Preparation method of thin-film resistor

Abstract

The invention discloses a preparation method of a thin-film resistor, and the method comprises the following steps: S1, preparing a lead formula which comprises 85% of silver, 10% of nickel, 1% of chromium and other additives, and the other additives are selected from one or more of rare earth elements, boron, carbon, nitrogen and oxygen; s2, preparing the lead wire of the sheet resistor from the lead wire formula through a specific process, wherein the specific process comprises smelting, forming and surface treatment; s3, the conductive performance of the resistor is achieved through connection of the lead and the sheet resistor, the connection mode comprises welding, crimping or bonding, by using domestic materials, the cost is reduced, and the localization level of the sheet resistor is improved; compared with a traditional nickel core platinum-plated layer lead, the alloy lead has the advantages of being smaller in size, shorter in thermal response time, higher in temperature stability and better in high-temperature stability. The sheet resistor can be widely applied to various electronic devices.

Description

Technical Field

[0001] The invention belongs to the technical field of thin film resistors, and in particular relates to a method for preparing a thin film resistor. Background Art

[0002] In the traditional manufacturing process of thin-film resistor leads, in order to improve the oxidation resistance of the leads and prevent oxidation during welding, the nickel core plating layer is usually used. Nickel has high chemical stability and good conductivity, while the platinum layer provides additional protection to prevent nickel from being oxidized during welding. However, there are some significant problems with this material and process: High cost: Platinum is a precious metal, which is expensive, resulting in high material costs for using platinum as a plating layer. Complex preparation process: The electroplating process of the platinum layer requires precise control of parameters such as current density, pH value, temperature and electroplating time to ensure the uniformity and adhesion of the plating layer. Difficulty in localization: Due to technical barriers and dependence on imports of key materials, it is challenging to achieve localization of this material. Limited performance improvement: In the pursuit of higher performance electronic devices, traditional nickel core platinum plating may not meet higher oxidation resistance and heat resistance requirements. To overcome these problems, research and development of new antioxidant materials and simplified preparation processes are necessary. This may include exploring alternative antioxidant materials, improving electroplating processes, developing new alloy materials, or looking for coating materials with better performance. These efforts can reduce costs, simplify process flows, and promote the localization of thin-chip resistor lead materials, thereby improving the performance and reliability of electronic devices. Summary of the invention

[0003] To achieve the above object, the technical solution of the present invention is as follows: a method for preparing a thin film resistor, the method comprising the following steps: Step S1, preparing a lead wire formula, wherein the lead wire formula includes 85% silver, 10% nickel, and 1% chromium, and other additives, wherein the other additives are selected from one or more of rare earth elements, boron, carbon, nitrogen, and oxygen; Step S2, preparing the lead wire formula into the lead wire of the chip resistor through a specific process, wherein the specific process includes melting, forming, and surface treatment; Step S3, using the lead wire to connect with the thin-film resistor to achieve the conductive performance of the resistor, wherein the connection method includes welding, crimping or bonding.

[0004] Based on the above technical solution, in the present invention, silver is selected as the main material, accounting for 85 weight percent of the lead formula, nickel is added, accounting for 10 weight percent of the lead formula, chromium is added, accounting for 1 weight percent of the lead formula, and one or more of rare earth elements, boron, carbon, nitrogen, and oxygen are selectively added as other additives, and the total content of the other additives does not exceed 5 weight percent. The silver, nickel, chromium and other additives are mixed evenly to form a lead formula, and the lead formula is smelted under the protection of an inert gas to form a molten metal. The molten metal is formed into a lead through a molding process, and the molded lead is surface treated to improve its oxidation resistance. The proportion of silver, nickel, chromium and other alloys in the lead formula can be adjusted according to actual needs to meet different resistance performance requirements.

[0005] As an improvement of the present invention, other additives in the lead wire formula are used to improve the welding performance and anti-oxidation performance of the lead wire, and the total content of the other additives does not exceed 5%.

[0006] As an improvement of the present invention, steps S1 to S4 include the following steps: Step S1, 85 weight percent of silver, 10 weight percent of nickel, 1 weight percent of chromium, and one or more additives selected from rare earth elements, boron, carbon, nitrogen, and oxygen are mixed in the following weight percentages to form a lead formula: 0.5-2% of rare earth elements, 0.1-0.5% of boron, 0.05-0.2% of carbon, 0.01-0.1% of nitrogen, and 0.01-0.05% of oxygen; Step S2, under the protection of an inert gas, melting the lead wire formula at a temperature of 1000-1200 degrees Celsius to form a molten metal; Step S3, forming the molten metal into a lead wire with a diameter of 0.1-1 mm through an extrusion molding process; Step S4, performing surface treatment on the formed lead wire, wherein the surface treatment comprises electroplating nickel or gold on the surface of the lead wire with a thickness of 0.01-0.1 micrometers.

[0007] Based on the above technical solution, the lead wire formula of the present invention includes 85% silver, 10% nickel, about 1% chromium, and other additives. This alloy formula not only has good electrical conductivity, but also can effectively prevent oxidation during welding.

[0008] As an improvement of the present invention, in step S2, the inert gas is selected from argon, helium or xenon.

[0009] As an improvement of the present invention, the molding process in step S3 specifically includes the following steps: extruding the molten metal through a mold into a lead of a desired shape, and annealing the extruded lead to eliminate internal stress.

[0010] Based on the above technical solution, the smelted alloy is processed through a specific forming process, such as extrusion, stretching, etc., to prepare the lead shape required for the thin-film resistor.

[0011] As an improvement of the present invention, the surface treatment step in step S4 includes polishing and cleaning the lead surface before electroplating to improve the adhesion of the electroplating layer, and heat treating the lead after electroplating to enhance the bonding strength between the electroplating layer and the substrate.

[0012] As an improvement of the present invention, the surface treatment in step S4 includes electroplating nickel or gold on the surface of the lead with a thickness of 0.01-0.1 microns, wherein the electroplating process is controlled by a constant current power supply or a constant voltage power supply to ensure uniform deposition of metal ions.

[0013] As an improvement of the present invention, the thickness of the electroplated nickel or gold in step S4 is measured by X-ray fluorescence or microscopic observation, and the electroplating solution contains a specific pH buffer, a wetting agent and an additive.

[0014] As an improvement of the present invention, the step S4 further includes passivating the lead after electroplating to form a dense protective film.

[0015] As an improvement of the present invention, the method also includes performing performance tests on the prepared thin-film resistor to ensure that it has a small size, a short thermal response time, a high temperature stability and good high-temperature stability, wherein the performance tests include but are not limited to size measurement, thermal response time testing, temperature stability testing and high-temperature stability testing.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention reduces costs and improves the localization level of thin-film resistors by using domestic materials; compared with traditional nickel-core platinum-plated leads, the alloy leads of the present invention have smaller volume, faster thermal response time, higher temperature stability and better high-temperature stability; the thin-film resistors of the present invention can be widely used in various electronic devices, such as sensors, measuring instruments, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the process of preparing the thin film resistor in Example 1; Figure 2 Schematic diagram of the process of preparing the thin film resistor in Example 2. DETAILED DESCRIPTION

[0018] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0019] Example 1: Figure 1 As shown, a method for preparing a thin film resistor comprises the following steps: Step S1, preparing a lead wire formula, wherein the lead wire formula includes 85% silver, 10% nickel, and 1% chromium, and other additives, wherein the other additives are selected from one or more of rare earth elements, boron, carbon, nitrogen, and oxygen; Step S2, preparing the lead wire formula into the lead wire of the chip resistor through a specific process, wherein the specific process includes melting, forming, and surface treatment; Step S3, using the lead wire to connect with the thin-film resistor to achieve the conductive performance of the resistor, wherein the connection method includes welding, crimping or bonding.

[0020] In this embodiment, silver is selected as the main material, accounting for 85 weight percent of the lead formula, nickel is added, accounting for 10 weight percent of the lead formula, chromium is added, accounting for 1 weight percent of the lead formula, and one or more of rare earth elements, boron, carbon, nitrogen, and oxygen are selectively added as other additives, and the total content of the other additives does not exceed 5 weight percent. The silver, nickel, chromium and other additives are mixed evenly to form a lead formula, the lead formula is smelted under the protection of an inert gas to form a molten metal, the molten metal is made into a lead through a molding process, and the molded lead is surface treated to improve its oxidation resistance.

[0021] Furthermore, other additives in the lead wire formula are used to improve the welding performance and anti-oxidation performance of the lead wire, and the total content of the other additives does not exceed 5%.

[0022] Furthermore, if Figure 2 As shown in Example 2, a method for preparing a thin film resistor comprises the following steps: Step S1, 85 weight percent of silver, 10 weight percent of nickel, 1 weight percent of chromium, and one or more additives selected from rare earth elements, boron, carbon, nitrogen, and oxygen are mixed in the following weight percentages to form a lead formula: 0.5-2% of rare earth elements, 0.1-0.5% of boron, 0.05-0.2% of carbon, 0.01-0.1% of nitrogen, and 0.01-0.05% of oxygen; Step S2, under the protection of an inert gas, melting the lead wire formula at a temperature of 1000-1200 degrees Celsius to form a molten metal; Step S3, forming the molten metal into a lead wire with a diameter of 0.1-1 mm through an extrusion molding process; Step S4, surface treatment is performed on the formed lead wire, and the surface treatment includes electroplating nickel or gold on the lead wire surface with a thickness of 0.01-0.1 micrometers. The lead wire formula of this embodiment includes 85% silver, 10% nickel, about 1% chromium, and other additives. This alloy formula not only has good electrical conductivity, but also can effectively prevent oxidation during the welding process.

[0023] Furthermore, in step S2, the inert gas is selected from one of argon, helium or xenon.

[0024] Furthermore, the forming process in step S3 specifically includes the following steps: extruding the molten metal into a lead of a desired shape through a die, annealing the extruded lead to eliminate internal stress, and preparing the smelted alloy into the lead shape required for the chip resistor through a specific forming process, such as extrusion, stretching, etc.

[0025] Furthermore, the surface treatment step in step S4 includes polishing and cleaning the surface of the lead before electroplating to improve the adhesion of the electroplating layer, and heat treating the lead after electroplating to enhance the bonding strength between the electroplating layer and the substrate.

[0026] Furthermore, the surface treatment in step S4 includes electroplating nickel or gold on the surface of the lead with a thickness of 0.01-0.1 micrometers, wherein the electroplating process is controlled by a constant current power supply or a constant voltage power supply to ensure uniform deposition of metal ions.

[0027] Furthermore, the thickness of the electroplated nickel or gold in step S4 is measured by X-ray fluorescence or microscopic observation, and the electroplating solution contains a specific pH buffer, a wetting agent and an additive.

[0028] Furthermore, the step S4 also includes passivation treatment of the lead after electroplating to form a dense protective film.

[0029] Furthermore, the method also includes performing performance tests on the prepared thin-film resistor to ensure its small size, short thermal response time, high temperature stability and good high-temperature stability, wherein the performance tests include but are not limited to size measurement, thermal response time test, temperature stability test and high-temperature stability test.

[0030] Performance test: The assembled resistor assembly was subjected to a performance test. After the test, the resistor prepared in this embodiment met the following performance: volume: 1.9×2mm, the limit size is 1.2×2mm; thermal response time: 0.1 second; temperature stability: the ratio is between 1.388-1.387; high temperature stability: suitable for a temperature range of 300-500°C.

[0031] By using domestic materials, the cost is reduced and the localization level of the thin-film resistor is improved; compared with the traditional nickel-core platinum-plated lead, the alloy lead of the present invention has a smaller volume, a faster thermal response time, a higher temperature stability and better high-temperature stability; the thin-film resistor of the present invention can be widely used in various electronic devices, such as sensors, measuring instruments, etc.

[0032] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a thin film resistor, characterized in that: The method comprises the following steps, Step S1, preparing a lead wire formula, wherein the lead wire formula includes 85% silver, 10% nickel, and 1% chromium, and other additives, wherein the other additives are selected from one or more of rare earth elements, boron, carbon, nitrogen, and oxygen; Step S2, preparing the lead wire formula into the lead wire of the chip resistor through a specific process, wherein the specific process includes melting, forming, and surface treatment; Step S3, using the lead wire to connect with the thin-film resistor to achieve the conductive performance of the resistor, wherein the connection method includes welding, crimping or bonding.

2. The method for preparing a thin film resistor according to claim 1, characterized in that: The other additives in the lead wire formula are used to improve the welding performance and anti-oxidation performance of the lead wire, and the total content of the other additives does not exceed 5%.

3. The method for preparing a thin film resistor according to claim 1, characterized in that: The steps S1 to S4 include the following steps: Step S1, 85 weight percent of silver, 10 weight percent of nickel, 1 weight percent of chromium, and one or more additives selected from rare earth elements, boron, carbon, nitrogen, and oxygen are mixed in the following weight percentages to form a lead formula: 0.5-2% of rare earth elements, 0.1-0.5% of boron, 0.05-0.2% of carbon, 0.01-0.1% of nitrogen, and 0.01-0.05% of oxygen; Step S2, under the protection of an inert gas, melting the lead wire formula at a temperature of 1000-1200 degrees Celsius to form a molten metal; Step S3, forming the molten metal into a lead wire with a diameter of 0.1-1 mm through an extrusion molding process; Step S4, performing surface treatment on the formed lead wire, wherein the surface treatment comprises electroplating nickel or gold on the surface of the lead wire with a thickness of 0.01-0.1 micrometers.

4. The method for preparing a thin film resistor according to claim 3, characterized in that: In step S2, the inert gas is selected from argon, helium or xenon.

5. The method for preparing a thin film resistor according to claim 3, characterized in that: The molding process in step S3 specifically includes the following steps: The molten metal is extruded through a die into a lead of the desired shape, and the extruded lead is annealed to eliminate internal stress.

6. The method for preparing a thin film resistor according to claim 3, characterized in that: The surface treatment step in step S4 includes grinding and cleaning the surface of the lead before electroplating to improve the adhesion of the electroplating layer, and heat treating the lead after electroplating to enhance the bonding strength between the electroplating layer and the substrate.

7. The method for preparing a thin film resistor according to claim 3, characterized in that: The surface treatment in step S4 includes electroplating nickel or gold on the surface of the lead wire with a thickness of 0.01-0.1 micrometers, wherein the electroplating process is controlled by a constant current power supply or a constant voltage power supply to ensure uniform deposition of metal ions.

8. The method for preparing a thin film resistor according to claim 3, characterized in that: The thickness of the electroplated nickel or gold in step S4 is measured by X-ray fluorescence or microscopic observation, and the electroplating solution contains a specific pH buffer, a wetting agent and an additive.

9. The method for preparing a thin film resistor according to claim 3, characterized in that: The step S4 also includes passivation treatment of the lead after electroplating to form a dense protective film.

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