Patent Publication Number: US-2018040536-A1

Title: Single base multi-floating surface cooling solution

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The application claims the benefit of the earlier filing date of co-pending U.S. Provisional Patent Application No. 62/289,222, filed Jan. 30, 2016 and incorporated herein by reference. 
    
    
     BACKGROUND 
     The disclosure generally relates to the field of integrated circuit (IC) devices and, more particularly, to techniques and configurations for heat removal from multi-chip packages or a portion, including an entire portion, of a motherboard using a heat exchanger (e.g., a heat sink) and thermal conduits, such as a heat pipe or thermally conductive rod for multi-surface components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a top side perspective view of an embodiment of a multi-chip central processing unit (CPU) package. 
         FIG. 2  shows a side view of an assembly including the multi-chip package of  FIG. 1  having a heat sink thereon. 
         FIG. 3  shows a cross-section through line  3 - 3 ′ of  FIG. 2 . 
         FIG. 4  shows a bottom side perspective view of the heat sink of  FIG. 2  and a portion of the heat sink through line A-A′. 
         FIG. 5  shows a side perspective view of the assembly of  FIG. 2  and a portion of the assembly through line B-B′. 
         FIG. 6  shows a top side perspective view of another embodiment of a multi-chip package. 
         FIG. 7  shows a bottom perspective view of an embodiment of a heat sink operable for connection to the multi-chip package of  FIG. 6 . 
         FIG. 8  shows a cross-section of the assembly of the package of  FIG. 6  and the heat sink of  FIG. 7  through line  8 - 8 ′ of  FIG. 7 . 
         FIG. 9  shows a bottom perspective view of a heat sink including a floating heat transfer surface with multiple heat pipes connected to the heat transfer surface. 
         FIG. 10  shows a top perspective view of an assembly including a multi-chip package and voltage regulators. 
         FIG. 11  shows a bottom perspective view of a heat sink operable for connection to the assembly of  FIG. 10 . 
         FIG. 12  shows a side perspective of an assembly of the assembly of  FIG. 10  and the heat sink of  FIG. 11  and a cross-section portion through line D-D′. 
         FIG. 13  illustrates an embodiment of a computing device. 
     
    
    
     DETAILED DESCRIPTION 
     IC technology companies may be developing more integrated multi-chip products consisting of, for example, processor, memory and companion chips. Packaging can consist of a single IHS (Integrated Heat Spreader) over all the components or individual IHSs for each component.  FIG. 1  shows a top side perspective view of a generic multi-chip central processing unit (CPU) package. Package  100  includes die  110  disposed on processor substrate  105 . Overlying die  110  is IHS  120  with a thermal interface material (TIM) there between (TIM 1 ). In this exemplary embodiment, package  100  also includes secondary devices of, for example, memory chip  130 A, memory chip  130 B, memory chip  140 A, memory chip  140 B, as well as companion chip  150 A and companion chip  150 B that are, for example, each a processor. It is appreciated that the secondary devices as memory chips and companion chips are one example. In another embodiment, other types of devices can be present in the package. Each of the primary device (die  110 ) and the secondary devices (memory chips  130 A/B,  140 A/B, and companion chips  150 A/B) are connected in a planar array to substrate  105 . In one embodiment, a thickness (z-dimension) of one or more of the secondary devices is different than a thickness (z-dimension) of die  110 . In one embodiment, one or more of the secondary devices has a z-dimension thickness that is less than a thickness of die  110 . In another embodiment, a z-dimension thickness of one or more secondary devices is different from die  110  and one or more other secondary devices. 
     In one embodiment, overlying each secondary device is an IHS with a respective TIM 1  therebetween. In this embodiment, one IHS overlies two secondary devices.  FIG. 1  shows IHS  135  on memory chip  130 A and on memory chip  130 B; IHS  145  on memory chip  140 A and on memory chip  140 B; and IHS  155  on companion chip  150 A and on companion chip  150 B. In another embodiment, adjacent secondary devices may have an individual IHS (not shared). In one embodiment, TIM 1  is consistently thin or effectively minimal between each IHS and its respective device to improve the thermal performance between each heat generating component and a cooling solution and thus minimize the temperature of each component. In one embodiment, a suitable TIM 1  is a polymer TIM with a standard thickness. In a further embodiment, an IHS may not be present on or over die  110  or one or more of the secondary devices. 
     In some solutions, the emphasis is on the thermal improvements which can be achieved from a junction of a component or device to the cooling solution base such as the base of an air-cooled heat sink.  FIG. 2  shows a side view of an assembly including the multi-chip package of  FIG. 1 . Referring to  FIG. 2 , assembly  101  includes a cooling solution that, in this embodiment, is a passive heat exchanger that is a heat sink including heat sink base  170  and fins  180 . The heat sink includes an xy area dimension that, in one embodiment, is similar to multi-chip package  100  and is disposed over an area portion of multi-chip package  100  including heat generating devices (e.g., an area including the primary device and secondary devices).  FIG. 2  shows the heat sink over or on CPU die  110  and IHS  120  with heat sink base  170  justified to IHS  120 . Heat sink base  170  is justified to IHS  120  in the sense that it is in physical contact with the IHS or in contact with a TIM 2  material disposed on a surface of IHS  120  to a minimum effective thickness for such material. 
     In one embodiment, the heat sink includes one single or indivisible heat sink base (base  170 ) and one single or indivisible fin structure (fins  180 ). In one embodiment where one or more secondary devices and corresponding IHS are at a different z-height then primary device (die  110 ) and its IHS (IHS  120 ), portions of base  170  may include cavities for heat sink base portions and associated springs to compensate for a difference in z-height.  FIG. 2  shows the heat sink including heat sink base  170  and fins  180  also includes a cavity or cavities over areas corresponding to ones of the secondary devices of multi-chip package  100 , notably, in this example, companion chips  150 A and  150 B. Disposed within such cavities are heat sink base portions that are deflectable portions (deflectable in a z-direction).  FIG. 2  shows second heat sink base portion  172  disposed over or on IHS  155  on companion chip  150 A and companion chip  150 B. In one embodiment, cavity  171  does not extend through heat sink base  170 . In another embodiment, cavities may extend through the base in the form of openings. 
     The introduction of a cooling solution on multi-chip package may include coupling of self-adjusting heat sink surfaces to multi-surface height components to minimize both TIM 1  (between the die and IHS) and TIM 2  (between the IHS and cooling solution base) and may result in significant increased thermal performance and opportunities.  FIG. 3  shows a cross-section through line  3 - 3 ′ of  FIG. 2 .  FIG. 3  illustrates TIM 1  between each of chip  150 A and chip  150 B and IHS  155 .  FIG. 3  also illustrates heat sink base  170  and fins  180  on or over IHS  155 . In this embodiment, heat sink base  170  includes cavity  171  over an area corresponding to IHS  155 . Disposed within cavity  171  of heat sink base  170  is heat sink base portion  172 . Heat sink base portion  172  is biased away from heat sink base  170  by spring  173  in the cavity (between heat sink base  170  and heat sink base portion  172 ). 
     In the embodiment illustrated in  FIGS. 1-3 , primary die  110  and IHS  120  have a greater z-height than a z-height of secondary device  150 A and secondary device  150 B with their corresponding IHS (IHS  155 ). Because heat sink base  170  is justified to IHS  120 , there is a gap defined by a thickness, t, between a surface of heat sink base  170  and a top surface of IHS  155 . In order to minimize a TIM 2  thickness between the heat sink and IHS  155 , heat sink base portion  172 , because it floats (i.e., can move in a z-direction) in cavity  171  and is biased away from heat sink base  170  by spring  173 , heat sink portion  172  extends a distance below (as viewed) a base of heat sink base  170  equivalent to at least a portion of the gap defined by thickness, t. In one embodiment, heat sink base portion  172  extends a distance below a base of heat sink base  170  to minimize a TIM 2  thickness.  FIG. 3  shows TIM 2  between heat sink base portion  172  and IHS  155 . It is appreciated that a secondary device and associated IHS, if present on the secondary device, in certain embodiments may have a z-height greater than a z-height of primary die  110  and IHS  120 . In that instance, a heat sink base portion will be recessed in a cavity of the heat sink base so that surface operable to contact the secondary device or IHS (if present), is within the cavity. In another embodiment, the heat sink base may be justified to the secondary device and its associated IHS (if present) and the deflectable or floating heat sink base portion may be positioned in an area corresponding to the primary device (e.g., die  110 ). 
       FIG. 4  shows a bottom perspective view of the heat sink of  FIG. 2  including heat sink base  170  and heat sink fins  180 . In a lower portion of the figure, a portion of the heat sink is shown bisected through line A-A′.  FIG. 4  shows heat sink base  170  and fins  180  and illustrates heat sink base portion  172  positioned in cavity  171  in an area of heat sink base  170  corresponding to where the heat sink (heat sink base  170  and fins  180 ) is located over companion chip  150 A and companion chip  150 B, respectively. In one embodiment where other secondary devices (e.g., memory chip  130 A,  130 B,  140 A,  140 B) and their corresponding IHS are at a different z height than a z height of processor  110  and IHS  120 , additional heat sink base portions may be positioned in cavities in heat sink base  170  in areas corresponding to the secondary device.  FIG. 4  shows spring  173  disposed in cavity  171  between heat sink base  170  and heat sink base portion  172  with spring  173  biasing the heat sink base portion away from heat sink base  170 . Internal spring  173  provides a force on the floating heat transfer surface that is adequate to control a thin TIM 2  bond line (or TIM 1  if IHS is not present). The spring reaction force is transferred back into heat sink base  170 . 
       FIG. 4  shows heat sink base  170  has a first side on which fins  180  are disposed. In this embodiment, on an opposite second side, heat sink base  170  includes cavity  171  to contain heat sink base portion  172  over an area corresponding to secondary devices on substrate  105  (see  FIGS. 1-3 ). Heat sink portion  170  also includes channels  1725  (two channels) formed therein to contain one or more thermally conductive conduits, such as one or more heat pipes or thermally conductive rods (e.g., a metal rod (e.g., a copper rod) or composite rod). For purposes of this discussion, a thermally conductive conduit of a heat pipe is described. It is appreciated that other thermally conductive conduits could be substituted for a heat pipe. Referring to  FIG. 4 , in one embodiment, one or more heat pipes are positioned or nested in channels  1725  of heat sink base  170  heat pipes are positioned completely in respective channels so that a surface of heat sink base  170  is defined by a surface of the base and not a heat pipe protruding from a channel. In one embodiment,  FIG. 4  shows heat pipe  1750 A and heat pipe  1750 B positioned in respective channels  1725  of heat sink base  170 . Heat pipe  1750 A is positioned in an area corresponding to an area of package  100  including die  110  and ones of the secondary devices (e.g., memory chip  130 A, memory chip  130 B, memory chip  140 A, memory chip  140 B).  FIG. 4  shows heat pipe  1750 B positioned in a channel in an area corresponding to an area of package  100  including companion chips  150 A and  150 B and secondary chips  140 A/ 140 B and die  110 . Channel  1725  in which heat pipe  1750 B is disposed extends to cavity  171 . Heat pipe  1750 B is connected to heat sink base portion  172  (so that the heat pipe is between heat sink base portion  172  and heat sink base  170 ) and therefore floats to the extent heat sink base portion  172  moves up or down. In one embodiment, there are three parts to heat pipe  1750 B. One section of the heat pipe (e.g., a first end) is directly positioned in a channel and attached (e.g., soldered into heat sink base  170 ); another section (e.g., a middle section) is positioned in channel  1725  but not attached to heat sink base  170 ; and a third section is connected to heat sink base portion  172  as the floating heat transfer surface. This approach secures the position of the heat transfer surface in an xy plane. A z-dimension of heat sink base portion  172  is determined by internal spring  173  when the heat sink is installed on the package assembly as shown in  FIG. 5 .  FIG. 5  shows a side perspective view of the assembly of  FIG. 2  with a lower portion showing a cross-section through line B-B′. As shown in  FIG. 5 , heat pipe  1750 B is at a first z-height in an area of heat sink base  170  approximately corresponding to an area of die  110  of package  100  and at a second z-height (lower) in an area where the pipe is connected to heat sink base portion  172 . 
     Heat is removed from the companion chips by conduction through the TIM 2  and floating heat transfer surface (including heat sink base portion  172 ) and into heat pipe  1750 B. Heat pipe  1750 B then transfers the heat into the single base heat sink (into heat sink base  170  and fins  180 ). As described above, in one embodiment, heat pipe  1750 B has a section that is not directly attached to heat sink base  170  and provides the float required for the heat transfer surface. This section is malleable and allows for the vertical motion of the floating heat transfer surface. The travel distance of the floating surface is extremely minimal from a mechanical perspective and will not impact the reliability of the heat pipe. A representative travel distance is on the order of 0.125 millimeter (mm) to 0.500 mm. 
     In one embodiment, each of heat pipes  1750 A and  1750 B contains a fluid. A material for each of heat pipes  1750 A- 1750 B is selected for a working temperature range of interest and fluid compatibility. Examples of material include copper with water as the fluid and aluminum with ammonia as the fluid. Other materials may be selected for other fluids (e.g., helium, mercury sodium). Each of heat pipes  1750 A- 1750 B, in one embodiment, also contains a wicking material therein. A representative diameter range for heat pipes  1750 A- 1750 B is 0.5 millimeters (mm) to 20 mm. A representative example diameter is on the order of 6 mm. A cross-sectional shape of a heat pipe may be circular, oval, rectangular, or other shape. 
       FIGS. 6-8  show another embodiment of an assembly including a multi-chip package and a heat sink.  FIG. 6  shows a top side perspective view of another embodiment of a multi-chip package. Package  200  includes die  210  disposed on processor substrate  205 . Overlying die  210  is IHS  220  with TIM 1  between the device and the IHS. In this embodiment, package  200  also includes companion chip  250  as a secondary device having IHS  255  disposed thereon with a TIM 1  between the device and the IHS. In this embodiment, companion chip  250  and its associated IHS  255  have a different z-height or z-dimension thickness than a z-dimension thickness of die  210  and its associated IHS  220 . 
       FIG. 7  shows a bottom perspective view of a heat sink that, in one embodiment, includes an xy area dimension that, in one embodiment, is similar to package  200 . The heat sink, in this embodiment, includes one single or individual heat sink base (base  270 ) and one single or indivisible fin structure (fins  280 ).  FIG. 8  shows a cross-section of an assembly including package  200  with the heat sink of  FIG. 7  thereon. The cross-section of the heat sink is taken through line  8 - 8 ′ of  FIG. 7 . 
     In one embodiment, a heat sink (heat sink base  270  and fins  280 ) is justified to IHS  220  on die  210  of multi-chip package  200 . As noted above, companion chip  250  and its associated IHS has a different z-height than a z-height of die  210  and IHS  220 . As illustrated, the z-height of companion chip  250  and IHS  255  is less than a z-height of die  210  and IHS  220 . Accordingly, heat sink base  270  includes cavity  271  disposed through a backside of the heat sink base (a side opposite fins  280 ) and heat sink base portion  272  disposed in cavity  271  and biased from heat sink base by spring  273  (see  FIG. 8 ).  FIG. 7  also shows channels  2725  (two channels) formed in heat sink base  270 . Disposed within respective channels  2725  are heat pipe  2750 A and heat pipe  2750 B. In this example, heat pipe  2750 A is positioned in channel  2725  in an area corresponding to an area of package  200  including die  210 . Heat pipe  2750 B is positioned in an area corresponding to an area of package  200  including companion chip  250 . Heat pipe  2750 B is connected to heat sink base portion  272  and therefore floats to the extent the heat sink base portion moves in a z-direction (e.g. up or down). In one embodiment, heat pipe  2750 B may be connected to heat sink base  270  at a first end in an area corresponding to an area of die  210 ; have a middle portion that is positioned in channel  2725  but not connected to heat sink base  270 ; and a third section connected to heat sink base portion  272  as the floating heat transfer surface. 
     In one embodiment, heat sink base portion  272  (the floating heat transfer surface) can be selected for the companion component size and the heat removal required based on its thermal design power (TDP). For companion chips with low TDP (e.g., in the 20 watt to 30 watt range), a single heat pipe (heat pipe  2750 B) can be utilized with a compressive load based on IHS surface area and a requirement of an individual die. For components with higher TDP, a floating heat transfer surface can be attached to multiple heat pipes so as not to exceed a maximum heat capability of each heat pipe.  FIG. 9  shows a bottom perspective view of a heat sink including heat sink base  370  and fins  380 . In this embodiment, heat sink base  370  includes channels  3725  (two channels) with heat pipes  3750 A and  3750 B respectively positioned therein. In this embodiment, heat sink base includes heat sink base portion  372  that can act as a floating heat transfer surface as described above. As illustrated in  FIG. 9 , in this embodiment, each of heat pipe  3750 A and heat pipe  3750 B is connected to heat sink base portion  372 . 
       FIG. 10  shows a top perspective view of another embodiment of a multi-chip package assembly. In this embodiment, assembly  400  includes substrate  402  on a surface of which is connected multi-chip package including substrate  405 , die  410  and companion chip  450 . Overlying die  410  is IHS  420  with, for example, a TIM 1  therebetween and overlying companion chip  450  is IHS  455  with, for example, a TIM 1  therebetween. Assembly also includes one or more voltage regulator components such as inductors  430  disposed on substrate  402 . In this embodiment, a cooling solution will cool not only the multi-chip processor but also inductors  430 . 
       FIG. 11  shows a bottom side perspective view of a cooling solution that is a cold plate cooling solution with multiple floating heat transfer surface.  FIG. 12  shows the cooling solution incorporated on assembly  400  described with reference to  FIG. 10  with a lower portion showing a cross-section through lines D-D′. Referring to  FIG. 11  and  FIG. 12 , the cooling solution includes cold plate  475  having a first surface including inlet conduit  478  for a coolant to be introduced into a body of the cold plate outlet conduit  479  for coolant removal. Cold plate  475  includes channels therein for the distribution of a fluid between inlet conduit  478  and outlet conduit  479 . 
     In one embodiment, where cold plate  475  is connected to assembly  400 , the cold plate is justified to IHS  420 . As illustrated, companion chip  450  and its associated IHS  455  as well as inductors  430  are at a different Z-height than companion chip  450  and its associated IHS  455  and inductors  430 . In this case, each of the companion chip and inductors have a z-height that is less than a z-height of die  410  and its associated IHS. Referring to  FIG. 11 , in one embodiment, a cold plate  475  includes floating heat transfer surfaces on a backside of the cold plate (a side opposite conduit  478  and conduit  479 ).  FIG. 11  shows portion  472  positioned in a cavity  471  in an area of cold plate  475  corresponding to an area of companion chip  450  and portion  472 B in cavity  471 B of the cold plate in an area corresponding to an area of assembly  400  occupied by inductors  430 . Each portion  472 A and  472 B may be biased away from cold plate  475  by a spring (spring  473 ) between the cold plate and portion  472 A and portion  472 B respectively as described above.  FIG. 11  also shows heat pipes formed in channels in a base or backside of cold plate  475 . Heat pipe  4750 A, heat pipe  4750 B and heat pipe  4750 C are positioned in channels within the cold plate. Heat pipe  4750 A is connected to portion  472 A and can move in a z-direction with portion  472 A. Heat pipe  4750 C is connected to portion  472 B and can likewise move in a z-direction with portion  472 B. In this example, portion  472 A is used to cool companion chip  450  of a multi-chip package assembly while portion  472 B is used to cool an array of voltage regulator components located adjacent to the processor package. 
     Advantages of a single heat sink base with one or more adjustable heat transfer surfaces include a relatively cost efficient cooling solution design and maximizing cooling efficiency of multiple components by pooling (or sharing) a cooling solution volume of multiple components thereby increasing the overall power capability of each component and/or reducing the component operating temperatures. In addition, the floating heat transfer surfaces are self-adjusting to multiple height surfaces (multiple z-height possibilities) to minimize TIM 1  and TIM 2  and therefore increase a power capability and/or reduce temperature of a device. The configuration as described also allows continued use of existing TIM 2  materials and minimizes the air flow pressure drop through a cooling solution, thus increasing overall air flow (e.g., efficient fan operation point) thereby maximizing thermal performance. The adjustable load per component further translates to a robust cooling solution. 
     Embodiments of the present disclosure may be implemented into a computing device using any suitable hardware and/or software to configure as desired.  FIG. 13  schematically illustrates computing device  500  that includes an IC package assembly (e.g., multi-chip package) connected with a heat removal assembly as described herein, in accordance with some embodiments. Computing device  500  may be a desktop computer, a server system, a supercomputer, a high-performance computing system, a mobile device or a handheld reader. 
     In one embodiment, computing device  500  is a device that includes system bus  520  to electrically connect the various components of computing device  500 . System bus  520  is a single bus or any combination of busses according to various embodiments. Computing device  500  includes voltage source  530  that provides power to integrated circuit  510 . In some embodiments, voltage source  530  supplies current to integrated circuit  510  through system bus  520 . 
     Integrated circuit  510  is electrically connected to system bus  520  and includes any circuit, or combination of circuits according to an embodiment. In one embodiment, integrated circuit  510  includes processor  512  that can be of any type. As used herein, processor  512  can include any type of circuit such as, but not limited to, a microprocessor, a microcontroller, a graphics processor, a digital signal processor or another processor. In one embodiment, static random access memory (SRAM) embodiments are found in memory caches of the processor. Processor  512  of computing device  500  may be packaged in an IC package assembly (e.g., multichip package) connected with a heat removal assembly as described herein. For example, processor  512  may be a die of a die package that is connected with a heat removal assembly as described herein and mounted on the circuit board (e.g., a motherboard). Other suitable configurations may be implemented in accordance with embodiments described herein. The term “processor” may refer to any device or portion of a device that processes electronic data from registers and/or memory to transform that electronic data into other electronic data that may be stored in registers and/or memory. Other types of circuits that can be included in integrated circuit  510  in, for example, a multichip package assembly are one or more of a custom circuit or an application-specific integrated circuit (ASIC), such as communications circuit  514  for use in wireless devices such as cellular telephones, smart phones, pagers, portable computers, two-way radios, and similar electronic systems, or a communications circuit for servers. In one embodiment, a multichip package assembly of integrated circuit  510  includes on-die memory  516  such as SRAM. In one embodiment, integrated circuit  510  includes embedded on-die memory  516  such as embedded dynamic random access memory (eDRAM). 
     In one embodiment, integrated circuit  510  is complemented with subsequent integrated circuit  511 . Useful embodiments include dual processor  513  and dual communications circuit  515  and dual on-die memory  517  such as SRAM. In one embodiment, dual integrated circuit  510  includes embedded on-die memory  517  such as eDRAM. Devices of integrated circuit  511 , in one embodiment, are packaged in an IC package assembly (e.g., multichip package) connected with a heat removal assembly as described herein. 
     In one embodiment, computing device  500  also includes external memory  540  that in turn may include one or more memory elements suitable to the particular application, such as main memory  542  in the form of RAM, one or more hard drives  544 , and/or one or more drives that handle removable media  546 , such as diskettes, compact disks (CDs), digital variable disks (DVDs), flash memory drives, and other removable media known in the art. External memory  540  may also be embedded memory  548  such as the first die in a die stack, according to one embodiment. 
     In one embodiment, computing device  500  also includes display device  550 , audio output  560 . In one embodiment, computing device  500  includes an input device such as controller  570  that may be a keyboard, mouse, trackball, game controller, microphone, voice-recognition device, or any other input device that inputs information into the computing device  500 . In one embodiment, input device  570  is a camera. In one embodiment, input device  570  is a digital sound recorder. In one embodiment, input device  570  is a camera and a digital sound recorder. 
     Examples 
     Example 1 is an apparatus including a primary device and at least one secondary device coupled in a planar array to a substrate; a heat exchanger disposed on the primary device and on the at least one secondary device, wherein the heat exchanger includes at least one portion disposed over an area corresponding to the primary device or the at least one second device including a deflectable surface; and at least one thermally conductive conduit coupled to the heat exchanger and the at least one portion. 
     In Example 2, the heat exchanger of the apparatus of Example 1 includes a heat sink including an indivisible fin structure. 
     In Example 3, the heat exchanger of the apparatus of Example 1 or 2 includes a heat sink including an indivisible heat sink base. 
     In Example 4, the heat sink base of the apparatus of Example 3 includes a surface that defines a cavity, the apparatus further including a heat sink base portion in the cavity that defines the deflectable surface. 
     In Example 5, the heat sink base of the apparatus of Example 4 includes a first surface coupled to a fin structure and a second surface opposite the first surface, wherein the second surface defines the cavity. 
     In Example 6, the second surface of the apparatus of Example 5 defines at least one channel separate from the cavity, the apparatus further including a heat pipe disposed in the at least one channel, wherein the heat pipe extends into the heat base portion and is coupled to the heat sink base portion. 
     In Example 7, the heat pipe of the apparatus of Example 6 is coupled to the second surface of the heat sink base. 
     In Example 8, the heat pipe of the apparatus of Example 7 includes a first end and the first end is coupled to second surface of the heat sink base. 
     Example 9 is a system including a circuit board; a plurality of dice mounted on the circuit board; a heat exchanger positioned on the plurality of dice, the heat exchanger including at least one floating section operable to move in a direction toward or away from at least one of the plurality of dice; and at least one thermally conductive conduit disposed in a channel of the heat exchanger and connected to the at least one floating section. 
     In Example 10, the heat exchanger of the system of Example 9 includes a heat sink including an indivisible fin structure. 
     In Example 11, the heat exchanger of the system of Example 9 or 10 includes a heat sink including an indivisible heat sink base. 
     In Example 12, the heat sink base of the system of Example 11 includes a surface that defines a cavity, wherein a heat sink base portion is disposed in the cavity and defines the floating section. 
     In Example 13, the heat sink base of the system of Example 12 includes a first surface coupled to a fin structure and a second surface opposite the first surface, wherein the second surface defines the cavity. 
     In Example 14, the thermally conductive conduit of the system of Example 13 is coupled to the second surface of the heat sink base. 
     In Example 15, the thermally conductive conduit of the system of Example 14 includes a first end and the first end is coupled to second surface of the heat sink base. 
     Example 16 is a method including placing a heat exchanger on a multi-chip package, the heat exchanger including the heat exchanger including at least one floating section operable to move in a direction toward or away from at least one of the plurality of dice and at least one thermally conductive conduit disposed in a channel of the heat exchanger and connected to the at least one floating section; and coupling the heat exchanger to the multi-chip package. 
     In Example 17, the heat exchanger of the method of Example 16 includes a heat sink including an indivisible fin structure. 
     In Example 18, the heat exchanger of the method of Example 16 or 17 includes a heat sink including an indivisible heat sink base. 
     In Example 19, the heat sink base of any of the methods of Examples 16-18 includes a surface that defines a cavity, wherein a heat sink base portion is disposed in the cavity and defines the floating section. 
     In Example 20, a multi-chip package assembly is made by any of the methods of Examples 16-19. 
     Various embodiments may include any suitable combination of the above-described embodiments including alternative (or) embodiments of embodiments that are described in conjunctive form (and) above (e.g., the “and” may be “and/or”). Some embodiments may include one or more methods of removing heat from a multi-chip package and/or actions related to providing and/or fabricating a heat removal assembly as described herein. Furthermore, some embodiments may include one or more articles of manufacture (e.g., non-transitory computer-readable media) having instructions, stored thereon, that when executed result in actions of any of the above-described embodiments. Moreover, some embodiments may include apparatuses or systems having any suitable means for carrying out the various operations of the above-described embodiments. 
     The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various implementations of the invention.