TWI696259B - Electromagnetic wave shilding element and transmisson line assembly using the same - Google Patents

Abstract

An electromagnetic wave shielding element, and a transmission line assembly using the same are provided. The electromagnetic wave shielding element can be applied in the transmission line assembly for shielding the electromagnetic wave noise. The electromagnetic wave shielding element at least includes a quantum well structure. The quantum well structure includes two barrier layers and a carrier confinement layer interposed between the two barrier layers. At least one of the barrier layers is a composite material layer, and the composite material layer includes a matrix and a plurality of quantum dots embedded in the matrix.

Description

Electromagnetic wave shield and transmission line assembly using the same

The invention relates to an electromagnetic wave shield and a transmission line assembly using the same, in particular to an electromagnetic wave shield which can effectively suppress crosstalk during signal transmission and a transmission line assembly using the same.

In recent years, with the development of electronic products toward light, thin and short, the demand for high-frequency and high-speed signal transmission, between various chips (such as wireless communication chips) in electronic products, and inside cables used to transmit high-frequency signals The configuration of the transmission wires is also getting denser.

According to this, the electromagnetic waves generated by the wafer easily cause electromagnetic interference to other wafers. Similarly, when high-frequency and low-frequency signals are transmitted through a transmission line inside a cable, two adjacent transmission lines are likely to crosstalk due to electromagnetic wave coupling or diffusion. In the prior art methods, the metal shielding layer is usually covered on the outside of the chip or on the cable used to transmit signals to prevent electromagnetic interference.

However, the metal shielding layer cannot absorb high-frequency electromagnetic waves with a frequency above 1 GHz, and may still interfere with signals transmitted by other transmission lines. Accordingly, how to shield high-frequency electromagnetic waves to reduce noise in signal transmission is still the direction of efforts by those skilled in the art.

The technical problem to be solved by the present invention is to provide an electromagnetic wave shield to reduce the crosstalk caused by electromagnetic wave noise on the signal transmission line.

In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide an electromagnetic wave shield, which includes a quantum well structure. The quantum well structure includes two barrier layers and at least one carrier confinement layer between the two barrier layers. At least one of the two barrier layers is a composite material layer, and the composite material layer includes a substrate and a plurality of quantum dots embedded in the substrate.

In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a transmission line assembly including a wire set and an electromagnetic wave shield. The wire set includes at least a wire and an insulating layer covering the wire. The electromagnetic wave shield is arranged on the wire group and includes a quantum well structure. The quantum well structure includes two barrier layers and at least one carrier confinement layer between the two barrier layers. At least one of the two barrier layers is a composite material layer, and the composite material layer includes a substrate and a plurality of quantum dots embedded in the substrate.

One of the beneficial effects of the present invention is that, in the electromagnetic wave shield provided by the present invention and the transmission line assembly using the same, at least one of “the electromagnetic wave shield includes a quantum well structure” and “two barrier layers are The composite material layer, and the composite material layer includes a base material and a plurality of quantum dots embedded in the base material. The technical solution can absorb high-frequency and low-frequency electromagnetic noise to suppress electromagnetic interference.

In order to further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and explanation only, and are not intended to limit the present invention.

1. 1’: Electromagnetic wave shield

S1: First side

S2: Second side

11: Quantum well structure

110, 110’, 110”: barrier layer

M1, M2: substrate

QD, QD1, QD2: quantum dots

Eg ₁ , Eg ₁ ': barrier gap energy gap width

110Ec, 110’Ec: barrier layer conductive tape

110Ev, 110’Ev: barrier price band

T1: Barrier layer thickness

111: Carrier localization layer

Eg ₂ : Carrier limited layer energy gap width

111Ec: carrier confinement layer conductive tape

111Ev: Carrier-limited price band

△Ec: Energy gap difference

T2: Carrier limited layer thickness

12, 12’: Electronic transmission structure

120: first floor

121, 121’: Second floor

121a: conductive part

121b: Insulated part

EM: electromagnetic wave

P1~P3: Transmission line components

2: wire set

21: Wire

22: Insulation

3: cladding

FIG. 1 shows a schematic diagram of an electromagnetic wave shield of the first embodiment of the present invention.

2 is a schematic diagram of the energy band structure of the quantum well structure according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram of an electromagnetic wave shield according to a second embodiment of the invention.

4 is a schematic diagram of an electromagnetic wave shield of a third embodiment of the invention.

5 is a schematic diagram of an electronic transmission structure according to another embodiment of the invention.

6 is a schematic diagram of an electronic transmission structure according to yet another embodiment of the invention.

7 is a schematic diagram of an electromagnetic wave shield of a fourth embodiment of the invention.

8 is a schematic cross-sectional view of a transmission line assembly according to a first embodiment of the invention.

9 is a schematic cross-sectional view of a transmission line assembly according to a second embodiment of the invention.

10 is a schematic cross-sectional view of a transmission line assembly according to a third embodiment of the invention.

The following is a description of the implementation of the "electromagnetic wave shield and transmission line assembly using the same" disclosed by the present invention through specific specific examples. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments. Various details in this specification can also be based on different viewpoints and applications, and various modifications and changes can be made without departing from the concept of the present invention. In addition, the drawings of the present invention are merely schematic illustrations, and are not drawn according to actual sizes, and are declared in advance. The following embodiments will further describe the related technical content of the present invention in detail, but the disclosed content is not intended to limit the protection scope of the present invention.

It should be understood that although terms such as “first”, “second”, and “third” may be used herein to describe various elements or signals, these elements or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" as used herein may include any combination of any one or more of the associated listed items, depending on the actual situation.

[First embodiment]

In the embodiment of the present invention, the electromagnetic wave shield 1 has at least a quantum well structure 11 to shield low-frequency and high-frequency electromagnetic interference. Please refer to Figure 1. FIG. 1 shows a schematic diagram of an electromagnetic wave shield of the first embodiment of the present invention.

The electromagnetic wave shield 1 includes at least a quantum well structure 11 and has a first side S1 and a second side S2 opposite to the first side S1.

Please refer to FIG. 1 and FIG. 2 together. FIG. 2 is a schematic diagram of the energy band structure of the quantum well structure according to the first embodiment of the present invention. The quantum well structure 11 includes at least two barrier layers 110, 110' and at least one carrier confinement layer 111 between the two barrier layers 110, 110'. In other embodiments, the quantum well structure 11 may also include multiple barrier layers 110, 110' and multiple carrier confinement layers 111, which is not limited in the present invention.

Please refer to FIG. 2. The energy gap widths Eg ₁ and Eg ₁ ′ of each barrier layer 110 and 110 ′ are greater than the energy gap width Eg _{2 of} each carrier confinement layer 111. In other words, the material of the barrier layers 110 and 110' is a wide band gap material, and the material of the carrier confinement layer 111 is a narrow band gap material.

In addition, the conductive bands 110Ec and 110'Ec of each barrier layer 110 and 110' form an energy gap difference ΔEc (or energy barrier) with the conductive band 111Ec of the adjacent carrier confinement layer 111. In one embodiment, the energy gap difference ΔEc formed between the conductive tapes 110Ec, 110'Ec of each barrier layer 110 and the conductive tape 110Ec of each carrier confinement layer 111 is at least 0.2 eV. As shown in FIG. 2, the energy barrier structure of the two barrier layers 110, 110' and the carrier confinement layer 111 sandwiched between them forms a quantum well.

It is worth noting that the material and thickness of the barrier layers 110, 110', and the material and thickness of the carrier confinement layer 111 are related to the electromagnetic wave band that the quantum well structure 11 can absorb. According to this, by selecting specific materials as the barrier layer 110 and the carrier confinement layer 111, and making the barrier layer 110 and the carrier confinement layer 111 have specific thicknesses, respectively, the quantum well structure 11 can be compared with electromagnetic waves in a specific wavelength band Good absorption effect. In an embodiment, the material of the carrier confinement layer 111 may be a semiconductor, Metal, alloy, or any combination thereof.

In the embodiment of the present invention, at least one of the two barrier layers 110, 110' is a composite material layer. In this embodiment, the barrier layer 110 is a composite material layer, and includes a substrate M1 and a plurality of quantum dots QD embedded in the substrate M1. In addition, the material of the other barrier layer 110' is the same as the material of the substrate M1, but the invention is not limited thereto. In other embodiments, the material of the other barrier layer 110' may also be different from the material of the substrate M1.

The energy gap width of the material of the quantum dot QD will be greater than the energy gap width of the substrate M1. For example, the material of the substrate M1 may be oxide, nitride, oxynitride, or any combination thereof. The material of the quantum dot QD is one of the group consisting of oxide, carbide, nitride, oxynitride, p-type semiconductor, and any combination thereof.

Referring to FIG. 2, the quantum dot QD doped in the substrate M1 can generate multiple defect trap levels. Therefore, compared to the other barrier layer 110 ′ which is not doped with quantum dots QD, the quantum dot QD increases the number of holes in the barrier layer 110 and increases the probability of capturing electrons. In addition, compared with the other barrier layer 110', since the barrier layer 110 has more holes, the valence band 110Ev of the barrier layer 110 will also shift downward, so that the barrier layer 110 The energy gap width Eg _{1 is} greater than the energy gap width Eg ₁ ′ of the barrier layer 110 ′. In an embodiment, the radius of the quantum dot QD is from 1.8 nm to 5 nm, and the volume percentage of the quantum dot QD is between 6 and 15%.

According to this, when the electromagnetic wave EM enters the quantum well structure 11, the barrier layer 110 absorbs the electromagnetic wave, so that the electrons in the valence band 110Ev of the barrier layer 110 are excited to the conductive band 110Ec. Since the quantum dot QD can increase the number of holes in the barrier layer 110, a part of the electrons excited to the conductive band 110Ec can easily recombine with the holes in the barrier layer 110. In other words, the barrier layer 110 itself can be used as a wave absorbing material, which can enhance the effect of electromagnetic wave absorption.

Another part of the electrons that do not recombine with the holes in the barrier layer 110 will enter the quantum well and be confined within the quantum well. Therefore, the electromagnetic wave EM entering the quantum well structure 11 will be absorbed, but difficult To penetrate or reflect to the outside of the quantum well structure 11.

In addition, the barrier layer 110 having quantum dots QD may have a large energy gap width Eg ₁ . According to this, the barrier layer 110 can further assist the quantum well structure 11 to absorb electromagnetic waves in a higher frequency band. In one embodiment, the quantum well structure 11 can be used to absorb at least one electromagnetic wave with a frequency ranging from 1 GHz to 300 GHz.

In one embodiment, the base material M1 of the barrier layer 110 is a non-stoichiometric compound and has multiple anion vacancies. Furthermore, when the substrate M1 is an oxide, a nitride, or an oxynitride, the substrate M1 may have oxygen vacancies or nitrogen vacancies. In this way, the number of holes in the barrier layer 110 can also be increased, and higher frequency electromagnetic waves can be absorbed.

The thickness of each barrier layer 110, 110' is between 0.1 nm and 500 nm, and the thickness of each carrier confinement layer 111 is between 0.1 nm and 500 nm. As shown in FIG. 1, the thickness T1 of the barrier layer 110 and the thickness T1 of the carrier confinement layer 111 are not necessarily the same. In this embodiment, the thickness T1 of the barrier layer 110 is greater than the thickness T2 of the carrier confinement layer 111.

In an embodiment, at least two carrier confinement layers 111 will have different thicknesses or different energy gap widths. In another embodiment, the two carrier confinement layers 111 with different energy gap widths may be adjacent to each other. As long as the energy band structure of the electromagnetic wave shield 1 can have a quantum well, the present invention does not limit the implementation of the quantum well structure 11.

Accordingly, in the embodiment of the present invention, by adjusting the material and thickness of each barrier layer 110, or adjusting the material and thickness of each carrier confinement layer 111, the quantum well structure 11 can be used to at least absorb the frequency range from 1GHz to At least one electromagnetic wave between 300 GHz.

The plurality of barrier layers 110 and the plurality of carrier confinement layers 111 of the quantum well structure 11 can be manufactured by physical vapor deposition or chemical vapor deposition. In one embodiment, the quantum well structure 11 is prepared by sputtering, which can reduce the manufacturing cost.

[Second Embodiment]

Please refer to FIG. 3, which is a schematic diagram of an electromagnetic wave shield according to a second embodiment of the present invention. In this embodiment, the two barrier layers 110 are both composite material layers, and each barrier layer 110 includes a substrate M1 and a plurality of quantum dots QD embedded in the substrate M1. In this way, both barrier layers 110 can be used as a wave absorbing material, which can further enhance the effect of electromagnetic wave absorption.

[Third Embodiment]

Please refer to FIG. 4, which is a schematic diagram of an electromagnetic wave shield according to a third embodiment of the present invention. Elements in this embodiment that are the same as or similar to the previous embodiment have the same reference numbers, and the same parts are not described again.

In the electromagnetic wave shield 1'of this embodiment, the two barrier layers 110, 110" are both composite material layers, and the two composite material layers respectively have base materials M1, M2 of different materials or quantum dots QD1 of different materials. QD2.

In detail, in the quantum well structure 11 of this embodiment, the substrate M1 of one barrier layer 110 is different from the substrate M2 of the other barrier layer 110". In addition, the quantum dots QD1 embedded in the substrate M1 The material of QD2 is different from that of the quantum dot QD2 embedded in the substrate M2.

By choosing different substrates M1 and M2, or using different quantum dots QD1 and QD2, the two barrier layers 110, 110" can have different energy gap widths, respectively, and can absorb electromagnetic waves in different wavelength bands In one embodiment, the energy gap width of the substrate M1 is greater than the energy gap width of the substrate M2.

In addition, in this embodiment, the electromagnetic wave shield 1'further includes an electron transmission structure 12. The electron transport structure 12 is disposed on one side of the quantum well structure 11, and at least a part of the electron transport structure 12 has conductivity. The electron transmission structure 12 can assist the quantum well structure 11 to absorb more electromagnetic waves EM.

Specifically, the electron transmission structure 12 includes at least one single conductive layer or at least one composite conductive layer. In other words, the electron transmission structure 12 may be a single-layer structure or a multi-layer structure. The invention is not limited.

Please refer to FIG. 4 first, the electron transmission structure 12 is a single conductive layer, and the single conductive layer directly contacts the quantum well structure 11. In an embodiment, the material of the single conductive layer may be a material with better electrical conductivity and thermal conductivity, such as metal or alloy. The metal is, for example, but not limited to, copper, nickel, molybdenum, gold, silver, aluminum, zinc, indium, and the like. Alloys such as, but not limited to, silicon germanium alloys, nickel aluminum alloys, copper zinc alloys, copper nickel alloys, and the like.

According to this, the energy gap width between the conductive band and the valence band of the electron transport structure 12 is very small. Regardless of whether the work function of the electron transmission structure 12 is higher than the work function of the barrier layer 110, when the electromagnetic wave EM enters from the electron transmission structure 12 (first side S1), electrons will gradually accumulate in the electron transmission structure 12 , And easily cross the energy barrier between the electron transport structure 12 and the barrier layer 110 to enter the quantum well. According to this, the electron transmission structure 12 cooperates with the quantum well structure 11 to make the electromagnetic wave EM more easily enter the quantum well and be absorbed.

In an embodiment, the material of the electron transmission structure 12 can be further selected from materials that can absorb low-frequency electromagnetic waves, such as copper, nickel, molybdenum, or alloys thereof. Accordingly, in addition to having good electrical conductivity, the electron transmission structure 12 also has better shielding characteristics against low-frequency electromagnetic waves. The aforementioned low-frequency electromagnetic waves refer to electromagnetic waves in the frequency range from 100 kHz to 1 GHz.

It should be noted that the better the electrical conductivity of the electron transmission structure 12, the better the shielding against low-frequency electromagnetic waves. In addition, the total thickness of the electron transmission structure 12 also affects the shielding of low-frequency electromagnetic waves. If the total thickness of the electron transmission structure 12 is too thin, the conductivity may be too low to shield low-frequency electromagnetic waves. On the other hand, if the total thickness of the electron transport structure 12 is too thick, the stress of the electron transport structure 12 and the quantum well structure 11 may be excessive. Accordingly, in an embodiment, the total thickness of the electron transport structure 12 ranges from 50 nm to 5000 nm.

That is to say, the electromagnetic wave shield 1 of the embodiment of the present invention has a quantum well structure 11 and an electron transmission structure 12, which can not only absorb high-frequency electromagnetic waves (frequency range from 1 GHz to 300 GHz), It can also absorb low-frequency electromagnetic waves (frequency range from 100MHz to 1GHz). Therefore, when the electromagnetic wave shield 1 is applied to a transmission line assembly or an electronic packaging structure, electromagnetic interference and signal mutual interference can be more effectively shielded.

In addition, the material of the electron transmission structure 12 is also selected to have better electrical conductivity and thermal conductivity. In this way, when the electromagnetic wave shield 1 is applied to a transmission line assembly or an electronic packaging structure, the electronic transmission structure 12 of the electromagnetic wave shield 1 can dissipate heat to a wire or a chip.

The electron transmission structure 12 of the embodiment of the present invention may also be a multilayer structure. Please refer to FIG. 5 for a schematic diagram of an electronic transmission structure according to another embodiment of the invention. In the embodiment shown in FIG. 5, the electron transmission structure 12 includes a first layer 120 and a second layer 121.

The first layer 120 is the outermost layer of the electron transport structure 12, and the second layer 121 is located between the quantum well structure 11 and the first layer 120. In detail, the outside of the first layer 120 is the first side S1 of the electromagnetic wave shield 1, and the second layer 121 is located between the barrier layer 110 of the quantum well structure 11 and the first layer 120.

The materials of the first layer 120 and the second layer 121 are not necessarily the same. In other words, the first layer 120 and the second layer 121 may also be conductive layers composed of two different conductive materials, respectively. For example, the first layer 120 may be a copper layer, and the second layer 121 may be a nickel layer, but the invention is not limited to this example. In addition, the thicknesses of the first layer 120 and the second layer 121 are not necessarily the same.

Please refer to FIG. 6, which is a schematic diagram of an electronic transmission structure according to another embodiment of the present invention. The difference between this embodiment and the previous embodiment is that in this embodiment, the first layer 120 is a single conductive layer, and the second layer 121' is a composite conductive layer. The second layer 121' includes a conductive portion 121a and an insulating portion 121b. That is to say, the second layer 121' does not necessarily need to be composed entirely of conductive material, and may also include a part of insulating material.

In addition, the conductive portions 121a and the insulating portions 121b are alternately distributed in a horizontal direction. It should be noted that the top view shape of the conductive portion 121a may be a continuous pattern or include multiple Separate parts. Therefore, although in the schematic cross-sectional view of the electron transmission structure 12 shown in FIG. 4, the conductive portion 121a has a plurality of parts separated from each other, the invention is not limited thereto.

In another embodiment, the first layer 120 may also be a composite conductive layer, and the second layer 121 may also be a single conductive layer. In yet another embodiment, the first layer 120 and the second layer 121 may also be composite conductive layers, and the conductive portion of the first layer 120 and the conductive portion of the second layer 121 may be staggered from each other. In other embodiments, the electron transport structure 12 is a composite conductive layer.

It should be noted that the electron transmission structure 12 in FIG. 1 can be replaced with any one of the electron transmission structures 12 in FIGS. 5 to 6. Based on the above, as long as the electron transmission structure 12 has a single conductive layer connected to the quantum well structure 11 or a conductive portion (eg, conductive portion 121a), when the electromagnetic wave shield 1 is applied to a transmission line assembly or an electronic packaging structure, the electron transmission structure Both 12 can assist the quantum well structure 11 to absorb electromagnetic waves EM. However, in the electron transmission structure 12, the higher the volume ratio of the portion having conductivity, the better the shielding effect of the electromagnetic wave shield 1 for low-frequency electromagnetic waves.

Please refer to FIG. 7, which is a schematic diagram of an electromagnetic wave shield according to a fourth embodiment of the present invention. The electromagnetic wave shield 1'of this embodiment further includes: another electron transmission structure 12'. The two electron transport structures 12, 12' are located on opposite sides of the quantum well structure 11, respectively. Accordingly, the outermost side of one of the electron transmission structures 12 is the first side S1 of the electromagnetic wave shield 1', and the outermost side of the other electron transmission structure 12' is the second side S2 of the electromagnetic wave shield 1'.

In addition, in the present embodiment, the quantum well structure 11 is a multiple quantum well structure, that is, it includes a plurality of barrier layers 110, 110' stacked alternately and a plurality of carrier confinement layers 111 (FIG. 7 shows two layers as an example ). It is worth noting that in the multiple quantum well structure, the two outermost layers are barrier layers 110, 110'. That is to say, in this embodiment, the two electron transport structures 12, 12' are two barrier layers 110, 110' connected to the quantum well structure 11, respectively.

Among the multiple barrier layers 110, 110', not every layer is a composite material layer. In other words, only part of the barrier layer 110 may be a composite material layer, and the other part of the barrier layer 110' It is a single material layer. In this embodiment, the barrier layer 110 connected to one of the electron transport structures 12 is a composite material layer, and the barrier layer 110' connected to the other electron transport structure 12' is a single material layer.

In addition, at least a portion of the other electron transport structure 12' will be electrically conductive. Specifically, another electron transport structure 12' will also include at least a single conductive layer or at least a composite conductive layer. The electron transport structure 12' may be a single-layer structure or a multi-layer structure. In other words, the structure of the electron transmission structure 12' may be the same as any one of the electron transmission structures 12 in FIGS. 4 to 6, and the implementation of the electron transmission structure 12' will not be described in detail below.

The structures of the two electron transmission structures 12, 12' need not be identical. For example, one of the electron transport structures 12 is a multilayer structure, and the structure of the other electron transport structure 12' may be a single-layer structure, but the invention is not limited to this example.

When the electromagnetic wave shield 1'of this embodiment is applied to a transmission line assembly, one of the electron transmission structures 12 can cooperate with the quantum well structure 11 to absorb the signal generated by the transmission line assembly. The other electron transmission structure 12' can cooperate with the quantum well structure 11 to further absorb electromagnetic waves outside the transmission line assembly, so as to prevent external electromagnetic waves from entering the transmission line assembly and affecting the signal transmission quality. In addition, since a part of the electron transmission structure 12' can have both electrical conductivity and thermal conductivity, it can also provide heat dissipation to the transmission line assembly. The following further describes different embodiments in which the electromagnetic wave shields 1, 1'are applied to transmission line assemblies.

Please refer to FIG. 8, which is a schematic cross-sectional view of the transmission line assembly according to the first embodiment of the present invention. The transmission line assembly P1 of this embodiment includes a wire group 2 and an electromagnetic wave shield 1 (1').

Specifically, the transmission line assembly P1 may be a flexible flat cable, a flexible circuit board, a flexible flat cable, or a coaxial cable. In this embodiment, the wire group 2 includes at least one wire 21 for transmitting signals (a plurality of examples are shown in FIG. 9) and an insulating layer 22 covering the wire.

The material of the insulating layer 22 is, for example, polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), polyether sock (PES) Polyary acid Ester (polyarylate) or other suitable materials, but the invention is not limited thereto.

The detailed structure of the electromagnetic wave shield 1 (1') can refer to FIGS. 1 to 7 and will not be repeated here. The electromagnetic wave shield 1 (1') is provided on the wire group 2. Specifically, the electromagnetic wave shield 1 (1') surrounds the wire group 2, that is, covers the outer surface of the insulating layer 22 to shield electromagnetic wave interference. In the embodiment of Fig. 8, the electromagnetic wave shield 1 (1') completely covers the entire wire group 2. However, in other embodiments, the electromagnetic wave shield 1 (1') may cover only part of the surface of the wire group 2.

It is worth noting that, in this embodiment, the electromagnetic wave shield 1 (1') is disposed toward the wire group 2 with the first side S1. That is, when the electromagnetic wave shield 1 (1') is disposed on the wire group 2, the barrier layer 110 or the electron transmission structure 12 having quantum dots QD will be connected to the wire group 2. According to this, most of the high-frequency electromagnetic waves radiated when the wire 21 transmits high-frequency signals can be absorbed by the quantum well structure 11 to avoid mutual signal interference.

In one embodiment, at least a portion of the electron transport structure 12 (12') is composed of materials having electrical and thermal conductivity (e.g., metal or alloy). Compared with other embodiments, the quantum well structure 11 cooperates with the electron transmission structure 12 (12'), in addition to more effectively shielding low-frequency electromagnetic waves and high-frequency electromagnetic waves, it can also dissipate heat to the wire group 2.

Please refer to FIG. 9, which is a schematic partial cross-sectional view of a transmission line assembly according to a second embodiment of the present invention. The transmission line assembly P2 of this embodiment is a flexible flat cable, and includes at least a wire set 2 and an electromagnetic wave shield 1 (1'). The wire group 2 of this embodiment includes a plurality of wires 21 separated from each other and at least one insulating layer 22. In this embodiment, two insulating layers 22 are provided on opposite sides of the wire 21 through an insulating adhesive layer (not shown).

The detailed structure of the electromagnetic wave shield 1 (1') can refer to FIGS. 1 to 7 and will not be repeated here. The electromagnetic wave shield 1 (1') is provided on the wire group 2 to prevent electromagnetic wave interference. Further, the electromagnetic wave shield 1 (1') can be disposed on one of the insulating layers 22 through a conductive adhesive layer (not shown), and the first side S1 (the barrier layer 110 or the electron transmission structure 12) It is provided toward the insulating layer 22.

Please refer to FIG. 11, which is a schematic cross-sectional view of a transmission line assembly according to another embodiment of the invention. As shown in FIG. 11, the transmission line assembly P3 is a coaxial cable, and includes at least one wire 21, an insulating layer 22, an electromagnetic wave shield 1 (1 ′), and a cladding layer 3.

The wire 21 is coated in the insulating layer 22 for transmitting signals. The electromagnetic wave shield 1 (1') covers the outer surface of the insulating layer 22, and the electromagnetic wave shield 1 (1') is located between the cladding layer 3 and the insulating layer 22 for shielding electromagnetic interference. The material of the cladding layer 3 is an insulating material, and is the outermost layer of the transmission line assembly P3, which serves as a protective layer.

The first side S1 of the electromagnetic wave shield 1 will face the wire 21, and the second side S2 will face the insulating layer 22 toward the cladding layer 3. If the electromagnetic wave shield 1 does not have the electron transmission structure 12, the barrier layer 110 with quantum dots QD will be located between the insulating layer 22 and the carrier confinement layer 111.

If the electromagnetic wave shield 1'has only one electron transmission structure 12, the electron transmission structure 12 will be located between the insulating layer 22 and the quantum well structure 11, and the outer surface of the quantum well structure 11 will face the cladding layer 3. In another embodiment, the electromagnetic wave shield 1'has two electron transmission structures 12, 12', one of which is located between the quantum well structure 11 and the insulating layer 22. Another electron transmission structure 12' is located between the quantum well structure 11 and the cladding layer 3, and can be used to shield external low-frequency electromagnetic waves and assist heat dissipation.

[Beneficial effect of embodiment]

One of the beneficial effects of the present invention is that, in the electromagnetic wave shield 1 (1') provided by the present invention and the transmission line components P1 to P3 using the same, the "electromagnetic wave shield 1 (1') includes a quantum well structure 11" And the technical solution of "at least one of the two barrier layers 110, 110' is a composite material layer, and the composite material layer includes a base material M1 and a plurality of quantum dots QD buried in the base material M1", The electromagnetic wave shield 1 (1') is applied to absorb high frequency and low frequency electromagnetic wave noise to suppress electromagnetic interference.

Further, in the electromagnetic wave shield 1 (1') of the embodiment of the present invention, the barrier layers 110, 110" having quantum dots QD themselves can be used as a wave absorbing material, which can enhance the effect of electromagnetic wave absorption. In addition, it has quantum QD-point barrier layer 110, 110 'may have a larger energy gap width Eg _1. Accordingly, the barrier layers 110, 110" can further assist the quantum well structure 11 to absorb electromagnetic waves of higher frequency bands.

In addition, in the electromagnetic wave shield 1'of the embodiment of the present invention, the electron transmission structure 12 (12') can assist the quantum well structure 11 to more easily absorb electromagnetic waves to suppress crosstalk between signals. In addition, the electron transmission structure 12 (12') itself can also absorb low-frequency electromagnetic waves in the frequency range from 100 kHz to 1 GHz.

Accordingly, the electromagnetic wave shield 1 (1') of the embodiment of the present invention can absorb not only high-frequency electromagnetic waves (frequency range from 1 GHz to 300 GHz) but also low-frequency electromagnetic waves (frequency range from 100 MHz to 1 GHz). Therefore, when the electromagnetic wave shield 1 is applied to the transmission line assemblies P1 to P3 or the electronic packaging structure, it can shield electromagnetic interference and suppress signal mutual interference more effectively. Accordingly, when the electromagnetic wave shield 1 (1') of the embodiment of the present invention is actually applied to the transmission line components P1~P3, it can reduce signal loss, effectively absorb reflected waves and avoid crosstalk.

In addition, the material of the electron transport structure 12 (12') may be selected to have better electrical and thermal conductivity. As such, when the electromagnetic wave shield 1 is applied to the transmission line components P1 to P3 or the electronic packaging structure, the electron transmission structure 12 (12') of the electromagnetic wave shield 1 can improve heat dissipation efficiency.

In the prior art, a ferrite coating or a graphene coating is used as an electromagnetic wave shielding layer, and its total thickness is about 100 to 300 μm. In comparison, the total thickness of the electromagnetic wave shield 1 (1') of the embodiment of the present invention is 1 µm or thinner. That is to say, the total thickness of the electromagnetic wave shield 1 of the embodiment of the present invention is thinner and lighter, that is, it is only 1/100 times to 1/300 times the total thickness of the existing electromagnetic wave shielding layer, but it can be applied to the shielding frequency range Wider electromagnetic waves.

In addition, the existing electromagnetic wave shielding layer is usually prepared by a chemical coating process, and in the chemical coating process, the waste liquid after the chemical reaction may cause environmental pollution. In comparison, the manufacturing method (eg, sputtering) of the electromagnetic wave shield 1 of the embodiment of the present invention can reduce environmental pollution.

The contents disclosed above are only preferred and feasible embodiments of the present invention, The scope of patent application of the present invention is limited, so all equivalent technical changes made by using the description and drawings of the present invention are included in the patent application scope of the present invention.

1: electromagnetic wave shield

S1: First side

S2: Second side

11: Quantum well structure

110, 110’: barrier layer

T1: Barrier layer thickness

T2: Carrier limited layer thickness

111: Carrier localization layer

M1: substrate

QD: Quantum dots

Claims (16)

An electromagnetic wave shield includes a quantum well structure, the quantum well structure includes two barrier layers and at least one carrier confinement layer between the two barrier layers, wherein two barrier layers At least one of the layers is a composite material layer, and the composite material layer includes a substrate and a plurality of quantum dots embedded in the substrate. The electromagnetic wave shield according to item 1 of the patent application range, wherein the energy gap width of the base material is smaller than the energy gap width of the material of the quantum dots. The electromagnetic wave shield as described in item 1 of the patent application range, wherein the substrate is a non-stoichiometric compound and has a plurality of anion vacancies. The electromagnetic wave shield as described in item 1 of the patent application range, wherein the material of the quantum dots is in the group consisting of oxide, carbide, nitride, oxynitride, p-type semiconductor, and any combination thereof one of them. The electromagnetic wave shield according to item 1 of the patent application range, wherein the material of the carrier confinement layer is a semiconductor, a metal, an alloy, or any combination thereof. The electromagnetic wave shield according to item 1 of the patent application scope further includes: an electron transmission structure, which is disposed on one side of the quantum well structure, and at least a part of the electron transmission structure has conductivity. The electromagnetic wave shield according to item 6 of the patent application scope, wherein the electron transmission structure includes a first layer and a second layer between the first layer and the quantum well structure, the first At least one of the one layer or the second layer is a composite conductive layer. The composite conductive layer includes a conductive portion and an insulating portion. The conductive portion and the insulating portion are staggered in a horizontal direction. The electromagnetic wave shield according to item 1 of the patent application range, wherein the thickness of the barrier layer is greater than the thickness of the carrier confinement layer. The electromagnetic wave shield according to item 1 of the patent application scope, wherein the quantum The well structure is a multiple quantum well structure. The quantum well structure includes a plurality of barrier layers and a plurality of carrier confinement layers that are alternately stacked, and one of the barrier layers on the outermost side is a composite material layer . The electromagnetic wave shield according to item 1 of the scope of the patent application, wherein both of the barrier layers are the composite material layers, and the two composite material layers each have a substrate of different materials. The electromagnetic wave shield according to item 1 of the patent application scope, wherein both of the barrier layers are the composite material layers, and the two composite material layers have quantum dots of different materials, respectively. A transmission line assembly, comprising: a wire group including at least one wire and an insulating layer covering the wire; and an electromagnetic wave shielding member disposed on the wire group, and the electromagnetic wave shielding member includes a Quantum well structure, wherein the quantum well structure includes two barrier layers and at least one carrier confinement layer between the two barrier layers, wherein at least one of the two barrier layers The latter is a composite material layer, and the composite material layer includes a substrate and a plurality of quantum dots embedded in the substrate. The transmission line component as described in item 12 of the patent application range, wherein the substrate is a non-stoichiometric compound and has multiple anion vacancies, and the material of the quantum dot is an insulating material. The transmission line assembly according to item 12 of the patent application range, wherein the energy gap width of the base material is smaller than the energy gap width of the material of the quantum dots. The transmission line component as described in item 12 of the patent application range, wherein the material of the quantum dot is one of the group consisting of oxide, carbide, nitride, oxynitride, p-type semiconductor, and any combination thereof One kind. The transmission line assembly according to item 12 of the patent application scope further includes: an electron transmission structure located between the quantum well structure and the wire group, Wherein, at least a part of the electron transport structure has conductivity.

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