Heat pipe and method of fitting a heat pipe

Abstract

The present invention relates to a heat pipe (1) for a preferably electric or electronic arrangement (2), preferably in the form of a printed circuit board, comprising an elongate, hermetically sealed hollow body (101), preferably in the form of a hermetically sealed tube, wherein a heat transport medium (112) is located in the interior of the hollow body (101). The heat pipe (1) also comprises at least one stamp region (103, 104) which narrows the cross section of the hollow body (101), wherein the stamp region (103, 104) forms an anchoring base for at least one contact pin (105), preferably for a group of contact pins (105).

Description

[0001] Heat pipe and method for assembling a heat pipe

[0002] The present invention relates to a heat pipe, which is preferably used in circuit-based systems. Furthermore, the present invention relates to a method for assembling a heat pipe.

[0003] A heat pipe according to the present invention is a two-phase heat conductor in the form of a hermetically sealed, tubular hollow body, preferably a metal hollow body, which conducts heat even over long distances with low thermal resistance. Heat is absorbed at one end of the heat pipe (evaporator side) and released to the environment at the other end (condenser side). Depending on the temperature range of the application, various fluids are used as the heat transfer fluid inside the hollow body, e.g. water, methanol, or helium (for low-temperature applications), or lithium or silver for high-temperature applications. A heat pipe can have a round, rectangular, or flat cross-section. A heat pipe can be rod-shaped, curved, or even bent multiple times. The inner wall of the hollow body has an internal structure that creates a capillary effect.This can be an inserted mesh layer, grooves or sintered material or a combination of these.

[0004] Printed state of the art

[0005] JP 2008-283154 A describes a heat pipe that is already equipped with a press-fit pin for press-fitting to a substrate equipped with a via. The heat pipe and the press-fit pin can be formed as a single piece. Alternatively, the heat pipe and the press-fit pin can be separate. In this case, an upper end area of ​​the press-fit pin must be completely wrapped around the outside of the heat pipe and then welded, screwed, or clamped to it. This type of connection causes insufficient heat transfer from the press-fit pin to the heat pipe. Furthermore, the described heat pipe is unsuitable for an automated assembly process.

[0006] Object of the present invention

[0007] The object of the present invention is to provide an improved heat pipe. Furthermore, an improved method for assembling a heat pipe is to be created.

[0008] Solution to the task

[0009] The object is achieved by a heat pipe having the features of claim 1 and a method according to claim 17. Advantageous embodiments of the invention are claimed in the dependent claims.

[0010] According to the invention, the heat pipe comprises at least one embossed region that narrows the cross-section of the hollow body. The surface of the embossed region forms a stable anchoring base for at least one contact pin, preferably for a group of contact pins. The hollow space of the heat pipe is constricted in the embossed region. Due to the anchoring of the respective contact pin in the embossed region, on the one hand, improved heat transfer between the contact pin and the heat transfer fluid can be achieved. On the other hand, the rigidity of the heat pipe achieved by the embossed region can be used to select the assembly sequence, according to which the respective contact pin is first pre-fixed to the electrical or electronic arrangement (preferably, for example, on a circuit board) and the heat pipe is then applied to the at least one contact pin and fixed thereto.This procedure is also possible with a group of contact pins pre-attached to an array. The invention therefore enables simple, reliable, and automated assembly while simultaneously ensuring good heat transfer. Furthermore, the invention ensures the advantage that existing, established, and certified contact pin assembly processes do not require intervention or modification of the equipment and machines used.

[0011] According to an advantageous embodiment, the embossed area for the at least one contact pin has a through-hole that serves to fix the at least one contact pin by means of a press fit. This enables automated clamping or pressing of the heat pipe with the respective pre-positioned contact pin.

[0012] Preferably, the through-hole is a punched hole. The through-hole positioned in the embossed area allows for the reliable anchoring of a contact pin to the heat pipe, with a non-embossed area of ​​the heat pipe's hollow body adjoining both sides of the embossed area.

[0013] According to an advantageous embodiment, several embossed areas, preferably spaced apart from one another, can be arranged along the hollow body. This allows heat to be transported by means of a single heat pipe across various locations within an assembly, preferably a printed circuit board assembly.

[0014] According to an advantageous embodiment, inner opposing wall regions of the hollow body can touch each other in the embossed region of the hollow body. The opposing wall regions of the hollow body “double” 1and therefore form an effective mechanical basis for anchoring the contact pins on the one hand, and on the other hand they ensure improved heat transfer into the heat pipe.

[0015] Preferably, a group of contact pins can be arranged in the embossed area. This can further improve heat transfer.

[0016] Preferably, inside the hollow body, preferably on its inner wall, there is a surface-enlarging structure, preferably in the form of a mesh-like or fabric-like structural insert or in the form of a sintered material applied to the inner wall, or a combination of both. This structure causes a capillary effect and supports the return transport of the condensed heat transfer medium to the area of ​​the heat source. At the embossed area, these areas touch one another and / or are pressed against the wall of the hollow body or are pressed onto the wall of the hollow body by the embossing, whereby the heat transfer via the at least one contact pin into the heat pipe and the heat transfer medium can be further improved. This applies particularly to cost-effective structural inserts, since these are loosely inserted and only have loose contact with the wall of the heat pipe at a few points.Instead, the embossed area results in a force and form fit, which improves the heat transfer at the crucial point of heat extraction and heat input into the heat pipe.

[0017] Preferably, the surface-enlarging structure is a fine-meshed copper mesh. Preferably, the hollow body is a copper tube.

[0018] According to an advantageous embodiment, the hollow body of the heat pipe can be deformed on both sides toward the center in the embossing area, relative to the cross-section of the hollow body, or in particular, can be designed with mirror symmetry. This is advantageous with regard to symmetrical material loading during embossing and the symmetry of the resulting bending of the material of the hollow body.

[0019] According to an alternative design, the embossed area can also be mirror-asymmetrical when viewed in the cross-section of the hollow body. This creates additional surface contact to further improve heat transfer between the heat pipe and the system (heat source or sink). This also shortens the heat transfer path through the contact pin, thereby reducing thermal resistance.

[0020] Preferably, the hollow body of the heat pipe adjoining the embossed area does not protrude beyond the embossed area towards the underside.

[0021] According to an advantageous embodiment, the underside of the hollow body can be flat even in its unembossed area. This allows additional surface contact to be created, regardless of any asymmetry of the hollow body in the embossed area, to improve heat transfer between the heat pipe and the system (heat source or sink).

[0022] According to an advantageous embodiment, the embossed region can divide the hollow body into a first region and a second region. This is advantageous because the transferred heat is distributed between the two regions and can be supplied from there to the main region, i.e., the region of the hollow body not encompassed by the embossed region. This also stiffens the heat pipe, which can further increase its mechanical stability.

[0023] According to an advantageous embodiment, the first region and the second region can be hermetically separated from the through-hole and thus from the exterior of the heat pipe. This prevents leakage of the heat transfer medium in the area of ​​the through-hole or the pressed-in contact pin.

[0024] The two areas can advantageously be defined by a material connection of the inner wall areas opposite the embossing area.

[0025] A welded joint, e.g. a resistance welded joint, can be provided as a material-to-material connection.

[0026] According to an advantageous embodiment, several embossed areas, each with at least one contact pin or with a group of contact pins, can be arranged along the hollow body of the heat pipe. This allows for heat coupling or heat tapping at various points along the heat pipe.

[0027] According to an advantageous embodiment, a plurality of contact pins can be arranged on a stamping area in a preferably straight row and / or with identical spacing from one another and / or in a preferably uniform surface pattern. This allows a good mechanical hold of the heat pipe with optimal heat transfer into the heat pipe during automated assembly. According to an advantageous embodiment, the at least one contact pin can be designed as a press-fit pin and have a bulging or an EON (so-called "eye of a needle") press-in area or the like for fastening the press-fit pin in a through-hole (via) or in a blind via of an arrangement, in particular a printed circuit board arrangement. Due to the spring-loaded press-in area, the press-fit pin can be effectively pressed into the hole or blind hole and thus securely anchored.

[0028] Alternatively, the at least one contact pin can be designed as a solder pin. This can also thermally connect a through-hole or blind hole of the assembly to the embossed area of ​​the heat pipe (without using a press-fit area). Alternatively, the solder pin can also be soldered to the top side of a circuit board or substrate using SMD technology.

[0029] This can also thermally connect a through-hole or blind hole in the assembly to the heat pipe's embossed area (without using a press-fit area). Alternatively, the solder pin can also be soldered to the top surface of a circuit board or substrate using SMD technology.

[0030] Alternatively, the at least one contact pin can be configured as a leadframe pin. In this case, the leadframe pin can be arranged on a so-called leadframe or be an integral part of such a leadframe. Thanks to the leadframe pins, the leadframe can thus be easily coupled, preferably automatically, to at least one heat pipe not only for electrically contacting an electronic component, but also for effective heat dissipation. Depending on the space requirements, the leadframe pins can be arranged in the same or opposite orientation, or parallel or perpendicular to the main extension plane of the component.

[0031] According to an advantageous embodiment, the respective contact pin can have a long (i.e., elongated) connection area, by means of which the embossed area of ​​the heat pipe can be fixed, in particular pressed, to the contact pin. This enables simplified automation of the heat pipe assembly.

[0032] According to an advantageous embodiment, the elongated connection area can be conical or truncated pyramid-shaped. In this case, the connection area of ​​the contact pin can widen towards the side of the arrangement. Due to the conical or truncated pyramid-shaped shape of the connection area of ​​the contact pin, the fit between the connection area and the through-opening of the embossed area of ​​the heat pipe changes from a loose fit to a press fit when plugged in. The conical or truncated pyramid-shaped shape of the elongated connection area thus enables advantageous pressing of the contact pin with the embossed area by first plugging the embossed area of ​​the heat pipe onto the respective contact pin (which has preferably already been connected to the arrangement beforehand) and then pushing the contact pin through.The pushed-through conical or truncated pyramid-shaped connection area can then be grasped and pulled further, allowing the contact pin to be pressed into the embossed area of ​​the heat pipe without any force adversely affecting an existing mechanical connection between the respective contact pin and the assembly. The angle of inclination of the cone or truncated pyramid can be less than 5°, preferably less than 2°, relative to the longitudinal axis of the contact pin.

[0033] According to an advantageous embodiment, the contact pin can comprise a gripping projection for a preferably automated gripping tool of a robot or an assembly unit. The gripping projection can advantageously be located between the press-in area and the elongated connection area of ​​the contact pin. The gripping projection can be implemented, for example, by a projection located above the press-in area of ​​the contact pin on the side opposite the assembly or on the side of the heat pipe.

[0034] According to an advantageous embodiment, the at least one contact pin can protrude from the stamped area on the side of the contact pin opposite the assembly when the heat pipe is assembled. This creates a certain amount of heat dissipation into the environment at the stamped area. Furthermore, the protruding portion of the contact pins can be used to mount the heat pipe onto the contact pins, ensuring low mechanical stress on the already mounted press-fit zones, for example, in the circuit board assembly.

[0035] The present invention further relates to a method for mounting a heat pipe according to claims 1 to 16 on an electrical or electronic arrangement with the following method steps:

[0036] - Providing an electrical or electronic arrangement, preferably a printed circuit board arrangement, preferably with at least one blind hole, in particular in the form of a blind via, or a through-hole, in particular in the form of a via (vertical interconnect access or through-hole or PTH (plated through hole) or an SMD printed circuit board arrangement,

[0037] - Press-fit assembly, preferably automated, of the at least one contact pin in the blind hole or in the through-hole, or

[0038] - Solder pin assembly, preferably automated, of the at least one contact pin in the blind hole or in the through-hole or on the SMD circuit board arrangement,

[0039] - Attaching the embossed area of ​​the heat pipe to at least one pre-assembled contact pin or vice versa, as well as

[0040] - Pressing the contact pin with the embossed area of ​​the heat pipe by applying a force in the axial direction of the contact pin.

[0041] The present invention further relates to a method for mounting a heat pipe according to claims 1 to 16 on an electrical or electronic arrangement with the following method steps:

[0042] - Providing, preferably automated, an electrical or electronic arrangement, wherein the electrical arrangement comprises a leadframe with at least one leadframe pin as a contact pin, - Attaching, preferably automated, the embossed area of ​​the heat pipe to the leadframe pin or vice versa, and

[0043] - Pressing the contact pin with the embossed area of ​​the heat pipe, preferably automated, by applying a force in the axial direction of the contact pin.

[0044] According to an advantageous embodiment, the heat pipe's embossed area can be attached to the elongated connection area of ​​the pre-assembled contact pin, or vice versa, with a loose fit and thus, in particular, without force being applied, i.e., without transferring any force to the contact pin. The contact pin protrudes on the side of the heat pipe's embossed area facing away from the assembly. This allows the contact pin to be gripped there using a gripper.

[0045] According to an advantageous embodiment, the contact pin can be pulled through in a direction opposite to the arrangement, whereby the contact pin and the embossed area of ​​the heat pipe are connected to each other in a press fit. This advantageously prevents any adverse impairment of the existing mechanical connection between the contact pin and the arrangement connected to the latter.

[0046] According to an advantageous embodiment, individual process steps or all process steps of the assembly of a heat pipe described above can be automated.

[0047] Description of the invention based on exemplary embodiments

[0048] Exemplary embodiments of the present invention are explained in more detail below with reference to the drawings. Identical features are provided with a reference numeral only once for the sake of clarity. They show: Fig. 1 shows a circuit board with a heat pipe according to the present invention in a sectional view;

[0049] Fig. 2 shows the heat pipe according to Fig. 1 in perspective view;

[0050] Fig. 3 an enlarged cross-sectional view of the hollow body of the Heat

[0051] Pipe in section plane AA of Fig. 2;

[0052] Fig. 4 is an enlarged cross-sectional view of the hollow body of the heat pipe in the section plane BB of Fig. 2;

[0053] Fig. 5 is an enlarged cross-sectional view of an alternative embodiment of a heat pipe in a section plane corresponding to section plane BB of Fig. 2;

[0054] Fig. 6 is an enlarged side view of a first example of a contact pin of the present invention in the form of a press-fit pin;

[0055] Fig. 7 shows the arrangement according to Fig. 1 before pressing the heat pipe with the contact pins previously inserted into the electronic arrangement;

[0056] Fig. 8 is an enlarged side view of a second example of a contact pin of the present invention in the form of a solder pin;

[0057] Fig. 9 a perspective view of a leadframe with contact pins designed as leadframe pins and

[0058] Fig.10 shows an exemplary arrangement of the leadframe of Fig. 9 with several heat pipes and a circuit board in exploded view.

[0059] Fig. 1 shows an electrical or electronic arrangement 2 in the form of a printed circuit board 201 carrying a plurality of electronic components 205. The printed circuit board 201 comprises a substrate 202, to the top and bottom of which conductor tracks 203 and 204 are applied, e.g., printed or structured by PCB wet etching. The substrate 202 is typically an insulator. The printed circuit board 201 can, as shown in Fig. 1, be single-layered or comprise multiple layers of substrate 202 and conductor tracks 203, 204.

[0060] In order to dissipate heat generated in the area of ​​the components 205 from the arrangement 2, a heat pipe 1 is connected to the arrangement 2 to form a thermal bridge. The heat pipe 1 comprises a tubular hollow body 101, to the end of which a heat sink 116 provided with individual cooling fins can be attached, e.g., shrunk on. Instead of a shrunk-on heat sink 116, a water-cooled "cold plate" or other heat sink (e.g., housing components or circuit board areas with low power dissipation densities) can also be contacted in the thermal system, for example, by a conventional heat pipe clamp connection or by a connection using contact pins according to the present invention. The heat pipe 1 serves to absorb heat generated in the area of ​​the components 205 and to supply it along the hollow body 101 to the heat sink 116. As a result, the arrangement 2 can be effectively cooled without a cooler integrated into the latter.

[0061] The heat pipe 1 comprises a plurality of contact pins 105 which, according to the embodiment of Fig. 1, are designed in the form of press-fit pins and of which only one is visible in the partial sectional view of Fig. 1. The respective contact pin 105 is pressed into a contact opening 206 in arrangement 2. The contact opening 206 is designed with a conductor coating 207 as a through-hole (also referred to as "PTH" or "Plated Through Hole"). As an alternative to a through-hole, the contact opening 206 can also be a blind via (not shown in Fig. 1). The contact pin 105 is mechanically connected, i.e. pressed, to the arrangement 2 by means of the press-in region 107 of the contact pin.

[0062] The heat pipe 1 comprises a stamped area 103, which serves as an anchoring base for the contact pins 105 in the hollow body 101. For this purpose, the hollow body 101 of the heat pipe 1 is constricted at the stamped area 103 and accommodates the contact pins 105 in this area. By means of the contact pins 105 in the stamped area 103, heat can be dissipated from the assembly 2 into the heat pipe 1 and directed to the heat sink or heat sink 116. Instead of a round cross-section, the hollow body 101 can also have a rectangular or flat cross-section. The heat pipe 1 can be rod-shaped or curved, or even bent multiple times.

[0063] For illustrative purposes, the proportions of assembly 2, i.e., the circuit board, and heat pipe 1 are shown somewhat distorted in Fig. 1. The dimensions and surface area of ​​assembly 2 are actually larger than the dimensions of heat pipe 1.

[0064] Fig. 2 shows the heat pipe 1 of the arrangement from Fig. 1 in a perspective view. The heat pipe 1 shown in Fig. 2 has a curvature in its hollow body 101 between the heat sink 116 and the area of ​​the contact pins 105. The curvature is system-specific with regard to the installation space, i.e. it does not have to be provided. In the embossed area 103 of the heat pipe 1, the contact pins 105 are arranged one after the other in a row with a constant spacing. The contact pins 105 protrude from the heat pipe 1 on the side of the embossed area 103 opposite the respective clamping area 107 or the arrangement 2. This allows the heat pipe 1 to be easily mechanically gripped, e.g. during an assembly process, or easily mechanically gripped, i.e. pulled off a circuit board, during a recycling process. In addition, this already dissipates a certain amount of heat upwards during operation.

[0065] The front end of the heat pipe 1 comprises a closure 117, which is produced, for example, by a cut through the hollow body 101 and subsequent wedge pressing. The inner walls of the hollow body 101 can also be materially connected to one another in the area of ​​the closure 117. This can be achieved, for example, by welding.

[0066] Fig. 3 shows the heat pipe 1 in the sectional plane AA of Fig. 2. The heat pipe 1 is filled with a heat transport medium, e.g. in the form of water, acetone, alcohol, ammonia or fluorinated hydrocarbons, inside its hollow body 101. Furthermore, a surface-enlarging, preferably porous structure in the form of a net-like or fabric-like structural insert 102 is arranged on the inner wall of the hollow body 101. The structural insert 102 causes a capillary effect and supports the return transport of the heat transport medium condensed in the area of ​​the heat sink 116 to the area of ​​the heat source or the contact pins 105. Instead of a net-like or fabric-like structural insert 102, a sintered material applied to the inner wall of the hollow body 101 can also be provided for this purpose.A combination of a net-like or fabric-like structural insert 102 and a sintered material applied to the inner wall of the hollow body 101 is also possible.

[0067] The mesh-like or fabric-like structural insert 102 is preferably made of copper. The hollow body 101 of the heat pipe 1 is also preferably made of copper.

[0068] Fig. 4 shows an enlarged cross-sectional view of the hollow body 101 of the heat pipe 1 in the section plane BB of Fig. 2. In the embossed area 103, opposing inner wall regions 108, 109 of the hollow body 101 lie directly against one another and thus double the wall thickness of the hollow body 101 at this point. This ensures, on the one hand, a stable mechanical basis for anchoring the respective contact pins 105. On the other hand, the heat transfer from the contact pin 105 via the "doubled" material of the hollow body 101 to the heat transfer medium 112, which is located in the two regions 114, 115 formed by the embossed area 103, is also improved.

[0069] In the embossing region 103, the hollow body 101 of the heat pipe 1 is deformed such that, in a central region, opposite inner wall regions 108, 109 of the hollow body 101 lie directly against one another or are pressed together. In this case, the structural insert 102 can be pressed together with the wall regions 108, 109. The opposite inner wall regions 108, 109 are additionally connected to one another by a material-to-material bond, so that a hermetic seal of the interior of the heat pipe 1 is achieved in this region and no heat transfer medium 102 can pass through this material-to-material bond. Preferably, a welded connection, e.g., a resistance welded connection, can be provided as the material-to-material bond. Due to the deformation caused by the embossing process, the heat pipe 1 comprises a first region 114 and a second region 115 located opposite one another horizontally.The first and second regions 113, 114 are connected to the hollow body 101. In the region of the adjacent inner wall regions 108, 109, a through-opening 106 is inserted to accommodate the respective contact pin 105 with its elongated connecting region 110. To ensure that the heat pipe 1 is pressed onto the respective contact pin 105, the latter has a slightly conical shape. The inclination angle a of the cone is a maximum of 5°, preferably a maximum of 2°. To connect the heat pipe 1 and the respective contact pin 105, each contact pin 105 has the elongated connecting region 110, which penetrates the through-opening 106 and, due to the conical shape of its connecting region 110, enables clamping or pressing.

[0070] Slightly above the press-in area 107 of the contact pin 105 there is a radially projecting gripping projection 111 for a preferably automated handling device, by means of which the arrangement of the contact pins 105 can be brought into position with respect to the arrangement 2, e.g. with respect to the printed circuit board 201, and can be pressed together with the latter.

[0071] In the embodiment of the heat pipe 1 shown in Fig. 4, the hollow body 101 is deformed toward the center on both sides of its embossed region 103, so that the opposite inner wall regions 108, 109 are subject to essentially identical deformation. The embossed region 103 has a mirror-symmetrical shape when viewed in cross-section.

[0072] According to the alternative embodiment shown in Fig. 5, the embossed area 104 can also be designed such that a flat support surface is created on the underside 113 of the hollow body 101. The embossed area 104 can further be designed such that the hollow body 101 of the heat pipe 1 does not protrude downwards. This embodiment shown in Fig. 5 ensures the additional effect that a particularly large amount of heat can be transferred via the flat underside 113 of the hollow body 101. Thus, a part of the wall of the hollow body 101 participates in the heat transfer. The heat transport path through the contact pin is also shortened and the thermal resistance is thereby reduced. In the embodiment according to Fig. 5, the inner wall areas 108, 109 touch below the hollow body 101 in the same way as was described with reference to Fig. 4. This area also comprises a through-opening 106 into which a contact pin shown in Fig.5 contact pin 105 not shown engages.

[0073] Fig. 6 shows an example of a contact pin 105 in an enlarged side view. On the underside of the contact pin 105 is the press-in area 107, which enables the contact pin 105 to be securely fixed in a receiving opening by deforming the material of the press-in area 107. The press-in area 107 can, for example, be bulged and contain a recess 118 in its inner area. Other shapes are also possible, such as slotted press-in zones (also called "eye of a needle" (EON)) or other resilient geometries. The latter enables plastic deformation to achieve the press-fit connection. As can be clearly seen from Fig. 6, the connection area 110 of the contact pin 105 is slightly conical, with the angle of inclination α being a maximum of 5°, preferably a maximum of 2°.The contact pin 105 preferably consists of a highly conductive and mechanically stable material, preferably comprising brass or copper.

[0074] For the automated handling of the contact pin 105, the latter comprises the gripping projection 111 above the press-in area 107, for example in the form of a laterally projecting projection, e.g., a ring projection, which a production robot or the like can engage.

[0075] The method according to the invention for mounting the heat pipe 1 on an electrical or electronic arrangement 2 is described in more detail below with reference to Fig. 7.

[0076] In a first step, an electrical or electronic arrangement 2, preferably in the form of a printed circuit board arrangement, is provided, preferably in an automated manner, in which at least one contact opening 206, e.g. in the form of a blind via or in the form of a through-hole (plated through hole or PTH), is provided.

[0077] Subsequently, a press-fit assembly or solder pin assembly, preferably automated, of the at least one contact pin 105 is performed such that it is secured in the contact opening 206 of the printed circuit board assembly via its press-in area 107, i.e., pressed or soldered via its contact area. The contact pin 105 is handled by a robot that engages the gripping projection 111 and can thereby apply a vertical movement and thus, for example, a pressing force to the contact pin 105 or bring the contact pin 105 into the soldering position. Fig. 7 shows a pre-assembled group comprising the assembly 2 and the pre-installed contact pins 105.

[0078] In a subsequent method step, the heat pipe 1 with its embossed area 103 is pushed onto the pre-installed contact pins 105, preferably in an automated manner, without applying force, and then, likewise preferably in an automated manner, is permanently clamped in place by applying a force acting in the axial direction of the contact pins 105. The forceless pushing on is indicated by the vertical arrow in Fig. 7. The embossed area 103 of the heat pipe 1 is preferably pressed onto the respective contact pin 105 by gripping and pulling in the pushed-through conical connecting area 110 together with the contact pin 105 and the arrangement 2, e.g., the printed circuit board.

[0079] A contact pin 105 in the form of a soldering pin is shown in Fig. 8. The soldering pin, like the press-fit pin according to Fig. 6, has an elongated conical connecting region 110 and a gripping projection 111. In this respect, reference can be made to the previous explanations. The soldering pin has an extension 119 at its end region facing the arrangement 2, which serves to establish a soldered connection between the soldering pin and an arrangement 2 (not shown in Fig. 8). With comparative reference to Fig. 7, the extension 119 can be soldered to a printed circuit board 201, engaging in a contact opening 206 or in a blind via (not shown). Alternatively, the extension can also be soldered to the top side of a printed circuit board or a substrate using SMD technology.

[0080] According to a further alternative embodiment of the invention, the contact pin 105 can also be designed as a leadframe pin. An example of such a configuration is shown in Fig. 9. The respective contact pin 105 is an integral component of a leadframe 208. The respective leadframe pin preferably has a truncated pyramid-shaped connecting region 110. As a result, a leadframe 208 with contact pins 105 integrated therein can be easily produced by means of a stamping process and subsequent bending of the contact pins into the desired orientation. For this configuration, the shape of the through-opening 106 of the embossed region 103 or 104 of the heat pipe 1 according to Figs. 4 and 5 should be adapted accordingly to the truncated pyramid shape of the elongated connecting region 110 of the contact pin 105.Otherwise, the leadframe pin corresponds to a press-fit pin or a solder pin of the previously described designs in terms of its features and its assembly with the embossed area of ​​a heat pipe 1. The leadframe pins shown in the drawings do not have gripping projections 111. However, gripping projections can also be used there if necessary.

[0081] In addition to the contact pins 105, the leadframe 208 also comprises electrical contacts 209 for an electrical connection of the component 205, e.g. the chip, which is arranged on the leadframe 208. The leadframe 208 can be bonded to a printed circuit board (not shown in Fig. 9) using the electrical connections using an SMD process, i.e. contact can be made with the latter. Heat generated at the component 205 can thus be transferred via the leadframe 208 and the contact pins 105 to one or more heat pipes 1. The orientation of the contact pins 105 can vary depending on the requirements or the installation situation and the application conditions. The contact pins 105 can, for example, be oriented parallel to the main surface of the leadframe 208 or protrude only at a right angle to one side of the leadframe 208. In the example shown in Fig.In the example shown in Figure 9, the contact pins 105 protrude at right angles to the top and bottom when viewed in the plane of the leadframe 208.

[0082] Fig. 10 shows an exemplary arrangement using the leadframe 208 with contact pins 105 in the form of leadframe pins from Fig. 9 in an exploded view. The leadframe is contacted with the circuit board on one side of the circuit board 201 via its electrical connections 209 using the SMD method, i.e., bonded to the circuit board, for example, in a soldering wave. Furthermore, the circuit board 201 has slit-like through-openings 210 through which the underside contact pins penetrate the circuit board 201, so that the contact pins 105 of the leadframe 208 can be pressed on the top and bottom with two heat pipes 1 each in the manner described, and thus, in this example, cooling of the component 205 can take place from both sides.

[0083] On the one hand, the invention enables improved heat transfer of a heat pipe 1 connected to an electrical or electronic arrangement 2 via contact pins 105. On the other hand, the invention can also achieve a higher degree of automated assembly compared to the prior art. For the thermal system design of power-lossy electronics, it practically represents a further degree of freedom alongside conventional cooling components and can also serve as a key component, e.g., for systems with components buried in printed circuit boards or next-generation power electronics. The present invention therefore represents a very special contribution to the relevant field of technology.

[0084] REFERENCE MARKS LIST

[0085] 1 heat pipe

[0086] 101 hollow bodies

[0087] 102 structural insert

[0088] 103 Embossing area

[0089] 104 embossing area

[0090] 105 Contact pin

[0091] 106 passage opening

[0092] 107 Press-in area

[0093] 108 inner wall area

[0094] 109 inner wall area

[0095] 110 Connection area

[0096] 111 Gripping projection

[0097] 112 Heat transfer medium

[0098] 113 Underside of the hollow body

[0099] 114 first area

[0100] 115 second area

[0101] 116 heat sinks

[0102] 117 Closure

[0103] 118 Recess

[0104] 119 Extension

[0105] 2 Arrangement

[0106] 201 circuit board

[0107] 202 Substrat

[0108] 203 Conductor track

[0109] 204 Conductor track

[0110] 205 component

[0111] 206 Contact opening

[0112] 207 Conductor coating

[0113] 208 Leadframe

[0114] 209 electrical contact 210 through opening a angle of inclination cone

Claims

PA TE N TA NCL RÜ CHE 1. Heat pipe (1) for a preferably electrical or electronic, preferably circuit board-shaped, arrangement (2) comprising an elongated, hermetically sealed hollow body (101), preferably in the form of a hermetically sealed tube, wherein a heat transport medium (112) is located in the interior of the hollow body (101), characterized by at least one embossed area (103, 104) narrowing the cross-section of the hollow body (101), wherein the embossed area (103, 104) forms an anchoring base for at least one contact pin (105), preferably for a group of contact pins (105).

2. Heat pipe (1) according to claim 1, characterized in that the embossed area (103, 104) for the at least one contact pin (105) has a through opening (106) which serves to fix the at least one contact pin (105) by means of a press fit.

3. Heat pipe (1) according to the preceding claims, characterized in that opposite inner wall regions (108, 109) touch in the embossed region (103, 104).

4. Heat pipe (1) according to the preceding claims, characterized in that in the interior of the hollow body (101), preferably on the inner wall thereof, there is a surface-enlarging, preferably fine-pored structure, preferably in the form of a structural insert (102).

5. Heat pipe (1) according to the preceding claims, characterized in that the hollow body (101) is deformed in the embossed area (103) on both sides towards the center with respect to the cross section of the hollow body (101).

6. Heat pipe (1) according to the preceding claims, characterized in that the hollow body (101) is flat on its underside facing the arrangement (2).

7. Heat pipe (1) according to claim 6, characterized in that the hollow body (101) of the heat pipe (1) adjoining the embossed area (104) does not project downwards beyond the underside of the embossed area (104).

8. Heat pipe (1) according to the preceding claims, characterized in that the embossed region (103, 104) divides the hollow body (101) into a first region (114) and a second region (115).

9. Heat pipe (1) according to claim 8, characterized in that the first and second regions (114, 115) are separated by a material connection, preferably by a welded connection, of the inner wall regions (108, 109) opposite the embossed region (103, 104).

10. Heat pipe (1) according to the preceding claims, characterized in that on an embossed area (103, 104) several contact pins (105) are arranged in a preferably straight row and / or with identical spacing from one another and / or in a preferably uniform surface pattern.

11. Heat pipe (1) according to the preceding claims, characterized in that the at least one contact pin (105) has a press-fit zone (107) as a press-fit pin or a soldering area for the mechanical and thermal connection of the heat pipe (1) to the arrangement (2) as a soldering pin or is arranged as a leadframe pin on a leadframe (208) or is an integral part of a leadframe (208).

12. Heat pipe (1) according to the preceding claims, characterized in that the at least one contact pin (105) has a long connection region (110) via which the embossed region (103, 104) can be plugged onto the contact pin (105).

13. Heat pipe (1) according to claim 12, characterized in that the elongated connecting region (110) of the at least one contact pin (105) projects upwards on the side of the embossed region (103, 104) opposite the arrangement (2).

14. Heat pipe (1) according to claim 12 or 13, characterized in that the long connecting region (110) of the at least one contact pin (105) is conical or truncated pyramid-shaped.

15. Heat pipe (1) according to the preceding claims, characterized in that the contact pin (105) comprises a gripping projection (111) for a preferably automated gripping tool.

16. Heat pipe (1) according to the preceding claims, characterized in that the at least one contact pin (105) protrudes from the embossed area (103, 104) on the side of the contact pin (105) opposite the arrangement (2) in the assembled state of the heat pipe (1).

17. Method for mounting a heat pipe according to the preceding claims on an electrical or electronic device (2) with the following method steps: Providing, preferably automated, an electrical or electronic arrangement (2), preferably a printed circuit board arrangement, press-fit mounting, preferably automated, of the at least one contact pin (105) in a blind hole or a through-opening (201) of the arrangement (2), or Solder pin assembly, preferably automated, of the at least one contact pin (105) in a blind hole or a through-opening (201) of the arrangement (2) or on the arrangement (2), Attaching, preferably automated, the embossed area (103, 104) of the heat pipe (1) to the pre-assembled contact pin (105) or vice versa, and Pressing the contact pin (105) with the embossed area (103, 104) of the heat pipe (1), preferably in an automated manner, by a force applied in the axial direction of the contact pin (105).

18. Method for mounting a heat pipe according to the preceding claims on an electrical or electronic device (2) with the following method steps: Providing, preferably automated, an electrical or electronic arrangement (2), wherein the electrical arrangement (2) comprises a leadframe (208) with at least one leadframe pin as a contact pin, Attaching, preferably automated, the embossing area (103, 104) of the heat pipe (1) to the leadframe pin or vice versa, and Pressing the contact pin (105) with the embossed area (103, 104) of the heat pipe (1), preferably in an automated manner, by a force applied in the axial direction of the contact pin (105).

19. The method according to claim 18, characterized in that the leadframe (208) is contacted to a printed circuit board (201) using the SMD method before the embossed area (103, 104) of the heat pipe (1) is plugged onto the leadframe pin or vice versa, preferably in an automated manner.

20. Method according to claims 17 to 19, characterized in that the insertion of the embossed area (103, 104) of the heat pipe (1) onto the connection area (110) of the pre-assembled contact pin (105) or vice versa is carried out with a clearance fit, 21. Method according to claims 17 to 20, characterized in that the contact pin (105) is pulled through in a direction opposite to the arrangement (2), whereby the contact pin (105) and the embossed area (103) of the heat pipe (1) are connected to one another in a press fit.

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