DE102022109312A1 - Device for accelerated, miniaturized cooling and heating in medical technology - Google Patents

Abstract

The invention relates to a device for accelerated, miniaturized cooling and heating, in particular for PCR or mRNA analysis using thermocyclers for duplicating DNA or mRNA substances in medical technology To create heating in medical technology, which has a significantly improved service life, which enables a higher speed of the PCR or mRNA analysis and more precise temperature profiles and improves the accuracy of the temperature control. According to the invention, the novel device for accelerated, miniaturized cooling and heating in medical technology, a massive heat spreader plate 2 is formed, which consists of highly thermally conductive silver with the best performance. One or more heat pipes 5 arranged, embedded and soldered in the solid heat spreader plate 2 multiply the rapid heat distribution. In principle, it is also possible to arrange closed channels instead of the heat pipe(s) 5, in which a highly thermally conductive medium can circulate and ensure effective heat distribution. Of particular advantage is it all with

Description

The invention relates to a device for accelerated, miniaturized cooling and heating, in particular for PCR or mRNA analysis using thermocyclers for amplifying DNA or mRNA substances in medical technology.

A number of different arrangements for constructing ThermoCyclers are known. Again and again ideas for solutions for accelerated, miniaturized cooling and heating were published, without satisfying the desire for even higher speed and precision of the temperature curves and the exactness of the temperature control. In order to improve the speed of the PCR or mRNA analysis, as well as the associated production costs, numerous solutions have been developed and protected in the past. There are ULTRA FAST PCR devices that use extremely thin polypropylene tubes. Such can be found, for example, at https://www.intas-shop.com/de/thermocycler/next-genpcr.html on the Internet.

Another approach uses magnetic nano-particles to encapsulate the PCR or mRNA substance and to cool and heat it more quickly. This can be found at https://www.eurekalert.org/pub_releases/2020-12/ifbs-dohl20720.php.

The fastest temperature changes can also be achieved with circulating cold and warm liquids, as under EP 000002535427 A2 suggested.

In practice there is a lot of reluctance to use ULTRA FAST PCR devices. The use of Peltier elements for heating and cooling has established itself as the so-called gold standard, since this is the best way to control the temperature curves and the precision of the temperature control.

A well-known solution of the gold standard consists in the use of discrete Peltier elements, which are connected to the other separate components of the ThermoCycler using thermally conductive pastes or thermally conductive adhesives according to the prior art. For example, the EP 1 090 141 B1 a heating block and separate Peltier elements as well as a heat spreader plate.

So-called quadratic heat diffusers, known from the website https://www.quick-coolshop.de/en/heatdiffuser/heatdiffuser-quadratic/heat-diffuser-quadratic.html (Flähen-Wärmespreiz- plate) after the US8671570B2 . In contrast to heat pipes (heat pipes), a quadratic heat diffuser can distribute a thermal overheating point (hotspot) over the surface, which is particularly important for processors such as CPUs. Quadratic heat diffusers use hermetically sealed vapor chambers. However, hermetically sealed vapor chambers do not allow for any breakthroughs for attachments or vias in the quadratic heat diffusers.

A prerequisite for connecting a Peltier element and a heat spreader plate using soldering is that both components have surfaces that can be soldered. For this beats DE 4 329 816 A1 propose to provide the aluminum, which is often used for heat spreader plates, with an additional copper coating. This technical solution has the disadvantage that the coating can become detached during the life cycle of the ThermoCycler during the hundreds of thousands of temperature cycles required for the PCR or mRNA analysis and it becomes unusable relatively quickly.

It is also known that the Peltier elements, which are typically provided with ceramic plates with good thermal conductivity, are coated with gold or with graphite foils, as in DE 20 2012 009 977 U1 described, documented. However, this solution also has the disadvantage that the fragile coating can become detached during the life cycle of the ThermoCycler during the hundreds of thousands of temperature cycles required for the PCR or mRNA analysis. In addition, even ceramic plates with good thermal conductivity have a significantly poorer thermal conductivity than metals with good thermal conductivity.

From the technical solution according to the WO 2006/123190 A1 / EP 1 888 797 A1 non-oxidizing silver plates have already been described as heat spreader plates. The composition of this alloy Argentium consists of 93.5 - 95.5% Ag, 1 - 4.4% copper and 1% germanium.

The invention is based on the object of creating a device for accelerated, miniaturized cooling and heating in medical technology, which has a significantly improved service life, which enables a higher speed of the PCR or mRNA analysis and more precise temperature profiles and the exactness of the temperature control improved.

The object is achieved with the features of the preamble and the characterizing part of the first claim. Further advantageous refinements are described in the dependent references same subclaims described. According to the invention, a massive heat spreader plate 2 is formed in the novel device for accelerated, miniaturized cooling and heating in medical technology, which consists of silver with high thermal conductivity for the best performance. One or more heat pipes 5 arranged and embedded in the solid heat spreader plate 2 multiply the rapid heat distribution. In principle, it is also possible to arrange closed channels instead of the heat pipes 5, in which a highly thermally conductive medium can circulate and ensure effective heat distribution. The innovative use of a low-temperature solder and the fact that everything is connected by means of soldering connections that are easy to produce ensures a very high level of thermal conductivity.

First, the useful effect unfolds according to claim 1, 1 , by the solution according to the invention for the integration of Peltier element 1, massive heat spreader plate 2 and heat pipe 5 leads. Their thermal conductivity exceeds the state of the art of ceramic plates with good thermal conductivity by a factor of 12.

Secondly, the useful effect unfolds in that low-temperature solder (e.g. Bi57.6Sn42Ag0.4) has a significantly higher thermal conductivity of typically 40 W/m*K compared to 10 W/m*K (thermal paste) or thermal adhesive 5 W/m*K.

Thirdly, the useful effect unfolds in that the soldering creates a detachable connection in that the individual parts can be separated again without impairing the functionality by applying temperatures above the melting point of the solder (≈ 138°C). Operating temperatures of over 175° C. (Laird, TEC, Marlow) are permitted for the Peltier elements 1 . This enables a component change, e.g. in the event of failure or when the service life has been reached.

Fourth, the useful effect advantageously unfolds particularly well when several Peltier elements 1 arranged in close proximity to one another convey heat loss peaks with staggered heating and cooling via the integrated common heat spreader plate.

Fifth, the useful effect unfolds in that, in contrast to the full-surface quadratic heat diffuser, the letting of heat pipes into the heat spreader plate allows the design of surfaces which are suitable for openings 3 and 4 for fastening (screws) or electrical connections.

Sixth, the useful effect unfolds in that, depending on the design, the miniaturization can be reduced by more than a factor of three of the usual size or the available thermal power can be increased by more than a factor of three with the same space requirement, i.e. the power density increases by more than the factor of three.

Seventh, the useful effect unfolds in that an elastic silicone mat with a negative impression of the overall arrangement is used during the soldering, which leads to a significant reduction in the effort involved in production, particularly in the case of a field of Peltier elements 1 .

Eighth, the useful effect also unfolds when the base plate 9 of the Peltier element 1 consists of another solderable material (e.g. copper, bronze) apart from the non-oxidizing silver mentioned in claim 1. In this case, the best performance is not available, but the material costs are lower. The best performance results when both the base plate 9 and the cover plate of the Peltier element 1 are made of non-oxidizing silver.

The essential solution approach of the present device according to the invention consists in the development of the solderability of Peltier elements 1 known from the prior art, solid heat-spreading plates and heat pipes. The temperature required for soldering must be in the temperature range between the maximum permissible operating temperature of Peltier element 1 and heat pipe 5 on the one hand and the melting point of the low-temperature solder on the other. The resulting detachable connection offers the new advantageous features described. Of particular advantage is the significant increase in the speed of the PCR or mRNA analysis, as cooling and heating during the amplification of the sample substances is possible at shorter time intervals with more precise temperature control. In addition, for the first time there is the possibility of through-plating in the quadratic heat diffuser.

• 1 eine Vorrichtung mit einem Peltier-Element 1
• 2 eine Vorrichtung mit mehreren Peltier-Elementen 1

Den schematischen Aufbau der erfindungsgemäßen Vorrichtung zum beschleunigten, miniaturisierten Kühlen und Heizen stellt 1 dar. 1 zeigt eine Vorrichtung zum beschleunigten, miniaturisierten Kühlen und Heizen nach Anspruch 1 mit Ergänzungen nach den Ansprüchen 2 bis 7. Das Peltier-Element 1 besitzt eine Grundplatte 9 aus nicht oxydierendem Silber. Die Peltier-Element-Grundplatte ist per Lötung mit der Wärmespreiz-Platte 2 verbunden. Die Wärmespreiz-Platte 2 enthält Aussparungen zur Aufnahme von Wärmerohren 5 und 6 zur Verteilung der Abwärme des Peltier-Elementes 1 über die größere Fläche der Wärmespreiz-Platte 2. Zwischen den Wärmerohren 5 und 6 gibt es Flächen welche für Durchführungen 3 und 4 zur Befestigung oder Kontaktierungen auf die Gegenseite des Peltier-Elementes 1 genutzt werden können. Weitere Flächen zwischen den Wärmerohren 5 und 6 können für ggf. bei individuellen Applikationen erforderliche weitere Durchbrüche 7 reserviert werden. In 1 sind die Anschlussfahnen 8 des Peltier-Elementes 1 in der Nähe des Durchbruchs 4 dargestellt. Unterhalb des Peltier-Elementes 1 befinden sich die Wärmespreiz-Platte 2 und eine oder mehrere Wärme-Rohre 5, 6 in unmittelbarer Nähe, so dass diese Elemente in einem Lötvorgang miteinander eine lösbare Verbindung erhalten können.The device according to the invention is based on the 1 their effect will be explained in more detail.

• 1 a device with a Peltier element 1
• 2 a device with several Peltier elements 1

The schematic structure of the device according to the invention for accelerated, miniaturized cooling and heating 1 represent. 1 shows a device for accelerated, miniaturized cooling and heating according to claim 1 with supplements according to claims 2 to 7. The Peltier element 1 has a base plate 9 made of non-oxidizing silver. The Peltier element base plate is connected to the heat spreader plate 2 by soldering. The heat spreader plate 2 contains recesses for receiving heat pipes 5 and 6 for distributing the waste heat from the Peltier element 1 over the larger surface of the heat spreader plate 2. Between the heat pipes 5 and 6 there are surfaces for bushings 3 and 4 for attachment or contacts on the opposite side of the Peltier element 1 can be used. Additional areas between the heat pipes 5 and 6 can be reserved for additional openings 7 that may be required for individual applications. In 1 the terminal lugs 8 of the Peltier element 1 are shown in the vicinity of the opening 4. Below the Peltier element 1 are the heat spreader plate 2 and one or more heat pipes 5, 6 in the immediate vicinity, so that these elements can be connected to one another in a detachable manner in a soldering process.

If necessary, the invention and 6 can be scaled so that several Peltier elements or a field of Peltier elements can be placed above the course of the heat pipes 5, 6, as in 2 shown. For its part, the heat spreader plate 2 can be mounted in a conventional manner on conventional, known heat sinks in order to dissipate the waste heat.

Reference List

1

Peltier element

2

heat spreader plate

3

Breakthrough for attachment and contacting to the opposite side

4

another opening for fastening and contacting the other side

5

heat pipe

6

another heat pipe

7

Reserved space for further attachments and contacts to the opposite side

8th

Terminal lugs of the Peltier element

9

Solderable base plate of the Peltier element

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 000002535427 A2 [0004]
• EP 1090141 B1 [0006]
• US8671570B2 [0007]
• DE 4329816 A1 [0008]
• DE 202012009977 U1 [0009]
• WO 2006/123190 A1 [0010]
• EP 1888797 A1 [0010]

Claims (7)

Device for accelerated, miniaturized cooling and heating in medical technology by means of a Peltier element (1) using a heat spreader plate , characterized in that a massive heat spreader plate (2) is arranged under the Peltier element (1), in which Heat spreader plate (2) one, two or more closed channels or thermally coupled heat pipes (5) are arranged, the heat spreader plate (2) is connected directly to a base plate of the Peltier element by means of a low-temperature solder, the heat spreader plate on the hot and/or cold side of the heat spreader plate is made of non-oxidizing silver plates, or the hot or cold plate sides are coated with non-oxidizing silver layers and are connected by means of a soldered connection while exploiting permissible temperature limits. Device for accelerated, miniaturized cooling and heating claim 1 , characterized in that a plurality of Peltier elements arranged in close proximity are connected to a common solid heat-spreading plate (2) by a soldered connection. Device for accelerated, miniaturized cooling and heating claim 1 or 2 , characterized in that heat pipes are embedded in the heat spreader plate and are arranged thermally connected to the Peltier elements (1) and the heat spreader plate by means of a soldering process. Device for accelerated, miniaturized cooling and heating claim 1 , characterized in that the heat spreader plate (2) has additional surfaces in which individually selectable openings (3) are arranged with and without a thread for mechanical attachment. Device for accelerated, miniaturized cooling and heating claim 1 , characterized in that the heat spreader plate (2) has surfaces in which individually selectable openings (4) are arranged for electrical contacting from the opposite side. Device for accelerated, miniaturized cooling and heating claim 1 , characterized in that an elastic silicone mat can be arranged for positioning and pressing during the soldering process, which forms a negative impression of the overall arrangement of Peltier elements (1), heat spreader plate (2) and, if necessary, the openings (3) for fastening elements and / or breakthroughs (4) for Kontaktierelemente5 contains. Device for accelerated, miniaturized cooling and heating claim 1 , characterized in that the base plate of the Peltier element (1) consists of a solderable material other than non-oxidizing silver.

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