor chamber can be reliably and quickly detected. Such a malfunction, which obviously can no longer be expected to result in proper tempering and, if necessary, destruction of possibly irretrievable samples, can, for example, be expected. be caused by a leak in the gas-tightness of the gap, which causes a possibly creeping change in the prevailing pressure conditions in the Vapor Chamber up to the loss of function.

In constructive terms, it proves to be particularly advantageous in a Vapor Chamber according to the invention, if at least one threaded blind hole is formed on the underside of the lower shell - for example in a specially reinforced area - to connect the Vapor Chamber on the underside by means of a screw connection with an adjacent component can. Finally, the present invention relates not only to a vapor chamber as such, which could in principle be used in a wide variety of devices - eg also in an incubator - but in particular also a thermocycler, which - for tempering samples with predefined temperature cycles - at least one heat sink, (At least) a preferred electric heating means (eg in the manner of a PTC element) and a vapor chamber of the type according to the invention and described above. For this purpose, all the aspects already mentioned apply in the same way, so that reference is made to avoid repetition.

Hereinafter, an embodiment of the present invention will be explained in more detail with reference to the drawing. It shows

1 shows an embodiment of a vapor chamber according to the invention together with an insertable therein microtiter plate in an exploded view,

Fig. 2 is a perspective - partially broken view - the

Vapor chamber of Fig. 1,

3 shows a sectional view through the vapor chamber from FIGS. 1 and 2 with a microtiter plate inserted therein according to the angled section line III - III from FIG. 2, FIG.

4 shows a perspective view of an embodiment of the essential components of a thermocycler according to the invention,

5 shows a representation for comparing the temperature homogeneity of a vapor chamber according to the invention with that of a sample holder body constructed of solid silver and FIG

Fig. 6-10 different representations of further embodiments of Vapor Chambers invention for use in a thermal cycler according to the invention with heating and cooling of the Vapor Chamber on the underside. 1 to 3 show an exemplary embodiment of a vapor chamber 1 according to the invention in various views, wherein in the perspective exploded view from FIG. 1 and in the sectional view from FIG. 3, a microtiter plate 2 insertable or inserted therein is shown in addition.

The vapor chamber 1 comprises a lower shell 3 made of copper and an upper shell 4 made of the same material, the upper shell 4 having on the upper side a plurality, in the present case a total of 96, recesses 6 distributed over its surface 5, which extend in the direction of the lower shell 3 extend. The indentations 6 act as sample receptacles into which samples 7 (see FIG. 3) to be tempered using the vapor chamber 1 can be introduced either directly or indirectly. However, lower shell 3 and upper shell 4 may also be made of other suitable materials, e.g. made of aluminum or silver.

In the present case, the (liquid) samples 7 to be tempered are accommodated in individual cavities or sample containers 8 of the microtiter plate 2, for which purpose the relevant sample 7 was filled into the respective sample container 8 through an opening 9 accessible from above. The samples 7 are introduced within the sample containers 8 which protrude downwards from the microtiter plate 2 - by placing the microtiter plate 2 in the correct position on the upper shell 4 adapted in terms of its geometry - into the recess 6 respectively associated with the respective sample 7. In this case, the sample containers 8 of the microtiter plate 2 with their respective outer side are in planar contact with the side wall of the indentation 6 in order to ensure good heat transfer.

Upper shell 4 and lower shell 3 are along a - the Vapor Chamber 1 completely encircling - edge 10 gas and liquid tightly connected to each other, which, for example, by a suitable welding and / or solder joint can be done. Within the intermediate space 11 formed between the upper shell 4 and the lower shell 3, a fluid working medium (not shown) is accommodated and, arranged like a layer on upper and lower shell 3, 4, a porous material 12, 13 which interacts with the fluid working medium in the sense of that it can absorb the liquid phase of the working medium and transport it using capillary forces. The fluid working medium can be introduced, for example, through a suitably closable access opening in the upper or lower shell into the intermediate space 11.

Between the lower and upper shell 3, 4 space-side covering porous material 12, 13 in the present case, the entire Vapor Chamber 1 penetrating steam gap 14 is formed, which in the present case between the two porous material layers 12, 13 and thereby inter alia - according to the in Fig 1. The entire line of indentations 6 of the upper shell 4 surrounds all indentations 6 of the upper shell 4, namely between the lateral boundary of the vapor chamber 1 and the indentations 6 arranged on the edge. In addition, each indentation 6 is simultaneously fully enclosed by the steam gap 14 surrounded circumferentially, as indicated by the two dashed lines 14 "in Fig. 2.

When the lower shell 3 is actively heated, the liquid phase of the working medium received in the adjoining layer of porous material 12 evaporates into the steam gap 14 by absorbing latent heat and is there due to a suitably adjusting pressure gradient in the direction of the colder upper shell 4 or the thereto trained indentations 6 transported. In this respect, it is advantageous for the desired temperature homogeneity in the region of the various indentations 6 that the steam gap 14 extends in three-dimensional and contiguous manner over the entire cross-sectional area of the vapor chamber 1 and thereby revolves the indentations 6, whereby the vapor phase also transversal or lateral can spread around the indentations 6 around. The working medium can then condense again with the release of latent heat in the region of the upper shell. There it is taken up by the porous material 13 arranged on the upper shell side. Because of the capillary force of the porous material 12, 13 and the connection of the upper and lower shell side arranged porous material 12, 13, at least partially - in the present case, however, in particular around each recess 6 around - there is, the condensed liquid phase of the working medium then again transported to the lower side region of the porous material 12, where it can evaporate again at not yet carried out temperature compensation.

By virtue of the fact that each indentation 6 within the interspace in the present case is completely surrounded by the at least one steam gap 14 of the vapor chamber 1, a particularly effective heating of the individual indentations 6 acting as sample holders - and thus also the samples 7 taken therein - can take place.

2 and 3 it can be clearly seen that in the present exemplary embodiment of the invention all indentations 6 of the upper shell 4 are in contact with the lower shell 3 in the region of their underside 15, in which region the layer of porous material 12 arranged on the underside is interrupted. A portion or all indentations 6 can there to increase the mechanical stability of the Vapor Chamber 1 - and to improve the heat transfer - be connected to the lower shell 3, in particular metallurgical manner.

On the lower shell 3 are - distributed over the lower shell 3 in a square pattern - a plurality of webs 16 are arranged, which are superior to the other layer thickness of the lower shell 3, which may be less than 2 mm or even less than 1 mm are selected, and thus cause a mechanical reinforcement of the structure of the lower shell 3.

Furthermore, the lower shell 3 on the underside a plurality of threaded blind holes 17, one of which in the sectional view of FIG. 3 recognizable. bar and which are used for fixed mounting of the Vapor Chamber 1 to an adjacent component, such as a heating and cooling element. In this area, the lower shell 3 also has a suitable reinforcement 18.

In the lower right portion of the section shown in Fig. 3 by the Vapor Chamber 1 two - for the introduction of a temperature sensor externally accessible - bores 19, 20 can be seen, of which a hole 19 is arranged close to the ground, while the other bore 20 within the Vapor Chamber 1 is located slightly higher and there extends into the space present in the gap 11 steam gap 14 or adjacent thereto. By means of temperature sensors (not shown) and suitable electronics, as already explained above, the correct functioning of the vapor chamber 1 can be monitored in order to control the temperature of the vapor chamber 1 in the event of a malfunction in order to avoid destruction of samples 7 in time - if necessary, automatically - to be able to switch off.

4 shows a perspective view of an exemplary embodiment of a thermal cycler 21 according to the invention, which in the present case has a layered construction with thermal coupling of the components adjacent to one another from below to better illustrate the components used for this purpose

a suitably sized heat sink 22,

a first flat vapor chamber 23 (without top indentations for sample taking),

a plurality of heating / cooling elements 24a, 24b, 24c (for example Peltier elements) as well as

a second arranged above the heating / cooling elements 24a, 24b, 24c Vapor Chamber 25 of the inventive design with on the upper side formed indentations 6 for receiving the temperature-controlled by means of the thermal cycler 1 samples

having. The heat sink 22 has a lamellar structure 26 on the underside, which provides a particularly large surface area for effective heat exchange between a cooling fluid (eg air) flowing between the lamellae in order to achieve a high cooling capacity.

The lower vapor chamber 23, which in the present case is mounted by means of a plurality of screw connections 27 between a mounting plate 28 and the upper side of the heat sink 22, provides excellent thermal contact between the heat sink 22 and the heating / cooling means 24a arranged in a recess of the mounting plate 28. 24b, 24c ago, in particular by providing a larger contact area for dissipating heat to the heat sink 22, as this would be given by the contrast significantly smaller surface area of the heating / cooling elements 24a, 24b, 24c. For the purpose of bolting the lower vapor chamber 23 to the heat sink 22 and the mounting plate 28, through-holes are provided in the vapor chamber for bolting purposes, such as these, e.g. are described in WO 2005/114084 A1.

Ultimately, however, it should be noted that the lower vapor chamber 23, although the thermal contact between heating / cooling elements 24a, 24b, 24c improved, but not necessarily must be present and - at the expense of a possibly. Slightly extending cooling of samples - also quite could be omitted, so in the present case only optional in the sense of a preferred embodiment of a thermal cycler according to the invention is provided.

Between heat sink 22 and lower vapor chamber 23 and the upper (inventive) Vapor Chamber in the present case a total of six each area designed heating and cooling elements 24a, 24b, 24c (eg Peltier elements) arranged in two adjacent rows of three each, the - depending on electrical wiring - for heating or cooling on the underside upper vapor chamber 25 or in the indentations 6 suitably introduced samples function.

The upper vapor chamber is constructed almost identically to that of FIGS. 1 to 3, so that reference can be made to the above explanations with regard to their mode of operation and the features relevant for this purpose. The only difference to the embodiment shown in FIGS. 1-3 is to be noted in this respect that the upper vapor chamber 25 in FIG. 4 has a thicker-walled upper shell 4, whereby here too at least the wall thickness of the space between the upper shell 4 and lower shell 3 inwardly extending indentations 6, which act as a sample holder, still thin - with a wall thickness of preferably less than or equal to 2 mm, even more preferably less than 1 mm - are configured.

Finally, FIG. 5 shows a diagram with measured values of comparative measurements in order to illustrate the significantly improved temperature homogeneity or uniformity of a vapor chamber according to the invention compared with the prior art.

A typical PCR cycle with temperature levels maintained at + 95 ° C, at + 55 ° C and at + 72 ° C was carried out - each with different and subsequently explained test setups.

The former temperature level at + 95 ° C was started by appropriate control of the heating / cooling means with a temperature rise rate of + 3 ° C / s (or 3 K / s) and then held for 10 seconds. Thereafter, the temperature in the sample holders was lowered at a rate of -1.5 K / s to + 55 ° C and held this temperature level for 10 seconds, after which a renewed heating at a rate of turn +3 K / s to + 72 ° C and then holding this temperature for 10 seconds. At the same time, by means of suitable temperature sensors, monitoring was carried out in a total of eight different samples. took adjusting temperature of the respective sample receiving body, each of which had 96 sample receptacles. The position of the sample recordings monitored by the temperature sensors can be taken from the schematic diagram drawn on the top right in FIG. 5, wherein said schematic diagram represents a plan view of the respective sample receiving body. The monitored sample recordings are indicated therein by black coloring.

Four of the monitored sample recordings thus corresponded to the sample recordings arranged on the corner of the sample receiving body. Two additional supervised specimens were approximately mid-side at the edge. And the last two supervised specimens were approximately centered in each of the left and right halves of the given array of a total of 96 specimens.

In the measurements, in each case in the last section of the temperature level held for 10 seconds, the temperature in all monitored sample recordings was determined three times in close succession, followed by the difference between the maximum value and the minimum value of the sample taking into account all measurements in the various sample recordings measured temperatures, which was defined herein as "uniformity" (uniformity) and was plotted on the y-axis of the bar graph in Fig. 5.

The measurements were carried out on the one hand on a thermocycler according to the invention of the type shown in FIG. 4 ("96 well 3D-VCM") and on the other hand on an arrangement known from the prior art, in which - compared with the arrangement of FIG - The upper Vapor Chamber 25 was replaced by a likewise 96 sample recordings sample body made of solid silver ("96 well Silvermount"), which in turn was mounted on the underside of a flat heat pipe, which made thermal contact with the underlying heating and cooling elements. The measurements show that the maximum temperature difference between the measured temperatures in the various sample receptacles in an inventive arrangement always (ie at all three approached temperature levels) is significantly lower than is the case in the known from the prior art arrangement. At the 95 ° C temperature plateau, it was only 0.25 K (compared to 0.49 Kelvin in the arrangement used in the prior art), at the 55 ° C temperature plateau only 0.13 K (compared to 0.26 K at the stand the technique used) and at the 72 ° C temperature plateau only 0.23 K (versus 0.31 K in the arrangement used in the prior art). It is apparent in the context of the present invention - in addition to the advantages explained in detail above - also a significantly improved temperature homogeneity in the simultaneous temperature control of a variety of samples.

FIGS. 6-10 show, to demonstrate different variants for introducing the porous material into the vapor chamber, various representations of further embodiments of vapor chambers 1 according to the invention for use in a thermocycler according to the invention with the vapor chamber 1 heated / cooled on the underside.

In this case, two superimposed representations are shown in FIGS. 6-9, of which in each case the upper shows a sectional view through a Vapor Chamber 1 according to the invention before its final assembly and the lower one shows a section through the finished vapor chamber 1.

Fig. 6 relates to an embodiment of the invention, in which - see the upper diagram - applied before the assembly of the vapor chamber both on the upper shell 4 and on the lower shell 3 each an intermediate space material layer 13, 12 of porous material and already under Temperature action, as described above, was solidified (in a kind of sintering process). The upper shell side provided material layer 13, which also covers the space-side surface of the recesses 6, However, at the indentations 6, it deliberately does not extend so far in the direction of its underside end that it would come into contact with the lower-shell-side material layer 12 when the vapor chamber 1 is assembled.

Rather, the porous material 30 is present in the area in which it adjoins both the indentations 6 and the lower shell 3 on the space side, made of an originally pasty mass 29, the bead before the assembly of the upper and lower shell 4,3 Area of pointing to the lower shell lateral ends of the recesses 6 is applied and solidified after assembly of the upper and lower shell 4, 3 under the action of suitably high temperatures.

The lower representation from FIG. 6-in particular the detail enlargement contained therein-shows well how the originally pasty mass 29 in the region in which the porous material 13, 30 adjoining the indentations 6 on the gap side surrounds the porous material adjoining the lower shell 3 12 touched, solidified and with each

adjacent material layers 12, 13, so that in the region of the respective indentations 6, a direct transport of the liquid phase of the working medium of the vapor chamber between the lower side and the shell side provided porous material 12, 13, 30 can take place.

7 shows a further embodiment of a vapor chamber according to the invention, in which (see the upper illustration) before assembly of the vapor chamber, both the upper shell 4 (and its indentations 6) and the lower shell 3 on the interspace with a pasty mass 29 containing the porous material was coated, so that - when assembling upper and lower shell - the two layers of pasty mass 29 come into contact with each other in regions and after a subsequent action of temperature in the already explained sense a total coherent inner coating of the vapor chamber 1 of porous material 30 ( see the lower illustration of Fig. 7) can form. Fig. 8 shows a further embodiment in which the upper and lower shell 4, 3 itself have no Vapor Chamber occlusive circumferential edge. Therefore, as can be seen in the upper illustration of Fig. 8, the upper shell 4 are joined to the lower shell 3, wherein still the space-side surfaces of the upper and lower shell 4, 3 are accessible from the outside and with a porous Material containing pasty mass 29 can be coated. Subsequently, the Vapor Chamber 1 can be closed by means of a separate, peripheral edge 31. Subsequently, a solidified layer of porous material 30 can then be produced under suitable temperature action from the pasty mass 29, as shown in the lower illustration of FIG. 8.

The exemplary embodiment illustrated in FIG. 9 relates to the possible use of prefabricated molded parts 32 which are designed in such a way that they can be attached from below to the indentations 6 of the upper shell 4 before the upper and lower shell 4, 3 are assembled , Wherein each molded part 32, after assembly of the upper and lower shell, contacts at least the indentation 6 and the lower shell 3.

For the sake of completeness it should be mentioned that even in the embodiment of FIG. 9, the underside 15 of each indentation 6, ie the side facing the lower shell of the bottom of the respective indentation 6 forming wall contacted the lower shell and after assembly of the Vapor Chamber advantageously metallurgical the lower shell is connected.

Finally, FIG. 0 shows a final exemplary embodiment of a vapor chamber according to the invention, in which first the upper and lower shells 4, 3, which have not yet been covered with porous material, are assembled, wherein for the introduction of the porous material into the intermediate space 11 an edge-side arranged opening 33 is provided, which can be closed fluid-tight with a lid 34. Through this opening 33, a liquid containing the porous material of suitable viscosity can then be introduced into the gap 11 so that the porous material settles in the desired layer thickness on the upper and lower shell, whereupon - after possibly necessary removal of excess liquid - the same can be "baked" under appropriate temperature effect on top and bottom shell.

Claims

claims

Vapor chamber (1) comprising a lower shell (3) and a

Upper shell (4), wherein between the lower shell (3) and upper shell (4) at least one gas and liquid-tight intermediate space (11) is formed, in which a fluid working medium

taken as well as one with the fluid working medium

cooperating porous material (12, 13, 30) is arranged, wherein the porous material (12, 13, 30) at least partially touches the upper shell (4) and / or the lower shell (3), but the at least one intermediate space (11). under formation of at least one cavity-like steam gap (14) does not completely fill,

wherein the upper shell (4) of the vapor chamber (1) on the upper side a plurality of over the surface (5) distributed, extending in the direction of the lower shell (3) and acting as a sample receiving indentations (6), in which

Use of the vapor chamber (1) samples to be tempered (7) can be introduced from above,

wherein at least one at least partially through the porous

Material (12, 13, 30) limited vapor gap (14) extends in such a three-dimensional manner that within the intermediate space (11) between the upper and lower shell (4), one or more indentations (6) of the upper shell (4) at least partially encircling laterally,

wherein at least a part of the on the upper shell (4) formed and extending in the direction of the lower shell (3)

Indentations (6), preferably all indentations (6), touching the lower shell (3) on the underside, wherein at least a part of the lower shell (3) contacting indentations (6) are connected on the underside with the lower shell (3),

wherein each indentation (6) of the upper shell (4) is contacted on the space side with the porous material (13, 30) and

wherein the porous material (13, 30) adjoining the indentations (6) on the space side contacts the porous material (12, 30) adjacent to the lower shell (3) in the region of the respective indentations (6).

Vapor chamber according to claim 1,

characterized,

that between the upper and lower shell (4, 3) at least one steam gap (14, 14 ') is provided, which circulates laterally outside all indentations (6) and within the space (11) between the lateral boundary of the vapor chamber (1). and the edge-arranged indentations (6) is formed.

Vapor chamber according to claim 1 or 2,

characterized,

that each indentation (6) is completely surrounded by at least one steam gap (14, 14 ").

Vapor chamber according to one of the preceding claims, characterized

in that the porous material (12, 13) is formed by at least two porous material layers (12, 13), of which a first material layer (13) lies on the outer shell (4) on the space side and a second material layer (12) on the space side on the outer side

Lower shell (3) is formed, wherein the first and second Material layer (12, 13) contact each other in some areas and in other areas to form the at least one

Steam gaps (14) are spaced apart.

5. Vapor chamber according to one of the preceding claims,

characterized,

the porous material (13, 30) adjoining the indentations (6) on the interspace side and the porous material (12, 30) adjoining the lower shell are contacted by the porous material (12, 13, 30) being in contact with the top surface. and lower shell (4, 3) as a whole contiguous

Inner coating of the vapor chamber (1) is formed.

6. Vapor chamber according to one of the preceding claims,

characterized,

that the porous material (30) at least partially, in particular in that area in which the

The porous material (30) which adjoins the indentations (6) on the indentations (6) touches the porous material (12) adjacent to the lower shell (3) in the region of the respective indentations (6), is made from an initially pasty mass (29), which is before Assembly of the upper and lower shell (4, 3) applied to corresponding areas of the upper and / or lower shell (4, 3) and after assembly of the upper and lower shell (4, 3) was solidified under the action of suitably high temperatures.

7. vapor chamber according to one of claims 1 - 4,

characterized,

that the porous material at least partially by at least one prefabricated molded part (32) of porous material is formed, which before assembly of upper and lower shell (4, 3) from below on at least one indentation (6) of the upper shell (4)

is attached and designed such that the molded part (32) after assembly of the upper and lower shell (4, 3)

the space side, the at least one indentation (6) and the lower shell (3) contacted.

8. Vapor chamber according to one of the preceding claims, characterized

in that the porous material (12, 13, 30) which contacts the upper and lower shell (4, 3) on the interspace side has a varying

Layer thickness and / or a varying porosity and / or varying pore diameter.

9. Vapor chamber according to one of the preceding claims, characterized

that upper and lower shell (4, 3) are made of copper or aluminum.

10. Vapor chamber according to one of the preceding claims,

characterized,

the upper and lower shell (4, 3) are connected to one another in a gas-tight and liquid-tight manner at a peripheral edge (10),

in particular welded and / or soldered, are.

11. Vapor chamber according to one of the preceding claims, characterized

that upper and / or lower shell (4, 3) with the exception of optionally provided for stiffening purposes webs (16) a layer thickness of less than or equal to 2 mm, more preferably of less than or equal to 1 mm.

12. Vapor chamber according to one of the preceding claims,

characterized,

the vapor chamber (1) has at least one temperature and / or pressure sensor extending into the steam gap (14).

13. Vapor chamber according to one of the preceding claims,

characterized,

that at least one of the underside of the lower shell (3)

Threaded blind hole (17) is formed to the Vapor Chamber (1) on the underside by means of a screw connection with a

to connect adjacent component.

14. Thermocycler (21) comprising

a heat sink (22),

at least one electric heating element (24a, 24b, 24c), which may also be advantageously suitable for cooling, and one above the at least one electric heating element (24a, 24b, 24c) arranged vapor chamber (1) according to one of the preceding claims.