KR101924130B1 - Multilayered Composite Pellets and Method for fabricating the same and Method for Bonding Intermetallic Substrates using the same - Google Patents

Abstract

The present invention relates to a multi-layered composite pellet for producing an interfacial bonding metal-based high-energy material / interfacial metal-based multi-layered pellet, placing it between metal substrates and performing interfacial bonding by ignition and combustion, A first bonding material layer for metal interface bonding, a second bonding material layer for metal interface bonding, a high energy material layer between the first bonding material layer and the second bonding material layer, And the first and second bonding material layers are melted by thermal energy generated during ignition and combustion of the high energy material composite to be bonded to the metal interface.

Description

TECHNICAL FIELD [0001] The present invention relates to a multilayered composite pellet, a method for manufacturing the same, and a method for fabricating the same,

More particularly, the present invention relates to a metal-to-metal interface bonding technique, and more particularly, to a multi-layer structure pellet based on a metal for interfacial bonding, a metal for high energy material / interfacial bonding, and a method for interfacial bonding by igniting and burning A multi-layered composite pellet, a method for producing the same, and a method for joining metal interfaces using the same.

The general interface bonding process is performed by various methods such as anodic bonding, direct bonding, solder bonding, and adhesive bonding.

In such a joining step, the joining characteristics such as the bonding strength and the airtightness are changed according to variables such as temperature, pressure, time, and kind of substrate.

In particular, in the case of soldering and brazing, the solder melts in a closed environment at high temperature and forms a compound between the solder and the bonded substrate, The bonding state is sensitively changed.

Specifically, by controlling the temperature of the bonding region appropriately, the residual stress can be reduced in the case of multilayer bonding, but in the case of temperature-sensitive substrates, the bonding strength may be lowered due to the range of high temperature heat applied, It is possible to cause the phenomenon to be weakened.

In addition, when a low pressure is applied to the joint, the actual contact area of the joint decreases, and the joint is not air tight, resulting in a decrease in joint strength.

Thus, most of the interfacial bonding methods are performed inside a closed system and require a relatively complicated process based on very high temperature and pressure.

Therefore, it is required to develop a heat source and to develop a new joining technique which enables rapid heating locally without needing to raise the temperature of the entire system.

Korean Patent Publication No. 10-2016-0067258 Korean Patent Publication No. 10-2016-0027452

The present invention solves the problem of the prior art interfacial bonding process, in which multi-layered pellets based on metal for interfacial bonding / high energy material / interfacial bonding are prepared, placed between metal substrates, ignited and burnt Layer composite pellet for performing interfacial bonding, a method for producing the same, and a method for joining metal interfaces using the same.

The present invention relates to a multi-layered composite pellet for producing solder / high energy material / solder-based multi-layer structure pellets, placing them between metal substrates and igniting and burning them to perform interface bonding of metal substrates, a method for manufacturing the same, The purpose of the method is to provide.

The present invention is based on the assumption that the fuel material is composed of a high energy material and is composed of [Al (Al) and iron oxide (Fe ₂ O ₃ ) -based micro- and nano-scale particles as an oxidizer) Layer structure pellets for producing solder / high energy material / solder-based multi-layer structure pellets by adding [Ni (Ni) nanoparticles] as an improving material for bonding strength, and a method for manufacturing the same The present invention provides a method of interfacial bonding.

The present invention relates to a process for producing a multilayer structure pellet based on a solder / high energy material / solder, placing pellets for bonding between copper (Cu) metal substrates and igniting and burning them using a hot- Layer composite pellet for performing interfacial bonding, a method for producing the same, and a method for joining metal interfaces using the same.

The present invention applies solder material and energetic materials (EM) composite pellets in an open system at room temperature to locally heat the solder by igniting and burning the pellets at the interface between metal interfaces, Layered composite pellets in which strong bonding can be achieved by applying pressure to a substrate, a method for manufacturing the composite pellet, and a method for joining metal interfaces using the same.

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.

According to another aspect of the present invention, there is provided a multi-layered composite pellet including a first bonding material layer for metal interface bonding, a second bonding material layer for metal interface bonding, Wherein the first and second bonding material layers and the high energy material composite comprise a first bonding material layer, a high energy material composite, a second bonding material layer, and a second bonding material layer, And the material layer are layered in order and pressure-molded in a circular shape, and the bonding pellet is subjected to ignition and combustion reaction using a tungsten wire-based resistance heat to generate heat energy generated during ignition and combustion of the high- The first and second bonding material layers are melted and bonded to the metal interface, The ignition pellet further comprises an ignition pellet which generates a high temperature flame by initial ignition using resistance heat based on tungsten wires to ignite and burn the bonding pellet .

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The first and second bonding material layers are solder powder.

The high energy material composite is characterized in that aluminum (Al) is used as a fuel material and iron oxide (Fe ₂ O ₃ ) is used as an oxidizer material.

The high-energy material composite is characterized in that micro-scale aluminum (Al) particles and nanoscale aluminum (Al) particles are mixed with a fuel material.

The high energy material composite further includes nickel (Ni) nanoparticles for controlling combustion and explosion characteristics and improving bonding strength.

The high energy material composite is characterized in that the aluminum nanoparticles (Al NP), the aluminum microparticles (Al MP), the nickel nanoparticles (Ni NP) and the iron oxide (Fe ₂ O ₃ ) NP: Fe ₂ O ₃ NP = 23: 31: 15: 31 wt%.

During the ignition and combustion of the high-energy material composite, the aluminum nanoparticles (Al NP) react first to generate heat energy by the exothermic reaction, and then continuously dissolve aluminum microparticles (Al MP) Thereby controlling the combustion speed and the combustion time.

According to another aspect of the present invention, there is provided a method of manufacturing a multi-layered composite pellet, comprising: preparing a high energy material composite powder by mixing a fuel and an oxidizer; A step of laminating a material powder, a powder of a high energy material composite, and a powder of a second joint material for metal interface bonding in this order; a bonding step for forming a metal interface between the first and second bonding material layers, A method of manufacturing a high purity bell-pellet comprising the steps of: preparing a boding pellet, wherein ignition and combustion reactions are induced using a tungsten wire-based resistance heat, The first and second bonding material layers are dissolved by thermal energy to be bonded to the metal interface, and the first and second bonding material layers are not included, An ignition pellet consisting solely of a material complex is produced so that an ignition pellet generates a high temperature flame by initial ignition using resistance heat based on tungsten wires to ignite the bonding pellet And burning.

Here, the first and second bonding materials are solder powder, and aluminum (Al) is used as a fuel material and iron oxide (Fe ₂ O ₃ ) is used as an oxidizer material.

The high-energy material composite is characterized in that micro-scale aluminum (Al) particles and nanoscale aluminum (Al) particles are mixed with a fuel material.

The high energy material composite further includes nickel (Ni) nanoparticles for controlling combustion and explosion characteristics and improving bonding strength.

The high energy material composite is characterized in that the aluminum nanoparticles (Al NP), the aluminum microparticles (Al MP), the nickel nanoparticles (Ni NP) and the iron oxide (Fe ₂ O ₃ ) NP: Fe ₂ O ₃ NP = 23: 31: 15: 31 wt%.

According to another aspect of the present invention, there is provided a method of joining metal interfaces using a multi-layered composite pellet, comprising the steps of: preparing a high energy material composite powder by mixing a fuel and an oxidizer; , A high energy material composite powder, and a second bonding material powder for metal interface bonding in this order; a step of forming a high energy material composite between the first and second bonding material layers by pressure molding; A method of manufacturing a bonding pellet for interfacial bonding, comprising the steps of: placing a bonding pellet between a metal substrate and a metal substrate, heat energy generated during ignition and combustion of the high energy material composite, And the second bonding material layer is dissolved and bonded to the metal interface, wherein the first and second bonding material layers are dissolved to form a An ignition pellet consisting solely of the high energy material composite without the first and second layers of bonding material is prepared and the ignition pellet is formed using tungsten wire based resistance heat The initial ignition generates a high temperature flame to ignite and burn the bonding pellet, and the ignition of the high energy material composite is performed by ignition pellets and bonding pellets on a metal substrate and a metal substrate And inducing the ignition and combustion reaction using the tungsten wire-based resistance heat, and simultaneously pressing the two metal substrates at room temperature.

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In addition, micro-scale aluminum (Al) particles and nanoscale aluminum (Al) particles are mixed with fuel material of the high energy material composite, and aluminum nanoparticles Al NP) reacts first to generate thermal energy by exothermic reaction and then continuously dissolves aluminum microparticles (Al MP) and induces an additional exothermic reaction to control the burning rate and the burning time.

In the step of melting the first and second bonding material layers and bonding the first and second bonding material layers to the metal interface, the first and second bonding material layers are melted by the heat energy generated during ignition and combustion of the high energy material composite, And solidified to be fixed to the interface of the metal substrate and a diffusion bonding layer is formed at the interface of the metal substrate.

The multi-layered composite pellet according to the present invention, the method for manufacturing the same, and the method for joining metal interfaces using the multi-layered composite pellet have the following effects.

First, a new type of interfacial bonding between metals is provided by applying a high-energy material having a high reactivity upon ignition to a part where interfacial bonding is required, thereby serving as a heating element capable of melting the bonding metal.

Second, the multi-layered pellets based on metal for interfacial bonding / metal / interfacial bonding for interfacial bonding can be fabricated, placed between metal substrates, ignited and burnt to effectively perform interfacial bonding.

Third, it is possible to quickly heat locally without increasing the temperature of the entire system including the interface.

Fourth, complex heating devices required for interfacial bonding can be simplified, and local fine bonding can be realized in a complicated structure.

Fifth, new bonding technology and process applying high energy materials as interfacial bonding heat sources will be applied to various thermo - electric civilian technology applications.

Sixth, the interfacial bonding process can be performed only by locally heating the periphery of the bonding region without heating the whole environment by preparing solder / high energy material / solder-based multilayer structure pellets for metal interface bonding and installing them between metal substrates .

Seventh, in an open system at room temperature, solder material and energetic materials (EM) composite pellets are applied to melt the solder locally by ignition and combustion of pellets at the interface between metal interfaces, A strong bonding can be achieved.

FIG. 1A is a view showing a process of manufacturing a multi-layered composite pellet according to the present invention and a process of bonding a metal interface
1B is a flow chart illustrating the process of preparing a multi-layered composite pellet according to the present invention and a process of joining metal interfaces;
FIGS. 2A to 2G are schematic views showing FE-SEM and EDX measurement results of the composite material according to the present invention
Figure 3 is an image of combustion and explosion characteristics of a composite pellet according to the present invention;
FIG. 4 is a graph showing the relationship between the Al particle size and the exothermic characteristic of the composite powder according to the addition of Ni
Figure 5a is a snapshot analysis of the composite pellet with various amounts of oxidant material added by tungsten wire resistance thermal ignition
FIG. 5B is a graph showing changes in the burn rate and total burning time of the composite pellets to which various amounts of the oxidizing agent are added.
6A and 6B are graphs showing the DSC analysis of the composite powder according to the content of the oxidizing agent and the comparative analysis result of the total heat energy
FIGS. 7A and 7B show XRD analysis results of the composite powder before thermal ignition reaction, and XRD analysis results of products after the combustion reaction
Fig. 8 is a FE-SEM image of (a) FE / SEM image of Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP cross section layer, (b) FE-SEM image of a multilayer structure pellet of solder / ) FE-SEM image of the solder / EM interface
FIG. 9 is a graph showing the results of (a) photographs of the interface bonding process and the actual device, (b) photographs of solder / EM / solder multilayer structure pellets after ignition and combustion bonded copper substrates, (c) initial ignition of pellets by tungsten wire igniter, (D) Cross-sectional SEM image of the bonded body after interfacial bonding
10 shows the results of interfacial bonding of two copper substrates using pure solder pellets and solder / high energy material / solder (EM / solder) multi-layered composite pellets, respectively.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of a multilayered composite pellet according to the present invention, a method for producing the same, and a method for joining metal interfaces using the same will be described in detail.

The characteristics and advantages of the multi-layered composite pellet according to the present invention, the method for producing the same, and the method for joining metal interfaces using the same will be apparent from the following detailed description of each embodiment.

FIG. 1A is a view showing a process of preparing a multi-layered composite pellet according to the present invention and a process of joining metal interfaces, and FIG. 1B is a flowchart showing a process of manufacturing a multi-layered composite pellet and bonding the metal interfaces.

A high-energy material (EM) is a composite material consisting of a fuel material and an oxidizer. It is a mixture of energy and heat energy in a very short period of time. And has been attracting attention in various fields of various thermal engineering bases and applications as igniters, propellants and explosives.

In the present invention, a high-energy material having a high reactivity upon ignition is applied to a portion where interfacial bonding is required to serve as a heating element capable of melting the solder.

That is, the present invention relates to a bonding technique capable of making interfacial bonding by preparing a functional high-energy material and using them as a medium for heat generation and solder dissolution.

When a high energy material is used as a heat source for interfacial bonding in this way,

(i) it is possible to quickly heat locally without increasing the temperature of the entire system including the interface,

(ii) the complex heating device required for general interface bonding can be simplified,

(iii) There are a variety of advantages that can achieve localized micro junctions in complex structures.

Therefore, new bonding technology and process using such high energy materials as interfacial bonding heat source can maximize the application range of various thermo - electric civilian technologies.

The present invention relates to a method for manufacturing a solder paste for solder joints, a solder paste for high-energy material / solder-based solder, and a method for manufacturing the solder paste, It is.

In the embodiment of the present invention, iron (Fe ₂ O ₃ ) -based micro- and nano-scale particles are used as a fuel material for aluminum and an oxidizer material for a high-energy material.

Nickel (Ni) nanoparticles are added as materials for controlling combustion and explosion characteristics and bonding strength, and they are made into solder / high-energy material / solder-based multi-layer structure pellets by a molding process, , And the metal substrate is bonded to the metal substrate by igniting and burning the metal pellet using a hot-wire.

In order to observe the ignition, combustion, and bonding characteristics of high-energy material / solder-based composite pellets suitable for such interfacial bonding, a high speed camera, a pressure cell, And was measured using a differential scanning calorimeter, an X-ray diffractometer, and a tensile tester.

More specifically, the multi-layered composite pellet according to the present invention mainly includes a first bonding material layer for metal interface bonding, a second bonding material layer for metal interface bonding, and a second bonding material layer for bonding between the first bonding material layer and the second bonding material layer High energy material complexes.

The first and second bonding material layers are melted and bonded to the metal interface by thermal energy generated during ignition and combustion of the high energy material composite.

Here, the first and second bonding material layers and the high energy material composite are laminated in the order of the first bonding material layer, the high energy material composite, and the second bonding material layer and pressure-molded in a circular shape, .

The high-energy material composite is characterized in that aluminum (Al) is used as a fuel material, iron oxide (Fe ₂ O ₃ ) is used as an oxidizer material, combustion and explosion characteristics are controlled, (Ni) nanoparticles.

The high energy material composite may be prepared by mixing micro-scale aluminum (Al) particles with nanoscale aluminum (Al) particles as a fuel material, and when the high energy material composite is ignited and burned , Aluminum nanoparticles (Al NP) react first to generate thermal energy by an exothermic reaction, and then continuously dissolve aluminum microparticles (Al MP) and induce an additional exothermic reaction to control the burning rate and the burning time.

And the manufacturing method of the multi-layered composite pellets, as shown in Figure 1b as Figure 1a, an aluminum (Al) nanoparticles (nanoparticle, NP) / microparticles (microparticle, MP), nickel (Ni) nanoparticles, iron oxide (Fe ₂ O ₃ ) The nanoparticles are mixed in an ethanol solution using ultrasonic energy (S101).

Next, the mixed high-energy material composite powder is placed in a convection type dryer and heated to dry the ethanol solution to finally produce a high energy material (EM) composite powder for interfacial bonding (S102)

EMs and manufactured _{(i.e., Al / Fe 2 O 3 /} Ni complexes) and laminating the powder and the Solder (SAC305, Sn-30Ag- 0.5Cu) powder, in order to Solder powder / powder EMs / Solder powder sequence. (S103)

Subsequently, pressure-molding is performed to produce a multi-layered disk-shaped pellet based on a solder / EM / solder (S104)

As shown in FIGS. 1A and 1B, the manufactured solder / EM / solder composite pellets are placed between copper substrates, and the ignition and combustion reactions are induced by the tungsten wires The two copper substrates are pressed at room temperature (S105)

Specifically, in the embodiment of the present invention, aluminum nanoparticles (Al, Nano Technology) having an average diameter of ~ 100 nm and aluminum micro particles (Al, Metal Player Co. Ltd) having an average diameter of ~ Mix and use.

Iron oxide (Fe ₂ O ₃ , Sigma Aldrich) having an average diameter of 90 nm was used as the metal oxidizer material, and nickel nanoparticles (Ni, Nano Technology) having an average diameter of ~ 55 nm were further used as fuel for supplementary heating do.

FIG. 1A shows a manufacturing process of a multilayer pellet based on a solder / high energy material / solder (solder / EM / solder). A high energy composite powder is produced using aluminum, iron oxide, and nickel particles, / High-energy material / solder-based multi-layer composite pellets, placing the pellets between the copper metal substrates and igniting and burning them using tungsten wire-based resistive heat to achieve interfacial bonding.

(a) shows the manufacturing process of EM powder, (b) shows the production of solder / EM / solder based multilayer structure pellet through EM powder and solder powder by compression molding process, It is the step of implementing interface bonding between substrates.

First, the nanoparticles of aluminum (Al) nanoparticles (NP) / microparticles (MP), nickel (Ni) nanoparticles and iron oxide (Fe ₂ O ₃ ) ₂ O ₃ NP = 23: 31: 15: 31 wt% in an ethanol solution for 30 minutes using ultrasonic energy (ultrasonic output = 170 W, ultrasonic frequency = 40 kHz).

The mixing ratio of Al NP: Al MP: Ni NP: Fe ₂ O ₃ NP = 23: 31: 15: 31 wt% was experimentally determined as a ratio showing the most efficient combustion and heating characteristics as a result of various combustion tests.

The high energy material composite powder prepared by mixing the above components is placed in a convection type dryer and heated at 80 ° C. for 30 minutes to dry the ethanol solution to finally prepare a high energy material (EM) composite powder for interfacial bonding.

In order to observe the reaction heat during the ignition of the thus prepared Al / Fe ₂ O ₃ / Ni powder, a differential scanning calorimeter (DSC) method was used in a range of 30 ° C. to 1000 ° C. at a heating rate of 10 ° C./min in a nitrogen atmosphere. ; Setaram, Model No. LABSYS evo) was used to measure the amount of generated heat energy according to the temperature.

Producing a EMs _{(i.e., Al / Fe 2 O 3 /} Ni complex) Solder powder having an average diameter and ~ 70㎛ (SAC305, Sn-30Ag -0.5Cu) , respectively the EMs powder 40 mg and 30 mg Solder powder Solder powder Powder, EMs powder, and solder powder were sequentially stacked in this order and molded at a pressure of 300 MPa to prepare a multi-layered disk-shaped pellet based on a solder / EM / solder having a diameter of 7 mm and a height of about 1 mm.

The fracture profiles of the solder / EM / solder composite pellets were observed using FE-SEM (Hitachi, Model No. S4700).

In order to observe the ignition and explosion reaction of the prepared solder / EM / Solder composite pellets in atmospheric air, the film was photographed at a frame rate of 30 kHz using a high speed camera (FASTCAM SA3 120K).

The high-speed camera used has a maximum frame rate of 1200000 fps, a minimum frame rate of 60 fps, a sensor size of 17.4 mm x 17.4 mm, a CMOS image sensor, Pixel size) 17 ㎛ x 17 ㎛, operating voltage and current conditions are DC 22-32V 100VA, AC 100-240V 10-60 Hz, 60 VA respectively.

The prepared solder / EM / Solder composite pellets were placed between copper substrates, and the ignition and combustion reactions were induced by tungsten wires. The two copper substrates were pressed at room temperature, and they were measured using a high speed camera (FASTCAM SA3 120K) The frame rate was 30 kHz.

The final bonded substrate was cut and the fracture surface was observed using FE-SEM (Hitachi, Model No. S4700). The strain rate was 10 mm using a tensile strength tester (LRXPlus 5kN, Lloyd Instruments Ltd.) / min and the mechanical strength of the bonded metal substrate was measured.

FIGS. 2A to 2G are schematic views showing FE-SEM and EDX measurement results of the composite material according to the present invention.

2B is an Al micropowder (Al MP), FIG. 2C is a Ni nanopowder (Ni NP), FIG. 2D is a Fe ₂ O ₃ nanopowder (Fe ₂ O ₃ NP) Figure 2e is Al NP / Al MP / Ni NP / Fe ₂ O ₃ low magnification image of the NP composite powder, Fig. 2f is Al NP / Al MP / Ni NP / Fe ₂ O ₃ the high magnification image of the NP composite particles, FIG. 2g is Al The result of EDX analysis of NP / Al MP / Ni NP / Fe ₂ O ₃ NP powder is shown in Fig.

First, the fuel metal material used for interfacial bonding is spherical aluminum nanoparticles (Al NP) having an average diameter of about 100 nm, spherical aluminum microparticles (Al MP) having an average diameter of about 8 m, nm < / RTI > (Ni NP).

Spherical iron oxide nanoparticles (Fe ₂ O ₃ NP) having an average diameter of about 90 nm were used as the metal oxidizer material.

In Fig. 2e, it is observed that Al NP / Ni NP / Fe ₂ O ₃ NP powders are strongly adhered between Al NP, Ni NP and Fe ₂ O ₃ NPs on the surface of Al MP having an average diameter of ~ 8 μm .

Also, as can be seen in FIG. 2f, it was observed that Al NP, Ni NP and Fe ₂ O ₃ NPs were relatively uniformly dispersed and mixed in the nanoscale in the Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP complex can do. The results of the EDX analysis of FIG. 2g also confirm that Al NP, Ni NP and Fe ₂ O ₃ NP are relatively uniformly distributed in the nanoscale region.

The combustion and explosion characteristics of Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP powder, which is the final composition prepared by the present invention, Ni NP / Fe ₂ O ₃ NP, Al NP / Ni NP / Fe ₂ O ₃ NP, and Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP powder powders were ignited in air, respectively, And explosion characteristics were observed.

In this case, ignition and explosion reactions of Al MP / Ni NP / Fe ₂ O ₃ NP, Al NP / Ni NP / Fe ₂ O ₃ NP, Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP powder in air Was observed in real time using a high-speed camera. Finally, the burn rate and the total burning time were experimentally determined by analyzing the explosion reaction video and still image.

Al NP / Ni NP / Fe ₂ O ₃ NP, Al NP / Ni NP / Fe ₂ O ₃ NP, Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP powder powders were ignited by tungsten wire resistance heat, The result of the still image in which the explosion flame propagates is shown in Fig.

FIG. 3 is a graph showing the results of a comparison of the pore size distribution of AlP / Ni NP / Fe ₂ O ₃ NP, Al NP / Ni NP / Fe ₂ O ₃ NP and Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP pellets by tungsten resistance heat ray ignition Combustion and explosion characteristics of high-speed camera shooting and still image analysis.

As can be seen from FIG. 3, in the case of Al NP / Ni NP / Fe ₂ O ₃ NP and Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP powder, the combustion and explosion reactions were ignited by tungsten wires. In the case of Al MP / Ni NP / Fe ₂ O ₃ NP powder without Al NP, initial ignition did not occur at all.

Generally, in a high-energy composite material, Al nanoparticles (Al NP) powder is locally ignited by tungsten wire resistance heat, and at the same time, an initially generated local hot flame is delivered in series to adjacent high-energy materials Eventually resulting in macroscopic combustion and explosion.

The reason why the ignition and combustion reaction did not occur at all in the Al MP / Ni NP / Fe ₂ O ₃ NP composite powder is that Al NP having high reactivity to the external energy applied is not contained and Al MP requires very large external energy to be ignited.

The activation energy of the Ni nanoparticles of 800 nm on average and Al microparticles of 20 μm on average is 103 kJ / mol and the ignition temperature is about 720 ° C, as reported by Hunt (2005) In the case of Al nanoparticles having an average particle size of 80 nm, the activation energy is about 21 kJ / mol, and the ignition temperature is very low at 376 ° C. (EM Hunt and ML Pantoya, Journal of Applied Physics 98: 034909 (2005)).

Based on the snapshot analysis of FIG. 3, the burn rate and total burning time of the high energy complex material were obtained.

Here, the burn rate of the high energy composite material was calculated by dividing the total length of the high energy material sample by the total time it takes for the flame to reach the other end starting from one end of the sample.

If the ignition burn rate in the case of _{Al NP / Ni NP / Fe 2} O 3 NP 0.42 m / s, Al NP / Al MP / Ni NP / Fe 2 O 3 NP of tungsten wire resistance column appeared to 0.084 m / s was, the total burning time was found in the case of when the NP Al / Ni NP / Fe ₂ O ₃ NP 120 ms, Al NP / NP Ni / Fe ₂ O ₃ NP 500 ms value.

This is because Al NP reacts preferentially in the Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP complex to generate thermal energy by exothermic reaction and then continuously dissolves Al MP and induces additional exothermic reaction, / 5 and the combustion time was increased to about 4 times.

In order to effectively dissolve the solder powder in the present invention by using the thermal energy generated during the ignition and combustion of the high energy composite material, sufficient heat energy is maintained for a suitable time rather than a short time exothermic reaction It is effective to use a heating element.

Therefore, in the present invention, the Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP composite having a low burning rate and a sufficiently long total burning time was finally selected as the composition of the high energy composite material for heat generation and then applied to the metal interface bonding process .

FIG. 4 is a graph showing the effect of aluminum particle size on the total reaction heat energy in the heat source composite for metal interface bonding (i.e., Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP) (DSC). ≪ / RTI >

FIG. 4 shows (a) DSC absolute calorific value analysis of the composite powder according to Al particle size and Ni addition, (b) DSC relative calorific value analysis; (c) Al MP, (d) Al NP, (e) DSC analysis of Al MP / Al NP composite powder; (f) a graph showing the total reaction heat of the exothermic reaction.

As shown in FIGS. 4A and 4B, DSC measurement of Al MP / Ni NP and Al NP / Ni NP composite showed that endothermic reactions were commonly observed at temperatures of about 650 ° C in both samples, It is judged to be the melting point of the substance.

However, no peak related to the endothermic reaction was observed in the Al MP / Al NP / Ni NP composite.

In the case of Al NP / Ni NP composite powder, a strong exothermic reaction was clearly observed in the temperature range of about 500 ~ 600 ° C and in the temperature range of 550 ~ 570 ° C in Al MP / Al NP / Ni NP composite powder .

However, in the case of the Al MP / Ni NP composite powder, it can be confirmed that no definite exothermic reaction occurs. This is considered to be the result of an exothermic reaction involving the synthesis of an intermetallic compound of Al and Ni at the same time that the Ni powder formed by the oxidation of the Ni powder causes the spontaneous oxidation reaction of the Al powder serving as the oxidant for the Al particles.

As shown in the DSC analysis of FIG. 4C, Al MP started exothermic reaction at about 550 ° C. to form Al ₂ O ₃ , and unreacted Al particles were observed to melt at about 640 ° C.

As shown in FIG. 4D, in the case of Al NP, the exothermic reaction starts at about 550 ° C., and the specific surface area is larger than that of Al MP to form relatively more Al ₂ O _3. As a result, It can be observed that the absolute value of the endothermic reaction related to the melting behavior at the temperature is very low.

In the case of the mixture of Al MP and Al NP, a relatively weak endothermic reaction occurs at about 650 ° C after the start of the rapid exothermic reaction at about 500 ° C.

If the ignition and combustion energy externally applied are low, the oxidation reaction does not occur in the central region of Al MP, and unreacted Al remains.

However, in the mixture of Al MP and Al NP, the unreacted core material of Al MP reacts exothermically due to the high reaction heat generated by the active reaction of Al NP.

The low endothermic reaction is considered to be the result of the absolute amount of pure Al being lowered as most Al materials change to Al ₂ O ₃ phase.

However, as shown in FIGS. 4A and 4B, the rapid reaction heat in the case of Al MP / Al NP / Ni NP is considered to be a rapid reaction due to the complexity of the interface energy depending on the particle size.

Based on the area calculation of various DSC calorific value data, the total heat of the exothermic reaction of Al MP / Ni NP, Al NP / Ni NP and Al MP / Al NP / Ni NP is calculated The results are shown.

The total exotherm energy of Al NP / Ni NP was relatively low and the total exotherm energy of Al NP / Ni NP was 1,800 J / g. / Al NP / Ni NP showed very high total exotherm energy of about 3,000 J / g.

In the case of Al MP / Al NP / Ni NP, unlike the case of ignition of Al MP / Ni NP and Al NP / Ni NP composite powders, It was judged that it was able to show a high heat of combustion finally.

Fe ₂ O ₃ NP, an oxidizing agent, is added to the Al NP / Al MP / Ni NP composite powders as a heat source material at the rate of 10-70 wt%, and the combustion and explosion characteristics of the composite pellets The results are shown in FIGS. 5A and 5B.

Snapshot analysis (Fig. 5a) based on high-speed camera shooting of Al NP / Al MP / Ni NP composite pellets with various amounts of oxidizing agent (Fe ₂ O ₃ NP) added by tungsten wire resistance thermal ignition, burn rate, And the total burning time (FIG. 5B).

As shown in Figure 5a, the mixture of various oxidizing agent ratio Al NP / Al MP / Ni NP / Fe 2 O 3 NP (30, 40, 50, 60, 70 wt%, where the values in parentheses are Fe ₂ relative to the total mass O ₃ ). In the composite pellets, the ignition and explosion reactions were successfully induced by the resistance heat of the tungsten wire. However, in the composite pellets of Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP No ignition and explosion reactions occurred at all.

This suggests that the addition of more than a certain amount of oxidizing agent to the Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP pellets may inhibit the initiation of ignition and explosion reactions due to the insufficient oxygen supply required for the aluminothermic reaction it means.

Figure 5 (b) is a graphical representation of Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP (10,20,30,40,50,60,70 wt%) composite pellets based on still image analysis based on high- The burn rate and total burning time were calculated.

The burning rates of Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP (30, 40, 50, 60, 70 wt%) composite pellets were about 1.05, 2.12, 2.23, 2.37 and 2.68 m / s And the total combustion time decreased to 366, 333, 276, 250 and 231 ms, respectively.

In other words, when the amount of Fe ₂ O ₃ NP as the oxidizing agent is increased in the Al NP / Al MP / Ni NP complex, it means that the burning rate gradually increases and the total burning time decreases during ignition.

6A and 6B are graphs of DSC analysis and total exotherm energy of Al MP / Al NP / Ni NP composite powder according to the content of oxidizing agent (Fe ₂ O ₃ NP).

6A and 6B show the content of iron oxide nanoparticles as oxidizing agents in aluminum microparticles (Al MP), aluminum nanoparticles (Al NP), nickel nanoparticles (Ni NP) and iron oxide nanoparticles (Fe ₂ O ₃ NP) (DSC) measurement results and total heat emission amount of exothermic reaction in order to observe the effect on the total reaction heat energy upon ignition change.

FIG Al MP / Al NP / Ni NP / Fe 2 O 3 NP (30, 40, 50 wt%) composite powder as shown in 6a has been common to make the exothermic reaction at a temperature of about 550 ~ 650 ℃.

On the basis of this, the total heat energy emission amount by the exothermic reaction of Al MP / Al NP / Ni NP / Fe ₂ O ₃ NP (30, 40, 50 wt%) composite powder was calculated in FIG.

The energy per unit mass due to the exothermic reaction of Al MP / Al NP / Ni NP / Fe ₂ O ₃ (30, 40, 50 wt%) composite powders with increasing Fe ₂ O ₃ content was about -953 J / g _{@Fe 2 O 3 = 30wt%,} -1314 J / g @ Fe 2 O 3 = 40wt%, -1214 J / g @ Fe 2 O 3 = 50wt% as Fe ₂ O ₃ content of the total heat generation by 30-40wt% increase the amount of energy while the Fe ₂ O ₃ content of about 50wt% tended to slightly decrease the total amount of heat energy.

This is that _{2Al + Fe 2 O 3 → Al} 2 O 3 + 2 Fe, ΔH o 298 = -850 kJ / mol in the exothermic reaction of the optimum content of oxidant Fe ₂ O ₃ required for the oxidation reaction of the Al of about 40wt% It is also the result of suggestion.

Therefore, in order to effectively use the solder powder for metal interface bonding in melting and bonding, it is necessary to maintain a high heat of reaction for a sufficient long time. Therefore, it is necessary to use Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP wt%) composite powder is applied to the metal interface bonding process in the embodiment of the present invention.

FIG. 7 is a graph showing the results of XRD analysis of (b) thermal ignition reaction and (b) XRD analysis of products after combustion reaction of Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP powder.

FIGS. 7A and 7B show X-ray diffraction patterns (XRD) of aluminum nanoparticles, aluminum microparticles, nickel nanoparticles, and iron oxide nanoparticle composite powders before and after exothermic reaction by ignition for ignition.

As shown in FIG. 7A, in the case of Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP powder before the combustion reaction, a strong signal due to X-ray diffraction of all raw materials Al, Ni and Fe ₂ O ₃ Respectively.

However, as shown in FIG. 7B, X-ray diffraction signals on Al ₂ O ₃ , Fe, AlNi ₃ and Al ₂ NiO ₄ produced after the exothermic reaction of Al / Ni / Fe ₂ O ₃ were observed after combustion.

In the case of the Al / Fe ₂ O ₃ reaction, a phase change of 2Al + Fe ₂ O ₃ → Al ₂ O ₃ + 2Fe and ΔH ^o ₂₉₈ = -850 kJ / mol occurs and in the Al / Ni reaction, 3Al + 2Ni → Al ₃ Ni _{2 , and} ΔH ^o ₂₉₈ = -322.5 kJ / mol.

Therefore, it is expected that Al ₃ Ni ₂ phase will be formed by remaining Al and Ni after the combustion reaction of Al / Ni / Fe ₂ O ₃ composite. However, since the content of remaining Al is relatively smaller than that of Ni, AlNi ₃ phase and Al ₂ O ₃ reacted to form a complex product phase of Al ₂ NiO ₄ .

In general, the alloys of Al and Ni have relatively low density, high strength, corrosion resistance, and heat resistance as compared with other metal composites.

Among the intermetallic compounds of Al and Ni, AlNi having a high melting point and AlNi ₃ having a characteristic of increasing a yield stress with increasing temperature are alloys capable of improving durability and heat resistance due to thermal fatigue in a high temperature environment.

Therefore, in the embodiment of the present invention, it is possible to utilize the hetero-alloy characteristics of Al and Ni to improve the metal interface bonding property.

8 (a) is an FE-SEM image of an Al NP / Al MP / Ni NP / Fe ₂ O ₃ NP cross-sectional layer as an enlarged section of the EM portion of the multilayer structure produced by the press- FE-SEM image of the solder / EM / solder composite multi-layer structure pellet section, and (c) FE-SEM image of the solder / EM interface.

FE-SEM analysis was carried out to confirm the size, shape and thickness of the solder / EM / solder composite multilayer structure pellet manufactured in the example of the present invention.

In FIG. 8A, it can be seen that Al fuel material nanoparticles, Fe ₂ O ₃ metal oxide nanoparticles, and Ni nanoparticles having a spherical shape of about 100 nm diameter are strongly adhered to each other.

FIG. 8B is an FE-SEM photograph of the fracture surface of the multi-layered structure of the solder / EM / solder composite pellet. As shown in the plan view, the thickness of the solder layer is about 300 μm, Which is about ~ 900 [mu] m, which is about three times the thickness of the solder layer.

Where the layer thickness of solder and high energy material is relatively easily adjustable depending on the amount of solder and high energy material loaded.

As shown in FIG. 8C, it can be observed that the interface of the solder / high energy material produced is strongly contact with the surface of the solder particles, which are relatively large particles, while finely filling the high-energy material.

In order to test the applicability of the solder / EM / solder composite multi-layered pellet manufactured according to the embodiment of the present invention as a heat source for metal interface bonding, pellets were placed between copper substrates, and pellet ignition was performed using a tungsten wire igniter The result of the compression bonding process is as follows.

FIG. 9A is a photograph of an actual bonding apparatus and FIG. 9B is a photograph of a solder / EM / solder multi-layer structure pellet ignited and a bonded copper substrate after the burning, FIG. 9C is an initial ignition of the pellet by the tungsten wire igniter, Figure 9D is a cross-sectional SEM image of the bonded body after interfacial bonding.

Figure 9a is a photograph and outline of the actual composite pellets and bonding apparatus used for the bonding process.

In order to prevent ignition and combustion thermal energy from being lost to the outside, a copper substrate (lower plate) to be bonded is placed on a support plate made of teflon, and a composite pellet having a multilayer structure of Solder / EM / Solder is placed thereon The rear copper substrate (upper plate) was covered, and the silicon substrate was placed thereon. A metal interface bond test was performed while igniting the multilayered pellets with a tungsten wire igniter and simultaneously pressing the copper substrate with a pressure of about 1 MPa.

FIG. 9B is a photograph of a successful bonding of a copper substrate after ignition and combustion using a multilayered structure pellet having a solder / EM / solder.

As can be seen from the side view, it was observed that the multi-layered composite pellet with Solder / EM / Solder was fused between the copper substrate after ignition and combustion of the pellet for bonding, and the copper substrate was well fixed and bonded.

That is, it can be confirmed that the solder layer is melted by the reaction heat of the high-energy material, is solidified after cooling process, and is then adhered to the interface of the copper substrate to successfully bond the copper substrate / pellet / copper substrate .

FIG. 9c is a view showing an image obtained by measuring the interfacial bonding process between a copper substrate and a solder / EM / solder multi-layered composite pellet through a high speed camera (FASTCAM SA3 120K) and propagating the flame during ignition and combustion.

The pellet produced in the embodiment of the present invention can be roughly divided into two parts. The ignition pellet corresponding to the first half is composed of EM not including solder, so that the initial ignition can be performed by the tungsten wire igniter. The high temperature flame generated by the initial ignition was continuously transferred to the adjacent high energy material, resulting in macroscopic combustion.

After about 160 ms after initial ignition and combustion at the ignition pellet area, it was observed that the solder / EM / solder multi-layer structure pellet for bonding at the rear part of the pellet was ignited and burned.

Solder / EM / Solder Interfacial bonding between copper substrates has proceeded successfully as the solder layer undergoes dissolution and solidification processes based on the heat of combustion generated by the full-scale combustion reaction of the high-energy material part in the multi-layered composite pellet.

9D is an FE-SEM image of a cross-section of a bonded substrate at room temperature after ignition using a solder / EM / solder multilayer structure pellet.

It can be seen that the solder / EM / solder multilayer structure pellets are well preserved between the copper substrates after ignition.

In addition, it was confirmed that the solder layer was melted by the reaction heat of the high energy material and solidified at room temperature, and then strongly bonded to the interface of the copper substrate to successfully bond the copper substrate / interface pellet / copper substrate. The bond between the substrate and the pellet interface was well established, indicating that the interfacial bonding was good.

That is, in the high-magnification image obtained by enlarging the solidified solder layer, it can be confirmed that the grain growth occurs after the neck growth between the solder powders due to the reaction heat of the high-energy material, It can be seen that a diffusion bonding layer is formed.

FIG. 10 is a comparative graph showing the mechanical tensile strength of two copper substrates bonded together using pure solder pellets and solder / high energy material / solder (EM / solder) multi-layered composite pellets.

The maximum tensile strength of the bond between the two copper substrates was about 36.48 MPa using the solder / EM / solder multilayer structure pellet.

The main cause of tensile stress fracture on the joint is mainly a composite element of normal stress and shear stress. In the joint joint subjected to tensile - shear load, fracture occurs due to peeling of interfacial end.

In the case of solder / EM / solder multi-layered pellet bonding, it is considered that the final bonding of the solder, EM and copper substrate to the complex bonding element occurred.

For comparison of bond strength, pure SAC305 (Sn-3.0Ag-0.5Cu) solder was prepared as pellet without adding high energy material (EM) and placed between copper substrate and external heat source by heater was applied to dissolve pure solder. The maximum tensile strength of the bonded joint was found to be about 26.28 MPa when the copper substrate was solidified.

As a result, the maximum tensile strength of the solder / EM / solder multi-layer structure pellet manufactured by the present invention was significantly increased by about 40% or more as compared with pure solder-based pellets.

This means that when the multi-layered composite pellets according to the present invention, the method for producing the same, and the process in the method for joining metal interfaces using the same are used for interfacing between metal substrates, excellent mechanical bonding strength can be obtained.

The multi-layered composite pellet according to the present invention, the method for manufacturing the same, and the method for joining metallic interfaces using the multi-layered composite pellet according to the present invention can be manufactured by manufacturing a solder / high energy material / solder-based multilayer structure pellet for metal interface bonding, So that the interface bonding process can be performed only by local heating around the bonding portion without heating the entire surrounding environment.

As described above, it will be understood that the present invention is implemented in a modified form without departing from the essential characteristics of the present invention.

It is therefore to be understood that the specified embodiments are to be considered in an illustrative rather than a restrictive sense and that the scope of the invention is indicated by the appended claims rather than by the foregoing description and that all such differences falling within the scope of equivalents thereof are intended to be embraced therein It should be interpreted.

Claims (17)

A first bonding material layer for metal interface bonding;
A second bonding material layer for metal interface bonding;
And a high energy material composite disposed between the first bonding material layer and the second bonding material layer to form a bonding pellet,
The first and second bonding material layers and the high energy material composite are laminated in the order of the first bonding material layer, the high energy material composite and the second bonding material layer, pressure-molded in a circular shape, the bonding pellet is bonded to the tungsten wire Based resistance heat to induce ignition and combustion reaction so that the first and second bonding material layers are melted and bonded to the metal interface by heat energy generated during ignition and combustion of the high energy material composite,
Further comprising an ignition pellet which does not include the first and second bonding material layers and is composed only of a high energy material composite, and the ignition pellet is formed by initial ignition using a tungsten wire-based resistance heat Wherein the high temperature flame is generated to ignite and burn the bonding pellet. delete The multi-layer composite pellet according to claim 1, wherein the first and second bonding material layers are solder powder. The high energy material composite according to claim 1,
Characterized in that aluminum (Al) is used as the fuel material and iron oxide (Fe ₂ O ₃ ) is used as the oxidizer material. The high energy material composite according to claim 1,
Wherein the micro-scale aluminum (Al) particles and the nanoscale aluminum (Al) particles are mixed and used as a fuel material. The high energy material composite according to claim 1,
And further comprising nickel (Ni) nanoparticles for controlling combustion and explosion characteristics and improving bonding strength. The high energy material composite according to claim 1,
Aluminum nanoparticles (Al NP), aluminum microparticles (Al MP), nickel nanoparticles (Ni NP), iron oxide (Fe ₂ O ₃₎ each of the nanoparticles Al NP: Al MP: Ni NP : Fe 2 O 3 NP = 23: 31: 15: 31 wt%, based on the total weight of the composite pellets. 8. The method of claim 7, wherein, during ignition and combustion of the high energy material composite,
Characterized in that the aluminum nanoparticles (Al NP) first react to generate thermal energy by an exothermic reaction and subsequently continuously dissolve the aluminum microparticles (Al MP) and induce an additional exothermic reaction to control the burning rate and the combustion time. Structural composite pellets. Preparing a high energy material composite powder by mixing a fuel material and an oxidizer material;
Depositing a first bonding material powder for metal interface bonding, a high energy material composite powder, and a second bonding material powder for metal interface bonding in this order;
Forming a bonding pellet for metal interface bonding in which a high energy material composite is positioned between the first and second bonding material layers by pressure molding,
The bonding pellet is ignited and the combustion reaction is induced by using the resistance heat based on the tungsten wire so that the first and second bonding material layers are dissolved by the heat energy generated in the ignition and combustion of the high energy material composite, To be bonded to the interface,
An ignition pellet, which does not include the first and second bonding material layers but is composed of a high energy material composite, is manufactured so that an ignition pellet is heated at a high temperature by an initial ignition using a tungsten wire- Wherein the flame is generated to ignite and burn the bonding pellet. [10] The method of claim 9, wherein the first and second bonding materials are solder powder, aluminum (Al) is used as a fuel material constituting the high energy material composite powder, iron oxide (Fe ₂ O ₃ ). ≪ / RTI > The high energy material composite according to claim 9 or 10,
Characterized in that micro scale aluminum (Al) particles and nanoscale aluminum (Al) particles are mixed and used as a fuel material. The high energy material composite according to claim 9 or 10,
(Ni) nanoparticles for controlling combustion and explosion characteristics and improving the bonding strength of the multi-layered composite pellets. The high energy material composite according to claim 9,
Aluminum nanoparticles (Al NP), aluminum microparticles (Al MP), nickel nanoparticles (Ni NP), iron oxide (Fe ₂ O ₃₎ each of the nanoparticles Al NP: Al MP: Ni NP : Fe 2 O 3 NP = 23: 31: 15: 31 wt% based on the total weight of the composite pellets. Preparing a high energy material composite powder by mixing a fuel material and an oxidizer material;
Depositing a first bonding material powder for metal interface bonding, a high energy material composite powder, and a second bonding material powder for metal interface bonding in this order;
Forming a bonding pellet for metal interface bonding in which a high energy material composite is positioned between the first and second bonding material layers by pressure molding;
Placing a bonding pellet between the metal substrate and the metal substrate and dissolving the first and second bonding material layers by thermal energy generated during ignition and combustion of the high energy material composite to bond the metal bonding interface to the metal interface Lt; / RTI >
In the step of dissolving the first and second bonding material layers and bonding them to the metal interface, an ignition pellet comprising only the high energy material composite without the first and second bonding material layers is manufactured, An ignition pellet generates a high temperature flame by initial ignition using resistive heat based on tungsten wires to ignite and burn the bonding pellet,
The ignition of the high energy material composite places the ignition pellet and the bonding pellet between the metal substrate and the metal substrate and induces the ignition and combustion reaction using the resistance heat based on the tungsten wire, Wherein the two metal substrates are pressurized at the interface between the two metal substrates. delete 15. The method of claim 14, wherein micro scale aluminum (Al) particles and nanoscale aluminum (Al) particles are mixed with the fuel material of the high energy material composite,
The aluminum nanoparticles (Al NP) react first at the time of ignition and combustion of the high energy material composite to generate thermal energy by an exothermic reaction, and then continuously dissolving aluminum microparticles (Al MP) and inducing an additional exothermic reaction, And controlling the burning time. The method for joining metal interfaces using a multi-layered composite pellet. 15. The method of claim 14, wherein in the step of causing the first and second bonding material layers to dissolve and bond to the metal interface,
The first and second bonding material layers are melted by the thermal energy generated during ignition and combustion of the high energy material composite and solidified through the cooling process to be fixed to the interface of the metal substrate and a diffusion bonding layer is formed at the interface of the metal substrate Wherein the metal pellets are bonded to each other via a metal layer.

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