WO2017024444A1

WO2017024444A1 - Coating conductive components

Info

Publication number: WO2017024444A1
Application number: PCT/CN2015/086373
Authority: WO
Inventors: Chienlung YANG; Chi-Hao Chang; Chien-Ting Lin; Kuan-Ting Wu
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2015-08-07
Filing date: 2015-08-07
Publication date: 2017-02-16

Abstract

A method for coating a conductive component is provided. In the method, the conductive component is immersed into a suspension of electrophoretic deposition contained in a container. Then the conductive component is set as an electrode of two electrodes located in the suspension of electrophoretic deposition. Direct current electricity is applied to the two electrodes to form an electric field between the two electrodes and form a coating on the conductive component. Also provided an appratus for coating the conductive component and a conductive component comprising the coating formed by the method.

Description

COATING CONDUCTIVE COMPONENTS

BACKGROUND

An electronic device such as a computer or a liquid-crystal display (LCD) panel may generate a great amount of heat during working. The heat generated may cause the electronic device to be overheated and damaged. For example, there may be a risk of battery explosion when the electronic device is overheated. Thus, heat dissipation is to be considered during the manufacture of the electronic device.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present disclosure, reference should be made to the Detailed Description below, in conjunction with the following drawings in which like reference numerals refer to corresponding parts throughout the figures.

FIG. 1 is a flowchart illustrating a method for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure；

FIG. 2A is a schematic diagram illustrating a conductive component according to an example of the present disclosure；

FIG. 2B is a stereogram illustrating a conductive component according to an example of the present disclosure；

FIG. 3 is a flowchart illustrating a method for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure；

FIG. 4 is a flowchart illustrating a method for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure； and

FIG. 5 is a schematic diagram illustrating an apparatus for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure； and

FIG. 6 is a schematic diagram illustrating an apparatus for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to examples, which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. Also, the figures are illustrations of examples, in which modules or procedures shown in the figures are not necessarily essential for implementing the present disclosure. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the examples.

In an example, a conductive component may be put into an electronic device to dissipate heat. To dissipate heat more efficiently, the conductive component may be coated with a heat radiation layer formed of for example, graphene, carbon nanotube, diamond, graphite, silicon carbide, boron nitride, or synthetic thermal conductive materials using an electrophoretic deposition process. A thickness of the formed heat radiation layer may be 5-40μm.

Fig. 1 is a flowchart illustrating a method for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure. As shown in Fig. 1, the method may include the following procedures.

At block 101, the conductive component may be immersed into a suspension of electrophoretic deposition contained in a container. For example, the conductive component may be immersed by being hooked with a designed fixture or holder according to the shape of conductive component. The fixture or holder may be set inside the container, or may be fixed somewhere outside the container, so as to hook the conductive component and immerse it partly or totally into the suspension of electrophoretic deposition.

The conductive component may be a heat pipe, a heat sink, or an assembly of them. Fig. 2A is a schematic diagram illustrating a conductive component according to an example of the present disclosure.

As shown in Fig. 2A, the conductive component 10 may include a heat pipe 11, a shielding cover 12, and a heat sink 13 which are thermal conductive and may be formed of for example aluminum, copper, stainless steel, or alloys.

The heat pipe 11 may be a curved encapsulated pipe in which a liquid may be encapsulated, and may transfer heat between a hot end 14 and a cool end 15 of it. The hot end 14 may be attached to a heat generating device (not shown) , e.g., a CPU of a laptop computer, by using the shielding cover 12. The cool end 15 may be attached with the heat sink 13.

At the hot end 14 of the heat pipe 11, the liquid in contact with a surface of the heat pipe 11 may turn into a vapor by absorbing heat from that surface. The vapor then may go along the heat pipe to the cool end 15 and condense back into a liquid to release the heat. The liquid then may return to the hot end 14. The cycle repeats to cool the heat generating device.

The shielding cover 12 may be plate-like, and may basically have a cross shape. A first surface 18 of the shielding cover 12 may be flat (See side A in Fig. 2A) , and may be closely attached to a surface of the heat generating device to conduct heat generated by the heat generating device. A second surface 19 of the shielding cover 12 is to fasten the heat pipe 11 (See side B in Fig. 2A) .

For example, on the second surface 19 of the shielding cover 12, a latch part16 may be formed to fasten the heat pipe 11. The latch part may form a space with the second surface 19 so that the hot end 14 of the heat pipe 11 can be inserted through the space along the second surface 19. As shown in Fig. 2A, for example, the latch part 16 may include two parallel bent bars.

There may be a plurality of projecting parts 17 extending horizontally from edges of the shielding cover 12. For example, as shown in Fig. 2A, four projecting parts 17 may extend horizontally from four corners formed by crossed parts of the shielding cover 12. On each of the projecting parts 17, there may be a screw hole formed for fixing the shielding cover 12 on the surface of the heat generating device by using a screw. In this way, the second surface 19 of the shielding cover 12 may be tightly attached to the surface of the heat generating device, to achieve a better heat dissipation effect. On a main body of the shielding cover 12, there may be additional screw holes 21 for fixing the shielding cover 12 to the heat generating device.

The heat sink 13 may have a flat base 22 which has a surface to be attached to a surface of the cool end 15 of the heat pipe 11 (as shown in Fig. 2B) . On the flat base, multiple thermal radiation surfaces 23 may be formed to dissipate heat conducted from the heat pipe 11 into air for example. The larger the area of the thermal radiation surfaces 23 is the more heat is dissipated. The heat sink 13 may be a fin. The heat sink 13 may be welded or bonded to the heat pipe 11.

The suspension of electrophoretic deposition may be formed by blending a solute into a water born charged polymer (e.g., an aqueous charged polymer) . The water born charged polymer may be generated by mixing a polymer with water. A content of the polymer may be no larger than 30％in the water born charged polymer. The polymer may be selected from a group including polyacrylic and epoxy. The solute may be selected from a group including particles of graphene, carbon nanotube, diamond, graphite, silicon carbide, boron nitride, and/or synthetic thermal conductive materials. A size of a particle of graphene, carbon nanotube, diamond, graphite, silicon carbide, boron nitride, or synthetic thermal conductive materials may be 5nm-2μm. As an example, a content of the solute and the polymer may occupy 8-20％in the suspension.

At block 102, the conductive component may be set as one of two electrodes located in the suspension of electrophoretic deposition. For example, the conductive component may be set as a cathode electrode, and there may be multiple anode electrodes. In other examples, the conductive component may be set as an anode electrode.

The blended solute and the water born charged polymer may generate charged polymeric particles. If the charged polymeric particles are anionic, then the conductive component is set as an anode. Or if the charged polymeric particles are cationic, then the conductive component may be set as a cathode. When the conductive component is set as one electrode, the other electrode may be stainless steel, brass, copper, galvanized iron, mild steel, lead, nickel, nickel-chromium, tungsten, tin plate, zinc, phosphor bronze, aluminum, graphite, etc.

At block 103, direct current electricity may be applied to the two electrodes to form an electric field between the two electrodes and form a coating on the conductive component. For example, the direct current electricity may have a voltage of 30-150 volts.

In this block, for example, once the direct current electricity is applied to the two electrodes, the electric field may be formed to drive the anionic charged polymeric particles which contain the solute particles to the conductive component on the cathode side. In this way, an electrophoretic deposition process occurs, and a uniform coating may be formed on the surface of the conductive component. A thickness of the formed coating may be 5-40μm.

Fig. 3 is a flowchart illustrating a method for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure. The method shown in Fig. 3 includes the following procedures.

At block 301, a conductive component is preprocessed to clean the conductive component. The conductive component may have an irregular shape, and may be the conductive component as shown in Fig. 2A and Fig. 2B.

For example, the conductive component may be pre-processed by applied a degreasing process, a chemical polishing process, and a washing process.

For example, the degreasing process may be applied to the conductive component first. During this process, some cleaning solutions such as petroleum, chlorine, or alcohol may be applied to the surface of the conductive component. For example, a degreasing solution may be sprayed on the surface of the conductive component, or the conductive component may be immersed into a degreasing solution.

Then the chemical polishing process may be applied to the conductive component after the degreasing process. The chemical polishing process is to selectively etch a surface of the conductive component with a chemical solvent to smooth the surface of the conductive component.

After the foregoing two processes, a washing process may be applied to remove the chemical solvent and the degreasing solution from the conductive component.

At block 302, the conductive component may be immersed into a suspension of electrophoretic deposition contained in a container.

At block 303, the conductive component is set as an electrode of two electrodes located in the suspension of electrophoretic deposition.

At block 304, direct current electricity may be applied to the two electrodes to form an electric field between the two electrodes and form a uniform coating on the conductive component. For example, the direct current electricity may have a voltage of 30-150 volts.

The detailed processes in blocks 302 to 304 may be similar to those in blocks 101 to 103 and will not be elaborated herein. For detailed information of blocks 302 to 304, please refer to the description for blocks 101 to 103.

Fig. 4 is a flowchart illustrating a method for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure. The method shown in Fig. 4 includes the following procedures.

At block 401, the conductive component may be immersed into a suspension of electrophoretic deposition contained in a container. The conductive component may have an irregular shape, and may be the conductive component as shown in Fig. 2A and Fig. 2B.

At block 402, the conductive component is set as an electrode of two electrodes located in the suspension of electrophoretic deposition.

At block 403, the conductive component may be applied direct current electricity having a voltage of 30-150 volts to the two electrodes to form an electric field between the two electrodes for 20 to 60 seconds and form a uniform coating on the conductive component.

The detailed processes in blocks 401 to 403 may be similar to those in blocks 101 to 103 and will not be elaborated herein. For detailed information of blocks 402 to 403, please refer to the description for blocks 101 to 103.

In the forgoing examples, during the electrophoretic deposition process, the temperature of the suspension of electrophoretic deposition may be kept to be 25-40℃.

With the coating formed according to the examples of the present disclosure, heat radiation or dissipation by the conductive component may be more efficient, the conductive component may be better protected from being eroded by environment, e.g., being oxidized, and a lifetime of the conductive component may be extended. Further, when the conductive component with the coating is applied to dissipate heat generated by the heat generating device, since heat is more efficiently dissipated, the heat generating device may work more efficiently, and a lifetime of the heat generating device may be extended.

Fig. 5 is a schematic diagram of an apparatus for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure. The apparatus is to coat the conductive component via an electrophoretic deposition process. As shown in Fig. 5, the apparatus may include a container 51, a holder 52, and a power supply 53.

The container 51 may contain a suspension of electrophoretic deposition 54 for immersing the conductive component 55 which has an irregular shape.

The holder 52 may set the conductive component 55 as an electrode of two electrodes located in the suspension of electrophoretic deposition 54. For example, the holder 52 may be a clamp that clamps the conductive component 55 at the cathode side. In Fig. 5, the holder 52 is shown with one end being fixed on a side of the container, and the other end hooking the conductive component, so that a part of or all of the conductive component 55 may be immersed into the suspension of electrophoretic deposition 54. However, the holder 52 may be set outside the container as well.

When the conductive component is set as one electrode, the other electrode may be stainless steel, brass, copper, galvanized iron, mild steel, lead, nickel, nickel-chromium, tungsten, tin plate, zinc, phosphor bronze, aluminum, graphite, etc.

The blended solute and the water born charged polymer may generate charged polymeric particles. If the charged polymeric particles are anionic, then the conductive component may be set as an anode. Or if the charged polymeric particles are cationic, then the conductive component may be set as a cathode.

The power supply 53 may apply direct electricity having a voltage of 30-150 volts to the two electrodes to form an electric field between the two electrodes and form a coating on the conductive component 55. The power supply 53 may be applied on the two electrodes for 20 to 60 seconds.

Once the direct current electricity is applied to the two electrodes, the electric field may be formed to drive anionic charged polymeric particles which carry the coating material to the conductive component 55 on the cathode side. Thus, an electrophoretic deposition process occurs, and a coating is formed on the surface of the conductive component 55.

Fig. 6 is a schematic diagram of an apparatus for coating a conductive component using an electrophoretic deposition process according to an example of the present disclosure.

Based on the apparatus drawn in Fig. 5, the apparatus in Fig. 6 may further include a temperature detector 56, and a temperature adjuster 57. The temperature detector 56 may include a thermal sensor. The temperature adjuster 55 may keep a temperature of the suspension of electrophoretic deposition to be 25-40℃. The temperature detector 56 and the temperature adjuster 57 may be set under the container 51.

It should be noted that, in some implementations, the blocks in the flowcharts may be performed out of the order illustrated, depending on the functions of the blocks. For example, two blocks shown in succession may be executed concurrently.

In the figures, the conductive components are drawn for illustration purpose, and should not be construed as limitations to the present disclosure.

What is described in the foregoing are only examples of the present disclosure, and should not be construed as limitations to the present disclosure. Any changes, equivalent replacements, modifications made without departing from the scope and spirit of the present disclosure are intended to be included within the protecting scope of the present disclosure.

Claims

A method for coating a conductive component, comprising:

immersing the conductive component into a suspension of electrophoretic deposition contained in a container；

setting the conductive component as an electrode of two electrodes located in the suspension of electrophoretic deposition； and

applying direct current electricity to the two electrodes to form an electric field between the two electrodes and form a coating on the conductive component.
The method of claim 1, wherein a temperature of the suspension of electrophoretic deposition is kept to be 25-40℃.
The method of claim 1, wherein applying the direct current electricity to the two electrodes comprises:

applying the direct current electricity having a voltage of 30-150 volts to the two electrodes for 20 to 60 seconds.
The method of claim 1, further comprising:

blending particles of a solute into a water born charged polymer to form charged polymeric particles in the suspension of electrophoretic deposition,

wherein the water born charged polymer is formed by mixing a polymer with water； the solute is selected from a group comprising graphene, carbon nanotube, diamond, graphite, silicon carbide, boron nitride, and a synthetic thermal conductive material； the polymer is selected from a group comprising polyacrylic and epoxy； and the electric field drives the charged polymeric particles to the conductive component to form the coating on the conductive component.
The method of claim 4, further comprising:

setting a content of the polymer to be no larger than 30％ in the water born charged polymer； and

setting a content of the polymer and the solute to be 8-20％ in the suspension.
The method of claim 1, wherein the conductive component has an irregular shape comprising:

a heat pipe；

a shielding cover on which a first end of the heat pipe is fastened； and

a heat sink which has a multiple heat radiation surfaces and is mounted on a second end of the heat pipe.
An apparatus for coating a conductive component, comprising:

a container, to contain a suspension of electrophoretic deposition for immersing the conductive component；

a holder, to set the conductive component as an electrode of two electrodes located in the suspension of electrophoretic deposition； and

a power supply, to apply direct current electricity to the two electrodes to form an electric field between the two electrodes and form a coating on the conductive component.
The apparatus of claim 7, wherein the apparatus further comprises:

a temperature adjuster to keep a temperature of the suspension of electrophoretic deposition to be 25-40℃.
The apparatus of claim 7, wherein the power supply is to apply the direct electricity having a voltage of 30-150 volts to the two electrodes for 20 to 60 seconds.
A conductive component, comprising a coating formed by:

immersing the conductive component in a suspension of electrophoretic deposition contained in a container；

setting the conductive component as an electrode of two electrodes located in the suspension of electrophoretic deposition；

applying direct current electricity to the two electrodes to form an electric field between the two electrodes and form a coating on the conductive component.
The conductive component of claim 10, wherein the coating is formed by:

keeping a temperature of the suspension of electrophoretic deposition to be 25-40℃.
The conductive component of claim 10, wherein the coating is formed by:

applying the direct current electricity having a voltage of 30-150 volts to the two electrodes for 20 to 60 seconds.
The conductive component of claim 10, wherein the coating is formed by:

blending particles of a solute into a water born charged polymer to form charged polymeric particles in the suspension of electrophoretic deposition,

wherein the water born charged polymer is formed by mixing a polymer with water； the solute is selected from a group comprising graphene, carbon nanotube, diamond, graphite, silicon carbide, boron nitride, and a synthetic thermal conductive material； the polymer is selected from a group comprising polyacrylic and epoxy； and the electric field drives the charged polymeric particles to the conductive component to form the coating on the conductive component.
The conductive component of claim 13, wherein the coating is formed by:

setting a content of the polymer to be no larger than 30％ in the water born charged polymer； and

setting a content of the polymer and the solute to be 8-20％ in the suspension.
The conductive component of claim 10, wherein the conductive component has an irregular shape comprising:

a heat pipe；

a shielding cover on which a first end of the heat pipe is fastened； and

a heat sink which has multiple heat radiation surfaces and is mounted on a second end of the heat pipe.