Thermal management using thermal interface resistance changes

Abstract

A thermal management system includes an integrated circuit having an active side including control circuitry and a backside including a first set of electrodes distributed across the backside. The thermal management system includes a heat exchanger having a surface including a second set of electrodes. The thermal management system includes a thermal interface material including thermally conductive particles suspended in a fluid. The thermal interface material is disposed between the backside of the integrated circuit and the surface of the heat exchanger. The control circuitry is configured to apply an electric field to the thermal interface material using a first electrode of the first set of electrodes and a second electrode of the second set of electrodes to excite at least some of the thermally conductive particles between the first electrode and the second electrode.

Description

Background Technology

[0001] Typically, thermal management techniques improve reliability and reduce or eliminate premature failures of integrated circuits (ICs) due to heat generated by the IC product. Technologies used to cool ICs (e.g., heat sinks, forced ventilation systems, fans, heat pipes, and thermoelectric devices) typically cool the entire IC product. Hot spots are relatively small areas or localized regions of an IC product that have a higher temperature compared to the rest of the product. By cooling the entire IC product, conventional thermal management techniques can lead to unnecessarily overcooling of ICs prone to hot spots. Therefore, techniques for localized cooling of hot spots in ICs are needed. Summary of the Invention

[0002] In at least one embodiment, a thermal management system includes an integrated circuit having an active side including control circuitry and a back side, the back side including a first set of electrodes distributed thereon. The thermal management system includes a heat exchanger having a surface including a second set of electrodes. The thermal management system includes a thermal interface material comprising thermally conductive particles suspended in a fluid. The thermal interface material is disposed between the back side of the integrated circuit and the surface of the heat exchanger. The thermal interface material is in contact with both the back side of the integrated circuit and the surface of the heat exchanger. The control circuitry is configured to apply an electric field to the thermal interface material using a first electrode from the first set of electrodes and a second electrode from the second set of electrodes to excite at least some of the thermally conductive particles between the first and second electrodes. In at least one embodiment, the electric field is a non-uniform electric field. In at least one embodiment, the electric field causes at least some of the thermally conductive particles to form a high thermal conductivity path of the thermal interface material between the first and second electrodes. The thermal resistance of the high thermal conductivity path is lower than that of a region of the thermal interface material having randomly distributed thermally conductive particles suspended in the fluid. In at least one embodiment, the first electrode is located near a hot spot location of the integrated circuit. In at least one embodiment, the electric field is generated using alternating current provided by the integrated circuit. In at least one embodiment, the electric field is an alternating current field having amplitude, frequency, waveform, and phase determined by the control circuit. In at least one embodiment, the radius, first dielectric constant, and first conductivity of the thermally conductive particles, and the values ​​of a second dielectric constant and a second conductivity of the fluid cause the thermally conductive particles in the fluid to link in response to the electric field. In at least one embodiment, the first electrode and the second electrode are an asymmetric electrode pair. In at least one embodiment, the control circuit is configured to select the first electrode from the first set of electrodes based on the hot spot location. In at least one embodiment, the thermal management system further includes a plurality of sensors configured to sense the local temperature of the integrated circuit. The hot spot location is identified based on temperature information provided by the plurality of sensors. In at least one embodiment, the hot spot location is identified based on workload information of the integrated circuit. In at least one embodiment, the control circuit is configured to periodically update the hot spot location and enable a third electrode in the first set of electrodes based on the updated hot spot location. In at least one embodiment, the control circuit includes a storage element and a processor configured to execute instructions stored in the storage element and executable by the processor to generate a signal that applies the electric field to the thermal interface material.

[0003] In at least one embodiment, a method for thermal management of an integrated circuit product includes selecting a first electrode from a first set of electrodes distributed on the back side of the integrated circuit and a second electrode from a second set of electrodes on the surface of a heat exchanger. The method includes applying an electric field to a thermal interface material using the first and second electrodes. The thermal interface material comprises thermally conductive particles suspended in a fluid. The thermal interface material is disposed between the back side of the integrated circuit and the surface of the heat exchanger. The thermal interface material is in contact with both the back side of the integrated circuit and the surface of the heat exchanger. The electric field excites at least some of the thermally conductive particles between the first and second electrodes. In at least one embodiment of the method, the electric field is a non-uniform electric field. In at least one embodiment of the method, the electric field causes at least some of the thermally conductive particles to align, thereby forming a high thermal conductivity path of the thermal interface material between the first and second electrodes. The thermal resistance of the high thermal conductivity path is lower than that of a region of the thermal interface material having randomly distributed thermally conductive particles suspended in the fluid. In at least one embodiment, the first electrode is located near a hot spot location of the integrated circuit. In at least one embodiment, the electric field is generated using alternating current. In at least one embodiment, the method further includes identifying hotspot locations of the integrated circuit and selecting the first electrode based on the hotspot locations. In at least one embodiment, the method further includes sensing a local temperature of the integrated circuit and identifying the hotspot locations based on the local temperature. In at least one embodiment, the hotspot locations are identified based on workload information. In at least one embodiment, the method further includes periodically updating the hotspot locations of the integrated circuit and enabling a third electrode in the first set of electrodes based on the updated hotspot locations. In at least one embodiment, the thermally conductive particles suspended in the fluid are electrically conductive particles. In at least one embodiment, the radius, first dielectric constant, and first conductivity of the thermally conductive particles, and the values ​​of a second dielectric constant and a second conductivity of the fluid, cause the thermally conductive particles in the fluid to link in response to the electric field.

[0004] In at least one embodiment, a method for manufacturing a thermal management system includes providing an integrated circuit having an active side including control circuitry and a back side, the back side including a first set of electrodes distributed on the back side. The method includes providing a heat exchanger having a surface including a second set of electrodes. The method includes providing a thermal interface material comprising thermally conductive particles suspended in a fluid. The thermal interface material is disposed between the back side of the integrated circuit and the surface of the heat exchanger. The thermal interface material is in contact with the back side of the integrated circuit and the surface of the heat exchanger. The control circuitry is configured to apply an electric field to the thermal interface material using a first electrode from the first set of electrodes and a second electrode from the second set of electrodes to excite at least some of the thermally conductive particles between the first and second electrodes. In at least one embodiment, the method further includes forming the first set of electrodes on the back side of the integrated circuit, forming a passivation layer on the surface of the heat exchanger, and forming a second set of electrodes electrically isolated from the heat exchanger by the passivation layer. In at least one embodiment, the radius, first dielectric constant, and first conductivity of the thermally conductive particles, and the values ​​of the second dielectric constant and second conductivity of the fluid, cause the thermally conductive particles in the fluid to link in response to the electric field. In at least one embodiment, the first electrode and the second electrode are an asymmetric electrode pair. Attached Figure Description

[0005] The invention can be better understood by referring to the accompanying drawings, and many of its objects, features and advantages will be apparent to those skilled in the art.

[0006] Figure 1 An exemplary power density diagram of an integrated circuit product in operation is shown.

[0007] Figure 2 It shows Figure 1 An exemplary cross-sectional view of an integrated circuit product.

[0008] Figure 3 A cross-sectional view of a thermal management system comprising a thermal interface material according to at least one embodiment of the present invention is shown, the thermal interface material having a thermal resistance that changes with the application of alternating current to electrodes.

[0009] Figure 4 A cross-sectional view of a thermal management system comprising a thermal interface material according to at least one embodiment of the present invention is shown, the thermal interface material having a thermal resistance that changes using a direct current applied to an asymmetric electrode pair.

[0010] Figure 5A plan view of the surface of a heat exchanger or integrated circuit product including electrodes, conforming to at least one embodiment of the present invention, is shown.

[0011] Figure 6 At least one embodiment conforming to the present invention is shown. Figure 5 A detailed view of the electrodes and the functional blocks used to provide associated control signals.

[0012] Figure 7 At least one embodiment conforming to the present invention is shown. Figure 3 A cross-sectional view of an integrated circuit product, the integrated circuit product including through-silicon vias.

[0013] Figure 8 At least one embodiment conforming to the present invention is shown. Figure 4 Functional block diagram of the active side of an integrated circuit product.

[0014] Figure 9 A plan view of the surface of a heat exchanger or integrated circuit product comprising electrodes arranged according to a power density diagram, conforming to at least one embodiment of the present invention, is shown.

[0015] Using the same reference numerals in different figures indicates similar or identical items. Detailed Implementation

[0016] refer to Figure 1 and Figure 2 Exemplary integrated circuit products (e.g., integrated circuit dies, multi-chip modules, or integrated circuit dies or multi-chip modules attached to an interposer or package substrate) include regions operating at different power densities. For example, regions 104 and 106 operate at a higher power density than region 103. Region 104 may have a higher power density at different times than region 106. Regions 104 and 106 generate associated hot spots on integrated circuit product 102. Exemplary thermal management system 100 includes a heat exchanger 110 (e.g., a heat sink, heat fin, package cap, or other heat transfer structure) in contact with the surface of the integrated circuit product (e.g., the back side of a flip-chip die, the back side of a substrate attached to the die) via a thermal interface material 108 between the heat exchanger 110 and the surface of the integrated circuit product 102. The heat exchanger 110 transfers heat energy from the high-temperature integrated circuit product 102 to another object (e.g., air) at a lower temperature.

[0017] Thermal interface material 108 fills the gap between the heat transfer surface of integrated circuit product 102 and heat exchanger 110 to improve heat transfer efficiency. In at least one embodiment, thermal interface material 108 is a fluid (e.g., non-curing polymer matrix, silicone-based fluid, polymerized oil) to which thermally conductive particles (e.g., silver, aluminum, alumina, zinc oxide, boron nitride) are added to increase the thermal conductivity of the compound (i.e., reduce thermal resistance). Typically, the thermally conductive particles are randomly dispersed throughout the fluid. Thermal interface material 108 has an effective thermal conductivity (e.g., 3 W / mK to 6 W / mK) that does not change substantially with time or operating conditions.

[0018] Thermal management technology increases the thermal conductivity of the thermal interface material in localized areas by arranging thermally conductive particles within the thermal interface material to create high thermal conductivity paths between the surface of the integrated circuit product and the surface of the heat exchanger. (Reference) Figure 3 The thermal interface material 208 is a compound comprising a fluid (e.g., a non-curing polymer matrix, a silicone-based fluid, a polymerized oil) and thermally conductive particles (e.g., silver, aluminum, alumina, zinc oxide, boron nitride). The fluid has a sufficiently low viscosity (e.g., less than 250 Pascals per second) to allow the thermally conductive particles to move within the fluid of the compound. In at least one embodiment of the thermal interface material 208, the thermally conductive particles are silver particles (e.g., microparticles or nanoparticles) having a thermal conductivity of approximately 406 W / (mK), but other embodiments include gold, copper, or aluminum particles. In one embodiment, the thermal interface material 208 has a thickness ranging from 20 μm to 100 μm. Metal-based thermal interface materials can be both conductive and capacitive. If a metal-based thermal interface material comes into contact with a circuit, the thermal interface material may cause the circuit to malfunction or be damaged. In at least one embodiment of the thermal interface material 208, other thermally conductive particles (e.g., micronized diamond particles with a high thermal conductivity of approximately 1000 W / mK) can be used as electrical insulators.

[0019] refer to Figure 3 and Figure 4In at least one embodiment, the thermal management system 200 uses dielectric electrophoresis to polarize neutral thermally conductive particles (i.e., thermally conductive particles) in the thermal interface material 208. The dielectric electrophoresis excites the particles, causing them to move or align multiple particles between the hot spot of the integrated product 202 and the heat exchanger 210 to form a high thermal conductivity path 216 (e.g., a heat sink, fin, or heat transfer structure) between the electrode 214 near the hot spot of the integrated product 202 and the electrode 212 of the heat exchanger 210. The thermal resistance of the high thermal conductivity path 216 is less than that of other portions of the thermal interface material 208 with randomly distributed thermally conductive particles. In at least one embodiment, the heat exchanger 210 has a smooth and flat contact surface for establishing thermal contact with the surface of the integrated product 202 (e.g., the back side of the integrated circuit die). In other embodiments, heat exchanger 210 includes a textured contact surface (e.g., a serrated surface) to increase the surface area for establishing thermal contact with another surface of integrated circuit product 202 (e.g., the back side of the integrated circuit die). An exemplary serrated surface creates electrode locations in the region of increased surface area. In some embodiments, heat exchanger 201 includes a contact surface comprising smooth regions and also includes textured regions near the intended hot spot locations. By activating (e.g., in-situ polarization), concentrating, or aligning the thermally conductive particles between the hot spots of integrated circuit product 202 and heat exchanger 210, the thermal management system 200 reduces the effective thermal resistance of the high thermal conductivity path between the hot spots of integrated circuit product 202 and heat exchanger 210 compared to the region of thermal interface material 208 with randomly distributed thermally conductive particles.

[0020] Typically, the dielectric electrophoretic motion of polarized neutral thermally conductive particles occurs in response to the force applied to the particles when they are subjected to a non-uniform electric field. The generation of the dielectric electrophoretic force depends on the shift of the electric field gradient. The electric field gradient can be generated by changing the phase of the electric field, using asymmetric electrodes (e.g., electrodes with different geometries, non-uniform shapes, or formed from different materials), or other suitable techniques.

[0021] In at least one embodiment of the thermal management system 200, the non-uniform electric field is a non-uniform alternating current (AC) electric field or a non-uniform direct current (DC) electric field. The force exerted by AC dielectric electrophoresis on the heat-conducting particles is controlled by adjusting field parameters (e.g., amplitude, frequency, waveform, wave symmetry, and phase). The sign and amplitude of the dipole induced in the heat-conducting particles are given by the real part of the Clausius-Mossotti function K:

[0022]

[0023] Where ε1 is the dielectric constant of the fluid, σ1 is the electrical conductivity of the fluid, ε2 is the dielectric constant of the thermally conductive particles, and σ2 is the electrical conductivity of the thermally conductive particles. It is the Maxwell-Wagner charge relaxation time, and ω is the AC field frequency.

[0024] Typically, when a high concentration of thermally conductive particles exists between electrodes, dielectric electrophoresis leads to structuring. In various implementations, particle sizes range from nanometers to micrometers. If the thermally conductive particles are sufficiently close, the dipoles induced within them interact. The thermally conductive particles align into chains along the field lines. The chaining force F... 链 Depends on the square of the field strength E 2 and the square of the particle radius r 2 :

[0025] F 链 =-Cπε1r 2 K 2 E 2 ,

[0026] The coefficient C ranges from 3 to >10. 3 This depends on the distance between the thermally conductive particles and the length of the chain. The bonding force acting on thermally conductive particles with similar electrical properties is positive and adsorbent. In at least one embodiment, the thermally conductive particles, the fluid, the concentration of the thermally conductive particles in the fluid, and the AC field parameters are selected to cause particle structuring or bonding in response to the AC or DC electric field generated by the selectively activated electrodes of the integrated circuit product 202 and the heat exchanger 210.

[0027] The thermal management system 200 applies an AC or DC signal to at least one selectively enabled electrode pair to generate an AC field or a DC field, respectively, on the thermal interface material 208. In some embodiments, the thermal management system uses the selectively enabled electrodes to apply charge pulses to induce small movements of thermally conductive particles in the thermal interface material 208, thereby enhancing heat transfer. Each selectively enabled electrode pair includes an electrode on the surface of the integrated circuit product 202 and an electrode on the surface of the heat exchanger 210. In embodiments of the thermal management system 200, an electrode 214 selected from a plurality of electrodes on the back side of the integrated circuit product 202 is asymmetrical with an electrode 212 of the heat exchanger 210. For example, electrode 214 has a different thickness or shape than electrode 212, even if both sets of electrodes are formed of the same material (e.g., thin-film conductor). In at least one embodiment, different numbers of electrodes are selected on the surfaces of the integrated circuit product 202 and the heat exchanger 210 to generate an asymmetric electric field on the thermal interface material 208. The thermal management system 200 selects at least one electrode on the surface of the heat exchanger 210 in contact with the thermal interface material 208 and at least one electrode on the surface of the integrated circuit product 202 in contact with the thermal interface material 208 to generate a non-uniform electric field, thereby causing some of the thermally conductive particles in the thermal interface material 208 to be excited, concentrated or aligned and form a high thermal conductivity path between the surfaces of the integrated circuit product 202 and the heat exchanger 210.

[0028] refer to Figure 5 In at least one embodiment, an array of thin-film electrodes 212 and associated electrical wiring (not shown) are formed on the surface of the integrated circuit product 202 (e.g., the back side of the integrated circuit product 202). The electrodes 212 are formed using conventional integrated circuit manufacturing techniques, such as forming a dielectric layer, forming one or more conductive layers (e.g., a metal layer or a redistribution layer), and patterning the conductive layers (e.g., applying photoresist, selectively exposing the photoresist using a scaled-down mask including a pattern of conductive pads, and removing unwanted material). It should be noted that the geometry, spacing, and shape of the electrodes may vary depending on the application.

[0029] refer to Figure 6 (It shows) Figure 5(A detailed view of a subset 606 of electrodes), selection circuit 602 receives a digital code SEL that identifies one or more of the electrodes to be selected to receive power from power supply 604 independently of the other electrodes. The unselected electrodes are coupled to ground or another power supply voltage. In at least one embodiment, selection circuit 602 is included on the surface of integrated circuit product 202 and receives the digital code SEL from the active side of integrated circuit product 202. In other embodiments, selection circuit 602 is included on the active side of integrated circuit product 200 and the selected electrode receives power from a selectively enabled power signal received from the active side of integrated circuit product 202. Reference Figure 7 In at least one embodiment, a through-silicon via (TSV) is used to receive control or power signals from the active side of integrated circuit product 202. The TSV 708 is a vertical interconnect structure that passes entirely through the die of integrated circuit product 202. For example, the TSV 708 is formed using wafer back-side photolithography, deep silicon etching, silicon dioxide etching with a photoresist mask (e.g., reactive ion etching (RIE)), sidewall insulating deposition (e.g., low-temperature plasma-enhanced chemical vapor deposition (PECVD), silicon dioxide deposition, and subsequent silicon dioxide RIE), and conductive material processing. In other embodiments, the active side of integrated circuit product 200 provides a digital code SEL to a digital signal interface, and an external conductor provides a digital code SEL to a port on the back side of integrated circuit product 200.

[0030] The heat exchanger 210 includes a second set of one or more electrodes. In at least one embodiment, the electrodes are formed on a passivation layer (e.g., silicon nitride). Although the first set of electrodes and the second set of one or more electrodes are described as including multiple electrodes, in at least one embodiment, the second set of electrodes includes only one electrode. In at least one embodiment, the heat exchanger 210 is a thermally and electrically conductive plate coupled to a ground node of a power supply and serving as the sole electrode in the second set of electrodes of the heat exchanger, and the thermal management system 200 selectively enables only the electrode in the first set of electrodes on the back side of the integrated circuit product 202.

[0031] refer to Figure 8In at least one embodiment, the integrated circuit product 202 includes a processor 402, a coprocessor 404, memory circuitry 406, 408, 410, and 412, an interface 416, and a thermal controller 414. In at least one embodiment, the processor 402 is a microprocessor, a central processing unit, a graphics processing unit, an accelerated processing unit, a digital signal processor, or other processing circuitry. In some embodiments, a separate thermal controller 414 is not included. In other embodiments, the thermal controller 414 is implemented using software (including firmware) executed on the processor 402 or the coprocessor 404, or by a combination of software and hardware. As described herein, the software may be encoded in memory 406, 408, 410, or 412, or at least one other tangible (i.e., non-transitory) computer-readable medium. As mentioned herein, tangible computer-readable media include at least magnetic disks, magnetic tapes, or other magnetic, optical, or electronic storage media.

[0032] In embodiments of the thermal management system 200, a thermal controller 414 generates a digital code SEL and transmits the digital code SEL or an associated selectively enabled power signal to the back side of the integrated circuit product 202. In some embodiments, the digital code SEL also includes an interface 416 transmitting a signal via an external signal to the heat exchanger 210 for selectively enabling at least one electrode in a second set of electrodes of the heat exchanger 210. In at least one embodiment, the thermal controller 414 includes a temperature sensor (e.g., a diode on the integrated circuit product 202) distributed on the active side of the integrated circuit product 202. The temperature sensor provides temperature information to the thermal controller 414 to identify hot spots in the integrated circuit product 202 during operation. In at least one embodiment, the thermal controller 414 determines the temperature difference between one area of ​​the integrated circuit product 202 and other areas of the integrated circuit product 210 and compares these temperature differences with a threshold temperature difference corresponding to a hot spot to detect a hot spot in the integrated circuit product 202.

[0033] refer to Figure 3 , Figure 4 and Figure 8In one embodiment, the thermal controller 414 uses workload information of the integrated circuit product 200 as a proxy for or supplement to temperature information to identify hot spots in the integrated circuit product 202. For example, the thermal controller 414 can use workload information (e.g., program flow information) of the processor 402 and coprocessor 404. If the workload information indicates that the coprocessor 404 is operating in a high-power mode, the thermal controller 414 enables one or more electrodes proximate to the coprocessor 404 to generate one or more corresponding high thermal conductivity paths (e.g., high thermal conductivity path 216 or high thermal conductivity path 218) between the hot spot generated by the coprocessor 404 and the heat exchanger 210 of the integrated circuit product 202. In one embodiment, the thermal controller 414 periodically performs hot spot detection and updates selected electrodes to change the location of the high thermal conductivity path between the hot spot and the heat exchanger 210 or to generate additional high thermal conductivity paths between additional hot spots and the heat exchanger 210. In at least one embodiment, thermal controller 414 receives information about which core of the multi-core integrated circuit is performing a workload, and thermal controller 414 updates selected electrodes to create a high thermal conductivity path between the hot spot associated with the core performing the workload and heat exchanger 210. Thermal controller 414 updates selected electrodes to create a high thermal conductivity path at another location performing the workload or disables said path and randomly disperses thermally conductive particles through a thermal interface material to uniformly cool all cores of the integrated circuit die.

[0034] If the program flow instructs the coprocessor 404 to operate in a low-power mode, the thermal controller 414 disables the associated electrodes of a previously enabled high thermal conductivity path. In one embodiment, the first set of electrodes on the back side of the integrated circuit product 202 is tailored for predetermined hot spots of the integrated circuit product 202, having a higher density in areas associated with higher power consumption and a lower density in areas associated with lower power consumption, such as... Figure 9 As shown. Although Figure 5 , Figure 6 and Figure 9 The electrodes are shown as square conductive pads, but in other embodiments, the electrodes have different geometries (e.g., rectangular, rhomboid, or irregular shapes).

[0035] Although thermal management systems have been described in embodiments in which dielectric electrophoretic forces are used to align thermally conductive particles suspended in a thermal interface material to reduce the thermal resistance of the path in the thermal interface material between the hot spot of integrated circuit product 202 and heat exchanger 210, those skilled in the art will understand that the teachings herein can be utilized in conjunction with electrophoresis, magnetophore migration of thermally conductive particles, or electrophoretic migration of thermally conductive particles to create a high thermal conductivity path in the thermal interface material between the hot spot of integrated circuit product 202 and heat exchanger 210. For example, in one embodiment, the thermal interface material 208 comprises magnetic thermally conductive particles (e.g., gold-coated iron oxide particles), and a magnetic field gradient causes magnetophore migration of the thermally conductive particles to form a path with a higher thermal conductivity than that of a fluid having randomly distributed thermally conductive particles. Implementations using electromagnetic electrophoresis employ electrodes or real magnets to generate a magnetic field that applies force to the particles to excite, translate, or align them to form a path with high thermal conductivity compared to the fluid having randomly distributed thermally conductive particles, due to the Lorenz force generated by simultaneously applying current and a magnetic field to the thermally conductive particles.

[0036] Therefore, thermal management techniques for cooling hot spots without overcooling other parts of integrated circuit products have been described. The description of the invention set forth herein is illustrative and is not intended to limit the scope of the invention as set forth in the appended claims. Variations and modifications may be made to the embodiments disclosed herein based on the description set forth herein without departing from the scope of the invention as set forth in the appended claims.

Claims

1. A thermal management system comprising: an integrated circuit having an active side comprising a control circuit and a back side comprising a first set of electrodes distributed on the back side; a heat exchanger having a surface comprising a second set of electrodes; and a thermal interface material comprising thermally conductive particles suspended in a fluid, the thermal interface material disposed between the back side of the integrated circuit and the surface of the heat exchanger, the thermal interface material in contact with the back side of the integrated circuit and the surface of the heat exchanger, wherein the control circuit is configured to apply an electric field to the thermal interface material using a first electrode of the first set of electrodes and a second electrode of the second set of electrodes to excite at least some of the thermally conductive particles between the first electrode and the second electrode such that a high thermal conductivity path of the thermal interface material is formed between the first electrode and the second electrode, the high thermal conductivity path having a lower thermal resistance than a region of the thermal interface material having randomly distributed thermally conductive particles suspended in the fluid.

2. The thermal management system of claim 1, wherein the electric field is a non-uniform electric field.

3. The thermal management system of claim 1, wherein the electric field causes at least some of the thermally conductive particles to align, thereby forming the high thermal conductivity path of the thermal interface material between the first electrode and the second electrode.

4. The thermal management system of claim 1, wherein the first electrode is proximate to a hot spot location of the integrated circuit.

5. The thermal management system of claim 1, wherein the electric field is generated using alternating current provided by the integrated circuit.

6. The thermal management system of claim 1, wherein the electric field is an alternating current electric field having an amplitude, a frequency, a waveform, and a phase determined by the control circuit.

7. The thermal management system of claim 1, wherein values of a radius, a first dielectric constant, and a first electrical conductivity of the thermally conductive particles and a second dielectric constant and a second electrical conductivity of the fluid cause the thermally conductive particles in the fluid to chain in response to the electric field.

8. The thermal management system of claim 1, wherein the first electrode and the second electrode are an asymmetric pair of electrodes.

9. The thermal management system of claim 1, 2, 3, 4, 5, 6, 7, or 8, wherein the control circuit is configured to select the first electrode from the first set of electrodes based on a hot spot location, and wherein the thermal management system further comprises: a plurality of sensors configured to sense a local temperature of the integrated circuit, wherein the hot spot location is identified based on temperature information provided by the plurality of sensors, wherein the control circuit is configured to periodically update the hot spot location and enable a third electrode of the first set of electrodes in accordance with the updated hot spot location.

10. The thermal management system of claim 1, 2, 3, 4, 5, 6, 7, or 8, ​ wherein the control circuit is configured to select the first electrode from the first set of electrodes based on a hot spot location, and wherein the hot spot location is identified based on workload information of the integrated circuit, wherein the control circuit is configured to periodically update the hot spot location and enable a third electrode of the first set of electrodes according to the updated hot spot location.

11. A method for thermal management of an integrated circuit product, the method comprising: selecting a first electrode from a first set of electrodes distributed on a backside of an integrated circuit and a second electrode from a second set of electrodes of a surface of a heat exchanger; and applying an electric field across a thermal interface material using the first electrode and the second electrode, the thermal interface material comprising thermally conductive particles suspended in a fluid, the thermal interface material disposed between the backside of the integrated circuit and the surface of the heat exchanger, the thermal interface material in contact with the backside of the integrated circuit and the surface of the heat exchanger, the electric field exciting at least some of the thermally conductive particles between the first electrode and the second electrode such that a high thermal conductivity path of the thermal interface material is formed between the first electrode and the second electrode, the high thermal conductivity path having a thermal resistance lower than a region of the thermal interface material having randomly distributed thermally conductive particles suspended in the fluid.

12. The method of claim 11, wherein the electric field is a non-uniform electric field, and wherein the electric field causes at least some of the thermally conductive particles to align, thereby forming the high thermal conductivity path of the thermal interface material between the first electrode and the second electrode.

13. The method of claim 11 or 12, further comprising: identifying a hot spot location of the integrated circuit; sensing a local temperature of the integrated circuit; and periodically updating the hot spot location of the integrated circuit and enabling a third electrode of the first set of electrodes according to the updated hot spot location, wherein the first electrode is selected based on the hot spot location, and wherein the hot spot location is identified based on the local temperature.

14. The method of claim 11 or 12, further comprising: identifying a hot spot location of the integrated circuit; and periodically updating the hot spot location of the integrated circuit and enabling a third electrode of the first set of electrodes according to the updated hot spot location, wherein the first electrode is selected based on the hot spot location, and wherein the hot spot location is identified based on workload information.

15. The method of claim 11 or 12, wherein values of a radius, a first dielectric constant, and a first electrical conductivity of the thermally conductive particles and a second dielectric constant and a second electrical conductivity of the fluid cause the thermally conductive particles in the fluid to chain in response to the electric field.

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