Composite Insulating Material for Cabinet Current Transformer and Its Preparation Method

Abstract

The present invention discloses a composite insulating material for a cabinet-type current transformer, comprising: a substrate; a Cu layer on the substrate; a CuAl layer on the Cu layer; a first Al 2‑x Gd x O3 layer; a second Al 2‑x Gd x O3 layer on the first Al 2‑y Sm y O3 layer; a third Al 2‑ y Sm y O3 layer on the Al 2‑z Gd z O3 layer; and an Al2O3 layer on the second Al 2‑ z Gd z O3 layer. Through the design of the film layer stacking structure and process parameters of the composite insulating material of the present invention, the outermost aluminum oxide layer in the composite film layer of the present invention can be in an amorphous state, which greatly improves the antioxidant capacity of the aluminum oxide film layer. In addition, the composite film layer of the present invention itself also has antioxidant capacity and can also improve the antioxidant property of epoxy resin.

Description

Technical Field

[0001] The present invention relates to the technical field of layered materials, and particularly to a composite insulating material for a cabinet-type current transformer and a preparation method thereof. Background Art

[0002] Cabinet-type current transformers are core devices used for current measurement, protection, and control in power systems. They are usually integrated in distribution cabinets, ring main units, or switch cabinets, and play a key role in converting high-voltage or large-current signals into low-voltage and small-current signals. There are a large number of insulating materials in cabinet-type current transformers. A main insulating material is epoxy resin. As is well known, cabinet-type current transformers may operate in high-temperature and high-humidity working environments. Epoxy resin is prone to oxidation reactions in high-temperature and high-humidity environments. The mechanical properties of oxidized epoxy resin decline, and the material itself cracks, resulting in material failure. The traditional method is to enhance the oxidation resistance of epoxy resin by using additives, but this method has limited ability to improve the oxidation resistance of epoxy resin. At present, it has been found that the oxidation resistance of epoxy resin can be improved by plating aluminum oxide on the surface of epoxy resin. However, when plating aluminum oxide, crystalline-phase aluminum oxide is likely to appear in the film layer, which limits the improvement range of the oxidation resistance of the aluminum oxide film for epoxy resin. Summary of the Invention

[0003] The present invention provides a composite insulating material for a cabinet-type current transformer. Through the design of the film layer stacking structure and process parameters of the composite insulating material of the present invention, the outermost aluminum oxide layer in the composite film layer of the present invention can be in an amorphous state, which greatly improves the oxidation resistance of the aluminum oxide film layer. In addition, the composite film layer of the present invention itself also has oxidation resistance and can also improve the oxidation resistance of epoxy resin.

[0004] The present invention provides a composite insulating material for a cabinet-type current transformer, wherein the composite insulating material includes:

[0005] A substrate;

[0006] A Cu layer on the substrate;

[0007] A CuAl layer on the Cu layer;

[0008] A first Al 2-x Gd x O3 layer on the CuAl layer;

[0009] An Al 2-x Gd x O3 layer on the first Al 2-y Sm y O3 layer on the GdO3 layer;

[0010] On the first Al 2-y Sm y O3 layer, the second Al 2-z Gd z O3 layer; and

[0011] On the second Al 2-z Gd z Al2O3 layer.

[0012] In a preferred embodiment, the first Al 2-x Gd x O3 layer is formed on the CuAl layer by the following method:

[0013] Deposit the first Al 2-x Gd x O3 layer on the CuAl layer by magnetron sputtering, where the sputtering target is an Al 2-x Gd x O3 target, where x = 0.05 - 0.1, the power supply type is a radio frequency power supply, the sputtering power is 50 - 100 W, the sputtering voltage is 200 - 300 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

[0014] In a preferred embodiment, the Al 2-y Sm y O3 layer is formed on the first Al 2-x Gd x O3 layer by the following method:

[0015] Deposit the Al 2-x Gd x O3 layer on the first Al 2-y Sm y O3 layer by magnetron sputtering, where the sputtering target is an Al 2- y Sm y O3 target, where y = 0.02 - 0.04, the power supply type is a radio frequency power supply, the sputtering power is 60 - 120 W, the sputtering voltage is 200 - 300 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

[0016] In a preferred embodiment, the second Al 2-z Gd z O3 layer is formed on the Al 2-y Sm y O3 layer by the following method:

[0017] Deposit on the Al 2-y Sm yDeposit a second Al on the O3 layer 2-z Gd z O3 layer, wherein the sputtering target is Al 2- z Gd z O3 target, where z = 0.12 - 0.16, the power supply type is a radio frequency power supply, the sputtering power is 60 - 120 W, the sputtering voltage is 350 - 500 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

[0018] In a preferred embodiment, the Al2O3 layer is formed on the second Al 2-z Gd z O3 layer as follows:

[0019] Deposit the Al2O3 layer on the second Al 2-z Gd z O3 layer by magnetron sputtering, wherein the sputtering target is an Al2O3 target, the power supply type is a radio frequency power supply, the sputtering power is 50 - 100 W, the sputtering voltage is 200 - 300 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 130 - 150 °C.

[0020] In a preferred embodiment, the thickness of the first Al 2-x Gd x O3 layer is 20 - 30 nm, the thickness of the Al 2-y Sm y O3 layer is 20 - 30 nm, the thickness of the second Al 2-z Gd z O3 layer is 30 - 40 nm, and the thickness of the Al2O3 layer is 200 - 300 nm.

[0021] The present invention provides a method for preparing a composite insulating material for a cabinet - type current transformer, comprising:

[0022] Form a Cu layer on a substrate;

[0023] Form a CuAl layer on the Cu layer;

[0024] Form a first Al 2-x Gd x O3 layer on the CuAl layer;

[0025] Form an Al 2-x Gd x O3 layer on the first Al 2-y Sm y O3 layer;

[0026] On the Al 2-y Sm yThe second Al 2-z Gd z O3 layer is formed on; and

[0027] An Al2O3 layer is formed on the second Al 2-z Gd z O3 layer.

[0028] In a preferred embodiment, the first Al 2-x Gd x O3 layer is formed on the CuAl layer and includes:

[0029] The first Al 2-x Gd x O3 layer is deposited on the CuAl layer by magnetron sputtering, wherein the sputtering target is an Al 2-x Gd x O3 target, where x = 0.05 - 0.1, the power supply type is a radio frequency power supply, the sputtering power is 50 - 100 W, the sputtering voltage is 200 - 300 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

[0030] In a preferred embodiment, an Al 2-x Gd x O3 layer is formed on the first Al 2-y Sm y O3 layer and includes:

[0031] The Al 2-x Gd x O3 layer is deposited on the first Al 2-y Sm y O3 layer by magnetron sputtering, wherein the sputtering target is an Al 2- y Sm y O3 target, where y = 0.02 - 0.04, the power supply type is a radio frequency power supply, the sputtering power is 60 - 120 W, the sputtering voltage is 200 - 300 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

[0032] In a preferred embodiment, the second Al 2-y Sm y O3 layer is formed on the Al 2-z Gd z O3 layer and includes:

[0033] The second Al 2-y Sm y O3 layer is deposited on the Al 2-z Gd z O3 layer by magnetron sputtering, wherein the sputtering target is an Al 2-z Gd z A GdO3 target, where z = 0.12 - 0.16, the power supply type is a radio frequency power supply, the sputtering power is 60 - 120 W, the sputtering voltage is 350 - 500 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

[0034] Compared with the prior art, the present invention has the following advantages. Through the design of the film layer stacking structure and process parameters of the composite insulating material of the present invention, the outermost aluminum oxide layer in the composite film layer of the present invention can be in an amorphous state, which greatly improves the antioxidant ability of the aluminum oxide film layer. In addition, the composite film layer of the present invention itself also has antioxidant ability and can also improve the antioxidant property of epoxy resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic diagram of the film layer structure of an embodiment of the present invention.

[0036] Figure 2 is an XRD pattern of a position of a sample prepared through an embodiment of the present invention.

[0037] Figure 3 is an XRD pattern of another position of a sample prepared through an embodiment of the present invention.

[0038] Figure 4 is a TEM photo of a comparative example. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0040] Figure 1 is a schematic diagram of the film layer structure of an embodiment of the present invention. As shown in the figure, the composite insulating material for a cabinet-type current transformer of the present invention includes: a substrate, a Cu layer, a CuAl layer, a first Al 2-x Gd x O3 layer, an Al 2-y Sm y O3 layer, a second Al 2- z Gd z O3 layer, and an Al2O3 layer. Among them, in one example, the substrate can be an epoxy resin board. Before depositing the Cu layer, the substrate can be subjected to well-known pretreatment, such as polishing and cleaning the surface of the substrate.

[0041] Example 1

[0042] A composite insulating material for a cabinet-type current transformer is provided, including: a substrate; a Cu layer on the substrate; a CuAl layer on the Cu layer; a first Al 2-x Gd x O3 layer; a first Al 2-x Gd x O3 layer on the first Al 2-y Sm y O3 layer; a second Al 2-y Sm y O3 layer on the Al 2-z Gd z O3 layer; and an Al2O3 layer on the second Al 2-z Gd z O3 layer. In one example, the substrate can be an epoxy resin board. Before depositing the Cu layer, the substrate can be subjected to well-known pretreatment, such as polishing and cleaning the surface of the substrate. In one example, the thickness of the Cu layer can be 10 - 20 nm (10 nm is taken for each embodiment and comparative example of the present invention). The main function of the Cu layer is that the Cu film has good film-forming properties on the surface of the epoxy resin and is easy to form a continuous and crack-free film layer on the surface of the epoxy resin. Therefore, the Cu film can be used as the deposition basis for other subsequent film layers. The magnetron sputtering process of the Cu layer itself is as follows: the sputtering target is a Cu target, where the power type is a radio frequency power supply, the sputtering power is 100 W, the sputtering voltage is 400 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 100 °C. The main function of the CuAl layer is a transition layer because the lattice parameters of the Cu and the Al 2-x Gd x O3 layer differ greatly. If the Al 2-x Gd x O3 layer is directly plated on the Cu layer, it may cause excessive interfacial stress and lead to film layer rupture. The plating process of the CuAl layer can be the same as that of the Cu layer. The plating processes of the Cu layer and the CuAl layer themselves have little influence on the effect of the present invention. In subsequent embodiments and comparative examples, if there is no contrary indication, the plating processes of the Cu layer and the CuAl layer are the same as those in Example 1.

[0043] The first Al 2-x Gd x O3 layer is formed on the CuAl layer by the following method: depositing the first Al 2-x Gd x O3 layer on the CuAl layer by magnetron sputtering, where the sputtering target is Al 2-x Gd xO3 target, where x = 0.05, the power supply type is radio frequency power supply, the sputtering power is 50 W, the sputtering voltage is 200 V, the argon gas flow rate is 20 sccm, and the sputtering temperature is 80 °C. In one example, Al 2-x Gd x The O3 target can be directly purchased as a finished product from non-ferrous metal companies. Such targets are generally formed by powder metallurgy.

[0044] Al 2-y Sm y The O3 layer is formed on the first Al 2-x Gd x O3 layer by the following method: depositing the Al 2-x Gd x O3 layer on the first Al 2-y Sm y O3 layer by magnetron sputtering, where the sputtering target is the Al 2-y Sm y O3 target, where y = 0.02, the power supply type is radio frequency power supply, the sputtering power is 60 W, the sputtering voltage is 200 V, the argon gas flow rate is 20 sccm, and the sputtering temperature is 80 °C. In one example, Al 2-y Sm y The O3 target can be directly purchased as a finished product from non-ferrous metal companies. Such targets are generally formed by powder metallurgy.

[0045] The second Al 2-z Gd z O3 layer is formed on the Al 2-y Sm y O3 layer by the following method: depositing the second Al 2-y Sm y O3 layer on the Al 2-z Gd z O3 layer by magnetron sputtering, where the sputtering target is the Al 2-z Gd z O3 target, where z = 0.12, the power supply type is radio frequency power supply, the sputtering power is 60 W, the sputtering voltage is 350 V, the argon gas flow rate is 20 sccm, and the sputtering temperature is 80 °C. In one example, Al 2-z Gd z The O3 target can be directly purchased as a finished product from non-ferrous metal companies. Such targets are generally formed by powder metallurgy.

[0046] The Al2O3 layer is formed on the second Al 2-z Gd z O3 layer by the following method: depositing the second Al 2-z Gd zAn Al2O3 layer is deposited on the O3 layer. Among them, the sputtering target is an Al2O3 target. Among them, the power supply type is a radio frequency power supply, the sputtering power is 50 W, the sputtering voltage is 200 V, the argon gas flow rate is 20 sccm, and the sputtering temperature is 130 °C. In the prior art CN218730955U, a scheme for forming amorphous Al2O3 by radio frequency sputtering is proposed, but this prior art does not disclose what process parameters can be used to form amorphous Al2O3. In fact, the prior art generally uses the method of atomic layer deposition to form amorphous Al2O3 (for example, refer to CN108847443A). This is because the deposition rate of this deposition method is slow and it is easy to control the crystal form of Al2O3. However, the magnetron sputtering itself has a relatively fast deposition rate, and it is difficult to control the crystal form of Al2O3 during the deposition process, which easily leads to the formation of crystalline Al2O3. In other words, it is difficult to form a large-area Al2O3 film by magnetron sputtering deposition. If the deposition rate is reduced to achieve the formation of a large-area Al2O3 film by magnetron sputtering deposition, the slower deposition rate will offset the advantages of magnetron sputtering coating. The reason why the outermost Al2O3 film in the present invention is required to be an amorphous Al2O3 film is that the crystalline Al2O3 film has many grain boundaries due to the existence of more grain boundaries. The materials in the grain boundaries are generally complex compounds that deviate from the chemical ratio of Al2O3, which leads to a relatively fast corrosion rate of oxygen, water vapor and other molecules on the grain boundaries. At this time, oxygen, water vapor and other molecules are easy to penetrate the Al2O3 film along the grain boundaries. At this time, the protective effect of the Al2O3 film on the epoxy resin disappears, and the improvement effect of the Al2O3 film itself on the oxidation resistance of the epoxy resin is lost. The inventor of the present invention found after research that if an Al2O3 film is formed on some rare earth doped film layers, the Al2O3 film is more likely to form an amorphous state. This may be because the lattice structure of the rare earth doped film layer itself prevents the formation of a crystalline Al2O3 film. Specifically, according to the explanation of crystallization thermodynamics, the necessary condition for crystallization is the formation of crystal nuclei, but the formation of crystal nuclei requires that the Gibbs free energy of forming crystal nuclei is less than 0 (that is, if the Gibbs free energy of forming crystal nuclei is greater than 0, then crystal nuclei cannot be formed without external intervention). The Gibbs free energy of forming crystal nuclei is related to the interaction of the electron clouds of the Al2O3 film and the rare earth doped film layer. Because crystallization is essentially a redistribution of the overlap of electron clouds, if the energy of the overlap of electron clouds after crystallization is lower than the energy of the overlap of electron clouds in the amorphous state, then crystal nuclei will appear, otherwise crystal nuclei will not appear. The lattice structure of the rare earth doped film layer itself (and the specific electron cloud shape brought by it) may make the energy of the overlap of the electron clouds of the Al2O3 film and the rare earth doped film layer in the amorphous state lower. Therefore, the lattice structure of the rare earth doped film layer itself prevents the formation of a crystalline Al2O3 film. It should be understood that the above explanation of the principle is only a possible explanation for the experimental phenomenon, and other explanations for this experimental phenomenon may also be reasonable.

[0047] First Al 2-x Gd x The thickness of the GdO3 layer is 20 nm, Al 2-y Sm y The thickness of the SmO3 layer is 20 nm, second Al 2-z Gd z The thickness of the GdO3 layer is 30 nm, and the thickness of the Al2O3 layer is 200 nm.

[0048] To verify that the method of the present invention can form an amorphous Al2O3 film, XRD experiments were carried out on the samples, Figure 2 and Figure 3 are the obtained XRD patterns. Figure 2 and Figure 3 The preparation method of the samples of and is as follows: First, the composite insulating material of Example 1 was cut into two pieces by mechanical cutting. Each piece of the composite insulating material was then processed as follows: First, the composite insulating material was thinned to less than 0.2 mm by mechanical means such as grinding (it should be understood that the material on the substrate side should be ground off), and then the composite insulating material was ion-thinned using an ion etching machine until the substrate, Cu layer, CuAl layer, first Al 2-x Gd x O3 layer, Al 2-y Sm y O3 layer, second Al 2-z Gd z O3 layer were all ground or etched away. At this time, a part of the amorphous Al2O3 film was separated alone. At this time, the XRD test was carried out on this sample. The test results of one sample are shown in Figure 2 and the test results of the other sample are shown in Figure 3 . It can be clearly seen from the figure that the XRD diffraction pattern presents an obvious amorphous diffraction envelope and there are no any crystalline diffraction peaks. Therefore, the method of the present invention can form an amorphous Al2O3 film.

[0049] The oxidation resistance test of Example 1 was carried out. The test method is as follows: First, the original tensile strength of the just-prepared composite insulating material was tested. Then, the side of the epoxy resin coated with the film layer was contacted with potassium permanganate, and the temperature was maintained at 70 °C and the oxidation time was 1000 h. Then, the composite insulating material was taken out, and the remaining tensile strength of the composite insulating material was tested. Finally, the ratio of ((original tensile strength - remaining tensile strength) / original tensile strength) was calculated and defined as the tensile strength change rate ratio. This ratio reflects the degree of oxidation of the epoxy resin. The tensile strength change rate ratio of the sample of Example 1 was 6%.

[0050] Example 2

[0051] A composite insulating material for a cabinet-type current transformer is provided, including: a substrate; a Cu layer on the substrate; a CuAl layer on the Cu layer; a first Al 2-x Gd x O3 layer; a first Al 2-x Gd x O3 layer on the Gd 2-y Sm y O3 layer; a second Al 2-y Sm y O3 layer on the Sm 2-z Gd z O3 layer; and an Al2O3 layer on the second Al 2-z Gd z O3 layer.

[0052] The first Al 2-x Gd x O3 layer is formed on the CuAl layer by the following method: depositing the first Al 2-x Gd x O3 layer on the CuAl layer by magnetron sputtering, where the sputtering target is an Al 2-x Gd x O3 target, where x = 0.1, where the power supply type is a radio frequency power supply, the sputtering power is 100 W, the sputtering voltage is 300 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 100 °C.

[0053] The Al 2-y Sm y O3 layer is formed on the first Al 2-x Gd x O3 layer by the following method: depositing the Al 2-x Gd x O3 layer on the first Al 2-y Sm y O3 layer by magnetron sputtering, where the sputtering target is an Al 2-y Sm y O3 target, where y = 0.04, where the power supply type is a radio frequency power supply, the sputtering power is 120 W, the sputtering voltage is 300 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 100 °C.

[0054] The second Al 2-z Gd z O3 layer is formed on the Al 2-y Sm y O3 layer by the following method: depositing the second Al 2-y Sm y O3 layer on the Al 2-z Gd zO3 layer, where the sputtering target is Al 2-z Gd z O3 target, where z = 0.16, the power supply type is a radio frequency power supply, the sputtering power is 120 W, the sputtering voltage is 500 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 100 °C.

[0055] The Al2O3 layer is formed on the second Al 2-z Gd z O3 layer as follows: The Al2O3 layer is deposited on the second Al 2-z Gd z O3 layer by magnetron sputtering. The sputtering target is an Al2O3 target, the power supply type is a radio frequency power supply, the sputtering power is 100 W, the sputtering voltage is 300 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 150 °C.

[0056] The first Al 2-x Gd x The thickness of the O3 layer is 30 nm, and the Al 2-y Sm y The thickness of the O3 layer is 30 nm, and the second Al 2-z Gd z The thickness of the O3 layer is 40 nm, and the thickness of the Al2O3 layer is 300 nm. The ratio of the change rate of the tensile strength of the sample in Example 2 is 7%.

[0057] Example 3

[0058] A composite insulating material for a cabinet-type current transformer is provided, including: a substrate; a Cu layer on the substrate; a CuAl layer on the Cu layer; a first Al 2-x Gd x O3 layer on the CuAl layer; a first Al 2-x Gd x O3 layer on the O3 layer; an Al 2-y Sm y O3 layer on the Al 2-y Sm y O3 layer; a second Al 2-z Gd z O3 layer on the O3 layer; and an Al2O3 layer on the second Al 2-z Gd z O3 layer.

[0059] The first Al 2-x Gd x The O3 layer is formed on the CuAl layer as follows: The first Al 2-x Gd x O3 layer is deposited on the CuAl layer by magnetron sputtering. The sputtering target is Al 2-xGd x GdO3 target, where x = 0.07, the power supply type is a radio frequency power supply, the sputtering power is 75 W, the sputtering voltage is 250 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 90 °C.

[0060] Al 2-y Sm y The AlSmO3 layer is formed on the first AlGdO3 layer by the following method: depositing the AlSmO3 layer on the first AlGdO3 layer by magnetron sputtering, where the sputtering target is the AlSmO3 target, where y = 0.03, the power supply type is a radio frequency power supply, the sputtering power is 100 W, the sputtering voltage is 250 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 90 °C. 2-x Gd x The AlGdO3 layer is formed on the first AlGdO3 layer by the following method: depositing the AlGdO3 layer on the first AlGdO3 layer by magnetron sputtering. 2-x Gd x The AlGdO3 layer is formed on the first AlGdO3 layer by the following method: depositing the AlGdO3 layer on the first AlGdO3 layer by magnetron sputtering. 2-y Sm y The AlSmO3 layer is formed on the first AlGdO3 layer by the following method: depositing the AlSmO3 layer on the first AlGdO3 layer by magnetron sputtering, where the sputtering target is the AlSmO3 target, where y = 0.03, the power supply type is a radio frequency power supply, the sputtering power is 100 W, the sputtering voltage is 250 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 90 °C. 2-y Sm y SmO3 target, where y = 0.03, the power supply type is a radio frequency power supply, the sputtering power is 100 W, the sputtering voltage is 250 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 90 °C.

[0061] The second AlGdO3 layer is formed on the AlSmO3 layer by the following method: depositing the second AlGdO3 layer on the AlSmO3 layer by magnetron sputtering, where the sputtering target is the AlGdO3 target, where z = 0.14, the power supply type is a radio frequency power supply, the sputtering power is 100 W, the sputtering voltage is 400 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 90 °C. 2-z Gd z The second AlGdO3 layer is formed on the AlSmO3 layer by the following method: depositing the second AlGdO3 layer on the AlSmO3 layer by magnetron sputtering. 2-y Sm y The second AlGdO3 layer is formed on the AlSmO3 layer by the following method: depositing the second AlGdO3 layer on the AlSmO3 layer by magnetron sputtering. 2-y Sm y The second AlGdO3 layer is formed on the AlSmO3 layer by the following method: depositing the second AlGdO3 layer on the AlSmO3 layer by magnetron sputtering. 2-z Gd z The second AlGdO3 layer is formed on the AlSmO3 layer by the following method: depositing the second AlGdO3 layer on the AlSmO3 layer by magnetron sputtering, where the sputtering target is the AlGdO3 target, where z = 0.14, the power supply type is a radio frequency power supply, the sputtering power is 100 W, the sputtering voltage is 400 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 90 °C. 2-z Gd z GdO3 target, where z = 0.14, the power supply type is a radio frequency power supply, the sputtering power is 100 W, the sputtering voltage is 400 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 90 °C.

[0062] The Al2O3 layer is formed on the second AlGdO3 layer by the following method: depositing the Al2O3 layer on the second AlGdO3 layer by magnetron sputtering, where the sputtering target is the Al2O3 target, the power supply type is a radio frequency power supply, the sputtering power is 70 W, the sputtering voltage is 250 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 140 °C. 2-z Gd z The Al2O3 layer is formed on the second AlGdO3 layer by the following method: depositing the Al2O3 layer on the second AlGdO3 layer by magnetron sputtering. 2-z Gd z The Al2O3 layer is formed on the second AlGdO3 layer by the following method: depositing the Al2O3 layer on the second AlGdO3 layer by magnetron sputtering, where the sputtering target is the Al2O3 target, the power supply type is a radio frequency power supply, the sputtering power is 70 W, the sputtering voltage is 250 V, the argon gas flow rate is 30 sccm, and the sputtering temperature is 140 °C.

[0063] The thickness of the first AlGdO3 layer is 25 nm, the thickness of the AlSmO3 layer is 25 nm, the thickness of the second AlGdO3 layer is 25 nm. 2-x Gd x The thickness of the first AlGdO3 layer is 25 nm, 2-y Sm y The thickness of the AlSmO3 layer is 25 nm, 2-zGd z The thickness of the Gd2O3 layer is 35 nm, and the thickness of the Al2O3 layer is 250 nm. The ratio of the change rate of the tensile strength of the sample of Example 1 is 6%.

[0064] Comparative Example 1

[0065] The composite insulating material does not include the Cu layer on the substrate, and the CuAl layer is directly formed on the substrate. Other process parameters refer to Example 1. Obvious cracks can be observed on the obtained composite insulating material.

[0066] Comparative Example 2

[0067] The composite insulating material does not include the CuAl layer, and other process parameters refer to Example 1. Obvious cracks can be observed on the obtained composite insulating material.

[0068] Comparative Example 3

[0069] The composite insulating material includes: a substrate, a Cu layer, a CuAl layer, Al 2-y Sm y 2O3 layer, a second Al 2-z Gd z 2O3 layer and an Al2O3 layer, and other process parameters refer to Example 1. The ratio of the change rate of the tensile strength of the sample of Comparative Example 3 is 13%. The reason for the change in the ratio of the change rate of the tensile strength is that crystallization occurs in the Al2O3 layer. To verify this conclusion, the present invention conducts a TEM test on the sample of Comparative Example 3, and the results are as Figure 4 shown. It can be clearly seen from the TEM photo the crystallized grains (i.e., black dots. If it is an amorphous Al2O3 film, there will be no contrast change in the TEM photo and it should be uniformly gray). The grain size in the figure is about 10 nm. The reason for the formation of crystallization is that due to the lack of the first Al 2-x Gd x 2O3 layer, this causes the lattice structure and the overlap of electron clouds of the second Al 2- z Gd z 2O3 layer to change. At this time, when the amorphous Al2O3 film contacts the second Al 2-z Gd z 2O3 layer, the overlap of their electron clouds may not be in the lowest energy state, so crystallization may occur in the Al2O3 film.

[0070] Comparative Example 4

[0071] The composite insulating material includes: a substrate, a Cu layer, a CuAl layer, a first Al 2-x Gd x 2O3 layer, a second Al 2-z Gd zThe O3 layer and the Al2O3 layer, and other process parameters refer to Example 1. The ratio of the change rate of the tensile strength of the sample of Comparative Example 4 is 15%.

[0072] Comparative Example 5

[0073] The first Al is deposited on the CuAl layer by magnetron sputtering 2-x Gd x O3 layer, wherein the sputtering target is Al 2-x Gd x O3 target, where x = 0.2, and other process parameters refer to Example 1. The ratio of the change rate of the tensile strength of the sample of Comparative Example 6 is 10%.

[0074] Comparative Example 6

[0075] The second Al is deposited on the Al 2-y Sm y O3 layer by magnetron sputtering 2-z Gd z O3 layer, wherein the sputtering target is Al 2- z Gd z O3 target, where z = 0.08, and other process parameters refer to Example 1. The ratio of the change rate of the tensile strength of the sample of Comparative Example 7 is 14%.

[0076] Comparative Example 7

[0077] The first Al is deposited on the CuAl layer by magnetron sputtering 2-x Gd x O3 layer, wherein the sputtering target is Al 2-x Gd x O3 target, the sputtering power is 200 W, the sputtering voltage is 400 V, and the Al is deposited on the first Al 2-x Gd x O3 layer by magnetron sputtering 2- y Sm y O3 layer, the sputtering power is 200 W, the sputtering voltage is 400 V, and other process parameters refer to Example 1. There are obvious cracks in the film layer of Comparative Example 8.

[0078] It should be understood that the above specific embodiments of the present invention are only used for exemplary illustration or explanation of the principle of the present invention, and do not constitute a limitation on the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A composite insulating material for a cabinet-type current transformer, wherein, The composite insulating material includes: a substrate; a Cu layer on the substrate; a CuAl layer on the Cu layer; First Al on the CuAl layer 2-x Gd x O3 layer; On the first Al 2-x Gd x O3 layer of Al 2-y Sm y O3 layer; On the second Al 2-y Sm y O3 layer; and 2-z Gd z O3 layer; and On the second Al 2-z Gd z Al2O3 layer on the O3 layer; where x = 0.05 - 0.1, y = 0.02 - 0.04, and z = 0.12 - 0.

16.

2. The composite insulating material according to claim 1, wherein The first Al 2-x Gd x The O3 layer is formed on the CuAl layer by the following method: Deposit the first Al on the CuAl layer by magnetron sputtering method 2-x Gd x O3 layer, wherein the sputtering target is Al 2- x Gd x O3 target, wherein the power supply type is radio frequency power supply, the sputtering power is 50 - 100 W, the sputtering voltage is 200 - 300 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

3. The composite insulating material according to claim 1, wherein The Al 2-y Sm y O3 layer is formed on the first Al 2-x Gd x O3 layer by the following method: Deposit the Al 2-x Gd x O3 layer on the first Al 2-y Sm y O3 layer, wherein the sputtering target is an Al 2-y Sm y O3 target, wherein the power supply type is a radio frequency power supply, the sputtering power is 60 - 120 W, the sputtering voltage is 200 - 300 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

4. The composite insulating material according to claim 1, wherein The second Al 2-z Gd z O3 layer is formed on the Al 2-y Sm y O3 layer by the following method: Deposit the second Al 2-y Sm y O3 layer on the Al 2-z Gd z O3 layer by magnetron sputtering method. Among them, the sputtering target is Al 2-z Gd z O3 target. Among them, the power supply type is radio frequency power supply, the sputtering power is 60 - 120 W, the sputtering voltage is 350 - 500 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

5. The composite insulating material according to claim 1, wherein The Al2O3 layer is formed on the second Al 2-z Gd z O3 layer by the following method: The Al2O3 layer is deposited on the second Al 2-z Gd z O3 layer by magnetron sputtering. The sputtering target is an Al2O3 target. The power supply type is a radio frequency power supply. The sputtering power is 50 - 100 W, the sputtering voltage is 200 - 300 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 130 - 150 °C.

6. The composite insulating material according to claim 1, wherein The first Al 2-x Gd x The thickness of the GdO3 layer is 20 - 30 nm, and the Al 2-y Sm y The thickness of the SmO3 layer is 20 - 30 nm, and the second Al 2-z Gd z The thickness of the GdO3 layer is 30 - 40 nm, and the thickness of the Al2O3 layer is 200 - 300 nm.

7. A method for preparing a composite insulating material for a cabinet-type current transformer, comprising: forming a Cu layer on a substrate; forming a CuAl layer on the Cu layer; Form a first Al layer on the CuAl layer 2-x Gd x O3 layer; On the first Al 2-x Gd x form an Al 2-y Sm y O3 layer; On the Al 2-y Sm y O3 layer, a second Al 2-z Gd z O3 layer is formed; and On the second Al 2-z Gd z An Al2O3 layer is formed on the O3 layer, where x = 0.05 - 0.1, y = 0.02 - 0.04, and z = 0.12 - 0.

16.

8. The method according to claim 7, wherein, Form a first Al layer on the CuAl layer 2-x Gd x The O3 layer comprises: Deposit the first Al on the CuAl layer by magnetron sputtering method 2-x Gd x O3 layer, wherein the sputtering target is Al 2- x Gd x O3 target, wherein the power supply type is radio frequency power supply, the sputtering power is 50 - 100W, the sputtering voltage is 200 - 300V, the argon gas flow rate is 20 - 30sccm, and the sputtering temperature is 80 - 100°C.

9. The method according to claim 7, wherein On the first Al 2-x Gd x An Al layer is formed on the O3 layer 2-y Sm y The O3 layer includes: Deposit the Al 2-x Gd x O3 layer on the first Al 2-y Sm y O3 layer, where the sputtering target is an Al 2-y Sm y O3 target, where the power supply type is a radio frequency power supply, the sputtering power is 60 - 120 W, the sputtering voltage is 200 - 300 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

10. The method according to claim 7, wherein, On the Al 2-y Sm y O3 layer, a second Al 2-z Gd z O3 layer is formed, including: Deposit the second Al 2-y Sm y O3 layer on the said Al 2-z Gd z O3 layer, wherein the sputtering target is an Al 2-z Gd z O3 target, wherein the power supply type is a radio frequency power supply, the sputtering power is 60 - 120 W, the sputtering voltage is 350 - 500 V, the argon gas flow rate is 20 - 30 sccm, and the sputtering temperature is 80 - 100 °C.

Images