Woven pyrolytic graphite sheets for heat diffusion

Abstract

A heat spreading element is provided, the heat spreading element including first and second pyrolytic graphite sheets (PGS) arranged to form an opening between their respective proximal ends, and a woven PGS including a first section arranged above the first PGS, a second section arranged below the second PGS, and a woven section extending through the opening between the proximal ends of the first and second sections.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Patent Application No. 63 / 426,567, filed November 18, 2022, which is incorporated by reference in its entirety. [Background technology]

[0002] The present disclosure relates to heat spreading, and more particularly to heat spreading using woven pyrolytic graphite sheets (PGS).

[0003] A heat spreader is an assembly used to transfer heat generated by an electronic device or module in a first direction away from the electronic device or module and spread the heat in a second direction. In some cases, the heat spreader includes a module, a cold plate or heat exchanger, and a heat spreading element interposed between the module and the cold plate. The heat spreading element transfers the heat generated by the module to the cold plate, spreading the heat in the process.

[0004] In conventional heat spreaders, the heat spreading element is provided by a monolithic copper spreader. These monolithic copper spreaders tend to be heavy. Therefore, conventional heat spreaders that include a monolithic copper spreader also tend to be heavy. Summary of the Invention

[0005] According to one aspect of the present disclosure, a heat spreading element is provided, the heat spreading element including first and second pyrolytic graphite sheets (PGS) arranged to form an opening between their respective proximal ends, and a woven PGS including a first section disposed above the first PGS, a second section disposed below the second PGS, and a woven section extending through the opening between the proximal ends of the first and second sections.

[0006] According to additional or alternative embodiments, at least one of the first and second PGS and the woven PGS comprises multiple PGS layers.

[0007] According to additional or alternative embodiments, at least one or more of the first, second, and woven PGSs comprise a woven structure.

[0008] According to additional or alternative embodiments, the heat spreading element further includes at least one of: an additional first PGS disposed between the first PGS, the first section of the woven PGS, and an additional second PGS disposed above the second PGS; and an additional second PGS disposed between the second PGS, the second section of the woven PGS, and the additional first PGS below the first PGS.

[0009] According to additional or alternative embodiments, the heat spreading element further includes an additional first PGS disposed between the first PGS, the first section of the woven PGS, and an additional second PGS disposed above the second PGS, and an additional second PGS disposed between the second PGS, the second section of the woven PGS, and the additional first PGS below the first PGS.

[0010] According to additional or alternative embodiments, the first section of the woven PGS is parallel to the first PGS, the second section of the woven PGS is parallel to the second PGS, and the woven section of the woven PGS is angled relative to the first and second sections.

[0011] According to additional or alternative embodiments, the first section of the woven PGS is parallel to the first PGS, the second section of the woven PGS is parallel to the second PGS, and the woven section of the woven PGS is perpendicular to the first and second sections.

[0012] According to additional or alternative embodiments, the first and second PGS are each arranged to form a plurality of openings between their respective proximal ends, and the woven PGS includes a plurality of woven sections each extending through a corresponding one of the plurality of openings.

[0013] According to one aspect of the present disclosure, a heat spreading element is provided, the heat spreading element including first and second pyrolytic graphite sheets (PGS) arranged to form an opening between their respective proximal ends, and a plurality of woven PGSs, each of the plurality of PGSs including a first section disposed above the first PGS, a second section disposed below the second PGS, and a woven section extending through the opening between the proximal ends of the first and second sections.

[0014] According to additional or alternative embodiments, at least one of the first and second PGS and the plurality of interwoven PGS comprises multiple PGS layers.

[0015] According to additional or alternative embodiments, the first and second PGS and at least one or more of the plurality of woven PGSs comprise a woven structure.

[0016] According to additional or alternative embodiments, the heat spreading element includes at least one of an additional first PGS disposed between the first PGS and the first section of the plurality of woven PGSs and above the second PGS, and an additional second PGS disposed between the second PGS and the second section of the plurality of woven PGSs and above the first PGS.

[0017] According to additional or alternative embodiments, the heat spreading element further includes an additional first PGS disposed between the first PGS and the first section of the plurality of woven PGSs and above the second PGS, and an additional second PGS disposed between the second PGS and the second section of the plurality of woven PGSs and above the first PGS.

[0018] According to additional or alternative embodiments, a first section of the plurality of woven PGS is parallel to the first PGS, a second section of the plurality of woven PGS is parallel to the second PGS, and an woven section of the plurality of woven PGS is angled relative to the first and second sections of the plurality of woven PGS.

[0019] According to additional or alternative embodiments, a first section of the plurality of interwoven PGSs is parallel to the first PGS, a second section of the plurality of interwoven PGSs is parallel to the second PGS, and an interwoven section of the plurality of interwoven PGSs is perpendicular to the first and second sections of the plurality of interwoven PGSs.

[0020] According to additional or alternative embodiments, the first and second PGSs are each arranged to form a plurality of openings between their respective proximal ends, and the plurality of woven PGSs includes a plurality of woven sections each extending through a corresponding one of the plurality of openings.

[0021] According to one aspect of the present disclosure, a sandwich structure for an electronic assembly is provided, the sandwich structure including: a core assembly including first and second sections defining an opening between proximal ends thereof; a first pyrolytic graphite sheet (PGS) disposed below the first section of the core assembly; a second PGS disposed above the second section of the core assembly; and an interwoven PGS including the first section disposed above the first section of the core assembly, the second section disposed below the second section of the core assembly, and the interwoven PGS extending through the opening between the proximal ends of the first and second sections.

[0022] According to additional or alternative embodiments, the woven PGS is provided as an encapsulated, annealed PGS.

[0023] According to additional or alternative embodiments, at least one or more of the first, second, and woven PGSs comprise a woven structure.

[0024] According to additional or alternative embodiments, the sandwich structure further includes clamping plates that sandwich the core assembly, the first and second PGS, and the woven PGS, a clamping element that clamps the clamping plates together, and an electronic device disposed on one of the clamping plates and including a mounting boss that extends into the core assembly.

[0025] Further features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the present disclosure are described in detail herein and are considered part of the claimed technical concept. For a better understanding of the present disclosure, together with its advantages and features, please refer to the description and drawings. [Brief explanation of the drawings]

[0026] For a more complete understanding of the present disclosure, reference is now made to the following brief description taken in conjunction with the accompanying drawings and detailed description, wherein like reference characters represent like parts, and wherein:

[0027] [Figure 1] 1 is a schematic side view of a heat spreading element according to an embodiment. [Figure 2] 1 is a schematic side view of a heat spreader with a heat spreading element according to an embodiment. [Figure 3] 3 is a graphical illustration of an assembly of the heat spreader and heat spreading element of FIG. 2 according to an embodiment. [Figure 4] 1 is a schematic side view of a heat spreader with a heat spreading element and a cross section according to an embodiment. [Figure 5] 1 is a schematic side view of a heat spreader with a heat spreading element according to an embodiment. [Figure 6] 1 is a schematic side view of a heat spreader with a heat spreading element according to an embodiment. [Figure 7]1 is a schematic side view of a heat spreader with a heat spreading element according to an embodiment. [Figure 8] 1 is a flow chart illustrating a method for assembling a heat spreader according to an embodiment. [Figure 9A] FIG. 1 is a side schematic view of a woven pyrolytic graphite sheet having a single woven layer according to an embodiment. [Figure 9B] FIG. 9B is an enlarged view of the circled portion of FIG. 9A according to an embodiment. [Figure 10] FIG. 1 is a side schematic view of a woven pyrolytic graphite sheet having multiple woven sections according to an embodiment. [Figure 11] FIG. 1 is a side schematic view of a woven pyrolytic graphite sheet having multiple woven layers according to an embodiment. [Figure 12] FIG. 1 is a side view of a sandwich structure in which interwoven pyrolytic graphite sheets are included for heat spreading according to an embodiment. [Figure 13] 1A and 1B are top and in-plane views, respectively, of an interwoven sheet of pyrolytic graphite according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0028] As described below, the woven structure of continuous pyrolytic graphite sheets (PGS) creates a spreader-via effect that efficiently spreads heat in all directions (3D spreader). Horizontal sheets rotate vertically to spread heat locally in the sheet plane while also spreading heat across the entire thickness. This results in quasi-isotropic thermal conductivity properties from PGS sheets with only two preferred directions of thermal conductivity. The number of interwoven layers can be optimized to produce different effective in-plane and through-thickness thermal conductivity values. Furthermore, PGS can be integrated into high-strength sandwich structures to provide high thermal conductivity in the x-, y-, and z-directions. Slots or round holes can be cut into the face sheets of the core assembly to allow the PGS to pass between the surfaces and effectively function as conductive vias. Top and bottom clamps compress the PGS, spreading heat throughout the structure. The device conducts heat through the base plate into the sheet metal clamp and transfers load directly to the sandwich composite by passing through the clamp and PGS layer, thus decoupling thermal and structural features.

[0029] Referring to FIG. 1 , a heat spreading element 101 is provided, which includes a compressible PGS 110 and a rigid PGS 120. The rigid PGS 120 are alternately arranged with the compressible PGS 110. At least one of the compressible PGS 110 and the rigid PGS 120 exhibits an in-plane thermal conductivity of greater than about 1000 W / mK. The compressible PGS 110 and the rigid PGS 120 have a much lower density than a metallic material such as copper. For example, the density of the rigid PGS 120 may be less than about 10% of the density of the metallic material. The density of the compressible PGS 110 may be less than about 10%, or even less than 5%, of the density of the metallic material. The compressible PGS 110 and the rigid PGS 120 can be compressed together in an interleaving direction A, for example, by a clamp 130. This compression effectively activates the in-plane thermal conductivity of the compressible PGS 110 and the rigid PGS 120, so that the heat spreading element 101 can realize the transfer of heat in a first direction (i.e., interleaving direction A) and spread heat in a second direction (i.e., in-plane direction B).

[0030] According to an embodiment, the rigid PGS 120 may have a density of about 1200-1300 kg / m 3 , and the compressible PGS 110 may have a sponge-like nature with a density of about 400-500 kg / m 3 .

[0031] Referring to FIG. 2 , a heat spreader 201 is provided. The heat spreader 201 includes a module 210 including electronic devices 211 that generate heat during operation, a heat exchanger or cold plate (hereinafter referred to as a “cold plate”) 220 configured to absorb and dissipate the heat generated by the electronic devices 211, a heat spreading element 230, and a clamp 240. The heat spreading element 230 includes a compressible PGS 231 and a rigid PGS 232 alternately arranged with the compressible PGS 231. At least one of the compressible PGS 231 and the rigid PGS 232 exhibits an in-plane thermal conductivity greater than approximately 1000 W / mK. The compressible PGS 231 and the rigid PGS 232 have a much lower density than a metallic material such as copper. For example, the density of the rigid PGS 120 may be less than approximately 10% of the density of the metallic material. The density of the compressible PGS 110 may be about 10% less than the density of the metallic material, and in some cases less than 5%.

[0032] As mentioned above, according to an embodiment, the rigid PGS 232 may have a density of about 1200-1300 kg / m 3 , and the compressible PGS 231 may have a sponge-like nature with a density of about 400-500 kg / m 3 .

[0033] The heat spreading element 230 is interposed between the module 210 and the cold plate 220 to transfer heat generated by the electronics 211 from the module 210 to the cold plate 220 in a first direction (i.e., an interleaving direction A relative to the interleaving direction of the compressible PGS 231 and the rigid PGS 232). The heat spreading element 230 also spreads heat in a second direction transverse to the first direction (i.e., an in-plane direction B of the compressible PGS 231 and the rigid PGS 232). The clamp 240 may include a screw 241 that can engage with at least the cold plate 220 to draw the cold plate 220 toward the module 210. The clamp 240 may alternatively include or be equipped with various other configurations that serve to draw the cold plate 220 toward the module 210. In either case, clamp 240 serves to clamp heat spreading element 230 between module 210 and cold plate 220, compressing compressible PGS 231 and rigid PGS 232 in a first or interleaving direction A. (Although FIG. 3 illustrates only compressible PGS 231 being compressed, this is for clarity and is not necessarily the case.) This compression of compressible PGS 231 and rigid PGS 232 effectively activates the in-plane thermal conductivity of compressible PGS 231 and rigid PGS 232.

[0034] According to an embodiment, the clamp 240 can be used to compress the compressible PGS 231 and the rigid PGS 232 to adjust the contact resistance between the compressible PGS 231 and the rigid PGS 232, thereby optimizing the overall heat transfer capacity of the heat spreading element 230 and optimizing the heat transfer capacity and in-plane thermal conductivity of the compressible PGS 231 and the rigid PGS 232.

[0035] It should be understood that, according to further or alternative embodiments, the compressible PGS 231 and the rigid PGS 232 need not be interleaved with one another in a 1:1 arrangement, and other configurations are possible, including configurations where only the compressible PGS 231 is provided, and / or where multiple compressible PGSs 232 are interleaved with a single rigid PGS 232.

[0036] 2, the heat spreader 201 can also include a monolithic metal element 250 interposed between the module 210 with the heat spreading element 230 and the cold plate 220. The monolithic metal element 250 can be formed of a metallic material such as copper or other suitable metal or metal alloy. The monolithic metal element 250 can be provided in a variety of configurations, but is typically provided as a single, integral element formed to define a pocket 251 in which the heat spreading element 230 can be positioned. In this sense, the monolithic metal element 250 can also engage with and be engaged by the clamp 240.

[0037] 2, the heat spreader 201 may also include a seal 245. The seal 245 may be of any size, shape, and dimension for use in the heat spreader 201. In some, but not all, cases, the seal 245 may be positioned and configured to prevent moisture from entering the heat spreading element 230. In some other cases, the seal 245 may also be positioned and configured to prevent moisture from flowing around the clamp 240 and then entering the heat spreading element 230.

[0038] 3 , according to an embodiment, the height H1 of the pocket 251 may be less than the height H2 of the heat spreading element 230 before the compressible PGS 231 and the rigid PGS 232 are compressed. Therefore, as described above, the height H1 of the pocket 251 can be adjusted together with the clamp 240 to compress the compressible PGS 231 and the rigid PGS 232 and optimize the heat transfer capability of the heat spreading element 230. That is, when the compressible PGS 231 and the rigid PGS 232 are compressed from the height H2 of the pocket 251 to the height H1, the degree of compression optimizes the heat transfer capability of the heat spreading element 230.

[0039] According to an embodiment, the degree of compression may be about 5-60% of the height H2.

[0040] The compressibility of the compressible PGS 231 can provide matching of coefficient of thermal expansion (CTE) mismatches between at least two or more of the module 210, the monolithic metal element 250, the rigid PGS 232, and the cold plate 220.

[0041] Referring to FIG. 4 and according to further embodiments, the heat spreading element 230 of FIGS. 2 and 3 can be provided in hybrid configurations, arrangements, and organizations. For example, as shown in FIG. 4, the heat spreading element 230 can include a compressible PGS 231, a rigid PGS 232, and a cross section 401. This cross section 401 can be, but need not be, provided within the heat spreading element 230 and can include the compressible PGS 231 and the rigid PGS 232. The compressible PGS 231 and the rigid PGS 232 of the cross section 401 can be oriented transversely or perpendicularly or otherwise rotated relative to the rest of the heat spreading element 230. In this way, the cross section 401 can function like a heat spreading via in the thickness direction (in addition to the in-plane heat spreading of the compressible PGS 231 and the rigid PGS 232). The compressible PGS 231 and rigid PGS 232 of the cross section 401 are compressible (i.e., by the rest of the heat spreading element 230), and therefore can provide a high degree of in-plane heat transfer between the module 210 and the cold plate 220. This cross section 401 can be placed at or near a hot spot of the module 210.

[0042] 4, the cross section 401 is shown as being sandwiched between the compressible pyrolytic graphite sheet 231 and the rigid pyrolytic graphite sheet 232, but it should be understood that this is not required and other embodiments are possible. For example, the cross section 401 could be in direct contact with one or both of the cold plate 220 and the monolithic metal element 250.

[0043] 5-7, according to further embodiments, the monolithic metal element 250 can be formed such that the pocket 251 can have a number of different configurations. For example, while the pocket 251 in FIGS. 2 and 3 is adjacent to the cold plate 220, the pocket 251 could be adjacent to the module 210 (see FIG. 5), the pocket 251 could be sandwiched on either side by portions 601 of the monolithic metal element 250 (see FIG. 6), or the pocket 251 could extend the entire distance between the module 210 and the cold plate 220 (see FIG. 7).

[0044] Referring to FIG. 8 , a method for assembling a heat spreader, such as the heat spreader 201 described above, is provided. As shown in FIG. 8 , the method includes alternating rigid thermal PGS and compressible PGS to form a heat spreading element for achieving heat transfer and heat spreading (block 801) and compressing the compressible PGS and rigid PGS in a heat transfer direction (block 802). According to an embodiment, the method may further include interposing the heat spreading element between the module and the cold plate to achieve heat transfer from the module to the cold plate in a first direction and to spread heat in a second direction transverse to the first direction (block 803). Furthermore, the compressing may include clamping the heat spreading element between the module and the cold plate to compress the compressible PGS and rigid PGS in the first direction (block 804). The method may further include interposing a monolithic metal element between the module with the heat spreading element and the cold plate (block 805).

[0045] 9A and 9B, a heat spreading element 901 is provided, the heat spreading element 901 including a first PGS 901 and a second PGS 920. The first and second PGSs 910 and 920 have proximal ends 911 and 921, respectively, and are positioned to form an opening 930 between the proximal ends 911 and 921. The heat spreading element 901 further includes a woven PGS 940. The woven PGS 940 includes a first section 941 positioned above the first PGS 910, a second section 942 positioned below the second PGS 920, and a woven section 943. The first and second sections 941 and 942 have proximal ends 9410 and 9420, respectively. The woven section 943 extends through the opening 930 between the proximal ends 9410 and 9420 of the first and second sections 941 and 942. An additional first PGS layer 951 can be disposed between the first PGS 910 and the first section 941 of the woven PGS 940, and an additional second PGS layer 952 can be disposed above the second PGS 920 to flatten the top surface of the heat spreading element 901. Similarly, an additional second PGS layer 962 can be disposed between the second PGS 920 and the second section 942 of the woven PGS 940, and an additional first PGS layer 961 can be disposed below the first PGS 941 to flatten the bottom surface of the heat spreading element 901. As shown in FIG. 9B, at least one of the first PGS 910, the second PGS 920, and the woven PGS 940 (as well as the additional first PGS layers 951, 961 and the additional second PGS layers 952, 962) can include multiple PGS layers 950.

[0046] 9A and 9B can be characterized in that a first section 941 of the woven PGS 940 is parallel to the first PGS 910, a second section 942 of the woven PGS 940 is parallel to the second PGS 920, and a woven section 943 of the woven PGS 940 is angled or perpendicular to the first and second sections 941 and 942. However, it should be understood that other embodiments exist and are encompassed within the present disclosure.

[0047] As described above, the first PGS910, the second PGS920, and the interwoven PGS940 have a strength of about 428 to 1,200 kg / m 3 At a density of about 1000 w / mK, or greater than about 400-1500 w / mK, the first and second PGSs 910 and 920 exhibit high in-plane thermal conductivities along arrows A1 and A2. The woven PGS 940 similarly exhibits high in-plane thermal conductivities along arrows A3 and A4 for the first and second sections 941 and 942, and along arrow A5 for the woven section 943. Thus, while the heat spreading element 901 can spread heat in the in-plane direction, the heat spreading element 901 can also spread heat out-of-plane, or through the thickness, at the location of the woven section 943.

[0048] 10, although Figures 9A and 9B relate to a case in which the first PGS 910 and the second PGS 920 form a single opening 930 through which a single woven section 943 extends, the present disclosure is not limited thereto, and other embodiments exist. For example, as shown in Figure 10, the first PGS 910 and the second PGS 920 can be arranged to form multiple openings 930, with the multiple woven sections 943 each extending through a corresponding opening of the multiple openings 930. In this manner, the heat spreading element 901 can have multiple out-of-plane heat transfer points at the multiple openings 930 and the multiple woven sections 943.

[0049] Referring to FIG. 11 , a heat spreading element 1101 is provided. The heat spreading element 1101 is substantially similar to the heat spreading element 901 of FIGS. 9A and 9B , and similar features need not be described again. The heat spreading element 1101 includes first and second PGSs 1110 and 1120 arranged to form an opening 1130 between their respective proximal ends, and a plurality of interwoven PGSs 1140. Each of the plurality of interwoven PGSs includes a first section 1141 disposed above the first PGS 1110, a second section 1142 disposed below the second PGS 1120, and an interwoven section 1143. The interwoven section 1143 extends through the opening 1130 between the proximal ends of the first and second sections 1141 and 1142.

[0050] 12, a sandwich structure 1201 for an electronic assembly is provided. The sandwich structure 1201 includes a core assembly 1210, a first PGS 1220, a second PGS 1230, and an interwoven PGS 1240. The core assembly 1210 includes face sheets 12101 sandwiching a core 12102, and includes a first section 1211 and a second section 1212, formed to define an opening 1213 between the proximal ends of the first section 1211 and the second section 1212. The first PGS 1220 is disposed below the first section 1211 of the core assembly 1210. The second PGS 1230 is disposed above the second section 1212 of the core assembly 1210. The woven PGS 1240 may be provided as an encapsulated, annealed PGS and includes a first section 1241 disposed above the first section 1211 of the core assembly 1210, a second section 1242 disposed below the second section 1212 of the core assembly 1210, and a woven section 1243. The woven section 1243 extends through openings 1213 between the proximal ends of the first section 1241 and the second section 1242 to function as thermally conductive vias. The sandwich structure 1201 further includes clamping plates 1250 that sandwich the core assembly 1210, the first and second PGSs 1220 and 1230, and the woven PGS 1240, a clamping element 1251 that clamps the clamping plates 1250 together, and an electronic device 1252 that is disposed on one of the clamping plates 1250 and includes a mounting boss 1253 that extends into the core assembly 1210.

[0051] As described above, the first and second PGS1220 and 1230, and the woven PGS1240, have a strength of about 428 to 1,200 kg / m 3At a density of about 1000 w / mK, the sandwich structure 1201 exhibits an in-plane thermal conductivity of greater than about 400-1500 w / mK. Thus, the first and second PGSs 1220 and 1230 exhibit high in-plane thermal conductivity along arrows B1 and B2. The woven PGS 1240 similarly exhibits high in-plane thermal conductivity along arrows B3 and B4 for the first and second sections 1241 and 1242, and along arrow B5 for the woven section 1243. Thus, while the sandwich structure 1201 can spread heat in the in-plane direction, the sandwich structure 1201 can also spread heat out-of-plane, or through the thickness, at the location of the woven section 1243 (i.e., to transfer heat downward from the electronic device 1252).

[0052] 13A and 13B, any of the PGSs described herein, including, but not limited to, the first PGS 910, second PGS 920, and interwoven PGS 940 of FIGS. 9A, 9B, and 10, and the first and second PGSs 1110 and 1120 and interwoven PGS 1140 of FIG. 11, can be formed by a PGS weave structure itself. For example, as shown in FIG. 13A, a PGS 1300 for use in any of the embodiments described herein can be formed by a weave structure 1301 of individual PGS elements 1302. The weave structure 1301 can have any weave pattern, such as the crisscross or double-over-double pattern shown in FIG. 13. Furthermore, while the PGS element 1300 is composed of individual PGS elements 1302, it should be understood that non-PGS elements can be included in the weave structure 1301 to achieve specific mechanical or thermal properties. For example, nylon or Kevlar™ sheets can be interwoven into the woven structure 1301 to increase the overall strength of the PGS 1300. In either case, as shown in FIG. 13B, for each PGS 1300 in a given application, the individual PGS elements 1302 can generally occupy the same general plane P as the PGS 1300 as a whole.

[0053] A technical effect and advantage of the present disclosure is to provide a PGS spreader laminate structure that allows for the design of new composite materials with high effective thermal conductivity and low density. The incorporation of PGS material increases the effective through-thickness conductivity of the PGS laminate structure, thereby improving the spreading performance of designs utilizing lightweight PGS material. An additional technical effect and advantage of the present disclosure is to provide a solution for making traditional structural composites thermally conductive.

[0054] The corresponding structure, material, acts, and equivalents of all means or step-plus-function elements in the following claims are intended to include any structure, material, or acts for performing the function as specifically claimed in combination with other claimed elements. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limiting to the technical concepts in the disclosed form. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The selection and description of the embodiments was made to best explain the principles and practical applications of the present disclosure and to enable others skilled in the art to understand the present disclosure in various embodiments with various modifications suitable for the particular use intended.

[0055] While preferred embodiments of the present disclosure have been described, it should be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements that fall within the scope of the following claims, which should be interpreted to maintain the appropriate protection for the disclosure as originally described.

Claims

1. A heat spreading element, first and second pyrolytic graphite sheets (PGS) arranged to form an opening between their respective proximal ends; It is a woven PGS, a first section disposed above the first PGS; a second section disposed below the second PGS; a woven section extending through the opening between the proximal ends of each of the first and second sections; the woven PGS comprising: The heat spreading element.

2. The heat spreading element of claim 1 , wherein at least one of the first and second PGS and the woven PGS comprises multiple PGS layers.

3. The heat spreading element of claim 1 , wherein at least one or more of the first PGS, the second PGS, and the woven PGS comprise a woven structure.

4. an additional first PGS disposed between the first PGS, the first section of the woven PGS, and an additional second PGS disposed above the second PGS; an additional second PGS disposed between the second PGS, the second section of the woven PGS, and an additional first PGS below the first PGS; The heat spreading element of claim 1 , further comprising at least one of:

5. an additional first PGS disposed between the first PGS, the first section of the woven PGS, and an additional second PGS disposed above the second PGS; an additional second PGS disposed between the second PGS, the second section of the woven PGS, and an additional first PGS below the first PGS; The heat spreading element of claim 1 further comprising:

6. 2. The heat spreading element of claim 1, wherein the first section of the woven PGS is parallel to the first PGS, the second section of the woven PGS is parallel to the second PGS, and the woven section of the woven PGS is angled relative to the first and second sections.

7. 2. The heat spreading element of claim 1, wherein the first section of the woven PGS is parallel to the first PGS, the second section of the woven PGS is parallel to the second PGS, and the woven section of the woven PGS is perpendicular to the first and second sections.

8. the first and second PGSs are respectively arranged to form a plurality of openings between their respective proximal ends; the woven PGS comprises a plurality of woven sections each extending through a corresponding opening of the plurality of openings; The heat spreading element of claim 1 .

9. A heat spreading element, first and second pyrolytic graphite sheets (PGS) arranged to form an opening between their respective proximal ends; A plurality of interwoven PGSs, each of which comprises: a first section disposed above the first PGS; a second section disposed below the second PGS; a woven section extending through the opening between the proximal ends of each of the first and second sections; the plurality of interwoven PGSs comprising: The heat spreading element.

10. The heat spreading element of claim 9 , wherein at least one of the first and second PGS and the plurality of woven PGS comprises multiple PGS layers.

11. The heat spreading element of claim 9 , wherein at least one of the first and second PGS and the plurality of interwoven PGS comprises a woven structure.

12. an additional first PGS disposed between the first PGS and the first section of the plurality of interwoven PGSs and above the second PGS; an additional second PGS disposed between the second PGS and the second section of the plurality of interwoven PGSs and above the first PGS; The heat spreading element of claim 9 , further comprising at least one of:

13. an additional first PGS disposed between the first PGS and the first section of the plurality of interwoven PGSs and above the second PGS; an additional second PGS disposed between the second PGS and the second section of the plurality of interwoven PGSs and above the first PGS; The heat spreading element of claim 9 further comprising:

14. 10. The heat spreading element of claim 9, wherein the first section of the plurality of woven PGS is parallel to the first PGS, the second section of the plurality of woven PGS is parallel to the second PGS, and the woven section of the plurality of woven PGS is angled relative to the first and second sections of the plurality of woven PGS.

15. 10. The heat spreading element of claim 9, wherein the first section of the plurality of woven PGS is parallel to the first PGS, the second section of the plurality of woven PGS is parallel to the second PGS, and the woven section of the plurality of woven PGS is perpendicular to the first and second sections of the plurality of woven PGS.

16. the first and second PGSs are respectively arranged to form a plurality of openings between their respective proximal ends; the plurality of woven PGSs comprising a plurality of woven sections each extending through a corresponding opening of the plurality of openings; The heat spreading element of claim 9.

17. 1. A sandwich structure for an electronic assembly, comprising: a core assembly comprising first and second sections defining an opening between their proximal ends; a first pyrolytic graphite sheet (PGS) positioned below the first section of the core assembly; a second PGS positioned above the second section of the core assembly; and It is a woven PGS, a first section disposed above the first section of the core assembly; a second section disposed below the second section of the core assembly; a woven section extending through the opening between the proximal ends of each of the first and second sections; the woven PGS comprising: A sandwich structure comprising:

18. 18. The sandwich structure of claim 17, wherein the woven PGS is provided as encapsulated and annealed PGS.

19. 20. The sandwich structure of claim 17, wherein at least one or more of the first PGS, the second PGS, and the woven PGS comprise a woven structure.

20. a clamp plate that sandwiches the core assembly, the first and second PGS, and the woven PGS; a clamping element for clamping the clamping plates together; an electronic device disposed on one of the clamp plates and including a mounting boss extending into the core assembly; 20. The sandwich structure of claim 17, further comprising:

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