COMPOSITE PANE COMPRISING A SUN SHADING COATING

Abstract

A composite pane includes an outer pane having an exterior-side surface and an interior-side surface, an inner pane having an exterior-side surface and an interior-side surface, and a thermoplastic intermediate layer, which joins the interior-side surface of the outer pane to the exterior-side surface of the inner pane. The composite pane has a sun shading coating between the outer and inner panes. The sun shading coating includes, starting from the inner pane toward the outer pane, a layer sequence first dielectric module, first silver layer Ag1, second dielectric module, second silver layer Ag2, third dielectric module, third silver layer Ag3, fourth dielectric module, wherein the silver layers have, relative to one another, a geometrical layer thickness of Ag2>Ag1>Ag3, and the silver layers of the sun shading coating have a relative geometrical layer thickness of 1.0<Ag1/Ag3 and 1.2<Ag2/Ag3<2.

Claims

1. A composite pane, comprising an outer pane having an exterior-side surface and an interior-side surface, an inner pane having an exterior-side surface and an interior-side surface, and a thermoplastic intermediate layer, which joins the interior-side surface of the outer pane to the exterior-side surface of the inner pane, wherein the composite pane has at least one sun shading coating between the outer pane and the inner pane, wherein the sun shading coating comprises, starting from the inner pane toward the outer pane, a layer sequence first dielectric module, first silver layer, second dielectric module, second silver layer, third dielectric module, third silver layer, fourth dielectric module, wherein the first, second and third silver layers have, relative to one another, a geometrical layer thickness of Ag2>Ag1>Ag3, where Ag1 is the geometrical layer thickness of the first silver layer, Ag2 is the geometrical layer thickness of the second silver layer, and Ag3 is the geometrical layer thickness of the third silver layer, and the first, second and third silver layers of the sun shading coating have a relative geometrical layer thickness of 1.0<Ag1/Ag3 and 1.2<Ag2/Ag3<2.

2. The composite pane according to claim 1, wherein the first, second, third and fourth dielectric modules have a relative optical layer thickness of M2/M11.9, M2/M30.8, and M2/M42, where M1 is the optical layer thickness of the first dielectric module, M2 is the optical layer thickness of the second dielectric module, M3 is the optical layer thickness of the third dielectric module and M4 is the optical layer thickness of the fourth dielectric module.

3. The composite pane according to claim 1, wherein the first dielectric module, the second dielectric module, the third dielectric module, and/or the fourth dielectric module have at least one dielectric layer based on silicon nitride.

4. The composite pane according to claim 1, wherein the first dielectric module, the second dielectric module, the third dielectric module, and/or the fourth dielectric module include at least one first dielectric layer based on silicon nitride and at least one second dielectric layer based on zinc oxide.

5. The composite pane according to claim 1, wherein the first dielectric module, the second dielectric module, the third dielectric module, and/or the fourth dielectric module include at least one first dielectric layer based on silicon nitride, at least one second dielectric layer based on zinc oxide, and at least one third dielectric layer based on a mixed tin-zinc oxide.

6. The composite pane according to claim 1, wherein the sun shading coating includes, above and/or below the first, second and third silver layers, in each case at least one metallic blocking layer, which has a geometrical thickness of less than 1 nm.

7. The composite pane according to claim 1, wherein the first silver layer, the second silver layer, and the third silver layer have, in each case, a geometrical thickness of 5 nm to 25 nm.

8. The composite pane according to claim 7, wherein the first silver layer has a geometrical thickness of 7 nm to 14 nm, the second silver layer has a geometrical thickness of 7 nm to 16 nm, and the third silver layer has a geometrical thickness of 6 nm to 13 nm.

9. The composite pane according to claim 1, wherein the first dielectric module, the second dielectric module, the third dielectric module, and the fourth dielectric module have, in each case, a geometrical thickness of 10 nm to 100 nm.

10. The composite pane according to claim 1, wherein the sun shading coating is applied on the exterior-side surface of the inner pane.

11. The composite pane according to claim 1, wherein the sun shading coating has at least two bus bars via which the sun shading coating is connectable to an electrical voltage source.

12. The composite pane according to claim 1, wherein heating wires are present between the exterior-side surface of the inner pane and the interior-side surface of the outer pane.

13. The composite pane according to claim 1, wherein the sun shading coating contains exactly three silver layers.

14. A method for producing a composite pane according to claim 1 comprising: a) applying a sun shading coating to the interior-side surface of the outer pane, or to the exterior-side surface of the inner pane, or introducing the sun shading coating into a thermoplastic intermediate layer, b) producing a layer stack comprising at least, in this order, the outer pane, the thermoplastic intermediate layer, and the inner pane, and c) joining the layer stack comprising at least the outer pane, the thermoplastic intermediate layer, and the inner pane to form the composite pane.

15. A method comprising providing a composite pane according to claim 1 in a motor vehicle-preferably as a windshield, rear window, side window, and/or roof panel.

16. The composite pane according to claim 9, wherein the first dielectric module, the second dielectric module, the third dielectric module, and the fourth dielectric module have, in each case, a geometrical thickness of 20 nm to 90 nm.

17. The composite pane according to claim 16, wherein the first dielectric module, the second dielectric module, the third dielectric module, and the fourth dielectric module have, in each case, a geometrical thickness of 70 nm to 85 nm.

18. The method according to claim 15, wherein the composite pane is a windshield of a motor vehicle.

Description

[0097] The drawings are simplified schematic representations and are not to scale. The drawings in no way restrict the invention.

[0098] They depict:

[0099] FIG. 1 a cross-section through a first embodiment of the composite pane according to the invention having a sun shading coating,

[0100] FIG. 2 a cross-section through another embodiment of the composite pane according to the invention having a sun shading coating,

[0101] FIG. 3 a cross-section through another embodiment of the composite pane according to the invention having a sun shading coating,

[0102] FIG. 4 a schematic representation of the structure of a sun shading coating according to the invention applied on the inner pane of the composite pane, and

[0103] FIG. 5 a flow chart of an embodiment of the method according to the invention.

[0104] FIG. 1 depicts a cross-section through an embodiment of the composite pane 100 according to the invention having a sun shading coating 4. The composite pane 100 comprises an outer pane 1 and an inner pane 2 joined to one another via a thermoplastic intermediate layer 3. The composite pane 100 can, for example, be provided as a windshield of a passenger car, with the outer pane 1 facing the external surroundings and the inner pane 2 facing the vehicle interior. The outer pane 1 has an outer surface (I) and an inner surface (II). The inner pane 2 has an outer surface (III) and an inner surface (IV). The outer surfaces (I) and (III) face the external surroundings; the inner surfaces (II) and (IV) face the vehicle interior. The inner surface (II) of the outer pane 1 and the outer surface (III) of the inner pane 2 face one another. In this embodiment, a sun shading coating 4 according to the invention is arranged on the inner surface (II) of the outer pane 1. The sun shading coating 4 extends over the entire inner surface (II), preferably minus a circumferential frame-shaped coating-free region, for example, with a width of 8 mm. The coating-free region can then be hermetically sealed by bonding to the thermoplastic intermediate layer 3. The sun shading coating 4 is thus advantageously protected against damage and corrosion. According to the invention, the sun shading coating 4 comprises at least three functional silver layers, each of which has a geometrical layer thickness between 5 nm and 20 nm, with each functional silver layer being arranged between dielectric modules, for example, layers of silicon nitride. The silver layers (Ag1, Ag2, Ag3) of the sun shading coating according to the invention have a layer thickness relative to one another of 1.0<Ag1/Ag3 and 1.2<Ag2/Ag3<2, where Ag2>Ag1>Ag3. The dielectric modules (M1, M2, M3, M4) have an optical layer thickness relative to one another of M2/M11.9, M2/M30.8, and M2/M42. The structure of the sun shading coating 4 according to the invention is described in more detail below with FIG. 4 and the examples and comparative examples explained there. The sun shading coating 4 results in reduced heating of the vehicle interior and of the inner pane 2 due to the reflection of infrared radiation. Energy reflection RE>30%, total solar transmittance TTS<45%, and light transmittance TL>72.5% can be achieved. Also, with the sun shading coating 4 according to the invention, good optical and aesthetic properties of the composite pane 100 are achieved in addition to improved thermal comfort, at the same time. The sheet resistance of the sun shading coating 4 is between 1.0 /sq and 1.5 /sq, as a result of which the coating has good compatibility with 14V/42V DC/DC converters.

[0105] FIG. 2 depicts a cross-section through another embodiment of the composite pane 100 according to the invention having a sun shading coating 4. In contrast to FIG. 1, the sun shading coating 4 is arranged not on the inner surface (II) of the outer pane 1, but on a carrier film 5 in the intermediate layer 3. The carrier film 5 preferably contains or is made of polyethylene terephthalate (PET) and has, for example, a thickness of 50 m. The sun shading layer 4 according to the invention comprises a layer structure, which is explained in greater detail with regard to FIG. 4. The carrier film 5 with the sun shading coating 4 is arranged between a first thermoplastic film 3a and a second thermoplastic film 3b. In the resulting composite pane, the thermoplastic films 3a and 3b and the carrier film 5 form the thermoplastic intermediate layer 3. The thermoplastic films 3a and 3b preferably contain or are made of PVB and have, for example, a layer thickness of 0.38 mm. The carrier film 5 is somewhat smaller than the outer pane 1, the inner pane 2, and the thermoplastic films 3a and 3b. The carrier film 6 is arranged in the composite such that the carrier film 5 does not extend all the way to the lateral edges of the composite glass. As a result, the carrier film 5 is surrounded in the edge region of the composite pane for example, circumferentially by the thermoplastic films 3a and 3b, with a width of approx. 8 mm. The sun shading coating 4 on the carrier film 5 is thus advantageously protected against damage and, in particular, corrosion.

[0106] FIG. 3 depicts a cross-section through another embodiment of the composite pane 100 according to the invention having a sun shading coating 4. In contrast to FIG. 1, the sun shading coating 4 is arranged not on the inner surface (II) of the outer pane 1, but on the outer surface (III) of the inner pane 2, with a circumferential edge region of the outer surface (III) not provided with the sun shading coating 4. In this embodiment as well, the sun shading coating 4 is advantageously protected against damage and corrosion. For the rest, this embodiment corresponds to the design depicted in FIG. 1.

[0107] FIG. 4 depicts a schematic structure of a sun shading coating 4 according to the invention. In the embodiment depicted, the sun shading coating 4 is applied on the inner side III of the inner pane 2 as a substrate. The sun shading coating 4 depicted contains three transparente functional silver layers Ag1, Ag2, and Ag3, which are in particular the infrared-radiation-reflecting layers. The functional silver layers have a certain thickness relative to one another; specifically, provision is made for the following to be true for the relative geometrical layer thicknesses Ag2>Ag1>Ag3, 1.0<Ag1/Ag3 and 1.2<Ag2/Ag3<2. In other words, the layer thickness of the third silver layer Ag3, which is arranged closest to the outer pane 1 is thinner than the layer thickness of the first silver layer Ag1, closest to the inner pane 2, while the second silver layer Ag2, which is positioned between the first silver layer Ag1 and the third silver layer Ag3 in the layer sequence, is the silver layer with the greatest layer thickness. The silver layers can be deposited, for example, by cathodic sputtering in an argon atmosphere.

[0108] Dielectric modules M1, M2, M3, and M4 including dielectric layers are in each case arranged above, below, and between the silver layers Ag1, Ag2, and Ag3. These dielectric modules (M1, M2, M3, M4) preferably have, relative to one another, an optical layer thickness M2/M11.9, M2/M30.8, and M2/M42. The dielectric module M1 is thus arranged below the first silver layer Ag1 directly on the inner side III of the inner pane 2; the second dielectric module M2 is arranged above the first silver layer Ag1. The first dielectric module M1 can, for example, be structured, starting from the inner pane 2, as a layer sequence of silicon nitride, ZnSnOx, and ZnO layers. The silicon nitride layer can be deposited from silicon nitride in a nitrogen-containing atmosphere; the zinc oxide layer, from zinc oxide in an oxygen-containing atmosphere.

[0109] The sun shading coating 4 contains at least one blocking layer; particularly preferably each functional silver layer Ag1, Ag2, Ag3 is situated, as depicted, in direct contact with at least one blocking layer B1, B2, and B3. According to the invention, the blocking layers preferably contain or are made of at least nickel, chromium, or alloys thereof and/or titanium chromium. The blocking layers B (B1, B2, B3) are preferably arranged between at least one functional silver layer and at least one dielectric layer. The blocking layers B protect the functional layer during heating, in particular during production of the composite pane according to the invention.

[0110] The invention is explained with reference to the following Examples according to the invention and Comparative Examples not according to the invention.

EXAMPLES

[0111] All optical, aesthetic, and energy properties of the composite panes according to the Examples and the Comparative Examples were measured in the laminated state. In the Examples and the Comparative Examples, the sun shading coating 4 was applied to the outer side III of a clear inner pane 2 (Example Planiclear) in accordance with FIG. 4 and laminated with a thermoplastic intermediate layer 3 and an outer pane 1 in accordance with the structure of FIG. 3. A non-tinted PVB film was used in the intermediate layer.

[0112] The Examples and Comparative Examples have the same basic structure described, but differ in the sun shading coatings used.

[0113] Examples 1 through 5 according to the invention and Comparative Examples 1 through 3 not according to the invention were produced as a composite pane (windshield for a vehicle) with the sun shading coatings indicated.

[0114] For each Example and Comparative Example, the stack structure of the sun shading coating (layers and layer thicknesses) and the optical properties of the coating in the finished composite pane are indicated.

[0115] The layer sequences and layer thicknesses of the sun shading coatings in accordance with Examples 1 to 5 according to the invention as well as the Comparative Examples 1 to 3, shown in comparison thereto, are presented in Table 1. The relativen layer thicknesses of the silver layers and of the dielectric modules, as well as the values of the optical, electrical, and energy properties for the Examples 1 to 5 according to the invention and for the Comparative Examples 1 to 3 not according to the invention are reported in Table 2. All layer thicknesses of the silver layers and of the layers of the modules are indicated as geometrical layer thicknesses. The relative layer thicknesses of the silver layers, indicated as thickness ratios Ag2/Ag1, Ag2/Ag3, and Ag1/Ag3 refer to the geometrical layer thicknesses. For the relative layer thicknesses of the dielectric modules, indicated as thickness ratios M2/M1, M2/M3, and M2/M4, the optical thicknesses were used.

Abbreviations

[0116] RE energy reflection [%] [0117] TL visible light transmittance [%] [0118] TTS total transmitted thermal radiation [%] [0119] TE total transmitted energy [%] [0120] RL 8 visible reflection at a viewing angle of 8 [%] [0121] RL 60 visible reflection at a viewing angle of 60 [%] [0122] a*, b* color coordinates in the CIE color space (International Commission on Illumination), measured in each case in reflection at an angle of 60 and at an angle of 8 [0123] a*, b* difference in the color coordinates when measured in reflection at 60 and at 8 [0124] Color R* color impression of the external reflection color in each case in reflection at 60 and at 8 perceived by the viewer of the composite pane [0125] Rsq sheet resistance of the sun shading coating [/sq]

[0126] The values for light transmittance (TL) and reflection (RL) are based on illuminant A, which by definition is based on the relative radiation distribution of the Planckian radiator with 2856 Kelvin.

TABLE-US-00001 TABLE 1 Layer Structures of the Sun Shading Coating per Examples 1 to 5 and Comparative Examples 1 to 3 Layer Layer Thicknesses [nm] per Thicknesses [nm] Layer Example According to the per Comparative se- Layer Invention Example quence material #1 #2 #3 #4 #5 #1 #2 #3 Outer Glass pane 1 M1 SiZrN.sub.x 13.2 12.5 13.9 12.8 15.5 11.9 13.4 13.0 ZnSnO.sub.x 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 ZnO 11.0 12.0 11.0 12.0 11.0 11.0 11.0 12.0 Ag1 Ag 10.3 9.4 10.7 10.0 9.6 10.0 10.5 10.0 B1 NiCr 0.4 0.4 0.4 0.5 0.4 0.5 0.4 0.5 M2 ZnO 11.0 12.0 11.0 12.0 11.0 11.0 11.0 12.0 SiZrN.sub.x 11.1 11.0 11.1 10.7 13.9 11.3 11.1 10.8 Si.sub.3N.sub.4 18.8 19.3 18.8 18.5 19.4 18.9 18.8 18.6 SiZrN.sub.x 8.5 8.6 8.5 8.4 8.5 8.6 8.5 8.4 ZnSnO.sub.x 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 ZnO 11.0 12.0 11.0 12.0 11.0 11.0 11.0 12.0 Ag2 Ag 13.1 12.1 13.5 13.0 13.0 11.0 13.5 13.1 B2 NiCr 0.0 0.0 0.0 0.0 0.0 0.2 0.0 0.0 M3 ZnO 11.0 12.0 11.0 12.0 11.0 11.0 11.0 12.0 Sl.sub.3N.sub.4 39.9 39.1 40.4 39.4 41.4 40.2 40.3 39.2 SiZrN.sub.x 8.4 7.8 8.4 8.4 9.5 8.5 8.4 8.3 ZnSnO.sub.x 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 ZnO 11.0 12.0 11.0 12.0 11.0 11.0 11.0 12.0 Ag3 Ag 9.5 9.0 10.2 9.5 9.3 10.4 12.5 12.8 B3 NiCr 0.2 0.0 0.2 0.2 0.2 0.3 0.2 0.2 M4 Zno 11.0 12.0 11.0 12.0 11.0 11.0 11.0 12.0 SiZrN.sub.4 7.4 8.1 7.4 7.6 9.7 7.3 7.4 7.6 Si.sub.3N.sub.4 7.5 8.0 7.4 7.6 8.9 7.4 7.5 7.6

TABLE-US-00002 TABLE 2 Thickness ratios and Optical Properties in the Laminate per Examples 1 to 5 and Comparative Examples 1 to 3 Thickness Ratios and Optical Properties Thickness Ratios and Optical per Comparative Properties per Example Example #1 #2 #3 #4 #5 #1 #2 #3 Thickness Ratios Ag2/Ag1 1.28 1.29 1.26 1.30 1.35 1.10 1.29 1.31 Ag2/Ag3 1.38 1.34 1.33 1.37 1.40 1.06 1.08 1.03 Ag1/Ag3 1.08 1.04 1.06 1.05 1.03 0.96 0.84 0.78 M2/M1 2.08 2.14 2.04 2.08 2.19 2.19 2.07 2.07 M2/M3 0.90 0.92 0.89 0.90 0.90 0.90 0.89 0.90 M2/M4 2.65 2.52 2.65 2.56 2.68 2.68 2.65 2.57 Optical Properties TL 72.8 75.4 72.5 72.7 74.1 72.5 72.5 72.4 RL 8 10.0 9.0 10.1 10.0 10.1 9.2 9.5 9.3 a*R 8 1.0 1.0 1.0 1.0 1.0 1.2 2.6 1.9 b*R 8 9.0 9.0 9.0 9.0 9.0 7.0 11.1 10.7 a*R 60 0.0 0.4 0.0 0.5 0.9 2.3 1.2 0.8 b*R 60 5.0 4.7 4.6 5.0 5.0 2.4 5.4 4.9 Color blue blue blue blue blue violet blue blue R*8 Color blue blue blue blue blue blue- violet violet R*60 green a*R 1.0 0.6 1.0 0.5 3.5 3.5 3.8 2.7 (8 vs. 60) b*R 4.0 4.3 4.4 4.0 4.6 4.6 5.7 5.8 (8 vs. 60) RE 35.8 33.5 37.0 35.2 34.1 33.5 38.9 38.2 TE 36.1 39.3 35.2 36.6 38.1 37.7 34.0 34.5 TTS 41.8 44.9 40.8 42.3 43.8 43.5 39.5 40.1 Rsq 1.26 1.41 1.18 1.28 1.31 1.35 1.09 1.12

[0127] According to the invention, composite panes having a sun shading coating structured according to the invention are provided which were successfully improved in terms of energy and electrical properties, thermal and visual comfort, and at the same time in terms of aesthetic appearance and were further optimized compared to known composite panes having sun shading coatings. Total transmitted thermal radiation (TTS) of less than 45% was achieved such that the corresponding frequently requested customer specification can be met. In addition, light transmittance TL72.5% was achieved such that the composite pane can be used as a windshield; and also when combined with common wire heaters, the legal requirement TL70% is achieved. In addition, optimum aesthetic appearance without undesirable color tones in the reflection of the composite pane is achieved. In particular, undesirable red, yellow, violet, and green reflections or hazing of the composite pane can be avoided. A substantially constant, desirable color reflection of the composite pane can be achieved regardless of the viewing angle. Furthermore, the sun shading coatings according to the invention have sheet resistance between 1.0 /sq and 1.5 /sq and are thus well suited for heating with a supply voltage of 42 V.

[0128] To further illustrate the advantages of the thickness combination of the silver layers, exemplary optical and energy properties of silver coatings with the respective thickness ratios indicated are reported in Table 3. The thickness of the dielectric modules and the order of the layers in the layer stack are identical in each case.

TABLE-US-00003 TABLE 3 Overview of the optical properties TL, TTS, RL 60, and the external reflection color at 60 for the various possible thickness ratios of the silver layers Ag1, Ag2, and Ag3. Permutations Ag TL TTS RL 60 a*R 60 b*R 60 Ag1 > Ag2 > Ag3 73.1 43.4 17.9 8.0 1.5 Ag1 > Ag3 > Ag2 69.3 43.3 21.3 13.6 5.7 Ag2 > Ag1 > Ag3 74.6 42.9 17.1 1.0 3.5 Ag2 > Ag3 > Ag1 72.7 42.4 19.6 0.2 3.6 Ag3 > Ag1 > Ag2 67.6 42.7 23.9 11.8 11.8 Ag3 > Ag2 > Ag1 69.5 42.3 23.0 5.5 11.8 Ag1 = Ag2 = Ag3 (10.7 nm) 72.0 43.2 19.6 7.7 4.4

[0129] As can be seen in Table 3, good optical and energy properties as well as appealing coloration can be achieved only with the thickness ratios of the silver layers according to the invention, with the following stipulation for the thickness of the silver layers: Ag2>Ag1>Ag3. Layers with the following properties are considered acceptable: TL72.5%, TTS45%, RL 6017.5%. In addition, the color coordinates should be the smallest possible and particularly preferably have a negative sign. It can be seen from Table 2 that only for the thickness combination according to the invention with Ag2>Ag1>Ag3, 1.0>Ag1/Ag3 and 1.2<Ag2/Ag3<2 both at a viewing angle of 8 and at a viewing angle of 60, the desired blue reflection color is achieved. In this color range, blue tones, which have a particularly high level of customer acceptance, are obtained.

[0130] Values for a*R 60 between 5.0 and 0 and for b*R 60 also between 8.0 and 0 are particularly advantageous.

[0131] FIG. 5 depicts an exemplary embodiment of the method according to the invention referencing a flow chart comprising the following steps. [0132] I Providing an outer pane 1, an inner pane 2, and at least one thermoplastic film to form the thermoplastic intermediate layer 3; [0133] II Applying a sun shading coating 4 according to the invention to the inner surface II of the outer pane 1 or to the outer surface III of the inner pane 2, for example, by means of cathodic sputtering; [0134] III Optionally: Applying bus bars on the sun shading coating 4; [0135] IV Joining the inner surface II of the outer pane 1 and the outer surface III of the inner pane 2 via the thermoplastic intermediate layer 3 to form a composite pane 100.

[0136] In one embodiment, glass panes are used as the outer pane 1 and as the inner pane 2. In a preferred embodiment of the method, the sun shading coating 4 having the at least three functional silver layers Ag1, Ag 2, and Ag3 and the at least four dielectric modules M1, M2, M3 and M4 is applied on the outer surface III of the inner pane 2, preferably by means of magnetron-enhanced cathodic sputtering. If heating of the pane via the sun shading coating 4 is provided, bus bars are provided on the sun shading coating 4 prior to lamination of the pane as well as electrical connection cables that enable electrical contacting of the coating. The joining of the outer pane 1 and the inner pane 2 via the intermediate layer 3 to form the composite glass is preferably done after the sun shading coating 4 has been applied.

LIST OF REFERENCE CHARACTERS

[0137] 1 outer pane [0138] 2 inner pane [0139] 3 thermoplastic intermediate layer [0140] 3a first thermoplastic film [0141] 3b second thermoplastic film [0142] 4 sun shading coating [0143] 5 carrier film [0144] I outer surface of 1 [0145] II inner surface of 1 [0146] III outer surface of 2 [0147] IV inner surface of 2 [0148] Ag1 first silver layer [0149] Ag2 second silver layer [0150] Ag3 third silver layer [0151] M1 first dielectric module [0152] M2 second dielectric module [0153] M3 third dielectric module [0154] M4 fourth dielectric module [0155] B blocking layer [0156] B1 first blocking layer [0157] B2 second blocking layer [0158] B3 third blocking layer