The invention relates to a device comprising a plurality of heat producing electronic components, said components being in contact with at least one heatsink arranged to discharge heat generated by said components, wherein said at least one heatsink comprises a metal body which is sandwiched between at least two of said components, said metal body having six faces, comprising two mutually opposite heat transfer faces to which the processing units are attached, two mutually opposite first side faces substantially perpendicular thereto, and two mutually opposite second side faces substantially perpendicular to the heat transfer faces and the first side faces. Such sandwiched processor unit are known, for instance the water cooled ZOTAC™ GeForce™ GTX 295 Infinity graphics card, wherein the metal body is provided with an internal conduit for cooling water and two external connectors for water hoses.

The current invention in particular, but not exclusively, relates to a computing device using submersion cooling wherein the flow of the cooling fluid is caused by convection. Submersion cooling of electronic components is a well known technology. Oil, or any other suitable dielectric fluid may be used as a cooling liquid. In order to efficiently cool the components the oil must flow along the components and along a cool heat exchanging surface for transferring the heat from the cooling liquid. Especially in datacentres an energy efficient system of cooling is required. The invention may also be applicable in non-submerged systems, for instance wherein the cooling fluid is air which is blown along the electronic components by a fan.

The invention aims at a compact, energy efficient, cost effective and/or reliable solution for an electronic device, suitable for use with convection cooling, in particular in a submerged electronic device.

To that end said metal body comprises a central through hole which extends between the two first side faces, to allow fluid to flow from the interior of the computer device into an opening of said through hole at one first side face and out of an opening of said through hole at the opposite first side face into the interior of the computer device.

Preferably said central through hole having a cross section sufficiently large so that during use said fluid flowing through said through hole accounts for at least the largest part of the cooling capacity for the metal body of said heat sink and thereby said components. Preferably said through hole has a substantially rectangular cross section, wherein the long edges of said rectangular cross section extend parallel to said heat transfer faces.

Preferably metal cooling fins extend from the walls of said through hole into the interior of said through hole, wherein said cooling fins extend parallel to the axis of the through hole, such that they do not obstruct the flow. Said cooling fins preferably divide said through hole in a plurality of substantially separated sub through holes. Preferably interruptions are formed in said cooling fins, in order to lower the Darcy friction of the flow. For production technical reasons, said metal body is preferably comprised of two separate halves, each halve comprising one of said heat transfer faces and one halve of the through flow opening, which are mounted together such that the halves of the through flow opening face each other.

Preferably a PCB is mounted on each of said components, wherein said metal body is sandwiched between at least two of said PCBs extending parallel to each other. In preferred embodiments said components are graphics processing units, central processing units, chips or electronic components.

The invention is of particular advantage if said computing device is a submerged computing device wherein said fluid is a liquid, such as oil, and if said computing device comprises a plurality of sandwiched heat sink and components, wherein the axes of said through holes of said heat sinks are aligned, such that fluid is allowed to flow through said holes along their common axis.

Preferably the axis of said through hole extends vertically. Said metal is preferably copper or aluminum. The thickness of said heat sink between said components is preferably smaller than 4 cm.

The invention furthermore relates to a sandwiched electronic unit comprising at least two heat producing components being in contact with a heatsink arranged to discharge heat generated by said components, wherein said heatsink comprises a metal body which is sandwiched between said at least two components, said metal body having six faces, comprising two mutually opposite heat transfer faces to which the components are attached, two mutually opposite first side faces substantially perpendicular thereto, and two mutually opposite second side faces substantially perpendicular to the heat transfer faces and the first side faces, wherein said metal body comprises a central through hole which extends between the two first side faces, to allow fluid to flow from the interior of a computer device into an opening of said through hole at one first side face and out of an opening of said through hole at the opposite first side face into the interior of said computer device.

The invention furthermore relates to a heatsink arranged to discharge heat generated by heat producing components, wherein said heatsink comprises a metal body, said metal body having six faces, comprising two mutually opposite heat transfer faces to which the components can be attached, two mutually opposite first side faces substantially perpendicular thereto, and two mutually opposite second side faces substantially perpendicular to the heat transfer faces and the first side faces, wherein said metal body comprises a central through hole which extends between the two first side faces, to allow fluid to flow from the interior of a computer device into an opening of said through hole at one first side face and out of an opening of said through hole at the opposite first side face into the interior of said computer device.

The invention will now be illustrated by means of a preferred embodiment, with reference to the drawings, wherein:

Figure 1 is a perspective view of a sandwiched processor unit with a heat sink in accordance with the invention; Figure 2 is a perspective view of the heat sink as used in the sandwiched processor unit of figure 1 ; Figure 3 is a perspective view of the lower half of the heat sink of figure 2; Figure 4 is a connecting part as used in the heat sink of figure 2;

Figure 5 is a frontal view of the heat sink of figure 2; and

Figure 6 is a perspective view of a frame for a computer device comprising a plurality of sandwiched processor units of figure 1.

According to figure 1 a sandwiched processor unit, such as a graphics processing unit (GPU) comprises two printed circuit boards (PCBs) 1, 2 extending parallel to each other, on each of which a processor (not shown) and other electronic components 3 and connectors 4 are mounted. A heat sink 5 extends between the boards 1 , 2, such that the processor of each board is in an optimised heat exchanging communication therewith. According to figures 2, 3, 4 and 5 the heatsink 5 is comprised of two identical halves 51, 52, which are mounted together by means of a spacer 53. The halves 51, 52 of the heatsink have a generally rectangular or square box shape. A solid rectangular plate shaped part 511, 521 of each of the halves 51, 52 is provided with mutually parallel cooling fins 512, 522 and mounting bushings 513, 523 extending the same distance from one side of said plate shaped part 511, 521 and being formed integral therewith. Preferably the halves 51, 52 are made of copper or aluminium.

Two arrays of interruptions 514, 524 are formed in said cooling fins 512, 522. During assembly of the heat sink, the cylindrical spacers 53 are inserted in matching cylindrical holes of each pair of opposite bushings 513. In the centre of each spacer 53 a widened ring shaped part 531 is provided which causes a small gap to exist between the assembled two halves 51, 52.

As can be seen in figure 5 the cooling fins 512, 522 and the plate shaped parts 511, 521 form substantially enclosed (sub) through holes 54 extending in parallel between the two opposite side faces of the assembled heat sink 5 (the through holes 54 may together also be considered as one central through hole having a profile formed by said cooling fins 512, 522 so as to form sub-holes 54). The interruptions 514, 524 form through holes 55 extending in parallel between the other two opposite side faces of the assembled heat sink 5.

As shown in figure 6, a frame 6 of a submerged computing device is provided with a plurality of sandwiched processing units 1, 2, 5 (in this example four). The frame 6 with the processing units is designed to be inserted vertically into a enclosed housing filled with a cooling liquid such as oil.

The heat sinks 5 are oriented such that the through holes 54 of the heat sinks 5 all extend vertically. It may be advantageous if the heat sinks are orientated such that the through holes 54 of the lower units 1, 2, 5 are aligned with the through hole 54 of the adjacent units 1, 2, 5 extending above, such that an unobstructed convection flow of the cooling liquid from the bottom to the top is possible.

The invention has thus been described by means of preferred embodiments. It is to be understood, however, that this disclosure is merely illustrative. Various details of the structure and function were presented, but changes made therein, to the full extent extended by the general meaning of the terms in which the appended claims are expressed, are understood to be within the principle of the present invention. The description and drawings shall be used to interpret the claims. The claims should not be interpreted as meaning that the extent of the protection sought is to be understood as that defined by the strict, literal meaning of the wording used in the claims, the description and drawings being employed only for the purpose of resolving an ambiguity found in the claims. For the purpose of determining the extent of protection sought by the claims, due account shall be taken of any element which is equivalent to an element specified therein. An element is to be considered equivalent to an element specified in the claims at least if said element performs substantially the same function in substantially the same way to yield substantially the same result as the element specified in the claims.