JP4849758B2 - Method for forming reinforced articles - Google Patents

Description

[0001]
(Background of the Invention)
The present invention generally relates to an improved method of forming reinforced articles from composite materials. More particularly, the present invention is a thermally and / or electrically conductive material that is easily moldable and provides a conductivity several times greater than prior art molding methods even with known materials. The present invention relates to a method for forming an article. The present invention also provides a method of forming a structurally improved and reinforced article from a composite material. It should be understood that the term “reinforced article” refers to an article filled with any type of filler material, whether conductive, thermally conductive, or high strength. Accordingly, the methods of the present invention relate to electrically conductive compositions, thermally conductive compositions, and structurally reinforced compositions.
[0002]
In the electronics industry, it is well known to use metallic materials for thermal and conductive applications such as heat dissipation for cooling semiconductor device packages, grounding applications. For these applications, such as heat sinks, metal materials are generally machined or machined from bulk metal to the desired shape. However, such metallic conductive articles are generally very heavy, expensive to machine and susceptible to corrosion. Furthermore, the geometry of machined metal heat dissipation articles is very limited to the inherent limitations associated with machining or tooling processes. As a result, the desired form, for example, especially when it is known that a particular geometry achieves better thermal efficiency by its design but cannot be obtained due to limitations in machining metal articles. The requirement for the use of metallic materials that are machined into a severe limit on component design.
[0003]
It is widely known in the prior art that improving the overall geometry of a heat dissipating article can significantly increase the overall performance of the article, even if the materials are the same. Thus, the need for improved heat sink geometry and lower cost required an alternative to machining bulk metal materials. In order to meet this need, attempts have been made in the prior art to provide shaped compositions comprising conductive filler materials in order to provide the necessary thermal conductivity. The ability to form conductive composites allowed more complex part geometry designs to achieve improved performance of the part. Similarly, the conductivity of a given article can be significantly improved if it can be molded. For example, the shape and configuration can be significantly improved by molding the article to achieve improved conductivity. In addition, moldable composites of high structural integrity with high strength filler materials are also known.
[0004]
Prior art attempts have included using a polymer-based matrix to which is added a granular material such as boron nitride grains. Similarly, attempts have been made to provide polymer-based matrices with the addition of flaky filler material. In fact, these attempts can be molded into complex geometries, but still do not approach the desired level of performance in machined metal parts. It is known in the art that filler materials, particularly high aspect ratio filler materials, are aligned parallel to the flow path of the base matrix in the mold. Therefore, these conductive composite materials must be molded very accurately due to filler alignment problems during the molding process. This is a problem when the filler material is asymmetric or when the aspect ratio of thickness to filler length is 1: 1 or greater. Even with precise molding and design, the inherent problem of fluid turbulence, i.e. collision with the mold due to complex product geometry, makes the ideal placement of asymmetric fillers impossible and thus the composition The performance of is much lower than desired. This problem is exacerbated when the filler has an aspect ratio greater than 10: 1. This is a serious problem because fillers with aspect ratios up to 40: 1 are commonly used.
[0005]
Furthermore, since heat transfer is a bulk property rather than a direct path property such as electricity transfer, the entire matrix of the composition must be satisfactory. A direct path is necessary to conduct electricity. However, heat is transferred in bulk where the entire volume of the body is used for transfer. Thus, even though a high conductivity narrow conduit is provided through the much lower conductivity body, heat transfer is not as good as a body that is consistently near-limit conductivity throughout the body. Thus, the consistency of thermal conductivity across the matrix of the composite body is important for overall high thermal conductivity. Furthermore, proper alignment of the filled filler material within the polymer base, especially the high aspect ratio filler, is very important. When the composite is used for electrical conductivity, the placement of the filler in the composite is also very important in that the number of excessive interruptions in the filler makes electrical transmission inadequate.
[0006]
In view of the foregoing, there is a need for improved methods of forming reinforced articles made of composite materials that are thermally conductive and / or conductive. Similarly, there is a need for composite molded articles that contain or are reinforced with high strength filler materials for higher structural integrity. Furthermore, there is a need for a molding method that uses composite polymers and filler materials, i.e., can fully utilize the proper alignment and placement of filler materials with a base polymer matrix. Similarly, there is a need for a method that allows such polymers and high aspect ratio filler compositions to be easily formed into complex product geometries. Similarly, there is a need for a molding method to form articles that exhibit thermal and electrical conductivity as close as possible to pure metal conductive materials, while having relatively low manufacturing costs.
[0007]
(Summary of Invention)
The present invention maintains the advantages of prior art methods of forming reinforced articles from conductive plastic compositions. Furthermore, the present invention provides new advantages not found in the methods known to date and eliminates many of the disadvantages of such currently available methods.
[0008]
The present invention generally relates to thermally conductive articles having application specific to heat sink applications, particularly those where heat must be transferred from one area to another to prevent equipment failure. It is directed to a new and unique method of molding from conductive plastic composite materials. Furthermore, the method of the present invention can provide an article having a particular field of application in the electronics industry, as the article can provide a moldable member that is conductive. The method of the present invention allows polymer materials and composites of conductive fillers such as high aspect ratio fillers to be molded in the most conductively efficient manner while still maintaining low manufacturing costs. . By selecting materials according to the application field in the near future, high thermal and / or electrical conductivity can be achieved. Relatedly, the selection of high strength materials as fillers can achieve molded structural articles with high structural integrity while still being moldable, such as by injection molding.
[0009]
A method of molding a thermally, electrically and / or structurally reinforced article is provided, such as by injection molding. If conductive fillers are used, articles having electrical properties such as conductivity or EMI shielding can be achieved. When a thermally conductive filler material is used, a thermally conductive article is achieved. When high strength fillers such as carbon are used, structurally reinforced articles can be achieved by the method of the present invention. Similarly, fillers that exhibit all electrical, thermal, and strength properties can be selected to provide a multipurpose molded article.
[0010]
First, a mold assembly is provided that can form an article of a desired configuration. Next, for thermal applications using thermally conductive fillers, the initial contact position of the article with the heat generating surface is determined. An entrance gate is formed in the mold assembly at an initial contact location. An optimal heat flow path through the article is determined. The end position of the thermal or electrical flow path is determined. A polymer doped with an asymmetric conductive filler is introduced into the mold assembly through an inlet gate. A vent is provided in the mold assembly at the end of the thermal or electrical flow path. The polymer is placed in the mold assembly with the conductive filler substantially parallel to the flow path and aligned with the flow path. Finally, the molded article is ejected from the mold assembly. With the molding method of the present invention, the thermal conductivity of the article can be increased several times that achieved by conventional molding methods by appropriately aligning the filler material within the article body to be molded. When using conductive or high strength fillers, the methods described above are used. With respect to the electrical filler, the desired electrical flow path through the article is determined and the appropriate inlet and outlet gates are selected to ensure that the filler is aligned along the determined electrical flow path. Set to maintain route. Similarly, structural fillers can be used, high stress points are determined, and gates and vents are set to ensure proper alignment of the reinforced filler to prevent breakage.
[0011]
Accordingly, it is an object of the present invention to provide a method for forming a thermally optimized reinforced article.
Accordingly, it is an object of the present invention to provide an electrically optimized method for forming a reinforced article.
Accordingly, it is an object of the present invention to provide a method of forming a reinforced article that is structurally optimized.
[0012]
It is an object of the present invention to provide a method of forming a reinforced article with a polymer and an asymmetric high aspect ratio filler material that places and aligns the filler for optimal heat transfer through the article.
It is an object of the present invention to provide a method of forming a reinforced article of a polymer and an asymmetric high aspect ratio filler material that places and aligns the filler for optimal electrical transfer through the article.
It is an object of the present invention to provide a method of forming a reinforced article of a polymer and an asymmetric high aspect ratio filler material that places and aligns the filler for optimal structural strength of the article.
[0013]
It is a further object of the present invention to provide a method for forming a conductive article that achieves a higher conductivity than conventional methods while using the same polymer and filler composition.
It is a further object of the present invention to provide a method for molding conductive articles that achieves higher strength and structural integrity than conventional methods while using the same polymer and filler composition.
[0014]
It is another object of the present invention to provide a method of forming a reinforced composite article having a high aspect ratio filler into a complex part geometry.
The novel features that are characteristic of the invention are set forth in the appended claims. However, along with further objects and attendant advantages, preferred embodiments of the present invention will be best understood by reference to the following detailed description, taken in conjunction with the accompanying drawings, in which:
[0015]
Detailed Description of Preferred Embodiments
The present invention relates to a method of forming a reinforced composition. It should be understood that the present invention can be used to form articles that are both thermally and electrically conductive and / or structurally reinforced. The type of thermal, electrical, or structural reinforcement realized by the method of the present invention is achieved by the selection of a specific material to suit a given application field and reinforcement requirements.
[0016]
In the present invention, a method for forming a reinforced article, such as by injection molding, uses a base polymer matrix composite material filled with a filler material, which is preferably an elongated fiber, strand, rice or flake. High aspect ratio fillers such as aluminum, alumina, copper, magnesium, PITCH-based carbon, and brass materials formed in any of the above. The aforementioned materials achieve thermal or electrical properties for net-shaped molded articles that are ready to use after molding without the need for further machining, such as that required for compression molded articles. Therefore, it will be suitable. As shown in FIG. 1, a prior art composite 2 that is readily commercially available is shown. In particular, this prior art composite 2 generally exhibits a polymer base matrix 4 filled, for example, with an asymmetric filler material 8. This composition is shown in expanded detail for clarity and ease of illustration.
[0017]
As will be appreciated, the filling of the polymer base matrix 4 with filler 8 that is thermally conductive, conductive, or capable of strengthening the structure imparts conductivity to the material, while Can be molded. When used as a thermal conductor, the material 2 must thermally transfer heat, for example from the X side to the Y side of the material. During this transfer, heat must move from the thermally conductive filler member to the adjacent thermally conductive filler member in order to travel the path from X to Y. The selected filler 8 in FIG. 1 is preferably a high aspect ratio fiber or strand to reduce the number of interfaces between several filler members, as well as the non-conductive polymer present between them. is there. The more the interface that heat must traverse, and the more polymer that heat must pass through, the lower the thermal conductivity. Furthermore, overfilling with filler material can prevent wetting of the base polymer, resulting in undesirable small air pockets in the finished molded product.
[0018]
The ideal arrangement of the composition of FIG. 1 includes a high aspect ratio filler 4 within a polymer base matrix 4. In order to effectively reduce the total number of interfaces through which heat must travel and the volume of the base polymer, it is important to align the high aspect ratio filler as parallel as possible with the heat flow path. FIG. 1 shows a practical filler 8 arrangement with a base polymer matrix, the fillers 8 being generally aligned parallel to each other and in a general desired heat flow direction from the X side to the Y side. Aligned. However, as can be seen in FIG. 1, the transverse flow path from the A side to the B side is due to the increased number of thermal interfaces and the increased volume of non-conducting polymer to which heat must travel. Very undesirable. Therefore, it is important that the filler 8 is properly aligned with the thermally conductive article, i.e. aligned parallel to the heat flow path. In general applications, the thermal conductivity of path XY can be eight times the thermal conductivity of paths AB across the filler alignment. For example, the thermal conductivity of path AB can be 2 W / mK, while the thermal conductivity of path XY exceeds 16 W / mK. Similar problems arise when attempting to make the composition as electrically conductive or structurally reinforced as possible.
[0019]
The goal of aligning reinforcing fillers aligned and parallel to thermal or electrical flow, or structural stress lines, is often difficult to achieve due to the geometric complexity of the parts being molded. As previously described, one of the main reasons for using conductive plastic compositions is that they can be molded into more complex geometries to achieve better heat dissipation and electrical flow. is there. Thus, when forming a conductive polymer material, it is generally an intricate part geometry. The forming method of the present invention solves the problem of forming complex geometries with materials having fillers that need to be aligned to thermal or electrical flow paths or structural stress lines.
[0020]
With these intricate geometries, turbulence of the filler-filled matrix generally results in filler material impingement and non-uniform alignment. Highly ordered fillers aligned in parallel are clearly preferred, but cannot be achieved. Furthermore, flow disturbances and collisions with the mold edges often break high fillers, particularly when they have an aspect ratio greater than 20: 1. FIG. 1 shows a practical composition 2 having fillers 8 substantially aligned with adjacent fillers 8 in polymer 4. FIG. 1 is encountered in the art because of the inherent problems associated with molding materials having fillers. As will be discussed in detail below, the method of the present invention allows the formation of complex geometries that reduce fracture of the high aspect ratio filler 8 that would reduce the desired reinforcement of the composition.
[0021]
Referring first to FIGS. 2A and 2B, an article molded using a prior art molding process is shown. For example, FIG. 2A shows a perspective view of a known thermally conductive article 10. In particular, the thermally conductive article 10 is shown as a heat sink having a base 12 and upstanding fins 14 connected thereto. The heat sink 10 is typically attached to a heat generating surface of a device (not shown) such as a semiconductor package for the purpose of removing heat from the high temperature device. This heat dissipation is particularly important in the field of electronic applications to ensure that the device does not fail due to overheating.
[0022]
The bottom surface 20 of the base 12 is disposed on the same surface that is in thermal communication with the semiconductor device to be cooled. In general, the semiconductor device to be cooled is placed directly under the center of the base 12, generally referred to by reference numeral 22, and achieves 360 degrees of thermal diffusion around the device to be cooled. As shown in FIG. 2B, which is a bottom view of the molded article 10, the semiconductor device 22 that generates heat is disposed in a substantially central region of the base 12. As a result, heat is dissipated outward from the central region 22 where the heat generating semiconductor device is disposed.
[0023]
Similarly, FIGS. 2A and 2B show the general flow pattern of the molding material as it is introduced into the mold. Molding material is generally introduced into an inlet gate 16 at one end of the article for flow from left to right and upward into the fins 14. There is a vent 18 at the top of each fin, typically on a discharge pin (not shown), to release air in the mold cavity. Base polymers with high aspect ratio fillers to form conductive polymers are not common for forming heat sinks with complex geometries. Thus, in the past, the flow direction of a molding material that does not have a filler in the molding material is of little importance if not all. Now, with high aspect ratio fillers, the gate pattern and flow pattern in the mold cavity are very important when processed in the method of the present invention.
[0024]
The articles of FIGS. 2A and 2B are molded with a flow pattern of molding material, with an inlet gate location indicated at 16, so the filler material orientation alignment is essentially shown in a left-to-right arrangement. Parallel to the arrow. However, the horizontal placement and alignment of the filler material 8 significantly degrades the thermal conductivity of the article 10.
[0025]
When a semiconductor device that generates heat is arranged in the central region 22, the heat naturally tends to radiate outward in all directions. As best seen in FIG. 2B, the thermal conductivity of the article 10 when moving to the left or right is generally acceptable because the heat flow path is parallel to the alignment of the filler material 8. However, when moving up or down, the heat flow path crosses the alignment of the filler 8 in the polymer 4 and therefore heat must cross the further interface. As a result, the thermal conductivity in these directions is significantly degraded. Since heat transfer is a bulk property, the overall thermal conductivity of the article 10 is not optimal to fully utilize the conductivity properties of the filler material 8 filled in the polymer base matrix 4 and is completely It cannot be used. When fillers that are conductively or structurally reinforced are used, similar degradation of the effect of the reinforced filler occurs.
[0026]
Referring to FIGS. 3A, 3B, 4, and 5, the molding method of the present invention is shown in detail. Referring now to FIGS. 3A and 3B, the article 100 includes a base 112 and upstanding fins 114 connected to the base 112. By way of example, the present invention will be described with respect to forming a thermally conductive article. Molding of conductive or structurally reinforced articles is performed using the same method. The bottom surface 120 of the base 112 is provided on the same surface that is in thermal communication with a semiconductor device (not shown) that generates heat. Referring to both FIGS. 3A and 3B, which show bottom views of the article 100, the semiconductor device is positioned substantially below the center of the article 100 in the region identified as 122. FIG. In accordance with the present invention, an inlet mold gate is centrally provided at 16 for introducing molding material into a mold cavity (not shown). In addition, a vent is provided in 118, where, for example, after being molded, a discharge pin (see figure) is provided to simultaneously achieve the release of air and to help eject the article 100 from the mold. (Not shown) and a space around the discharge pin.
[0027]
In accordance with the present invention, the introduction of molding material at the centrally located gate 116 allows the molding composite material to flow outwardly and upwardly to the fins 114 in a pattern emanating from the gate 116. This flow radiation pattern aligns high aspect ratio fillers 8 filled in the polymer base matrix 4 with them. As a result, the filler 8 is oriented in an outward radiating pattern, as shown by the arrows in FIG. 3B, and is in close proximity to the actual thermal radiation path of heat exiting the semiconductor device that generates heat disposed in the central region 122 Matches. According to the present invention, closely matching the radiation pattern of the filler 8 to the actual heat flow path of heat from the central region 122 utilizes fully composite polymer materials, ie, high aspect ratios within them. The high conductive properties of the filler 8 are used.
[0028]
FIG. 4 illustrates a method for forming an electrical ground plate in a manner similar to the heat sink shown above in connection with FIGS. 3A and 3B. In FIG. 4, a substantially flat ground plate 200 is shown with a body 220 having a bottom surface for contacting a power source, such as a neutral ground connection. In accordance with the present invention, the plate 200 is formed by providing an entrance gate at the center, at 216, which is located in the center region 222 and predetermined 216 to be the center of the power source. Along with the inlet gate 216, a vent is provided at the edge 212 of the plate 200 to drive the flow of molding material outward in a radiation pattern that closely matches the actual electrical flow path of electricity from the neutral ground connection. . As described above, the radiant flow outward of the molded composite material naturally aligns the high aspect ratio filler 8 with the electrical flow and thus matches the filler alignment with the flow path.
[0029]
The method of forming a structurally reinforced article according to the present invention is similar to the forming of an article with enhanced thermal and electrical conductivity as described above. The stress line is determined and then verified to determine the desired filler alignment path, which is the desired placement of the structurally reinforcing filler material. The inlet gate is positioned to set the source of filler material in the mold to correspond to the desired location so as to reduce the effects of article stress. An exit gate or vent is similarly provided to further control the path and alignment of the filler within the castable article. For structurally reinforced articles, a suitable filler is carbon fiber.
[0030]
Referring to FIGS. 5A and 5B, a mold assembly, such as an injection mold assembly, is shown for use in the method of the present invention. FIG. 5A shows a bottom half 300 of the mold assembly having a body 306 with a cavity 302 in the mold assembly. A gate 304 is centrally located at the bottom of the cavity 302 to introduce molding material into the mold. Guide pins 308 are similarly provided to be received in corresponding openings 312 of the upper mold half 310 shown in FIG. 5B. The molding apparatus shown in FIGS. 5A and 5B can generally be manufactured by known mold manufacturing techniques. However, as detailed above, the location of the gate 304 is specifically selected by the present invention to fully utilize the properties of the molding material with the reinforcing filler in the molding material.
[0031]
In connection with the present invention, a method of forming an enhanced article for transferring heat and / or electricity from a source is provided. A method of forming a reinforced high structural integrity article is also provided. First, a mold assembly is selected that can form an article of the desired configuration. The contact position of the article with the source surface is determined. In the mold assembly, the inlet gate is formed at a location that is substantially the center of the surface of the article to be molded that contacts the heat or electrical source. The optimal thermal or electrical flow path through the article is then determined through the article to be molded as well as the end location of the flow path. A vent is formed in the mold assembly at the end of the flow path. As part of the molding process, a polymer filled with a conductive high aspect ratio filler is introduced into the mold assembly via a preselected inlet gate. The polymer is placed in the mold assembly with the conductive filler substantially parallel to and aligned with the predetermined heat flow path to fully optimize the conductivity of the polymer / filler composition. Is done. After formation, the molded and completed article is ejected from the mold assembly.
[0032]
(Example)
The forming apparatus shown in FIGS. 5A and 5B is assembled to form the heat spreader shown in FIG. The composite molding material is introduced into the mold through an inlet gate located in the center of the bottom of the mold. The molding material used comprises a base polymer matrix with high aspect ratio filler carbon flakes, the filler carbon flakes having a thickness of 2/1000 to 4/1000 inches and a length of 40/1000 inches, approximately It has a minimum aspect ratio of 10: 1. After molding, the carbon is peeled off at locations aligned with the heat spreader article completed in a radial pattern extending outwardly at the edges of the article. This radiation pattern closely matches the actual flow path of heat through the article in order to fully use the thermal conductivity of the material.
[0033]
As will be appreciated, the present invention can be adapted to form a wide array of configurations and shapes using the method of the present invention. In this regard, the choice of gate location and vent in the mold effectively aligns the desired filler within the article. The method of the present invention achieves higher thermal and electrical conductivity and higher strength articles than is possible with conventional methods, even with the same polymer and filler. Base materials and fillers can be selected to optimize the desired thermal, electrical, and structural properties of the finished article.
[0034]
Those skilled in the art will appreciate that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the invention. All such modifications and changes are intended to be included within the scope of the claims.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a prior art reinforcing composition of a polymer base matrix doped with a high aspect ratio filler.
FIG. 2A is a perspective view of a heat sink using a prior art gate and vent known in the art.
FIG. 2B is a bottom view of the heat sink in FIG. 2A.
FIG. 3A is a perspective view of a heat sink using the gate and vent molding method of the present invention.
FIG. 3B is a bottom view of the heat sink in FIG. 3A.
FIG. 4 is a perspective view of a heat spreader using the gate and vent molding method of the present invention.
FIG. 5A is a perspective view of the bottom half of a molding apparatus using the method of the present invention.
FIG. 5B is a perspective view of the upper half of the molding apparatus using the method of the present invention.

Claims (23)

A method of forming a thermally conductive article in a desired final shape for transferring heat from the surface of a body that generates heat, comprising:
Providing a mold assembly having a mold cavity of a shape corresponding to the desired final shape, the mold assembly corresponding to a position of contact with a surface of the object generating heat in the molded article. An inlet gate at a position, and a vent at a position corresponding to a design heat channel end position starting from the contact position in the molded article, the method further comprising:
Introducing a polymer with a thermally conductive filler added into the mold cavity of the mold assembly through the inlet gate, the polymer being guided through the mold cavity from the inlet gate toward the vent. The thermally conductive filler is disposed radially from the inlet gate to the vent along the designed thermal flow path in the polymer; and
Discharging the molded article from the mold assembly into a desired final shape.   The method of claim 1, wherein the thermally conductive filler is an elongated thermally conductive fiber.   The method of claim 1, wherein the thermally conductive filler is a flaky material.   The method according to claim 1, wherein the thermally conductive filler is a rice-like material.   The method of claim 1, wherein the thermally conductive filler is a carbon material.   The method of claim 1, wherein the thermally conductive filler is an aluminum material.   The method of claim 1, wherein the thermally conductive filler is selected from the group consisting of aluminum, alumina, copper, magnesium, and brass. A method of forming a conductive article for transmitting electricity from a power source in a desired final shape,
Providing a mold assembly having a mold cavity having a shape corresponding to the desired final shape, the mold assembly having an entrance gate at a position corresponding to a position of contact with the power source in the molded article. A vent in a position corresponding to a terminal position of the designed electrical flow path starting from the contact position in the molded article, and the method further includes:
Introducing a polymer doped with a conductive filler into the mold cavity of the mold assembly through the inlet gate, the polymer being guided from the inlet gate toward the vent through the mold cavity; The conductive filler is disposed radially from the inlet gate to the vent along the designed electrical flow path in the polymer; and
Discharging the molded article from the mold assembly into a desired final shape.   The method of claim 8, wherein the conductive filler is an elongated conductive fiber.   The method according to claim 8, wherein the conductive filler is a flaky material.   The method according to claim 8, wherein the conductive filler is a rice-like material.   The method according to claim 8, wherein the conductive filler is a carbon material.   The method according to claim 8, wherein the conductive filler is an aluminum material.   The method of claim 8, wherein the conductive filler is selected from the group consisting of aluminum, alumina, copper, magnesium, and brass. A method of forming a structurally reinforced article into a desired final shape, comprising:
Providing a mold assembly having a mold cavity shaped to correspond to the desired final shape, the mold assembly structurally strengthening the article against design stress points in the molded article An inlet gate at a position corresponding to a starting position of the designed filler alignment path, and a vent at a position corresponding to an end position of the designed filler alignment path, the method further comprising:
Introducing a polymer, to which a reinforcing filler for structurally reinforcing an article is added, into the mold cavity of the mold assembly via the inlet gate, the polymer passing through the mold cavity in the inlet gate; The reinforcing filler is disposed radially from the inlet gate to the vent along the designed filler alignment path in the polymer by being directed toward the vent from
Discharging the molded article from the mold assembly into a desired final shape.   The method of claim 15, wherein the reinforcing filler is an elongated fiber.   The method of claim 15, wherein the reinforcing filler is a flaky material.   The method of claim 15, wherein the reinforcing filler is a rice-like material.   The method of claim 15, wherein the reinforcing filler is a carbon material.   The method of claim 15, wherein the reinforcing filler is an aluminum material.   The method of claim 15, wherein the reinforcing filler is selected from the group consisting of aluminum, alumina, copper, magnesium, carbon, and brass. A method of manufacturing a mold assembly that is used to mold a thermally conductive article for transferring heat from a surface of a body that generates heat in a desired final shape, comprising:
Providing a mold assembly having a mold cavity of a shape corresponding to the desired final shape;
Determining a first position on the mold assembly corresponding to a contact position between the article and the surface of the object generating the heat;
Designing a desired design heat flow path starting from the contact position in the article;
Determining a second position on the mold assembly corresponding to the desired design thermal flow path termination position;
Forming an entrance gate in the mold assembly at the first location;
Forming a vent in the mold assembly at the second location. A method of manufacturing a mold assembly used to form a conductive article for transferring electricity from a power source in a desired final shape, comprising:
Providing a mold assembly having a mold cavity of a shape corresponding to the desired final shape;
Determining a first position on the mold assembly corresponding to a contact position between the article and the power source;
Designing a desired design electrical flow path starting from the contact position in the article;
Determining a second position on the mold assembly that corresponds to an end position of the electrical flow path on the desired design;
Forming an entrance gate in the mold assembly at the first location;
Forming a vent in the mold assembly at the second location.

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