EMI shielding structure and manufacturing method therefor

An electromagnetic interference (EMI) shielding structure and a method for manufacturing are provided. The EMI shielding structure includes a printed circuit board (PCB) on which a plurality of elements are mounted, an insulation molding member configured to cover the plurality of elements, a conductive shielding dam formed along a side surface of the insulation molding member, and a conductive shielding member formed on a top surface of the insulation molding member.

TECHNICAL FIELD

The present disclosure relates to an electromagnetic interference (EMI) shielding structure and a method for manufacturing the EMI shielding structure. More particularly, the present disclosure relates to a method for manufacturing an EMI shielding structure, which forms an insulation molding member using a mold and forms a shielding material for covering the insulation molding member.

BACKGROUND

Currently, the demand for portable devices in electronic product markets is increasing, and also, there has been a continuous demand for miniaturizing and lightening of portable devices to make them easy to carry. In order to miniaturize and lighten portable devices, packaging technology for integrating a plurality of circuit elements mounted on a printed circuit board (PCB) into a single package, as well as technology for reducing the sizes of individual electronic components provided in the portable devices are essential. In particular, a semiconductor package which deals with high frequency signals advantageously includes various electromagnetic interference (EMI) shielding structures in order to improve implementation of EMI or electromagnetic wave resistance characteristics as well as aid in miniaturization.

To achieve this, a related-art EMI shielding structure includes a structure which covers various circuit elements with a shield can made of press-processed metal, and a structure which forms a shielding dam made of a conductive material to enclose circuit elements, covers all the circuit elements by injecting an insulator into the shielding dam, and then forms a shielding layer thereon.

In the shielding structure applying the shield can, the shield can should have a constant thickness to maintain its shape, and should be spaced from each circuit element by a predetermined distance to prevent a short from the circuit element. However, due to the thickness of the shield can and the distance between the shield can and the circuit element, there is a limit to reducing the height of the shield can. Such a limit may be a factor that hinders miniaturization of the shielding structure. In addition, an air gap is formed between the shield can and the circuit element. The air gap performs an insulation action for hindering heat emitted from the circuit element from being discharged. In order to emit heat smoothly, air vents should be formed on the upper portion or side portion of the shield can. However, since electromagnetic waves leak through the air vents formed on the shield can, there is a problem that the EMI shielding effect is reduced.

In addition, as the technology develops, high density mounting is increasingly used. In this case, since a gap between circuit elements is set to be very narrow, it is difficult to manufacture a shielding dam satisfying a required width to height ratio by a related-art process.

SUMMARY

Aspects of the present disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present disclosure is to provide an electromagnetic interference (EMI) shielding structure and a method for manufacturing the EMI shielding structure, which can be applied to a printed circuit board (PCB) in which circuit elements are high density mounted by forming a shielding dam, leaning on an insulation molding member for covering the circuit elements.

Another aspect of the present disclosure is to provide a mold sealing method which can prevent an insulation material injected into a mold from leaking between the mold and a PCB, and an EMI shielding structure and a method for manufacturing the EMI shielding structure using the same.

In accordance with an aspect of the present disclosure, an EMI shielding structure is provided. The EMI shielding structure includes a PCB on which a plurality of elements are mounted, an insulation molding member configured to cover the plurality of elements, a conductive shielding dam formed along a side surface of the insulation molding member, and a conductive shielding member formed on a top surface of the insulation molding member.

The shielding dam may have a longitudinal section formed in a shape of “” to cover the side surface and the top surface of the insulation molding member.

A width to height ratio of the shielding dam may be greater than or equal to 1:3. In this case, a viscosity of a material forming the shielding dam may be greater than or equal to 20,000 cps.

A mounting gap between the elements may be less than or equal to 0.8 mm.

An inclination of an inner surface of the shielding dam may be the same as an inclination of the side surface of the insulation molding member. The inner surface of the shielding dam may be formed vertically or slantly.

The conductive shielding member may be a conductive shielding film which is attached to the top surface of the insulation molding member.

The conductive shielding member may be formed of a liquid conductive shielding material which is discharged by a nozzle and coated on the top surface of the insulation molding member.

The EMI shielding structure may further include an edge bridge which has electrical conductivity and covers a portion where the shielding dam and the conductive shielding member mutually contact each other.

The shielding dam may have a lower end electrically connected with a ground formed on the PCB.

In accordance with another aspect of the present disclosure, an EMI shielding structure is provided. The EMI shielding structure includes a PCB on which a plurality of elements are mounted, a mold which is seated on the PCB to enclose the plurality of elements, an insulation molding member which is molded after being injected into the mold and covers the plurality of elements, a conductive shielding dam which is formed along a side surface of the mold, and a conductive shielding member which covers a top surface of the mold and a top surface of the insulation molding member.

The shielding dam may have a longitudinal section formed in a shape of “” to cover the side surface and the top surface of the mold.

A sealant may be disposed between the lower end of the mold and the top surface of the PCB.

In accordance with another aspect of the present disclosure, a method for manufacturing an EMI shielding structure is provided. The method includes providing a liquid sealant to a mold, setting the mold to bring the liquid sealant into contact with a surface of a PCB on which a circuit element is mounted, forming an insulation molding member for covering the circuit element by injecting an insulation material into the mold, removing the mold from the PCB, and forming a conductive shielding material for covering the insulation molding member.

In accordance with another aspect of the present disclosure, a method for manufacturing an EMI shielding structure is provided. The method includes setting a mold to be spaced from a PCB on which a circuit elements is mounted, injecting a liquid sealant between the mold and the PCB, forming an insulation molding member for covering the circuit element by injecting an insulation material into the mold, removing the mold from the PCB, and forming a conductive shielding material for covering the insulation molding member.

In accordance with another aspect of the present disclosure, a method for manufacturing an EMI shielding structure is provided. The method includes setting a mold having a lower end connected with a sealant on a PCB on which a circuit element is mounted, forming an insulation molding member for covering the circuit element by injecting an insulation material into the mold, and forming a conductive shielding material for covering both the mold and the insulation molding member.

In accordance with another aspect of the present disclosure, a nozzle for forming a shielding dam by discharging a conductive material is provided. The nozzle includes an outlet through which the conductive material is discharged, and a guide portion extending from one side of the outlet in a longitudinal direction of the nozzle.

DETAILED DESCRIPTION

It will be understood that when an element is referred to as being “on” or “in contact with” another element, the element can directly contact or be connected with another element, and there is an intervening element therebetween. In addition, it will be understood that when an element is referred to as being “directly on” or “in direct contact with” another element, there is no intervening element therebetween. Other expressions explaining relationships between the elements, for example, “between”, “directly between,” or the like, will be understood likewise.

The terms such as “first” and “second” used in various embodiments may be used to explain various elements, and the elements should not be limited by these terms. These terms may be used for the purpose of distinguishing one element from another element. For example, a first element may be named a second element without departing from the scope of right of various embodiments of the present disclosure, and similarly, a second element may be named a first element.

The terms “include” or “have” indicate the presence of features, numbers, operations, elements, and components described in the specification, or a combination thereof, and do not preclude the addition of one or more other features, numbers, operation, elements, or components, or a combination thereof.

The terms used in describing the various embodiments will be interpreted as having meanings well known to a person skilled in the art unless otherwise defined.

An electromagnetic interference (EMI) shielding structure according to various embodiments may be applied to a smart phone, a display device, a wearable device, and the like.

The EMI shielding structure according to various embodiments forms an insulation molding member using a mold, and forms a shielding dam by moving a nozzle along the side portion of the insulation molding member. Since the shielding dam is formed leaning on the side portion of the insulation molding member, the shielding dam may be formed with a high width to height ratio. When the shielding dam is formed along the side portion of the insulation molding member as described above, a portion of the nozzle through which a material is discharged can have a narrow width, such that the EMI shielding structure can be applied to a highly integrated mounting substrate in which circuit elements have a very narrow gap therebetween.

In addition, the EMI shielding structure according to various embodiments may apply a liquid sealant in order to prevent an insulation material injected into the mold from leaking via a gap formed between the mold and the printed circuit board (PCB). The liquid sealant may be evaporated at a temperature higher than a curing temperature of the insulation molding member according to the material, and may be removed from the PCB. When the liquid sealant is formed of a material which is not evaporated, the liquid sealant may be removed from the PCB through post-processing after the insulation molding member is cured.

In addition, the EMI shielding structure according to various embodiments shields a plurality of circuit elements. However, this should not be considered as limiting and the EMI shielding structure may be formed to shield only a single circuit element.

Hereinafter, the structure of the above-described nozzle and the process of forming the shielding dam using the nozzle, and an example of using the liquid sealant when forming the insulation molding member will be described in detail with reference to the accompanying drawings.

FIG. 1Ais a cross section view illustrating an EMI shielding structure according to an embodiment of the present disclosure.

Referring toFIG. 1A, an EMI shielding structure100may include a PCB110and a plurality of circuit elements115,117, and119which are mounted on the PCB110. The plurality of circuit elements, which are heterogenous circuit elements, may include integrated circuit (IC) chips, passive elements, and heterogenous components. For example, the IC chip may be an application processor (AP), a memory, a radio frequency (RF) chip, and the like, the passive element may be a resistor, a capacitor, a coil, and the like, and the heterogenous component may be a connector, a card socket, an EMI shielding component, and the like.

A first connection pad111and a second connection pad112may be patterned on the top surface of the PCB110to be electrically connected with the plurality of circuit elements115,117, and119. A plurality of first connection pads111and a plurality of second connection pads112may be formed. The first and second connection pads111and112may be formed to ground the plurality of circuit elements115,117, and119or transmit signals.

A ground pad114may be patterned on the PCB110. The ground pad114may be formed inside the PCB110with the top surface thereof being exposed so as to prevent the top surface of the PCB110from being exposed. In this case, the ground pad114may be integrally formed with a ground layer (not shown) formed inside the PCB110.

The ground pad114may be formed to ground the plurality of circuit elements115,117, and119or transmit signals. A shielding dam130, which will be described below, may be grounded along a forming path of the shielding dam130or by electrically connecting with the ground pad114formed on a part of the forming path, when the shielding dam130is formed on the PCB110.

The circuit element115may include a plurality of connection terminals116which are electrically connected with the first connection pads111of the PCB110. The plurality of connection terminals116may be formed in a ball grid array (BGA) method like a solder ball. However, the connection terminals116are not limited to the BGA method and may be formed in various methods, for example, quad flat no lead (QFN), plastic leaded chip carrier (PLCC), quad flat package (QFP), small out line package (SOP), thin/shrink/thin shrink SOP (TSOP/SSOP/TSSOP), according to a lead shape of the element115.

The other circuit elements117and119may include at least one connection terminal (not shown) which is electrically connected with the second connection pad112of the PCB110. The plurality of circuit elements117and119may be lower than or higher than the circuit element115described above when being mounted on the PCB110. Each of the circuit elements115,117, and119may be spaced from the shielding dam130by a predetermined distance so as not to be brought into contact with the shielding dam130.

The EMI shielding structure100according to an embodiment may include an insulation molding member120for covering the plurality of circuit elements115,117, and119, the shielding dam130formed along the side portion of the insulation molding member120, and a shielding member140formed on the top surface of the insulation molding member120.

The insulation molding member120may insulate between the circuit elements115,117, and119, between each circuit element115,117,119and the shielding dam130, and between each circuit element and the shielding member140.

The insulation molding member120may be formed by injecting an insulation material into a mold10and curing the insulation material. In this case, the insulation material may be in close contact with the outer surfaces of the circuit elements115,117, and119, and may be formed of a material having fluidity so as to flow into a gap formed between each of the circuit elements115,117,119and the PCB. The insulation molding member120may be cured through various curing processes such as room temperature vulcanization, thermal curing, UV curing, or the like.

The insulation material may be a thixotropy material or a phase change material (a thermoplastic material or a thermosetting material) having fluidity.

The thixotropy material may include at least one of synthetic micronised silica, bentonite, particle-surface treated calcium carbonate, hydrogen-added castor oil, metal soap, aluminum stearate, polyamide wax, polyethylene oxide, and linseed polymerized oil. For example, the metal soap may include aluminum stearate.

The phase change material may include at least one of polyurethane, polyurea, polyvinyl chloride, polystyrene, acrylonitrile butadiene styrene (ABS), polyamide, acrylic, epoxy, silicone, and polybutylene terephthalate (PBTP).

The shielding dam130may be formed along the side portion of the insulation molding member120which is cured. In this case, the shielding dam130may be formed leaning on the side portion of the insulation molding member120, and may cover the side surface of the insulation molding member120and a part of the top surface of the insulation molding member120. When the shielding dam130is formed leaning on a predetermined structure like the insulation molding member120as described above, the shielding dam130may have a higher width to height ratio than when the shielding dam130is formed to form a shape by itself without leaning on a separate structure, that is, in a free standing type. Herein, the width to height ratio of the shielding dam is a value which is obtained by dividing the height of the shielding dam130by the width of the shielding dam. When the shielding dam130formed leaning on the side surface of the insulation molding member120as described above has a viscosity greater than or equal to about 20,000 cps, the shielding dam130may be formed to have a width to height ratio higher than or equal to 1:3. On the other hand, when the shielding dam130formed in the free standing type has a viscosity greater than or equal to about 80,000 cps, the shielding dam130may be formed to have a width to height ratio higher than or equal to 1:2. Accordingly, when the shielding dam130is formed leaning on the side surface of the insulation molding member120as in the above-described embodiment and has a lower viscosity, the shielding dam130may have a higher width to height ratio than when the shielding dam130is formed in the free standing type.

The shielding dam130may be formed of a conductive material having an EMI shielding characteristic which can prevent an EMI. Accordingly, the shielding dam130can prevent the EMI in advance, which may influence other electronic components in an electronic device including the EMI shielding structure100, by blocking electromagnetic waves generated in the plurality of circuit elements115,117, and119. Interference such as an electromagnetic wave noise or malfunction can be ultimately blocked in the electronic device including the EMI shielding structure100, such that the reliability of a product can be prevented from being reduced. As described above, the shielding dam130may prevent electromagnetic waves which are unavoidably generated during the operating process of the circuit elements115,117, and119from influencing the outside.

The conductive material may have a high viscosity (greater than or equal to 100,000 cps), such that the shielding dam130is formed to have a high width to height ratio and maintains a shape at the time of being discharged without flowing down. When the material has a high viscosity as described above, the width to height ratio of the shielding dam130can be increased and thus the height of the shielding dam can be increased.

In addition, in the case of a double-sided PCB, the shielding dam may be formed on the front surface and then the PCB may be turned over to have the shielding dam formed on the rear surface thereof. In this case, when a conductive material having a high viscosity is used, the shielding dam formed on the front surface may not flow down and maintain its shape as it is. Accordingly, there is an advantage that the entire work process can be proceeded rapidly.

Specifically, the conductive material for forming the shielding dam130may be an electroconductive material having electrical conductivity greater than or equal to 1.0E+04 S/m. Such an electroconductive material may include an electroconductive filler and a binder resin.

The electroconductive filler may use metal such as Ag, Cu, Ni, Al, Sn, or the like, use conductive carbon such as carbon black, carbon nanotube (CNT), graphite, or the like, use metal coated materials such as Ag/Cu, Ag/Glass fiber, Ni/Graphite, or the like, or use a conducting polymer material such as polypyrrole, polyaniline, or the like. In addition, the electroconductive filler may be formed in any one or a combination of a flake type, a sphere type, a rod type, and a dendrite type.

The binder resin may use a silicon resin, an epoxy resin, a urethane resin, an alkyd resin, or the like. The material for forming the shielding dam130may additionally contain an additive (a viscosity agent, an antioxidant, a polymer surfactant, or the like) and a solvent (water, alcohol, or the like) to enhance other functions.

FIGS. 1B and 1Care views illustrating a structure in which an inner surface of a shielding dam is formed vertically or slantingly according to various embodiments of the present disclosure.

Referring toFIGS. 1A to 1C, the shielding dam130may be formed leaning on the side portion of the insulation molding member120, and cover the side surface of the insulation molding member120and a part of the top surface of the insulation molding member120. Accordingly, the longitudinal section of the shielding dam130is formed in the shape of “” as illustrated inFIG. 1B. In this case, an inner surface130cof the shielding dam130may have the same inclination as that of a side surface120cof the insulation molding member120. When the side surface120cof the insulation molding member120is perpendicular to the top surface of the PCB110as illustrated inFIG. 1B, the inner surface130cof the shielding dam130may be perpendicular. In addition, when the insulation molding member120is formed to have the lower portion longer than the upper portion as illustrated inFIG. 1Cand thus a side surface120dof the insulation molding member120is inclined, an inner surface130dof the shielding dam130may have the same inclination as that of the side surface120dof the insulation molding member120. On the other hand, when the shielding dam is formed in the free standing type (the shielding dam is formed to have a predetermined width to height ratio without leaning on a separate structure), the width of the lower side of the shielding dam may be larger than the width of the upper side. Accordingly, the inner surface of the shielding dam formed in the free standing type has an inclination in a direction opposite to the inclination direction of the inner surface130dof the shielding dam130of the embodiment.

Referring toFIG. 1B, an upper end130eof the shielding dam130formed on the upper side of the insulation molding member120is brought into contact with an edge140eof the shielding member140, such that the shielding dam130can completely cover the outer surface of the insulation molding member120. In this case, a part of the upper end130eof the shielding dam130may be covered by the edge140eof the shielding member140.

The shielding member140may be formed of a conductive material having fluidity like the shielding dam130, and may be formed of the same material as the above-described material of the shielding dam130.

The shielding member140may be formed on the top surface of the insulation molding member120. When the shielding dam130is formed along the side portion of the insulation molding member120, an upper end131of the shielding dam130protrudes to be higher than the top surface of the insulation molding member120. Accordingly, a space for filling with the shielding member140may be provided on the top surface of the insulation molding member120.

When the top surface of the insulation molding member120is filled with the shielding member140, the shielding member140may be brought into contact with the upper end131of the shielding dam130and electrically connected therewith. Accordingly, the shielding dam130and the shielding member140completely encloses the outer side of the insulation molding member120, such that an optimal shielding structure can be achieved.

Hereinafter, a manufacturing process of the EMI shielding structure100according to an embodiment will be described in sequence with reference toFIGS. 2A to 2F.

FIGS. 2A to 2Fare views illustrating a manufacturing process of an EMI shielding structure in sequence according to various embodiments of the present disclosure.

FIG. 3is a view illustrating an example of a process of forming a shielding dam on a side portion of an insulation molding member using a nozzle on a PCB, in which circuit elements are high-density mounted according to an embodiment of the present disclosure.

Referring toFIGS. 2A and 2B, when the PCB110on which the plurality of circuit elements115,117, and119are mounted is loaded into a work position as illustrated inFIG. 2A, a mold10is arranged on a position of the PCB110where the insulation molding member120is to be formed as illustrated inFIG. 2B.

Referring toFIG. 2C, an insulation material having fluidity is injected into an inside11of the mold10, and then the PCB110is put into an oven (not shown) and heated at a predetermined temperature during a predetermined time in order to cure the insulation material. The insulation material cured in the inside11of the mold10becomes the insulation molding member120.

Referring toFIG. 2D, in response to the insulation molding member120being formed, the PCB110is drawn out from the oven and then the mold10is removed from the PCB110.

Referring toFIGS. 2E and 2F, the shielding dam130for covering the side surface of the insulation molding member120and a part (edge) of the top surface of the insulation molding member120is formed by continuously discharging a predetermined amount of conductive material along the side portion of the insulation molding member120as illustrated inFIG. 2E. The insulation molding member120has the shielding member140formed on the upper surface of the insulation molding member120as illustrated inFIG. 2F. The conductive material is discharged from a nozzle216(seeFIG. 3) which moves along the side portion of the insulation molding member120.

Referring toFIG. 3, the nozzle216has an outlet216aformed at the lower end thereof, and a guide portion216bextends from one side of the outlet216ato a predetermined length in a longitudinal direction of the nozzle216. In this case, the nozzle216may be disposed such that the outlet216ais higher than the top surface of the insulation molding member120and the guide portion216bpasses between the side surface of the insulation molding member120and a predetermined circuit element20. The guide portion216bguides the material discharged from the outlet216ato move toward the side surface of the insulation molding member120.

The shape of the portion of the nozzle216through which the material is discharged is formed taking into consideration that the nozzle216should be moved smoothly on the highly integrated mounting PCB. That is, in the case of the highly integrated mounting PCB, a gap (g1) between the circuit element115and the circuit element20is designed to be very narrow, less than or equal to 0.8 mm. When it is assumed that the gap (g1) between the elements is 0.8 mm, an outer diameter (D) of the nozzle216may be set to 0.9 mm, a thickness (t) may be set to 0.1 mm, and an inner diameter (d) may be set to 0.8 mm. Herein, the inner diameter (d) of the nozzle216may be the same as the diameter of the outlet216a.The guide portion216bdownwardly extending from the outlet216amay have a predetermined length (L) and a predetermined width (w). In this case, the width (w) of the guide portion216bwill be enough as long as a gap between one side of the guide portion216aand the side surface of the insulation molding member120is maintained and a gap between the other side of the guide portion216band the circuit element20is maintained when the guide portion216bis disposed between the side surface of the insulation molding member120and the circuit member20. For example, when a distance (g2) from the other side of the guide portion216bto the side surface of the insulation molding member120is 0.5 mm, a gap (g3) between one side of the guide portion216band the side surface of the insulation molding member120may be maintained as 0.1 mm.

A part of the material discharged through the outlet216ais discharged in contact with the guide portion216b.In this case, the part of the material contacting the guide portion216bmay generate a frictional resistance between the material and the guide portion216bwhile contacting the inner surface of the guide portion216b,and the other part of the material that does not contact the guide portion216bdoes not generate a frictional resistance by the guide portion216bor is hardly influenced by the frictional resistance and thus the material is discharged rather rapidly.

As described above, a phenomenon in which there is a difference in the discharging speed when the material discharged through the outlet216aescapes from the outlet216aarises. The length (L) of the guide portion216bmay be set in consideration of such a phenomenon. For example, the nozzle216may continuously discharge the material through the outlet216awhile moving along the side portion of the insulation molding member120at constant speed. In this case, when the length of the guide portion216bis too long, a part of the material adjacent to the guide portion216bout of the material discharged from the outlet216amoves toward the insulation molding member120before it is guided to the lower end of the guide portion216b.To this end, the shielding dam130may have a thin lower portion in comparison to the upper portion or may not cover the lower portion of the side surface of the insulation molding member120. In addition, when the length of the guide portion216bis too short, the lower portion of the shielding dam130may be thicker than the upper portion or the shielding dam130may not cover the upper portion of the side surface of the insulation molding member120. Accordingly, since the length (L) of the guide portion216bmay influence the forming of the shielding dam130, the length (L) of the guide portion216bmay be formed appropriately in consideration of the height of the insulation molding member120.

In addition, the inner surface of the guide portion216bmay be formed to face the insulation molding member120in order to move the material discharged through the outlet216atoward the insulation molding member120when the nozzle216moves along the insulation molding member120to form the shielding dam130.

FIG. 4is a block diagram illustrating a material discharge device for forming a shielding structure according to an embodiment of the present disclosure.

The material discharge device for forming the EMI shielding structure according to an embodiment may be a 3D printer.

Referring toFIG. 4, a material discharge device200may include one nozzle216by way of an example. However, this should not be considered as limiting and the material discharge device200may include a plurality of nozzles. In particular, the material discharge device200may include a plurality of nozzles having guide portions216bof different lengths in order to form shielding dams130having different heights on the side portion of the insulation molding member120.

The material discharge device200may include a dispenser212to discharge a predetermined amount of material. The dispenser212may include a storage chamber211for storing the material, and the nozzle216for discharging the material supplied from the storage chamber211.

In addition, the dispenser212may include an X-Y-Z-axis movement unit231for moving the nozzle216in the X-axis, Y-axis, and Z-axis directions, and a rotation driver219for rotating the nozzle216in a clockwise direction or in a counter clockwise direction or stopping rotating. The X-Y-Z-axis movement unit231may include a plurality of motors (not shown) for moving the nozzle216in the X-axis, Y-axis and Z-axis directions, and may be connected to a nozzle mounting unit (not shown) in which the nozzle216is mounted in order to forward the driving force of the step motors to the nozzle216. The rotation driver219may include a motor (not shown) for providing rotating power and an encoder (not shown) for controlling the rotation angle of the nozzle216by sensing the number of rotation of the motor. The X-Y-Z-axis movement unit231and the rotation driver219may be electrically connected to a controller250and may be controlled by the controller250.

In the material discharge device200, the end of the nozzle through which the material is discharged may not exactly coincide with a pre-set setting position when the outlet of the nozzle216is cleaned or the nozzle216is replaced with new one. Accordingly, a nozzle position detection sensor232is provided to set the nozzle216in the setting position.

The nozzle position detection sensor232may use a vision camera and may be spaced from the lower side of the nozzle216by a predetermined distance. The position of the end of the nozzle may be read through an image captured by the nozzle position detection sensor232with reference to the calibration of the nozzle, and may be compared with an origin point value of the nozzle pre-stored in a memory251, and the nozzle216may be moved as much as difference values on the X and Y axes, such that the end of the nozzle is made to coincide with the origin point of the nozzle. In this case, the nozzle216may be moved by moving the nozzle mounting unit by driving the X-Y-Z-axis movement unit231.

When the PCB is loaded into a location for forming the shielding dam, the material discharge device200may detect the posture of the PCB in the X-Y plane state in which the PCB is laid, and may set a starting point (Ap) of the nozzle216for discharging the material. The material discharge device200may include a PCB reference position detection sensor233and a PCB height detection sensor234in order to detect the posture of the PCB after loading the PCB.

The PCB reference position detection sensor233is a sensor for determining a PCB loading home position, and may use a vision camera. The PCB reference position detection sensor233may detect whether the PCB loaded into a work space to form the shielding structure is in a pre-set position or how much the PCB deviates from the pre-set position. For example, when the PCB is loaded into the work position, the controller250may move the PCB reference position detection sensor233to coordinates of a pre-set first reference mark, capture the first reference mark of the PCB, and then compare the currently captured first reference mark and the pre-set first reference mark, and the PCB reference location detection sensor233may determine whether the PCB is in the home position or not.

In response to the PCB reference position detection sensor233determining that the PCB is in the home position, the controller250may calculate a location difference between the coordinates of the current first reference mark and the coordinates of the pre-set first reference mark. The controller250may calculate a location difference between the coordinates of a current second reference mark and the coordinates of a pre-set second reference mark in the same method as the method of calculating the coordinates of the first reference mark.

The material discharge device200may include a PCB supply and discharge unit235for loading the PCB into a work position to form the shielding dam on the PCB, and unloading the PCB after forming the shielding dam.

The material discharge device200may include a PCB heater236to heat the PCB to a predetermined temperature in order to reduce time required to dry the formed shielding dam130.

The material discharge device200may include the inputter253through which a user directly inputs the moving path of the nozzle216.

The inputter253may be implemented by using a touch screen through which a touch input is possible, or a typical key pad. The user may input the path of the nozzle through the inputter253. For example, the user may input the path of the nozzle one time, and the path data of the nozzle inputted in this way may be stored in the memory251. The path data of the nozzle may be modified afterward.

A process of inputting the path of the nozzle through the inputter253as described above will be described below.

First, at least two reference marks displayed on the PCB loaded into the work position are captured using the PCB reference position detection sensor233(for example, may be a vision camera and referred to as a vision camera hereinafter), a distance between the two reference marks is measured, and then a distance value between the two reference marks is stored in the memory251with images of the references. When the PCB has a rectangular shape, the two reference marks may be displayed at the upper end of the left side of the PCB and the lower end of the right side of the PCB. In this case, the distance between the two reference marks may substantially indicate the length of a diagonal line of the PCB.

Specifically, in response to the PCB being loaded into the work position, the user may move the vision camera to the position of the first reference mark (for example, with reference to the center of the first reference mark or a part of the first reference mark) displayed at the upper end of the left side through forward, backward, left, and right buttons of the inputter253, and then, in response to a save button of the inputter253being pressed, the controller250may acquire coordinates (X1, Y1, Z1) of the first reference mark by calculating a distance of the first reference mark from a pre-set origin point (0,0,0), and store the coordinates in the memory251. A capturing location of the vision camera which moves with the nozzle may be offset from the center of the nozzle by a predetermined distance. Accordingly, the coordinates (X1, Y1, Z1) of the first reference mark may be calculated by the controller250in consideration of the offset value. In addition, in response to the user pressing a capture button, an image of the first reference mark is stored in the memory251.

The user may move the vision camera to the position of the second reference mark (for example, with reference to the center of the second reference mark or a part of the second reference mark) displayed at the lower end of the right side through the forward, backward, left, and right buttons of the inputter253, and then, in response to the save button of the inputter253being pressed, the controller250may acquire coordinates (X2, Y2, Z2) of the second reference mark by calculating a distance of the second reference mark from the pre-set origin point (0,0,0), and store the coordinates in the memory251. In addition, in response to the user pressing the capture button, an image of the second reference mark is stored in the memory251. The coordinates (X2, Y2, Z2) of the second reference mark may be calculated by the controller250in consideration of the offset value in the same way as in the process of calculating the coordinates (X1, Y1, Z1) of the first reference mark described above.

The controller250may calculate a distance between the two positions using the positions of the first and second reference marks detected as described above, and store the distance in the memory251.

The user may move the vision camera along the path of the shielding dam to be formed on the PCB using the forward, backward, left, and right buttons of the inputter253, and may input a plurality of coordinates located on the moving path of the nozzle while checking real-time images captured by the vision camera with naked eyes. Corresponding coordinates may be inputted by pressing a coordinates' input button of the inputter253when the vision camera is located at a certain point on the moving path of the nozzle. The coordinates inputted in this way are stored in the memory251.

As will be described below, the plurality of coordinates may include coordinates of a point (Ap, seeFIG. 5) at which the nozzle starts discharging the material, coordinates of a point at which the nozzle finishes discharging (almost adjacent to the starting point (Ap) when the shielding dam is formed, drawing a closed curve line), and coordinates of points (Bp, Cp, Dp, Ep, and Fp, seeFIG. 5) at which the nozzle should change the direction while moving.

In addition, in order to program the moving path of the nozzle, the inputter253may include various command buttons, such as a move button to move the nozzle to designated coordinates, a line button to instruct the nozzle to move while discharging the material, and a rotate button to change the moving direction of the nozzle. The user may generate the moving path of the nozzle by matching the command buttons and the coordinates and rotation angles.

In response to the moving path of the nozzle being programmed by the user as described above, the controller250may automatically form the shielding dam by discharging the material while moving the nozzle along the moving path.

The nozzle path data inputted through the inputter253as described above may be stored in the memory251. The controller250may move the nozzle along the previously inputted path by driving the X-Y-Z-axis movement unit231and the rotation driver219according to the nozzle path data stored in the memory251. The nozzle path data may include a distance by which the nozzle216is moved straightly along the top surface of the PCB110, and a rotation direction and an angle of the nozzle216.

In the present embodiment, the user directly inputs the moving path of the nozzle through the inputter253. However, this should not be considered as limiting, and the nozzle moving path may be pre-stored in the memory251. In this case, a plurality of nozzle moving paths corresponding to patterns of the shielding dam formed variously according to products may be pre-stored to correspond to the patterns. In addition, calibration information, reference position information of the nozzle, PCB reference position information, PCB reference height information may be pre-stored in the memory251through the inputter253in addition to the moving path of the nozzle.

FIG. 5is a view illustrating a moving path of the nozzle which is inputted through an inputter provided in a material discharge device according to an embodiment of the present disclosure.

Referring toFIG. 5, the nozzle216may be moved along the path for forming the shielding dam based on the nozzle path data.

The nozzle216is set at coordinates corresponding to the starting point (Ap). In this case, the controller250may determine a direction in which the molding member120is disposed, and rotate the nozzle216by a predetermined angle by driving the rotation driver219such that the inner surface of the guide portion216faces the side surface of the insulation molding member120.

The nozzle216set at the coordinates corresponding to the starting point (Ap) is linearly moved by the X-Y-Z-axis movement unit231as much as a section A in the +Y axis direction. Next, the nozzle216moves along a section where the path curves (a section including a point (Bp) connecting the section A and a section B). In this case, at the same time of being moved along the nozzle path by the X-Y-Z-axis movement unit231, the nozzle261may be rotated by the rotation driver219such that the inner surface of the guide portion216bkeeps facing the insulation molding member120.

In response to the nozzle216passing the section where the path curves, the nozzle216is linearly moved by the X-Y-Z-axis movement unit23as much as the section B in the -X-axis direction. In this way, the nozzle216may be linearly moved and rotated by the rotation driver219and the X-Y-Z-axis movement unit231through the other sections B, C, D, E, and F, and then return to the starting point (Ap). Then, the nozzle216finishes moving along the path.

FIG. 6is a view illustrating an outlet through which a material for forming a shielding dam is discharged from a nozzle of a material discharge device according to an embodiment of the present disclosure.

Referring toFIG. 6, the nozzle216discharges the material through the outlet216awhile being moved by the X-Y-Z-axis movement unit231and being rotated by the rotation driver219.

The outlet216amay be formed toward the lower side of the nozzle216and the guide portion216bmay downwardly extend from the lower end of the outlet216ain the longitudinal direction of the nozzle216.

In response to the nozzle216being set at a position for discharging the material in order to form the shielding dam130along the side portion of the insulation molding member120as illustrated inFIG. 3, the outlet216amay have a part thereof located over the top surface of the insulation molding member120such that the material covers a part (edge) of the top surface of the insulation molding member120. The guide portion216bis disposed between the insulation molding member120and the circuit element20and is disposed so as not to interfere with the insulation molding member120and the circuit element20when the nozzle216moves.

The guide portion216bguides the material discharged through the outlet216ato move toward the lower side of the insulation molding member120, and simultaneously, guides the material to move toward the insulation molding member120by preventing the material from spreading in a direction going away from the insulation molding member120.

The nozzle216forms the shielding dam130on the side surface and the top surface of the insulation molding member120while moving along the path which is pre-set to form the shielding dam130, and simultaneously, guides the material to the ground pad114to be brought into contact with the ground pad114.

The above-described EMI shielding structure100has the shielding member140formed by injecting a conductive material having fluidity onto the top surface of the insulation molding member120, thereby shielding the top surface of the insulation molding member120. Hereinafter, a structure for shielding by attaching a shielding member140of a film type to the top surface of the insulation molding member120will be described.

FIG. 7is a cross section view illustrating an EMI shielding structure according to an embodiment of the present disclosure.

FIGS. 8A to 8Fare views illustrating a process of an EMI shielding structure illustrated inFIG. 7according to various embodiments of the present disclosure.

Referring toFIG. 7, an EMI shielding structure100ahas the insulation molding member120formed using the mold10in the same method as in the above-described EMI shielding structure100, and slightly differs from the above-described EMI shielding structure100in that a conductive shielding film150is used and the shielding dam130is formed after the conductive shielding film150is formed.

Hereinafter, a manufacturing process of the EMI shielding structure100aaccording to an embodiment will be described in sequence with reference toFIGS. 8A to 8F.

Referring toFIGS. 8A and 8B, when the PCB110on which the plurality of circuit elements are mounted is loaded into a work position, the mold10is arranged on a position of the PCB110where the insulation molding member120is to be formed as shown inFIG. 8B.

Referring toFIG. 8C, an insulation material having fluidity is injected into the inside11of the mold10, and then the PCB110is put into an oven (not shown) and heated at a predetermined temperature during a predetermined time in order to cure the insulation material. The insulation material cured in the inside11of the mold10becomes the insulation molding member120.

Referring toFIG. 8D, in response to the insulation molding member120being formed, the PCB110is drawn out from the oven and then the mold10is removed from the PCB110.

Referring toFIGS. 8E and 8F, the conductive shielding film150is attached to the top surface of the insulation molding member120. In this case, the size of the conductive shielding film150may be the same as the size of the top surface of the insulation molding member120. This is to realize complete shielding without generating a gap by making the upper end131of the shielding dam130overlap the upper portion of the conductive shielding film150in the post-process of forming the shielding dam130. The size of the conductive shielding film150may be slightly smaller than the size of the top surface of the insulation molding member120. In this case, it is necessary to form the upper end131of the shielding dam130to have a length so as to cover the edge of the conductive shielding film150.

After the conductive shielding film150is attached to the top surface of the insulation molding member120, the shielding dam130for covering the side surface of the insulation molding member120and a part (edge) of the conductive shielding film150is formed by the nozzle216continuously discharging a predetermined amount of conductive material while moving along the side portion of the insulation molding member120.

FIG. 9is a cross section view illustrating an example of a shielding bridge for electrically connecting a shielding dam and a conductive shielding film in an EMI shielding structure ofFIG. 7according to an embodiment of the present disclosure.

Referring toFIG. 9, in an EMI shielding structure100bwhen the size of the conductive shielding film150is smaller than the size of the top surface of the insulation molding member120, the conductive shielding film150does not cover the edge of the top surface of the insulation molding member120, causing a predetermined gap between the upper end131of the shielding dam150and the conductive shielding film150. Therefore, electromagnetic waves may leak through this gap and the shielding efficiency may deteriorate.

In this case, in order fill the gap generated between the upper end131of the shielding dam130and the conductive shielding film150, an edge bridge160may be formed to overlap the upper end131of the shielding dam130and the conductive shielding film150simultaneously. The edge bridge160may be formed of the same conductive material having fluidity as the material of the shielding dam130. The material for forming the edge bridge160has fluidity, such that it can effectively fill the gap generated between the upper end131of the shielding dam130and the conductive shielding film150.

The edge bridge160may electrically contact the shielding dam130and the conductive shielding film150, and can prevent the shielding efficiency from deteriorating by covering the gap generated between the upper end131of the shielding dam130and the conductive shielding film150.

FIGS. 10A and 10Bare schematic views illustrating an example of a process of coating a shielding member on a top surface of the insulation molding member according to various embodiments of the present disclosure.

Referring toFIGS. 10A and 10B, as described above, the conductive shielding film150may be attached to the top surface of the insulation molding member120, but this should not be considered as limiting. The shielding member may be formed on the top surface of the insulation molding member in a coating method.

That is, the process of forming the insulation molding member120using the mold10and forming the shielding dam130on the side portion of the insulation molding member120to form an EMI shielding structure100′ is the same as the above-described process of forming the EMI shielding structure100. After the shielding dam130is formed, as illustrated inFIG. 10B, a shielding member150′ having a predetermined thickness may be formed by spraying an electroconductive material onto the top surface of the insulation molding member120from a spray nozzle190by moving the spray nozzle190along the upper side of the insulation molding member120as illustrated inFIG. 10A. In this case, the amount of material to be sprayed will be enough as long as it does not expose the insulation molding member120.

When the electroconductive material is sprayed, the electroconductive material may be sprayed to cover the upper portion of the shielding dam130and may not generate a gap between the shielding member150′ and the shielding dam130, such that complete shielding can be realized.

In the above-described example, the shielding member150′ is coated after the shielding dam130is formed. However, this should not be considered as limiting. The shielding dam130may be formed after the shielding member150′ is coated on the top surface of the insulation molding member120.

In addition, the shielding member150′ may be coated on the top surface of the insulation molding member120in various methods such as screen printing, ink jetting, or the like instead of the above-described spraying method.

Although not shown in the drawing, after the shielding member150′ is coated on the top surface of the insulation molding member120, the shielding dam130may be formed along the side surface of the insulation molding member120.

In this case, the viscosity of the material forming the shielding member150′ may be greater than or equal to about 10,000 cps so as to prevent the shielding member150from flowing down from the top surface of the insulation molding member120.

FIGS. 11A and 11Bare schematic views illustrating an example of a process of forming a shielding dam and a shielding member in a coating method according to various embodiments of the present disclosure.

Referring toFIGS. 11A and 11B, the process of forming the insulation molding member120using the mold10to form an EMI shielding structure100″ is the same as the process of forming the above-described EMI structure100. After the insulation molding member120is formed, a shielding dam130″ and a shielding member150″ may be formed along with each other as illustrated inFIG. 11Bby spraying an electroconductive material onto the ground pad114and the side surface and the top surface of the insulation molding member120from the spray nozzle190while moving the spray nozzle190along the upper side of the insulation molding member120as illustrated inFIG. 11A. In this case, since the shielding dam130″ may be formed to have the same or similar thickness as or to the thickness of the shielding member150″, the shielding dam130″ may be thinner than the above-described shielding dam130′.

Since the shielding dam130″ and the shielding member150″ are coated on the insulation molding member120in a single process through the spraying method, a processing time can be reduced and a gap is less likely to be generated between the shielding member130″ and the shielding dam150″.

In addition, the shielding dam130″ and the shielding member150″ may be coated on the top surface of the insulation molding member120in various typical methods such as screen printing, ink jetting, or the like instead of the above-described spraying method.

FIGS. 12A and 12Bare views to illustrate a phenomenon which may occur in an insulation molding member when the insulation molding member is formed by applying a sealing member of a rubber material to the lower end of the mold according to various embodiments of the present disclosure.

Referring toFIGS. 12A and 12B, n the process of forming the insulation molding member120on the PCB110, when a lower end15of the mold10is not completely in close contact with the top surface of the PCB110, the insulation material injected into the inside11of the mold10may leak through a gap formed between the lower end15of the mold10and the top surface of the PCB110.

In order to prevent this, a sealing member12made of a rubber material may be connected with the lower end15of the mold10. In this case, since the sealing member12has elasticity, the sealing member120is brought into close contact with the top surface of the PCB110when the mold10is disposed on the PCB110, such that the insulation material injected into the inside11of the mold10can be prevented from leaking to the outside.

However, when the sealing member12is used for long time, the elasticity may be reduced. Therefore, the sealing member120may be deformed to have its opposite sides protrude toward the inside and outside of the mold10, respectively, as illustrated inFIG. 12A. The lower portion of the side surface of the insulation molding member120may be cured with a dented groove120abeing formed by a side portion12aof the sealing member12protruding toward the inside11of the mold10. However, when the side surface of the insulation molding member120is not formed flatways, it may be difficult to form the shielding dam130on the side portion of the insulation molding member120according to a predetermined width to height ratio. This may cause a defect in a product, such as a problem that a part of the conductive material discharged from the nozzle216by a predetermined amount to form the shielding dam130flows into the groove120a,and thus the height of the shielding dam130is reduced,

In addition, when the mold10is removed from the PCB110after the insulation molding member120is cured as illustrated inFIG. 12B, a part of the side surface of the insulation molding member120may be pulled in the direction of removing the mold10by the side portion12aof the sealing member12protruding toward the inside11of the mold10, and a lower portion120bof the insulation molding member120may be separated from the top surface110aof the PCB110.

In order to prevent this problem, the deformed sealing member120should be replaced with a new sealing member120, which causes an inconvenience. In addition, there is a problem that the process should be stopped while the sealing member12is replaced.

The present disclosure can solve the above-described problems which are accompanied by the application of the sealing member12of the rubber material to the mold10using a liquid sealant. The liquid sealant may substitute for the sealing member12. Since the liquid sealant is evaporated after the insulation material injected into the mold10is completely cured, the liquid sealant does not deform the side surface of the insulation molding member120. In addition, when the mold10is removed from the PCB110after the insulation molding member120is completely cured, the liquid sealant has been already evaporated and disappeared. Therefore, the liquid sealant does not influence the insulation molding member120.

The liquid sealant should apply a material which does not blend with the liquid insulation material injected inside the mold10, and should have good wettability (or spreadability) so as to be well coated on a lower end15of the mold10and not to be separated, should have low dispersibility to have a predetermined shape, and should be easily removed by a molding member curing condition or post-processing after the mold is removed, and should not leave a residue. To achieve this, the spreadability and dispersiblity of the liquid sealant on the surface of the PCB should be weaker than on the surface of the mold.

Herein, the spreadability of the liquid sealant refers to a property that can maintain the shape of continuous films formed by coating the liquid sealant on the lower end15of the mold10. The dispersibility refers to a property that maintains the shape of the films in the form of a wall and prevents the shape of the films from being in a thin and wide coated shape. A unit for measuring the spreadability and the dispersibility may be a contact angle (an angle which is formed when the liquid is thermodynamically in equilibrium on the surface of the solid). In addition, the unit for measuring the spreadability and the dispersibility may be a surface tension of the liquid sealant or surface energy of the mold and the PCB.

In addition, the liquid sealant should have a boiling point higher than the curing temperature of the insulation material, such that the liquid sealant can be evaporated at the curing temperature of the insulation material and removed. This is because, when the boiling point of the liquid sealant is close to the curing temperature of the insulation material, bubbles may be generated by boiling while the insulation material is cured and thus there is a high probability that defects are caused. In addition, the liquid sealant should have low steam pressure at room temperature, should have a slower evaporation speed than the curing speed of the insulation molding member120, and should be formed of a material which does not melt or change the insulation molding member.

The liquid sealant satisfying the above-described conditions may apply a single material or a mixed material based on water. When the liquid sealant is a single material, the liquid sealant may be diethylene glycol monobutyl ether, diethylene glycol diethyl ether, ethylene glycol monobutyl ether, triethylene glycol monobutyl ether, diethylene glycol monomethyl ether, ethylene glycol monomethyl ether, triethylene glycol monomethyl ether, or the like.

When the liquid sealant is a mixed material, the liquid sealant may be based on water and may use, as an additive for controlling wettability, methoxy propanol, isopropyl alcohol (IPA), ethanol, methanol, anionic surfactant, cationic surfactant, nonionic surfactant, or the like, and may use, as an additive for controlling volatility, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-butene-1, 4-diol, 2-metyle-2-pentanediol, or the like.

The liquid sealant may be composed by mixing water and the additive for controlling the wettability. In addition, the liquid sealant may be composed by mixing water, the additive for controlling the wettability, and the additive for controlling the volatility. A composition ratio of the liquid sealant may be set variously according to materials.

Hereafter, a process of forming the insulation molding member120using the liquid sealant according to various embodiments will be described.

FIG. 13is a view illustrating a mold which is moved to a tray filled with a liquid sealant to have its lower end coated with the liquid sealant according to an embodiment of the present disclosure.

FIGS. 14A to 14Eare views illustrating a process of manufacturing an EMI shielding structure by evaporating a liquid sealant according to various embodiments of the present disclosure.

Referring toFIG. 13, the mold10may be connected to a robot arm50(or gripped by the robot arm50) and moved to a tray31filled with a liquid sealant30and a molding position for forming the insulation molding member120on the PCB. The mold10may be moved to the upper side of the tray31by the robot arm50prior to being seated on the PCB110and then descend to have the lower end15of the mold10coated with the liquid sealant30.

Referring toFIGS. 14A to 14E, after the mold10is moved to the molding position by the robot arm50with the lower end15being coated with the liquid sealant30as illustrated inFIG. 14A, the mold10is seated on the PCB110as illustrated inFIG. 14B. Since the liquid sealant30closely contacts the surface of the PCB110, the insulation material injected into the inside of the mold10as illustrated inFIG. 14Cdoes not leak between the mold10and the PCB.

In response to the PCB110being set to a predetermined temperature after the insulation material is injected inside the mold10and the PCB110is put into an oven, the insulation material is cured at a first temperature. In response to the temperature in the oven increasing to an evaporation temperature of the liquid sealant, which is higher than the curing temperature of the insulation material, the liquid sealant30is evaporated. Accordingly, the liquid sealant30disappears between the mold10and the PCB110and an empty space is formed as illustrated inFIG. 14D.

In this state, in response to the mold10being removed from the PCB110as illustrated inFIG. 14E, the insulation molding member120may be formed with the flat side surface by the mold10or the sealing member12without being damaged. Although a subsequent process is not illustrated, after the mold10is removed as described above, the shielding dam130may be formed along the side portion of the insulation molding member120by driving the nozzle216(seeFIG. 2E), and then, the shielding member140may be formed by injecting a conductive material onto the top surface of the insulation molding member120(seeFIG. 2F).

After the mold10is removed from the PCB110as illustrated inFIG. 14E, as described above the shielding film150may be attached to the top surface of the insulation molding member120(seeFIG. 8E), and the shielding dam130may be formed along the side portion of the insulation molding member120by driving the nozzle216(seeFIG. 8F).

FIGS. 15A to 15Eare views illustrating a process of manufacturing an EMI shielding structure by removing a liquid sealant through post-processing according to various embodiments of the present disclosure.

Since the processes inFIGS. 15A to 15Care the same as the processes inFIGS. 14A to 14Cin the above-described various embodiments, a description thereof is omitted and subsequent processes will be described.

Referring toFIG. 15D, the liquid sealant30may be formed of a material which is not evaporated in the process of curing the insulation mold member120in the oven.

Referring toFIG. 15E, after the mold10is removed from the PCB110, the liquid sealant30may be completely removed from the PCB110by scraping the liquid sealant30using a predetermined peeling tool.

In this case, the liquid sealant30remaining on the PCB110may be removed by heating at a high temperature without using the peeling tool. Specifically, the liquid sealant30remaining on the PCB110may be removed by heating in a temperature range between the curing temperature of the insulation molding member120and the boiling point of the liquid sealant30or a temperature range between the curing temperature of the insulation molding member120and a heat resistance temperature of the insulation molding member120. In this case, a processing condition may be setting a change in temperature of a curing furnace (not shown) in two steps, the curing temperature of the insulation molding member120and a temperature higher than the curing temperature, for evaporating and removing the liquid sealant30.

FIGS. 16A to 16Fare views illustrating a process of manufacturing an EMI shielding structure to explain an example by injecting a liquid sealant between a mold and a PCB after the mold is set according to various embodiments of the present disclosure.

Referring toFIGS. 16A to 16F, the mold10is moved to a molding position as illustrated inFIG. 16Bwithout having the lower end15coated with the liquid sealant130as illustrated inFIG. 16A. In this case, the mold10may be supported by the robot arm50and spaced from the PCB110over the PCB110by a predetermined distance. The liquid sealant130is injected into a space between the mold10and the PCB110as illustrated inFIG. 16C. In response to the liquid sealant30being completely injected, an insulation material is injected into the inside of the mold10as illustratedFIG. 16D. In this case, the insulation material does not leak between the mold10and the PCB due to the liquid sealant30.

In response to the PCB110being set to a predetermined temperature after the insulation material is injected inside the mold10and the PCB110is put into an oven, the insulation material is cured at the predetermined temperature, and the liquid sealant30is gradually evaporated at the curing temperature. Alternatively, in response to the temperature in the oven increasing to an evaporation temperature of the liquid sealant, which is higher than the curing temperature of the insulation material, the liquid sealant30is evaporated. Accordingly, the liquid sealant30disappears between the mold10and the PCB110and an empty space is formed as illustrated inFIG. 16E.

In this state, in response to the mold10being removed from the PCB110as illustrated inFIG. 16F, the insulation molding member120may be formed with the flat side surface by the mold10or the sealing member12without being damaged.

FIGS. 17A to 17Fare views illustrating a process of manufacturing an EMI shielding structure by injecting a liquid sealant between a mold and a PCB after the mold is set and removing the liquid sealant through post-processing according to various embodiments of the present disclosure.

Since the processes inFIGS. 17A to 17Dare the same as the processes inFIGS. 16A to 16Din the above-described various embodiments, a description thereof is omitted and subsequent processes will be described.

Referring toFIG. 17E, the liquid sealant30may be formed of a material which is not evaporated in the process of curing the insulation mold member120in the oven.

Referring toFIG. 17F, after the mold10is removed from the PCB110, the liquid sealant30may be completely removed from the PCB110by scraping the liquid sealant30using a predetermined peeling tool.

FIGS. 18A to 18Care views illustrating a process of manufacturing an EMI shielding structure by controlling the height of an insulation molding member differently by controlling an amount of insulation material to be injected into a mold when a plurality of shielding structures are formed according to various embodiments of the present disclosure.

Referring toFIG. 18A, three molds10-1,10-2, and10-3are arranged on the PCB110. In this case, the circuit elements mounted in shielding areas may have different heights, and a different amount of insulation material is injected into each mold10-1,10-2, and10-3with reference to the maximum height of the circuit elements mounted in each shielding area. That is, the amount of insulation material to be injected into the mold10-1disposed on the left side is larger than the amount of insulation material to be injected into the mold10-2disposed on the center, but is smaller than the amount of insulation material to be injected into the mold10-3disposed on the right side. In this case, the three molds10-1,10-2, and10-3may be integrally formed with one another and may be moved by a single robot arm50simultaneously.

In response to the different amount of insulation material being completely injected into each mold10-1,10-2, and10-3, the PCB110is put into an oven and insulation molding members120-1,120-2, and120-3are formed by curing the insulation material. In this process, the liquid sealant30is evaporated, but, when the liquid sealant30is formed of a material which is not evaporated, the liquid sealant30may be removed from the PCB110using a tool after the molds10-1,10-2, and10-3are removed.

Referring toFIGS. 18B and 18C, in response to the insulation molding members120-1,120-2, and120-3of different heights being formed, shielding dams130-1,130-2, and130-3may be formed along the side portions of the insulation molding members120-1,120-2, and120-3. In this case, the shielding dams130-1,130-2, and130-3may be formed to have different heights according to the heights of the insulation molding members120-1,120-2, and120-3. The shielding dams130-1,130-2, and130-3are formed using nozzles having guide portions of different lengths according to the lengths of the shielding dams130-1,130-2, and130-3.

After the shielding dams130-1,130-2, and130-3are formed, shielding members140-1,140-2, and140-3may be formed by filling the top surfaces of the insulation molding members120-1,120-2, and120-3with a conductive material. According to the present various embodiments, there is an advantage that the plurality of shielding structures are manufactured simultaneously.

In the above-described various embodiments, the insulation molding member is used using the mold and the shielding dam and the shielding member are formed after the mold is removed. Hereinafter, a process of forming a part of the shielding structure without removing the mold according to various embodiments will be described.

FIGS. 19A to 20Eare views illustrating a process of manufacturing an EMI shielding structure by including a mold in the EMI shielding structure without removing the mold according to various embodiments of the present disclosure.

Referring toFIG. 19A, a sealant30′ is connected to the lower end of the mold10. Since the sealant30′ is not removed from the mold10, the sealant30′ does not have to be a liquid material which can be evaporated and may be a solid sealant having elasticity.

Referring toFIG. 19B, the mold10is moved to a molding position by the robot arm50and then seated on the PCB110. The sealant30′ may be brought into close contact with the surface of the PCB110due to the elasticity.

Referring toFIG. 19C, in the state in which the sealant30′ is in close contact with the PCB110, the insulation molding member120is formed by injecting an insulation material into the inside of the mold10. In this case, the liquid insulation material has fluidity but does not leak between the mold10and the PCB110due to the sealant30′. The insulation material injected into the mold10is filled up to a top surface13aof the mold10by adjusting the amount of injection, and is cured.

Referring toFIG. 19D, the shielding dam130is formed along the side portion of the insulation molding member120by driving the nozzle216(seeFIG. 2E). In this case, the upper end131of the shielding dam130may be formed to cover the top surface13aof the mold10.

Referring toFIG. 19E, the shielding member140is formed by discharging an electroconductive material to the top surface of the mold10and the top surface of the insulation molding member120, and then is cured. In this case, the electroconductive material discharged from the nozzle is discharged by a predetermined amount such that the electroconductive material does not flow over the upper end131of the shielding dam130.

As described above, the mold10may be used as a single component forming the shielding structure without being removed in the process. In this case, the mold10may be formed of an electroconductive material or an insulation material.

FIGS. 20A to 20Eillustrate embodiments in which a shielding structure is formed without removing a mold according to the various embodiments ofFIGS. 19A to 19E.

Referring toFIGS. 20A and 20B, the mold10having the sealant30′ connected to the lower end thereof as illustrated inFIG. 20Ais moved to a molding position by the robot arm50and then seated on the PCB110as illustrated inFIG. 20B.

In this state, the insulation molding member120is formed by injecting an insulation material into the inside of the mold10and curing the insulation material.

Referring toFIG. 20C to 20E, an electroconductive shielding film150is attached to the top surface of the mold10and the top surface of the insulation molding member120as shown inFIG. 20D, and then the shielding dam130is formed along the side portion of the insulation molding member120by driving the nozzle216as shown inFIG. 20E. In this case, the upper end131of the shielding dam130may cover the edge of the top surface of the electroconductive shielding film150and may be electrically connected with the electroconductive shielding film150.

FIG. 21is a perspective view illustrating a mobile phone terminal to which an EMI shielding structure according to an embodiment of the present disclosure.

FIG. 22is a perspective view illustrating a smart watch having an EMI shielding structure according to an embodiment of the present disclosure.

Referring toFIGS. 21 and 22, the EMI shielding structures having the above-described various structures can be applied to various electronic devices. That is, the EMI shielding structure may be installed in a smart phone310as illustrated inFIG. 21or may be installed in a smart watch320as illustrated inFIG. 22.