KR20160027453A - Hybrid Composite Solder Alloys and Their Fabrication Methods - Google Patents

Abstract

The present invention relates to a hybrid composite solder alloy and a manufacturing method thereof and, more specifically, provides a hybrid composite solder alloy which includes a solder matrix material, a carbon reinforcing material, and a metal medium material wherein each interface layer is formed between the metal medium material and the solder matrix material, and between the metal medium material and the carbon reinforcing material; and the metal medium material is formed by one or more selected from a group of lithium, aluminum, silicon, vanadium, chrome, manganese, iron, yttrium, zirconium, niobium and neodymium. The present invention provides the hybrid composite solder alloy which reinforces the solder matrix material with the carbon reinforcing material and the metal medium material to enhance joint robustness, electricity conductivity, relative density and a melting point. More specifically, provided is the hybrid composite solder alloy which increases the joint strength with a network microstructure; increases electrical conductivity with the carbon reinforcing material with high current density; reduces the relative density with the carbon reinforcing material and the metal medium material having low specific gravity; and forms an intermetal compound and reduces the melting point by arranging the metal medium in the solder matrix material.

Description

≪ Desc / Clms Page number 1 > Hybrid Composite Solder Alloys <

The present invention relates to a hybrid composite solder alloy and a method of manufacturing the same. More particularly, the present invention relates to a hybrid composite solder alloy which is reinforced with a carbon reinforcing material and a metal-based material to improve solder joint rigidity, electrical conductivity, relative density and melting point.

The solder must have sufficient adhesion and wettability to be able to fully bond the electronic components on the circuit board. Also, it should have a strong durability and an earthquake-proof property that does not break the joint part against external impact. At present, solders having excellent spreadability, wettability, durability and vibration resistance are being developed.

With the development of flip chip technology, the distance between the semiconductor chip and the connection pad has been continuously reduced, and there is a demand for a solder having excellent electrical conductivity and a high signal transmission rate even at a small pitch. Accordingly, the solder must have high current density and be capable of quickly and accurately delivering various electric signals to the pins.

In addition, with the recent increase in demand for small and light electronic devices, there is an increasing demand for small and light solders in the semiconductor package field. Advances in precision manufacturing technology enable the production of small-sized solder balls or thin-form solder wires. However, it is very difficult to reduce the weight because the solder is basically composed of heavy metal. Heavy metals are metals whose specific gravity between copper and lead is greater than 4.5 g / cm ³ in the periodic table.

Accordingly, studies have been actively conducted to reduce the specific gravity by employing carbon reinforcement such as small and light graphene, carbon nanotube, and carbon fiber in a solder matrix.

On the other hand, binary tin-lead solder has the same solidus temperature and liquidus temperature of 183.0 ° C, has a low cracking amount during cooling, and has a low melting point temperature, It has the advantage of less possibility of damage.

As the use of lead is restricted due to environmental pollution, lead-free solder substitutes for flexible solder, and in fact, binary tin-lead-free solder is now widely used. However, the onset melting point of the lead-free solder is about 38.0 degrees Celsius higher than that of the flexible solder having an onset melting point of 183.0 degrees Celsius at 221.0 degrees Celsius, which in turn increases the probability of thermal damage to other electronic components have.

Accordingly, a new low melting point, high reliability lead-free solder having a melting point similar to that of conventional solder and having a narrow melting temperature range is currently under development.

Non-Patent Document 1 describes a method for enhancing the shear strength and hardness of a composite solder alloy by reinforcing the multilayer carbon nanotube to a lead-free solder alloy.

However, the multi-layer carbon nanotubes have a low reactivity with the solder alloy, so that the effect of decreasing the melting point due to the formation of the compound is insignificant.

Non-Patent Document 2 discloses a method of increasing the wettability between the multilayer carbon nanotube and the solder alloy by coating nickel on the surface of the multilayer carbon nanotube and simultaneously increasing the ultimate tensile strength of the composite solder alloy have.

However, nickel is relatively unlikely to form carbides with carbon nanotubes because of its relatively low reactivity. In addition, electroplating, physical vapor deposition, and chemical vapor deposition methods have been proposed as coating methods for carbon nanotubes. However, it is very difficult to increase the reactivity of carbon nanotubes by such a method. it's difficult.

Accordingly, the inventors of the present invention confirmed that it is possible to improve the joint stiffness, electrical conductivity, relative density and melting point by strengthening the solder matrix with a carbon reinforcing material and a metal intermediate material while studying the solder alloy exhibiting excellent characteristics Thus completing the present invention.

Non-Patent Document 1: Sha Xu, Yan Cheong Chan, Kaili Zhang, K.C. Yung, J. Alloys Comp., 595, pp. 92102 (2014). Non-Patent Document 2: Zhongbao Yang, Wei Zhou, Ping Wu, Mater. Sci. Eng. A., 590, pp. 295300 (2014).

SUMMARY OF THE INVENTION [0006]

Hybrid composite solder alloy.

Another object of the present invention is to provide

(Step 1) of mixing the respective powders of the solder base material, the carbon reinforcing material and the metal intermediate material; And

And a step of compressing and heat-treating the mixed powder produced in the step 1 (step 2). The present invention also provides a method for producing a hybrid composite solder alloy.

According to an aspect of the present invention,

A composite composite solder alloy comprising a solder matrix, a carbon stiffener, and a metal-

An interfacial layer between the metal-based material, the solder substrate and the carbon reinforcement,

Wherein the metal mediator is at least one selected from the group consisting of lithium, magnesium, aluminum, silicon, titanium, vanadium, chromium, manganese, iron, yttrium, zirconium, niobium and neodymium.

Further, according to the present invention,

(Step 1) of mixing the respective powders of the solder base material, the carbon reinforcing material and the metal intermediate material; And

And a step of compressing and heat-treating the mixed powder produced in the step 1 (step 2).

The present invention provides a hybrid composite solder alloy having solder matrix materials reinforced with a carbon reinforcing material and a metal compound to improve bonding rigidity, electrical conductivity, relative density and melting point. More specifically, the network microstructure increases bond stiffness, increases electrical conductivity with high current density carbon stiffeners, reduces relative density with low specific gravity carbon stiffeners and metal intermediates, To form an intermetallic compound and to reduce the melting point of the composite composite solder alloy.

The hybrid composite solder alloy manufacturing method according to the present invention can form an interfacial layer using a metal-based material through a simple process of mixing, compressing, and heat-treating a solder base material, a carbon reinforcement material, and a metal- A hybrid composite solder alloy can be manufactured.

FIG. 1 is a schematic view showing a process of transferring a hybrid composite solder alloy composition according to the present invention to a hybrid composite solder alloy; FIG.
2 is a photograph of the multilayer carbon nanotube and the hybrid composite solder alloy produced in Example 3 by scanning electron microscope;
FIG. 3 is a graph showing electrical resistivities of the hybrid composite solder alloy prepared in Examples 1 to 9 and Comparative Example 1 according to the content of carbon reinforcing material;
4 is a graph showing the absolute density and the relative density of the hybrid composite solder alloy prepared in Examples 1 to 9 and Comparative Example 1 according to the content of the carbon reinforcing material;
5 is a graph showing the differential scanning calorie of the hybrid composite solder alloy prepared in Examples 2, 4, 6 and 8 and Comparative Example 1;
6 is a graph showing the results of X-ray diffraction analysis of the hybrid composite solder alloy prepared in Examples 2, 4, 6 and 8 and Comparative Example 1;
7 is a photograph of the hybrid composite solder alloy produced in Production Example 3 by scanning electron microscope;
8 is a graph showing electrical resistivities of the hybrid composite solder alloys prepared in Production Examples 1 to 6 and Comparative Example 2 according to the content of carbon reinforcing material;
9 is a graph showing the absolute density and the relative density of the hybrid composite solder alloy produced in Production Examples 1 to 6 and Comparative Example 2 according to the content of the carbon reinforcing material;
10 is a graph showing the differential scanning calorie of the hybrid composite solder alloy prepared in Production Examples 2, 4 and 6 and Comparative Example 2;
11 is a graph showing the results of X-ray diffraction analysis of the hybrid composite solder alloy produced in Production Examples 2, 4 and 6 and Comparative Example 2. FIG.

According to the present invention,

A composite composite solder alloy comprising a solder matrix, a carbon stiffener, and a metal-

An interfacial layer between the metal-based material, the solder substrate and the carbon reinforcement,

Wherein the metal mediator is at least one selected from the group consisting of lithium, magnesium, aluminum, silicon, titanium, vanadium, chromium, manganese, iron, yttrium, zirconium, niobium and neodymium.

Hereinafter, the hybrid composite solder alloy according to the present invention will be described in detail.

The hybrid composite solder alloy according to the present invention is a hybrid composite solder alloy including a solder base material, a carbon reinforcement material and a metal-based material, and has an interface layer between the metal-based material, the solder base material and the carbon reinforcement material.

The present invention provides a hybrid composite solder alloy having solder matrix materials reinforced with a carbon reinforcing material and a metal compound to improve bonding rigidity, electrical conductivity, relative density and melting point.

The present invention provides a hybrid composite solder alloy in which a solder matrix is reinforced with a carbon reinforcing material and a metal matrix to improve bonding rigidity.

Solder bases are relatively high in oxidation resistance and bond stiffness, but they are low in elasticity and impact absorbability, which may lead to peeling at the joints during external impact. The carbon reinforcing material has high elasticity and impact absorbability, but has a low reactivity with the solder base material. This problem can be solved by reacting a metal-based material with a carbon reinforcing material and then using the material in a solder base material. When a compound is formed at the interface between a solder matrix and a carbon stiffener using a metal matrix, the solder matrix having a relatively high oxidation resistance is coated with a carbon matrix and a metal matrix to prevent oxidation. When the bond stiffness Can be increased.

The present invention provides a hybrid composite solder alloy in which the solder matrix is reinforced with a carbon reinforcing material and a metal matrix to improve electrical conductivity.

Carbon reinforcing materials have excellent electrical conductivity. For example, the graphene ribbon (carbon reinforcing material) has a current density of 1.0 × 10 ⁸ A / cm ² , and the single-walled carbon nanotube (carbon reinforcing material) has a current density of 4.0 × 10 ⁹ A / m ² . However, as the nanoscale-to-microcrystalline size increases, the electrical conductivity is degraded, oxidized at high temperatures, and agglomerates due to the hydrophobic interface properties. As a metal mediator, it is possible to prevent the electrical conductivity from being damaged in the process of increasing the rate when the solder base material and the carbon reinforcement material are connected and supplemented. Oxidation can be prevented by using a carbon reinforcing material oxidized at a high temperature coated with a solder base material having a relatively high oxidation resistance. When the solder base material is mixed with the carbon reinforcing material and sintered, the solder base material can be melted and aggregation of the carbon reinforcement material can be released, thereby increasing the electrical conductivity of the hybrid composite solder alloy.

The present invention provides a hybrid composite solder alloy in which the solder matrix is reinforced with a carbon reinforcing material and a metal matrix to improve the relative density.

Because of the low specific gravity of the carbon reinforcing material and the metal matrix, it is possible to reduce the relative density of the hybrid composite solder alloy when used in a solder matrix. The multilayer carbon nanotube (carbon reinforcing material) has a specific gravity of 2.27 g / cm ³ , and the magnesium (metal-mediated material) has a lower specific gravity of 1.74 g / cm ³ . The use of carbon stiffener and metal matrix in the solder matrix can reduce the relative density of the hybrid composite solder alloy.

The present invention provides a hybrid composite solder alloy in which a solder matrix is reinforced with a carbon reinforcing material and a metal matrix to improve the melting point.

The solder base material is excellent in heat resistance and stable at high temperatures, but has a high melting point. For example, lead-free solder alloys based on tin (solder base materials) have an onset melting point as high as 210.0 to 230.0 ° C, and studies for lowering the melting point by adding new elements are currently being actively pursued. When the magnesium (metal-mediator) is dissolved in the lead-free solder alloy (the solder matrix), a magnesium compound is formed and migrated to a eutectic composition, whereby the melting point can be reduced. Therefore, the melting point of the hybrid composite solder alloy can be reduced by employing a metal-mediated material in the solder matrix.

Wherein the solder base material is selected from the group consisting of tin, copper, vanadium, gold, silver, zinc, tungsten, platinum, lead, bismuth, indium, nickel, cobalt, antimony, rare earths, oxides, nitrides, sulfides, At least one selected may be used, but the solder base material is not limited thereto.

As one example of the solder base material, the binary tin-silver solder alloy has high oxidation resistance and heat resistance, is stable at high temperature, and has a relatively high bonding rigidity, so that it is widely used as a bonding material for attaching an electronic component to a circuit board. However, it has low elasticity and shock absorbing property, is weak against external impact, has low electric conductivity as compared with gold, silver, copper, etc., has a high specific gravity and has an onset melting point of 221.0 캜 and an onset melting point of 183.0 캜 It is 38.0 ° C higher than that of 2-element tin-lead flexible solder alloy. In the present invention, the solder matrix is supplemented with a carbon reinforcing material and a metal matrix to solve the problem.

At this time, the hybrid composite solder alloy may include a solder base of 80 to 97 mass%. If the hybrid composite solder alloy contains less than 80 mass% of solder base material (for example, binary tin-silver-free solder alloy), oxidation resistance and heat resistance are low, and more than 97 mass% When the ash is contained, the elasticity and the impact absorbability are small, and thus there is a problem in that it is vulnerable to an external impact.

The carbon reinforcing material may be at least one selected from the group consisting of diamond, fullerene, carbon nanotube, graphene, carbon fiber, carbon black, activated carbon, vitreous carbon, artificial carbon and graphene ribbon.

As an example of the carbon reinforcing material, the multi-layer carbon nanotube has high elasticity and impact absorbability, high electrical conductivity and high specific gravity of 2.27 g / cm < ³ >. However, in the process of increasing the nanoscale to micro size, the electrical conductivity is damaged, oxidized at high temperature, agglomerated severely due to hydrophobic interface properties, chemically stable and reactivity with lead-free solder alloy is low. It is also rapidly oxidized at 530.0 ° C and thermally decomposed at 650.0 ° C.

At this time, the hybrid composite solder alloy may include carbon reinforcement in an amount of 0.01 to 3 mass%. If the hybrid composite solder alloy contains less than 0.01% by mass of carbon reinforcing material (for example, multi-layer carbon nanotubes), there is a problem that the increase in electric conductivity is insignificant. When the carbon reinforcing material is contained in excess of 3% by mass, .

In the hybrid composite solder alloy of the present invention, the metal-based material is at least one selected from the group consisting of lithium, magnesium, aluminum, silicon, titanium, vanadium, chromium, manganese, iron, yttrium, zirconium, niobium, and neodymium do.

Magnesium and aluminum have a specific gravity of 1.74 g / cm ³ and 2.70 g / cm ³ , respectively, and have high reactivity, so that the interface between the multilayer carbon nanotube (carbon reinforcement) and the lead-free solder alloy (solder matrix) ≪ / RTI > In particular, when magnesium is melted in a Pb-free solder alloy, a magnesium compound is formed, which moves to the process composition and the melting point is reduced. Magnesium forms multi-layer carbon nanotubes and magnesium carbide of Mg ₂ C ₃ , forming a lead-free solder alloy and a magnesium compound of Mg ₂ Sn. Magnesium is used as an intermediate material for interconnecting multi-layer carbon nanotubes and lead-free solder alloys. As the magnesium content increases, the magnesium compound increases and the melting point decreases. However, magnesium is easily oxidized.

At this time, the hybrid composite solder alloy may include 0.01 to 10 mass% of a metal-based material. If the mixed composite solder alloy contains less than 0.01% by mass of a metal-containing material (for example, magnesium), the reactivity is insignificant. If the mixed-type solder alloy contains more than 10% by mass of the metal- .

The present invention has the following characteristics of the hybrid composite solder alloy.

Hereinafter, characteristics of a lead-free solder alloy (tin and silver) as an example of a solder base material, a multilayer carbon nanotube as an example of a carbon reinforcement material, and a composite hybrid solder alloy containing magnesium as an example of a metal intermediate material are described.

Hybrid composite solder alloys are used to reliably attach highly irregular electronic components to circuit boards.

Lead-free solder alloys are relatively high in oxidation resistance and bond stiffness, but have low elasticity and shock absorption. The multi-layered carbon nanotube has a complicated mesh microstructure, and has high elasticity and impact absorbability. Magnesium bonds and bonds between the two constituents to prevent peeling of the joints. The composite microstructure of multilayer carbon nanotubes, the relatively high bonding stiffness of the lead-free solder alloy, and the bonding and complementing of the magnesium are combined to further improve the bonding stiffness of the hybrid composite solder alloy.

The multilayer carbon nanotubes have a current density of about copper, so that the electrical conductivity of the hybrid composite solder alloy improves when the solder alloy is reinforced with the lead-free solder alloy. However, if the multilayer carbon nanotubes are excessively strengthened, pores and cracks are generated at the interface between the lead-free solder alloy, and the electrical conductivity of the hybrid composite solder alloy gradually decreases.

Tin and silver have a specific gravity of about 7.37 g / cm ³ and 10.49 g / cm ³ , respectively, but the specific gravity of the multi-layer carbon nanotube, magnesium and aluminum is low, and the specific gravity of the hybrid composite solder alloy is reduced. In particular, multilayer carbon nanotubes are chemically very stable, and if they are strengthened too much, pores and cracks will occur at the interface between the Pb-free solder alloy and the relative density of the hybrid composite solder alloy will decrease sharply.

The hybrid composite solder alloy has an onset melting point of 208.0-199.0 ° C and is capable of controlling the melting point according to the magnesium content. However, magnesium is easily oxidized, and as the magnesium content increases, the electrical conductivity decreases sharply.

According to the present invention,

(Step 1) of mixing the respective powders of the solder base material, the carbon reinforcing material and the metal intermediate material; And

And a step of compressing and heat-treating the mixed powder produced in the step 1 (step 2).

In the method for producing a hybrid composite solder alloy according to the present invention, step 1 is a step of mixing powders of a solder base material, a carbon reinforcing material, and a metal-based material, respectively.

By performing the mixing step in the step 1, the energy state between the powders can be increased, and the solder matrix, the metal medium, the carbon reinforcement and the metal medium are brought into contact with each other so that the interfacial compound can be formed in the subsequent heat treatment process.

The mixing of step 1 may be performed by a ball milling process, and may be performed by mixing each of the powders and then ball milling them.

In addition, in the mixing of the step 1, the carbon reinforcing material and the metal-mediated powder may be mixed first, then the solder base material may be added and mixed again.

At this time, the ball milling process may be performed for 1 minute to 100 hours.

If the composite composite solder alloy is ball milled for less than 1 minute, reactivity with carbon reinforcing material (for example, multi-layer carbon nanotubes) is low. If ball milling is performed for more than 100 hours, carbon reinforcing material is damaged .

In the method for producing a hybrid composite solder alloy according to the present invention, step 2 is a step of compressing and heat-treating the mixed powder prepared in step 1 above.

As the necking is formed between the powders through the compression process of the step 2, diffusion of atoms occurs more easily, and as a result, a compound between each of the solder base material and the carbon reinforcing material and the metal intermediate material can be formed through the heat treatment have.

In this case, the heat treatment in step 2 may be performed at a temperature ranging from 150.0 to 650.0 ° C, and may be performed in a vacuum atmosphere.

If the heat treatment in step 2 is carried out at a temperature lower than 150.0 ° C., there is a problem that magnesium hydride is not dehydrogenated when magnesium is used as a metal mediator, and the heat treatment in step 2 is performed at a temperature higher than 650.0 ° C. There is a problem that unnecessary energy and cost are consumed.

An example of a method for producing a hybrid composite solder alloy according to the present invention is shown below.

After mixing magnesium hydride powder and aluminum powder (metal mediator) with the multilayer carbon nanotube powder (carbon reinforcing material) in the composition, ball milling is performed for 1 hour to increase the energy state. After mixing the tin powder and the silver powder (solder matrix), ball milling is performed for one hour. The milled powder is put into a press mold and a pressure of 20 MPa is applied in a uniaxial direction to form a disk-shaped sample of 1.5 cm in diameter × 2 cm in height. For the dehydrogenation, hybrid heat treatment is performed at a holding temperature of 450.0 ℃ for 3 hours to produce hybrid composite solder alloy.

At this time, an example of the dehydrogenation reaction and the carbonization reaction of the hybrid composite solder alloy by the heat treatment is shown by the following reaction formula.

<Reaction Scheme 1>

_{Sn + Ag + MgH 2 + Al} + MWCNT (carbon) →

Sn + Ag ₃ Sn + Mg ₂ Sn + Mg ₂ C ₃ + Al + MWCNT (carbon) + H ₂ (↑, gas)

As can be seen from the above reaction formula, magnesium hydride has lower reactivity with oxygen in air than magnesium and is used as a magnesium precursor powder material. Magnesium hydride is easily dehydrogenated in a high-temperature vacuum atmosphere at 350.0 ° C or higher to be converted to magnesium, and hydrogen is converted into gas and discharged. The dehydrogenated magnesium forms multi-layer carbon nanotubes and magnesium carbide of Mg ₂ C ₃ , forms a magnesium compound of Mg ₂ Sn and a lead-free solder alloy, and is used as an intermediate between the multi-layer carbon nanotube and the lead-free solder alloy .

The hybrid composite solder alloy may have an electrical resistivity of 0.1 to 400 mu OMEGA cm or a relative density of 0.1 to 7.5 g / cm &lt; ³ &gt; or an onset melting point of 190 to 230 DEG C, more preferably 199.0 to 208.0 DEG C have.

Hereinafter, the present invention will be described in detail with reference to Examples. However, the following examples are intended to illustrate the present invention, but the present invention is not limited to the following examples.

&Lt; Example 1 >

Step 1: Mixing 0.10 mass% of multilayer carbon nanotube (carbon reinforcing material) powder, 0.66 mass% aluminum (metal mediator) powder and 2.89 mass% magnesium (metal mediator) powder, ball milling was performed for 1 hour 93.47% by mass of tin (solder base material) powder and 2.89% by mass of silver (solder base material) powder were mixed, followed by further ball milling for 1 hour.

Step 2: The milled powder was put into a press mold, and a pressure of 20 MPa was applied in a uniaxial direction to form a disc-shaped sample having a diameter of 1.5 cm and a height of 2 cm. A vacuum heat treatment was performed at a holding temperature of 450.0 캜 for 3 hours To produce a hybrid composite solder alloy.

&Lt; Examples 2 to 15 &

A mixed composite solder alloy was prepared in the same manner as in Example 1, except that the mass% of the multilayer carbon nanotubes, aluminum and magnesium, tin and silver in the step 1 of Example 1 was changed as shown in the following table.

Sn
(mass%) Ag
(mass%) Al
(mass%) Mg
(mass%) MWCNT
(mass%) Comparative Example 1 93.56 2.89 0.66 2.89 0.00 Example 1 93.47 2.89 0.66 2.89 0.10 Example 2 93.38 2.88 0.66 2.88 0.19 Example 3 93.19 2.88 0.66 2.88 0.40 Example 4 93.00 2.87 0.66 2.87 0.60 Example 5 92.81 2.87 0.65 2.87 0.80 Example 6 92.62 2.86 0.65 2.86 1.00 Example 7 92.44 2.86 0.65 2.86 1.20 Example 8 92.25 2.85 0.65 2.85 1.40 Example 9 92.06 2.84 0.65 2.84 1.60

&Lt; Comparative Example 1 &

(Metal-mediator) powder, 2.89 mass% magnesium (metal-mediator) powder, 93.51 mass% tin (solder matrix) powder, 2.89 mass% silver Solder base material) powders were mixed in the same manner as in Example 1, thereby preparing a hybrid composite solder alloy.

&Lt; Comparative Example 2 &

In step 1 of Example 1, the multi-layer carbon nanotubes were not included, and 0.68 mass% aluminum (metal-mediator) powder, 0.00 mass% magnesium (metal-mediator) powder, 96.34 mass% tin ) Powder, and 2.98% by mass of silver (solder base material) powder were mixed, to prepare a solder alloy.

<Experimental Example 1> Production of hybrid composite solder alloy, microstructure and composition observation

In order to observe the manufacturing process and components of the hybrid composite solder alloy prepared in Examples 1 to 9 and Comparative Example 1, the composition of the hybrid composite solder alloy is shown in Table 1, and the composite composite solder alloy constituent such as multi-layer carbon nanotubes FIG. 1 shows a process of transferring the composite solder alloy to a hybrid composite solder alloy. FIG. 2 shows a result of observation by a scanning electron microscope to observe the microstructure of the hybrid composite solder alloy. The result is shown in FIG. The composition of the composite solder alloy is shown in FIG.

As shown in Fig. 1, magnesium (metal-mediator) reacts with multi-layer carbon nanotubes (carbon reinforcement) to form magnesium carbide, reacts with a lead-free solder alloy (solder matrix) to form a magnesium compound, A hybrid composite solder alloy may be produced in which the metal matrix and the multi-walled carbon nanotube are solid-dissolved in the ash. Accordingly, various characteristics such as bonding rigidity, electrical conductivity, relative density, and melting point improvement of the hybrid composite solder alloy can be expressed.

As shown in Fig. 2, the hybrid composite solder alloy produced in Example 3 exhibits a network microstructure as the multi-walled carbon nanotube has a complicated microstructure.

2-element tin-silver lead-free solder alloy (solder base material) is relatively high in oxidation resistance and bonding stiffness. The multilayer carbon nanotubes (carbon reinforcement) have a complicated microstructure. Magnesium (metal-mediated) is highly reactive. Therefore, the lead-free solder alloy (solder matrix), which has a relatively high oxidation resistance and bonding rigidity, is reinforced with multi-layer carbon nanotubes (carbon reinforcement) having a complicated microstructure and magnesium having high reactivity It can be seen that a hybrid composite solder alloy can be produced.

As shown in Fig. 6, the solder alloy produced in Comparative Example 1 containing no multi-layer carbon nanotubes (carbon reinforcement) showed no carbide peaks, but in Examples 2 and 4 containing multi-walled carbon nanotubes (carbon reinforcement) , 6, and 8 show carbide peaks.

As a result, magnesium (metal-mediated material) reacts with multi-layer carbon nanotubes (carbon reinforcing material) to form magnesium carbide, and reacts with lead-free solder alloy (solder matrix) to form a magnesium compound.

<Experimental Example 2> Electrical characteristics of hybrid composite solder alloy

The electrical resistivity was measured with a sheet resistance meter (FPP-RS8, Dasol Engineering, Korea) in order to examine the electrical characteristics of the hybrid composite solder alloy prepared in Examples 1 to 9 and Comparative Example 1, Respectively.

As shown in Fig. 3, the content of the multilayer carbon nanotube (carbon reinforcement) is 0.00 to 1.60 mass%, and the electrical resistivity is 63.28 to 268.27 占 · m.

As a result, the electrical resistivity of the hybrid composite solder alloy decreases until the content of the multilayer carbon nanotubes (carbon reinforcement) is 0.60 mass%. However, when the content of the multilayer carbon nanotubes (carbon reinforcement) exceeds 0.60 mass%, the electrical resistivity of the hybrid composite solder alloy gradually increases. Therefore, when the content of the multilayer carbon nanotubes (carbon reinforcement) is about 0.60 mass%, the hybrid composite solder alloy has the smallest electrical resistivity and can exhibit excellent electrical characteristics when applied to an electronic device.

<Experimental Example 3> Density of hybrid composite solder alloy

In order to investigate the density of the hybrid composite solder alloy prepared in Examples 1 to 9 and Comparative Example 1, absolute density and relative density were measured with an Archimedes type density meter (AG204, Analytical Balance, METTLER TOLEDO, Switzerland) Is shown in FIG.

4, a multi-wall carbon nanotubes (carbon reinforcing material) content of 0.00 to 1.60% by mass, and thus the absolute Density is 7.262 to 7.182 g / cm ^3, a relative density of 7.258 to 7.042 g / cm ^3.

As a result, it can be seen that the absolute density of the hybrid composite solder alloy decreases as the content of the multilayer carbon nanotube (carbon stiffener) increases due to the specific gravity of the multilayer carbon nanotube (carbon reinforcement) of 2.27 g / cm ³ . On the other hand, the wettability of multi-layer carbon nanotubes (carbon reinforcing material) is lower than that of lead-free solder alloy (solder matrix), and as the content of multi-layer carbon nanotubes (carbon stiffener) increases, the pores and cracks of hybrid composite solder alloy increase. Therefore, as the content of the multilayer carbon nanotubes (carbon stiffener) increases, the relative density of the hybrid composite solder alloy sharply decreases, which can be applied to a lighter electronic device.

Experimental Example 4 Melting Point of Hybrid Composite Solder Alloy

FIG. 5 shows differential scanning calorimetry after measurement with a differential scanning calorimeter (Q100, TA Instrument, USA) to investigate the melting points of the hybrid composite solder alloys prepared in Examples 1 to 9 and Comparative Example 1. FIG.

As shown in Fig. 5, the content of the multilayer carbon nanotubes (carbon reinforcement) is 0.00 to 1.60 mass%, and accordingly, the onset melting point is 208.0 to 199.0 占 폚.

As a result, the melting point of the hybrid composite solder alloy is relatively small as the content of the multi-layer carbon nanotubes (carbon stiffener) increases. However, the content of the multi-layer carbon nanotubes The melting point of the solder alloy is lowered, so that the process can be carried out at a lower temperature.

<Experimental Example 5> Characteristics of solder alloy according to magnesium (metal-mediated) content

In order to observe the microstructure and components of the solder alloy prepared in the following Production Examples 1 to 6 and Comparative Example 2, the composition of the solder alloy is shown in Table 1, and the microstructure photograph of the solder alloy manufactured in Production Example 3 is shown in Table 1 Observed with a microscope, and shown in FIG. 7. The composition of the hybrid composite solder alloy was observed with an X-ray diffractometer and then shown in FIG.

In order to examine the electrical properties of the solder alloy, the electrical resistivity was measured with a sheet resistance meter (FPP-RS8, Dasol Engineering, Korea) and is shown in FIG. 8. The absolute density and the relative density The measurement of the melting point of the solder alloy was carried out using a differential scanning calorimeter (Q100, TA Instrument, USA) and measured by differential scanning calorimetry The amount of heat is shown in Fig.

&Lt; Preparation Examples 1 to 6 &

The procedure of Example 1 was repeated except that the multilayer carbon nanotubes were not included in the step 1 of Example 1 and the mass% of aluminum, magnesium, tin, and silver was changed as shown in the following table, .

Sn
(mass%) Ag
(mass%) Al
(mass%) Mg
(mass%) Comparative Example 2 96.34 2.98 0.68 0.00 Production Example 1 95.41 2.95 0.67 0.97 Production Example 2 94.48 2.92 0.67 1.93 Production Example 3 93.56 2.89 0.66 2.89 Production Example 4 92.62 2.86 0.65 3.86 Production Example 5 91.69 2.84 0.65 4.83 Production Example 6 90.75 2.81 0.64 5.80

As shown in Fig. 7, it can be seen that a large number of pores are irregularly present on the surface of the solder alloy manufactured in Production Example 3. [

As shown in Fig. 11, the solder alloy prepared in Comparative Example 2 containing no magnesium (metal-mediating material) did not show a magnesium compound peak, but it was found that, in Examples 2, 4 and 6 containing magnesium (metal- It can be seen that the magnesium compound peak appears in the solder alloy. As a result, magnesium (metal-mediated) reacts with the lead-free solder alloy (solder matrix) to form a magnesium compound, so that the metal matrix and the solder matrix can be better coupled.

As shown in Fig. 8, the content of magnesium (metal-mediated material) is 0.00 to 5.80 mass%, and the electrical resistivity thereof is 49.06 to 108.04 [micro] [Omega] -cm. Thus, it can be seen that as the magnesium (metal-mediated) content increases, the hybrid composite solder alloy easily oxidizes and the electrical resistivity gradually increases.

9, the magnesium (metal intermediate material) content of 0.00 to 5.80 mass%, and this according to the absolute density is 7.426 to 7.096 g / cm ^3, a relative density of 7.422 to 7.061 g / cm ^3. Accordingly, magnesium (metal intermediate material) can be seen that the absolute density is reduced in the mixed combined solder alloy has a specific gravity of about 1.74 g / cm ³ Mg (metal intermediate material) As the content increases, magnesium (metal intermediate material ), The relative density of hybrid composite solder alloy decreases gradually.

As shown in Fig. 10, the magnesium (metal-mediator) content is 0.00 to 5.80 mass%, and thus the onset melting point is 215.0 to 198.0 占 폚. As a result, magnesium (metal-based material) forms an intermetallic compound with lead-free solder alloy (solder matrix) and moves to the process composition, so that the melting point of the solder alloy decreases.

Claims (14)

A composite composite solder alloy comprising a solder matrix, a carbon stiffener, and a metal-
An interfacial layer between the metal-based material, the solder substrate and the carbon reinforcement,
Wherein the metal-based material is at least one selected from the group consisting of lithium, magnesium, aluminum, silicon, titanium, vanadium, chromium, manganese, iron, yttrium, zirconium, niobium and neodymium.
The method according to claim 1,
Wherein the solder base material is selected from the group consisting of tin, copper, vanadium, gold, silver, zinc, tungsten, platinum, lead, bismuth, indium, nickel, cobalt, antimony, rare earths, oxides, nitrides, sulfides, Wherein at least one selected from the group consisting of copper and tin is selected from the group consisting of copper,
The method according to claim 1,
Wherein the carbon reinforcing material is at least one selected from the group consisting of diamond, fullerene, carbon nanotube, graphene, carbon fiber, carbon black, activated carbon, vitreous carbon, artificial carbon and graphene ribbon.
The method according to claim 1,
Wherein the hybrid composite solder alloy comprises from 80 to 97 mass percent of a solder matrix.
The method according to claim 1,
Wherein the hybrid composite solder alloy comprises from 0.01 to 3 mass% of carbon reinforcement.
The method according to claim 1,
Wherein the hybrid composite solder alloy comprises 0.01 to 10 mass% of a metal-based material.
(Step 1) of mixing the respective powders of the solder base material, the carbon reinforcing material and the metal intermediate material; And
And compressing and heat-treating the mixed powder produced in step 1 (step 2).
8. The method of claim 7,
Wherein the mixing of step 1 is performed by a ball milling process.
9. The method of claim 8,
Wherein the ball milling process is performed for 1 minute to 100 hours.
8. The method of claim 7,
Wherein the mixing of step 1 is performed by first mixing a carbon reinforcing material and a metal-mediated powder, and then adding a solder base material and mixing the mixture.
8. The method of claim 7,
Wherein the heat treatment in step 2 is performed in a temperature range of 150.0 to 650.0 ° C.
The method according to claim 1,
Wherein the hybrid composite solder alloy has an electrical resistivity of 0.1 to 400 占 ㎝ m.
The method according to claim 1,
Wherein said hybrid composite solder alloy has a relative density between 0.1 and 7.5 g / cm &lt; ³ &gt;.
The method according to claim 1,
Wherein the hybrid composite solder alloy has an onset melting point of 190 to 230 占 폚.

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