KR102231919B1 - MoCu HEAT DISSIPATION MATERIAL WITH CARBON PARTICLES AND PREPARING METHOD THEREOF - Google Patents

Abstract

The present invention is a MoCu heat dissipating material and a method for manufacturing the same, comprising: a core made of molybdenum powder by infiltrating copper (Cu) in a Mo mixed powder molded body formed by mixing molybdenum (Mo) powder, a binder, and carbon powder; And it relates to a MoCu heat dissipating material having carbon powder and a method of manufacturing the same, characterized in that the copper is infiltrated into the pores of the binder to be carbonized and removed, and includes the carbon powder, and comprises a copper matrix surrounding the core.
The MoCu heat dissipating material and its manufacturing method according to the present invention can provide a MoCu heat dissipating material having carbon powder having improved heat dissipation properties and reducing a thermal expansion coefficient by adding carbon to the MoCu heat dissipating material, and a method of manufacturing the same.

Description

MoCu heat dissipation material having carbon powder and its manufacturing method {MoCu HEAT DISSIPATION MATERIAL WITH CARBON PARTICLES AND PREPARING METHOD THEREOF}

The technical idea of the present invention relates to a MoCu heat dissipation material having carbon powder and a method of manufacturing the same, and more particularly, MoCu heat dissipation having a carbon powder having a carbon powder having a reduced thermal expansion coefficient and improved heat dissipation properties by adding carbon to the MoCu heat dissipating material. It relates to a material and a method of manufacturing the same.

In a semiconductor package, the heat dissipation substrate is bonded to a semiconductor device or a ceramic substrate to induce smooth heat emission from the semiconductor device. The amount of heat generated is increasing as the semiconductor device becomes high-power and high-capacity. In order to maintain the performance of the semiconductor device, various materials and structures are used for the heat dissipation substrate for a semiconductor package.

For example, as a W-Cu composite material, a porous sintered body is made by sintering tungsten (W) powder at high temperature, and a composite material made by injecting copper (Cu) into the sintered body, but there is a limit to increasing the content of Cu. It is used for high-power and large-capacity semiconductor packages, but there are restrictions.

In addition, when the heat dissipating material is bonded to a dissimilar material, thermal stress may occur due to a difference in the coefficient of thermal expansion with the dissimilar material. Such thermal stress may cause a crack or damage a joint, deteriorating the reliability of the product and shortening the life of the product.

In particular, since the lower the coefficient of thermal expansion at high temperatures is advantageous, a heat dissipating material capable of solving the above problems and a method of manufacturing the same are required.

1. Korean Patent Registration No. 10-1890396 2. Korean Patent Registration No. 10-0674216

The technical problem to be achieved by the technical idea of the present invention is to provide a MoCu heat dissipating material having a carbon powder having a reduced coefficient of thermal expansion and improved heat dissipation properties by adding carbon to the MoCu heat dissipating material.

The technical problem to be achieved by the technical idea of the present invention is to provide a method of manufacturing a MoCu heat dissipating material having a carbon powder capable of adjusting heat dissipation characteristics by adjusting the amount of carbon powder to be mixed in a binder.

However, these problems are exemplary, and the technical idea of the present invention is not limited thereto.

MoCu heat dissipation material having carbon powder according to the technical idea of the present invention to achieve the above technical problem is a Mo mixed powder molded body formed by mixing molybdenum (Mo) powder, a binder and carbon (carbon) powder copper (Cu) A core made of the molybdenum powder by infiltration; And a copper matrix including the carbon powder and surrounding the core by infiltrating the copper into the voids of the binder that is carbonized and removed.

In some embodiments of the present invention, the MoCu heat dissipating material may contain 30 to 50 wt% of copper.

In some embodiments of the present invention, the MoCu heat dissipating material may include 8 to 12 parts by weight of carbon powder based on 100 parts by weight of molybdenum (Mo) powder.

In some embodiments of the present invention, the MoCu heat dissipation material has a thermal conductivity of 185 to 220 W/mK, a thermal expansion coefficient of 8 to 8.8×10 ^-6 /K at a temperature of room temperature to 400°C, and a temperature of room temperature to 800°C. May be greater than or equal to 7×10 ^-6 /K and less than 8.5×10 ^-6 /K.

The manufacturing method of a MoCu heat dissipating material having a carbon powder according to the technical idea of the present invention for achieving the above technical problem is the step of preparing a Mo mixed powder by mixing molybdenum (Mo) powder, a binder, and a carbon (carbon) powder, the Pressing the Mo mixed powder to prepare a Mo mixed powder molded body, and infiltration of copper (Cu) in the Mo mixed powder molded body to prepare a MoCu heat dissipating material.

In some embodiments of the present invention, in the manufacturing of the MoCu heat dissipating material, the copper is infiltrated into the voids of the binder that is carbonized and removed, and includes the core made of molybdenum and the carbon powder, and surrounds the core. Can form a copper matrix.

In some embodiments of the present invention, in the step of preparing the Mo mixed powder, 2 to 6 parts by weight of a binder and 8 to 12 parts by weight of a carbon powder may be mixed based on 100 parts by weight of molybdenum (Mo) powder. .

In some embodiments of the present invention, in the step of preparing the Mo mixed powder, a powder of molybdenum (Mo) having an average particle diameter of 3 to 5 μm and a carbon powder having an average particle diameter of 2 to 3 μm may be mixed. .

In some embodiments of the present invention, in the step of preparing the Mo mixed powder, the powder may be dried at 110 to 130° C. and then the particle size may be selected into 300 to 350 mesh.

In some embodiments of the present invention, the step of preparing the Mo-mixed powder molded body may pressurize the Mo-mixed powder to 70 to 100 kgf/cm 2.

In some embodiments of the present invention, in the manufacturing of the MoCu heat dissipating material, the copper may be infiltrated at a temperature of 1350 to 1450° C. in a hydrogen reducing atmosphere.

The MoCu heat dissipating material having carbon powder according to the technical idea of the present invention may provide a MoCu heat dissipating material having reduced thermal expansion coefficient and improved heat dissipation characteristics by adding carbon.

In addition, in the method of manufacturing a MoCu heat dissipating material having carbon powder according to the present invention, heat dissipation characteristics can be adjusted by adjusting the amount of carbon powder to be mixed in the binder.

The above-described effects of the present invention have been described by way of example, and the scope of the present invention is not limited by these effects.

1 is a process flow chart showing a method of manufacturing a MoCu heat dissipating material having carbon powder according to an embodiment of the present invention.
2 is a cross-sectional SEM photograph and an EDS component analysis graph of a MoCu heat dissipating material according to an embodiment of the present invention.
3 shows the result of EDS Mapping analysis of MoCu heat dissipation material according to an embodiment of the present invention.
4 shows the thermal conductivity of the MoCu heat dissipating material according to an embodiment of the present invention.
5 shows the coefficient of thermal expansion of the MoCu heat dissipating material according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more completely explain the technical idea of the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, and The scope of the technical idea is not limited to the following examples. Rather, these embodiments are provided to make the present disclosure more faithful and complete, and to completely convey the technical idea of the present invention to those skilled in the art. As used herein, the term “and/or” includes any and all combinations of one or more of the corresponding listed items. Identical symbols mean the same elements all the time. Furthermore, various elements and areas in the drawings are schematically drawn. Therefore, the technical idea of the present invention is not limited by the relative size or spacing drawn in the accompanying drawings.

MoCu heat dissipation material having carbon powder according to the present invention is obtained by infiltration of copper (Cu) in a Mo mixed powder molded body formed by mixing molybdenum (Mo) powder, a binder, and carbon powder to obtain the molybdenum powder. Made up of a core; And a copper matrix including the carbon powder by infiltrating the copper in the voids of the binder to be removed by carbonization and surrounding the core (chin). That is, the matrix may be composed of carbon powder and copper, and may have a structure in which carbon powder and copper exist between molybdenums.

The MoCu heat dissipation material may include 30 to 50 wt% of copper. When the copper content is less than 30 wt%, thermal conductivity characteristics may be deteriorated. In addition, when the copper content exceeds 50 wt%, it is easy to deform from an external impact, and the shape retention is deteriorated, and it is difficult to expect an increase in thermal conductivity due to an increase in the copper content.

The MoCu heat dissipation material has a thermal conductivity of 185 to 220 W/mK at room temperature (RT, 25 to 30°C), a thermal expansion coefficient of 8 to 8.8×10 ^-6 /K at room temperature (RT) to 400°C, and room temperature (RT ) At a temperature of 800° C. and ^{may be greater than or equal to 7×10 -6} /K and less than 8.5×10 ^-6 /K. The copper matrix including the carbon powder may reduce the coefficient of thermal expansion of the MoCu heat dissipating material and improve heat dissipation properties. It is possible to prevent physical deformation occurring during the manufacturing process by reducing the coefficient of thermal expansion while ensuring heat dissipation properties such as thermal conductivity.

1 is a process flow chart showing a method of manufacturing a MoCu heat dissipating material having carbon powder according to an embodiment of the present invention. As shown in Figure 1, the method of manufacturing a MoCu heat dissipating material having a carbon powder according to the present invention comprises the step of preparing a Mo mixed powder (S100), a step of producing a Mo mixed powder molded body (S200), and the MoCu heat dissipating material. It includes a manufacturing step (S300).

The step of preparing the Mo mixed powder (S100) is a step of preparing a Mo mixed powder by mixing molybdenum (Mo) powder, a binder, and carbon powder.

2 to 6 parts by weight of a binder and 8 to 12 parts by weight of a carbon powder may be mixed based on 100 parts by weight of the molybdenum (Mo) powder. When the weight category of the binder satisfies about 2 to 6 parts by weight relative to 100 parts by weight of the molybdenum (Mo) powder, the shape retention ability of the Mo mixed powder molded body according to the present invention may be improved, and when copper is infiltrated, the copper It can be formed in a certain amount in the Mo mixed powder molded body.

In addition, 8 to 12 parts by weight of carbon powder may be mixed, and the MoCu heat dissipating material according to the present invention may adjust heat dissipation characteristics by adjusting the amount of carbon powder mixed in the binder.

In addition, a powder of molybdenum (Mo) having an average particle diameter of 3 to 5 µm and a carbon powder having an average particle diameter of 2 to 3 µm may be mixed. When the average particle diameter of the molybdenum (Mo) powder is more than 5 μm, the formation of a copper matrix surrounding the molybdenum (Mo) powder may be reduced during copper infiltration, and the increase in the thermal conductivity and the decrease in the coefficient of thermal expansion for the purpose of the present invention It is difficult to expect. In addition, carbon powder having an average particle diameter of 2 to 3 µm may be mixed and included in the infiltrated copper matrix.

After mixing the powder, the powder may be dried at 110 to 130° C. and then the particle size may be sorted into 300 to 350 mesh.

The step of preparing the Mo-mixed powder molded body (S200) is a step of producing a Mo-mixed powder molded body by pressing the Mo-mixed powder. The Mo mixed powder may be pressurized to 70 to 100 kgf/cm 2.

The MoCu heat dissipating material according to the present invention can be improved in shape retention by producing a Mo-mixed powder molded body through pressurization, and when copper is infiltrated into the Mo-mixed powder molded body in a certain amount, copper is infiltrated into the material inside and on the surface. It can be formed uniformly.

The step of preparing the MoCu heat dissipating material (S300) is a step of manufacturing a MoCu heat dissipating material by infiltration of copper (Cu) in the Mo-mixed powder molded body. The copper is infiltrated into the voids of the binder removed by carbonization to form a copper matrix including the core made of molybdenum and the carbon powder and surrounding the core.

In the step of manufacturing the MoCu heat dissipating material (S300), copper is infiltrated into the Mo-mixed powder molded body to form a uniform MoCu heat dissipating material, and also cracks or voids in the interior or surface of the MoCu heat dissipating material. The occurrence of defects such as) can be prevented.

In particular, the copper may be infiltrated at a temperature of 1350 to 1450 °C in a hydrogen reducing atmosphere. When the above temperature range is satisfied, the present invention can remove oxides remaining on the surface, and copper can be uniformly formed inside and on the surface of the MoCu heat dissipating material.

In addition, a manufacturing process for removing the binder is not required, and the binder may be carbonized and removed at 400 to 500° C. during the process of raising the temperature for copper infiltration. The copper is infiltrated into the voids of the binder removed by carbonization to form a copper matrix including the carbon powder.

This can reduce the coefficient of thermal expansion of the MoCu heat dissipating material and improve heat dissipation properties. It is possible to prevent physical deformation occurring during the manufacturing process by reducing the coefficient of thermal expansion while ensuring heat dissipation properties such as thermal conductivity.

Hereinafter, details of the process of the present invention will be described through examples and experimental examples.

(Example 1)

-MoCu heat dissipation material manufacturing

A slurry was prepared by mixing 4 g of binder polyvinyl alcohol (PVA, HS-BD25) and 10 g of carbon powder having a particle size of 2 to 3 μm, diluted in an alcohol solvent, and 100 g of molybdenum (Mo) powder having an average particle diameter of 4 μm Was added and mixed.

This was introduced into a rotary evaporator to remove the solvent while mixing and heating. Thereafter, the mixed powder from which the solvent was removed was dried in a dryer maintained at 120°C. The dried powder was sized with 325 mesh, and then a Mo mixed powder molded body was manufactured using a press molding apparatus. At this time, the molding pressure was 85 kgf/cm 2 and was manufactured with a mold size of 50 x 30 x 2.0 mmt.

Next, a copper sheet was placed on the Mo mixed powder molded body, and charged to a heat treatment furnace in a hydrogen atmosphere to prepare a MoCu heat dissipating material in which about 35 wt% of copper was impregnated (Mo-35%Cu). At this time, the infiltration temperature was 1400°C. Then, the infiltrated MoCu heat dissipating material was cooled in a nitrogen atmosphere.

-MoCu heat dissipation material heat dissipation characteristics

2A is a cross-sectional SEM photograph of a MoCu heat dissipating material according to an embodiment of the present invention, and FIG. 2B is a graph showing an EDS component analysis result of an infiltrated copper matrix according to an embodiment of the present invention. As shown in FIG. 2, it can be seen that a core made of molybdenum powder and a carbon powder are included, and a copper matrix surrounding the core is formed.

3 shows the result of EDS Mapping analysis of MoCu heat dissipation material according to an embodiment of the present invention. It can be seen that copper is uniformly infiltrated into the MoCu heat dissipating material, and there are no defects such as voids, and it can be seen that molybdenum, carbon powder, and copper are uniformly distributed.

As a comparative example, the thermal conductivity of the MoCu heat dissipating material (Mo-35%Cu) prepared without including carbon powder and the MoCu heat dissipating material according to the present invention was measured and compared. As a result, under the same conditions, the MoCu heat dissipating material prepared without carbon powder had a thermal conductivity of 200 W/mK, and the MoCu heat dissipating material prepared with carbon powder had a heat conductivity of 206.7 W/mK. With this, it can be seen that carbon is added to the MoCu heat dissipation material to improve heat dissipation properties.

Table 1 is a table confirming the coefficient of thermal expansion of the MoCu heat dissipating material according to an embodiment of the present invention. The coefficient of thermal expansion was measured in a temperature range from room temperature (RT: 25 to 30°C) to 800°C. As shown in Table 1, the MoCu heat dissipation material prepared without carbon powder as a comparative example ^{has a thermal expansion coefficient of 8.9×10 -6} /K at a temperature of RT to 400°C, and the MoCu heat dissipation material according to the present invention is RT~ ^{It was confirmed that the thermal expansion coefficient of 8.37×10 -6} /K at temperatures up to 400°C was added, thereby reducing the coefficient of thermal expansion and improving the heat dissipation characteristics by adding carbon.

In addition, the MoCu heat dissipating material prepared without including carbon powder ^{has a coefficient of thermal expansion of 8.5×10 -6} /K at a temperature of RT to 800°C, and the MoCu heat dissipating material according to the present invention is 7.75× at a temperature of RT to 800°C. It has a coefficient of thermal expansion of 10 ^-6 /K, which can be advantageously applied as the coefficient of thermal expansion is lower at high temperatures when bonding different materials at an actual brazing temperature of 800 to 900°C.

Coefficient of thermal expansion (10 ^-6 /K) Temperature range RT~100℃ RT~200℃ RT~300℃ RT~400℃ RT~500℃ RT~600℃ RT~700℃ RT~800℃ Comparative example - - - 8.9 - - - - Example 10.06 9.07 8.58 8.37 8.27 8.05 7.85 7.75

(Example 2)

While changing the content of carbon powder, a MoCu heat dissipating material according to an embodiment of the present invention was prepared (Mo:Cu=65:35, Mo-35%Cu). In order to keep the copper (Cu) content constant, the content of the binder polyvinyl alcohol (PVA, HS-BD25) was adjusted. Except for changing the content of the carbon powder and the binder, all processes were performed in the same manner as in Example 1. 5 to 15 parts by weight of carbon powder was mixed based on 100 parts by weight of molybdenum (Mo) powder.

Table 2 shows, as an embodiment of the present invention, the thermal conductivity and thermal expansion coefficient of the MoCu heat dissipating material according to the content of carbon powder.

When 8 to 15 parts by weight of carbon powder is mixed, the thermal conductivity becomes 180W/(m*K) or more, and when 10 to 12 parts by weight of carbon powder is mixed, the thermal conductivity exceeds 200W/(m*K), making it without carbon powder. It showed higher thermal conductivity than one MoCu heat dissipation material (Mo-35%Cu).

On the other hand, when the carbon powder is mixed in less than 15 parts by weight, the coefficient of thermal expansion is decreased compared to the MoCu heat dissipating material prepared without including the carbon powder. If 5 to 12 parts by weight of carbon powder are mixed, the coefficient of thermal expansion decreases to 8.03 to 8.77×10 ^-6 /K at RT~400℃, and the coefficient of thermal expansion at RT~800℃ is 7.22~8.37×10 ^-6 / It decreased to K, and showed a lower coefficient of thermal expansion than the MoCu heat dissipating material (Mo-35%Cu) prepared without including carbon powder.

As such, it can be seen that the addition of carbon powder to the MoCu heat dissipation material reduces the coefficient of thermal expansion and improves the heat dissipation characteristics. When 8 to 12 parts by weight of carbon powder are mixed, the thermal conductivity is 185 to 220 W/(m*K), the coefficient of thermal expansion at RT to 400°C is 8 to 8.8×10 ^-6 /K, and thermal expansion at RT to 800°C. MoCu heat dissipation material having a coefficient of 7×10 ^-6 /K or more and ^{less than 8.5×10 -6 /K can be obtained.} In particular, if 10 to 12 parts by weight of carbon powder are mixed, the thermal conductivity is 200 to 220 W/(m*K), the thermal expansion coefficient is 8.3 to 8.8 × 10 ^-6 /K at RT to 400°C, and at RT to 800°C. MoCu heat dissipation material with a thermal expansion coefficient of 7~8×10 ^-6 /K can be obtained, and its thermal conductivity is higher than that of MoCu heat dissipation material (Mo-35%Cu) manufactured without carbon powder, resulting in a lower coefficient of thermal expansion. Showed.

Content of carbon powder (parts by weight): Based on 100 g of Mo powder Remark Thermal conductivity
(W/(m*K)) 0 5 8 10 12 15 Coefficient of thermal expansion
(10 ^-6 /K) 200 179.08 185.03 206.7 212.8 193.6 RT 8.9 8.03 8.41 8.37 8.77 9.50 RT~400℃ 8.5 8.37 8.14 7.75 7.22 8.94 RT~800℃

As described above, the MoCu heat dissipating material having carbon powder according to the present invention can provide a MoCu heat dissipating material in which carbon is added to reduce the coefficient of thermal expansion and improve heat dissipation characteristics. In addition, the method of manufacturing a MoCu heat dissipating material having carbon powder according to the present invention can adjust heat dissipation characteristics by adjusting the amount of carbon powder to be mixed in the binder.

The technical idea of the present invention described above is not limited to the above-described embodiment and the accompanying drawings, and that various substitutions, modifications and changes are possible within the scope not departing from the technical idea of the present invention, the technical idea of the present invention It will be obvious to those of ordinary skill in the art to which this belongs.

Claims (10)

Molybdenum (Mo) powder, a binder and carbon (carbon) powder are mixed and formed by infiltration of copper (Cu) in the Mo mixed powder molded body,
A core made of the molybdenum powder; And
MoCu heat dissipation material having carbon powder, characterized in that the copper is infiltrated into the pores of the binder to be carbonized and removed, and includes the carbon powder, and comprises a copper matrix surrounding the core.
The method of claim 1,
The MoCu heat dissipation material is a MoCu heat dissipation material having carbon powder, characterized in that it contains 30 to 50 wt% of copper.
The method of claim 1,
The MoCu heat dissipation material includes 8 to 12 parts by weight of carbon powder based on 100 parts by weight of molybdenum (Mo) powder.
The method of claim 1,
The MoCu heat dissipation material has a thermal conductivity of 185 to 220 W/mK, a coefficient of thermal expansion of 8 to 8.8×10 ^{-6 /K at a temperature of room temperature to 400°C, and 7×10 -6} /K or more at a temperature of room temperature to 800°C. MoCu heat dissipation material having carbon powder, characterized in that less than ×10 ^{-6 /K.}
Preparing a Mo mixed powder by mixing molybdenum (Mo) powder, a binder, and carbon powder;
Pressing the Mo-mixed powder to prepare a Mo-mixed powder molded body; And
A method for producing a MoCu heat dissipating material having carbon powder, comprising the step of preparing a MoCu heat dissipating material by infiltration of copper (Cu) in the Mo mixed powder molded body.
The method of claim 5,
In the step of preparing the MoCu heat dissipation material, the copper is infiltrated into the voids of the binder to be carbonized and removed, and a copper matrix including the core made of molybdenum and the carbon powder and surrounding the core is formed. Method for producing a MoCu heat dissipating material having carbon powder.
The method of claim 5,
The step of preparing the Mo mixed powder comprises mixing 2 to 6 parts by weight of a binder and 8 to 12 parts by weight of a carbon powder based on 100 parts by weight of molybdenum (Mo) powder. Manufacturing method.
The method of claim 5,
The step of preparing the Mo mixed powder includes mixing a molybdenum (Mo) powder having an average particle diameter of 3 to 5 µm and a carbon powder having an average particle diameter of 2 to 3 µm. Manufacturing method.
The method of claim 5,
In the step of preparing the Mo mixed powder, the powder is dried at 110 to 130° C. and then the particle size is selected into 300 to 350 mesh.
The method of claim 5,
In the step of preparing the MoCu heat dissipating material, the copper is infiltrated at a temperature of 1350 to 1450° C. in a hydrogen reducing atmosphere.

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