Electromagnetic shielding structure of solid state drive

Disclosed is an electromagnetic shielding structure of a solid state driver (SSD), and particularly an electromagnetic shielding structure of an SSD, in which an electromagnetic shielding structure of a closed shield can type is achieved based on an electromagnetic shielding structure that employs an electromagnetic shielding coating layer electrically connected to a ground via hole formed in a printed circuit board (PCB) and a lower electromagnetic shielding layer formed inside the PCB and electrically connected to the electromagnetic shielding coating layer through the ground via hole, thereby improving electromagnetic shielding performance.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2018-0056064, filed on May 16, 2018 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The disclosure relates to an electromagnetic shielding structure of a solid state drive (SSD), and more particularly to an electromagnetic shielding structure of an SSD, in which an electromagnetic shielding structure of a closed shield can type is achieved based on an electromagnetic shielding structure that employs an electromagnetic shielding coating layer electrically connected to a ground via hole formed in a printed circuit board (PCB) and a lower electromagnetic shielding layer formed inside the PCB and electrically connected to the electromagnetic shielding coating layer through the ground via hole, thereby improving electromagnetic shielding performance.

(b) Description of the Related Art

A conventional general solid state drive (SSD) includes a flash memory; a controller for controlling the flash memory, power components to control a variety of power for the SSD; passive elements such as a resistor, a capacitor, a coil, etc. to stabilize each power of the controller and the flash memory and a logic function; a printed circuit board (PCB) onto which various components such as the flash memory for storing data is mounted; and a connector for power connection and data connection of the SSD.

The electromagnetic shielding structure for the SSD, proposed in Korean Patent Publication No. 10-2018-0000668, refers to an electromagnetic shielding structure for the top and lateral portions of the PCB. However, impact of electromagnetic waves on the bottom portion of the PCB is not negligible, and it is advantageous to avoid impact of external interference from the bottom portion in terms of maintaining performance. Therefore, the electromagnetic shielding structure is needed for not only the top and lateral portions of the PCB but also the bottom portion in order to achieve a completely closed electromagnetic shielding structure. In other words, a conventional shielding structure for the SSD cannot attain a complete electromagnetic shielding structure of a closed shield can type, and thus it is impossible to guarantee the performance and efficiency of the electromagnetic shielding structure.

SUMMARY OF THE INVENTION

Accordingly, the disclosure is conceived to solve the foregoing problems, and an aspect of the disclosure is to provide an electromagnetic shielding structure of a solid state drive (SSD), in which an electromagnetic shielding structure of a closed shield can type is achieved based on an electromagnetic shielding structure that employs an electromagnetic shielding coating layer electrically connected to a ground via hole formed in a printed circuit board (PCB) and a lower electromagnetic shielding layer formed inside the PCB and electrically connected to the electromagnetic shielding coating layer through the ground via hole, thereby improving electromagnetic shielding performance.

In accordance with an embodiment of the disclosure, there is provided an electromagnetic shielding structure of a solid state drive (SSD) including a printed circuit board (PCB), a plurality of memories mounted to the PCB, a controller, and a plurality of active and passive elements, the electromagnetic shielding structure including: a molding resin layer formed on the PCB and covering and surrounding the plurality of memories, the controller, and the plurality of active and passive elements; an electromagnetic shielding coating layer coated on a surface of the molding resin layer and electrically connected to a ground via hole continuously formed along an edge portion of the PCB; and a lower electromagnetic shielding layer formed inside the PCB and electrically connected to the electromagnetic shielding coating layer through the ground via hole.

DETAILED DESCRIPTION

Below, embodiments of an electromagnetic shielding structure of a solid state drive (SSD) according to the disclosure with the foregoing objects, solutions, and effects will be described in detail with reference to the accompanying drawings.

Referring toFIGS. 1 to 5, a key point of an SSD100according to an embodiment of the disclosure is to include an electromagnetic shielding structure proposed according to the disclosure, and specifically include an electromagnetic shielding structure40of a closed shield can type.

In more detail, the SSD100according to an embodiment of the disclosure the SSD100is characterized in including the electromagnetic shielding structure40of the closed shield can type shown inFIG. 1. To this end, an electromagnetic shielding coating layer70coated on a molding resin layer50and a lower electromagnetic shielding layer80formed inside a printed circuit board (PCB)10are electrically connected through a ground via hole11formed along an edge portion of the PCB10, thereby forming a closed shielding structure.

As shown inFIGS. 1 to 3, the SSD100with the electromagnetic shielding structure40of the closed shield can type according to an embodiment of the disclosure includes the PCB10onto which various circuit elements30,31,32,33,35are mounted; and various circuit elements, i.e. a plurality of memories30, a controller33, and a plurality of active and passive elements35, to be mounted onto the PCB10.

The PCB10of the SSD100is mounted with a plurality of memories30such as a flash memory31, a double data rate (DDR) memory32, etc.; the controller33; and the plurality of active and passive elements35. For example, the plurality of memories30including a plurality of stacked flash memories31and the DDR memory32are mounted to one side on the top surface of the PCB10, and the controller33and the passive elements35are mounted to the other side on the top surface. Of course, the passive elements35may be mounted to one side on the top surface.

The SSD100according to the disclosure employs technical features for forming the electromagnetic shielding structure40of the closed shield can type. Specifically, the disclosure includes the molding resin layer50formed on the PCB10to hold and protect circuit elements, the electromagnetic shielding coating layer70coated on the surface of the molding resin layer50and shielding the top and lateral portions of the PCB10against electromagnetic waves, and the lower electromagnetic shielding layer80arranged to be electrically connected to the electromagnetic shielding coating layer70inside the PCB10and shielding the bottom of the PCB10against electromagnetic waves, and connects them to achieve the electromagnetic shielding structure40of the closed shield can type.

The molding resin layer50is made of a nonconductive material, and formed on the PCB10to cover and surround the plurality of memories30including the flash memories31and the DDR memory32, the controller33, and the plurality of active and passive elements35.

The electromagnetic shielding coating layer70is coated on the surface of the molding resin layer50, and electrically connected to the ground via hole11continuously formed along an edge portion of the PCB10. Specifically, the electromagnetic shielding coating layer70may be electrically connected to a plurality of ground via holes11formed on the PCB10, but particularly necessarily formed to be electrically connected to the ground via hole11formed along the edge portion of the PCB10.

It is natural that the ground via hole11to be electrically connected to the electromagnetic shielding coating layer70is filled with a conductive material. Further, the ground via hole11may be connected to a ground line formed inside the PCB10, and electrified connecting with a ground pad12formed on the bottom of the PCB10. Eventually, the electromagnetic shielding coating layer70is connected to the ground pad12through the ground via hole11filled with the conductive material and maintains a ground state, thereby performing an electromagnetic shielding function.

Meanwhile, the plurality of memories30including the flash memories31and the DDR memory32, the controller33, and the plurality of active and passive elements35electrically connect and interface with each other by a circuit signal line and interface line formed inside the PCB10as they are mounted onto the PCB10as described above.

Further, the PCB10may be internally formed with the ground via holes11and additionally formed with the ground line for connecting the ground via holes11with each other. On the bottom of the PCB, the ground pad12is formed to be electrified connecting with the ground via hole11. The electromagnetic shielding coating layer70, the ground via hole11and the ground line are electrically connected through the ground pad12, thereby forming a shielding ground line.

The ground via hole11formed vertically penetrating the PCB10may be formed at various positions as long as it can electrically connect with the electromagnetic shielding coating layer70. However, the ground via hole11may include the ground via hole11formed continuously along the edge portion of the PCB10as shown inFIGS. 2 and 3.

The ground via hole11in the electromagnetic shielding structure40of the closed shield can type is formed in the edge portion of the PCB10, and the molding resin layer50is formed in only an inner portion except the edge portion of the PCB10where the ground via hole11is formed in the electromagnetic shielding structure40of the closed shield can type.

Eventually, the ground via hole11in the electromagnetic shielding structure40of the closed shield can type formed in the edge portion of the PCB10is not covered with the molding resin layer50but exposed to the outside. In this state, the electromagnetic shielding coating layer70is coated on the surface of the molding resin layer50, and subsequently the electromagnetic shielding coating layer70is electrically connected to the ground via hole11.

According to the disclosure, the electromagnetic shielding coating layer70includes a basic electromagnetic shielding coating layer71coated on the top and lateral sides of the molding resin layer50, and an extended electromagnetic shielding coating layer73extended from the basic electromagnetic shielding coating layer71and coated on the edge portion of the PCB10.

The basic electromagnetic shielding coating layer71and the extended electromagnetic shielding coating layer73of the electromagnetic shielding coating layer70are formed at a time by a single coating process, and the extended electromagnetic shielding coating layer73is formed on the edge portion of the PCB10so as to overlap with the ground via hole11filed with the conductive material in the electromagnetic shielding structure40of the closed shield can type.

The ground pad12formed at an outer portion on the bottom of the PCB10is continuously formed in the edge portion of the PCB10and electrified connecting with the electromagnetic shielding coating layer73formed on the top of the PCB10through the ground via hole11in the electromagnetic shielding structure40of the closed shield can type. The ground pad12is provided as an input/output interface pin in the form of a land grid array (LGA) or a ball grid array (BGA), so that the SSD according to the disclosure can be finally mounted to a system board.

To achieve the electromagnetic shielding structure40of the closed shield can type, the disclosure includes the lower electromagnetic shielding layer80formed inside the PCB10, and electrically connected to the electromagnetic shielding coating layer70through the ground via hole11(i.e. the ground via holes formed along the edges of the PCB10) in the electromagnetic shielding structure40of the closed shield can type.

The lower electromagnetic shielding layer80is not attached to the bottom of the PCB10but formed inside the PCB10throughout the entire surface so as to protect itself. Like this, the lower electromagnetic shielding layer80is formed throughout the entire inner surface of the PCB10, and therefore applies the electromagnetic shielding to the bottom of the PCB10while maintaining basic protection against external impact (shock, water, heat, etc.), thereby achieving the electromagnetic shielding structure40of the closed shield can type.

The lower electromagnetic shielding layer80is necessarily formed to electrically contact the ground via hole11in the electromagnetic shielding structure40of the closed shield can type, i.e. the ground via hole11continuously formed along the edge of the PCB10, and electrically connected to the electromagnetic shielding coating layer70through the ground via hole11in the electromagnetic shielding structure40of the closed shield can type, thereby completing the electromagnetic shielding structure40of the closed shield can type.

As such, the lower electromagnetic shielding layer80for achieving the electromagnetic shielding structure40of the closed shield can type is basically protected since it is formed inside the PCB10, but may be autonomously protected against external environments and further have a structure for stable contact with the ground via hole11by its own configuration.

The lower electromagnetic shielding layer80for this purpose is illustrated inFIGS. 4 and 5.FIG. 4is a schematic cross-sectional view of the lower electromagnetic shielding layer80according to the disclosure, andFIG. 5is a schematic plan view of the lower electromagnetic shielding layer80according to the disclosure.

Further, (a) inFIG. 4shows a schematic cross-sectional view of the lower electromagnetic shielding layer80, in which a plurality of lower shielding metal pads85are formed on only the top surface of a lower shielding metal thin film81, and (b) ofFIG. 4shows a schematic cross-sectional view of the lower electromagnetic shielding layer80, in which the plurality of lower shielding metal pads85are formed on both the top and bottom surfaces of the lower shielding metal thin film81. In addition,FIG. 5shows that a lower shielding resin thin film83formed with a lower shielding opening84is coated on the lower shielding metal thin film81(to be described later), in which some lower shielding openings84are filled with the lower shielding metal pads85but the other lower shielding openings84are not filled with the lower shielding metal pad and thus expose the lower shielding metal thin film81therethrough.

As shown inFIGS. 4 and 5, the lower electromagnetic shielding layer80according to an embodiment of the disclosure basically includes the lower shielding metal thin film81; the lower shielding resin thin film83coated on at least one of the top and bottom surfaces of the lower shielding metal thin film81and formed with the plurality of lower shielding openings84; and the plurality of lower shielding metal pads85filled and coated in the plurality of lower shielding openings84and being in contact with the lower shielding metal thin film81.

Specifically, the lower electromagnetic shielding layer80according to an embodiment of the disclosure includes the lower shielding metal thin film81formed inside the PCB10throughout the entire surface and shaped like a plate. The lower shielding metal thin film81is formed like a plate throughout the entire surface of the PCB10so as to have the same area as that of the PCB10.

If the lower electromagnetic shielding layer80includes only the lower shielding metal thin film81, the lower shielding metal thin film81has a problem of being damaged or deteriorated by external impact because it may be exposed to and permeated with humidity or water and exposed to heat generated in itself or transferred heat. In this case, there are shortcomings that the performance the electromagnetic shielding structure40of the closed shield can type has is gradually deteriorated.

To solve such problems and short comings, the lower electromagnetic shielding layer80according to the disclosure includes the lower shielding resin thin film83formed as coated on the lower shielding metal thin film81. Meanwhile, the lower shielding metal thin film81has to electrically connect with the ground via hole11in the electromagnetic shielding structure40of the closed shield can type. To this end, the lower shielding resin thin film83is coated on the surface of the lower shielding metal thin film81while partially exposing the lower shielding metal thin film81.

Specifically, the lower electromagnetic shielding layer80according to the disclosure includes the lower shielding resin thin film83coated on the lower shielding metal thin film81and formed with the plurality of lower shielding openings84spaced apart from one another to expose the lower shielding metal thin film81. That is, the lower shielding resin thin film83having the plurality of lower shielding openings84is coated on the lower shielding metal thin film81, and the plurality of lower shielding openings84are arrayed leaving a predetermined space from one another.

The plurality of lower shielding openings84is filled with the lower shielding metal pads85to be in electric contact with the lower shielding metal thin film81. In other words, the lower electromagnetic shielding layer80according to the disclosure includes the plurality of lower shielding metal pads85respectively filled in the plurality of lower shielding openings84and formed to be in contact with the lower shielding metal thin film81.

Eventually, the bottoms of the lower shielding metal pads85are in contact with the lower shielding metal thin film81. The tops of the lower shielding metal pads85formed as above are in contact with and electrically connected to the ground via holes11. In particular, the lower shielding metal pads85are formed along the edge of the PCB10and electrically contact and connect with the ground via hole11in the electromagnetic shielding structure40of the closed shield can type. Meanwhile, the bottom of the lower shielding metal thin film81are entirely exposed to the outside, and therefore connected to the ground pad12as connected to the ground via hole11at a lower side.

Meanwhile, the plurality of lower shielding metal pads85may be formed each having a uniform size and arrayed to be equidistantly spaced apart from each other. Eventually, the plurality of lower shielding openings84are also formed each having a uniform size and arrayed to be equidistantly spaced apart from each other. The size of the lower shielding metal pad85is determined to guarantee stable contact and electric connection with the ground via hole11even though the SSD is changed in size or standards. Furthermore, the plurality of lower shielding metal pads85are required to be arrayed leaving the same distance from each other. To this end, each lower shielding metal pad85may have a width of 33 μm and a length of 33 μm, and a distance between the adjacent lower shielding metal pads85may be 16 μm.

In the lower electromagnetic shielding layer80shown in (a) ofFIG. 4, the bottom of the lower shielding metal thin film81is entirely exposed, and thus still affected by external impact and environmental conditions (humidity, moisture, water, heat, etc.).

Accordingly, the lower electromagnetic shielding layer80according to the disclosure, as shown in (b) ofFIG. 4, includes the lower shielding resin thin film83coated on the lower shielding metal thin film81, particularly on both the top and bottom surfaces of the lower shielding metal thin film81, and formed with the plurality of lower shielding openings84through which the lower shielding metal thin film81are exposed at predetermined intervals. Here, the plurality of lower shielding openings84are arrayed as spaced apart from each other at the same intervals.

In this case, the lower shielding resin thin film83is coated on both surfaces, i.e. the top and bottom surfaces of the lower shielding metal thin film81, and includes the lower shielding openings84arrayed at the same intervals. Even in this case, as shown in (b) ofFIG. 4, the lower electromagnetic shielding layer80according to the disclosure includes the plurality of lower shielding metal pads85respectively filled in the plurality of lower shielding openings84and being in contact with the lower shielding metal thin film81. Here, the plurality of lower shielding metal pads85are formed as filled in the lower shielding openings84formed on the top and bottom surfaces of the lower shielding metal thin film81.

Eventually, the plurality of lower shielding metal pads85are in contact with and electrically connected to the lower shielding metal thin film81at the top and bottom surfaces of the lower shielding metal thin film81. Therefore, the lower shielding metal pads85formed in contact with the top surface of the lower shielding metal thin film81are in upward contact and connection with the ground via hole11and electrically connected to the electromagnetic shielding coating layer70, and the lower shielding metal pads85formed in contact with the bottom surface of the lower shielding metal thin film81are in downward contact and connection with the ground via hole11and electrically connected to the ground pad12.

Like this, as shown in (b) ofFIG. 4, the lower shielding resin thin film83is coated on the top and bottom surfaces of the shielding metal thin film81, thereby maximizing the protection and performance of the shielding metal thin film81as compared with those in (a) ofFIG. 4. Meanwhile, the plurality of lower shielding metal pads85applied in this case has the same size and interval as those described with reference to (a) ofFIG. 4.

In the SSD according to the disclosure, a communication modem chip34for communication based on Wi-Fi, long term evolution (LTE), Bluetooth, etc. may be additionally mounted to the PCB10as shown inFIG. 6. The plurality of memories30including the plurality of stacked flash memories31and the DDR memory32, the controller33, the plurality of active and passive elements35, and the communication modem chip34may exchange thermal interference or electromagnetic interference as they are arranged on the PCB10.

According to the disclosure, the controller33is mounted to one side on the top surface of the PCB10, the communication modem chip34is mounted to the other side, and an interference blocker90is formed to block electromagnetic interference between the controller33and the communication modem chip34.

Specifically, as shown inFIGS. 6 to 8, the SSD100according to an embodiment of the disclosure includes the communication modem chip34additionally mounted to the PCB10, and further includes the interference blocker90formed penetrating the molding resin layer50so as to spatially divide the top surface of the PCB10into one side and the other side and block the electromagnetic interference between the communication modem chip34and the controller33.

The interference blocker90may have various structure as long as it can electrically separate an area where the controller33is mounted (i.e. a first area) from an area where the communication modem chip34is mounted (i.e. a second area) in order to block the electromagnetic interference between the communication modem chip34and the controller33.

Because the electromagnetic shielding coating layer70is electrically connected to the lower electromagnetic shielding layer80and the ground pad12through the ground via hole11, the interference blocker90electrically connected to the electromagnetic shielding coating layer70is also electrically connected to the electromagnetic shielding coating layer70and the lower electromagnetic shielding layer80and further connected to the ground pad12through the ground via hole11, thereby performing the electromagnetic shielding function of the closed shield can type.

As described above, the interference blocker90may include a divider plate made of a metal plate or a plastic plate coated with a conductive material. Alternatively, as shown inFIGS. 7 and 8, the interference blocker90may include an interference blocking via hole91formed penetrating the molding resin layer50. The interference blocking via hole91is continuously formed vertically penetrating the molding resin layer50so as to electrically divide the first area and the second area. Of course, the interference blocking via hole91filled with a conductive material may be electrically connected to a separate ground via hole formed in the PCB10and connected to the ground pad12through the lower electromagnetic shielding layer80formed inside the PCB10.

The SSD100according to an embodiment of the disclosure shown inFIGS. 6 to 8is the same as the foregoing SSD shown inFIGS. 1 to 5except the interference blocker90including the interference blocking via hole91filled with the conductive material, and thus repetitive descriptions thereof will be avoided.

With the electromagnetic shielding structure of the SSD according to the disclosure for the technical problems and solutions, an electromagnetic shielding structure of a closed shield can type is achieved based on an electromagnetic shielding structure that employs an electromagnetic shielding coating layer electrically connected to a ground via hole formed in a printed circuit board (PCB) and a lower electromagnetic shielding layer formed inside the PCB and electrically connected to the electromagnetic shielding coating layer through the ground via hole, thereby improving electromagnetic shielding performance.

Although embodiments of the disclosure have been described, these are for illustrative purpose only and it will be appreciated by a person having an ordinary skill in the art that various changes and their equivalents may be made in these embodiments. Therefore, the scope of the disclosure is defined in the following claims.