KR20140103479A - Metal-ceramic laminar composites and the manufacturing method of the same - Google Patents

Abstract

The present invention relates to a metal-ceramic layered composite material and a method for manufacturing the same and, more particularly, to a method for manufacturing a metal-ceramic layered composite material including a step for simultaneously surface-treating a metal and ceramic, which are bonding targets, in a vacuum chamber by using plasma; and a step for bonding the metal and the ceramic during the surface treatment process, in which the surface treatment and the bonding are performed at room temperature, and a metal-ceramic layered composite material manufactured by using the manufacturing method described above. According to the present invention, surfaces of the metal and the ceramic, which constitute the composite material, are cleaned and activated by using the plasma in a high-vacuum state, and thus foreign matters generated on the surfaces can be easily removed. Also, the possibility of foreign matter growth, in which the foreign matters are nuclei, is extremely low. Accordingly, the manufactured composite material can be uniform in material properties and improved in performance.

Description

Technical Field [0001] The present invention relates to a metal-ceramic layered composite material and a method of manufacturing the same.

The present invention relates to a metal-ceramic layered composite material and a method of manufacturing the same, and more particularly, to a metal-ceramic layered composite material which comprises a step of simultaneously treating a metal and a ceramic to be bonded to each other in a vacuum chamber using plasma, A method of manufacturing a metal-ceramic layered composite material, comprising the steps of: bonding a metal and a ceramic to each other, wherein the surface treatment and bonding are performed at room temperature; and forming a metal-ceramic layered composite material to provide.

With the development of the IT industry, production of LED products is increasing, and it is also very encouraging that LED products are getting higher output. However, as the LED product becomes higher in power, the energy value required for driving increases, and this energy value generates heat load to the product. In particular, the development trend of LED products is as high as that of prototypes up to about 10W, and the heat load generated by them is increasing greatly. However, such heat load affects the physical properties and performance of the product and its parts, and is a negative factor in the life of the product unless it is solved.

In order to buffer the thermal load of such a high-output LED product, a heat dissipating means is required, and a heat spreader having a heat dissipating function has been developed in parallel. In LED products, the heat spreader is attached to the areas where the heat is most generated among the LED products to disperse the heat and protect the LED package from the heat.

Conventional heat spreaders are metal / polymer insulation layers / metal structures, for example, Cu / polymer insulation layer / Al products have been mainly produced. However, the polymer serving as an insulator has a merit that the manufacturing process is simple, and the unit cost of the product is lowered and high-speed mass production is possible. However, since the thermal conductivity is very low (~ 1 W / mK) .

For example, a ceramic alumina (Al ₂ O ₃ ) insulating layer has a very high thermal conductivity (about 20 W / mK) than the polymer insulating layer ), It exhibits superior heat dissipation characteristics as compared with the Al / polymer insulation layer / Cu heat spreader, and can be a positive factor for the lifetime or performance of the LED product.

As a conventional method for forming such a ceramic insulating layer, there is AAO (Anodic Aluminum Oxide) method, which is a method of forming an aluminum surface by alumina by anodizing aluminum, and the process is simple , It is difficult to control the alumina form, and there is a problem that the alumina destruction phenomenon may occur depending on the withstand voltage characteristic.

In addition, there is a brazing method in which a brazing material is used as an adhesive at the junction of a metal and a ceramic, and the adhesive is heated and melted to be bonded. Since the process is carried out at a high temperature, There is a concern about the change of physical properties.

In addition, the solid phase diffusion bonding method can be applied, which is a method of bonding by pressurization at a high temperature without melting ceramics and metals. Since the high pressure is used as well as the high temperature process as in the brazing method, There is a possibility that deformation and physical property change may occur.

A sputtering method can be used, which is a method of forming a thin metal layer on a ceramic substrate with one of vapor deposition junctions, and a sputter for performing sputtering is a very expensive equipment, The deposition rate is slow, and the target must be continuously replaced, resulting in an additional cost.

On the other hand, in Korean Patent Laid-Open Publication No. 2001-0071232 entitled " Method of manufacturing a metal foil / ceramic bonding material and a metal foil laminated ceramic substrate ", a metal foil and a ceramic are respectively referred to as ions and a technique of bonding a metal foil and a ceramic by separately heating a ceramic after ion etching There is a superiority that no damage is caused to the bonded body due to the absence of pressure, but there is a time interval between the bonding processes after the surface treatment, and in particular, The activated surface is left in the chamber and the surface active state thereof is slowed down.

In addition, since the rollers are used when pressurizing, there is a sequential non-uniformity of the pressure between the portion contacting the roller and the portion not contacting the roller, and it is necessary to control the thickness of the roller according to the thickness of the material. .

Further, since the surface of the ceramic is heated, in some cases, a difference in thermal expansion coefficient between the materials may become more problematic, whereby unnecessary stress may act on the material in the joining region of the joining material or its adjacent region, Deformed or broken.

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a method of cleaning a surface of metal and ceramics using plasma in a high vacuum state, The present invention aims to homogenize the physical properties of the composite material to be produced and to improve the performance thereof.

In addition, since the present invention does not require thickness control between materials required when joining by vapor deposition or the like, it can be widely applied irrespective of the thickness of the material, .

Another object of the present invention is to improve the reliability of a product to which the present invention is applied since it is a process that proceeds under a normal temperature and a low pressure so that the area of deformation and damage remaining in the composite material to be produced is very small.

In addition, since the present invention does not apply a heating means or a heating method in the bonding process, there is very little room for grain coarsening and interfacial diffusion, and thus the basic characteristics of a composite material, such as thermal conductivity characteristics, And it is another object of the present invention to ensure durability more than adequate.

Further, the present invention is also applicable to a method of manufacturing a metal or metal oxide film by oxygen existing in a chamber despite the vacuum, due to the time interval interposed between the surface treatment process and the bonding process, by performing the interlayer bonding process immediately after the surface treatment process or the surface treatment process Another object of the present invention is to manufacture an interlaminar composite material having excellent bonding strength by performing a bonding process in a state where the surface activity is maximized by eliminating the problem that the activated surface of the ceramic is oxidized to return to the state before the surface treatment.

In addition, since the present invention uses a process of pressing the entire stage without using a roller during the pressing process, it is possible to apply a uniform pressure to the material during the bonding process, thereby ensuring uniformity and durability of the bonded state For another purpose. That is, the entire surface of the bonded metal and ceramics is pressed uniformly at a time, so that there is no possibility of deformation or breakage of the material during the joining process of the material.

The present invention also relates to a method for manufacturing a bonded material having excellent bonding strength even though a separate energy consumption process such as heating is performed to maintain the surface treatment state because the bonding process of the material is performed during or immediately after the surface treatment process For another purpose.

In order to achieve the above-mentioned object, the present invention provides a method of manufacturing a semiconductor device, comprising the steps of: simultaneously treating a metal and a ceramic to be bonded with a plasma in a vacuum chamber; And bonding the metal and the ceramic in the process of the surface treatment. The present invention also provides a method of manufacturing a metal-ceramic layered composite material.

Preferably, the metal is an aluminum (Al) thin plate, and the ceramic is alumina (Al ₂ O ₃ ).

The initial vacuum degree for maintaining the vacuum in the vacuum chamber is preferably at least 10 ^-7 Torr.

The atmosphere for generating the plasma in the vacuum chamber is preferably an argon (Ar) atmosphere.

The degree of vacuum of the vacuum chamber at the time of plasma generation is preferably at least 10 ^-4 Torr.

The metal-ceramic layered composite material is preferably Al / Al ₂ O ₃ / Cu.

The joining method in the joining step is preferably HV-SCDB (High Vacuum Surface Controlled Direct Bonding), and it is preferable to simultaneously press the entire surface of the metal and the ceramic.

The upper pressing means and the lower pressing means are hinged to each other. Metal, ceramic, ceramic and metal are respectively seated on the lower surface of the upper pressing means and the upper surface of the lower pressing means. The upper pressing means is hinged At least two pressing pieces connected to the pressing device are provided at the upper part of the upper pressing device so that a uniform pressure is applied through the pressing of the metal and the ceramic through the pressing piece .

The step of bonding the metal and the ceramics during the surface treatment is preferably performed at room temperature.

Time of the surface treatment is preferably 10 to 200 seconds is the case of Al is 10 to 120 seconds, the case of Al ₂ O _3.

It is preferable that the applied electric power is 30 to 100 W when the plasma is generated.

The power is 60 W, and it is preferable to perform the surface treatment for 40 seconds at this time, and the highest bonding strength is shown at this time.

The pressing time at the time of bonding is preferably at least 5 minutes.

The present invention also provides a method of manufacturing a semiconductor device, comprising the steps of: simultaneously treating a metal and a ceramic to be bonded with a plasma in a vacuum chamber; Immediately after the surface treatment is performed, successively joining the metal and the ceramic; Wherein each of the steps is performed at room temperature, and the bonding step is started within a range of 0 to 1 minute or less after the surface treatment.

The present invention also provides a metal-ceramic layered composite material which is produced by the above-described method.

As described above, according to the present invention, since the surfaces of metal and ceramics, which are composites composites, are cleaned and activated by using plasma in a high vacuum state, it is easy to remove foreign substances generated on the surface thereof, It is anticipated that the effect of homogenizing the physical properties of the composite material to be produced and improving the performance thereof is expected.

In addition, since the present invention does not require thickness control between materials necessary for bonding by vapor deposition or the like, it can be widely applied irrespective of the thickness of the material, It is expected.

In addition, since the present invention is a process that proceeds under normal temperature and low pressure, the range of deformation and damage remaining in the composite material to be produced is very small, so that it is expected to enhance the reliability of the product to which it is applied.

Further, by performing the interlayer bonding process immediately after the surface treatment process or the surface treatment process, due to the temporal interval interposed between the surface treatment process and the bonding process, the activation of the metal or ceramics by the oxygen existing in the chamber, It is possible to obtain an interlayer composite material having excellent bonding strength by performing the bonding process in a state where the surface activity is maximized by eliminating the problem that the surface of the surface is oxidized to return to the state before the surface treatment.

In addition, since the present invention utilizes a process of pressing the entire stage without using a roller during the pressing process, uniform pressure can be applied to the material during the bonding process, thereby ensuring uniformity and durability of the bonded state The effect is expected.

In addition, since the present invention performs a bonding process of a material during or immediately after a surface treatment process, it does not require additional energy consumption such as heating to maintain the surface treatment condition, The effect is expected.

1 is a process diagram illustrating a surface activation bonding process according to an embodiment of the present invention.
FIG. 2 is a view showing a process of bonding Al and Al ₂ O ₃ using the apparatus of FIG. 1, wherein (a) shows a surface treatment step by plasma, and (b) will be.
Fig. 3 is a view showing a pressurizing means according to an embodiment of the present invention, wherein (a) shows a state before pressurization, (b) shows a pressurized state, and (c) before pressurization.
4 is a graph showing changes in the contact angle of (a) Al and (b) Al ₂ O ₃ according to the applied power and surface treatment time in the surface treatment according to an embodiment of the present invention.
5 is a microstructure photograph showing the interface between Al and Al ₂ O ₃ bonded according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings and preferred embodiments.

The present invention is to produce a metal-ceramic composite material by joining metal and ceramics using a HV-SCDB (High Vacuum Surface Controlled Direct Bonding) method different from the conventional vapor deposition method and mechanical bonding method.

In the present invention, various metals and ceramics can be bonded by the surface activation bonding method. In the present invention, Al and Al ₂ O ₃ are selected as the metal and the ceramic, respectively. Hereinafter, explanation will be made on the assumption that the metal is Al and the ceramic is Al ₂ O ₃ .

The method of producing the Al-Al ₂ O ₃ precision layered composite material of the present invention uses a surface activated bonding, and the basic principle of the bonding is that the surface of the material is subjected to surface treatment using a plasma without external heat treatment in a vacuum chamber, The surface of the specimen is converted into an activated state.

It is the basic principle of the surface activation bonding that the two specimens after surface treatment are bonded and the two specimens are bonded under pressure. When applying pressure, when the conventional mechanical joining method exerts a high pressure in tonnes, the present invention applies a low pressure of 0.18 to 0.47 Kgf / cm ² , which is much lower than that of the conventional mechanical joining method, It is possible to prevent deformation or breakage of the battery.

<Production Example>

A method of manufacturing an Al-Al ₂ O ₃ composite material according to an embodiment of the present invention is as follows.

First, according to one embodiment of the present invention, an apparatus necessary for plasma application and bonding by pressurization to a bonded object is used, and a bonding unit inside the chamber of the apparatus is provided with Al and Al ₂ O _{3 Place the} specimen (S11). Thereafter, plasma is irradiated to the bonded object to be bonded, and the surface of the bonded object is subjected to surface treatment (S12). Next, the bonded bodies are directly joined together by lamination at the same time as the surface treatment or immediately after the surface treatment without intervention of another process (S13). The graft means the stage prior to bonding by pressurization. Thereafter, pressure is applied to the bonded object to be bonded to bond the bonded object (S14). This completes the process according to one embodiment of the present invention. Such a process flow is shown in Fig.

As shown in FIG. 2 (a), a specimen to be bonded is placed on a bonding unit provided in the chamber, and a vacuum pump is used to make the inside of the chamber high-vacuum. At this time, the initial vacuum degree is maintained at 10 ^-7 Torr or more. This is to ensure a necessary degree of vacuum (10 ^-4 Torr or more) for generating an ion plasma in an argon (Ar) gas atmosphere, which is a plasma source. If the initial degree of vacuum is less than the above value, plasma is not generated properly. Here, as the atmospheric gas, an inert gas other than argon gas may be used instead.

That is, by giving after securing the initial degree of vacuum, on condition that at least 10 ^-4 Torr to obtain a vacuum degree under flowing inert gas, argon gas as the plasma source, as above, starting the ion gun (Gun Ion) Al and Al ₂ O _{3 The} specimen is cleaned and surface treated at the same time. It is possible to remove the foreign substances and the oxide layer remaining on the surface of the metal and the ceramic in the surface treatment process.

Then, as shown in Fig. 2 (b), the two surface-treated specimens are pressure bonded. At this time, the range of the pressing force is preferably 0.18 to 0.47 Kgf / cm ² as described above. In the case of 0.47 Kg / cm ² in the above range, it is possible to maintain a proper pressing force while avoiding deformation and breakage of the base material. In the case of less than the lower limit of the upper range, there is a fear of deformation and breakage, but the bonding force is insufficient, There is a risk of deformation or breakage of the base material. Therefore, the pressure range has its critical significance in the upper range.

2 and 3, the pressurizing process is performed by pressing the pressing means 10 and 20 so as to press the metal 30 and the entire ceramic 40 So that unevenness due to the local position of the metal 30 and the ceramic 40 surface is not generated after the pressing process or the pressing process.

Two pressing pieces 50 and 60 are provided on the pressing units 10 and 20 and the two pressing pieces 50 and 60 are connected to a pressing device Uniform pressures are applied to the respective pressing pieces 50 and 60, so that uniform pressing can be performed more than when pressing is performed with only one pressing part.

Two or more of the above pressure pieces may be provided, such as three or four pressure pieces.

On the other hand, the upper pressurizing means 10 and 20 are configured to pivot about the hinge. On the lower surface of the upper pressurizing means 20 and the upper surface of the lower pressurizing means 10 of the pressurizing means, The upper pressurizing means 20 is pivoted to be seated on the lower pressurizing means 10 so that the respective materials to be bonded 30 and 40 are adjacent to each other, By applying pressure to the upper pressing pieces 50 and 60, the pressing process is completed (Fig. 3 (b)).

The upper pressurizing means is advantageous also in the plasma processing. The surface of the material placed on the upper pressurizing means 20 and the lower pressurizing means 10 can be subjected to plasma treatment simultaneously using the plasma processing apparatus 70 (See FIG. 3 (c)). Since the upper pressing means 20 can be rotated and seated on the lower pressing means 10 during or immediately after the plasma processing, the temporal gap existing between the plasma processing process and the pressing process There is an advantage in that the bonding can be performed in a state in which the surface active state of the materials 30 and 40 to be bonded is maintained to the maximum.

It is preferable that the surface treatment process continues to the process of joining the above specimens in the bonding unit.

However, the surface treatment process and the bonding process may intermittently occur as in the case of bonding after the surface treatment. However, from the viewpoint of maintaining the activated state of the surface until bonding, the surface treatment process It would be more desirable to do so.

In the present invention, the heating means from the surface treatment to the bonding of the metal and the ceramic is not used at all, because sufficient activity can be imparted without heating in the process of imparting the activity to the surface of the specimen so as to increase the bonding force, Therefore, since the diffusion layer at the interface is very small as compared with the conventional high-temperature process, the inherent characteristics of the material can be maintained.

On the other hand, composite materials according to the present invention may be used as LED heat spreader for being manufactured in Examples Al / Al ₂ O ₃ / Cu days, possible examples other applications, where the bonding technique of Cu and Al ₂ O ₃ addition, the present invention Since a technique using a high vacuum plasma such as that described above can be applied, a detailed description will be omitted.

FIG. 4 is a graph showing changes in the contact angle depending on the surface treatment time and the power applied during the surface treatment in the surface treatment of Al and Al ₂ O ₃ according to an embodiment of the present invention.

Here, FIG. 4 (a) is a graph for Al and FIG. 4 (b) is a graph for Al ₂ O ₃ .

As shown in the figure, before the surface treatment, it is understood that the contact angle is very large for both substrates so that the bonding is unfavorable.

The concept of the contact angle can be obtained by measuring the angle formed between the plane and the droplet at the interface when the droplet is dripped on the plane. As the droplet is not wetted well on the plane, the contact angle becomes larger and the droplet does not form the shape. When wetted and flat, the contact angle is small. As such a concept, two substrates having a large contact angle are difficult to be bonded to each other, and two substrates having a small contact angle are easily bonded to each other.

The contact angle generally tends to decrease with the time of the surface treatment. However, when the electric power of 70 W is applied, the surface treatment time is 120 seconds (in case of Al) or 200 seconds (in case of Al ₂ O ₃ ) It was found that the contact angle was rather increased.

Therefore, the appropriate surface treatment time is preferably 120 seconds or less in the case of Al and 200 seconds or less in the case of Al ₂ O ₃ , preferably 10 to 120 seconds in the case of Al and 10-200 seconds in the case of Al ₂ O ₃ good. Considering the contact angle, it is more preferable to set the upper limit value to 100 seconds. In addition, the applied power is preferably 30 to 100 W, and preferably 30 to 60 W. When the surface treatment time or the applied power is out of the range, it is difficult to expect an improvement in the contact angle, so that the above numerical ranges have a critical significance in the range. Although the result is not shown separately, when the surface treatment was performed at a voltage of 60 W for 40 seconds, the highest bonding force of 0.5 N / m ² was exhibited. However, a commercially available bonding force can be derived from the applied power range of the above range, and the above applied power range has its critical meaning in that respect.

On the other hand, the pressing time in the bonding process after the surface treatment is preferably at least 5 minutes, and a bonding force capable of commercialization can be secured.

In addition, it is preferable that the temporal interval between the start of the bonding process after the surface treatment, which is a characteristic process variable disclosed in the present invention, is within a range of more than 0 minutes and not more than 1 minute, to be.

5 is a microstructure photograph showing the interface between Al and Al ₂ O ₃ bonded according to an embodiment of the present invention.

As shown in the figure, the interface between Al and Al ₂ O ₃ forms a flat surface, and no deformation occurs at the interface, and since Al is not heated, diffusion of Al to Al ₂ O ₃ does not occur, It can be seen that the physical properties can be maintained. As a result of the surface treatment, it was found that the bonding state was very good even though the substrate was not pressed or heated at a high pressure.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, something to do.

10: lower pressing means 20: upper pressing means
30: metal 40: ceramic
50, 60: pressing piece 70: plasma processing device

Claims (15)

Simultaneously subjecting the metal and the ceramic to be bonded to each other using a plasma in a vacuum chamber;
Bonding the metal and the ceramic during the surface treatment;
Wherein the metal-ceramic layered composite material is a metal-ceramic layered composite material. The method according to claim 1,
Wherein the metal is an aluminum (Al) thin plate, and the ceramic is alumina (Al ₂ O ₃ ). The method according to claim 1,
Wherein the initial vacuum for maintaining a vacuum in the vacuum chamber is at least 10 &lt; ^-7 &gt; Torr. The method according to claim 1,
Wherein the atmosphere for generating the plasma in the vacuum chamber is an argon (Ar) atmosphere. 5. The method of claim 4,
Wherein the degree of vacuum of the vacuum chamber during plasma generation is at least 10 &lt; ^-4 &gt; Torr. The method according to claim 1,
Wherein the metal-ceramic layered composite material is Al / Al ₂ O ₃ / Cu. The method according to claim 1,
Wherein the bonding step in the joining step is a HV-SCDB (High Vacuum Surface Controlled Direct Bonding) method, wherein the entire surface of the metal and the ceramic is simultaneously pressed. 8. The method of claim 7,
The pressing means is hinged to the upper pressing means and the lower pressing means,
A metal, ceramic, ceramic, and metal are respectively seated on the lower surface of the upper pressing means and the upper surface of the lower pressing means,
Wherein the upper pressing means is hingedly coupled to the lower pressing means to be pressed,
Wherein at least two pressing pieces connected to the pressing device are provided on the upper pressing means to apply a uniform pressure to the metal and the ceramic through the pressing force applied to the metal and the ceramic through the pressing piece. Way. The method according to claim 1,
The method of manufacturing a metal-ceramic layered composite material according to claim 1, wherein the step of bonding the metal and the ceramic during the surface treatment is performed at room temperature. The method according to claim 1,
Wherein the time of the surface treatment is 10 to 120 seconds in the case of Al and 10 to 200 seconds in the case of Al ₂ O ₃ . The method according to claim 1,
Wherein the applied electric power is 30 to 100 W when the plasma is generated. 12. The method of claim 11,
Wherein the electric power is 60 W, and when the surface treatment is performed for 40 seconds, the highest bonding strength is exhibited. The method according to claim 1,
Wherein the pressing time at the joining is at least 5 minutes. Simultaneously subjecting the metal and the ceramic to be bonded to each other using a plasma in a vacuum chamber;
Immediately after the surface treatment is performed, successively joining the metal and the ceramic;
Wherein each of the steps is performed at room temperature, and the bonding step starts within a range of more than 0 minutes and less than 1 minute after the surface treatment. A metal-ceramic layered composite material produced by the method of any one of claims 1 to 14.

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