KR102517689B1 - Shield device of electromagnetic interference and method of fabricating the same - Google Patents

Abstract

Embodiments relate to an electromagnetic wave shielding device including a molding member for blocking electromagnetic waves and a method of manufacturing the same, and the electromagnetic wave shielding device according to an embodiment includes a molding member surrounding at least one electronic element mounted on a substrate; and a shielding member including a first conductive film, a second conductive film, a third conductive film, and a fourth conductive film sequentially stacked to surround the molding member, wherein the first conductive film has a thickness greater than that of the second conductive film. thin.

Description

Electromagnetic wave shielding device and manufacturing method thereof

The embodiment relates to an electromagnetic wave shielding device.

Mobile communication terminals such as mobile phones, PDAs (Personal Digital Assistants), smart phones, communication equipment, various media players, etc., which are widely used today, have a number of electronic elements built into them to function, and electronic elements are printed circuit boards (Printed Circuit Boards; It is common to configure an integrated module on a PCB).

In particular, a Radio Frequency (RF) integrated module is exposed to electromagnetic wave interference, and abnormal functions are induced in electronic elements constituting the integrated module due to the electromagnetic wave interference. Such electromagnetic interference is called EMI (Electromagnetic Interference), and is unnecessarily radiated (Radiated Emission; RE) or conducted (Conducted Emission; CE) from an electronic device to affect the function of an adjacent electronic device. As a result, the circuit function deteriorates and malfunction of the device occurs.

In general, CE (Conducted Emission) is electromagnetic noise generated mainly below 30 MHz, and is transmitted through a medium such as a signal line or power line. Further, RE (Radiated Emission) is electromagnetic noise mainly generated at 30 MHz or higher, and is radiated and transmitted into the air and has a wider radiation range than CE.

In order to solve the above problems, a metal can for blocking electromagnetic waves may be used. However, the metal can individually covers a plurality of electronic devices mounted on a substrate, and since the height of the metal can, the material of the metal can, and the thickness of the metal can must be considered, it is difficult to apply it to various modules. Moreover, it is difficult to completely block electromagnetic waves due to the gap between the metal can and the printed circuit board.

Embodiments provide an electromagnetic wave shielding device including a molding member for blocking electromagnetic waves and a manufacturing method thereof.

An electromagnetic wave shielding device according to an embodiment includes a molding member surrounding at least one electronic element mounted on a substrate; and a shielding member including a first conductive film, a second conductive film, a third conductive film, and a fourth conductive film sequentially stacked to surround the molding member, wherein the first conductive film has a thickness greater than that of the second conductive film. thin.

The electromagnetic wave shielding device and the manufacturing method of the embodiment have the following effects.

First, since the first conductive film directly in contact with the molding member of the electromagnetic wave shielding device is thinner than the second conductive film serving as a seed layer of the third conductive film, the adhesion between the shielding member and the molding member is improved.

Second, the shielding member is formed to cover up to at least one side of the substrate, so that the electronic device mounted on the substrate is completely sealed by the substrate, the molding member, and the shielding member. Therefore, the electromagnetic wave shielding function can be improved.

1 is a cross-sectional view of an electromagnetic wave shielding device according to an embodiment of the present invention.
2 is a photograph of blisters occurring on a molding member.
3 is a cross-sectional view of an electromagnetic wave shielding device according to another embodiment of the present invention.
4 is a graph showing the electromagnetic wave shielding of the present invention.
5A to 5F are cross-sectional views illustrating a manufacturing method of an electromagnetic wave shielding device according to an embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated and described in the drawings. However, this is not intended to limit the embodiments of the present invention to specific embodiments, and should be understood to include all changes, equivalents, or substitutes included in the spirit and technical scope of the embodiments.

Terms including ordinal numbers, such as first and second, may be used to describe various components, but the components are not limited by the terms. The terms are used for the purpose of distinguishing one component from another. For example, a second element may be named a first element without departing from the scope of rights of an embodiment, and similarly, the first element may also be named a second element. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when a component is referred to as “directly connected” or “directly connected” to another component, it should be understood that no other component exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the embodiments of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

In the description of the embodiment, in the case where one component is described as being formed “on or under” another component, the upper (above) or lower (below) (on or under) includes both formed by directly contacting two components or by placing one or more other components between the two components (indirectly). In addition, when expressed as "on or under", it may include not only an upward direction but also a downward direction based on one component.

Hereinafter, the embodiment will be described in detail with reference to the accompanying drawings, but the same or corresponding components regardless of reference numerals are given the same reference numerals, and overlapping descriptions thereof will be omitted.

Hereinafter, an electromagnetic wave shielding device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of an electromagnetic wave shielding device according to an embodiment of the present invention.

As shown in FIG. 1 , the electromagnetic wave shielding device according to an exemplary embodiment of the present invention includes a molding member 15 and a first conductive film 20a, a second conductive film 20b, and a third conductive film sequentially stacked to surround the molding member 15. 20c) and the fourth conductive film 20d, the electromagnetic wave shielding device may be disposed to completely enclose the electronic elements 10a and 10b mounted on the substrate 10. In particular, the electromagnetic wave shielding device has a structure that surrounds a plurality of electronic elements 10a and 10b at once.

The substrate 10 may be selected from printed circuit boards (PCBs), low temperature co-fired ceramics (LTCCs), etc., on which electronic circuits including wires are formed, but is not limited thereto. LTCC is formed by using a method of co-firing ceramic and metal at a temperature of 800 ° C to 1000 ° C, and silver, It can be formed by printing a conductive paste such as copper. The LTCC as described above is formed with passive elements such as capacitors, resistors, and inductors, enabling high integration and light, thin, and small size.

The electronic elements 10a and 10b mounted on the substrate 10 as described above may be driven by being connected to wiring formed on the substrate 10 .

A plurality of electronic devices 10a and 10b are mounted on the board 10 to form an integrated module, and in particular, a radio frequency (RF) integrated module used in a tracking system device, a voltage controlled oscillator, a transceiver for optical communication, and the like. are exposed to severe radio interference. Such radio wave interference generates electromagnetic interference (EMI) of the electronic devices 10a and 10b constituting the integrated module. In addition, as a result, the circuit function of the substrate 10 is deteriorated or the malfunction of the device occurs, resulting in a decrease in reliability.

Therefore, electromagnetic interference can be prevented by covering the electronic elements 10a and 10b with the electromagnetic wave shielding device of the present invention. The electromagnetic wave shielding device may include a molding member 15 and a shielding member 20 .

The molding member 15 may protect the electronic devices 10a and 10b from external impact and prevent a short circuit in a bonding area where the electronic devices 10a and 10b and the substrate 1 are fixed. The molding member 15 as described above may be formed to completely enclose the plurality of electronic devices 10a and 10b. The molding member 15 may be formed on the entire surface of the substrate 10 excluding the antenna.

The molding member 15 may include a synthetic resin material such as epoxy or silicone. For example, the molding member 15 may be an epoxy molding compound (EMC). The material of the molding member 15 is not limited thereto. The molding member 15 may be formed by a Dam & Fill molding method, a transfer molding method, or the like.

The upper surface of the molding member 15 includes the concavo-convex pattern 15a, so that bonding force and fixing force between the shield member 20 and the molding member 15 may be improved. The concavo-convex pattern 15a may be formed through surface treatment of the molding member 15 using an ion beam, plasma, or the like, but is not limited thereto.

It is preferable that the roughness average (Ra) of the concavo-convex pattern 15a is 5 μm or less. This is because the molding member 15 may partially expose the electronic devices 10a and 10b if the average roughness of the concavo-convex pattern 15a is too large. To prevent this, the molding member 15 must be very thick. That is, the thickness of the electromagnetic wave shielding device increases, making it difficult to reduce the thickness of the electromagnetic wave shielding device.

The shielding member 20 includes first, second, third, and fourth conductive films 20a, 20b, 20c, and 20d, and the first, second, third, and fourth conductive films 20a, 20b, 20c and 20d) may be structures surrounding the molding member 15 in turn. In this case, the first and second conductive layers 20a and 20b may be formed along the uneven pattern 15a.

The first conductive film 20a is used to improve bonding strength between the shield member 20 and the molding member 15, and the first conductive film 20a and the shield member 20 are in direct contact with each other. The first conductive layer 20a may be formed by a sputtering method, and may be formed using a cylindrical sputtering device so as to be formed on the side surface of the molding member 15 . At this time, the thickness d1 of the first conductive film 20a is smaller than the thickness d2 of the second conductive film 20b.

The second conductive layer 20b may be formed using a sputtering method, an electroless plating method, or the like. When the second conductive film 20b is formed by a sputtering method, the second conductive film 20b can be formed on the entire surface of the first conductive film 20a by using a cylindrical sputtering device as described above. .

In general, the second conductive layer 20b functions as a seed layer for forming the third conductive layer 20c. Therefore, in order to form the third conductive film 20c to a sufficient thickness on the second conductive film 20b and at the same time prevent the film characteristics of the third conductive film 20c from deteriorating, the second conductive film 20b There is a limit to reducing the thickness (d2) of.

However, when the second conductive layer 20b is in direct contact with the molding member 15, the adhesion force of the molding member 15 may decrease due to the thickness d2 of the second conductive layer 20b. In this case, during a reflow process for electrically connecting the electronic elements 10a and 10b and the wiring (not shown) of the substrate 10, the interface between the second conductive film 20b and the molding member 15 This lifting problem can occur.

2 is a photograph of blisters occurring on a molding member.

During the reflow process at about 260°, the interface between the molding member 15 and the shielding member 20 is lifted, and blisters may occur on the surface of the molding member 15 as shown in FIG. 2 . And, accordingly, the electromagnetic wave shielding function may be deteriorated.

On the other hand, in the present invention, the first conductive film 20a having a thickness d1 smaller than the thickness d2 of the second conductive film 20b is disposed between the molding member 15 and the second conductive film 20b. , Adhesion between the shield member 20 and the molding member 15 may be improved. Furthermore, the first conductive layer 20a having a thin thickness d1 may be uniformly formed along the concave-convex pattern 15a of the molding member 15 . Accordingly, an area in which the shield member 20 and the molding member 15 come into close contact with each other through the concave-convex pattern 15a increases, so that bonding strength can be further improved.

Moreover, since the first conductive layer 20a functions as a seed layer of the second conductive layer 20b, anchoring energy of the second conductive layer 20b can be improved. Thus, the third conductive layer 20c may be uniformly formed on the second conductive layer 20b.

The first conductive layer 20a may include nickel (Ni), nickel chromium (NiCr), or the like, and the second conductive layer 20b may include copper (Cu). At this time, the material of the first and second conductive films 20a and 20b is not limited thereto. In addition, when the first conductive layer 20a is formed of nickel (Ni) or nickel chromium (NiCr) as described above, the thickness d1 of the first conductive layer 20a may be 0.1 μm to 0.5 μm, When the second conductive layer 20b is formed of copper, the thickness d2 of the second conductive layer 20b may be 0.6 μm to 1 μm.

The third conductive layer 20c has a thicker thickness than the first and second conductive layers 20a and 20b, and can substantially block electromagnetic waves generated from the electronic elements 10a and 10b. The third conductive layer 20c may be formed on the surface of the second conductive layer 20b using an electroplating method, and the third conductive layer 20c may include copper (Cu).

The third conductive layer 20c may be formed to cover the concavo-convex pattern 15a of the molding member 15 so that the surface of the fourth conductive layer 20d, which will be described later, is flat. To this end, the third conductive layer 20c may have a thicker thickness than the first and second conductive layers 20a and 20b.

For example, if the thickness of the third conductive film 20c is too thin, the electromagnetic wave shielding function of the third conductive film 20c is degraded, and if the thickness of the third conductive film 20c is too thick, the process time is reduced. As the size of the module increases, the size of the module may increase as the volume of the electromagnetic wave shielding device increases. Accordingly, the thickness of the third conductive layer 20c may be 2.5 μm to 2.8 μm.

The fourth conductive layer 20d may be formed using an electro plating method. The fourth conductive layer 20d is formed on the outermost surface of the shielding member 20 to prevent discoloration or oxidation of the shielding member 20 . To this end, the fourth conductive layer 20d may be formed of a stable metal having low reactivity. For example, the fourth conductive layer 20d may include nickel (Ni) having high corrosion resistance. . The fourth conductive layer 20d may have a thickness of 0.6 μm to 1 μm, but is not limited thereto.

In the electromagnetic wave shielding device according to the embodiment of the present invention as described above, adhesion between the molding member 15 and the shielding member 20 may be improved. At this time, the electromagnetic wave shielding device is integrally formed to surround the plurality of electronic elements 10a and 10b, and the molding member 15 and the shielding member 20 are formed with an antenna for radiating radio waves of the electronic elements 10a and 10b. It may be formed to cover the entire surface of the substrate 10 except for the transmission unit. Furthermore, the shielding member 20 exposes the transmission unit and is formed to cover up to at least one side surface of the board 10, and the electronic devices 10a and 10b are connected to the board 10, the molding member 15, and the shielding member 20. ) may be a completely sealed structure.

3 is a cross-sectional view of an electromagnetic wave shielding device according to another embodiment of the present invention.

As shown in FIG. 3 , the concave-convex pattern 15a may be formed not only on the top surface of the molding member 15 but also on the side surface of the molding member 15 . In this case, the upper and side surfaces of the first and second conductive films 20a and 20b are also formed along the concave-convex pattern 15a, so that the area where the molding member 15 and the shielding member 20 come into close contact is further increased. The bonding strength can be further improved.

4 is a graph showing the electromagnetic wave shielding of the present invention.

As shown in FIG. 4 , when the module does not include an electromagnetic wave shielding device, the module generates four peaks including the original signal. However, when an electromagnetic wave shielding device is provided, the module may generate only an original signal (one peak). And, one peak may be transmitted through the antenna exposed by the electromagnetic wave shielding device as described above.

Hereinafter, a method of manufacturing an electromagnetic wave shielding device according to an embodiment of the present invention will be described in detail.

5A to 5F are cross-sectional views illustrating a manufacturing method of an electromagnetic wave shielding device according to an embodiment of the present invention.

As shown in FIG. 5A , a molding member 15 is formed on the substrate 10 to surround the electronic devices 10a and 10b disposed on the substrate 10 . Although not shown. The molding member 15 may be formed on the entire surface of the substrate 10 except for the antenna of the module. Then, as shown in FIG. 5B , a concave-convex pattern 15a is formed on the surface of the molding member 15 by using an ion beam and plasma. Although not shown, the concave-convex pattern 15a may also be formed on the side surface of the molding member 15 .

As shown in FIG. 5C , the first conductive layer 20a is formed to surround the molding member 15 . The first conductive layer 20a may be formed by a sputtering method, and may be formed using a cylindrical sputtering device so as to be formed on the side surface of the molding member 15 . In this case, the first conductive layer 20a may be formed along the uneven pattern 15a.

As shown in FIG. 5D, a second conductive film 20b is formed on the surface of the first conductive film 20a. The second conductive film 20b may be formed by a sputtering method, an electroless plating method, or the like. In the case of using the sputtering method, the second conductive film 20b is formed using a cylindrical sputtering device as described above. It can be. The second conductive layer 20b may also be formed along the concavo-convex pattern 15a. At this time, the thickness d2 of the second conductive film 20b is greater than the thickness d1 of the first conductive film 20a.

For example, the first conductive layer 20a may include nickel (Ni) or nickel chromium (NiCr), and the second conductive layer 20b may include copper (Cu). At this time, the material of the first and second conductive films 20a and 20b is not limited thereto. In addition, when the first conductive layer 20a is formed of nickel (Ni) or nickel chromium (NiCr) as described above, the thickness d1 of the first conductive layer 20a may be 0.1 μm to 0.5 μm, When the second conductive layer 20b is formed of copper, the thickness d2 of the second conductive layer 20b may be 0.6 μm to 1 μm.

As shown in FIG. 5E, a third conductive layer 20c is formed to surround the second conductive layer 20b. The third conductive layer 20c substantially blocks electromagnetic waves generated from the electronic devices 10a and 10b and may be formed using an electroplating method.

And, as shown in FIG. 5F, a fourth conductive film 20d is formed to surround the third conductive film 20c. The fourth conductive layer 20d may be formed using an electro plating method. The fourth conductive layer 20d is formed on the outermost surface of the shielding member 20 to prevent discoloration or oxidation of the shielding member 20 .

As described above, the shield member 20 including the first, second, third, and fourth conductive films 20a, 20b, 20c, and 20d exposes the antenna as described above, and at least one part of the substrate 10 The electronic devices 10a and 10b may be completely sealed by the substrate 10 , the molding member 15 , and the shielding member 20 .

Therefore, even if the module including the electromagnetic wave shielding device of the embodiment of the present invention is applied to a high-power product, electromagnetic wave interference can be efficiently prevented, and the adhesion between the shield member 20 and the molding member 15 is improved, so that the shield member 20 It is possible to prevent occurrence of blisters at the interface between the mold member 15 and the molding member 15 .

The present invention described above is not limited to the above-described embodiments and accompanying drawings, and various substitutions, modifications, and changes are possible within a range that does not depart from the technical spirit of the embodiments. It will be clear to those who have knowledge.

10: substrate 10a, 10b: electronic element
15: molding member 15a: concave-convex pattern
20: shielding member 20a: first conductive film
20b: second conductive film 20c: third conductive film
20d: 4th conductive film

Claims (7)

a molding member surrounding at least one electronic device mounted on a substrate and including a first concavo-convex pattern formed on at least one surface;
a first conductive film surrounding the molding member, containing nickel or nickel chromium, and having a thickness of 0.1 μm to 0.5 μm;
a second conductive layer surrounding the first conductive layer, including copper, and having a thickness of 0.6 μm to 1 μm;
a third conductive layer surrounding the second conductive layer, including copper, and having a thickness of 2.5 μm to 2.8 μm; and
and a fourth conductive film surrounding the third conductive film and containing nickel and having a thickness of 0.6 μm to 1 μm. delete delete According to claim 1,
The molding member surrounds all of the at least one electronic device,
The electromagnetic wave shielding device of claim 1 , wherein the first conductive film or the second conductive film surrounds at least one side surface of the substrate. delete According to claim 1,
The first conductive film and the second conductive film each include a second concavo-convex pattern formed according to the first concavo-convex pattern,
The third conductive film is an electromagnetic wave shielding device formed of a planarization film obtained by flattening the second concavo-convex pattern.

delete

Images