CN103643085B - Embed type film resistor material and preparation method thereof - Google Patents

Abstract

The present invention relates to a kind of embed type film resistor material and preparation method thereof.This embed type film resistor material presses atomic percentage, comprises nickel 50 ~ 76%, chromium 10 ~ 18%, carbon 10 ~ 30% and tungsten 0.5 ~ 5%.By magnetron sputtering technique nickel, chromium, carbon and tungsten atom be deposited on Copper Foil substrate and obtain nickel chromium triangle carbon W film, our experiments show that, use the electrical property of the embed type thin film resistor device of this nickel chromium triangle carbon W film more stable, sheet resistance value is higher.

Description

Embedded thin film resistive material and preparation method thereof

technical field

The invention relates to the technical field of electronic materials and electronic components, in particular to an embedded thin film resistance material and a preparation method thereof.

Background technique

The development trend of high performance and miniaturization of electronic components requires that the number of electronic components mounted per unit area of printed circuit boards continues to increase, resulting in supersaturation of the surface area of printed circuit boards. Compared with traditional discrete resistors, embedded thin film resistors (buried resistors) can save wiring distance, reduce the number of mounted components, reduce the size and weight of circuit boards; and can reduce parasitic inductance and surface resistance during signal transmission. Inductive reactance generated during placement or plug-in processing; can improve the impedance matching ability of the line; can reduce signal crosstalk, noise and electromagnetic interference. The embedded thin film resistor device has high reliability, stable resistance value and low loss. The embedded thin film resistor device is to press and paste the thin film resistor material on a special semi-cured resin board, form a thin film resistor after etching, and then laminate it into the inside of the printed circuit board.

Representative embedded thin film resistor materials abroad include: Ohmega Ply’s NiP buried resistor material produced by electroplating, and GOULD Electronics’ NiCr produced by magnetron sputtering. These materials have small square resistance tolerances and stable electrical properties. , but the square resistance value is too small, the scope of use is limited, and there is still room for improvement in all aspects of performance. Domestically, embedded thin film resistor materials are mostly in the research and development stage, and have not yet fully entered industrialization.

Contents of the invention

Based on this, it is necessary to provide an embedded thin film resistor material capable of improving the electrical performance stability of the embedded thin film resistor device and increasing the square resistance value.

An embedded thin film resistive material comprising, by atomic percent:

50-76% nickel, 10-18% chromium, 10-30% carbon and 0.5-5% tungsten.

An embedded thin-film resistance material, comprising a nickel-chromium-carbon-tungsten film, and the elements of the nickel-chromium-carbon-tungsten film include 50-76% of nickel, 10-18% of chromium, 10-30% of carbon and tungsten 0.5~5%.

In one of the embodiments, a substrate is also included, and the nickel-chromium-tungsten carbon thin film is deposited on the substrate.

In one embodiment, the substrate is a low-profile flexible copper foil.

In one embodiment, the nickel-chromium-tungsten film has a thickness of 85 nm to 200 nm.

A method for preparing an embedded thin film resistance material, comprising the steps of:

provide the substrate; and

A nickel-chromium-carbon-tungsten thin film is formed on the substrate by a sputtering method to obtain an embedded thin-film resistance material, wherein the elements of the nickel-chromium-carbon-tungsten thin film include nickel 50-76%, chromium 10 ～18%, carbon 10～30% and tungsten 0.5～5%.

In one embodiment, after the step of forming the nickel-chromium-tungsten-carbon thin film on the substrate by sputtering, the step of annealing the nickel-chromium-tungsten carbon thin film at high temperature is further included.

In one embodiment, the high-temperature annealing step is annealing at 250° C. to 400° C. for 480 seconds to 720 seconds in a protective gas atmosphere.

In one of the embodiments, the step of forming a nickel-chromium-carbon-tungsten film on the substrate by sputtering is to use a nickel-chromium alloy target, a carbon target and a tungsten target, and combine nickel-chromium, carbon and tungsten sputtering onto the substrate, and depositing a nickel-chromium-tungsten carbon thin film on the substrate.

In one of the embodiments, in the step of forming a nickel-chromium-carbon-tungsten film on the substrate by sputtering, the current of the nickel-chromium alloy target is 2-5 amps, and the current of the carbon target is The current is 1-1.5 A, and the current of the tungsten target is 0.1-0.3 A.

In one of the embodiments, in the step of forming a nickel-chromium-tungsten thin film on the substrate by sputtering, a bias voltage of 30 volts to 120 volts is applied to the substrate.

In one embodiment, in the step of forming a nickel-chromium-tungsten thin film on the substrate by sputtering, the substrate is rotated at a speed of 4 revolutions per minute.

The embedded thin-film resistor material includes 50-76% nickel, 10-18% chromium, 10-30% carbon and 0.5-5% tungsten in atomic percentage. Nickel, chromium, carbon, and tungsten atoms are deposited on a copper foil substrate by magnetron sputtering technology to obtain a nickel-chromium-carbon-tungsten film. Experiments show that the electrical properties of the embedded thin-film resistance device using the nickel-chromium-carbon-tungsten film More stable, higher square resistance.

Description of drawings

Fig. 1 is the flow chart of the preparation method of the embedded type thin film resistive material of an embodiment;

Fig. 2 is the variation curve of temperature coefficient of resistance (TCR) of the embedded type thin film resistance material of embodiment 1 and the embedded type thin film resistance material of comparative example 1 (TCR) with temperature;

Fig. 3 is the variation curve of temperature coefficient of resistance (TCR) of the buried type thin film resistance material of embodiment 2 and the buried type thin film resistance material of comparative example 2 with temperature;

Fig. 4 is the variation curve of temperature coefficient of resistance (TCR) of the buried type thin film resistance material of embodiment 3 and the buried type thin film resistance material of comparative example 1 with temperature;

Fig. 5 is the variation curve of temperature coefficient of resistance (TCR) of the buried type thin film resistance material of embodiment 4 and the buried type thin film resistance material of comparative example 2 with temperature;

Fig. 6 is the polarization curve of the buried type thin film resistance material of embodiment 1 and the buried type thin film resistance material of comparative example 1;

Fig. 7 is the polarization curve of the buried type thin film resistance material of embodiment 2 and the buried type thin film resistance material of comparative example 2;

Fig. 8 is the SEM topography figure of the nickel-chromium-carbon-tungsten (NiCrCW) film prepared in Example 1 immersed in 60% H2SO4 for 85 hours;

FIG. 9 is a SEM image of the nickel-chromium (NiCr) film prepared in Comparative Example 1 soaked in H2SO4 with a concentration of 60% by mass for 85 hours.

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, specific implementations of the present invention will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present invention, so the present invention is not limited by the specific implementations disclosed below.

An embedded thin film resistor material according to one embodiment includes 50-76% nickel, 10-18% chromium, 10-30% carbon, and 0.5-5% tungsten in atomic percent.

The nickel-chromium-tungsten-carbon thin film is prepared by using the above-mentioned alloy material, and the nickel-chromium-tungsten thin film can be used to prepare embedded thin-film resistance devices with relatively stable electrical properties and high square resistance.

Another embodiment of the embedded thin film resistor material includes nickel chromium tungsten carbon thin film.

The material of nickel-chromium-tungsten carbon film is nickel (Ni) and chromium (Cr) as the main material, doped with an appropriate amount of carbon (C) and tungsten (W). Among them, by atomic percentage, nickel accounts for 50-76%, chromium accounts for 10-18%, carbon accounts for 10-30%, and tungsten accounts for 0.5%-5%.

Preferably, the thickness of the nickel-chromium-tungsten carbon thin film is 85 nanometers to 200 nanometers.

The nickel-chromium-tungsten-carbide film uses Ni and Cr as the main materials, and is doped with an appropriate amount of C element and a small amount of W element, so that the nickel-chromium-carbide-tungsten film has stable electrical properties, large square resistance, high hardness, good Excellent corrosion resistance and wear resistance, better performance than existing nickel-chromium thin film resistor materials.

Carbon element exists in nickel-chromium-carbon-tungsten film mainly in the form of mixed structure of amorphous and nanocrystalline, and their mixed interface can promote the diffusion of chromium in nickel-chromium alloy, so that chromium is more likely to form dense chromium trioxide on the surface The protective film makes the nickel-chromium-tungsten film have higher corrosion resistance.

The chemical properties of tungsten element are stable. Even under the condition of heating, it will not interact with strong acids such as hydrochloric acid and sulfuric acid, and will not even dissolve in aqua regia. Only a mixture of highly corrosive hydrofluoric acid and nitric acid can dissolve tungsten. The tungsten element further improves the corrosion resistance of the nickel-chromium-tungsten carbon film.

Preferably, the embedded thin-film resistance material further includes a substrate, on which the nickel-chromium-tungsten carbon thin film is deposited.

The substrate is a ceramic substrate or a metal substrate, preferably a low profile (VLP) flexible copper foil. The two opposite surfaces of the low-profile flexible copper foil are a smooth surface and a rough surface respectively, and the roughness of the rough surface is relatively uniform.

Preferably, the nickel-chromium-tungsten-carbon thin film is deposited on the rough surface of the low-profile flexible copper foil, which can not only increase the square resistance of the nickel-chromium-tungsten thin film, but also improve the bonding force between the nickel-chromium-tungsten thin film and the substrate, which is beneficial to An embedded thin film resistor device with high square resistance and good stability is prepared.

Experiments have shown that the above-mentioned embedded thin film resistance material has high electrical performance stability and high square resistance value, and has high hardness, high corrosion resistance and high wear resistance, making the material Embedded thin film resistor materials have high application value and wide application range.

When the embedded thin film resistance material is used, the embedded thin film resistance material is etched to obtain the required buried resistance device, and then laminated into the printed circuit board.

After the nickel-chromium-tungsten carbon film is etched into a buried resistance device, the low-profile flexible copper foil retained at both ends of the buried resistance can be used as an electrode of the buried resistance, which saves the additional steps of preparing electrodes and is conducive to reducing costs.

Moreover, using low-profile (VLP) flexible copper foil as a substrate, when preparing nickel-chromium-tungsten carbon thin films, coil-wound coatings can be realized, which is suitable for industrial production.

Please refer to FIG. 1, a method for preparing an embedded thin-film resistance material in an embodiment includes the following steps:

Step S110: providing a substrate.

The substrate is preferably a low profile flexible copper foil.

The substrate was ultrasonically cleaned in anhydrous acetone, anhydrous ethanol, and deionized water for 10 minutes each, then blown dry with a nitrogen gun, and then flattened with a clean glass plate for use.

Step S120: Form a nickel-chromium-tungsten-carbon thin film on the substrate by sputtering to obtain an embedded thin-film resistance material, wherein the elements of the nickel-chromium-tungsten thin film include nickel 50-76%, chromium 10- 18%, carbon 10-30% and tungsten 0.5-5%.

Place the nickel-chromium alloy target (NiCr) in the cathode target position 1 of the vacuum sputtering chamber, the carbon target (C) in the cathode target position 2, and the tungsten target (W) in the cathode target position 3, and put the substrate Fixed on the rotating workpiece holder.

Among them, the atomic ratio of nickel and chromium in the nickel-chromium alloy target is 4:1. The purity of nickel-chromium alloy target, carbon target and tungsten target is 99.99%.

The vacuum sputtering chamber is sealed, and the vacuum degree of the vacuum sputtering chamber reaches 3.0×10 ^-5 to 4.5×10 ^-5 Torsola through a vacuum pumping system. Introduce argon gas, the gas flow rate is 25-30 sccm, when the pressure of the vacuum sputtering chamber reaches 1.1×10 ^-3 ～1.5×10 ^-3 Torsla, start the ionization power supply, ionize and clean the substrate surface, and the cleaning time is 5 to 10 minutes, then turn on the sputtering power supply of the three targets of nickel-chromium alloy target, carbon target and tungsten target at room temperature, and after 5 to 10 minutes of pre-sputtering, turn on the rotary switch of the rotary The workpiece holder rotates and drives the substrate to rotate, sputtering for 4 to 16 minutes, nickel-chromium-tungsten carbon is deposited on the substrate, thereby forming a nickel-chromium-carbon-tungsten film on the substrate.

Pre-sputter for 5 to 10 minutes before sputtering to remove dust on the surface of each target, which is conducive to obtaining a good quality nickel-chromium-carbon-tungsten film.

Preferably, during the sputtering process, the current of the nickel-chromium alloy target is 2-5 amps, the current of the carbon target is 1-1.5 amps, and the current of the tungsten target is 0.1-0.3 amps.

Preferably, during the sputtering process, a bias voltage of 30 volts to 120 volts is applied to the substrate.

Preferably, during the sputtering process, the rotation speed of the substrate is 4 rpm.

The current of the nickel-chromium alloy target is 2-5 amps, the current of the carbon target is 1-1.5 amps, the current of the tungsten target is 0.1-0.3 amps, and a bias voltage of 30 volts to 120 volts is applied on the substrate and the lining Sputtering nickel-chromium, carbon and tungsten under the sputtering condition with the rotation speed of the bottom being 4 revolutions per minute is conducive to forming a nickel-chromium-carbon-tungsten thin film with high density and few defects.

Preferably, the closed-field unbalanced magnetron sputtering technique is used for sputtering. Compared with the traditional balanced magnetron sputtering, the nickel-chromium-tungsten-carbon thin film formed by closed-field unbalanced magnetron sputtering is denser, has fewer defects, and has higher quality. Moreover, the closed-field unbalanced magnetron sputtering technology is used for sputtering, which is conducive to improving the bonding force between the nickel-chromium-tungsten film and the substrate.

Preferably, after the nickel-chromium-tungsten-carbon thin film is formed on the substrate by the sputtering method, the step of annealing the nickel-chromium-tungsten thin film at high temperature is also included.

The step of high-temperature annealing is preferably annealing at 250° C. to 400° C. for 480 seconds to 720 seconds in a protective gas atmosphere.

After sputtering is completed and cooled by circulating water, the nickel-chromium-tungsten-carbon film deposited on the substrate is taken out from the vacuum sputtering chamber, and put into RTP-500 rapid thermal processing equipment for annealing treatment. The annealing condition is rapid annealing at 250° C. to 400° C. for 480 seconds to 720 seconds under a protective gas atmosphere, and the annealed embedded thin film resistor material is taken out after cooling.

Among them, the elements of the nickel-chromium-tungsten carbon thin film are calculated by atomic percentage, including 50-76% nickel, 10-18% chromium, 10-30% carbon and 0.5-5% tungsten.

The shielding gas is an inert gas such as nitrogen, argon, helium, etc., preferably nitrogen.

Annealing at 250° C. to 400° C. for 480 seconds to 720 seconds, the obtained nickel-chromium-carbon-tungsten thin film has small stress, few defects, and stable electrical properties.

The preparation method of the embedded thin film resistance material has a simple process, and the prepared nickel-chromium-tungsten carbon thin film of the embedded thin film resistance material has high compactness, good uniformity, and high bonding force with the substrate. Moreover, this preparation method is suitable for large-area coating production and is beneficial to industrial production.

Further elaborate below by specific embodiment.

Example 1

Fabrication of embedded thin film resistor materials

(1) Ultrasonic clean the low-profile flexible copper foil with an area of 9cm×9cm in anhydrous acetone, anhydrous alcohol and deionized water for 10 minutes, then blow dry with a nitrogen gun, and then flatten it with a clean glass plate for use ;

(2) Place the flattened low-profile flexible copper foil on the rotating workpiece holder in the vacuum sputtering chamber, and close the vacuum sputtering chamber. Turn on the vacuum pumping system, when the vacuum degree of the vacuum sputtering chamber reaches 4.0×10 ^-5 Torsla, introduce argon gas, the gas flow rate is 25 sccm, start the ionization power supply, ionize and clean the substrate surface for 10 minutes, and immediately turn on the nickel The sputtering power supply of the three targets of chromium alloy target, carbon target and tungsten target is sputtered for 4 minutes to form a nickel-chromium-carbon-tungsten film deposited on the substrate. Among them, the target current of nickel-chromium alloy target, carbon target and tungsten target is set to 3A, 1A and 0.1A respectively, the bias voltage applied to the substrate is 90V, the substrate temperature is room temperature, and the workpiece is rotated The rotating speed of frame is set to 4 revolutions/minute;

(3) After the sputtering is completed and cooled by circulating water, take out the nickel-chromium-carbon-tungsten film deposited on the substrate from the vacuum sputtering chamber. The thickness of the nickel-chromium-carbon-tungsten film is about 91 nanometers. The elements of nickel-chromium-tungsten carbon film include nickel 65.0at.%, chromium 16.5at.%, carbon 17.6at.%, tungsten 0.9at.%.

Example 2

Fabrication of embedded thin film resistor materials

(1) Ultrasonic clean the low-profile flexible copper foil with an area of 9cm×9cm in anhydrous acetone, anhydrous alcohol and deionized water for 10 minutes, then blow dry with a nitrogen gun, and then flatten it with a clean glass plate for use ;

(2) Place the flattened low-profile flexible copper foil on the rotating workpiece holder in the vacuum sputtering chamber, and close the vacuum sputtering chamber. Turn on the vacuum pumping system, when the vacuum degree of the vacuum sputtering chamber reaches 4.0×10 ^-5 Torsla, introduce argon gas, the gas flow rate is 25 sccm, start the ionization power supply, ionize and clean the substrate surface for 10 minutes, and immediately turn on the nickel The sputtering power supply of the three targets of chromium alloy target, carbon target and tungsten target is sputtered for 4 minutes to form a deposited nickel-chromium-carbon-tungsten film deposited on the substrate. Among them, the target current of nickel-chromium alloy target, carbon target and tungsten target is set to 3A, 1A and 0.1A respectively, the bias voltage applied to the substrate is 90V, the substrate temperature is room temperature, and the workpiece is rotated The rotating speed of frame is set to 4 revolutions/minute;

(3) After the sputtering is completed and cooled by circulating water, take out the nickel-chromium-tungsten carbon film deposited on the substrate from the vacuum sputtering chamber. Put the nickel-chromium-carbon-tungsten thin film deposited on the substrate into RTP-500 type rapid heat treatment equipment for annealing treatment. The annealing conditions are: under nitrogen protection, anneal at 300°C for 540 seconds, and the obtained annealed nickel Chromium Carbon Tungsten Thin Film Resistor Material. Wherein, the thickness of the nickel-chromium-tungsten carbon film is 88.9 nanometers. The elements of the nickel-chromium-tungsten carbon film include nickel 62.7at.%, chromium 17.1at.%, carbon 19.4at.%, and tungsten 0.8at.%.

Example 3

Fabrication of embedded thin film resistor materials

(1) Ultrasonic clean the low-profile flexible copper foil with an area of 9cm×9cm in anhydrous acetone, anhydrous alcohol and deionized water for 10 minutes, then blow dry with a nitrogen gun, and then flatten it with a clean glass plate for use ;

(2) Place the flattened low-profile flexible copper foil on the rotating workpiece holder in the vacuum sputtering chamber, and close the vacuum sputtering chamber. Turn on the vacuum pumping system, when the vacuum degree of the vacuum sputtering chamber reaches 4.0×10 ^-5 Torsla, introduce argon gas, the gas flow rate is 25 sccm, start the ionization power supply, ionize and clean the substrate surface for 10 minutes, and immediately turn on the nickel The sputtering power supply of the chromium alloy target, the carbon target and the tungsten target is sputtered for 4 minutes to form a deposited nickel-chromium-carbon-tungsten film deposited on the substrate to obtain an embedded thin film resistance material. Among them, the target currents of nickel-chromium alloy target, carbon target and tungsten target are respectively set to 3 amps, 1.5 amps and 0.1 amps, the bias voltage applied to the substrate is 90 volts, the substrate temperature is room temperature, and the workpiece is rotated The rack speed was set at 4 rpm. Wherein, the thickness of the nickel-chromium-tungsten carbon film is 93.7 nanometers. The elements of nickel-chromium-tungsten carbon film include nickel 60.4at.%, chromium 14.6at.%, carbon 24.1at.%, tungsten 0.9at.%.

Example 4

Fabrication of embedded thin film resistor materials

(1) Ultrasonic clean the low-profile flexible copper foil with an area of 9cm×9cm in anhydrous acetone, anhydrous alcohol and deionized water for 10 minutes, then blow dry with a nitrogen gun, and then flatten it with a clean glass plate for use ;

(2) Place the flattened low-profile flexible copper foil on the rotating workpiece holder in the vacuum sputtering chamber, and close the vacuum sputtering chamber. Turn on the vacuum pumping system, when the vacuum degree of the vacuum sputtering chamber reaches 4.0×10 ^-5 Torsla, introduce argon gas, the gas flow rate is 25 sccm, start the ionization power supply, ionize and clean the substrate surface for 10 minutes, and immediately turn on the nickel The sputtering power supply of the chromium alloy target, the carbon target and the tungsten target is sputtered for 4 minutes to form a deposited nickel-chromium-carbon-tungsten film deposited on the substrate to obtain an embedded thin film resistance material. Among them, the target currents of nickel-chromium alloy target, carbon target and tungsten target are respectively set to 3 amps, 1.5 amps and 0.1 amps, the bias voltage applied to the substrate is 90 volts, the substrate temperature is room temperature, and the workpiece is rotated The rack speed was set at 4 rpm. Put the nickel-chromium-carbon-tungsten thin film deposited on the substrate into RTP-500 type rapid heat treatment equipment for annealing treatment. The annealing conditions are: under nitrogen protection, anneal at 300°C for 540 seconds, and the obtained annealed nickel Chromium Carbon Tungsten Thin Film Resistor Material. Wherein, the thickness of the nickel-chromium-tungsten carbon film is 91.5 nanometers. The elements of nickel-chromium-tungsten carbon film include nickel 60.1at.%, chromium 13.8at.%, carbon 25.3at.%, tungsten 0.8at.%.

Comparative example 1

Fabrication of embedded thin film resistor materials

(1) Ultrasonic clean the low-profile flexible copper foil with an area of 9cm×9cm in anhydrous acetone, anhydrous alcohol and deionized water for 10 minutes, then blow dry with a nitrogen gun, and then flatten it with a clean glass plate for use ;

(2) Place the flattened low-profile flexible copper foil on the rotating workpiece holder in the vacuum sputtering chamber, and close the vacuum sputtering chamber. Turn on the vacuum pumping system, when the vacuum degree of the vacuum sputtering chamber reaches 4.0×10 ^-5 Torsla, introduce argon gas, the gas flow rate is 25 sccm, start the ionization power supply, ionize and clean the substrate surface for 10 minutes, and immediately turn on the nickel Chromium alloy target sputtering power supply, sputtering for 4 minutes to form a deposited nickel-chromium film deposited on the substrate. The target current of the nickel-chromium alloy target is set to 3 amps, the bias voltage applied to the substrate is 90 volts, the substrate temperature is room temperature, and the rotating speed of the rotating workpiece holder is set to 4 revolutions per minute;

(3) After the sputtering is completed, after cooling by circulating water, take out the nickel-chromium film deposited on the substrate from the vacuum sputtering chamber. The thickness of the NiCr thin film is about 94.8 nm. The elements of the nickel-chromium thin film include nickel 78.9 at.% and chromium 21.1 at.% by atomic percentage.

Comparative example 2

Fabrication of embedded thin film resistor materials

(1) Ultrasonic clean the low-profile flexible copper foil with an area of 9cm×9cm in anhydrous acetone, anhydrous alcohol and deionized water for 10 minutes, then blow dry with a nitrogen gun, and then flatten it with a clean glass plate for use ;

(2) Place the flattened low-profile flexible copper foil on the rotating workpiece holder in the vacuum sputtering chamber, and close the vacuum sputtering chamber. Turn on the vacuum pumping system, when the vacuum degree of the vacuum sputtering chamber reaches 4.0×10 ^-5 Torsla, introduce argon gas, the gas flow rate is 25 sccm, start the ionization power supply, ionize and clean the substrate surface for 10 minutes, and immediately turn on the nickel Chromium alloy target sputtering power supply, sputtering for 4 minutes to form a deposited nickel-chromium film deposited on the substrate. The target current of the nickel-chromium alloy target is set to 3 amps, the bias voltage applied to the substrate is 90 volts, the substrate temperature is room temperature, and the rotating speed of the rotating workpiece holder is set to 4 revolutions per minute;

(3) After the sputtering is completed and cooled by circulating water, the nickel-chromium film deposited on the substrate is taken out from the vacuum sputtering chamber. Put the nickel-chromium-carbon-tungsten thin film deposited on the substrate into RTP-500 type rapid heat treatment equipment for annealing treatment, the annealing conditions are: under the protection of nitrogen, anneal at 300 ° C for 540 seconds, the obtained annealed Nickel-chromium thin film resistor material. Wherein, the thickness of the nickel-chromium thin film is 92.6 nanometers. The elements of the nickel-chromium thin film include nickel 77.3 at.% and chromium 22.7 at.% in atomic percentage.

After etching the nickel-chromium-carbon-tungsten thin films and nickel-chromium thin films of Examples 1 to 4 and Comparative Examples 1 to 2 to form buried resistance devices, they were rapidly heated to 250° C. with HFSE-PB4 type detection probe stations, and then Then gradually and uniformly cool down to 10°C, use Keithley2410 digital source meter to measure its resistance value during the cooling process, according to the formula Calculate the temperature coefficient of resistance of the buried resistance, and make the relationship curve of the temperature coefficient of resistance of Example 1 and Comparative Example 1 with respect to temperature (Figure 2), and the relationship curve of the temperature coefficient of resistance of Example 2 and Comparative Example 2 with respect to temperature (Figure 2 3), the relationship curve of the temperature coefficient of resistance of Example 3 and Comparative Example 1 with respect to temperature ( FIG. 4 ), the relationship curve of the temperature coefficient of resistance of Example 4 and Comparative Example 2 with respect to temperature ( FIG. 5 ).

As can be seen from Figure 2, the temperature coefficient of resistance temperature curve of the deposited NiCrCW film (Example 1) is more stable than that of the deposited NiCr film (Comparative Example 1). 3.39≤|TCR _NiCrCW |≤219.62ppm/K, 165.72≤TCR _NiCr ≤378.97ppm/K, indicating that the electrical properties of the deposited NiCrCW film are more stable than the corresponding NiCr film.

It can be seen from Figure 3 that the temperature coefficient of resistance temperature variation curve of NiCrCW film annealed at 300 ℃ is more stable than that of NiCr film annealed under the same conditions. The variation ranges of the temperature coefficient of resistance of the two are 2.86≤TCR _NiCrCW ≤199.97ppm/K, 35.26≤TCR _NiCr ≤327.31ppm/K, indicating that the NiCrCW film after annealing at 300°C is more stable than the NiCr film after annealing under the same conditions.

It can be seen from Fig. 4 that the temperature coefficient of resistance temperature curve of the as-deposited NiCrCW film (Example 3) is more stable than that of the deposited NiCr film (Comparative Example 1), and the variation range of the temperature coefficient of resistance of the two is 5.69≤|TCR _NiCrCW ≤101.15ppm/K, 165.72≤TCR _NiCr ≤378.97ppm/K, indicating that the deposited NiCrCW film has more stable electrical properties than the deposited NiCr film.

It can be seen from Figure 5 that the temperature coefficient of resistance temperature variation curve of the NiCrCW film annealed at 300°C (Example 4) is more stable than that of the NiCr film annealed under the same conditions (Example 2). The variation ranges of the temperature coefficient of resistance of the two are 3.87≤TCR _NiCrCW ≤98.15ppm/K, 35.26≤TCR _NiCr ≤327.31ppm/K, indicating that the electrical properties of NiCrCW films annealed at 300°C are more stable than those of NiCr films annealed under the same conditions.

From the above four sets of data, it is shown that doping an appropriate amount of C and W elements in the NiCr buried resistance material can help reduce the temperature coefficient of resistance of the buried thin film resistance material, and promote the improvement of the electrical properties of the buried thin film resistance material. effect.

After measuring, the square resistance value of the nickel-chromium-tungsten thin film of embodiment 1 is 76.95Ω/Sq, the square resistance value of the nickel-chromium-tungsten thin film of embodiment 2 is 59.87Ω/Sq, and the square resistance value of the nickel-chromium-tungsten thin film of embodiment 3 The value is 85.26Ω/Sq, the square resistance value of the nickel-chromium-tungsten film in Example 4 is 73.48Ω/Sq, the square resistance value of Comparative Example 1 is 62.84Ω/Sq and the square resistance value of Comparative Example 2 is 50.05Ω/Sq. These data show that doping an appropriate amount of C and W elements in the NiCr buried resistance material can increase the square resistance of the buried resistance material.

_H2SO4 with a mass percent concentration of 60 _% was used as the corrosion solution, the platinum sheet was used as the auxiliary electrode, and the standard saturated calomel was used as the reference electrode. At room temperature, the electrochemical workstation tested Example 1, Example 2, and Comparative Example 1. 1. The passivation anode polarization curve of the embedded thin film resistance material of Comparative Example 2, the test results are shown in Fig. 6 and Fig. 7 .

In FIG. 6 , NiCr corresponds to the deposited NiCr film of Comparative Example 1, and NiCrCW corresponds to the deposited NiCrCW film of Example 1. In FIG. 7 , NiCr corresponds to the annealed NiCr film of Comparative Example 2, and NiCrCW corresponds to the annealed NiCrCW film of Example 2.

It can be seen from Figure 6 and Figure 7 that the corrosion current of the NiCrCW film is smaller than that of the NiCr film no matter in the deposited state or after annealing, and the overpassivation potential of the NiCrCW film is to the right. These phenomena all indicate that the NiCr film is doped with C element and W elements are beneficial to improve the corrosion resistance of the film. Because C mainly exists in the mixed structure of amorphous and nanocrystalline in the film, their mixed interface can promote the diffusion of Cr element in the alloy, so that it is easier for Cr to form a dense Cr ₂ O ₃ protective film on the surface. The chemical properties of W are very stable. Even under the condition of heating, it will not interact with hydrochloric acid and sulfuric acid, and it will not even dissolve in aqua regia. Only the highly corrosive mixture of hydrofluoric acid and nitric acid can dissolve tungsten. This shows that the corrosion resistance of the embedded thin-film resistors of Example 1 and Example 2 is higher than that of Comparative Example 1 and Comparative Example 2, respectively.

Using _H2SO4 with a mass percentage concentration of 60% as the corrosion solution, the embedded thin film resistance materials of Example ₁ and Comparative Example 1 were soaked in the corrosion solution for 85 hours, and then observed with a scanning electron microscope, as shown in Figure 8 and Figure 9 shows. Comparing Figures 8 and 9, it can be seen that the NiCrCW film is obviously smaller in terms of the corroded area, indicating that the corrosion resistance of the NiCrCW film is stronger than that of the NiCr film.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (7)

1. an embed type film resistor material, is characterized in that, comprises nickel chromium triangle carbon W film, and the element of described nickel chromium triangle carbon W film presses atomic percentage, by following elementary composition: nickel 50 ~ 76%, chromium 10 ~ 18%, carbon 10 ~ 30% and tungsten 0.5 ~ 5%.

2. embed type film resistor material according to claim 1, is characterized in that, also comprise substrate, and described nickel chromium triangle carbon W film is deposited on described substrate.

3. embed type film resistor material according to claim 2, is characterized in that, described substrate is low profile flexible copper clad.

4. embed type film resistor material according to claim 1, is characterized in that, the thickness of described nickel chromium triangle carbon W film is 85 nanometer ~ 200 nanometers.

5. a preparation method for embed type film resistor material, comprises the steps:

Substrate is provided; And

Sputtering method is adopted to form nickel chromium triangle carbon W film over the substrate, obtain embed type film resistor material, wherein, the element of described nickel chromium triangle carbon W film presses atomic percentage, by following elementary composition: nickel 50 ~ 76%, chromium 10 ~ 18%, carbon 10 ~ 30% and tungsten 0.5 ~ 5%;

After described employing sputtering method forms the step of nickel chromium triangle carbon W film over the substrate, also comprise the step of described nickel chromium triangle carbon W film being carried out high temperature annealing;

The step of described high temperature annealing is in shielding gas atmosphere, anneals 480 seconds ~ 720 seconds at 250 DEG C ~ 400 DEG C;

The step that described employing sputtering method forms nickel chromium triangle carbon W film over the substrate adopts nichrome target, carbon target and tungsten target material, nickel chromium triangle, carbon and tungsten is sputtered onto on described substrate, deposits nickel chromium triangle carbon W film over the substrate;

Described employing sputtering method is formed in the step of nickel chromium triangle carbon W film over the substrate, and the electric current of described nichrome target is 2 ~ 5 peaces, and the electric current of described carbon target is that 1 peace ~ 1.5 are pacified, and the electric current of described tungsten target material is that 0.1 peace ~ 0.3 is pacified.

6. the preparation method of embed type film resistor material according to claim 5, is characterized in that, described employing sputtering method is formed in the step of nickel chromium triangle carbon W film over the substrate, applies the bias voltage of 30 volts ~ 120 volts over the substrate.

7. the preparation method of embed type film resistor material according to claim 5, is characterized in that, described employing sputtering method is formed in the step of nickel chromium triangle carbon W film over the substrate, and described substrate rotates, and the speed of described rotation is 4 revs/min.