A method for preparing an ultralow-temperature-drift high-power alloy resistor
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN SHUNHAI TECH CO LTD
- Filing Date
- 2026-04-28
- Publication Date
- 2026-08-07
AI Technical Summary
而为实现高功率密度意味着在更小的封装尺寸内耗散更高的功率，因高功率下合金电阻体自身及与基板间的热膨胀失配会引入显著的热应力，破坏电阻合金的微观结构，导致TCR特性劣化甚至阻值漂移
1、本申请通过在氧化铝陶瓷基板和合金箔间设置由钛、二维氮化硼纳米片和镍组成的复合金属化层，在应用过程中不仅可构筑高效的平面方向导热通路，还能够通过应力缓冲保护电阻合金箔的微观结构，如此在电阻合金与陶瓷基板之间构建了一个兼具高导热和高应力缓冲能力的智能复合界面层，这一设计巧妙地化解了高功率密度带来的热应力与超低TCR所需的材料稳定性之间的矛盾，能够协同实现超低温漂与高功率密度。
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Abstract
Description
Technical Field
[0001] This application relates to the field of alloy resistor technology, and more specifically, it relates to a method for preparing a high-power alloy resistor with ultra-low temperature drift. Background Technology
[0002] Alloy resistors are widely used in precision instruments, automotive electronics, industrial control, and communication equipment due to their excellent temperature stability, low noise, and high reliability. As electronic technology advances towards higher precision and reliability, higher demands are being placed on the core performance indicators of resistors—temperature coefficient (TCR, i.e., temperature drift) and high power density.
[0003] The temperature coefficient (TCR) of alloy resistors is mainly determined by the composition, crystal structure, and microstructure of the resistor alloy material. To achieve ultra-low TCR, it is often necessary to select a precision alloy with a specific ratio and to eliminate internal stress and stabilize the microstructure through complex melting and heat treatment processes. However, achieving high power density means dissipating higher power within a smaller package size. Under high power, the thermal expansion mismatch between the alloy resistor body itself and the substrate will introduce significant thermal stress, which will damage the microstructure of the resistor alloy, leading to TCR degradation and even resistance drift.
[0004] With the trend towards miniaturization, high power density leads to a sharp increase in heat dissipation per unit volume. If heat cannot be dissipated in time, the local temperature rise of the alloy resistive element will far exceed the ambient temperature rise. This will not only directly affect the deterioration of the TCR measurement value, but also accelerate material aging and oxidation, causing long-term resistance drift, and even leading to fatal failures such as open circuits and short circuits. Under the influence of high power density, metal ions in the resistive alloy may migrate under the combined action of electric and thermal fields, changing the local microstructure and thus affecting the resistance stability and TCR characteristics. Ultra-low TCR design requires materials with extremely high stability, making it difficult to impose higher requirements on high power density.
[0005] Therefore, given the current limitations of alloy resistors in achieving both ultra-low temperature drift and high power density, a solution is urgently needed to address these technical issues. Summary of the Invention
[0006] In order to manufacture alloy resistors that combine excellent low temperature drift and high power density, this application provides a method for preparing a high-power alloy resistor with low temperature drift.
[0007] This application provides a method for preparing an ultra-low temperature drift high-power alloy resistor, which adopts the following technical solution: A method for preparing a high-power alloy resistor with ultra-low temperature drift includes the following steps: (1) A master alloy containing nickel, chromium, aluminum, silicon, manganese, copper and iron is prepared by vacuum induction melting and rolled into alloy foil; (2) An alumina ceramic substrate is selected, and its surface is treated to form a micron-level roughened surface and trenches with a predetermined pattern. Then, a titanium layer is deposited on the roughened surface and in the trenches, and a two-dimensional boron nitride nanosheet aerosol is introduced. At the same time, Ar is applied. + Ion bombardment is performed to embed two-dimensional boron nitride nanosheets into a nickel layer, followed by nickel layer deposition to finally form a composite metallization layer, resulting in a pretreated alumina ceramic substrate. (3) The alloy foil obtained in step (1) is temporarily fixed on the pretreated alumina ceramic substrate obtained in step (2), and after being cut to form a preset resistance pattern, it is sintered to obtain a semi-finished alloy resistor. (4) After the alloy resistor semi-finished product obtained in step (3) is subjected to controlled oxidation and passivation treatment, the end face is electroplated with electrodes to obtain an ultra-low temperature drift high power alloy resistor.
[0008] By adopting the above technical solution, the master alloy containing nickel, chromium, aluminum, silicon, manganese, copper and iron can achieve precise control over resistivity, temperature coefficient and thermal stability through the combination of multiple elements. It can then be rolled into foil to prepare for the preparation of planar resistive bodies.
[0009] Next, after forming a micron-level roughened surface and predetermined patterned trenches on the surface of the alumina ceramic substrate, a titanium layer is first deposited, followed by the introduction of two-dimensional boron nitride nanosheets, and finally a nickel layer is deposited to form the final composite metallization layer. The aforementioned roughened surface and trenches greatly increase the contact area between the alloy resistor and the substrate, providing a strong mechanical interlocking structure for subsequent sintering and preventing delamination. The titanium layer has strong adhesion to the ceramic substrate, making it an excellent underlayer. The introduction of two-dimensional boron nitride nanosheets not only constructs efficient planar heat conduction pathways, rapidly diffusing the heat generated by the resistor body laterally to avoid the formation of local hot spots and effectively reduce the actual operating temperature of the resistor alloy foil, thus allowing it to withstand higher power in a smaller volume, but also absorbs and dissipates shear stress caused by CTE mismatch, protecting the microstructure of the resistor alloy foil through stress buffering, ensuring that its TCR characteristics remain stable under high-power thermal cycling. The nickel layer provides good solderability, conductivity, and a foundation for connection with the upper alloy foil. The combination of these three elements as a composite metallization layer achieves high thermal conductivity for rapid heat dissipation to support high power density, and high toughness / low stress to protect the resistor body to obtain stable TCR, thereby synergistically achieving ultra-low temperature drift and high power density.
[0010] Subsequently, the alloy foil is temporarily fixed to the pretreated substrate, cut into patterns, and then sintered to form a strong metallurgical bond between the alloy foil and the underlying composite metallization layer. Finally, the resistor undergoes controlled oxidation and passivation treatment, mainly forming an extremely thin, dense, and stable oxide layer on the surface of the alloy foil. This oxide layer pins grain boundaries, inhibiting further oxidation and element diffusion, and is a key surface treatment process for stabilizing resistance values and achieving ultra-low TCR and low long-term drift. The end-face electroplating is to form solderable and corrosion-resistant external electrodes, facilitating circuit assembly.
[0011] Preferably, in step (2), the volume fraction of the two-dimensional boron nitride nanosheets in the composite metallization layer is 2-3%, the thickness of the two-dimensional boron nitride nanosheets is 3-5 nm, and the lateral dimension is 50-200 nm.
[0012] By employing the above technical solution, a volume fraction of 2-3% for two-dimensional boron nitride nanosheets is sufficient to form a preliminary, interconnected two-dimensional thermally conductive network, exhibiting excellent stress-buffering effects. Simultaneously, the aforementioned specifications of two-dimensional boron nitride nanosheets not only ensure excellent two-dimensional properties and flexibility, effectively maintaining their intrinsic high thermal conductivity and stress-buffering function, but also optimize network formation and dispersion, thereby forming an effective permeation network for heat conduction and stress transfer. Thus, the aim is to utilize the maximum advantages of nanoscale two-dimensional materials with minimal introduction, ultimately ensuring the composite metallization layer achieves optimal performance.
[0013] Preferably, in step (2), the titanium layer deposition thickness is 50-60 nm and the nickel layer deposition thickness is 180-220 nm.
[0014] By employing the above technical solution, a titanium layer deposition thickness of 50-60 nm ensures continuity, density, and effective adhesion, providing a foundation for the subsequent embedding of two-dimensional boron nitride nanosheets. A nickel layer deposition thickness of 180-220 nm provides ample space, enabling the two-dimensional boron nitride nanosheets to form a true three-dimensional composite structure. During subsequent sintering, this allows for the formation of a sufficiently thick and strong diffusion bonding layer with the alloy foil, ensuring extremely low interfacial thermal resistance and extremely high bonding strength. Thus, the total thickness of the composite metallization layer achieves strong mechanical anchoring, efficient thermal and electrical conductivity, and stress buffering, while maintaining sufficient flexibility and not significantly affecting the overall size of the miniaturized resistor.
[0015] Preferably, in step (2), the two-dimensional boron nitride nanosheets are modified before use, including the following modification steps: S1. Two-dimensional boron nitride nanosheets, graphene oxide, and yttrium nitrate are dispersed together in a mixed solvent of deionized water and ethanol, and then ultrasonically formed into a uniform suspension. S2, 3-aminopropyltriethoxysilane and urea are added to the uniform suspension obtained in step S1. After adjusting the pH, the mixture is transferred to a reaction vessel for a one-pot heating reaction. After the reaction is completed, the mixture is allowed to cool naturally. The product is then collected by centrifugation and washed and annealed to obtain modified two-dimensional boron nitride nanosheets.
[0016] By adopting the above technical solution, in the preparation of modified two-dimensional boron nitride nanosheets, the surface of the two-dimensional boron nitride nanosheets is modified with 3-aminopropyltriethoxysilane, graphene oxide is reduced and interacts with the modified two-dimensional boron nitride nanosheets and yttrium, while yttrium ions are deposited / grown in the form of nitrogen / oxygen compounds at the interface between the two-dimensional boron nitride nanosheets and the reduced graphene oxide. When modified two-dimensional boron nitride nanosheets are applied to the preparation of ultra-low temperature drift high-power alloy resistors, firstly, the interfacial bonding energy between the nanosheets and the nickel layer is significantly improved during subsequent ion bombardment and nickel layer deposition, transforming it from passive filling to active reinforcement bonding, thus making it less prone to debonding under thermal stress. Secondly, the combination of yttrium ceramic phase and graphite carbon layer can act as a "bridge" to further reduce interfacial thermal resistance, resulting in a significant improvement in the effective thermal conductivity of the composite metallization layer compared to the use of unmodified two-dimensional boron nitride nanosheets. Moreover, the gradient interfacial layer formed by yttrium ceramic phase, graphite carbon layer, and two-dimensional boron nitride nanosheets has a better modulus transition, which can more effectively buffer and disperse stress. At the same time, the modified two-dimensional boron nitride nanosheets have excellent dispersibility and are not prone to agglomeration, which is more conducive to achieving uniform dispersion in subsequent "ion bombardment embedding". Thus, by modifying the two-dimensional boron nitride nanosheets before use, a multi-component, multi-scale gradient functionalized interface layer can be constructed on the surface of the two-dimensional boron nitride nanosheets. This not only significantly reduces the interfacial thermal resistance and removes the heat dissipation bottleneck, but also forms a more stable and efficient three-dimensional heat conduction network. As a result, the steady-state power that the resistor can withstand under the same size is greatly improved, that is, the power density is increased. At the same power, the operating temperature of the resistor body is lower, which creates conditions for maintaining low TCR. Ultimately, the overall quality of the ultra-low temperature drift high-power alloy resistor is further improved.
[0017] Preferably, the weight mixing ratio of the two-dimensional boron nitride nanosheet raw material, graphene oxide and yttrium nitrate is (9-12):(0.4-0.6):1.
[0018] By adopting the above technical solution and at the above ratio, the modified two-dimensional boron nitride nanosheets obtained in the end retain the intrinsic advantages of two-dimensional boron nitride nanosheets to the greatest extent, while forming a more stable and superior bonding morphology, which is conducive to constructing ultra-high performance composite metallization layers.
[0019] Preferably, in step S2, the temperature of the one-pot heating reaction is 180-220℃, and the reaction time is 16-24h.
[0020] By adopting the above technical solution, a reaction temperature of 180-220℃ can ensure that the reaction has sufficient driving force to overcome the energy barrier, thus guaranteeing the high efficiency and thoroughness of the functionalization reaction; a reaction time of 16-24h can achieve sufficient diffusion of reactants, complete reaction, and uniform growth of products; in this way, it is ensured that each two-dimensional boron nitride nanosheet can obtain a modified interface layer with consistent quality and structure, ultimately resulting in modified boron nitride nanosheets with strong interfacial bonding, high thermal conductivity bridges, and excellent dispersibility.
[0021] Preferably, in step (1), the alloy foil comprises the following components in parts by weight: 45-50 parts nickel; Chromium 20-25 parts; 4-6 parts aluminum; Silicon 1.5-2.5 parts; 2-3 parts manganese; 3-5 parts copper; Iron 10-15 parts.
[0022] By adopting the above technical solutions, nickel and chromium form the matrix framework of the alloy foil, aluminum and silicon are the basis for achieving ultra-low temperature coefficients, manganese can purify the alloy liquid, copper can improve processing performance, and iron can optimize costs without sacrificing core functions. Therefore, the combination of the above elements ultimately produces a resistance alloy foil with extremely low temperature coefficient, suitable resistivity, good processability, and reasonable cost.
[0023] Preferably, in step (1), the thickness of the alloy foil is 1.8-2.2 μm.
[0024] By adopting the above technical solution, a thickness of 1.8-2.2μm can ensure a high degree of uniformity in composition, texture, and thickness of the alloy foil across the entire area under existing rolling technology. This is a prerequisite for achieving low TCR. At the same time, the excellent heat dissipation capacity of the underlying composite metallization layer requires the upper resistor to have a reasonable "heat source thickness" to match. This thickness makes the resistor a highly efficient surface heat source, rather than a difficult-to-dissipate volume heat source, allowing the advanced heat dissipation design of the lower layer to play its maximum role. In this way, it is beneficial to ensure excellent performance in "ultra-low temperature drift" and "high power density".
[0025] Preferably, in step (3), sintering is carried out in a nitrogen atmosphere containing 5% H2, the sintering temperature is 700-750℃, and the sintering time is 10-15min.
[0026] By adopting the above technical solution, in a nitrogen atmosphere containing 5% H2 at a high temperature above 700℃, H2 can react with metal oxides, thereby achieving in-situ removal of oxides at the interface and exposing a pure and active metal surface. The sintering temperature is 700-750℃ and the sintering time is 10-15min, which enables the alloy foil and the underlying composite metallization layer to form a strong metallurgical bond through atomic interdiffusion, without causing the deterioration of the microstructure of the alloy foil or the excessive growth of harmful phases, ensuring that a high-quality and stable ultra-low temperature drift high-power alloy resistor is finally obtained.
[0027] Preferably, in step (4), in a mixture containing 5% O 2 Controllable oxidation and passivation treatment is performed in a nitrogen atmosphere at a temperature of 500-550℃ for 20-30 minutes.
[0028] By adopting the above technical solution, 5%O 2 The nitrogen atmosphere provides a precisely controllable low oxygen partial pressure environment, enabling selective oxidation and avoiding catastrophic over-oxidation. The processing temperature of 500-550℃ and the processing time of 20-30min ensure that the oxide film grows completely and densely, reaching a minimum critical thickness that can provide long-term effective protection. It also stabilizes the microstructure of the outermost layer of the resistance alloy, which can significantly suppress the long-term drift of the resistance value under high-temperature load and help maintain the stability of TCR.
[0029] In summary, this application has the following beneficial effects: 1. This application establishes a composite metallization layer composed of titanium, two-dimensional boron nitride nanosheets, and nickel between an alumina ceramic substrate and an alloy foil. During application, this layer not only constructs an efficient planar thermal conductivity path but also protects the microstructure of the resistance alloy foil through stress buffering. In this way, a smart composite interface layer with both high thermal conductivity and high stress buffering capability is constructed between the resistance alloy and the ceramic substrate. This design cleverly resolves the contradiction between the thermal stress caused by high power density and the material stability required for ultra-low TCR, and can synergistically achieve ultra-low temperature drift and high power density.
[0030] 2. This application modifies two-dimensional boron nitride nanosheets before use, constructing a multi-component, multi-scale gradient functionalized interface layer on the surface of the two-dimensional boron nitride nanosheets. Through the special combination between the yttrium ceramic phase, the graphite carbon layer and the two-dimensional boron nitride nanosheets, stress can be buffered and dispersed more effectively, and the effective thermal conductivity of the composite metallization layer is significantly improved compared with the use of unmodified two-dimensional boron nitride nanosheets. This further improves the balance and performance of the ultra-low temperature drift high-power alloy resistor in terms of both ultra-low temperature drift and high power density. Detailed Implementation
[0031] The present application will be further described in detail below with reference to preparation examples, embodiments and comparative examples.
[0032] Unless otherwise specified, all raw materials used in the preparation examples, embodiments and comparative examples of this application are commercially available.
[0033] The alumina ceramic substrate was purchased from Shanghai Xinmao Precision Ceramics Technology Co., Ltd. as a 76*25*1.0 (mm) ceramic sheet 96% alumina ceramic substrate.
[0034] Preparation examples of raw materials and / or intermediates Preparation Example 1 A modified two-dimensional boron nitride nanosheet was prepared by the following steps: S1. Two-dimensional boron nitride nanosheets, graphene oxide, and yttrium nitrate are dispersed together in a mixed solvent of deionized water and ethanol at a volume ratio of 4:1 at a concentration of 7.5 mg / mL, and then ultrasonically mixed to form a uniform suspension. S2, 3-aminopropyltriethoxysilane and urea are added to the uniform suspension obtained in step S1. After adjusting the pH to 9, the mixture is transferred to a reaction vessel for a one-pot heating reaction. After the reaction is completed, the mixture is allowed to cool naturally. The product is then collected by centrifugation, washed with water and ethanol, and annealed at 450°C for 1.5 h to obtain modified two-dimensional boron nitride nanosheets.
[0035] Note: In the above operations, in step S1, the weight mixing ratio of the two-dimensional boron nitride nanosheet raw material, graphene oxide, and yttrium nitrate is 10.5:0.5:1; the thickness of the two-dimensional boron nitride nanosheets is 4 nm, and the lateral dimension is 125 nm. In step S2, the one-pot heating reaction temperature is 200℃, and the reaction time is 20 h; the mass ratio of 3-aminopropyltriethoxysilane to the two-dimensional boron nitride nanosheet raw material is 1.5:1; and the molar ratio of urea to yttrium ions is 30:1.
[0036] Preparation Example 2 A modified two-dimensional boron nitride nanosheet differs from preparation example 1 in that, in step S1, the weight mixing ratio of the two-dimensional boron nitride nanosheet raw material, graphene oxide, and yttrium nitrate is 9:0.4:1.
[0037] Preparation Example 3 A modified two-dimensional boron nitride nanosheet differs from preparation example 1 in that, in step S1, the weight mixing ratio of the two-dimensional boron nitride nanosheet raw material, graphene oxide, and yttrium nitrate is 12:0.6:1.
[0038] Preparation Example 4 A modified two-dimensional boron nitride nanosheet differs from preparation example 1 in that, in step S2, the one-pot heating reaction temperature is 180°C and the reaction time is 24 h.
[0039] Preparation Example 5 A modified two-dimensional boron nitride nanosheet differs from preparation example 1 in that, in step S2, the one-pot heating reaction temperature is 220°C and the reaction time is 164 h.
[0040] Preparation Example 6 A modified two-dimensional boron nitride nanosheet, which differs from preparation example 1 in that the two-dimensional boron nitride nanosheet has a thickness of 3 nm and a lateral dimension of 50 nm.
[0041] Preparation Example 7 A modified two-dimensional boron nitride nanosheet differs from preparation example 1 in that the two-dimensional boron nitride nanosheet has a thickness of 5 nm and a lateral dimension of 200 nm.
[0042] Example Example 1
[0043] A method for preparing a high-power alloy resistor with ultra-low temperature drift includes the following steps: (1) A master alloy containing nickel, chromium, aluminum, silicon, manganese, copper and iron is prepared by vacuum induction melting and rolled into alloy foil; (2) An alumina ceramic substrate is selected, and its surface is treated to form a micron-level roughened surface with a roughness of 0.8 μm and trenches with a predetermined pattern of 15 μm depth. Then, a titanium layer is deposited on the roughened surface and in the trenches, and a two-dimensional boron nitride nanosheet aerosol (concentration 0.1 mg / m³) is introduced. 3 ), while applying Ar + Ion bombardment is performed to embed two-dimensional boron nitride nanosheets into a nickel layer, followed by nickel layer deposition to finally form a composite metallization layer, resulting in a pretreated alumina ceramic substrate. (3) The alloy foil obtained in step (1) is temporarily fixed on the pretreated alumina ceramic substrate obtained in step (2), and after being cut to form a preset resistance pattern, it is sintered to obtain a semi-finished alloy resistor. (4) After the alloy resistor semi-finished product obtained in step (3) is subjected to controlled oxidation and passivation treatment, the end face is electroplated with electrodes to obtain an ultra-low temperature drift high power alloy resistor.
[0044] Note: The composition and corresponding weight parts of the alloy foil in the above operations are shown in Table 1. The volume fraction of the two-dimensional boron nitride nanosheets in the composite metallization layer is 2.5%, the thickness of the two-dimensional boron nitride nanosheets is 4 nm, and the lateral dimension is 125 nm. The titanium layer deposition thickness is 55 nm, and the nickel layer deposition thickness is 200 nm. The thickness of the alloy foil is 2 μm. In step (3), sintering is carried out in a nitrogen atmosphere containing 5% H2, the sintering temperature is 725 °C, and the sintering time is 12.5 min. In step (4), in a nitrogen atmosphere containing 5% O2, sintering is carried out in a nitrogen atmosphere containing 5% O2. 2Controllable oxidation and passivation treatment was performed in a nitrogen atmosphere at a temperature of 525℃ for 25 minutes. Example 2-3
[0045] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the composition and corresponding weight parts of the alloy foil are shown in Table 1.
[0046] Table 1. Components and corresponding weight parts (parts / kg) of the alloy foils in Examples 1-3 Example 4
[0047] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the volume fraction of two-dimensional boron nitride nanosheets in the composite metallization layer is 2%, the thickness of the two-dimensional boron nitride nanosheets is 3 nm, and the lateral dimension is 50 nm. Example 5
[0048] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the volume fraction of two-dimensional boron nitride nanosheets in the composite metallization layer is 3%, the thickness of the two-dimensional boron nitride nanosheets is 5 nm, and the lateral dimension is 200 nm. Example 6
[0049] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the titanium layer deposition thickness is 50 nm and the nickel layer deposition thickness is 180 nm. Example 7
[0050] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the titanium layer deposition thickness is 60 nm and the nickel layer deposition thickness is 220 nm. Example 8
[0051] A method for preparing an ultra-low temperature drift high-power alloy resistor, which differs from Example 1 in that the thickness of the alloy foil is 1.8 μm. Example 9
[0052] A method for preparing an ultra-low temperature drift high-power alloy resistor, which differs from Example 1 in that the thickness of the alloy foil is 2.2 μm. Example 10
[0053] A method for preparing an ultra-low temperature drift high power alloy resistor differs from Example 1 in that, in step (3), sintering is carried out in a nitrogen atmosphere containing 5% H2, the sintering temperature is 700℃, and the sintering time is 15min. Example 11
[0054] A method for preparing an ultra-low temperature drift high power alloy resistor differs from Example 1 in that, in step (3), sintering is carried out in a nitrogen atmosphere containing 5% H2, the sintering temperature is 750℃, and the sintering time is 10min. Example 12
[0055] A method for preparing an ultra-low temperature drift high-power alloy resistor, which differs from Example 1 in that, in step (4), in a solution containing 5% O 2 Controllable oxidation and passivation treatment was performed in a nitrogen atmosphere at a temperature of 500℃ for 30 minutes. Example 13
[0056] A method for preparing an ultra-low temperature drift high-power alloy resistor, which differs from Example 1 in that, in step (4), in a solution containing 5% O 2 Controllable oxidation and passivation treatment was performed in a nitrogen atmosphere at a temperature of 550℃ for 20 minutes. Example 14
[0057] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the two-dimensional boron nitride nanosheets are modified before use, and the modified two-dimensional boron nitride nanosheets obtained are obtained from Preparation Example 1. Example 15
[0058] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the two-dimensional boron nitride nanosheets are modified before use, and the modified two-dimensional boron nitride nanosheets are obtained from Preparation Example 2. Example 16
[0059] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the two-dimensional boron nitride nanosheets are modified before use, and the modified two-dimensional boron nitride nanosheets are obtained from Preparation Example 3. Example 17
[0060] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the two-dimensional boron nitride nanosheets are modified before use, and the modified two-dimensional boron nitride nanosheets are obtained from Preparation Example 4. Example 18
[0061] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the two-dimensional boron nitride nanosheets are modified before use, and the modified two-dimensional boron nitride nanosheets obtained are obtained from Preparation Example 5. Example 19
[0062] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the two-dimensional boron nitride nanosheets are modified before use, and the modified two-dimensional boron nitride nanosheets are obtained from Preparation Example 6. Example 20
[0063] A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that the two-dimensional boron nitride nanosheets are modified before use, and the modified two-dimensional boron nitride nanosheets obtained are from Preparation Example 7.
[0064] Comparative Example Comparative Example 1 A method for preparing ultra-low temperature drift high-power alloy resistors differs from Example 1 in that two-dimensional boron nitride nanosheets are not used in the operation.
[0065] Comparative Example 2 A method for preparing an ultra-low temperature drift high-power alloy resistor differs from Example 1 in that a composite metallization layer is not formed during the operation.
[0066] Performance testing Test samples: The ultra-low temperature drift high power alloy resistors prepared by the method in Examples 1-20 were used as test samples 1-20, and the ultra-low temperature drift high power alloy resistors prepared by the method in Comparative Examples 1-2 were used as control samples 1-2.
[0067] Test method: (1) Temperature coefficient (TCR) test, refer to IEC 60115-1. The test equipment includes high-precision LCR digital bridge, programmable high and low temperature test chamber, and four-wire test fixture; the resistor is placed in the high and low temperature test chamber, and the resistance value change is monitored in real time using the four-wire method. The test temperature range is -55℃ to 155℃. After recording the data, the TCR is calculated.
[0068] (2) Power density test. Power density is the power borne by a unit volume or unit area. Here, it is expressed as the power borne by a unit volume. The maximum power that can be withstood is tested at an ambient temperature of 70℃: First, the sample is placed in a test chamber that has been stabilized at 70℃. No power is applied. After it reaches thermal equilibrium, the sample is taken out and cooled to room temperature of 25℃. Its initial resistance in the cold state is measured as the benchmark for the final comparison. Then, the sample is placed back in the 70℃ ambient chamber. Starting from a power level of 1W, it is maintained for a period of time until thermal stability is achieved (i.e., the surface temperature no longer rises). The sample is taken out and cooled to room temperature of 25℃. Its final resistance in the cold state is measured. Then, the rate of change of the relative initial resistance in the cold state ΔR is calculated. If ΔR > ±1%, the current power is determined to be the maximum power that can be withstood. Finally, the power density is calculated.
[0069] Take samples and test the temperature coefficient (TCR) and power density obtained by the above method, and record them as initial values. If the sample is placed in a programmable high and low temperature chamber, set the cycle program on the high and low temperature chamber controller as follows: -55℃ (stay for 30 min) → heating (10℃ / min) → +175℃ (stay for 30 min) → cooling (15℃ / min), cycle 1000 times. The pause point should be set at the end of the 25℃ stay phase. Then, perform the above temperature coefficient (TCR) and power density test in the same way and record them as cycle values. Finally, calculate ΔTCR and power density loss rate, where ΔTCR = |Temperature coefficient cycle value - Temperature coefficient initial value|, and power density loss rate = (Power density initial value - Power density cycle value) / Power density initial value. The smaller the above values, the better the stability.
[0070] After performing the above tests on test samples 1-20 and control samples 1-2, the test results are recorded in Table 2.
[0071] Table 2 Test results of test sample 1-20 and control sample 1-2 It should be noted that the above-mentioned test samples 1-20 were tested and found to have a TCR ≤ 8 ppm / ℃ within the temperature range of -55℃ to 155℃, and could withstand power of over 2W at an ambient temperature of 70℃, with a volumetric power density of 0.9-1.2 W / mm². 3 It has a high power density and excellent balance between ultra-low temperature drift and high power density.
[0072] As can be seen from Examples 1-13 and Comparative Examples 1-2, and Table 2, this application, by setting a composite metallization layer composed of titanium, two-dimensional boron nitride nanosheets, and nickel between the alumina ceramic substrate and the alloy foil, not only constructs an efficient planar heat conduction path during application, but also protects the microstructure of the resistive alloy foil through stress buffering. This results in a significant reduction in both ΔTCR and high power density loss rate of the alloy resistor after the aforementioned tests, indicating a better balance between ultra-low temperature drift and high power density. It cleverly resolves the contradiction between the thermal stress caused by high power density and the material stability required for ultra-low TCR. If two-dimensional boron nitride nanosheets are not used in the composite metallization layer, the effect of the composite metallization layer is significantly reduced. Therefore, two-dimensional boron nitride nanosheets play a prominent role in the process.
[0073] Combining Examples 1 and 14-20 with Table 2, it can be seen that by modifying the two-dimensional boron nitride nanosheets before use, this application found that the composite metallization layer using the modified two-dimensional boron nitride nanosheets can achieve better corresponding effects. The ΔTCR and high power density loss rate obtained by the above tests are further reduced, indicating that the ultra-low temperature drift high power alloy resistor has been further improved in terms of the balance and performance of ultra-low temperature drift and high power density.
[0074] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. A method for preparing an ultra-low temperature drift high-power alloy resistor, characterized in that, Includes the following steps: (1) A master alloy containing nickel, chromium, aluminum, silicon, manganese, copper and iron is prepared by vacuum induction melting and rolled into alloy foil; (2) An alumina ceramic substrate is selected, and its surface is treated to form a micron-level roughened surface and trenches with a predetermined pattern. Then, a titanium layer is deposited on the roughened surface and in the trenches, and a two-dimensional boron nitride nanosheet aerosol is introduced. At the same time, Ar is applied. + Ion bombardment is performed to embed two-dimensional boron nitride nanosheets into a nickel layer, followed by nickel layer deposition to finally form a composite metallization layer, resulting in a pretreated alumina ceramic substrate. (3) The alloy foil obtained in step (1) is temporarily fixed on the pretreated alumina ceramic substrate obtained in step (2), and after being cut to form a preset resistance pattern, it is sintered to obtain a semi-finished alloy resistor. (4) After the alloy resistor semi-finished product obtained in step (3) is subjected to controlled oxidation and passivation treatment, the end face is electroplated with electrodes to obtain an ultra-low temperature drift high power alloy resistor.
2. The method for preparing ultra-low temperature drift high-power alloy resistors according to claim 1, characterized in that: In step (2), the volume fraction of two-dimensional boron nitride nanosheets in the composite metallization layer is 2-3%, the thickness of the two-dimensional boron nitride nanosheets is 3-5 nm, and the lateral dimension is 50-200 nm.
3. The method for preparing ultra-low temperature drift high-power alloy resistors according to claim 1, characterized in that: In step (2), the titanium layer is deposited with a thickness of 50-60 nm and the nickel layer is deposited with a thickness of 180-220 nm.
4. The method for preparing ultra-low temperature drift high-power alloy resistors according to claim 1, characterized in that: In step (2), the two-dimensional boron nitride nanosheets are modified before use, including the following modification steps: S1. Two-dimensional boron nitride nanosheets, graphene oxide, and yttrium nitrate are dispersed together in a mixed solvent of deionized water and ethanol, and then ultrasonically formed into a uniform suspension. S2, 3-aminopropyltriethoxysilane and urea are added to the uniform suspension obtained in step S1. After adjusting the pH, the mixture is transferred to a reaction vessel for a one-pot heating reaction. After the reaction is completed, the mixture is allowed to cool naturally. The product is then collected by centrifugation and washed and annealed to obtain modified two-dimensional boron nitride nanosheets.
5. The method for preparing ultra-low temperature drift high-power alloy resistors according to claim 4, characterized in that: The weight mixing ratio of the two-dimensional boron nitride nanosheet raw material, graphene oxide and yttrium nitrate is (9-12):(0.4-0.6):
1.
6. The method for preparing ultra-low temperature drift high-power alloy resistors according to claim 4, characterized in that: In step S2, the temperature of the one-pot heating reaction is 180-220℃, and the reaction time is 16-24h.
7. The method for preparing ultra-low temperature drift high-power alloy resistor according to claim 1, characterized in that: In step (1), the alloy foil comprises the following components in parts by weight: 45-50 parts nickel; Chromium 20-25 parts; 4-6 parts aluminum; Silicon 1.5-2.5 parts; 2-3 parts manganese; 3-5 parts copper; Iron 10-15 parts.
8. The method for preparing ultra-low temperature drift high-power alloy resistor according to claim 1, characterized in that: In step (1), the thickness of the alloy foil is 1.8-2.2 μm.
9. The method for preparing ultra-low temperature drift high-power alloy resistor according to claim 1, characterized in that: In step (3), sintering is carried out in a nitrogen atmosphere containing 5% H2, with a sintering temperature of 700-750℃ and a sintering time of 10-15min.
10. The method for preparing ultra-low temperature drift high-power alloy resistor according to claim 1, characterized in that: In step (4), in a mixture containing 5% O 2 Controllable oxidation and passivation treatment is performed in a nitrogen atmosphere at a temperature of 500-550℃ for 20-30 minutes.