KR20240014213A - Integrated Composition Member With EMI Shield And Thermal Transfer And Manufacturing Method Of The Same AND The electronic device - Google Patents

Abstract

The present invention relates to a composite member incorporating a shielding function into a solid TIM for heat dissipation, a manufacturing method thereof, and an electronic device to which the same is applied.
For this purpose, the present invention is characterized by including a heat dissipation member made of solid TIM (Thermal Interface Material, 11) with a metal layer formed on one side, and a shielding member soldered to the metal layer and integrated with the heat dissipation member. In this way, the present invention manufactures a solid TIM and an EMI shielding member for heat dissipation and shielding of electronic devices as one assembly and assembles them integrally on a PCB board, thereby improving the assembly efficiency and greatly improving the shielding effect and heat dissipation effect. there is.

Description

A composite member with integrated shielding and heat dissipation functions and a manufacturing method thereof and an electronic device including the same {Integrated Composition Member With EMI Shield And Thermal Transfer And Manufacturing Method Of The Same AND The electronic device}

The present invention relates to a composite member with integrated shielding and heat dissipation functions, and more specifically, to a composite member with the shielding function integrated into a solid TIM for heat dissipation, a manufacturing method thereof, and an electronic device to which the same is applied.

Recently, electronic devices used in smartphones, smart watches, home appliances, automobiles, and electronic fields are being pursued to be lighter, thinner, more compact, and more functional. As these electronic devices become more highly integrated, more electromagnetic waves and heat are generated. These electromagnetic waves and emitted heat not only deteriorate the function of the device, but also shorten the lifespan of the electronic device or cause breakdown or malfunction. It is becoming important to efficiently shield and dissipate electromagnetic waves and heat generated from .

To this end, thermal interface materials have recently been used as a means to effectively dissipate heat from heating elements in electronic devices. Thermal interface material (hereinafter referred to as ‘TIM’) performs efficient heat transfer by eliminating the air gap between two adjacent members and increasing the contact area. These TIMs are largely used as TIMs in a liquid state with high viscosity or TIMs in a solid state in the form of a pad (PAD).

The present invention relates to a pad-shaped TIM shown in FIG. 1, that is, a solid-state TIM (hereinafter referred to as ‘solid-state TIM’).

Figure 2 is a diagram showing the heat dissipation structure of an AP (Application Processor) with a solid-state TIM applied to a smartphone. About 60% of the heat generated from the AP in a smartphone is transferred to the PCB, and the remaining 40% is transferred to the heat dissipation bracket through the solid TIM. These solid TIMs have recently been increasingly used for heat dissipation design in smartphones.

As such, in recent electronic devices, the demand for heat dissipation members that can effectively dissipate heat generated from heat sources such as semiconductor devices is steadily increasing, and furthermore, complex functionality for electromagnetic wave shielding is required.

Patent Document 1: Korean Patent Publication No. 10-2012762 (Title of invention: Electromagnetic wave shielding and heat dissipation composite sheet and manufacturing method thereof) Patent Document 2: Korean Patent Publication No. 10-1757227 (Title of invention: Composite sheet with integrated electromagnetic wave shielding and heat dissipation functions and manufacturing method thereof) Patent Document 3: Korean Patent Publication No. 10-2018-0083738 (Title of invention: Electromagnetic wave shielding structure with heat dissipation unit and manufacturing method thereof)

The present invention was created in response to recent technical demands requiring complex functionality for heat dissipation and electromagnetic wave shielding as described above, and is a composite member that integrates a conformal shielding member with a solid TIM for heat dissipation into one assembly and its manufacture. The purpose is to provide a method and electronic devices to which it is applied.

The shielding and heat dissipation integrated composite member according to the present invention to solve the above problems includes a heat dissipation member made of solid TIM (Thermal Interface Material) with a metal layer formed on one side; and a shielding member soldered to the metal layer and integrated with the heat dissipation member.

Here, the metal layer is formed integrally with the surface of the solid TIM by plating, and the metal layer may be composed of a first layer made of copper and a second layer made of nickel (Ni).

At this time, the shielding member is composed of a horizontal portion that is horizontal at both ends, and a concave portion sunken to a certain depth is formed in the middle portion of the horizontal portion, and the heat dissipation member is accommodated in the concave portion. It is preferable that the heat dissipation member in the state in which the horizontal portion is accommodated in the concave portion is formed at the same height.

Meanwhile, an electronic device to which the shielding and heat dissipation integrated composite member according to the present invention is applied includes a substrate; Electronic devices mounted on the board; a shield can that surrounds the electronic device, with one end bonded to the substrate to form a sealed surface and the other end to form an open surface; A shielding and heat dissipation integrated composite member that forms an assembly of a shielding member that seals the open side of the shield can to form conformal shielding, and a heat dissipation member made of a solid TIM on which a metal layer to which the shield member is soldered is formed. Includes ;

In addition, the method of manufacturing a shielding and heat dissipation integrated composite member according to the present invention includes preparing a solid TIM; plating a metal layer on one surface of the solid TIM; dispensing solder paste to the metal layer; Mounting a shielding member on the solder paste; and melting the solder paste by induction heating to integrate the shielding member with the solid TIM by soldering.

The composite member with integrated shielding and heat dissipation functions of the present invention configured as described above has the following advantages.

First, there is an advantage that assembly efficiency is greatly improved by manufacturing the solid TIM and EMI shielding member for heat dissipation and shielding of electronic devices as one assembly and assembling them integrally on the PCB board.

Second, by soldering the solid TIM and the EMI shielding member through a metal layer, the fixing force can be strengthened and the thermal conductivity can be improved.

Third, by applying the induction heating method as a soldering heating method, there is no thermal damage to the solid TIM, so heat-resistant materials do not need to be included, thereby reducing the brittleness of the solid TIM and thermal conductivity to maintain compressibility above a certain level and ensure thermal conductivity. The advantage is that there are no restrictions on interfacial material (TIM) design.

Fourth, by using the compressibility of solid TIM, tolerances of heat diffusion members (e.g. Vapor chamber) and fixtures and soldering tolerances of electronic devices (e.g. AP) can be absorbed, which has the advantage of improving assembly precision.

Fifth, the integrated solid TIM and EMI shielding member are seated on the shield can mounted on the PCB board to implement conformal shielding for electronic devices, which has the advantage of greatly improving shielding performance.

Sixth, the solid TIM can transfer heat while contained in a closed space created by the heat diffusion member and the EMI shielding member, which has the advantage of greatly improving heat transfer efficiency.

Figure 1 is a photograph taken of a state in which a conventional solid-state TIM is attached on an electronic device.
Figure 2 is a diagram showing the heat dissipation structure of an AP to which a solid-state TIM is applied in a conventional smartphone.
Figure 3 is a diagram showing a composite member with integrated heat dissipation and shielding functions according to an embodiment of the present invention.
Figure 4 is a diagram showing a structure in which a metal layer is formed on a solid TIM according to an embodiment of the present invention.
Figure 5 is a diagram showing the heat dissipation structure of an electronic device (eg, AP) to which a composite member with integrated heat dissipation and shielding functions according to an embodiment of the present invention is applied.
Figure 6 is a flowchart showing a method of manufacturing a composite member with integrated heat dissipation and shielding functions according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating how an EMI shielding member is assembled into a solid TIM by induction heating soldering according to an embodiment of the present invention.

The present invention integrates an EMI shielding member into a single assembly by soldering a solid thermal interface material (hereinafter referred to as 'solid TIM') to transfer heat generated inside an electronic device.

The present invention can be applied to various electronic devices and can have various embodiments that can be modified, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Hereinafter, the shielding and heat dissipation integrated composite member according to the present invention and the electronic device to which it is applied will be described in detail with reference to the drawings.

Figure 3 is a diagram showing a heat dissipation and shielding integrated composite member according to an embodiment of the present invention, and Figure 4 is a diagram showing a structure in which a metal layer is formed on a solid TIM according to an embodiment of the present invention.

As shown in Figures 3 and 4, in the present invention, the heat dissipation member 10 and the shielding member 20 are manufactured as one assembly (A).

The heat dissipation member 10 is disposed between a heating element such as an electronic device (eg, AP) and a heat sink to increase heat dissipation efficiency, and serves to quickly transfer heat generated from the heating element to the heat sink. This heat dissipation member 10 is made of a solid thermal interface material (TIM) 11 and a metal layer 12.

The solid TIM 11 is in the form of a thin pad (PAD) and is made of a material containing an insulating inorganic material, a thermally conductive filler including carbon nanotubes and a metal material, and a polymer binder.

The metal layer 12 is formed on the surface of the solid TIM 11 and serves as a medium for soldering the shielding member 20. This metal layer 12 has a very thin thickness and includes first and second layers 12a and 12b made of different metals.

At this time, the first layer 12a has a thickness of approximately 30 to 70 um and is disposed in the direction in contact with the solid TIM 11, and the second layer 12b has a thickness of approximately 1 to 3 um and is disposed in the soldering direction. It is placed.

The first layer 12a of the metal layer 12 is made of copper (Cu) for organic heat conduction between the solid TIM 11 and the shielding member 20, and the second layer 12b is a copper (Cu) layer. Tin (Sn) or nickel (Ni) is applied to prevent oxidation and soldering performance. At this time, tin (Sn) is relatively expensive and has a high risk of discoloration, while nickel (Ni) has excellent environmental resistance but has poor soldering performance.

Considering the above, when applying the reflow soldering method in one embodiment of the present invention, it is preferable to use tin (Sn) as the second layer 12b. On the other hand, when applying the induction heating soldering method, since nickel (Ni) has excellent solderability, instead of tin (Sn), nickel (Ni), which is cheaper and has excellent environmental resistance, is used as the second layer (12b). ) has the advantage of being able to use it.

Meanwhile, the present invention proposes the following three methods for bonding the metal layer 12 to the solid TIM 11.

First, method 1 involves applying a liquid silicone mixture onto a metal sheet with a thin film thickness and then curing it. Here, the liquid silicon mixture refers to liquid silicon mixed with a thermally conductive interfacial material (TIM). Method 1 has the advantage of not using adhesive, but has the disadvantage that foreign substances may enter during the joining process and it is difficult to secure a uniform surface (smoothness).

Next, Method 2 is to bond a solid TIM and a metal sheet with a thin film thickness using a thermally conductive adhesive. Method 2 may have the advantage of obtaining a uniform surface compared to Method 1, but it requires a separate adhesive and has the disadvantage that the adhesive may melt, especially at reflow soldering temperature (approximately 240 degrees).

Finally, Method 3 involves direct metallization of the solid TIM surface. In other words, the metal layer is manufactured integrally through dry or wet plating on the surface of the solid TIM sheet. Method 3 has the advantage of having excellent adhesion between the solid TIM and the metal layer because the metal layer is integrated into the solid TIM, efficient heat conduction, and thin film management is easy.

In summary, in the present invention, all three methods described above can be applied in terms of joining the solid TIM 11 and the metal layer 12, but there is no limitation on the soldering method for mounting the shielding member 20 and the solid TIM ( Method 3 (plating method), which has the best bonding strength and heat conduction performance between 11) and the metal layer 12, can be said to be the most preferable embodiment. At this time, the heat dissipation member 10 consisting of the solid TIM 11 and the metal layer 12 is not manufactured individually, but can be manufactured as a whole in a large area and then cut separately to the required size for use.

The shielding member 20 is a member that shields electromagnetic waves generated from the electronic device 30 and is manufactured integrally with the heat dissipation member 10 by soldering. More specifically, the shielding member 20 is soldered to the second layer 12b forming the metal layer 12 in the solid TIM 11 to form one assembly A with the heat dissipation member 10. do.

As shown in FIG. 5, the shielding member 20 of the present invention forms conformal shielding that seals and shields the electronic device 30 to be protected from electromagnetic interference. To this end, the shielding member 20 forms a closed space together with the shield can 60, and the electronic device 30 is disposed within the closed space. At this time, the shielding member 20 is in contact with the electronic device 30 and transfers heat generated from the electronic device 30 to the solid TIM 11.

For this purpose, the shielding member 20 is composed of a horizontal portion 21 at both ends of which are horizontal, and a concave portion 22 protruding at a certain depth in the direction of arrangement of the electronic device 30 is formed in the middle portion. At this time, the concave portion 22 is soldered and joined to a structure in which the solid TIM 11 is accommodated. The height of the concave portion 22 is preferably the same as the height of the solid TIM 11. That is, it is desirable that the exposed surfaces of the solid TIM 11 exposed from the horizontal portion 21 and the concave portion 22 have the same height. For this reason, as shown in FIG. 5, the shielding member 20 and the heat dissipation member 10 can be integrated and joined together to the heat diffusion member 40, which will be described later, with a bonding surface having the same height. In addition, the heat dissipation member 10 has an advantage in that it can more effectively transfer heat from the electronic device by being connected to the heat diffusion member 40 in a sealed structure by the concave portion 22 of the shielding member 20.

This shielding member 20 is preferably made of a metal material such as aluminum (Al) or copper (Cu). However, the material of the shielding member 20 of the present invention is not limited to this, and any material that can be soldered while blocking interference of electromagnetic waves can be applied.

As a soldering method for integrating the shielding member 20 with the surface of the solid TIM 10, the previously mentioned reflow soldering method and induction heating soldering method may be considered.

However, when mounted using the reflow soldering method, the solid TIM 11 must withstand high temperatures and therefore must contain fillers with high heat resistance. If a filler with high heat resistance is included in the solid TIM (11), the heat conduction performance of the solid TIM may decrease, brittleness may increase, and it may be easily damaged. In addition, the hardness of the solid TIM 11 increases due to the inclusion of fillers to enhance heat resistance, so the compression ratio may be relatively low.

Therefore, the present invention suggests that soldering the solid TIM using an induction heating method is a more preferable method than a reflow soldering method. Induction heating soldering heats only the conductor located inside the magnetic field formed by the induction heating coil, so there is no thermal damage to the solid TIM, so there is no need to consider the use of a filler with strong heat resistance. As a result, the heat conduction performance of solid TIM can be improved, brittleness can be reduced, damage to thin solid TIM can be reduced, and normal compression ratio can be maintained. A more detailed description of the structure of solid-phase TIM soldering of the shielding member by the induction heating method will be described later.

Figure 5 is a diagram showing the heat dissipation structure of an electronic device (eg, AP) to which a composite member with integrated heat dissipation and shielding functions according to an embodiment of the present invention is applied.

Referring to FIG. 5, according to various implementations of electronic devices to which the heat dissipation and shielding function composite member (A) of the present invention is applied, an electronic device (e.g., AP, 30) is installed on one side (e.g., bottom) of the PCB board 50. ) is placed, and shield cans 60 may be placed at both ends of the PCB board 50. The shield can 60 is arranged to surround at least a portion of the electronic device 30 and can shield electromagnetic waves generated from the electronic device 30. This shield can 60 may include an opening in which at least a portion of the lower part is open.

At this time, a heat dissipation member 10 and an EMI shielding member 20 made of solid TIM are disposed in the opening of the shield can 60 in the form of an assembly.

Here, the shielding member 20, together with the shield can 60, seals all four sides of the electronic device 30, thereby completely blocking electromagnetic waves generated from the electronic device 30 from the outside. To elaborate further, the shielding member 20 is disposed at the lower part of the shield can 60 in a structure that closes the entire opening of the shield can 60, and has a shape that protrudes toward the electronic device around the opening of the shield can 60. It is installed in contact with the electronic device 30. At this time, thermal conductive grease 70 may be applied between the shielding member 20 and the electronic device 30. In this way, the shielding member 20 can form a conformal shielding structure.

Meanwhile, the solid TIM 11 is disposed outside the closed space created by the shielding member 20 and the shield can 60. To elaborate further, the solid TIM 11 is disposed on one side (concave portion, 22) of the shielding member in the opposite direction where the electronic device 30 is disposed. At this time, the thickness of the solid TIM 11 has the same height as the concave portion 22 of the shielding member 20. The other side of the solid TIM (11) is in contact with the heat diffusion member (40). As a result, the heat of the electronic device 30 transmitted through the solid TIM 11 can diffuse and be emitted to the heat diffusion member 40. The heat diffusion member 40 may include a heat pipe or a vapor chamber. In addition, the unexplained symbol ‘80’ is disposed on the outside of the heat diffusion member 40 and may be a case that forms the exterior of the electronic device or a separate heat sink.

Figure 6 is a flowchart showing a method of manufacturing a heat dissipation and shielding integrated composite member according to an embodiment of the present invention.

Hereinafter, a method of manufacturing a composite member with integrated heat dissipation and shielding functions according to an embodiment of the present invention will be described with reference to FIG. 6.

First, prepare a solid TIM with a metal layer formed on one side (S10). At this time, the metal layer consists of a first layer 12a plated with copper (Cu) and a second layer 12b plated with tin (Sn) or nickel (Ni) (S20).

Next, the shielding member is soldered on the metal layer using an induction heating method to integrally combine the shielding member with the solid TIM. To this end, solder paste is dispensed onto the second layer of the metal layer (S30). Then, the shielding member is mounted on the solder paste (S40). Thereafter, the induction heating unit is placed on the shielding member to inductively heat the soldering surface (S50 and FIG. 7), thereby melting the solder paste, thereby directly mounting the shielding member on the solid TIM (S60).

Meanwhile, as shown in FIG. 7, the induction heating unit 100 includes an induction heating coil 110 electrically connected to a high-frequency power supply unit (not shown), and a magnetic flux induced by the induction heating coil 110. It consists of a magnetic core 120 to focus the soldering area. Accordingly, the magnetic flux concentrated in the magnetic core 120 is transmitted to the soldering target area, so that more effective soldering can be performed.

As described above, in the present invention, the solid TIM for heat dissipation and shielding and the EMI shielding member are integrally combined and assembled on the PCB board by induction heating soldering, thereby improving the fixing force and assembly properties, and also adding heat-resistant filler to the solid TIM. By minimizing mixing and maintaining a compression ratio above a certain level, tolerances of other structures and soldering tolerances of electronic devices can be absorbed, allowing for more flexible response to the assembly of electronic devices.

Although an embodiment of the present invention has been described above with reference to the drawings, those skilled in the art will understand the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that it can be modified and changed in various ways.

10: Heat dissipation member 11: Solid TIM
12: metal layer 12a: first layer
12b: second layer 20: shielding member
30: Electronic device 40: Heat diffusion member
50: PCB board 60: Shield can
70: Thermal conductive grease 100: Induction heating unit
110: induction heating coil 120: magnetic core

Claims (11)

A heat dissipation member (10) made of solid TIM (Thermal Interface Material, 11) with a metal layer (12) formed on one side; and
A shielding member (20) soldered to the metal layer (12) and integrated with the heat dissipation member (10). A composite member with shielding and heat dissipation functions integrated therein. In claim 1,
The metal layer (12) is a composite member with integrated shielding and heat dissipation functions, characterized in that the metal layer (12) is formed integrally with the surface of the solid TIM (11) by plating. In claim 1,
The metal layer 12 is a composite member with integrated shielding and heat dissipation functions, characterized in that the first layer 12a is made of copper (Cu) and the second layer 12b is made of nickel (Ni). In claim 1,
The shielding member 20 consists of a horizontal portion 21 that is horizontal at both ends, and a concave portion 22 recessed to a certain depth is formed in the middle portion of the horizontal portion 21, and the heat dissipation member ( 10) is a composite member with integrated shielding and heat dissipation functions, characterized in that it is accommodated in the concave portion (22). In claim 4,
A composite member with integrated shielding and heat dissipation functions, characterized in that the heat dissipation member (10) forms the same height when the horizontal portion (21) is accommodated in the concave portion (22). substrate 50;
An electronic device 30 mounted on the substrate 50;
A shield can 60 that surrounds the electronic device 30 and has one end bonded to the substrate 50 to form a sealed surface and the other end to form an open surface;
It consists of a shielding member 20 that seals the open surface of the shield can 60 to form conformal shielding, and a solid TIM (Thermal Interface Material) on which a metal layer 12 to which the shielding member 20 is soldered is formed. An electronic device comprising a shielding and heat dissipation integrated composite member (A) forming an assembly in which heat dissipation members are integrated. In claim 6,
An electronic device, characterized in that the metal layer (12) is formed integrally with the surface of the solid TIM (11) by plating. In claim 7,
The metal layer 12 is an electronic device characterized in that it consists of a first layer 12a made of copper (Cu) and a second layer 12b made of nickel (Ni). In claim 6,
The shielding member 20 has a horizontal portion 21 joined to the open end of the shield can 60 while both ends are horizontal, and the middle portion of the horizontal portion 21 is recessed to a certain depth. It consists of a concave portion 22 in contact with the electronic device side,
The heat dissipation member (10) is disposed to be accommodated in the concave portion (22), and the horizontal portion (21) and the heat dissipation member (10) are disposed at the same height. Preparing a solid thermal interface material (TIM);
plating a metal layer on one surface of the solid TIM;
dispensing solder paste on the metal layer;
Mounting a shielding member on the solder paste; and
A method of manufacturing a composite member with integrated shielding and heat dissipation functions, including the step of melting the solder paste by induction heating, wherein the shielding member is integrated into the solid TIM by soldering. In claim 10,
The metal layer consists of a first layer made of copper (Cu) and a second layer made of nickel (Ni), and the shielding member is soldered to the second layer. Manufacturing method.

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