KR20160125922A - Bonding material with amorphous characteristics and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a bonding material with amorphous characteristics and a manufacturing method thereof, comprising the following steps: preparing a water-based alloy electrolysis solution containing two or more metal salts including a first and a second metal salt; immersing electrodes in the water-based alloy electrolysis solution to form an electrolysis circuit; applying, to a control unit for controlling the electrolysis circuit, a reduction potential to the electrodes according to a reduction potential value of the metal salts to be plated; and forming an amorphous metal plate film including a first and a second metal, and alloy of the first and the second metal. A step of applying the reduction potential applies a square pulse voltage including a first application section to apply a first voltage (V_1) and a second application section to apply a second voltage (V_2). The first voltage (V_1) is higher than the second voltage (V_2), and the first and the second voltage (V_1, V_2) are 0 to -4.5 V. According to the present invention, potential (voltage) is alternatingly applied through a power source capable of applying the potential in a state of immersing a mother material in a plating bath including two or more metal salts, a complex multilayer can be easily formed in a short time through inexpensive equipment. A time and a current density of each potential cycle are adjusted, so a plating thickness of each layer can be adjusted. Moreover, the number of complex layers can be easily adjusted by the number of potential cycles.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding material having amorphous properties and a method of manufacturing the same,

The present invention relates to a bonded material having amorphous properties and a method of manufacturing the same. More particularly, the present invention relates to a bonding material having amorphous characteristics, and more particularly, A method of manufacturing a bonded material, and a method of bonding a bonded material at a lower temperature than a conventional brazing and soldering temperature using such a bonded material.

Techniques related to the method of forming a multilayer thin film layer have been proposed in Patent Registration No. 0560296 and Patent Registration No. 0932694. [

Hereinafter, a method of manufacturing a multilayer metal thin film and a multilayer thin film coating apparatus and method disclosed in the patent registration Nos. 0560296 and 0932694 are described briefly.

1 is a view showing a method of manufacturing a multilayer metal thin film in Patent Registration No. 0560296 (hereinafter referred to as "Prior Art 1"). As shown in FIG. 1, in the method of manufacturing a multilayered metal thin film of the prior art 1, in the method of manufacturing a thin metal film, titanium films 22 and 25 oriented in the <002> direction by ionized physical vapor deposition To about 149 A thick; Depositing titanium nitride films (23, 26) oriented in the <111> direction on the titanium films (22, 25); And depositing an aluminum film 24 oriented in the <111> direction on the laminated film of the titanium / titanium nitride films 22, 23, 25 and 26.

However, since the method of manufacturing the multilayered metal thin film according to the prior art 1 is deposited by using physical vapor deposition (PVD), metal organic chemical vapor deposition (MOCVD), or IPVD, But it had to be implemented through a machine.

A method for depositing a metal layer on a substrate of Patent Registration No. 0932694 (hereinafter, referred to as 'Prior Art 2') includes: a pretreatment step of performing plasma cleaning or ion beam cleaning on the surface of the product; A first thin film layer forming step of forming a first thin film layer by performing one of evaporation deposition, sputtering and reactive sputtering on the surface of the pretreated product; A second thin film layer forming step of forming a second thin film layer on the surface of the first thin film layer by performing one of sputtering, reactive sputtering, plasma penetration, and ion beam penetration; And repeating the first thin film layer forming step and the second thin film layer forming step.

However, the method of depositing the metal layer on the substrate according to the prior art 2 also has disadvantages in that the multilayer thin film is formed by vapor deposition, so that the cost is increased and the vapor deposition machine is expensive.

In addition, in the case of a PVD process including sputtering, a vacuum apparatus is necessary because a vacuum process is performed, and a chemical thin film forming process including a CVD process must also be carried out in a vacuum, and since the process temperature is high, You can give. In the case of the ALD method, the source material is limited and the growth rate of the layer is slow. Printing methods including the roll printing method are difficult to control the thickness of the layer and take a long time to form a multilayer.

Korean Patent No. 10-0560296 (Mar. 2006) Korean Patent No. 10-0932694 (December 10, 2009)

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a multilayered metal plating film which is produced by laminating at least two metals with a metal plating layer through electrolytic plating, A joining member capable of joining is provided.

The present invention also provides a method of manufacturing the multilayered metallic plating film, wherein a base material is immersed in a plating bath containing two or more metal salts and a potential (voltage) is applied thereto through a power source to manufacture the multilayered metallic plating film in a safe and short time A method for manufacturing a bonded material is provided.

The present invention also provides a low-temperature bonding method of a material to be bonded such as an electric or electronic part using the bonding material as a bonding medium.

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

The present invention provides a method for preparing a water-based alloy plating solution comprising: preparing an aqueous alloy plating solution containing at least two metal salts including a first metal salt and a second metal salt; Immersing the electrode in the aqueous alloy plating solution to form an electrolytic plating circuit; Applying a reduction potential to the electrode according to a reduction potential value of the metal salt to be plated to a control unit for controlling the electrolytic plating circuit; And forming an amorphous metal plating film including the first metal, the second metal, and an alloy of the first metal and the second metal, the method comprising the steps of: Wherein the first voltage V ₁ is applied to the first voltage V ₁ and the second voltage V ₂ is applied to the first voltage V ₁ , the second is higher than the second voltage (V _2), and the first voltage (V ₁₎ and said second voltage (V ₂₎ is provided a method of manufacturing a voltage of -4.5V on the joining material between 0V.

And the range of the reduction potential value of the metal salts is + 1.83V to -1.67V.

The water based alloy plating solution further comprises a first metal salt, a second metal salt, an acid, and an additive in a plating solution based on water.

And the concentration ratio of the first metal salt and the second metal salt in the plating solution is in the range of 2: 1 to 100: 1.

The first and second metal salts may be different metal salts and may be Sn, Cu, Zn, Ni, Al, Ti, V, Cr, Mn, Fe, Co, Ga, Ge, As, Zr, Nb, And at least one metal salt selected from the group consisting of Pd, Ag, Cd, In, Sb, Te, Hf, Ta, W, Re, Os, Ir, Pt, Au, Tl, Pb and Bi. &Lt; / RTI &gt;

The first and second metal salts may be selected from two or more metal salts of a metal having a standard reduction potential difference of 0.029 V or more and 1.0496 V or less.

The acid may be selected from among sulfuric acid, hydrochloric acid, methanesulfonic acid (MSA), nitric acid, boric acid, acetic acid, organic sulfuric acid, citric acid, formic acid, ascorbic acid, hydrofluoric acid, phosphoric acid, lactic acid, amino acid, hypochlorous acid Of the present invention.

Further, the additive is selected from polyoxyethylene lauryl ether (POELE), a plating flatting agent (smoothing agent), an accelerator, an inhibitor, a defoamer, a polishing agent and an oxidation inhibitor.

The forming of the amorphous metal plating layer may include forming at least two layers, forming a first plating layer in the first application period and forming a second plating layer in the second application period &Lt; / RTI &gt;

Also, when the amorphous metal plating film is laminated with two layers including a first plating layer and a second plating layer, the first time t ₁ is set to 0 <t ₁ ≤ 10 (min), the second time t ₂ ) is set to 0 < t ₂ &amp;le; 200 (min), and thicknesses of the first plating layer and the second plating layer are respectively set in the range of 10 nm to 150 nm.

And the amorphous metal plating film has a total thickness ranging from 0.6 nm to 300 mu m.

The present invention also provides a bonding material comprising at least two metals having a difference in standard reduction potential of not less than 0.029 V and not more than 1.0496 V and comprising at least two amorphous metal plating films, , The amorphous metal plating film undergoes an exothermic reaction during the initial melting, and the temperature (T _m1 ) at which the amorphous metal plating film is first melted provides a bonding material having a temperature lower than the temperature (T _m2 ) at which it is melted after the solidification.

Further, the amorphous metal plating film includes a first plating layer and a second plating layer, and each of the plating layers has a thickness of 10 nm to 150 nm.

The metal may be selected from the group consisting of Sn, Cu, Zn, Ni, Al, Ti, V, Cr, Mn, Fe, Co, Ga, Ge, As, Zr, Nb, Mo, Ru, Rh, Pd, Ag, And at least one metal selected from the group consisting of Sb, Te, Hf, Ta, W, Re, Os, Ir, Pt, Au, Tl, Pb and Bi.

The total thickness of the amorphous metal plating film is 0.6 to 300 탆.

Also, the amorphous metal plating film provides a bonding material having a structure in which the first plating layer and the second plating layer are repeatedly laminated six or more times.

Also, the amorphous metal plating film provides a bonding material whose melting temperature (T _m1 ) at the initial melting is lower than the melting point (T _ma ) of the total bulk composition constituting the amorphous metal plating film.

Also, the bonding material is a material for low-temperature bonding in which the amorphous metal plating film bonds the materials to be bonded by an exothermic reaction caused by a change in crystal phase from amorphous to crystalline.

According to the present invention, in producing a bonded material, a potential (voltage) is alternately applied through a power source in a state in which a base material is immersed in a plating bath containing two or more metal salts to easily form a multilayer through a low-cost equipment in a short time The plating thickness of each plating layer can be controlled so that the exothermic reaction due to the change from amorphous to crystalline can be controlled by controlling the voltage, current density or time of each potential cycle. The number of potential layers can be easily controlled by the number of potential cycles There is an effect that can be.

Further, when bonding the material to be bonded using the bonding material according to the present invention to the bonding material at a low temperature, it is possible to bond the surface of the material to be bonded by using a flux in a vacuum state, an inert gas, a reducing gas atmosphere, , Plated film materials can be used as a bonding medium by plating all metals such as common metals (eg, copper, tin, zinc, nickel) as well as precious metals. The laminated individual metal plating layer made of dissimilar metals has amorphous properties in the junction medium produced to the nanometer scale level. The amorphous phase is unstable and an exothermic reaction occurs during the phase change to the crystalline phase. In addition, when the thickness of the laminated metal plating layer is formed at the nanometer level, the surface area between the plating layers becomes wider and becomes more unstable and melts by the exothermic reaction at a temperature lower than the melting point of the conventional bulk material.

In order to produce nano-metal powder, expensive noble metal powders, such as gold and silver, which are easily oxidized and easily oxidized due to their large contact area with oxygen in the atmosphere, are used . On the other hand, the cost of the bonding medium, which is a bonding material produced by the present invention, is much lower than that of the nano powder.

In addition, unlike nano powders which are likely to be oxidized during manufacturing, since the bonding material of the bonding material prepared according to the present invention is plated with a layer other than a noble metal in a room-temperature plating bath in an atmospheric environment, Natural oxide film only).

In addition, unlike the conventional nano powder having a risk of explosion or fire due to rapid oxidation and heat generation of the nano powder, the multilayered plating film is easy to handle and has a safe effect.

The present invention is also advantageous in that it can be easily mass produced using a plating method unlike a method in which a multilayer is formed by physical vapor deposition (PVD) or chemical vapor deposition (CVD) such as sputtering in vacuum have.

Further, in the present invention, if a roll-shaped plating electrode is used, the joining material can be peeled off and can be produced as independent independent foil-type joining material, and the production efficiency of the thin plate is increased.

Further, the present invention has an effect that the thickness of the bonding material can be controlled so that an exothermic reaction can be arbitrarily performed by changing the amorphous to crystalline state by controlling the composition of the plating liquid, the pulse and the plating time.

In addition, in the present invention, a bonded material manufactured to have a heat generation characteristic by changing from an amorphous to a crystalline state can significantly lower a bonding temperature compared to a conventional bulk type bonding medium, have. For example, the bulk material of the Sn-Ag based brazing material, which is widely used for bonding copper in the electronics industry, has a lowest melting point (eutectic temperature) of about 221 DEG C, and the Sn-3.5 wt% At 250 캜, copper to be bonded is bonded. On the other hand, the Sn-Ag based multilayer plating films alternately stacked with Sn and Ag prepared according to the present invention have a lower melting point and can be used at a temperature of about 160 ° C lower than the bulk material or at a lower temperature Copper to be bonded can be bonded.

In addition, in the conventional method, a noble metal powder having a nanometer-scale size is generally used as a kind of noble metal powder, and the melting point of the noble metal powder is lowered to perform low-temperature bonding. In the present invention, different kinds of plating layers are alternately layered at a nanometer- There is an effect that can be. If different types of metal layers are used as the bonding medium, the two metal layers are spread and melted to form an alloy, so that the strength of the joints is more improved than that of one kind of metal.

In addition, the bonding material produced by the present invention showed a peak in a temperature range of not less than 52.3% (Ni-Cu multilayer thin film) and 87.1% (Cu-Ag multilayer thin film) of the bulk of the conventional bonding medium alloy melting point And bonding (brazing, soldering) is possible by using the bonding material according to the present invention even in this temperature range in which the conventional bulk type bonding medium is not melted. Also, the bonding temperature at this time can be bonded even below the melting point of the entire bulk composition constituting the plating layer, and as one embodiment of the bonding temperature (Example 4), the first plating layer and the second plating layer of the Ni- And they were bonded at 600 ° C to 1000 ° C, which is the lowest melting point of 1083 ° C or less.

Of course, when the medium of the present invention is used, the upper limit of the junction temperature is effective to the melting point of the existing bonding medium or the melting point of the material to be bonded, which is higher than 87.1%.

In addition, the bonding material produced by alternately laminating different types of plating layers in the form of layers and having a thinned individual metal layer formed by electrolytic plating or electroless plating exhibits amorphous characteristics and becomes unstable due to an increase in the surface area between the respective plating layers, Each of the plated layers constituting the bonding material has an exothermic reaction easily when it is heated at a low temperature. In this case, melting is performed at a temperature lower than the melting point of the conventional bulk material, and this melting phenomenon has no relation with the stacking order of the respective plating layers constituting the bonding material.

This can be used to bond the bonded materials at low temperatures. Therefore, low-temperature soldering or low-temperature brazing is enabled.

1 is a schematic view showing a method of manufacturing a multilayered metal thin film according to the prior art 1;
2 is a block diagram showing a method of manufacturing a bonded material according to the present invention.
3 is a schematic view of a bonding material manufacturing apparatus for implementing the bonding material manufacturing method of the present invention.
4 is a cross-sectional view showing a bonded material produced by the method of manufacturing a bonded material of the present invention.
5 is a block diagram showing a reduced potential measurement method for implementing the method of manufacturing a bonded material of the present invention.
6 is a photograph photograph of a current, a potential and a plating power source apparatus in which the metal of the first section is plated.
7 is a photograph of a current, a potential, a repetition rate, and a recording power of the plating power source in which the metal of the second section is plated.
8 is a graph showing the formation of a bonding material according to a content ratio of a metal salt and a reduction potential difference in a plating solution according to the present invention.
FIGS. 9A to 9H are cross-sectional photographs of a bonding material in which the types of the first metal salt, the second metal salt, and the reduction potential are different in the plating solution according to the present invention.
10 is a graph showing a range of formation of a bonding material according to a content ratio of a metal salt and a reduction potential difference in a plating solution according to the present invention.
11 is a scanning electron microscope (SEM) photograph showing a cross-section of a Sn-Cu multilayer plated film formed by the method for producing a bonded material of the present invention.
12 is a scanning electron microscope (SEM) photograph showing a cross-section of a Sn-Cu multilayered plated film in which individual plated layers stacked by the method for producing a bonded material of the present invention are made thick.
13 is a scanning electron microscope (SEM) photograph showing a cross-section of a Zn-Ni multi-layered plated film formed by the method for producing a bonded material of the present invention.
14 is a cross-sectional view of a bonded material in which a first plating layer, a second plating layer, and a third plating layer are alternately laminated when a third metal salt is added to the metal salt according to the present invention.
FIG. 15 is a graph showing a condition under which a metal is oxidized and reduced to explain a method of bonding at a low temperature using a bonding material of the present invention.
16 is a graph showing the thermal characteristics of the Ni-Cu bonded material produced by the present invention measured by DTA (Differential Thermal Analysis).
FIG. 17 is a photograph showing low temperature bonding of 304 stainless steel for 10 minutes at 600 ° C, 700 ° C, 800 ° C and 1000 ° C using the Ni-Cu bonding material prepared in the present invention as a bonding medium.
18 is a photograph of a fractured surface obtained by low temperature bonding of 304 stainless steel at 900 DEG C for 10 minutes using the Ni-Cu bonding material prepared in the present invention as a bonding medium.
FIG. 19 is a graph of DSC (Differential scanning calorimetry) measurement of thermal properties of the Sn-Cu bonded material produced in the present invention during heating.
20 is a photograph of the Sn-Cu bonding material produced in the present invention on a copper substrate.
FIG. 21 is a photograph showing low temperature bonding of a copper plate for 10 minutes at 160 ° C., 170 ° C. and 210 ° C. in a vacuum of 10 ^-3 torr using the Sn-Cu bonding material prepared in the present invention as a bonding medium.
22 is a graph showing the thermal characteristics of the Cu-Ag bonded material produced in the present invention when measured by DTA.
FIG. 23 is a photograph (left) of the first and second plating layers (left) as plated before heating of the Sn-Cu bonded material produced in the present invention and a view (right) showing the disappearance of the first and second plating layers by diffusion after heating to be.
Fig. 24 is a photograph (right) of the first and second plating layers (left) in the plated state before heating of the Ni-Cu bonded material produced in the present invention and the first and second plating layers disappearing due to diffusion after heating to be.
FIG. 25 is a graph (blue) showing the amorphous characteristics of the Sn-Cu bonded material produced by the present invention as analyzed by XRD before heating, and a graph (red) showing the crystalline characteristics as a result of XRD analysis after heating.
26 is an electron micrograph (SEM) photograph showing a cross section of a multi-layered metal material produced by thickening the sum of the thicknesses of the two plated layers to 5 μm.
27 is a heating graph in which a multilayer metal material is manufactured such that the sum of the thicknesses of the two plating layers is 5 탆 thick and the thermal characteristics are measured using a differential scanning calorimeter (DSC).
28 is an optical microscope photograph showing an actual cross-section of a joint of a multi-layered metal material prepared by thickening the sum of the thicknesses of the two plated layers to 5 탆 and joining them.
FIG. 29 is an optical microscope photograph showing the copper electrode cross section made by laminating six layers of multilayer film metal materials at a low temperature.
30 is an optical microscope photograph showing an end face portion of a Sn-Cu-based metal plating thin film produced by lengthening the plating time of the multilayer metal material to have a total plating thickness of 300 mu m.

Before describing the present invention in detail, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention, which is defined solely by the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise stated.

Throughout this specification and claims, the word "comprise", "comprises", "comprising" means including a stated article, step or group of articles, and steps, , Step, or group of objects, or a group of steps.

On the contrary, the various embodiments of the present invention can be combined with any other embodiments as long as there is no clear counterpoint. Any feature that is specifically or advantageously indicated as being advantageous may be combined with any other feature or feature that is indicated as being preferred or advantageous. Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.

FIG. 2 is a block diagram showing a method for manufacturing a bonded material according to the present invention, and FIG. 3 is a schematic view of a bonded material manufacturing apparatus for implementing the method for manufacturing a bonded material according to the present invention. And FIG. 5 is a block diagram showing a reduced potential measurement method for implementing the method of manufacturing a bonded material according to the present invention. As shown in FIG.

Referring to these drawings, the method for manufacturing a bonded material using the plating method of the present invention comprises immersing electrodes 12, 13, and 14 in an aqueous alloy plating liquid 15 containing two or more metal salts, The first plating layer 33 and the second plating layer 34 are alternately plated with each other to form a bonded material.

In this specification, the first plating layer is the layer in which the first metal and the second metal are theoretically reduced and plated, but the first plating layer is a layer in which the first metal is mainly plated because the first metal is plated in a minute amount, Means a first metal-rich layer also containing an alloy of one metal and a second metal and a second metal.

The second plating layer is a layer mainly plated with the second metal. Theoretically, the second plating layer is the pure second metal layer. In practice, however, the alloy contains the first metal and the second metal, 2 metal rich layer.

The reason why the first metal, the second metal, and the alloy are included in each of the plating layers is that, even if one electric potential is theoretically a potential for reducing only a specific metal in the case of using one electrolytic bath, , And the remaining metals tend to be plated together.

As a method for implementing this, a method of preparing an electrode and an aqueous alloy plating solution (S100), an electrolytic plating circuit forming step (S110), a reducing potential or a current applying step (S120), a voltage or a corresponding current, And a plating step (S140).

In the present invention, the metal salt in the plating solution is ionized, and in order to deposit on the cathode using electric current, a voltage higher than the reduction potential of each metal element should be applied. In the case of a plating solution having two or more metal salts, there is a difference in standard reduction potential between the two elements, and thus, a voltage range in which the type of the metal to be plated is different varies. When these voltage sections are alternately applied, plating layers having different kinds of metals to be plated are alternately deposited. The voltage section may be represented by a first application period in which the first metal is predominantly plated and a second application period in which the second metal is plated predominantly.

As described above, in the present invention, the alternately deposited plating layers have a laminated structure in which thin films having a wide surface are piled up in a regular order. At this time, if the thickness of the individual metal layer in the multi-layered plating layer becomes thinner to the nanometer scale, the characteristics are significantly different from those of the bulk metal. Specifically, each of the plated layers laminated at a nanometer level has an amorphous characteristic and becomes unstable due to an increase in the surface area between the respective metal layers, and each of the plated layers laminated easily shows an exothermic reaction when it is heated at a low temperature. This allows the alloy to be easily melted to form an alloy even at a temperature lower than the melting point in the bulk material state. Therefore, it is generally possible to perform the bonding process performed at a high temperature at a low temperature.

A bonding material manufacturing apparatus 10 for implementing a bonding material manufacturing method using the plating method according to the present invention comprises a container 11, a reference electrode 12, an anode 13, a cathode 14, a stirring magnet 16 And a PC 20 as a control unit.

The vessel (11) is a plating bath in which an opened top is closed with a stopper (11a) and a stirring magnet (16) is installed on an inner bottom.

As the reference electrode 12, a saturated calomel electrode was used. A 10 mm X 0 mm platinum (Pt) electrode was used as the anode 13 and a 10 mm X 0 mm copper electrode was used as the cathode 14 electrode. Different types of conductive metals can be used for the anode and cathode depending on the plating conditions and the size can be adjusted. The power supply can use both a constant current and a constant voltage.

The stirring magnet 16 is disposed on the bottom surface of the container 11 to stir the plating liquid stored in the container 11 and drive magnet (not shown) is provided on the drive shaft at the lower end of the container 11 (Not shown in the drawing) is driven, the driving magnet is operated by the principle of interlocking the stirring magnet 16 disposed on the bottom surface of the container 11 by the magnetic force.

The PC 20 as the control unit is provided with software such as a power supply capable of adjusting voltage and current waveforms and a waveform adjustment program, and is capable of controlling voltage and current waveforms through input and manipulation. The PC 20 is provided with a positive electrode 17 of a power source to be electrically connected to the positive electrode 13 through a wire and a reference electrode 18 of a power source to be electrically connected to the reference electrode 12 through a wire, And a negative electrode 19 of a power source is provided so as to be electrically connected to the negative electrode 14 through electric wires.

The electrode and aqueous alloy plating solution preparation step (S100) is a step of preparing and manufacturing an electrode and an aqueous alloy plating solution (15), respectively. At this time, the electrode includes a reference electrode 12, an anode 13, and a cathode 14. The plating solution 15 includes the first metal salt and the second metal salt, and may include an acid and an additive.

The first and second metal salts may be at least one selected from the group consisting of Sn, Cu, Zn, Ni, Al, Ti, V, Cr, Mn, Fe, Co, Gallium, Ge, As, Zr, Nb, Mo, (Rh), Pd, Ag, Cd, In, Sb, Tell, Hf, Ta, W, Metals such as rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), thallium (Tl), lead (Pb) and bismuth (Bi) Two or more metal salts of the elements which differ in the reduction potential in the range of 0.029 V to 1.0496 V can be used. The concentration ratio of the first and second metal salts in the plating solution is preferably selected in the range of 2: 1 to 100: 1. In this embodiment, Cu, Sn, Pb, Bi, Ag, Ni, and Zn, which have the highest utilization, are selected and multilayer plating is performed.

A metal having a relatively high standard reduction potential among the two or more metal salts used as the first metal salt and the second metal salt is referred to as a first metal salt and a metal having a relatively low standard reduction potential is referred to as a second metal salt. The standard reduction potential (0.000 V) of the standard hydrogen electrode in the present specification is compared with the degree of difficulty in reducing the metal ion of the metal salt compared to the hydrogen ion, , The sign of the standard reduction potential is (-), and the larger the absolute value, the higher the 'standard reduction potential'.

In the case of acid, it is ionized and electricity such as hydrochloric acid, sulfuric acid, methanesulfonic acid (MSA), nitric acid, boric acid, acetic acid, organic sulfuric acid, citric acid, formic acid, ascorbic acid, hydrofluoric acid, phosphoric acid, amino acid, hypochlorous acid Sulfuric acid, which is easy to obtain at low cost, is used in the examples.

In the case of additives, the surface of the plated film is made uniform, and a leveling agent (smoothing agent), an accelerator and an inhibitor may be added. In addition, various additives such as a defoaming agent, a polishing agent, a particle refining agent and the like may be used in some cases. In the examples, polyoxyethylene lauryl ether (POELE) was used as an additive in the flattening agent, but it is possible to form a multilayer film without using it.

The electrolytic plating circuit forming step S110 is a step of forming the electrolytic plating circuit by immersing the reference electrode 12, the anode 13, and the cathode 14 in the water-based alloy plating solution 15 and then connecting the power source. That is, in the electrolytic plating circuit forming step S110, the electron movement of the circuit moves in the order of the anode 13, the power source, and the cathode 14.

The reduction potential or current application step (S120) is a step of inputting and applying a reduced potential (voltage) or current through the software of the PC 20 which is a control unit. At this time, a voltage or a current is input in the form of a square pulse when the reduction potential or the current application step (S120) is performed. The pulse voltage and the current are applied to the first application period where the first metal is dominantly plated, The second application period is repeated.

Each section may be represented by a change in input voltage or current over time, i.e., a plating voltage (or current) and a duration. In a first application period, a first voltage (or a corresponding current) is applied for a first time , And the second application period represents a pulse shape in which the second voltage (or the corresponding current) is applied for the second time.

The thickness condition input step S130 of the plated thin film is a step of inputting a voltage or a corresponding current, time and cycle number corresponding to the plating thickness having a desired heat generating characteristic for the first plating layer 33 and the second plating layer 34, Through the software of FIG.

More specifically, the first plating layer 33 as the interval is that during a first interval is applied to the first voltage (V ₁₎ which is formed a first time (t _1), the first voltage (V ₁₎ is at 0V -4.5 V, more preferably between 0V and -1.67V. The first voltage (V ₁ ) is applied at a voltage at which the first metal is predominantly plated.

The adjusting the thickness of the first plating layer by adjusting a one hour (t _1), and a first time (t ₁₎ is first formed in a first application zone in the _{0 <t 1 ≤ 10 (min} ) Range The first time (t ₁ ) is determined so that the single thickness of the one plating layer becomes 10 nm to 150 nm.

Also, the second plating layer 34, as applied during the period in which the second section is applied to the second voltage (V ₂₎ which is formed the second time (t _2), between the second voltage (V ₂₎ is at 0V -4.5V , More preferably between 0 V and -1.67 V. The second voltage (V ₂ ) is applied at a voltage at which the second metal is predominantly plated.

The adjusting the composition and thickness of the second plating layer over the control of two hours (t _2), and a second time (t ₂₎ is formed in one second is region within _{0 <t 2 ≤ 200 (min} ) Range The second thickness is determined so that the single thickness of the second plating layer becomes 10 nm to 150 nm. The second time t ₂ is preferably 0.5 to 20 times the first time t ₁ .

When the first application section and the second application section are plated one time each, it is assumed that one cycle is one cycle, the bonded material according to the present invention has at least one cycle and at least one first plating layer and at least one second Plating layer should be included. Preferably at least 6 cycles, so that at least 6 layers of the first plating layer and at least 6 layers of the second plating layer are repeatedly formed.

The first time period t ₁ and the second time period t ₂ are set so that the total thickness of the multilayered plating layer including at least one layer of the first plating layer and the at least one layer of the second plating layer is set to be 1 Adjust the total time that the cycle repeats.

 That is, in the step of inputting the thickness condition of the plated thin film (S130), the thickness of the plating layer having the exothermic characteristics of the first and second interlayer layers is adjusted by adjusting the voltage between 0 V and -4.5 V or the corresponding current and time according to the thickness condition . Preferably, in the present invention, the thickness of the plating layer having the exothermic characteristics of the first and second regions can be controlled by controlling the voltage between 0 V and -1.67 V or the corresponding current and time.

Elements when the reduction potential is higher than -1.67V (for example, Li, Na, Ca, etc.) are difficult to be reduced by the plating method of the present invention, and it is difficult to form the noble metal material when the potential is lower than 0V. In addition, if it is 0 V or less, metal etching may occur and the plating layer may not be formed well.

The multi-layer plating step S140 is a step of acquiring a bonding material through sequential plating of the first plating layer 33 and the second plating layer 34. The metal salt in the plating solution is in the ionized form. In order to reduce the metal salt in the plating solution, a voltage higher than the reduction potential of each element must be applied. As described above, by repeatedly applying the first voltage and the second voltage, The layer predominantly precipitated and the layer predominantly precipitating the second metal are alternately displayed. The number of alternating plating layers is unstable because the surface area between the plating layers is wider as the number of layers is increased. However, the current density at plating should not exceed the limit current density.

On the other hand, the bonding material is a first plating layer 33 formed after one cycle in which the first applying period and the second applying period are repeated once so that the first plating layer 33 and the second plating layer 34 can exhibit heat generating characteristics, And the thickness of the second plating layer 34 is set to a thickness ranging from 0.1 nm to 5 占 퐉.

In addition, it is preferable that each of the amorphous metal plating films such as the first plating layer 33 and the second plating layer 34 in the bonded material has a laminated structure of at least six layers or more. When each of these amorphous metal plating films is less than 6 layers, the endothermic reaction occurs more than the exothermic reaction at the time of bonding, and the crystalline phase of the amorphous bonding material is not changed to the crystalline state, so that the bonding strength of the bonding portion is lowered and the bonding reliability is lowered It is not preferable.

Furthermore, the number of multiple layers can easily be controlled by the number of dislocation cycles in the multi-layer plating step (S140).

The reduction potential difference between the first metal salt and the second metal salt was measured and the reduction potential or the current application step for manufacturing the bonded material in which the first plating layer 33 and the second plating layer 34 of the present invention were alternately plated S120).

At this time, the step of measuring the reduction potential difference of the metal salt may include a step S200 of preparing an alloy plating liquid, an electrode preparing step S210, an electrolytic plating circuit forming step S220, a power applying step S230, And measuring the reduction potential and current of the metal to be plated. The reason for measuring the reduction potential of the metal salt is to give a voltage higher than the potential at which these metals are reduced so as to form the first plating layer and the second plating layer to be.

Here, the alloy plating solution preparation step (S200), the electrode preparation step (S210), the electrolytic plating circuit forming step (S220), and the power applying step (S230) are the steps of preparing the electrode and aqueous alloy plating solution Step S100, the electrolytic plating circuit configuration step S110, and the reduction potential or current application step S120, detailed description thereof will be omitted.

If the reduction potential is known, the method of manufacturing the bonded material can be carried out immediately. Meanwhile, the polarization curve measuring step (S240) and the reducing potential of the metal to be plated and the current measuring step (S250) may be performed only once but not once again. Furthermore, a method for measuring the reduction potential difference is to measure a Tafel curve (a constant voltage per unit time is changed, and a current density at that time is represented by a hysteresis curve, and a section where a change in slope is represented by a reduction potential).

As a result, the bonded material produced by the method of manufacturing a bonded material of the present invention can easily form a laminate up to a nanometer thickness so as to have a heat generating characteristic, and can increase the number of laminated layers to several tens of thousands or more.

4, the bonding material 30 manufactured by the method of manufacturing a bonded material according to the present invention includes a first plating layer 33 on a conductive substrate 31 having an insulating tape 32 at its edges, And the second plating layer 34 are sequentially stacked. In this case, the first plating layer 33 is a first applied region plating layer in which the first metal is plated predominantly than an alloy or a second metal of the first metal and the second metal, Refers to an alloy of the first metal and the second metal or a second applied section plating layer which is predominantly plated over the first metal.

The bonding material can be implemented in a form in which a plurality of different types of plating layers are alternated from several layers to several tens of layers or more, thereby further improving the bonding property.

On the other hand, the low-temperature bonding of the base material on which the bonding material is formed is performed in a vacuum, an inert gas, or a reducing gas atmosphere, which is an atmosphere that does not cause oxidation of the bonding surface, and may be performed using a flux in the air.

The bonding material may be a multi-layered plated film on the surface of the base material, a multilayer foil sheet in the form of a multilayer foil sheet, a powder or ball in which the bonding material is formed on the surface of the multilayer foil sheet, A paste form prepared by mixing powders in which a sheet is formed by pulverizing particles or a bonding material with a liquid, and the like, may be disposed in the joint portion of the base material and used as a bonding medium.

The liquid in the paste form can be used as a solvent, for example, alcohols, phenols, ethers, acetone, aliphatic hydrocarbons having 5 to 18 carbon atoms, aromatic hydrocarbons such as kerosene, diesel, toluene, xylene, Among them, alcohols, ethers, or acetones having preferably some solubility in water may be used.

The base material (material to be bonded) may be selected from the group consisting of metals, ceramics, and high molecular materials.

The base material (bonding material) forming the bonding material according to the present invention has a heat generating characteristic and can be bonded at a lower temperature than a conventional bonding medium in a bulk form.

Preferably, the bonding material is a bonding material for low-temperature bonding which bonds the base material and the bonding material by an exothermic reaction caused by a change in crystal phase from amorphous to crystalline. That is, the bonding material is formed in the form of a multi-layered plated film including a metallic element exhibiting an exothermic reaction upon alloying, and when the base material and the bonding material are bonded, the bonding material and the bonding material are bonded by an exothermic reaction caused by a change in crystal phase from amorphous to crystalline So that the bonding can be easily and stably performed at a low temperature. Further, the bonded material changed from the amorphous state to the crystalline state exhibits excellent bonding strength by firmly and stably bonding the base material and the material to be bonded.

The present invention also provides a bonding material comprising at least two or more metals exhibiting an exothermic reaction upon alloying and comprising at least two layers of amorphous metal plating films.

More specifically, a bonding material comprising at least two or more amorphous metal plating films containing at least two metals whose difference in standard reduction potential is not less than 0.029 V and not more than 1.0496 V, and which is solidified after melting to bond the materials to be bonded, The amorphous metal plating film undergoes an exothermic reaction during the initial melting, and the initial melting temperature (T _m1 ) provides a bonding material having a temperature lower than the temperature (T _m2 ) after the solidification.

The bonding material preferably has a structure in which the amorphous metal plating film has a lamination structure of six or more layers of plated layers and is preferably used as a bonding material at a temperature lower than the melting point of the entire bulk composition constituting the plating layer of the amorphous metal plating film, The bonding material is preferably a material for low-temperature bonding which bonds the base material and the material to be bonded by an exothermic reaction caused by a change in crystal phase from amorphous to crystalline.

The metal may be selected from the group consisting of Sn, Cu, Zn, Ni, Al, Ti, V, Cr, Mn, Fe, Co, Ga, Ge, As, Zr, Nb, Mo, Ru, Rh, Pd, At least one metal selected from the group consisting of Sb, Te, Hf, Ta, W, Re, Os, Ir, Pt, Au, Tl, Pb and Bi may be used. Two or more metal elements showing a difference in reduction potential can be selected and used.

When the amorphous metal plating film is laminated on two plating layers, it is preferable that the total thickness of the two amorphous metal plating films is in the range of 0.1 nm to 5 μm, and the total thickness of the amorphous metal plating film is 0.6 nm Lt; RTI ID = 0.0 &gt; um. &Lt; / RTI &gt;

The bonded material according to the present invention can bond the base material and the material to be bonded at a low temperature due to heat generation and amorphous characteristics and has excellent heat resistance characteristics because it is not melted at a low temperature once bonded.

More specifically, the amorphous metal plating film according to the present invention undergoes an exothermic reaction during the initial melting, and the initial melting occurs at a temperature lower than the melting point (T _ma ) of the entire bulk composition constituting the amorphous metal plating film during heating for bonding. In addition, the temperature (T _m1 ) at which the initial melting is lower than the temperature (T _m2 ) at which it is melted after solidification.

This is because the amorphous metal plating film changes to a crystalline state by heating and is caused by the exothermic reaction that occurs in this process. The amorphous characteristics of the bonded material produced by the lamination of the individual metal layers of different metals to the nanometer scale level are accompanied by the instability of the amorphous phase and the exothermic reaction in the phase change of the crystalline phase. Further, the surface area between the laminated plated layers becomes wider and becomes more unstable and melts by an exothermic reaction at a temperature lower than the melting temperature (T _ma ) of the bulk composition.

In addition, the bonding material according to the present invention, since the bonding to the first melting the base material and the target bonding material was solidified by cooling it the case of re-melting, the first melting point (T _m1) primary melting temperature (T _m1 does not become molten at ). &Lt; / RTI &gt; That is, when the bonding material according to the present invention is first heated and then cooled and then heated again, the temperature at which the melting occurs is referred to as a second melting temperature ( _Tm2 ), and _Tm2 > _Tm1 .

This is due to the alloying effect of the first metal and the second metal due to the interdiffusion occurring in the process, as the bonding material changes from an amorphous state to a crystalline state due to heating at the time of bonding, and the multilayer film disappears. The bonding material changes from an amorphous state in an unstable state to a crystalline state in a stable state through primary heating, and secondary melting occurs at a temperature higher than the primary melting temperature upon reheating after cooling. When the bonded material according to the present invention is heated to bond the base material and the material to be bonded, the amorphous state changes from an unstable state to a crystalline state, which is stable, and secondary melting occurs at a temperature higher than the primary melting temperature. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 6 is a photograph showing a current, a potential and a plating power supply apparatus in which a first plating layer of the first section is plated, and FIG. 7 is a graph showing a current, a potential, A recorded picture of a power supply unit is disclosed.

FIG. 8 is a table showing the formation of a bonding material according to a content ratio of a metal salt and a difference in reduction potential in a plating solution according to the present invention. FIGS. 9A to 9H show the first metal salt and the second metal salt in the plating solution according to the present invention. Sectional view of the bonding material in which the types of the metal salt and the reducing potential are different from each other is shown in FIG. 10, and FIG. 10 shows the formation of the bonding material according to the content ratio of the metal salt and the reduction potential in the plating solution according to the present invention A range graph is shown.

11 shows a scanning electron microscope (SEM) photograph showing a cross-section of a Sn-Cu multilayered plated film formed by the method for producing a bonded material of the present invention. Fig. 12 shows a cross section of an individual plated layer 13 is a scanning electron microscope (SEM) photograph showing a cross-section of a thick Sn-Cu multilayer plated film produced by the method of the present invention, (SEM), and FIG. 14 is a sectional view of a bonded material in which a first plating layer, a second plating layer, and a third plating layer are alternately laminated when a third metal salt is added to the metal salt according to the present invention .

Fig. 15 is a graph showing the conditions under which the metal is oxidized and reduced in order to explain a method of bonding at a low temperature using the bonding material of the present invention.

FIG. 16 is a graph showing the thermal characteristics of the Ni-Cu bonded material produced by the present invention measured by DTA (differential thermal analysis) during heating, and FIG. 17 is a graph showing the Ni- Temperature bonding of 304 stainless steel at 600 ° C, 700 ° C, 800 ° C, and 1000 ° C for 10 minutes. FIG. 18 is a graph showing the results of the low temperature bonding of 900 stainless steel using 900- Temperature tensile test after 304 low-temperature jointing of 304 stainless steel for 10 minutes.

FIG. 19 is a graph showing the thermal characteristics of the Sn-Cu bonded material produced by the present invention measured by differential scanning calorimetry (DSC). FIG. 20 is a graph showing the Sn- which discloses a one picture form a material on a copper substrate, 21 is by using the bonding material of Sn-Cu bonding material manufactured by the method according to the invention in the bonding medium 160 in a 10 ^-3 torr, or in the vacuum atmosphere A low temperature bonding of the copper plate for 10 minutes at respective temperatures of 占 폚, 170 占 폚 and 210 占 폚 is disclosed.

FIG. 22 is a graph showing the thermal characteristics of the Cu-Ag bonded material produced by the method of manufacturing a bonded material according to the present invention when measured by DTA. FIG. 23 is a graph showing the Sn (Left) of the first and second plating layers in a plated state of the Cu bonding material and a photograph (right) of the first and second plating layers disappearing due to diffusion after heating.

FIG. 24 is a photograph (left) of the first and second plating layers in a state of being plated before heating of the Ni-Cu bonded material produced in the present invention and a photograph of a state in which the first and second plating layers are extinguished (Right). FIG. 25 is a graph (blue) showing the amorphous characteristics and a graph (red) showing the crystalline characteristics as a result of XRD analysis after heating according to the XRD analysis of the Sn-Cu bonded material produced in the present invention .

FIG. 26 shows an electron microscope (SEM) photograph showing a cross-section of a multi-layered metal material produced by thickening the sum of the thicknesses of the two plated layers to 5 .mu.m. FIG. 27 shows the sum of the thicknesses of the two plated layers 28 shows a heating graph in which the thickness of the coating layer is 5 占 퐉 and the thermal property is measured using a differential scanning calorimeter (DSC). Fig. 28 shows a heating graph in which a multi- FIG. 29 shows an optical microscope photograph showing a cross-section of a copper electrode made by laminating six layers of a multi-layered metal material to form a low-temperature bonded structure.

30 shows an optical microscope photograph showing an end face portion of a Sn-Cu-based metal plating thin film produced by lengthening the plating time of a multilayer metal material to have a total plating thickness of 300 mu m.

Hereinafter, with reference to these drawings, specific examples of the method for producing a bonded material of the present invention will be described.

For example, a process of forming a multi-layered plated film by a method of manufacturing a bonded material using the plating method of the present invention will be described.

[Example 1]

In this embodiment, the plating was performed by dissolving the first metal salt and the second metal salt in a molar ratio of 1: 1 to 200: 1 in the alloy plating solution. 8 and 9A to 9H, when the ratio of the first metal salt to the second metal salt is less than 2: 1, for example, when the ratio of 6: 4 and 5: 5 is satisfied, the first and second plating layers The difference in the concentration of the second metal is reduced and the bonding material is not formed. If the ratio of the first metal salt to the second metal salt exceeds 100: 1, for example, when the ratio of the first metal salt to the second metal salt is in the range of 200: 1, the second metal salt is easily consumed during plating and the concentration of the second metal salt becomes thin, Instead, the hydrogen ions in the plating liquid are reduced to generate hydrogen bubbles. Therefore, it is difficult to form the bonding material.

Further, in order to determine the first and second metal salts forming the bonding material, a metal salt of an element having a standard reduction potential of 0.004 V or more and 1.5614 V or less was selected and multilayer plating was performed (FIGS. 8 and 9A to 9D 9h). When the reduction potential difference of the first and second metal salts is reduced to less than 0.029 V, the first and second metal salts are reduced when the first and second plating layers are formed, and the boundary between the plating layers disappears and the multilayered thin film is not formed. In addition, when the reduction potential difference of the first and second metal salts exceeds 1.0496 V, the second metal interferes with the plating of the first metal, so that the boundary between the plating layers also disappears and the multilayered thin film is not formed.

9A to 9H show cross sections of the bonded materials corresponding to the respective conditions of FIG. 8, and it is possible to confirm by photographs whether or not the bonded materials are formed according to the plating conditions. The numbers in Figs. 9A to 9H correspond to the numbers in Fig. For example, the photograph of the condition 2-3 'in FIG. 8 shows the photograph' 2-3 'in FIGS. 9A to 9H.

FIG. 10 is a graph showing the range of conditions under which the multilayer plating is formed as a result of FIG.

As a result, in the production method according to the present invention, a metal salt having a reduction potential difference of 0.029 V or more and 1.0496 V or less in the reduction potential between the first metal salt and the second metal salt in the plating solution is used, 2 metal salt is preferably in the range of 2: 1 to 100: 1.

[Example 2]

200 ml of a sulfuric acid-based Sn-Cu alloy plating solution was prepared in order to form a multi-layer plated film of Sn and Cu.

SnSO ₄ : 17.175 g

CuSO ₄ .6H ₂ O: 1.998 g

H ₂ SO ₄ : 10.72 ml

HCl: 0.03 ml

POELE: 0.8g

The plating conditions were as follows: the plating voltage was -0.6 V, the current density was -30 mA / cm ² , the plating time was 30 seconds, the plating voltage was -0.45 V, the current density was -2 mA / cm ² , and the plating time was 2 minutes. The first and second sections were repeated 400 times each (400 cycles).

As a result of the plating, it can be confirmed that the Sn rich layer having a thickness of 600 nm and the Cu rich layer having a thickness of 100 nm are alternately plated by 400 layers, respectively, as shown in FIG.

Using the same plating solution, when the plating current or plating time was increased, the Sn and Cu layers were alternately plated thicker. The plating conditions were as follows: the plating voltage was -0.6 V, the current density was -30 mA / cm ² , the plating time was 10 minutes, the plating voltage was -0.45 V, the current density was- ² mA / cm ² , and the plating time was 10 minutes. The first and second sections were repeated five times each (5 cycles).

As a result of the plating, it can be confirmed that the Sn rich layer having a thickness of 7 탆 and the Cu rich layer having a thickness of 10 탆 are alternately thickened by five layers each in FIG. 12.

[Example 3]

A process of forming a Zn-Ni multi-layered plating film by a method of manufacturing a bonded material using the plating method of the present invention is as follows.

First, 200 ml of a sulfuric acid-based Zn-Ni alloy plating solution was prepared to form a Zn and Ni multi-layered plating film, followed by plating.

ZnSO ₄ -7H ₂ O: 46.0 g

NiSO ₄ -6H ₂ O: 4.20 g

H ₂ SO ₄ : 4 ml

HCl: 0.03 ml

POELE: 0.8g

As shown in Fig. 13, a Zn-rich layer having a thickness of 6 탆 and a Ni-rich layer having a thickness of 3 탆 were alternately plated by 20 layers each. The plating conditions were as follows: the plating voltage was -1.8 V, the current density was -250 mA / cm ² , and the plating time was 10 minutes in the first application period, the plating voltage was -1.2 V, 100 mA / cm ² , and the plating time was 10 minutes. The first and second application intervals were repeated 20 times each for 20 cycles.

Further, although not shown in the drawing, if the same plating solution is used and the plating current or plating time is increased, the Zn-rich layer and the Ni-rich layer are alternately plated thicker.

When a third metal salt is additionally added to the plating solution of the above [Examples 1, 2 and 3] and the reducing potential of the metal salt is applied, a third metal precipitates and the first plating layer, the second plating layer, Layered plating film can be formed. A sectional view of the formed plating layer is shown in FIG. 14, and a structure in which a multilayer thin film layer composed of the first plating layer 42, the second plating layer 43, and the third plating layer 44 are alternately laminated is shown on the base material 41 .

15 is a graph showing conditions under which an oxide film of the material to be bonded is removed, that is, reduction is performed to explain a method of bonding at a low temperature using a bonding material using the plating method of the present invention. In the soldering and brazing joints of metals, the oxide layer on the surface of the bonding material greatly reduces the bonding property. Since ordinary metals except precious metals, such as gold, form a surface oxide layer in an atmospheric ambient atmosphere, in order to achieve good bonding, the oxide layer on the surface must be removed by adjusting the temperature and the bonding atmosphere. The bonding material of the present invention is unstable due to an increase in the surface area between the laminated plated layers, and diffusion and melting of the atoms can be easily performed at a low temperature, thereby enabling bonding at a low temperature. At this time, the bonding is performed at a temperature equal to or higher than the temperature at which the oxide film on the surface of the bonding material of Fig. 15 is removed.

In the graph of FIG. 15, the X axis represents the temperature and the left Y axis represents the dew point temperature in the atmosphere containing hydrogen at the time of bonding, and the right Y axis represents the degree of vacuum or the partial pressure of water vapor in the vacuum atmosphere at the time of bonding. In the figure, the upper part of each curve is stable in the state of the metal oxide and the lower part of the curve is stable in the state of the metal being reduced. In order for the material to be bonded to be brazed or soldered, the temperature and atmosphere of the reduction zone belonging to the lower part of the oxide curve of Fig. 15 are necessarily required. The atmosphere can also be created using chemicals (brazing, soldering flux) that remove oxides when in the atmosphere.

For example, all stainless steels contain chromium. In order to bond stainless steel, chromium oxide must be reduced to chromium because the chromium oxide is strong in stainless steel. That is, maintaining the temperature and atmosphere below the chromium oxide (Cr ₂ O ₃ ) curve indicated by number 1 in FIG. 15 is indispensable for brazing and soldering stainless steels. For example, when the bonding atmosphere is maintained at 10 ^-2 torr, the chromium oxide (Cr ₂ O ₃ ) on the surface is reduced to chromium at a temperature of 800 ° C or higher and maintained at 10 ^-3 torr at a temperature of 600 ° C or higher So that the joining of the stainless steel becomes possible. When 10 ^-5 torr is maintained, the chromium oxide (Cr ₂ O ₃ ) on the surface is not present at a temperature of 500 ° C. or higher, so that stainless steel bonding is also possible. When joining in a reducing gas atmosphere containing hydrogen, the dew point of the left Y-axis may be used instead of the degree of vacuum.

However, when a Ni-Cu-based alloy (bulk material) is used as a bonding medium for bonding stainless steel in general, the melting point increases as Ni increases. Therefore, the lowest melting temperature is 100% Cu-0% Ni Lt; RTI ID = 0.0 &gt; 1083 C, &lt; / RTI &gt; Therefore, a normal bonding temperature (for example, a brazing temperature of a Ni-Cu bulk alloy or stainless steel using Cu or Ni as a bonding medium) using a Ni-Cu bulk alloy as a bonding medium is approximately 1200 ° C or higher.

On the other hand, when the Ni-Cu bonding material prepared by the manufacturing method of the present invention is used as a bonding medium, the surface area is wide and unstable, and an exothermic reaction occurs during interdiffusion of atoms between the multilayer thin film layers at low temperatures during heating. At this time, the Ni-Cu bonding material melts at a low temperature, and as shown in Example 4, the stainless steel can be bonded at a low temperature at a temperature of 900 ° C or lower. In addition, bonding can be performed at 800 ° C or 700 ° C or less depending on the plating conditions of the bonded material. Thus, it can be seen that the content of the graph of Fig. 15 conforms to the fact that bonding is possible in the reduction region where the surface oxide of the material to be bonded is removed.

When the Ni-Cu bonding material of the present invention is used as a bonding medium in comparison with the bonding temperature (1200 ° C) of the stainless steel of the conventional general bulk Ni-Cu bonding medium alloy, the bonding temperature is 200 to 600 ° C lower, Is only 50 ~ 83% of the junction temperature. Therefore, the energy saving rate of the bonding method using the Ni-Cu bonding material is 17 to 50%. Of course, a similar effect can be obtained in ordinary carbon steel containing no chromium (in FIG. 14, FeO is located on the upper left side of Cr ₂ O ₃ ).

[Example 4]

The Ni-Cu bonding material developed in the present invention diffuses at a low temperature between the laminated plated layers and when heat is generated and measured by DTA, the melting point is lower than that of Cu (melting point 1083 ° C) and Ni (melting point 1445 ° C) Peaks appear at 567 ° C, and the Ni-Cu bonding material melts. The thermal properties of the Ni-Cu bonded material at this time were measured by DTA and are shown in FIG. The peak in Fig. 16 corresponds to about 52.3% of the lowest melting point of 1083 캜 of the Ni-Cu-based alloy. The results show that the melting point of Ni-Cu bonding material is lower than that of Cu (melting point 1083 ℃) and Ni (melting point 1445 ℃), which are the elements of the plating layer, and the lowest melting point of Ni-Cu bulk alloy is 1083 ℃ 304 stainless steel was bonded at low temperatures at low temperatures of 600 ° C, 700 ° C, 800 ° C, 900 ° C and 1000 ° C. Layer metal plating thin film is melted at a temperature lower than the melting point of Cu (melting point: 1083 DEG C), Ni (melting point: 1445 DEG C) and the lowest melting point of these bulk alloys due to the exothermic effect of the multilayered metal-plated thin film.

Specifically, a Ni-Cu bonding material was formed on a 304 stainless steel sheet having a size of 30 X 10 X 0.3 (mm). Stainless steel specimens with bonded materials were stacked facing each other with uncoated stainless steel specimens and bonded at 600 ° C, 700 ° C, 800 ° C, 900 ° C and 1000 ° C for 10 minutes using a vacuum of 10 ^-4 torr. The results are shown in Fig. Stainless steel specimens bonded at 900 ℃ were subjected to tensile test. The tensile strength reached 117kgf.

FIG. 18 shows the wavefront of the joint at this time, and it can be confirmed that the multilayered plated thin film is well bonded.

On the other hand, the iron oxide (FeO) indicated by 2 in FIG. 15 exists in the upper left of the figure and is much easier to be reduced than the chromium oxide. That is, as shown in the graph, at a temperature of 100 ° C or more, FeO is reduced to Fe metal and a good low-temperature bonding can be achieved. In addition, at a high degree of vacuum of 10 ^-3 torr or less, Fe is present even at a temperature of 100 ° C or lower, so that good low-temperature bonding can be achieved.

The metal group Au, Pt, Ag, Pd, Ir, Cu, Pb, Co, Ni, Sn, Os and Bi shown in FIG. 15 are present in the upper left part of the graph, It can be seen that it is easier to remove and that bonding can be performed at a lower temperature (for example, 100 ° C or less) than that under which FeO is reduced, or even if the vacuum and reducing atmosphere is worse.

On the other hand, the lowest melting point of the Sn-Cu alloy (bulk material) is 227 ° C (eutectic temperature) when the composition is 99.3% Sn-0.7% Cu. When a Sn-Cu alloy is used as a bonding medium, the bonding (soldering) temperature is about 260 to 270 ° C, which is about 40 ° C higher than the melting point. For example, when an electronic component is soldered to a brazing material having a composition of 99.3% Sn-0.7% Cu, the soldering temperature is about 260 to 270 ° C.

On the other hand, when the Sn-Cu bonding material developed in the present invention is used as a bonding medium, the bonding material is unstable due to its wide surface area, and an exothermic reaction occurs due to interdiffusion of atoms at low temperature between the laminated plating layers during heating (see Example 5) . At this time, the Sn-Cu bonding material melts at a low temperature and has a melting point lower than that of Sn (melting point 232 ° C) and Cu (melting point 1083 ° C), which are elements of the plating layer, as shown in Example 5, Copper can be bonded at a low temperature of 160, 170 and 210 ° C, which is lower than the melting point of 227 ° C. Therefore, when a Sn-Cu bonding material manufactured by the present invention method is used as a bonding medium in comparison with a bonding temperature (260 to 270 ° C) in which a conventional general bulk Sn-Cu alloy is used as a bonding medium (solder) The junction temperature is 50-110 ° C lower, and the percentage is only 59-81% of the junction temperature. As a result, the energy saving rate of the bonding method using the Sn-Cu bonding material is 19 to 41% of that of the conventional Sn-Cu-based solder.

[Example 5]

The Sn-Cu bonding material developed in the present invention diffuses at a low temperature and generates heat. When measured by DSC, a peak appears at 144 ° C, and the Sn-Cu bonding material melts. The thermal properties at this time are measured by DSC and are shown in Fig. The peak in Fig. 19 corresponds to about 63.4% of the lowest melting point (eutectic temperature) of 227 캜 of the Sn-Cu-based alloy. As shown in FIG. 19, the copper plate was bonded at 160 ° C., 170 ° C., and 210 ° C. at a low temperature using the Sn-Cu bonding material as a bonding medium. Specifically, a Sn-Cu bonding material was formed on a Cu plate having a size of 30 X 10 X 0.3 (mm). A photograph of the Sn-Cu bonding material formed at this time is shown in FIG. Cu specimens with Sn-Cu bonding material were laminated facing the plated layer and bonded at low temperatures of 160 ° C, 170 ° C and 210 ° C for 10 minutes in air or a vacuum of 10 ^-3 torr. FIG. 21 shows a joint photograph at this time. The tensile strength of the specimens bonded at 170 ℃ reached 38kgf.

In Example 5 of the present invention, copper was bonded at a temperature of 160 ° C or higher in the atmosphere or in a vacuum of 10 ^-3 torr, and in Example 4, stainless steel was bonded at a temperature of 600 ° C or higher in a vacuum of 10 ^-4 torr . These bonding examples are shown in Fig. As a result, when the bonding material produced by the method of the present invention is used as a bonding medium, it can be seen that the bonding at a low temperature is possible at a temperature higher than the corresponding temperature in the region where the bonding material is reduced. The highest bonding temperature, of course, is below the melting point of the bonding material.

In another embodiment, a multilayered nanotube film exhibiting Cu-Ag heating and amorphous characteristics was prepared by the present invention, and the thermal characteristics at this time were measured by DTA and shown in FIG. At this time, a peak appears at 678.54 ° C, which is lower than the melting points of Ag (melting point 961 ° C) and Cu (melting point 1083 ° C), which are elements of the plating layer due to heat generation characteristics. eutectic temperature, Cu-40% Ag), which is about 87.1% of 779 ℃.

From the experimental results of the above thermal characteristics, it was found that the bonded material produced through the present invention has a bulk density of not higher than 52.3% (Ni-Cu system multilayer thin film) or more of 87.1% (Cu-Ag system multilayer thin film) In this temperature range where peaks appear in the temperature range and the conventional bonding medium does not melt so that the bonding (brazing, soldering) is impossible, the present invention can be used to melt the bonding medium by the exothermic reaction, ) Is possible. Naturally, even at the above-mentioned temperature of 87.1% or higher, bonding can be carried out by using the medium of the present invention, and the upper limit of the bonding temperature ranges from the melting point of the existing bonding medium or the melting point of the bonding material.

The bonding material of the present invention has a layered structure in a plated state, but when used as a bonding medium for low temperature bonding, the first and second plated layers of the bonding material disappear due to mutual diffusion when heated, . A Sn-Cu-based multi-layered nano-thin film layer having a heat generation characteristic was formed and heated at 160 ° C to confirm that the multi-layered nano-film layer was extinguished. FIG. 23 shows the first and second plating layers before the heating of the Sn-Cu bonding material at this time and the first and second plating layers disappear due to diffusion after heating.

Further, a Ni-Cu bonding material was formed and heated at 650 ° C to confirm that the multi-layered nano thin film layer was extinguished. FIG. 24 shows the first and second plating layers before the heating of the Ni-Cu based multi-layered nano thin film layer and the disappearance of the first and second plating layers due to diffusion after heating.

In addition, the phase was analyzed using XRD to confirm the amorphous phase characteristics of the bonded material. The graph (blue) showing the amorphous characteristics and the graph (red) showing the crystalline characteristics as a result of the XRD analysis after heating showed that the Sn-Cu bonded material produced by the method of the present invention exhibited the amorphous characteristics, Is shown in Fig. (Sn rich layer) and a second plating layer (Cu rich layer) were formed as compared with an XRD graph (yellowish green) showing a long range order, which is a crystalline property of an unplated Cu plate as shown in FIG. 25, In the case of before, a broad peak showing a short range order of amorphous characteristics is observed between 2 and theta values of 5 to 20 (deg), and it can be confirmed that the amorphous characteristic (blue) Thereafter, a broad peak between 2 and 5 theta values of 5 to 20 (deg.) Disappears and crystallographic properties (red) can be confirmed.

[Comparative Example 1] A multilayered metal material having no exothermic reaction

If the thickness of each layer of the multilayer metal plating layer becomes thicker or the number of plating layers decreases, the area of the interface in the multilayer metal plating layer becomes smaller. In this embodiment, a Sn-Cu-based bonding material having a thickness of 5 μm and a thickness of two layers is prepared so as not to generate an exothermic reaction. The cross section of the Sn-Cu multi-layer material manufactured to have a total thickness of 5 占 퐉 of the two layers at this time was confirmed by an electron microscope and is shown in Fig. The thermal characteristics of the multi-layer material were measured by DTA and are shown in Fig. As a result, the DSC measurement did not show a low-temperature exothermic peak, and an endothermic peak appeared at 228 ° C at which the tin, which is an element constituting the plating, melts at a high temperature. That is, an exothermic peak at 144 ° C, which was exhibited in a Sn-Cu-based bonding material prepared by thinning the thickness of the two layers to 40 nm, was not found in the thick-made 5 μm thick material.

In order to avoid the exothermic reaction at this time, the semiconductor was heated to a copper electrode at a temperature of 170 ° C using a material in which each plating layer was made thick. The junction between the semiconductor and the electrode at this time was observed by an optical microscope and was not bonded. The result is shown in Fig. The bonding material in which each of the plated layers is made thick can be judged not to be bonded because only the endothermic peak is shown by the thermal analysis and the endothermic quantity is larger than the calorific value.

In addition, a Sn-Cu multilayered metal plating thin film having 6 layers of plating layers was prepared, and the copper electrode was bonded at a low temperature of 160 ° C, and a cross section thereof is shown in FIG. The joints at this time were partially bonded. This is because the amount of the plated layer was insufficient and the amount of molten metal was not sufficient.

In addition, the plating time was elongated to produce a Sn-Cu-based multilayered metal plating thin film having a total plating thickness of 300 m, and a cross section at this time is shown in Fig. The multilayered metal thin film produced by the present invention may have defects on the surface of the plating layer as the plating progresses. When the defects grow continuously on the vertical surface and the plating layer is formed to a thickness of 300 탆 or more, the proportion of defects in the multilayered plating layer increases, The plating layer is not well formed, the amorphous and exothermic characteristics are not exhibited, and the low temperature bonding is not achieved.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the equivalents of the appended claims, as well as the appended claims.

10: Device for manufacturing bonded material
11: container
12: Reference electrode
13: anode
14: cathode
16: Magnetic for stirring
20: PC
30: Bonded material
31: conductive substrate
32: Insulation tape
33: First plating layer
34: Second plating layer
41: Plated substrate
42: First plating layer
43: Second plating layer
44: Third plated layer

Claims (18)

Preparing an aqueous alloy plating solution containing two or more metal salts including a first metal salt and a second metal salt;
Immersing the electrode in the aqueous alloy plating solution to form an electrolytic plating circuit;
Applying a voltage or a corresponding current value according to a reduction potential value of the metal salt to be plated to a control unit for controlling the electrolytic plating circuit to apply a reduction potential to the electrode; And
Forming an amorphous metal plating film including the first metal, the second metal, and an alloy of the first metal and the second metal, the method comprising:
The step of applying the reduction potential may include applying a square pulse voltage including a first application period for applying the first voltage (V ₁ ) and a second application period for applying the second voltage (V ₂ )
Wherein the first voltage (V ₁ ) is higher than the second voltage (V ₂ )
Wherein the first voltage (V ₁ ) and the second voltage (V ₂ ) are voltages between 0V and -4.5V.
The method according to claim 1,
Wherein the range of the reduction potential value of the metal salts is from + 1.83V to -1.67V.
The method according to claim 1,
Wherein the water based alloy plating solution further comprises a first metal salt, a second metal salt, an acid, and an additive in a plating solution based on water.
The method of claim 3,
Wherein a concentration ratio of the first metal salt and the second metal salt in the plating solution is in the range of 2: 1 to 100: 1.
The method of claim 3,
Wherein the first and second metal salts are different metal salts and at least one of Sn, Cu, Zn, Ni, Al, Ti, V, Cr, Mn, Fe, Co, Ga, Ge, As, Zr, Nb, Mo, Wherein at least one metal salt selected from the group consisting of Pd, Ag, Cd, In, Sb, Te, Hf, Ta, W, Re, Os, Ir, Pt, Au, .
6. The method of claim 5,
Wherein the first and second metal salts are selected from two or more metal salts of a metal having a standard reduction potential difference of 0.029 V or more and 1.0496 V or less.
The method of claim 3,
Wherein the acid is selected from the group consisting of sulfuric acid, hydrochloric acid, methanesulfonic acid (MSA), nitric acid, boric acid, acetic acid, organic sulfuric acid, citric acid, formic acid, ascorbic acid, hydrofluoric acid, phosphoric acid, lactic acid, amino acid and hypochlorous acid Gt;
The method of claim 3,
Wherein the additive is selected from polyoxyethylene lauryl ether (POELE), a plating flatting agent (smoothing agent), an accelerator, an inhibitor, a defoaming agent, a polishing agent, and an oxidation inhibitor.
The method according to claim 1,
The forming of the amorphous metal plating film is a step of forming at least two layers,
Wherein a first plating layer is formed in the first application period and a second plating layer is formed in the second application period.

10. The method of claim 9,
When the amorphous metal plating film is laminated with two layers including a first plating layer and a second plating layer,
The first plating layer and the second plating layer may be formed so that the first time t ₁ is 0 <t ₁ ≤ 10 (min) and the second time t ₂ is 0 <t ₂ ≤ 200 (min) Is formed in the range of 10 nm to 150 nm, respectively.
The method according to claim 1,
Wherein the amorphous metal plating film has a total thickness ranging from 0.6 nm to 300 mu m.
A bonding material comprising at least two or more amorphous metal plating films containing at least two metals having a difference in standard reduction potential of not less than 0.029 V and not more than 1.0496 V and which is solidified after melting to bond the materials to be bonded,
Wherein the amorphous metal plating film has an exothermic reaction during the initial melting and the temperature (T _m1 ) at which the amorphous metal plating film is initially melted is lower than the temperature (T _m2 ) at which the amorphous metal plating film is melted after the solidification.
13. The method of claim 12,
Wherein the amorphous metal plating film includes a first plating layer and a second plating layer, and each of the plating layers has a thickness of 10 nm to 150 nm.
13. The method of claim 12,
The metal may be selected from the group consisting of Sn, Cu, Zn, Ni, Al, Ti, V, Cr, Mn, Fe, Co, Ga, Ge, As, Zr, Nb, Mo, Ru, Rh, Pd, Ag, At least one metal selected from the group consisting of Te, Hf, Ta, W, Re, Os, Ir, Pt, Au, Tl, Pb and Bi.
13. The method of claim 12,
Wherein the total thickness of the amorphous metal plating film is 0.6 nm to 300 占 퐉.
13. The method of claim 12,
Wherein the amorphous metal plating film has a structure in which the first plating layer and the second plating layer are repeatedly laminated six or more times.
13. The method of claim 12,
Wherein the amorphous metal plating film has a temperature (T _m1 ) at which the amorphous metal plating film melts at the initial melting is lower than a melting point (T _ma ) of the entire bulk composition constituting the amorphous metal plating film.
13. The method of claim 12,
Wherein the bonding material is a material for low-temperature bonding in which the amorphous metal plating film bonds the materials to be bonded by an exothermic reaction caused by a change in crystal phase from amorphous to crystalline.

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