KR101886963B1 - Method for controlling resistivity of nickel based metal foil - Google Patents

Abstract

The present invention relates to a method for controlling resistivity of nickel-based metal foil, which comprises a step of forming a nickel/tin alloy layer on a surface of nickel-based metal foil by depositing tin on the nickel-based metal foil through chemical vapor deposition using a tin precursor on the nickel-based metal foil.

Description

[0001] METHOD FOR CONTROLLING RESISTENCE OF NICKEL BASED METAL FOIL [0002]

The present invention relates to a method of controlling the resistivity of a nickel-based metal foil, and more particularly, to a method of adjusting the resistivity of a nickel-based metal foil to an arbitrary target value.

Resistivity is a measure of how strongly a material confronts the flow of current, the reciprocal of the conductivity, and also called the resistivity. A low resistivity means that the material is less likely to interfere with the movement of the charge. The SI unit of resistivity is ohmmeter (Ωm). Unlike electrical resistance, the same material is an intensive property with the same value regardless of the size of the object.

Metallurgy is a technique for extracting metals from ores, smelting them, adjusting the composition and organization to suit the purpose of use, and conventionally, there is metallurgy as a technique for controlling the resistivity of metals . Metallurgy can be divided into metal smelting, which extracts and smelts metals from ore, and metal materials, which make metals and alloys suitable for various purposes. To change the electrical and physical properties of metals, new alloys must be made using methods in the field of metal materials. To make alloys, several metals must be melted and processed. However, since the melting point of metal is very high, the process time and process cost consumed for alloy manufacture are very large. Therefore, there is a need for a new technique capable of controlling the resistivity of the metal while reducing the process cost and the process time, compared with the prior art.

Recently, electronic devices are equipped with various functions and high performance, and accordingly, the amount of power required has also increased. In addition, the use of high-power devices has increased in many fields such as solar cells, wind power generation, transportation, and the like. These high power devices use power due to overloading for high power usage, so there is a high risk of power loss due to overload and damage to electronic equipment. Therefore, it is required to develop protective devices for high current to protect electronic devices and circuits. A typical protection element, a fuse-type resistor, operates as a resistor in a steady state and is fused when the overcurrent flows and functions as a fuse. Until now, metals such as Sn, Sn / Zn and Sn / Pb have been used for the fuse type resistor. However, these metals have a low resistivity and a melting point of about 20 μΩcm and 200 ° C., respectively. Therefore, they can not be used in high current fused resistors. Nickel-based alloys can be used in fuse-type high-current resistors because they have high permissible current due to their high melting point. However, in order to realize various functions, a fuse-type resistor having a high resistivity of various resistances is required to be applied to a complicated electronic circuit, and a technique for controlling the resistivity of a metal material is required to fabricate the fuse resistor.

It is an object of the present invention to provide a method for controlling the resistivity of a nickel-based metal foil.

A method for controlling the resistivity of a nickel-based metal foil for an object of the present invention includes depositing tin on the nickel-based metal foil by chemical vapor deposition using a tin precursor on the nickel-based metal foil, And forming a nickel / tin alloy layer.

In one embodiment, the chemical vapor deposition process can be performed at a pressure of 10 Torr or less.

In one embodiment, the chemical vapor deposition of the tin may be performed at a temperature of from 250 캜 to 950 캜.

In one embodiment, the tin precursor is selected from the group consisting of dibutyltin diacetate (C ₁₂ H ₂₄ O ₄ Sn, DBTDA), tetrametyl tin (C ₄ H ₁₂ Sn), tetrabutyl tin (C ₁₆ H ₃₆ Sn), tin chloride (SnCl ₄ ), and tin alkoxide.

In one embodiment, in the step of forming the nickel / tin alloy layer, a tin layer may be formed on the nickel / tin alloy layer.

According to the present invention, a tin precursor is deposited on the nickel-based metal foil by a chemical vapor deposition method on a nickel-based metal foil to form a nickel / tin alloy layer on the surface of the nickel-based metal foil, The resistivity of the nickel-based metal foil can be controlled. The nickel / tin alloy is formed on the nickel-based metal foil having a high melting point, so that the resistivity of the nickel surface can be controlled, so that a high-current fuse-type resistor can be applied to a complicated electronic circuit that implements various functions.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an apparatus for implementing an embodiment of the present invention.
FIG. 2 is a diagram showing a change with the process temperature. FIG.
3 is a view showing a change with the process temperature.
4 is a view showing a change with the process temperature.
5 is a view of a nickel / tin alloy layer.
6 is a view showing an alloy layer deposition rate according to a process temperature.
7 is a view showing tin content according to the process temperature.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the term "comprises" or "having ", etc. is intended to specify that there is a feature, step, operation, element, part or combination thereof described in the specification, , &Quot; an ", " an ", " an "

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

A method of controlling the resistivity of a nickel-based metal foil according to an embodiment of the present invention includes depositing tin on the nickel-based metal foil by a chemical vapor deposition method using a tin precursor on the nickel-based metal foil, And forming a nickel / tin alloy layer.

The nickel-based metal is not particularly limited. For example, as the nickel-based metal, a nickel-containing alloy such as Ni / Fe, Ni / Cu or Ni / Cr may be used, or pure nickel may be used. In one embodiment, the nickel-based metal foil may be a nickel foil.

The tin precursor is not particularly limited, and in one embodiment of the present invention, the tin precursor is dibutyltin diacetate (C ₁₂ H ₂₄ O ₄ Sn, DBTDA), tetrametyl tin (C ₄ H ₂ Sn), tetrabutyl tin (C ₁₆ H ₃₆ Sn), tin chloride (SnCl ₄ ), and tin alkoxide. . The tin precursor may be in a gaseous state or in a liquid state, and the tin precursor in a liquid state may be used in a gaseous state.

The chemical vapor deposition method of the present invention is not particularly limited, but may be performed using the chemical vapor deposition apparatus shown in FIG. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an apparatus for implementing an embodiment of the present invention. As shown in FIG. 1, an inert gas (for example, an inert gas such as argon) whose flow is controlled by a liquid tin precursor and a mass flow controller (MFC) is injected into a bubbler to form a liquid tin precursor To the gaseous state. The gaseous tin precursor is introduced through a tube into a high temperature furnace. In the high temperature furnace, tin is deposited on a nickel-based metal foil, and a nickel / tin alloy layer is formed on the surface of the nickel-based metal foil. At this time, the flow rate of the tin precursor in the gaseous state can be controlled by a valve and a pump.

The chemical vapor deposition method may be performed at a pressure lower than atmospheric pressure (760 torr) and may be performed at a pressure of 10 Torr or lower. For example at a pressure of 4 Torr. In the case of using a nickel foil with a nickel-based metal foil, since the melting point of the nickel foil is as high as 1455 DEG C, it is difficult to react with tin to form a nickel / tin thin film. To solve this difficulty, a low-pressure chemical vapor deposition apparatus can lower the process pressure and react the tin precursor with the nickel-based metal foil at a temperature lower than the melting point of the nickel foil.

In one embodiment, the step of forming the alloy layer may be performed for 10 minutes or more and may be performed for 1 hour or more, for example.

In one embodiment of the present invention, the chemical vapor deposition of the tin may be performed at a temperature of 250 ° C to 950 ° C, and may be performed at a temperature of 300 ° C to 900 ° C, for example.

The nickel / tin alloy layer is not particularly limited and represents an alloy layer containing nickel and tin. For example, Ni ₃ Sn and may be Ni ₃ Sn ₂ .

In one embodiment of the present invention, in the step of forming the nickel / tin alloy layer, a tin layer may be formed on the nickel / tin alloy layer. The tin layer may be a tin layer formed of tin deposited on a nickel-based metal foil via chemical vapor deposition using a tin precursor and may not contain nickel.

In addition, the depth of the alloy layer from the surface of the alloy layer may decrease as the depth of the alloy layer increases. As the temperature of the step of forming the alloy layer increases, the nickel / tin alloy crystal size of the alloy layer may increase.

FIGS. 2 to 4 are diagrams showing changes with process temperatures. FIG. Specifically, FIG. 2 is a graph showing a change in specific resistance of a nickel foil according to a temperature, and FIG. 3 is an image obtained by observing a surface of a nickel foil with a scanning electron microscope. In this case, nickel foil was used as the nickel metal foil and DETDA was used as the tin precursor. The temperature was 300 to 900 DEG C, the flow rate of the DETDA used as the tin precursor was 25 sccm, the process pressure was 4 Torr, and the process time was 1 hour .

Referring to the graph shown in FIG. 2, it can be seen that the resistivity value measured when the temperature of the nickel foil was 400 ° C was 28.9% greater than the specific resistance bare of the nickel foil before the process. In addition, the increase in the resistivity increases with increasing temperature, but the resistivity increases continuously, which is 42.2% higher than the original resistivity at 900 ℃.

Referring to FIG. 3, as the temperature of the process increases, the grain size of the nickel / tin alloy formed on the surface increases. In particular, when the temperature is 800 ° C or higher, the shape of the nickel / tin alloy layer crystal is clearly observed over the entire surface of the nickel foil.

FIG. 4 is a graph showing an X-ray diffraction spectroscopy (XRD) spectrum showing a change in crystallinity of a nickel foil according to a temperature. Referring to FIG. 4, as the temperature of the nickel foil increases, the peaks of Ni ₃ Sn and Ni ₃ Sn ₂ , which are nickel / tin alloys, become larger and more pronounced.

2 through 4, it can be seen that as the temperature increases, the nickel / tin alloy is well formed on the nickel foil surface and the resistivity increases.

In an embodiment of the present invention, in the step of forming the nickel / tin alloy layer, the resistivity of the nickel-based metal foil may be increased as the content of tin is increased. Therefore, the specific resistance of the nickel-based metal foil can be controlled by controlling the content of the tin.

In one embodiment, in the step of forming the nickel / tin alloy layer, the resistivity of the nickel-based metal foil can be increased as the deposition rate of the tin is increased. Accordingly, the resistivity of the nickel-based metal foil can be controlled by controlling the deposition rate of the tin.

5 is a view of a nickel / tin alloy layer. 5 is a graph showing the amount of tin detected according to the depth of the nickel / tin alloy layer. Analysis was performed to determine whether the change in resistivity identified in FIGS. 2 to 4 was due to the nickel / tin alloy layer or tin atom diffusion. The graph of FIG. 5 was analyzed by secondary ion mass spectroscopy (SIMS). In order to confirm the diffusion of tin atoms, the process time was adjusted to 12 minutes and the thickness of the nickel / tin alloy layer was adjusted to 200 nm Respectively. Referring to FIG. 5, as the depth of the nickel / tin alloy layer became deeper, the amount of tin detected decreased, and little was detected after 160 nm. Therefore, it can be confirmed that the cause of the change in the resistivity of the nickel foil is not the diffusion of tin atoms into the sample but the nickel / tin alloy layer formed on the surface of the sample.

6 is a view showing an alloy layer deposition rate according to a process temperature. Referring to FIG. 6, as the temperature of the process increases, the deposition rate of the nickel / tin alloy layer increases, and the increase in the vicinity of 420 ° C. decreases. In addition, although the increase is similar to the aspect of the graph of the deposition rate graph of the nickel / tin alloy layer according to the temperature of FIG. 6 and the graph of the change of the specific resistance with respect to the temperature of FIG. 2, it shows a continuously increasing pattern.

7 is a view showing tin content according to the process temperature. Referring to FIG. 7, when the process temperature is 400 ° C., the tin content of the nickel foil increases by about 13%. However, the increase range decreases in the range of 400 ° C. to 900 ° C., The tin content is about 16%.

In the graph of change in resistivity, nickel / tin alloy layer deposition rate, and tin content with temperature, all of the three graphs showed a similar pattern in which the increase was decreased but the value increased continuously. As the tin content, tin deposition rate and process temperature increase, the resistivity of the nickel-based metal foil increases. Thus, the resistivity change can be predicted through the content of tin, the rate of deposition of tin, and the temperature of the process, and the resistivity of the nickel-based metal foil can be controlled by controlling the content of tin, the rate of deposition of tin, and the temperature of the process.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims. It can be understood that it is possible.

Claims (5)

Depositing tin on the nickel-based metal foil by chemical vapor deposition using a tin precursor on the nickel-based metal foil to form a nickel / tin alloy layer on the surface of the nickel-based metal foil.
A method for controlling the resistivity of a nickel - based metal foil.
The method according to claim 1,
Wherein the chemical vapor deposition process is performed at a pressure of 10 Torr or less.
A method for controlling the resistivity of a nickel - based metal foil.
The method according to claim 1,
Characterized in that the chemical vapor deposition of the tin is carried out at a temperature of from < RTI ID = 0.0 > 250 C < / RTI &
A method for controlling the resistivity of a nickel - based metal foil.
The method according to claim 1,
The tin precursor may be selected from the group consisting of dibutyltin diacetate (C ₁₂ H ₂₄ O ₄ Sn, DBTDA), tetrametyl tin (C ₄ H ₁₂ Sn), tetrabutyl tin (C ₁₆ H ₃₆ Sn), tin chloride (SnCl ₄ ), and tin alkoxide. The method of claim 1,
A method for controlling the resistivity of a nickel - based metal foil.
The method according to claim 1,
Characterized in that in the step of forming the nickel / tin alloy layer, a tin layer is formed on top of the nickel / tin alloy layer.
A method for controlling the resistivity of a nickel - based metal foil.

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