CN209242941U - double silver glass - Google Patents

Abstract

The embodiment of the utility model discloses a double-silver glass, which comprises a glass substrate and a first composite dielectric layer, a first seed layer, a first functional layer, a first protective layer, a second dielectric layer, and a second dielectric layer sequentially located on the glass substrate. Two sublayers, a second functional layer, a second protective layer, and a third composite dielectric layer, wherein the first composite dielectric layer includes a first lower dielectric layer, a first middle layer, a first upper dielectric layer, a first The lower sub-dielectric layer is adjacent to the glass substrate, the first upper sub-dielectric layer is adjacent to the first seed layer, the first middle layer is located between the first lower sub-dielectric layer and the first upper sub-dielectric layer, and the third composite dielectric layer Including the third lower sub-dielectric layer, the third middle layer, the third upper sub-dielectric layer, the third lower sub-dielectric layer is adjacent to the second protective layer, the third middle layer is located between the third lower sub-dielectric layer and the third upper sub-dielectric layer between, and the first intermediate layer and the third intermediate layer include a metal layer. The double-silver glass can improve its optical performance after tempering.

Description

double silver glass

technical field

The utility model relates to an energy-saving glass, in particular to a double-silver glass.

Background technique

With the implementation of national energy conservation and emission reduction policies and people's awareness of low-carbon environmental protection, energy-saving glass represented by low-emissivity glass is more and more widely used in doors, windows and glass curtain walls. In the low-e glass family, double-silver low-e glass with excellent energy-saving performance has been widely used. However, the optical performance of the existing double-silver low-emissivity glass still has certain deficiencies, so its optical performance needs to be further improved to meet higher requirements.

Utility model content

In view of the above problems, embodiments of the present utility model provide a double-silver glass, which can improve its optical performance.

The embodiment of the utility model provides a double-silver glass, which includes a glass substrate. The double-silver glass also includes a first composite dielectric layer, a first seed layer, a first functional layer, and a first protection layer sequentially located on the glass substrate. layer, the second dielectric layer, the second seed layer, the second functional layer, the second protective layer, and the third composite dielectric layer, wherein the first composite dielectric layer includes the first lower dielectric layer, the first intermediate layer , a first upper sub-dielectric layer, the first lower sub-dielectric layer is adjacent to the glass substrate, the first upper sub-dielectric layer is adjacent to the first seed layer, and the first intermediate layer is located at the Between the first lower sub-dielectric layer and the first upper sub-dielectric layer, the third composite dielectric layer includes a third lower sub-dielectric layer, a third middle layer, a third upper sub-dielectric layer, and the third The lower sub-dielectric layer is adjacent to the second protective layer, the third intermediate layer is located between the third lower sub-dielectric layer and the third upper sub-dielectric layer, and the first intermediate layer, the first The second intermediate layer and the third intermediate layer comprise metal layers.

In one embodiment of the present utility model, the metal layer contains a single substance or an alloy of niobium, iron, tantalum, nickel, chromium or zirconium.

In one embodiment of the present invention, the first lower dielectric layer, the first upper dielectric layer, the third lower dielectric layer and the third upper dielectric layer respectively contain metal or non-metal oxides or nitrides.

In one embodiment of the present invention, the first lower sub-dielectric layer, the first upper sub-dielectric layer, the third lower sub-dielectric layer and the third upper sub-dielectric layer respectively comprise silicon nitride, Zinc tin oxide, zinc aluminum oxide, silicon oxide, titanium oxide or niobium oxide.

In one embodiment of the present invention, the first protective layer and the second protective layer respectively contain nickel-chromium alloy or nickel-chromium oxide, and the first seed layer and the second seed layer respectively contain oxide Zinc, zinc aluminum oxide or zinc tin oxide.

In one embodiment of the present invention, the double-silver glass further includes a first heat-stable dielectric layer between the first protective layer and the second dielectric layer and/or a thermally stable dielectric layer located between the second protective layer and the second heat-stable medium layer between the third composite medium layer.

In one embodiment of the present invention, the thicknesses of the first lower sub-dielectric layer and the first upper sub-dielectric layer are 0-80 nm respectively, and the thicknesses of the third lower sub-dielectric layer and the third upper sub-dielectric layer are The thicknesses of the layers are 0 to 100 nm, respectively.

In one embodiment of the present invention, the thickness of the first seed layer, the first protective layer, the second seed layer or the second protective layer is 0-20 nm.

In one embodiment of the present utility model, the first functional layer and the second functional layer respectively contain silver or copper-silver alloy, and the thicknesses of the first functional layer and the second functional layer are respectively 0 to 40nm.

The above-mentioned technical solution can have the following advantages: the double-silver glass provided by the embodiment of the utility model adopts a unique double-composite dielectric layer film structure, which can adjust the absorption intensity of each layer corresponding to different spectral bands, and improve the tempered double-silver glass. optical properties.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention , for those skilled in the art, other drawings can also be obtained according to these drawings on the premise of not paying creative work.

Fig. 1 is the structural representation of a kind of double silver glass that the utility model embodiment provides;

Fig. 2 is a further structural schematic diagram of the double silver glass in Fig. 1 .

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without creative efforts belong to the protection scope of the present utility model.

As shown in FIG. 1 , an embodiment of the present invention provides a double-silver glass 200, which includes a glass substrate 10 and a first composite dielectric layer 11, a first seed layer 12, and a first functional layer sequentially formed on the glass substrate 10. 13. The first protective layer 14 , the second dielectric layer 15 , the second seed layer 16 , the second functional layer 17 , the second protective layer 18 and the third composite dielectric layer 19 . The first composite dielectric layer 11, the first seed layer 12, the first functional layer 13, the first protective layer 14, the second dielectric layer 15, the second seed layer 16, the second functional layer 17, the second protective layer 18 and the first All three composite dielectric layers 19 can be made of solid materials.

Wherein, the glass substrate 10 can be ordinary glass, colored glass, ultra-clear glass or other glass, and its thickness can be 3-10 millimeters (mm), preferably 6 mm.

The first composite dielectric layer 11 includes, for example, a first lower sub-dielectric layer 111 , a first middle layer 112 and a first upper sub-dielectric layer 113 . The first lower sub-dielectric layer 111 is adjacent to the glass substrate 10, the first upper sub-dielectric layer 113 is adjacent to the first seed layer 12, and the first intermediate layer 112 is located between the first lower sub-dielectric layer 111 and the first upper sub-dielectric layer. Between 113. The third composite dielectric layer 19 includes, for example, a third lower sub-dielectric layer 191 , a third middle layer 192 and a third upper sub-dielectric layer 193 . The third lower sub-dielectric layer 191 is adjacent to the second protection layer 18 , the third upper sub-dielectric layer 193 is the top layer, and the third middle layer 192 is located between the third lower sub-dielectric layer 191 and the third upper sub-dielectric layer 193 .

The first lower sub-dielectric layer 111, the first upper sub-dielectric layer 113, the third lower sub-dielectric layer 191, and the third upper sub-dielectric layer 193, for example, respectively include metal or non-metallic oxides and nitrides, such as silicon nitride (Si ₃ N ₄ ), zinc tin oxide (ZnSnO _x ), zinc aluminum oxide (AZO), silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ) or niobium oxide (Nb ₂ O ₅ ), etc. The thicknesses of the first lower sub-dielectric layer 111 and the first upper sub-dielectric layer 113 are 0-80 nm respectively. The thicknesses of the third lower sub-dielectric layer 191 and the third upper sub-dielectric layer 193 are 0-100 nm respectively. The first intermediate layer 112 and the third intermediate layer 192 are respectively metal layers. Specifically, the first intermediate layer 112 and the third intermediate layer 192 respectively contain, for example, a single substance of niobium, iron, tantalum, nickel, chromium or zirconium or an alloy such as nickel-chromium alloy (NiCr). The thicknesses of the first intermediate layer 112 and the third intermediate layer 192 are 0-30 nm, respectively. In this way, the toughened double-silver Low-E product with double-composite dielectric layer film structure can freely adjust the absorption intensity of each layer to improve the optical performance of double-silver glass.

The second dielectric layer 15 includes, for example, metal or non-metal oxides or nitrides, such as silicon nitride (Si ₃ N ₄ ), zinc tin oxide (ZnSnO _x ), zinc aluminum oxide (AZO), silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ) or niobium oxide (Nb ₂ O ₅ ), etc. The thickness of the second dielectric layer 15 is 0-100 nm.

Furthermore, the first seed layer 12, the first protective layer 14, the second seed layer 16 and the second protective layer 18 contain, for example, a metal, a metal alloy or a metal alloy oxide, such as nickel-chromium alloy (NiCr) or nickel-chromium oxide, respectively. (NiCrO _x ) and so on. Further, the first seed layer 12 and the second seed layer 16 respectively include zinc oxide (ZnO or ZnAlO _x ), zinc aluminum oxide (AZO) or zinc tin oxide (ZnSnO _x ), for example. The thicknesses of the first seed layer 12 , the first protection layer 14 , the second seed layer 16 and the second protection layer 18 are 0-20 nm, respectively.

The first functional layer 13 and the second functional layer 17 contain, for example, silver (Ag) or a copper-silver (AgCu) alloy. The thicknesses of the first functional layer 13 and the second functional layer 17 are respectively 0-40 nm.

In addition, as shown in FIG. 2 , the double silver glass 200 also includes, for example, a first heat-stable dielectric layer 21 between the first protective layer 14 and the second dielectric layer 15 and/or a composite layer between the second protective layer 18 and the third composite layer. The second thermally stable dielectric layer 22 between the third sub-dielectric layer 191 of the dielectric layer 19 . The first thermally stable dielectric layer 21 and the second thermally stable dielectric layer 22 can improve the thermal stability of the double silver glass 200 . Specifically, the first thermally stable dielectric layer 21 and/or the second thermally stable dielectric layer 22 are obtained by sputtering a metal oxide ceramic target, such as zinc aluminum oxide (AZO, ZnAlOx), zinc tin oxide (ZnSnOx), Titanium oxide (TiOx). During the tempering process, the thermally stable medium layer is beneficial to improve the thermal stability of the Low-E film layer and the product, so that the product film layer can better withstand the test of tempering without being damaged. In addition, the use of thermally stable dielectric layer can not only improve the thermal stability of the product, but also improve the optical performance of the product. Furthermore, since oxygen is an important factor affecting the thermal stability of the product, during the film preparation process, the thermally stable dielectric layer is sputtered with a metal oxide ceramic target without adding oxygen or adding less oxygen, which can reduce the flow of oxygen to the adjacent Diffusion of the target site to improve the thermal stability of the product. Usually, the thicknesses of the first thermally stable dielectric layer 21 and the second thermally stable dielectric layer 22 are respectively 0-50 nm.

In summary, all the film layers of the double silver glass 200 provided by the embodiment of the present invention can be made of solid materials, and a unique film structure of double composite dielectric layers is adopted to improve the optical performance of the double silver glass. Compared with the traditional toughened double-silver Low-E (Low-Emissivity, low-emissivity glass) with a single dielectric layer film structure, the toughened double-silver Low-E product with a double-composite dielectric layer film structure can freely adjust each layer The absorption intensity of these different regions corresponds to different spectral bands. According to the different appearance colors required by Low-E, it can be flexibly adjusted to obtain the desired spectral shape. When the appearance color of the glass is guaranteed to be the mainstream appearance color in the market, better visible light transmission color can be obtained. Specifically, the traditional single dielectric layer can be steel double-silver structure, and the film thickness is as follows: glass substrate (6mm)/Si ₃ N ₄ (33.4nm)/ZnO (10.8nm)/Ag (3.3nm)/NiCr (1nm )/Si ₃ N ₄ (74.2nm)/NiCr(2.2nm)/Ag(21.5nm)/NiCr(0.8nm)/Si ₃ N ₄ (49.7nm) double silver glass, the optical test results after tempering are: Visible light transmittance is 48.2%, transmittance color a*: -5.2, b*: 0.6, glass surface reflectance 23.1%, reflection color a*: -1.9, b*: -14.9, outdoor observation is dark blue, indoor is yellow-green. However, the embodiment of the utility model provides a double-composite dielectric layer with a steel-double-silver structure, and the film thickness is as follows: glass substrate (6mm)/Si ₃ N ₄ (10nm)/NiCr (2nm)/Si ₃ N ₄ (37.3nm)/NiCr(0.8nm)/Ag(10nm)/NiCr(0.8nm)/Si ₃ N ₄ (88nm)/NiCr(2nm)/Ag(16.7nm)/NiCr(2nm)/Si ₃ N ₄ (15nm)/NiCr(2nm)/Si ₃ N ₄ (15nm) double silver glass, the optical test results after tempering treatment are: visible light transmittance 49%, transmission color a*:-2.82, b*:- 0.9, the reflectance of the glass surface is 15.55%, the reflection color a*:-1.22, b*:-4.5, the outdoor observation is gray, and the indoor observation is light green. It can be seen that, regardless of outdoor observation or indoor observation, the color of the temperable double-silver Low-E with double-composite dielectric layer film structure provided by the embodiment of the present invention is more neutral, natural and comfortable. In addition, both the first functional layer 13 and the second functional layer 17 are silver layers, which can additionally reflect infrared heat and prevent heat from passing through. Furthermore, because the double-silver glass 200 can be produced by only using the magnetron reactive sputtering deposition method to form each layer, it can avoid multiple entry and exit of the coating equipment during the production process, simplify the production process, and thereby reduce production costs. Increase productivity.

In addition, another embodiment of the present invention also provides a method for preparing double-silver glass to prepare the above-mentioned double-silver glass 200 . First, a glass substrate 10 is provided. Generally, the glass substrate 10 needs to be cleaned, dried, and then transferred to the coating area of the vacuum chamber. Next, the first composite dielectric layer 11, the first seed layer 12, the first functional layer 13, the first protective layer 14, the second dielectric layer 15, the second The seed layer 16 , the second functional layer 17 , the second protection layer 18 and the third composite dielectric layer 19 . Each layer is formed by magnetron sputtering coating deposition at room temperature, but after the deposition of each layer, the glass substrate 10 formed with each layer needs to be post-treated. The post-processing method includes, for example, tempering the glass substrate 10 formed with various layers, wherein the temperature of the tempering treatment is 650-700° C. for about 1-10 minutes; or it includes annealing the glass substrate 10 formed with various layers. treatment, wherein the annealing temperature is 400-650° C., and the annealing time is 20 minutes to 2 hours. The preparation process of the double-silver glass 200 will be described in detail below through two specific examples.

Specific embodiment 1

A kind of double silver glass, its film layer structure from the glass substrate to the outside is: Si ₃ N ₄ (10nm)/NiCr(2nm)/Si ₃ N ₄ (37.3nm)/NiCr(0.8nm)/Ag(10nm) /NiCr(0.8nm)/Si ₃ N ₄ (88nm)/NiCr(2nm)/Ag(16.7nm)/NiCr(2nm)/Si ₃ N ₄ (15nm)/NiCr(2nm)/Si ₃ N ₄ (15nm ).

The method for preparing this double-silver glass is as follows:

(1) The glass substrate is cleaned and dried, and placed in a vacuum sputtering area;

(2) Deposit the Si ₃ N ₄ layer on the glass substrate by means of magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature;

(3) The NiCr layer is deposited on the Si ₃ N ₄ layer by magnetron sputtering. The target material used is a metal NiCr planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, and the process gas is pure argon. deposition at room temperature;

(4) The Si ₃ N ₄ layer is deposited on the NiCr layer by magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature;

(5) The NiCr layer is deposited on the Si ₃ N ₄ layer by magnetron sputtering, the target used is a metal NiCr planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, and the process gas is pure argon. deposition at room temperature;

(6) Deposit the Ag layer on the NiCr layer by means of magnetron sputtering, the target used is an Ag planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, the process gas is pure argon, and it is deposited at room temperature ;

(7) The NiCr layer is deposited on the Ag layer by magnetron sputtering. The target used is a metal NiCr planar target. deposition;

(8) The Si ₃ N ₄ layer is deposited on the NiCr layer by magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature;

(9) The NiCr layer is deposited on the Si ₃ N ₄ layer by magnetron sputtering, the target used is a metal NiCr planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, and the process gas is pure argon. deposition at room temperature;

(10) The Ag layer is deposited on the NiCr layer by magnetron sputtering, the target used is an Ag planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, the process gas is pure argon, and it is deposited at room temperature ;

(11) The NiCr layer is deposited on the Ag layer by magnetron sputtering, the target used is a metal NiCr planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, and the process gas is pure argon. deposition;

(12) Deposit the Si ₃ N ₄ layer on the NiCr layer by magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature.

(13) The NiCr layer is deposited on the Ag layer by magnetron sputtering, the target used is a metal NiCr planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, and the process gas is pure argon. deposition;

(14) Deposit the Si ₃ N ₄ layer on the NiCr layer by magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature.

Specific embodiment 2

A kind of double silver glass, its film layer structure from the glass substrate to the outside is: Si ₃ N ₄ (27.4nm)/NiCr(1nm)/Si ₃ N ₄ (10nm)/ZnAlO _x (8.1nm)/Ag(10nm )/NiCr(1nm)/Si ₃ N ₄ (71.1nm)/ZnAlO _x (8nm)/Ag(15nm)/NiCr(1nm)/AZO(10nm)/Si ₃ N ₄ (10nm)/NiCr(1nm)/ Si3N4 _{( 23nm} ).

The method for preparing this double-silver glass is as follows:

(1) The glass substrate is cleaned and dried, and placed in a vacuum sputtering area;

(2) Deposit the Si ₃ N ₄ layer on the glass substrate by means of magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature;

(3) The NiCr layer is deposited on the Si ₃ N ₄ layer by magnetron sputtering. The target material used is a metal NiCr planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, and the process gas is pure argon. deposition at room temperature;

(4) The Si ₃ N ₄ layer is deposited on the NiCr layer by magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature;

(5) Deposit the ZnAlO _x layer on the Si ₃ N ₄ layer by magnetron sputtering, the target used is a ZnAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixture of argon and oxygen gas, deposited at room temperature;

(6) The Ag layer is deposited by magnetron sputtering on the ZnAlO _x layer. The target used is an Ag planar target. deposition.

(7) The NiCr layer is deposited on the Ag layer by magnetron sputtering. The target used is a metal NiCr planar target. deposition;

(8) The Si ₃ N ₄ layer is deposited on the NiCr layer by magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature;

(9) Deposit the ZnAlO _x layer on the Si ₃ N ₄ layer by magnetron sputtering, the target used is a ZnAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixture of argon and oxygen gas, deposited at room temperature;

(10) The Ag layer is deposited on the ZnAlO _x layer by magnetron sputtering. The target used is an Ag planar target, the power supply is a DC plus pulse power supply, and the power is 1-10KW. deposition.

(11) The NiCr layer is deposited on the Ag layer by magnetron sputtering, the target used is a metal NiCr planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, and the process gas is pure argon. deposition;

(12) The AZO layer is deposited on the NiCr layer by magnetron sputtering, the target used is a ceramic AZO rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is pure argon or argon and oxygen. Mixed gas, deposited at room temperature.

(13) Deposit the Si ₃ N ₄ layer on the AZO layer by magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature.

(14) The NiCr layer is deposited on the Si ₃ N ₄ layer by magnetron sputtering, the target used is a metal NiCr planar target, the power supply is DC plus pulse power supply, the power is 1-10KW, and the process gas is pure argon. deposition at room temperature;

(15) Deposit the Si ₃ N ₄ layer on the NiCr layer by magnetron sputtering, the target used is a SiAl rotating target, the power supply is an intermediate frequency power supply, the power is 10-100KW, and the process gas is a mixed gas of argon and nitrogen , deposited at room temperature.

(16) Tempering the finished glass.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model, and are not intended to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit of the technical solutions of the various embodiments of the present invention. and range.

Claims (9)

1. A double-silver glass, comprising a glass substrate, characterized in that, said double-silver glass also comprises a first composite medium layer, a first seed layer, a first functional layer, and a first protection layer positioned on the glass substrate in turn. layer, the second dielectric layer, the second seed layer, the second functional layer, the second protective layer, and the third composite dielectric layer, wherein the first composite dielectric layer includes the first lower dielectric layer, the first intermediate layer , a first upper sub-dielectric layer, the first lower sub-dielectric layer is adjacent to the glass substrate, the first upper sub-dielectric layer is adjacent to the first seed layer, and the first intermediate layer is located at the Between the first lower sub-dielectric layer and the first upper sub-dielectric layer, the third composite dielectric layer includes a third lower sub-dielectric layer, a third middle layer, a third upper sub-dielectric layer, and the third The lower sub-dielectric layer is adjacent to the second protection layer, the third intermediate layer is located between the third lower sub-dielectric layer and the third upper sub-dielectric layer, and the first intermediate layer and the third The three intermediate layers contain metal layers. 2. The double-silver glass according to claim 1, wherein the metal layer comprises a single substance or an alloy of niobium, iron, tantalum, nickel, chromium or zirconium. 3. The double-silver glass according to claim 1, wherein the first lower dielectric layer, the first upper dielectric layer, the third lower dielectric layer, and the third upper dielectric layer The layers comprise oxides or nitrides of metals or metalloids, respectively. 4. The double-silver glass according to claim 3, characterized in that, the first lower sub-dielectric layer, the first upper sub-dielectric layer, the third lower sub-dielectric layer and the third upper sub-dielectric layer The layers each contain silicon nitride, zinc tin oxide, zinc aluminum oxide, silicon oxide, titanium oxide or niobium oxide. 5. double silver glass as claimed in claim 1, is characterized in that, described first protection layer and described second protection layer comprise nickel-chromium alloy or nickel-chromium oxide respectively, and described first seed layer and described The second seed layer contains zinc oxide, zinc aluminum oxide or zinc tin oxide, respectively. 6. The double-silver glass according to claim 1, characterized in that, the double-silver glass further comprises a first thermally stable medium layer and/or a layer between the first protective layer and the second medium layer A second thermally stable dielectric layer located between the second protective layer and the third composite dielectric layer. 7. The double-silver glass according to claim 1, wherein the thicknesses of the first lower sub-dielectric layer and the first upper sub-dielectric layer are respectively 0 to 80 nm, and the third lower sub-dielectric layer and The thicknesses of the third upper sub-dielectric layers are respectively 0-100 nm. 8. The double-silver glass according to claim 1, wherein the thickness of the first seed layer, the first protective layer, the second seed layer or the second protective layer is 0-20nm . 9. double silver glass as claimed in claim 1, is characterized in that, described first functional layer and described second functional layer comprise silver or copper-silver alloy respectively, and described first functional layer and described second functional layer The thicknesses of the layers are 0 to 40 nm, respectively.