SK9726Y1 - Arrangement for cooling the electronic element on the PCB board of the removable module in the rack - Google Patents

Abstract

The removable module (1) includes a PCB board (2) with at least one electronic element (3) to which a metal cooler (4) is connected. The removable module (1) is adapted to be inserted into the body of the cabinet (5) by means of two parallel lines of contact, which keep the removable module (1) in position during insertion and also in the inserted position, while both lines of contact of the removable module (1) are formed by touching opposite sides of the metal cooler (4) with the cabinet body (5). Advantageously, the cooler (4) is wider than the width of the PCB board (2) and the edges of the cooler (4) protruding over the edges of the PCB board (2) are guided in opposite grooves (6) in the body of the cabinet (5). The body of the cabinet (5) can include two parallel plates and two side walls, while oppositely oriented grooves (6) and/or oppositely oriented tongues (7) are formed in the plates. Preferably, the removable module (1) has one heatsink (4), which is located in the central zone along the PCB board (2), preferably in the central third of the length of the PCB board (2).

Description

The field of technology

The technical solution refers to the arrangement of the removable module, which is inserted, for example, in a free-standing cabinet or in a cabinet intended for installation in a 19" or 10" rack, while the arrangement ensures cooling of at least one component located on the PCB board of the removable module through heat transfer to the body of the cabinet.

Current state of the art

Different methods of removing heat from electronic elements are known using flowing air, liquid cooling or using tubes with an evaporating substance. In passive cooling, a radiator is used, usually an aluminum radiator, which increases the area of heat removal to the surroundings. In rack cabinets, plug-in boards or plug-in modules are used, while the method of their cooling depends on the size of the cabinet and the projected heat generation on the corresponding electronic elements.

Publications US2015116940A1, US2008218980A1, US10356945B2 describe a socket module, the packaging of which is intended, among other things, to transfer heat to the guide rails of the cabinet. However, enclosing the module in the package worsens the ventilation of the electronic elements on the PCB board and also increases the overall dimensions of the module.

Electronic components according to publication US4118756A contact a thermally conductive plate which is formed on a PCB board such that the components are connected to the PCB board along the edges of the thermally conductive plate. This solution greatly limits the design of the PCB board and has not been implemented in practice. The US4366526A solution has a thermally conductive plate that supports the removable module in the cabinet drawer. A PCB board is connected to the heat-conducting plate. However, heat is generated in the electronic components on the opposite side of the PCB board, and the transfer of heat to the heat-conducting plate is mediated through the material of the PCB board.

There are also known systems that use the evaporation of substances with a suitable boiling point for cooling electronic components, such as according to the documents DE102013217615A1, US 4 793 405 A, US 4 019 098 A, but such systems are complex and lead to relatively large cabinet dimensions.

Publication US 5,946,191 describes a plug-in module having a stop adapted to conduct heat from the surface of the processor to the cooling system of the case. The electronic module according to US 5,283,715 uses a composite carrier to transfer heat from the PCB board to the cooler located next to it, which makes it possible to substantially increase the heat exchange surface, but increases the space requirements. Publication US 2009284924A clarifies the cooling of the side walls of the cabinet by means of a cooling pipe, wherein the cabinet is equipped with partitions to improve the transfer of heat to the side walls. All these technical solutions are complicated, space-consuming and provide only a small improvement in the cooling effect.

These shortcomings are partially solved by the arrangement according to publication US2015208551A1, which transfers heat from the surface of the processors using heat transfer tubes to the side wall of the case, while when inserting the removable module into the case, plugs are inserted into the grooves on the side in the body of the case, which are pressed into contact with the surface by a flat spring depressions. A long line of heat transfer pipes brings a risk of mechanical damage, and the system requires a special line of the removable module and especially the line of the plugs. Thermal plugs are also used by the system according to US 2012103571A1, which has plugs located on the back wall of the removable module.

With relatively small dimensions of plug-in modules, such as memory modules, existing cooling methods lead to complicated constructions with large dimensions. It is desirable to present a simple structural arrangement with good heat transfer from the removable module to the case body, while ensuring small, compact dimensions and simple production technology.

The essence of the technical solution

The aforementioned shortcomings are substantially eliminated by the arrangement for cooling the electronic element on the PCB board of the removable module in the cabinet, where the removable module includes a PCB board with at least one electronic element to which a metal cooler is connected, and where the removable module is adapted to be inserted into the body of the cabinet so , that drawer folders are created in the body of the cabinet and the removable module is guided by two parallel lines of contact when it is inserted into the corresponding folder, which keep the removable module in position during insertion and also in the inserted position, according to this technical solution, the essence of which is that both lines of contact are formed by the contact of the opposite sides of the metal cooler with the case body or the opposite sides of several metal coolers with the case body.

An important feature of the presented technical solution is the direct contact of the metal cooler with the cabinet body, while the metal cooler forms the mechanical guide of the removable module in the cabinet. It is advantageous if the only mechanical contact of the removable module with the body of the cabinet is exclusively through the contact of the cooler with the body of the cabinet. The state of the art describes solutions where the cooler of the removable module is connected to the cooling device in the cabinet using a heat-conducting element, but this function was not connected to the mechanical guidance of the removable module in the corresponding folder of the cabinet body. The presented technical solution provides a simple heat transfer from the cooler of the electronic element so that the cooler itself carries and positions the removable module in the case, and thus ensures a good heat transfer without the edges of the PCB board being guided in the grooves. This arrangement not only leads to a simple construction without duplication of guiding elements, but also improves the contact of the cooler with the body of the case, since the entire weight of the removable module is transferred through the cooler, or through several coolers on one removable module.

It will be advantageous if the heat sink is wider than the width of the PCB board and the edges of the heat sink protruding from the edges of the PCB board are inserted in the opposite grooves of the folder. These grooves in the body of the case and the edges of the heatsink protruding from the floor plan of the PCB form the drawer sliding mechanism. It is the solution with protruding edges of the cooler, preferably in a symmetrical position, that is technologically simple. Folders for the appropriate number of removable modules are created in the body of the cabinet, and each folder is equipped with two parallel, oppositely located grooves into which the protruding edges of the cooler fit.

The term width in this document preferably refers to the dimension that is transversely oriented to the direction of insertion and extraction of the removable module in the cabinet.

In another embodiment, the tongue/groove socket line for guiding the cooler in the body of the cabinet can be created in the opposite way, in such a way that parallel grooves are created in the opposite edges of the cooler, into which the tongue protruding from the pocket of the body of the cabinet fits.

If the removable module has one heatsink, it will be convenient if it is located in the central zone of the PCB board, that is, approximately in the middle third or in the middle quarter of the length of the PCB board, which will achieve the balance of the storage and the easy process of inserting and removing the removable module. An arrangement is also possible where the electronic element is placed less symmetrically and the cooler with a larger footprint than the footprint of the respective electronic element is oriented in such a way as to achieve greater symmetry of the center of the cooler to the entire footprint of the removable module. At the same time, the basic technical idea of the presented technical solution is also observed when the removable module has several coolers and only one or only some of them are used to create a drawer mechanism. For example, a component with significantly less heat development can be equipped with a smaller cooler that does not extend beyond the side edges of the PCB board, and the cooler on the main electronic element will be designed to create a plug-in mechanism, i.e. it will be equipped with a tongue and/or groove to be inserted into the body of the cabinet with the appropriate shaped guide (groove and/or tongue).

If several heatsinks are adapted to be guided in the body of the cabinet on one removable module, it is advantageous if they are all guided in one groove, but in general and with larger thicknesses of the coolers, multiple grooves can also be created.

If the tongues on the sides of the cooler are created by milling, their exact position within the side wall can be chosen so that the joint between the tongues passes through the center of gravity plane or directly through the center of gravity of the entire removable module. This achieves the static balance of the removable module and makes it easier to extend and retract it without crossing and jamming problems. The exact determination of the position of the tongue relative to the center of gravity of the entire removable module (including the weight of the cooler itself) can be optimized even with a different design of the tongue/groove contact line.

The presented technical solution is applicable to any removable modules with at least one electronic element, such as a single board computer (SBC), a system on a chip (SoC), a processor (CPU/GPU) or a memory module. The electronic element is soldered on the PCB board or inserted in a socket, and an aluminum heatsink is attached to the upper surface. With SBC, the length of the module and thus the length of the PCB board will usually exceed three times the width of the SBC, or width of the PCB board. To connect the cooler to the upper surface of the electronic element, known methods of connection are used, for example, mechanical attachment using screws, clips and the like, preferably with the use of heat-conducting tape or heat-conducting sealant.

A removable module will usually have a PCB board mounted on one side, but the PCB board can be mounted on both sides, and it is preferred that the electronic elements with the heatsink that forms the wiring of the removable module are only on one side of the PCB board.

The floor plan shape of the cooler will mainly be quadrangular or rectangular, but it can be essentially arbitrary, while it will have opposite, parallel sides intended for contact with the body of the cabinet.

In one of the advantageous versions, the cabinet body is made of aluminum sheets and/or profiles, which are equipped with grooves for guiding coolers. The cabinet can be composed of two plates, the mutual distance of which is firmly determined by two side walls. The folders in the body of the cabinet are defined by a pair of grooves in the plate. The grooves are parallel and have a profile that loosely corresponds to the thickness of the protrusions on the sides of the cooler. The plates may have holes to improve air flow to individual folders. When spreading heat from electronic elements on removable modules, the contact of the edges of the cooler with the partitions is important, from where the heat subsequently spreads to the entire body of the cabinet. At the same time, the edges of the PCB board are located freely in the space of the folder without touching the body of the cabinet. The connection connectors of the module are in contact.

In order to simplify the insertion of the removable module, the clearance in the slot can be increased to a dimension exceeding 2 mm. In order to subsequently ensure the end position of the removable module, the clearance can be significantly smaller in the end position. This can be achieved by variable groove width and/or variable pen thickness. In another embodiment, the end position can be ensured by means of a locking element, preferably by means of a flat spring, which is attached to the end of the groove and presses the tongue against the opposite surface of the groove.

At the beginning of the track, the grooves may have a short slanted extension to facilitate the guide of the pen into the groove. The beginning of the pen can also be slanted.

An important advantage of the presented technical solution is a simple construction with excellent heat dissipation directly from the cooler of the electronic element to the cabinet body, which has a relatively large heat exchange surface with the surroundings. Inserting the removable module into the cabinet is easy, it does not require separate connection of heat-conducting paths. The advantage is also the relief of the PCB board from mechanical stress and vibrations during the insertion and extraction of the removable module, the relatively massive and at the same time metal part of the removable module, i.e. the cooler, is used to transfer forces.

Overview of images on drawings

The technical solution is explained in more detail with the help of figures 1 to 9. The depicted scale of individual elements on the PCB board, the shape and number of folders, the relative dimensions of the grooves to the total size of the cabinet body are only examples and should not be interpreted as signs limiting the scope of protection.

Figure 1 shows a partial cross-section of a removable module in place of a single-board computer with a heatsink in an arrangement where the width of the heatsink exceeds the width of the PCB board. Subsequently, in Figure 2, the example from Figure 1 is shown in a view from the side of the connection connector.

Figure 3 is a plan view of a removable module with one single board computer, where the removable module is first shown in the selected position in the upper part of the figure and then in the lower part of the figure as inserted in the working position. The arrow indicates the direction of insertion of the removable module into the cabinet.

Figure 4 shows a view of the cabinet plate with holes to support cooling, while only one removable module is inserted in the cabinet for clarity. The position of the cooling holes is chosen in such a way that a transverse channel for air conduction is created next to the upper surface of the cooler.

Figure 5 shows an embodiment where grooves are formed in the side walls of the cooler, into which a copper tongue pressed into the grooves of the body of the cabinet fits.

Figure 6 shows a schematic representation where the groove in the body of the case has a width corresponding to the thickness of the cooler.

Figure 7 shows the body of the cabinet assembled from several identical aluminum profiles, which, during extrusion, have a directly formed groove for guiding the cooler.

Figure 8 shows the location of the flat spring to catch the heatsink in the end position of the removable module when viewed perpendicular to the slot. At the top is a view perpendicular to the surface of the housing body with a slot, and at the bottom of the image is a partial sectional view in the A-A plane that passes through the flat spring at the point of its contact with the spring.

Figure 9 shows the body of the cabinet assembled from several identical aluminum profiles, which during extrusion have a groove directly created to guide the entire thickness of the cooler.

Implementation examples

Example 1

In this example, according to Figures 1 and 4, the cabinet 5 is made of two aluminum plates and two aluminum side walls, which determine the mutual distance between the plates.

The removable module 1 has a PCB board 2, the width of which is smaller than the distance between the inner surfaces of the plates. On the removable module 1 is an electronic element 3, in this example a Raspberry Pi CM4 single-board computer. On the upper surface of the electronic element 3, a cooler 4 made of an aluminum profile is attached.

Cooler 4 has a rectangular floor plan and the upper side is equipped with ribs. The width of the cooler 4 is greater than the width of the PCB board 2, on both sides of the cooler 4, which protrude from the floor plan of the PCB board 2, a protrusion is created, in this example in the form of a milled tongue 7. The thickness of the tongue 7 with clearance corresponds to the width of the groove 6 so that smooth guidance of the pen 7 in the groove 6 was ensured without crossing and without the need for excessive effort when inserting and withdrawing the removable module 1 from the cabinet 5. In this example, a recess is milled in the floor plan of the cooler 4, which allows the connection of the antenna connector on a single-board computer.

Parallel grooves 6 are formed in the plates. In this example, the grooves 6 are formed from the edge of the plate to a position in which the end of the groove 6 forms a stop for the end position of the removable module 1. At the beginning, the grooves 6 have a short slant, which makes it easier to guide the pen 7 into grooves 6. The bevel is created in both directions, that is, the groove 6 has a greater width at the beginning of its path and also has a greater depth.

As shown in Figure 3, the removable module 1 is inserted into the cabinet 5 so that it first has no wiring in the cabinet 5. After inserting the removable module 1 to a depth corresponding to the position of the edge of the heatsink 4, both tongues 7 are inserted into the opposite grooves 6 and the entire removable module 1 team gains mechanical leadership. After inserting the removable module 1 into the final working position, the entire removable module 1 is guided by the edges of the cooler 4, and these points of contact create a heat transfer bridge for heat removal to the cabinet body 5.

The aluminum plates forming the base of the cabinet 5 have a series of longitudinally guided ventilation holes, which are located outside the grooves 6. In this example, for each removable module 1, a pair of ventilation holes is determined on each aluminum plate, and these holes are located opposite each other, creating a channel for transverse flow of air past the PCB board 2 and especially past the upper surface of the cooler 4.

Example 2

In this example, according to Figure 5, the contact between the tongue 7 and the groove 6 is created in the opposite way as in example 1. The tongue 7 is on the side of the case 5 and the groove 6 is milled into the opposite sides of the cooler 4. In this example, the tongue 7 is made of a copper strip, which is pressed into the cabinet body 5.

Example 3

In this example, according to Figure 6, the groove 6 in the body of the case 5 has a larger width, which corresponds with the clearance to the thickness of the cooler 4. The side walls of the cooler 4 protruding from the floor plan of the PCB board 2 thus directly form the tongue 7.

Example 4

The cabinet 5 according to Figure 7 is made of several repeating identical aluminum extruded profiles, which are joined into an assembly according to the required number of folders. The profile has a formed groove 6 into which the tongue 7 formed on the edges of the cooler 4 fits.

Example 5

To reduce the play of the guide of the pen 7 in the groove 6 in the place of the final working position of the removable module 1, the groove 6 can have a variable width or the groove 6 can be supplemented with a flat spring, as shown in Figure 8. The flat spring presses the pen 7 against the surface of the groove 6 and at the same time secures the end position of removable module 1.

Example 6

The cabinet 5 according to Figure 9 is made of several repeating identical aluminum extruded profiles, which are joined into an assembly according to the required number of folders. The profile has a groove 6, into which the entire thickness of the cooler 4 fits.

Industrial applicability

The industrial applicability is obvious. According to this technical solution, it is possible to industrially and repeatedly manufacture and use an arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet. The solution can be used especially when setting up a computer cluster with the possibility of scaling the number of plug-in removable modules according to the customer's needs.

List of relation marks and abbreviations

- removable module

- PCB board

- electronic element

- cooler

- wardrobe

- groove

- pen

PCB - printed circuit board

SBC- single board computer

SoC - system on a chip CPU/GPU - processor

Claims (17)

CLAIMS FOR PROTECTION 1. An arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet, where the removable module (1) includes a PCB board (2) with at least one electronic element (3) to which a metal heatsink (4) is connected, and where the removable module (1) is adapted to be inserted into the body of the cabinet (5) so that the removable module (1) is guided by two parallel lines of contact during insertion, which keep the removable module (1) in position during insertion and also in the inserted position, characterized by , that both lines of contact of the removable module (1) are formed by the contact of the opposite sides of the metal cooler (4) or several metal coolers (4) with the case body (5). 2. An arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to claim 1, characterized in that the cooler (4) is wider than the width of the PCB board (2) and the edges of the cooler (4) protrude beyond the edges of the PCB board ( 2) are guided in opposite grooves (6) in the cabinet body (5). 3. Arrangement for cooling the electronic element on the PCB board of the removable module in the cabinet according to claims 1 or 2, characterized in that the removable module (1) has one cooler (4) located in the central zone along the PCB board (2), preferably in the central third of the length of the PCB board (2). 4. Arrangement for cooling the electronic element on the PCB board of the removable module in the cabinet according to any one of claims 1 to 3, characterized in that on both sides of the cooler (4) there is a pen (7) whose thickness corresponds to the width of the groove (6) in the cabinet body (5). 5. An arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 3, characterized in that the side edges of the cooler (4) are equipped with grooves (6) into which the tongue (7) fits from the side of the body cabinets (5). 6. Arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 5, characterized in that the body of the cabinet (5) includes two parallel plates and two side walls, while the plates are formed oppositely oriented grooves (6) and/or oppositely oriented tongues (7). 7. Arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 6, characterized in that the cooler (4) has ribs on the surface opposite to the contact surface through which it is in contact with the surface of the electronic element ( 3), and the tongues (7) or grooves (6) on the sides of the cooler (4) are formed by milling or extrusion. 8. An arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 7, characterized in that the cooler (4) has a length greater than the width. 9. An arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 8, characterized in that the connector between the pins (7) passes through the center of gravity of the removable module (1) or is located at a distance of up to 5 mm from the center of gravity removable module (1). 10. An arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 3, 6 to 9, characterized in that the side edges of the cooler (4) form a tongue (7) for insertion into the groove (6) in cabinet body (5). 11. Arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to claim 10, characterized in that the width of the cooler (4) is greater than the width of the PCB board (2) and/or the width of the PCB board (2) is less than the distance between the inner surfaces of the cabinet body (5) in the adjacent area of the PCB board (2). 12. Arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 5, 7 to 11, characterized in that the body of the cabinet (5) is made of an extruded aluminum profile, preferably made of by repeatedly connecting several aluminum extruded profiles. 13. Arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 12, characterized in that the width of the groove (6) and/or the thickness of the tongue (7) is different in the position corresponding to the insertion of the removable module ( 1) and in the end position. 14. An arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 13, characterized in that in the body of the cabinet (5) there is at least one locking element for each removable module (1) on ensuring the final position of the removable module (1) in the cabinet body (5). 15. An arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to any one of claims 1 to 14, characterized in that the body of the cabinet (5) has openings for the flow of cooling air, preferably having a group of two opposite openings for each removable module (1). 16. Arrangement for cooling the electronic element on the PCB board of the removable module in the cabinet according to claim 15, characterized in that the holes on the opposite plates of the cabinet body (5) are located in the zone of the location of the cooler (4) in the end position of the removable module (1). 17. Arrangement for cooling an electronic element on a PCB board of a removable module in a cabinet according to 5 of any one of claims 1 to 16, characterized in that the electronic element (3) is a single-board computer and/or a system on a chip, and/or a processor, and/ or memory module.