JP2002237557A - Copper plate laminated heat sink and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a copper plate laminated heat sink which can make heat dissipation effect, even on the surface of a copper plate and can further increase the heat dissipation performance. SOLUTION: The method of manufacturing a copper plate laminated heat sink comprises a solder plating layer formation process, wherein a base plate 11 and the copper plate 2 are dipped in molten solder and then are applied with ultrasonic vibrations, to form a compound layer 31 comprising a solder component and an aluminum component and a solder plating layer 331 on the surface of the base plate 11 and to form a compound layer 32, comprising a solder component and a copper component and a solder plating layer 332 on the surface of the copper plate 2; a heating process of heating the solder plating layers 331 and 332 so that they turn into a molten state; a pressurization process of abutting via the solder plating layers 331 and 332 in a molten state against each other and then pressurizing them; and a cooling process of cooling the solder plating layers 331 and 332 in a pressurized state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper plate laminated heat sink in which a copper plate is surface-bonded to the surface of a base plate of a heat sink by soldering, and a method of manufacturing the same. The heat sink includes a plate fin type and a pin fin type.

[0002]

2. Description of the Related Art As shown in FIG.
In the heat sink 10 of an aluminum integral body, which is an integral body of
In some cases, a sufficient heat radiation effect cannot be expected. Therefore, in recent years, a copper plate laminated heat sink 101 in which the copper plate 2 is laminated on the surface of the base plate 11 of the heat sink 10 by soldering has been developed as shown in FIG. According to the copper-plate laminated heat sink 101, copper having about twice the thermal conductivity of aluminum is bonded to the surface of the base plate 11, so that a high heat radiation effect can be expected.

[0003] The copper-plate laminated heat sink 101 has been manufactured as follows. That is, the surface of the base plate 11 is coated with solder, and the copper plate 2 is
The surfaces are brought into contact and pressurized while heating both.

[0004]

However, in the copper-plate laminated heat sink 101, the solder layer 3 formed between the base plate 11 and the copper plate 2 due to the application of the solder, as shown in the enlarged view of FIG. In addition, the thickness was uneven. The thermal conductivity from the copper plate to the base plate in the copper laminate heat sink changes in accordance with the thickness of the solder layer. The heat conductivity increases as the thickness of the solder layer decreases, and decreases as the thickness of the solder layer increases.
In No. 01, the heat radiation effect on the surface of the copper plate 2 was not uniform.

Further, in the above-described manufacturing method, since only pressure is applied while heating, the bonding strength between the solder layer 3 and each surface of the base plate 11 and the copper plate 2 is not sufficient, and therefore, the heat radiation effect is improved. Even had limitations.

[0006] The present invention provides a copper plate laminated heat sink capable of making the heat radiation effect uniform on the surface of the copper plate and further improving the heat radiation effect, and provides a method of manufacturing such a copper plate laminated heat sink. That is the purpose.

[0007]

According to the first aspect of the present invention,
A copper plate laminated heat sink, in which a copper plate is surface-bonded by soldering to a surface of a base plate of a heat sink made of an aluminum member, wherein a solder layer between the base plate and the copper plate has a uniform thickness, The present invention is characterized in that a compound layer composed of a solder component and an aluminum component is present at an interface portion between the solder layer and the surface of the base plate.

According to a second aspect of the present invention, in the first aspect of the present invention, a compound layer composed of a solder component and a copper component is present at an interface between the solder layer and the surface of the copper plate. It is.

According to a third aspect of the present invention, there is provided a method of manufacturing a copper plate laminated heat sink by bonding a copper plate to a surface of a base plate of a heat sink made of an aluminum member by soldering. By immersing and applying ultrasonic vibration,
Forming a compound layer composed of a solder component and an aluminum component on the surface of the base plate and a solder plating layer adhered through the compound layer; and heating the solder plating layer to a molten state. Heating step, press the copper plate in contact with the surface of the base plate through the molten solder plating layer and pressurize, pressurizing step, and cooling the solder plating layer while maintaining the pressurized state, cooling step And having the following.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a copper-plate laminated heat sink by bonding a copper plate to a surface of a base plate of a heat sink made of an aluminum member by soldering. Dipping and applying ultrasonic vibration to form a compound layer composed of a solder component and a copper component and a solder plating layer adhered through the compound layer on the surface of the copper plate, a solder plating layer forming step; Heating the solder plating layer to be in a molten state, a heating step, and pressing the copper plate in contact with the surface of the base plate through the molten solder plating layer, and pressing, and the pressing step remains in the pressed state. And a cooling step of cooling the solder plating layer.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a copper-plate laminated heat sink by bonding a copper plate to a surface of a base plate of a heat sink made of an aluminum member by soldering. By immersing it in and applying ultrasonic vibration, a compound layer composed of a solder component and an aluminum component and a solder plating layer adhered through the compound layer are formed on the surface of the base plate, and the surface of the copper plate is formed. Forming a compound layer composed of a solder component and a copper component and a solder plating layer adhered through the compound layer, and heating both solder plating layers to a molten state. , A heating step, and press contact with both via a solder plating layer in a molten state,
It is characterized by having a pressurizing step and a cooling step of cooling the solder plating layer while keeping the pressurized state.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In these drawings, the thicknesses of a solder layer, a compound layer, and a solder plating layer are exaggerated. I have.

FIG. 1 is a longitudinal sectional view of a copper plate heat sink of the present invention. In this copper plate laminated heat sink 1, the copper plate 2 is surface-bonded to the surface of the base plate 11 of the heat sink 10 made of aluminum in one piece by soldering. The heat sink 10 includes a base plate 11 and a large number of fins 1.
2 and an aluminum member. The aluminum member is aluminum or an aluminum alloy. The fins 12 are plate fins, but may be pin fins.

[0014] Between the base plate 11 and the copper plate 2,
A solder layer 3 is present. The solder layer 3 includes a compound layer 31 existing at an interface with the surface of the base plate 11;
It comprises a compound layer 32 present at the interface with the surface of the copper plate 2 and a solder body layer 33 present between the two compound layers 31, 32. The compound layer 31 is composed of a compound composed of a solder component and an aluminum component, and the compound layer 32 is composed of a compound composed of a solder component and a copper component. The solder body layer 33 is made of a solder component. The solder layer 3 has a uniform thickness.

The copper-plate laminated heat sink 1 having the above structure is manufactured as follows. First, as shown in FIG. 2, the surface of the base plate 11 of the heat sink 10 is immersed in the molten solder 30, and ultrasonic vibration is applied to the heat sink 10 or the solder bath 4 through an appropriate horn. As the solder 30, for example, Zn-5% Al which is a solder for an aluminum member is used. Its melting point is 380 ° C. The frequency of the ultrasonic wave is about 17.6 KHz. Cavitation occurs by applying ultrasonic vibration.
At this time, the following reaction occurs. That is, at the interface between the surface of the base plate 11 and the solder 30, a layer made of an intermetallic compound and an oxide is formed, and this layer is peeled off by cavitation caused by ultrasonic vibration. While the aluminum component in the inside removes oxygen from the oxide on the surface of the base plate 11, the solder 3
Spreading into zero. Thereby, the base plate 11
The surface is activated and the solder 30 is wetted, and as shown in FIG. 3, a compound layer 31 made of a compound composed of the component of the solder 30 and the aluminum component is formed, and the compound layer 31 forms a layer on the surface of the base plate 11. The firmly adhered solder plating layer 331 is formed. Moreover, since the solder 30 uniformly contacts the surface of the base plate 11, the compound layer 31 and the solder plating layer 331 are formed with a uniform thickness.

On the other hand, as shown in FIG. 4, the copper plate 2 is processed in the same manner as the above-mentioned base plate 11. That is, the copper plate 2
Is immersed in the molten solder 30 and ultrasonic vibration is applied to the copper plate 2 or the solder bath 4 through a suitable horn. Thereby, the same reaction as in the case of the base plate 11 described above occurs. That is, a layer made of an intermetallic compound and an oxide is formed at the interface between the surface of the copper plate 2 and the solder 30, and this layer is peeled off by cavitation caused by ultrasonic vibration. The copper component therein diffuses into the solder 30 while removing oxygen from the oxide on the surface of the copper plate 2. As a result, the surface of the copper plate 2 is activated and the solder 30 is wetted, as shown in FIG.
A compound layer 32 made of a compound consisting of the component of the solder 30 and the copper component is formed, and the compound layer 32 forms a solder plating layer 332 firmly attached to the surface of the copper plate 2. In addition, since the solder 30 contacts the surface of the copper plate 2 evenly, the compound layer 32 and the solder plating layer 332 are formed.
Are formed with a uniform thickness.

It is preferable that the heat sink 10 or the copper plate 2 be preheated before being immersed in the molten solder 30. The preheating temperature is, for example, 400 ° C. in the above case.
If preheated, the formation of both compound layers 31, 32 and both solder plating layers 331, 332 will be performed well.

Next, as shown in FIG. 6, in a state where the solder plating layer 331 of the base plate 11 and the solder plating layer 332 of the copper plate 2 are in contact with each other, heat is applied to both to melt them. That is, while the heat sink 10 is held by the metal comb-shaped jig 5, the base plate 11 is heated by transmitting heat from the heater 61 to the jig 5 to melt the solder plating layer 331, and the copper plate 2 The solder plating layer 33 is heated by the heater 62.
2 is melted. This melting operation may be performed in a state where the solder plating layer 331 and the solder plating layer 332 are not in contact with each other.

Next, as shown in FIG. 7, the molten solder plating layer 331 of the heat sink 10 held by the jig 5 and the molten solder plating layer 332 of the copper plate 2 are brought into contact with each other. Sandwiched between the upper mold 71 and the lower mold 72,
Pressure is applied so that the base plate 11 and the copper plate 2 are pressed against each other. Thus, the solder plating layer 331 and the solder plating layer 332 are mixed while flowing out partly to the surroundings, and become one layer. At this time, both solder plating layers 3
31 and 332 are formed by using the same solder 30 and therefore exhibit self-solubility, and therefore mix with each other without hindrance.

Then, while maintaining the pressurized state shown in FIG.
The two solder plating layers 331 and 332 are cooled to room temperature. The cooling means is preferably air cooling (radial cooling), but may be water cooling or the like. Thus, the two solder plating layers 331 and 332 become a single solder body layer 33, the solder layer 3 is obtained, and the copper-plate laminated heat sink 1 having the configuration of FIG. 1 is obtained.

According to the above-described manufacturing method, the compound layer 31, the compound layer 32, the solder plating layer 331, and the solder plating layer 332 are each formed with a uniform thickness, so that the solder layer 3 is also formed with a uniform thickness. Is done. Therefore, in the obtained copper-plate laminated heat sink 1, the copper plate 2 is joined to the surface of the base plate 11 by the solder layer 3 having a uniform thickness.

The solder plating layer 331 is formed of the compound layer 3
1 and the solder plating layer 332 is obtained by firmly adhering to the surface of the copper plate 2 by the compound layer 32, so that the solder body layer 33 is obtained by firmly adhering to the surface of the copper plate 2 by the compound layer 32. Are obtained by firmly adhering to both. In addition, since the two solder plating layers 331 and 332 are cooled to room temperature while being pressed, the solder body layer 33 is peeled off due to a difference in thermal expansion between aluminum and copper during solidification. Is prevented. Therefore, in the obtained copper-plate laminated heat sink 1, the solder layer 3 is adhered to the surface of the base plate 11 and the surface of the copper plate 2 with sufficient strength.
The copper plate 2 is bonded to the surface of the base plate 1 with sufficient strength.

According to the copper plate laminated heat sink 1 having the above structure, since the solder layer 3 has a uniform thickness, the copper plate 2
The thermal conductivity from the surface of the copper plate 2 to the base plate 11 through the solder layer 3 is the same. Therefore,
The heat radiation effect on the surface of the copper plate 2 can be made uniform.

Moreover, since the copper plate 2 and the base plate 11 are joined with sufficient strength by the solder layer 3 including both compound layers 31 and 32, the thermal conductivity from the copper plate 2 to the base plate 11 via the solder layer 3 is low. Has improved.

In the above manufacturing method, the solder plating layer 331 and the solder plating layer 332 are formed using the same solder 30, but they may be formed using different solders. However, in that case, both solder plating layers 331, 3
It is necessary to use a solder made of a material in which 32 exhibits self-solubility.

In the above-described manufacturing method, the step of forming the solder plating layer 331 on the base plate 11 or the step of forming the solder plating layer 332 on the copper plate 2 is performed as follows.
Either one may be omitted.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Copper-plate laminated heat sink 1 of the present invention (FIG. 1)
And a conventional aluminum heat sink 10 (FIG. 9)
And a conventional copper plate laminated heat sink 101 (FIG. 10). Table 1 shows the specific dimensions of the various heat sinks. W, H, T1, and T2 in the table are shown in FIG. 1, FIG. 9, and FIG. L is the length in the direction perpendicular to W. In addition, in the copper-plate laminated heat sink 1 of the present invention, the thickness of the solder layer 3 was about 10 μm, and the pressing condition was extrusion of 30 tons. Further, in the conventional copper-plate laminated heat sink 101, the thickness of the solder layer 3 was about 80 μm, and the pressing condition was a 30 kg press.

[0028]

[Table 1]

Table 2 shows the thermal resistance indicating the heat radiation effect, which is the performance of the various heat sinks.

[0030]

[Table 2]

[Thermal Resistance] The thermal resistance was determined as follows. That is, as shown in FIG. 8, a target heat sink X is installed in a duct 81, a heater 82 assuming an object to be cooled is attached to a base plate, wind is sent from the front in the direction of arrow A, and heat input from the heater 82 is performed. The maximum temperature of the heat sink on the surface of the base plate, the ambient temperature at the entrance of the duct 81, and the power consumption of the heater 82 (that is, the amount of heat input) are measured and calculated according to Equation 1. 83 is a slider for setting the power consumption of the heater 82, 84 is an ammeter, 85 is a voltmeter, 8
6 is a hybrid recorder for measuring each of the above temperatures, 8
7 is a fan. Therefore, the thermal resistance is the temperature rise per watt, and the heat sink has higher performance as the thermal resistance is lower. Here, the wind speed from the front is set variously and measured.

[0032]

(Equation 1)

As can be seen from Table 2, the copper-plate laminated heat sink 1 of the present invention has a lower thermal resistance than the conventional heat sinks 10 and 101, and has high performance.

[0034]

According to the first aspect of the present invention, since the solder layer has a uniform thickness, the thermal conductivity from the copper plate to the base plate via the solder layer can be reduced at all points on the surface of the copper plate. The heat radiation effect on the surface of the copper plate can be made uniform.

Moreover, since the solder layer can be firmly adhered to the base plate surface by the compound layer,
The copper plate and the base plate can be joined with sufficient strength, and therefore, the thermal conductivity from the copper plate to the base plate via the solder layer can be improved.

According to the second aspect of the present invention, the solder layer can be firmly attached to the surface of the copper plate by the compound layer, so that the copper plate and the base plate can be joined with more sufficient strength. Thermal conductivity from the copper plate to the base plate via the solder layer can be further improved.

According to the third aspect of the present invention, since the solder plating layer is formed by applying ultrasonic vibration, the compound layer and the solder plating layer can be formed with a uniform thickness on the surface of the base plate. Therefore, a copper plate laminated heat sink in which the copper plate is joined to the base plate surface by the solder layer having a uniform thickness can be obtained.

Further, since the solder plating layer is formed by applying ultrasonic vibration, the solder plating layer can be obtained by firmly adhering to the surface of the base plate via the compound layer. In addition, since the solder plating layer is cooled to room temperature while being pressurized, it is possible to prevent the solder plating layer from peeling off due to a difference in thermal expansion between aluminum and copper during solidification. Therefore, the solder layer can be firmly attached to the surface of the base plate, and therefore, a copper plate laminated heat sink in which the copper plate is firmly joined to the surface of the base plate by the solder layer can be obtained.

According to the fourth aspect of the present invention, the ultrasonic plating is applied to form the solder plating layer.
The compound layer and the solder plating layer can be formed with a uniform thickness. Therefore, a copper plate laminated heat sink in which the copper plate is joined to the base plate surface by the solder layer having a uniform thickness can be obtained.

Since the solder plating layer is formed by applying ultrasonic vibration, the solder plating layer can be firmly attached to the surface of the copper plate via the compound layer. Moreover,
Since the solder plating layer is cooled to room temperature while maintaining the pressurized state, it is possible to prevent the solder plating layer from warping.
Therefore, the solder layer can be firmly adhered to the surface of the copper plate, and therefore, a copper plate laminated heat sink in which the copper plate is firmly joined to the surface of the base plate by the solder layer can be obtained.

According to the fifth aspect of the present invention, since the solder plating layer is formed by applying ultrasonic vibration, the compound layer and the solder plating layer can be formed on the surfaces of the base plate and the copper plate, respectively, with a uniform thickness. . Therefore, a copper plate laminated heat sink in which the copper plate is joined to the base plate surface by the solder layer having a uniform thickness can be obtained.

Further, since the solder plating layer is formed by applying ultrasonic vibration, the solder plating layer can be firmly attached to the surfaces of the base plate and the copper plate via the compound layer, respectively. In addition, since the solder plating layer is cooled to room temperature while being in a pressurized state, warpage of the solder plating layer can be prevented. Therefore, the solder layer can be firmly adhered to the surfaces of the base plate and the copper plate, respectively. Therefore, a copper plate laminated heat sink in which the copper plate is more firmly joined to the base plate surface by the solder layer can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a copper plate laminated heat sink of the present invention.

FIG. 2 is a longitudinal sectional view showing one step of the manufacturing method of the present invention.

FIG. 3 is a longitudinal sectional view showing a step following FIG. 2;

FIG. 4 is a longitudinal sectional view showing another step of the manufacturing method of the present invention.

FIG. 5 is a longitudinal sectional view showing a step following FIG. 4;

FIG. 6 is a longitudinal sectional view showing a further subsequent step of the manufacturing method of the present invention.

FIG. 7 is a vertical sectional view showing a step following FIG. 6;

FIG. 8 is a schematic diagram showing an outline of an apparatus for measuring thermal resistance.

FIG. 9 is a longitudinal sectional view of a conventional heat sink made of aluminum.

FIG. 10 is a longitudinal sectional view of a conventional copper-plate laminated heat sink.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copper-plate laminated heat sink 10 Heat sink (of aluminum one body) 11 Base plate 2 Copper plate 3 Solder layer 30 Solder 31, 32 Compound layer 331, 332 Solder plating layer

Claims (5)

[Claims] A copper plate laminated heat sink, wherein a copper plate is surface-bonded to a surface of a base plate of a heat sink made of an aluminum member by soldering, wherein a solder layer between the base plate and the copper plate has a uniform thickness. In the interface part of the solder layer with the surface of the base plate,
A copper-plate laminated heat sink comprising a compound layer comprising a solder component and an aluminum component. 2. The heat sink according to claim 1, wherein a compound layer composed of a solder component and a copper component is present at an interface portion of the solder layer with the surface of the copper plate. 3. A method of manufacturing a copper plate laminated heat sink by bonding a copper plate to a surface of a base plate of a heat sink made of an aluminum member by soldering, wherein the base plate is immersed in molten solder and ultrasonically vibrated. Forming a compound layer composed of a solder component and an aluminum component on the surface of the base plate and a solder plating layer adhered via the compound layer, and melting the solder plating layer. A heating step, and a pressing step, in which a copper plate is brought into contact with the surface of the base plate through the molten solder plating layer to pressurize the solder plating layer. A method for manufacturing a copper-plate laminated heat sink, comprising: cooling and cooling. 4. A method for manufacturing a copper plate laminated heat sink by bonding a copper plate to a surface of a base plate of a heat sink made of an aluminum member by soldering, wherein the copper plate is immersed in molten solder and subjected to ultrasonic vibration. Forming a compound layer comprising a solder component and a copper component and a solder plating layer adhered through the compound layer on the surface of the copper plate by adding a solder plating layer, and melting the solder plating layer. A heating step, and a pressing step, in which a copper plate is brought into contact with the surface of the base plate through the molten solder plating layer to pressurize the solder plating layer. A method for manufacturing a copper-plate laminated heat sink, comprising: cooling and cooling. 5. A method for manufacturing a copper-plate laminated heat sink by bonding a copper plate to a surface of a base plate of a heat sink made of an aluminum member by soldering, wherein the base plate and the copper plate are immersed in molten solder, and By applying sonic vibration, a compound layer composed of a solder component and an aluminum component and a solder plating layer adhered through the compound layer are formed on the surface of the base plate, and the solder component is formed on the surface of the copper plate. Forming a compound layer composed of a copper component and a solder plating layer adhered through the compound layer, a solder plating layer forming step, and heating both solder plating layers to be in a molten state;
A heating step, and a pressing step in which both are brought into contact with each other via a molten solder plating layer to press the solder plating layer, and a cooling step in which the solder plating layer is cooled while the pressing state is maintained. Method for manufacturing a copper plate laminated heat sink.