Getter material capable of efficiently absorbing nitrogen, hydrogen and alkane gases and preparation method of getter material

Abstract

The invention relates to the field of getter materials, and discloses a getter material capable of efficiently absorbing nitrogen, hydrogen and alkane gases, a spherical powder getter material can absorb methane gas, and the getter material is composed of [(SiO2) x. (Al2O3) y. (CaO) z. (Fe2O3) m] a. (TiZrVNd) b, wherein a + b = 100%, x + y + z + m = 100%, and x is more than or equal to 30wt% and less than or equal to 50wt%; 20 wt% < = y < = 35 wt%; 10 wt% < = z < = 20 wt%; 10 wt% < = m < = 30 wt%; 70 wt% < = a < = 97 wt%. The getter material disclosed by the invention can absorb methane gas of various chip-containing devices of the MEMS, so that the precision, the service life and the power consumption of the sensor are improved.

Description

Technical Field

[0001] The present invention relates to the field of getter materials, and particularly to a getter material and system that have high-efficiency absorption of nitrogen, hydrogen, and alkane gases. Background Art

[0002] Currently, the spherical powdered metal oxide (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m getter can effectively remove N2 and H2 impurity gases in devices, but it is difficult to absorb the impurity CH4 gas in the gas, and the current (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m getter cannot solve this problem. Summary of the Invention

[0003] The main object of the present invention is to solve the technical problem that it is difficult for the getter in the prior art to absorb the impurity CH4 gas. A getter material that has high-efficiency absorption of nitrogen, hydrogen, and alkane gases, the getter material is spherical powder, and the composition of the getter material is: [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m]a·(TiZrVNd)b; wherein, a + b = 100%, x + y + z + m = 100%, 30wt% ≤ x ≤ 50wt%; 20wt% ≤ y ≤ 35wt%; 10wt% ≤ z ≤ 20wt%; 10wt% ≤ m ≤ 30wt%; 70wt% ≤ a ≤ 97wt%.

[0004] As a preferred technical solution, 80wt% ≤ a ≤ 90wt%, 40wt% ≤ x ≤ 45wt%; 22wt% ≤ y ≤ 25wt%; 12wt% ≤ z ≤ 15wt%; 18wt% ≤ m ≤ 23wt%. The particle size of the (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder is 0.3 - 15 mm. The particle size of the TiZrVNd powder is 5 - 30 μm. The specific surface area of the getter material is 800 - 1000 m 2 / g.

[0005] The present invention also relates to a preparation method of a getter material that has high-efficiency absorption of nitrogen, hydrogen, and alkane gases, and the method includes the following steps: Preparation of (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m SiO2, Al2O3, CaO, and Fe2O3 powders with different contents and a powder particle size of 30-200 μm are placed in a ball mill according to a certain proportion and ball milled. 5%-15% alcohol is added during the ball milling. Zirconia balls are used for the ball milling. The ball diameter is 0.5-2 mm. The ball-to-material ratio is 1-3. The ball milling time is 5-10 hours. (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder with a powder particle size of 3-30 nm is obtained. Preparation of TiZrVNd metal compound getter material, comprising: ① Ti, Zr, V, and Nd metals with a purity of 99.9% are prepared according to the formula of Ti, Zr, V, and Nd in the mass ratio; ②Put the prepared raw materials into the copper crucible of the melting furnace in the order of melting point from low to high, and then evacuate the melting furnace to (1-5)×10 -3 Pa, then 99.9999% high-purity argon gas was introduced to clean the furnace, and then the vacuum was evacuated to (1-5)×10 -3 Pa; ③The alloy was then melted in an argon atmosphere of 0.05MPa using a CZL-300 vacuum magnetron tungsten arc furnace; Turn on the arc melting power supply, first strike the arc on the tungsten electrode, then stabilize the arc and melt on the titanium ingot. During the melting process, the melting current is about 80~220A, so that the TiZrVNd alloy is completely melted and cast into an ingot. The whole melting process requires 4 melting passes. After each melting, the TiZrVNd alloy ingot is fully cooled, and then it is turned over by a robotic arm and melted again 4 times until it is uniform. The smelted alloy is crushed and ball-milled in a protective Ar or N2 atmosphere. The pressure of the protective atmosphere is 0.04-0.2 MPa. The ball-milling time is 2-10 hours. The powder is ball-milled to a powder of 3-30 microns to obtain TiZrVNd powder. (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder and TiZrVNd powder are physically mixed to obtain the gas-absorbing material [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m]a·(TiZrVNd)b.

[0006] The present invention has the following beneficial effects: Based on the existing spherical metal oxide SiO2, Al2O3, CaO, Fe2O3 getter materials, this application forms a composite spherical getter by adding spherical intermetallic compound Ti-Zr-V-Nd getter materials. This enables the spherical getter material to not only greatly enhance the absorption capacity for N2 and H2, but also enables the getter material to absorb CH4 while absorbing N2 and H2. This improves the problem of poor absorption capacity of existing metal oxides for alkane gases, and at the same time enhances the absorption capacity of metal oxides SiO2, Al2O3, CaO, Fe2O3 for N2, H2, and CH4. Description of the Drawings

[0007] Figure 1 It is a schematic diagram of the gas absorption principle of the getter material with high-efficiency absorption for nitrogen, hydrogen, and alkane gases provided by an embodiment of the present invention. Detailed Embodiments

[0008] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments described here can be implemented in an order different from that illustrated or described here. In addition, the term "comprising" or "having" and any variation thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0009] Existing spherical metal oxide getter materials are prepared by mixing spherical SiO2, Al2O3, CaO, and Fe2O3 in a certain proportion and further refining them to a particle size of 3-5 mm, forming spherical [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m], which is named A. A certain proportion b% of spherical intermetallic compound TiZrVNd is added to the A formulation, named B, to form a spherical AaBb powder getter. This getter can not only effectively absorb N2 and H2, but also absorb CH4 gas. When applied to gas containing CH4 impurities or a vacuum environment, it can effectively remove CH4 gas. Especially for various MEMS devices containing chips, since the chips are bonded with organic glue, a large amount of colloid will be released during service, and the colloid contains a large amount of methane gas. If CH4 gas is not absorbed in time, it will affect the accuracy, lifespan, and power consumption of the sensor, such as MEMS infrared sensors, MEMS gyroscopes, MEMS accelerometers, MEMS gun sights, MEMS radio frequency components, and MEMS inertial navigation instruments, to remove the methane gas introduced during chip gluing in semiconductor package devices, reduce the power consumption of the getter, and ensure the vacuum environment of semiconductor package devices.

[0010] Based on the current spherical powder metal oxide getter (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m (where a + b = 100%, x + y + z + m = 100%, 30wt% ≤ x ≤ 50wt%; 20wt% ≤ y ≤ 35wt%; 10wt% ≤ z ≤ 20wt%; 10wt% ≤ m ≤ 30wt%; 70wt% ≤ a ≤ 97wt%), the present invention forms a spherical AaBb powder composite getter, [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m]a·(TiZrVNd)b (where a + b = 100%, x + y + z + m = 100%, 30wt% ≤ x ≤ 50wt%; 20wt% ≤ y ≤ 35wt%; 10wt% ≤ z ≤ 20wt%; 10wt% ≤ m ≤ 30wt%; 70wt% ≤ a ≤ 97wt%) by adding spherical metal compound Ti-Zr-V-Nd powder. The composite getter AaBb not only has the function of absorbing CO and H2O, but also has the function of absorbing CH4.

[0011] The mechanism is as follows: In the spherical oxide (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m, through the 3d electron orbitals of Ti, Zr, and V in the metal compound and the 4f electron orbital of the rare earth element Nd, it can interact with impurity gases between N-N, H-H, and C-H bonds, making it easy for N2 gas molecules, H2 gas molecules, and CH4 gas molecules to dissociate and become C, H, and C atoms. Because for gases, the atomic radius is much smaller than the molecular radius, the gas atoms rapidly diffuse into the composite getter [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m]a·(TiZrVNd)b, achieving the effect of increasing the gas absorption rate.

[0012] At the same time, when no intermetallic compound is added, the adsorption force between the spherical metal oxide and gas molecules is only the van der Waals force. Moreover, the spherical metal oxide cannot dissociate the hydrogen molecules in H2 into H atoms, the nitrogen molecules in N2 into N atoms, and the carbon-hydrogen molecules in CH4 into C atoms and H atoms. However, after adding the metal compound Ti-Zr-V-Nd to component A, when the impurity gases H2, N2, and CH4 encounter the metal compound Ti-Zr-V-Nd, they can more effectively dissociate the H2 molecules into H atoms, the nitrogen molecules in N2 into N atoms, and the carbon-hydrogen molecules in CH4 into C atoms and H atoms. Therefore, when the spherical metal oxide (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m changes into the spherical AaBb composite getter, the absorption of gas not only has the van der Waals force between the gas molecules and the composite getter, but also has the adsorption of chemical bonds between the atoms and the composite getter, greatly increasing the absorption capacity of the composite getter and also endowing the composite getter with the ability to absorb methane.

[0013] For easy understanding, the specific process of the embodiment of the present invention is described below. Please refer to Figure 1 , the composition of the getter material of the first embodiment of the getter material with high-efficiency absorption of nitrogen, hydrogen, and alkane gases in the embodiment of the present invention is: [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m]a·(TiZrVNd)b; where a + b = 100%, x + y + z + m = 100%, 30wt% ≤ x ≤ 50wt%; 20wt% ≤ y ≤ 35wt%; 10wt% ≤ z ≤ 20wt%; 10wt% ≤ m ≤ 30wt%; 70wt% ≤ a ≤ 97wt%.

[0014] As a preferred embodiment, 80 wt% ≤ a ≤ 90 wt%, 40 wt% ≤ x ≤ 45 wt%; 22 wt% ≤ y ≤ 25 wt%; 12 wt% ≤ z ≤ 15 wt%; 18 wt% ≤ m ≤ 23 wt%.

[0015] As a preferred embodiment, the particle size of the (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder is 0.3 - 15 mm.

[0016] As a preferred embodiment, the particle size of the TiZrVNd powder is 5 - 30 μm.

[0017] As a preferred embodiment, the specific surface area of the getter material is 800 - 1000 m 2 / g.

[0018] The preparation method includes the following steps: Preparation of (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m Put SiO2, Al2O3, CaO, and Fe2O3 powders with different contents and a powder particle size composition of 30 - 200 μm into a ball mill of a certain model in proportion, and add 5% - 15% alcohol during ball milling. Zirconia balls are used for ball milling, the diameter of the balls is 0.5 - 2 mm, the ball-to-material ratio is 1 - 3, and the ball milling time is 5 - 10 hours; to obtain (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder with a powder particle size of 3 - 30 nm; Preparation of the TiZrVNd metal compound getter material, including: ① Weigh Ti, Zr, V, and Nd metals with a purity of 99.9% according to the formula of the mass ratio of Ti, Zr, V, and Nd for batching; ② Put the prepared raw materials into the copper crucible of the melting furnace in the order of increasing melting point, then evacuate the melting furnace to (1 - 5) × 10 -3 Pa, then introduce 99.9999% high-purity argon for furnace washing, and then evacuate to (1 - 5) × 10 -3 Pa; ③ Then melt the alloy under an argon atmosphere of 0.05 MPa. A CZL-300 type vacuum magnetron tungsten electrode arc furnace is used for melting; Turn on the power of the arc melting, first strike an arc on the tungsten electrode, then stabilize the arc and melt on the titanium ingot. During melting, the melting current is about 80 - 220 A, so that the TiZrVNd alloy is completely melted and cast into an ingot. The entire melting process needs to be melted 4 times. After each melting, wait for the TiZrVNd alloy ingot to cool sufficiently, and then use the robotic arm to turn it over and melt it 4 more times until it is uniform; Under a protective Ar or N2 atmosphere, the smelted alloy is crushed and ball-milled to form a TiZrVNd alloy ingot. The pressure of the protective atmosphere is 0.04 - 0.2 MPa, and the ball-milling time is 2 - 10 h. The powder is ball-milled to a powder with a particle size of 3 - 30 microns to obtain TiZrVNd powder; The (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder and the TiZrVNd powder are physically mixed to obtain a getter material [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m]a·(TiZrVNd)b.

[0019] Carry out corresponding experiments according to the foregoing scheme and the parameters in Table 1.

[0020] Among them, 45% SiO2·22% Al2O3·15% CaO·18% FeO: F1; 40% SiO2·25% Al2O3·12% CaO·23% FeO: F2; 40% SiO2·22% Al2O3·15% CaO·23% FeO: F3.

[0021] Table 1 From the above experimental data, it can be seen that in Examples 6 and 7, the getter performance of the present invention is particularly prominent. In the oxide (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m, through the unpaired electrons of the 3d electron orbitals of Ti, Zr, and V in the metal compound and the 4f electron orbitals of the rare earth element Nd, the H2 molecules are more effectively dissociated into H atoms, the nitrogen molecules in N2 are dissociated into N atoms, and the CH4 hydrocarbon molecules are dissociated into C atoms and H atoms. Because for gases, the atomic radius is much smaller than the molecular radius, the gas atoms rapidly diffuse into the composite getter (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m·(TiZrVNd)a, achieving the effect of increasing the gas absorption rate.

[0022] From Figure 1It can be seen that due to the physical action of van der Waals forces on the surface of spherical oxides (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m, H2 and N2 gas molecules are adsorbed on its surface. However, the oxide powder cannot dissociate H2 and N2 gas molecules into atoms. Spherical (TiZrVNd) intermetallic compounds can absorb CH4 and dissociate it into C and H atoms. At the same time, they can also convert H2 and N2 gas molecules into H atoms and N atoms. When (TiZrVNd) intermetallic compounds are added to (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m to form [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m]a·(TiZrVNd)b, the composite getter will dissociate N2, H2, and CH4 with dissociation energies of 492 kJ / mol, 436 kJ / mol, and 1661 kJ / mol respectively into N, H, and C / H atoms. The gas atoms diffuse in the spherical composite getter powder with a large specific surface area, achieving a high ability to absorb N2, H2, and CH4.

[0023] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A getter material with high efficiency in absorbing nitrogen, hydrogen and alkane gases, characterized in that: The getter material is a spherical powder, and the getter material is composed of: [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m]a·(TiZrVNd)b; Among them, a+b=100%, x+y+z+m=100%, 30wt%≤x≤50wt%; 20wt%≤y≤35wt%; 10wt%≤z≤20wt%; 10wt%≤m≤30wt%; 70wt%≤a≤97wt%, 3wt%≤b≤30wt%.

2. The getter material with high absorption efficiency for nitrogen, hydrogen and alkane gases according to claim 1, characterized in that, The 80wt%≤a≤90wt%, 10wt%≤b≤20wt%, the 40wt%≤x≤45wt%; 22wt%≤y≤25wt%; 12wt%≤z≤15wt%; 18wt%≤m≤23wt%.

3. The getter material with high absorption efficiency for nitrogen, hydrogen and alkane gases according to claim 1, characterized in that, The particle size of the (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder is 0.3-15mm.

4. The getter material having high efficiency in absorbing nitrogen, hydrogen and alkane gases according to claim 1, characterized in that: The particle size of the TiZrVNd powder is 5-30 μm.

5. The getter material with high absorption efficiency for nitrogen, hydrogen and alkane gases according to claim 1, characterized in that, The specific surface area of the suction material is 800-1000m 2 / g.

6. A method for preparing a getter material with high efficiency in absorbing nitrogen, hydrogen and alkane gases, characterized in that, The method comprises the following steps: Preparation of (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m SiO2, Al2O3, CaO, and Fe2O3 powders with different contents and a powder particle size of 30-200 μm are placed in a ball mill according to a certain proportion and ball milled. 5%-15% alcohol is added during the ball milling. Zirconia balls are used for the ball milling. The ball diameter is 0.5-2 mm. The ball-to-material ratio is 1-3. The ball milling time is 5-10 hours. (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder with a powder particle size of 3-30 nm is obtained. Preparation of TiZrVNd metal compound getter material, comprising: ① Ti, Zr, V, and Nd metals with a purity of 99.9% are prepared according to the formula of Ti, Zr, V, and Nd in the mass ratio; ②Put the prepared raw materials into the copper crucible of the melting furnace in the order of increasing melting point, and then evacuate the melting furnace to (1-5)×10 -3 Pa, then introduce 99.9999% high-purity argon gas for furnace washing, and then evacuate to (1-5)×10 -3 Pa; ③The alloy was then melted in an argon atmosphere of 0.05MPa using a CZL-300 vacuum magnetron tungsten arc furnace; Turn on the arc melting power supply, first strike the arc on the tungsten electrode, then stabilize the arc and melt on the titanium ingot. During the melting process, the melting current is about 80~220A, so that the TiZrVNd alloy is completely melted and cast into an ingot. The whole melting process requires 4 melting passes. After each melting, the TiZrVNd alloy ingot is fully cooled, and then it is turned over by a robotic arm and melted again 4 times until it is uniform. The smelted alloy is crushed and ball-milled in a protective Ar or N2 atmosphere. The pressure of the protective atmosphere is 0.04-0.2 MPa. The ball-milling time is 2-10 hours. The powder is ball-milled to a powder of 3-30 microns to obtain TiZrVNd powder. (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder and TiZrVNd powder are physically mixed to obtain the gas-absorbing material [(SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m]a·(TiZrVNd)b.

7. The preparation method of a getter material with high absorption efficiency for nitrogen, hydrogen and alkane gases according to claim 1, characterized in that, 80 wt% ≤ a ≤ 90 wt%, 40 wt% ≤ x ≤ 45 wt%; 22 wt% ≤ y ≤ 25 wt%; 12 wt% ≤ z ≤ 15 wt%; 18 wt% ≤ m ≤ 23 wt%.

8. The preparation method of a getter material with high absorption efficiency for nitrogen, hydrogen and alkane gases according to claim 1, characterized in that, The particle size of the (SiO2)x·(Al2O3)y·(CaO)z·(Fe2O3)m powder is 0.3 - 15 mm.

9. The preparation method of a getter material with high absorption efficiency for nitrogen, hydrogen and alkane gases according to claim 1, characterized in that, The particle size of the TiZrVNd powder is 5 - 30 μm.

10. The preparation method of a getter material with high efficiency in absorbing nitrogen, hydrogen and alkane gases according to claim 1, characterized in that, The specific surface area of the suction material is 800 - 1000 m 2 / g.

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