KR101774586B1 - Manufacturing method of substrate for power module equiptted with heat sink, substrate for power module equiptted with heat sink, and power module - Google Patents

Manufacturing method of substrate for power module equiptted with heat sink, substrate for power module equiptted with heat sink, and power module Download PDF

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KR101774586B1
KR101774586B1 KR1020110019479A KR20110019479A KR101774586B1 KR 101774586 B1 KR101774586 B1 KR 101774586B1 KR 1020110019479 A KR1020110019479 A KR 1020110019479A KR 20110019479 A KR20110019479 A KR 20110019479A KR 101774586 B1 KR101774586 B1 KR 101774586B1
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heat sink
metal plate
metal
substrate
layer
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KR20120021154A (en
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히로시 도노무라
요시유키 나가토모
요시로우 구로미츠
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미쓰비시 마테리알 가부시키가이샤
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H01L2224/321—Disposition
    • H01L2224/32151—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/32221—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/32225—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation

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  • Microelectronics & Electronic Packaging (AREA)
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  • Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
  • Chemical & Material Sciences (AREA)
  • Power Engineering (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
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Abstract

[PROBLEMS] To provide a method of manufacturing a substrate for a power module with a heat sink capable of firmly bonding a heat sink and a second metal plate by suppressing the occurrence of voids at a bonding interface between the heat sink and the second metal plate.
[MEANS FOR SOLVING PROBLEMS] A heat sink joining step for joining a heat sink to the other surface of a second metal plate includes a Si layer forming step (S01) in which a Si layer is formed on at least one of joining surfaces of the other surface of the second metal sheet and the heat sink, (S02) for laminating a second metal plate and a heat sink through a Si layer, pressing the second metal plate and the heat sink in a lamination direction and heating the Si, A heat sink heating step (S03) for forming a molten metal region by diffusing the molten metal into the melt, and a molten metal solidifying step (S04) for joining the second metal plate and the heat sink by solidifying the molten metal region.

Description

TECHNICAL FIELD [0001] The present invention relates to a substrate for a power module with a heat sink, a substrate for a power module with a heat sink, and a power module,

The present invention relates to a method of manufacturing a substrate for a power module with a heat sink, a substrate for a power module with a heat sink, and a power module used in a semiconductor device for controlling high current and high voltage.

Among the semiconductor devices, power devices for power supply have a relatively high heating value. Therefore, as a substrate on which the power devices are mounted, a substrate made of Al (aluminum nitride) or Si 3 N 4 (silicon nitride) ) And a heat sink are connected to the opposite side of the substrate with a second metal plate made of Al (aluminum) interposed therebetween.

In such a substrate for a power module with a heat sink, the first metal plate is formed as a circuit layer, and the semiconductor chip of the power element is mounted on the first metal plate with a solder material interposed therebetween.

Conventionally, the above-described substrate for a power module with a heat sink is manufactured in the following order, for example, as described in Patent Document 1.

First, a first metal plate is laminated on one surface of a ceramic substrate through a brazing material, a second metal plate is laminated on the other surface of the ceramic substrate with a brazing material interposed therebetween, and this is pressed in a lamination direction at a predetermined pressure And the ceramic substrate and the first metal plate and the second metal plate are bonded to each other by heating (ceramics substrate bonding step).

Next, a heat sink is laminated on the surface of the second metal plate opposite to the ceramic substrate with a brazing material interposed therebetween. The heat sink is pressurized with a predetermined pressure in the lamination direction and heated, whereby the second metal plate and the heat sink are bonded (Heat sink bonding step).

Japanese Patent Application Laid-Open No. 2002-009212

In the heat sink joining step of joining the heat sink and the second metal plate, in the case where a brazing filler metal is used, at the interface portion between the second metal plate and the heat sink, the surface of the second metal plate and the heat sink, There is an oxide film on the surface of the oxide film, and the total thickness of the oxide film tends to be thick. Here, when bonding the second metal plate and the heat sink, the heat sink and the second metal plate (substrate for power module) were pressurized with sufficient pressure in the lamination direction and subjected to heat treatment in order to remove these oxide films. However, the oxide film could not be removed at the portion where the pressure was insufficient, and voids were locally generated at the bonding interface between the heat sink and the second metal plate.

Particularly, in recent years, it has been proposed to mount a plurality of semiconductor elements on a single board for a power module, and the junction area between the heat sink and the second metal plate tends to become larger, and the risk of the above- .

Further, when soldering the second metal plate and the heat sink, a solder foil of an Al-Si based alloy containing Si at 7.5% by mass or more is often used in order to set the melting point to a low value. As described above, in an Al-Si based alloy containing a relatively large amount of Si, it is difficult to produce a laminated body by rolling or the like due to insufficient ductility.

In addition, a brazing material foil is disposed between the heat sink and the second metal plate and heated by pressing them in the laminating direction. The brazing material foil, the heat sink and the second metal plate are laminated I needed to do it.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and it is an object of the present invention to suppress the occurrence of voids at the bonding interface between the heat sink and the second metal plate to firmly bond the heat sink and the second metal plate, A method of manufacturing a substrate for a power module with a heat sink capable of providing a substrate for an attached power module and a substrate and a power module for a power module with a heat sink obtained by the method.

A method of manufacturing a substrate for a power module with a heat sink according to the present invention includes a ceramic substrate, a first metal plate made of aluminum on one surface thereof bonded to the surface of the ceramics substrate, A second metal plate made of aluminum having one surface bonded to the back surface of the ceramic substrate and a heat sink having a heat sink made of aluminum or an aluminum alloy bonded to the other surface opposite to the one surface of the second metal plate bonded to the ceramics substrate, A method of manufacturing a substrate for a power module with a sink, comprising the steps of: joining a ceramics substrate, the first metal plate, and the ceramics substrate to the second metal plate; And the heat sink joining step A Si layer forming step of fixing Si to at least one of the other surface of the second metal plate and the bonding surface of the heat sink to form a Si layer; and a step of laminating the second metal plate and the heat sink through the Si layer A heat sink heating step of pressing and heating the stacked second metal plate and the heat sink in a stacking direction to form a molten metal region at an interface between the second metal plate and the heat sink; And a molten metal solidification step of solidifying the molten metal region to bond the second metal plate and the heat sink, wherein in the heat sink heating step, Si of the Si layer is diffused into the second metal plate and the heat sink And the molten metal region is formed at the interface between the second metal plate and the heat sink.

In the method of manufacturing a substrate for a power module with a heat sink with this structure, a heat sink joining step for joining a heat sink to the other surface of the second metal plate is performed by joining at least one of the joining surfaces of the other surface of the second metal plate and the heat sink Si is formed by bonding the Si to form a Si layer. Therefore, Si is interposed at the bonding interface between the second metal plate and the heat sink. Here, since the Si is an element for lowering the melting point of aluminum, a molten metal region can be formed at the interface between the second metal plate and the heat sink even if the temperature is relatively low.

Further, in the heating step, the molten metal region is formed at the interface between the heat sink and the second metal plate by diffusing Si in the Si layer toward the second metal plate and the heat sink, and by solidifying the molten metal region, The second metal plate and the heat sink are bonded to each other. Therefore, it is not necessary to use an Al-Si based brazing filler metal or the like.

Since the Si is fixed directly to the second metal plate and the heat sink, the oxide film is formed only on the surface of the second metal plate and the heat sink, and the total thickness of the oxide film existing at the interface between the second metal plate and the heat sink Is thinner than when a brazing filler metal is used. Therefore, it is possible to reliably remove the oxide film at the time of bonding, suppressing the generation of voids at the bonding interface between the second metal plate and the heat sink, and improving the bonding strength between the second metal plate and the heat sink .

In addition, as described above, since the second metal plate and the heat sink are bonded to each other without using an Al-Si based brazing foil or the like, which is difficult to manufacture, the second metal plate and the heat sink can be securely bonded A substrate for a power module with a heat sink can be manufactured.

In addition, since Si is directly fixed to at least one of the bonding surface of the heat sink and the other surface of the second metal plate without using a brazing filler metal, it is not necessary to perform the alignment work of the brazing filler metal.

In the Si layer forming step, at least one of Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li is added to at least one of the other surface of the second metal plate and the bonding surface of the heat sink. It is preferable to fix one or two or more additional elements.

In this case, one or two or more additional elements selected from Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li are added to Si at the bonding interface between the second metal plate and the heat sink. Here, elements such as Cu, Zn, Ge, Ag, Mg, Ca, Ga and Li are elements that lower the melting point of aluminum. Therefore, under the relatively low temperature conditions, A molten metal region can be formed.

Therefore, even if the joining is performed under the joining conditions of relatively low temperature and short time, the second metal plate and the heat sink can be bonded more firmly.

In addition, in the Si layer forming step, it is preferable that Al is fixed together with Si.

In this case, Al is adhered together with Si, so that the formed Si layer contains Al. In the heating step, the Si layer is preferentially melted and a molten metal region is formed at the interface between the second metal plate and the heat sink So that the second metal plate and the heat sink can be firmly joined. Further, in order to fix Al together with Si, Si and Al may be deposited at the same time, or may be sputtered using an alloy of Si and Al as a target. Si and Al may be laminated.

The ceramics substrate bonding step may include bonding at least one of Cu or Si to at least one of a bonding surface of the ceramics substrate and a bonding surface of the first metal plate at a bonding interface between the ceramics substrate and the first metal plate And at least one of Cu or Si is formed on at least one of a bonding surface of the ceramics substrate and a bonding surface of the second metal plate at a bonding interface between the ceramics substrate and the second metal plate And a second metal layer formed on the ceramics substrate and the second metal plate, and a metal fixing step of bonding the ceramic substrate and the first metal plate to each other via the first metal layer, And a step of pressing the first metal plate, the ceramic substrate and the second metal plate stacked in the lamination direction A ceramic substrate heating step of forming a first molten metal region and a second molten metal region at an interface between the first metal plate and the ceramics substrate and an interface between the ceramic substrate and the second metal plate; 1) a first molten metal and a second molten metal solidification step for solidifying the molten metal region and the second molten metal region to join the first metal plate, the ceramics substrate and the ceramics substrate to the second metal plate, In the substrate heating step, at least one of Cu and Si of the first metal layer and the second metal layer is diffused into the first metal plate and the second metal plate so that the interface between the first metal plate and the ceramic substrate and the ceramics A first molten metal region and a second molten metal region are formed at an interface between the substrate and the second metal plate, As it may be.

In this case, it is no longer necessary to use a brazing material for bonding the ceramics substrate and the first metal plate, and also for bonding the ceramics substrate and the second metal plate, and the ceramics substrate and the first metal plate and the second metal plate can be reliably bonded at low cost .

In addition, since at least one of Si and Cu is interposed at the bonding interface between the ceramic substrate and the first metal plate and the second metal plate, the ceramic substrate and the metal plate can be firmly bonded even if they are bonded under a relatively short time of bonding.

In the metal fixing step, at least one of a bonding surface of the ceramics substrate and a bonding surface of the first metal plate on a bonding interface between the ceramics substrate and the first metal plate, or a bonding surface of the ceramics substrate and the first metal plate, Ge, Ag, Mg, Ca, Ga, and Li on at least one of the bonding surface of the ceramic substrate and the bonding surface of the second metal plate at the bonding interface of the first metal plate, It is preferable to fix one or more selected additional elements.

In this case, Zn, Ge, Ag, Mg, Ca, Ga, or a combination of at least one of Cu or Si is formed on the bonding interface between the ceramics substrate and the first metal plate or the bonding interface between the ceramic substrate and the second metal plate And Li is interposed between one or more of the additive elements. Here, elements such as Zn, Ge, Ag, Mg, Ca, Ga and Li are elements which lower the melting point of aluminum. Therefore, under the relatively low temperature condition, It is possible to reliably form the molten metal region or the second molten metal region at the interface between the ceramics substrate and the second metal plate.

Therefore, even if bonding is performed under the bonding conditions of relatively low temperature and short time, the ceramics substrate and the first metal plate and the second metal plate can be bonded more firmly.

In addition, it is preferable that the ceramics substrate bonding step and the heat sink bonding step are simultaneously performed.

In this case, by performing the ceramics substrate bonding step and the heat sink bonding step at the same time, the cost for joining can be greatly reduced. In addition, since it is completed without repeated heating and cooling, it is possible to reduce warpage of the board for power module with this heat sink.

The Si layer forming step may be performed by plating, vapor deposition, CVD, sputtering, cold spray, or by spraying a paste or ink in which powder is dispersed, at least one of the bonding surfaces of the heat sink and the other surfaces of the second metal plate It is preferable to fix Si on one side.

In this case, it is preferable that Si is coated on at least one of the bonding surface of the heat sink and the other surface of the second metal plate by plating, vapor deposition, CVD, sputtering, cold spray, or application of paste or ink in which the powder is dispersed So that Si can be surely interposed at the bonding interface between the heat sink and the second metal plate. Further, the fixing amount of Si can be adjusted with high precision, the molten metal region can be surely formed, and the heat sink can be strongly bonded to the second metal plate.

It is preferable that the second metal plate is formed by stacking a plurality of metal plates.

In this case, since the second metal plate has a structure in which a plurality of metal plates are stacked, thermal deformation due to the difference in thermal expansion coefficient between the heat sink and the ceramic substrate can be sufficiently alleviated by the second metal plate, The occurrence of cracks can be suppressed.

A substrate for a power module with a heat sink according to the present invention comprises a ceramic substrate, a first metal plate having one surface bonded to the surface of the ceramics substrate, and a second metal plate And a heat sink made of aluminum or an aluminum alloy bonded to the other surface of the second metal plate opposite to the one surface bonded to the ceramics substrate, wherein Si is solid-dissolved in the second metal plate and the heat sink, And the Si concentration in the vicinity of the bonding interface of the second metal plate and the heat sink is set within a range of 0.05 mass% or more and 0.6 mass% or less.

According to the substrate for a power module with a heat sink with this structure, Si is solidified in each of the second metal plate and the heat sink, so that the bonding interface side portions of the second metal plate and the heat sink are strengthened by employment.

Here, since the Si concentration in the vicinity of the bonding interface between the second metal plate and the heat sink is 0.05 mass% or more, the bonding interface side portion of the second metal plate and the heat sink can be surely strengthened by employment . In addition, since the Si concentration in the vicinity of the bonding interface between the second metal plate and the heat sink is 0.6 mass% or less, it is possible to prevent the strength of the bonding interface between the second metal plate and the heat sink from excessively increasing , And the thermal deformation can be absorbed by the second metal plate and the heat sink.

It is preferable that one or more additional elements selected from Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li in addition to Si are dissolved in the second metal plate and the heat sink.

In this case, since one or more additional elements selected from Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li in addition to Si are dissolved in the second metal plate and the heat sink, 2 metal plate and the bonding interface side portion of the heat sink can be surely hardened and strengthened.

In addition, at least one of Cu and Si, at least one of Zn, Ge, Ag, Mg, Ca, and Ca is present near the bonding interface between the first metal plate and the ceramics substrate, or near the bonding interface between the second metal plate and the ceramic substrate. , Ga and Li are preferably dissolved in one or more of the following elements.

In this case, at least one of Cu or Si, Zn, Ge, Ag, Mg, Ca, and Ca are formed in the vicinity of the bonding interface between the first metal plate and the ceramics substrate or near the bonding interface between the second metal plate and the ceramic substrate. , Ga and Li are dissolved in the first metal plate and the second metal plate, the bonding interface side portion of the first metal plate and the second metal plate bonded to the ceramics substrate can reliably be solid-solved.

It is preferable that the thickness of the second metal plate is set to be larger than the thickness of the first metal plate.

In this case, the rigidity on the side where the heat sink is formed can be made higher than the rigidity on the opposite side, thereby suppressing the warp after cooling.

It is preferable that the second metal plate is formed by stacking a plurality of metal plates.

In this case, since the second metal plate has a structure in which a plurality of metal plates are stacked, thermal deformation due to the difference in thermal expansion coefficient between the heat sink and the ceramic substrate can be sufficiently alleviated by the second metal plate, The occurrence of cracks can be suppressed.

The power module of the present invention is characterized by including the above-described substrate for a power module with a heat sink and an electronic component mounted on the substrate for the power module with the heat sink.

According to the power module of this configuration, even when the bonding strength between the heat sink and the second metal plate is high and the use environment is difficult, heat from electronic components such as semiconductor devices can be dissipated.

According to the present invention, it is possible to provide a board for a power module with a high-quality heat sink, which can firmly bond the heat sink and the second metal plate by suppressing the occurrence of voids at the bonding interface between the heat sink and the second metal plate A method of manufacturing a substrate for a power module with a heat sink, and a substrate and a power module for a power module with a heat sink obtained by the manufacturing method.

1 is a schematic explanatory diagram of a power module using a substrate for a power module with a heat sink which is the first embodiment of the present invention.
Fig. 2 is an explanatory view showing a Si concentration distribution of a metal layer and a heat sink of a substrate for a power module with a heat sink according to the first embodiment of the present invention. Fig.
3 is a flowchart of a method of manufacturing a substrate for a power module with a heat sink according to the first embodiment of the present invention.
4 is an explanatory view showing a manufacturing method of a substrate for a power module with a heat sink which is the first embodiment of the present invention.
Fig. 5 is an explanatory view showing the vicinity of the joint interface between the second metal plate (metal layer) and the heat sink shown in Fig. 4;
6 is a schematic explanatory diagram of a power module using a substrate for a power module with a heat sink according to a second embodiment of the present invention.
7 is an explanatory view showing a Si concentration distribution and a Ge concentration distribution of a metal layer and a heat sink of a substrate for a power module with a heat sink which is a second embodiment of the present invention.
8 is a flowchart of a method of manufacturing a substrate for a power module with a heat sink according to a second embodiment of the present invention.
9 is an explanatory view showing a manufacturing method of a substrate for a power module with a heat sink which is a second embodiment of the present invention.
10 is a schematic explanatory view of a power module using a substrate for a power module with a heat sink according to a third embodiment of the present invention.
11 is an explanatory view showing a Si concentration distribution and an Ag concentration distribution in a metal layer and a heat sink of a substrate for a power module with a heat sink according to the third embodiment of the present invention.
12 is a flowchart of a manufacturing method of a substrate for a power module with a heat sink according to a third embodiment of the present invention.
13 is an explanatory view showing a manufacturing method of a substrate for a power module with a heat sink which is a third embodiment of the present invention.
14 is an explanatory view showing a manufacturing method of a substrate for a power module with a heat sink which is the third embodiment of the present invention.
15 is a schematic explanatory view of a power module using a substrate for a power module with a heat sink, which is a fourth embodiment of the present invention.
16 is a flowchart of a manufacturing method of a substrate for a power module with a heat sink according to a fourth embodiment of the present invention.
17 is an explanatory view showing a manufacturing method of a substrate for a power module with a heat sink which is a fourth embodiment of the present invention.
18 is an explanatory view showing a manufacturing method of a substrate for a power module with a heat sink which is a fourth embodiment of the present invention.
19 is a schematic explanatory view of a power module using a substrate for a power module with a heat sink, which is another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 shows a substrate for a power module with a heat sink and a power module according to a first embodiment of the present invention.

The power module 1 includes a power module substrate 10 on which a circuit layer 12 is formed, a semiconductor chip 3 bonded to the surface of the circuit layer 12 via a solder layer 2, And a heat sink (40). Here, the solder layer 2 is made of a Sn-Ag based, Sn-In based, or Sn-Ag-Cu based soldering material, for example. In the present embodiment, a Ni plating layer (not shown) is formed between the circuit layer 12 and the solder layer 2.

The substrate 10 for a power module includes a ceramic substrate 11, a circuit layer 12 formed on one surface (upper surface in Fig. 1) of the ceramic substrate 11, And a metal layer 13 disposed on the surface (lower surface in Fig. 1).

The ceramic substrate 11 prevents electrical connection between the circuit layer 12 and the metal layer 13, and is made of AlN (aluminum nitride) having high insulating properties. The thickness of the ceramic substrate 11 is set within a range of 0.2 to 1.5 mm, and is set to 0.635 mm in the present embodiment. 1, the width of the ceramic substrate 11 is set wider than the width of the circuit layer 12 and the metal layer 13. In this embodiment,

The circuit layer 12 is formed by bonding a conductive metal plate 22 to one surface of a ceramic substrate 11. In the present embodiment, the circuit layer 12 is formed by bonding a metal plate 22 made of aluminum (so-called 4N aluminum) rolling plate having a purity of 99.99% or more to the ceramics substrate 11.

The metal layer 13 is formed by joining a metal plate 23 to the other surface of the ceramics substrate 11. In this embodiment, the metal layer 13 is formed by bonding a metal plate 23 made of a rolled plate of aluminum (so-called 4N aluminum) having a purity of 99.99% or more to the ceramics substrate 11, similarly to the circuit layer 12 .

The heat sink 40 is for cooling the above-described substrate 10 for a power module and includes a top plate 41 to be bonded to the substrate 10 for power module, And a flow path 42 for discharging the fluid. The heat sink 40 (the top plate portion 41) is preferably made of a material having good thermal conductivity, and in the present embodiment, it is made of A6063 (aluminum alloy).

2, the metal layer 13 (the metal plate 23) and the heat sink 40 are bonded to each other at the bonding interface 30 between the metal layer 13 (the metal plate 23) and the heat sink 40, Si is solid-solubilized. Concentration gradient layers 33 and 34 are formed in the vicinity of the bonding interface 30 of the metal layer 13 and the heat sink 40 so as to gradually decrease in Si concentration as they are separated from the bonding interface 30 in the stacking direction . The Si concentration in the bonding interface 30 side (in the vicinity of the bonding interface 30 of the metal layer 13 and the heat sink 40) of the concentration gradient layers 33 and 34 is not less than 0.05 mass% and not more than 0.6 mass% .

The concentration of Si in the vicinity of the bonding interface 30 of the metal layer 13 and the heat sink 40 was measured by EPMA analysis (spot diameter 30 占 퐉) at five points at a position of 50 占 퐉 from the bonding interface 30 to be. 2 shows a line analysis in the lamination direction at the center of the width of the metal layer 13 (metal plate 23) and the heat sink 40 (top plate portion 41) And the concentration at the site.

Hereinafter, a method for manufacturing a substrate for a power module with a heat sink having the above-described configuration will be described with reference to FIGS. 3 to 5. FIG.

(Si layer forming step (S01) / Si fixing step (S11))

First, as shown in Figs. 4 and 5, a first Si layer 24 is formed by fixing Si on one surface of a metal plate 22 serving as a circuit layer 12 by sputtering, and a metal layer 13 (Si bonding step (S11)). The second Si layer (25) is formed by sputtering Si on one surface of the metal plate (23).

Si is fixed to the other surface of the metal plate 23 as the metal layer 13 by sputtering to form the Si layer 26 (Si layer forming step (S01)).

Here, in this embodiment, the amount of Si in the first Si layer 24, the second Si layer 25, and the Si layer 26 is set to 0.002 mg / cm 2 or more and 1.2 mg / cm 2 or less.

 (Heat sink laminating step (S02) / ceramics substrate laminating step (S12))

Next, as shown in Fig. 4, the metal plate 22 is laminated on one side of the ceramic substrate 11, and the metal plate 23 is laminated on the other side of the ceramics substrate 11 Laminating step S12). 4, the first Si layer 24 of the metal plate 22 and the second Si layer 25 of the metal plate 23 are formed on the surface of the ceramic substrate 11 so as to face the ceramics substrate 11, , 23 are laminated.

Further, the heat sink 40 is laminated on the other surface side of the metal plate 23 (heat sink laminating step (S02)). At this time, the metal plate 23 and the heat sink 40 are laminated so that the surface of the metal plate 23 on which the Si layer 26 is formed faces the heat sink 40, as shown in Fig.

That is, the first Si layer 24 and the second Si layer 25 are interposed between the metal plates 22 and 23 and the ceramic substrate 11, respectively, and the Si layer 24 is formed between the metal plate 23 and the heat sink 40, (26).

(Heat sink heating step (S03) / ceramics substrate heating step (S13))

Next, the metal plate 22, the ceramics substrate 11, the metal plate 23, and the heat sink 40 are charged in a vacuum heating furnace in a state of being pressed (pressure of 1 to 35 kgf / cm2) And the first molten metal region 27 and the second molten metal region 28 are formed at the interface between the metal plates 22 and 23 and the ceramics substrate 11 in the ceramic substrate heating step S13.

At the same time, a molten metal region 29 is formed between the metal plate 23 and the heat sink 40 (heat sink heating step (S03)).

5, the Si of the Si layer 26 diffuses toward the metal plate 23 side and the heat sink 40 side as shown in Fig. 5, so that the Si layer 26 of the metal plate 23 and the heat sink 40 And the Si concentration in the vicinity of the silicon substrate 26 increases to lower the melting point.

When the pressure is less than 1 kgf / cm 2, it is impossible to satisfactorily bond the ceramics substrate 11 to the metal plates 22 and 23 and to bond the metal plate 23 and the heat sink 40 There is a concern. If the above-described pressure exceeds 35 kgf / cm 2, the metal plates 22 and 23 and the heat sink 40 may be deformed. Therefore, it is preferable that the above-described pressure is in the range of 1 to 35 kgf / cm 2.

Here, in the present embodiment, the pressure in the vacuum furnace is set in the range of 10 -6 Pa or more and 10 -3 Pa or less, and the heating temperature is set in the range of 600 ° C or more and 650 ° C or less.

(Molten metal solidification step (S04) / first molten metal and second molten metal solidification step (S14))

Next, the temperature is kept constant while the molten metal region 29 is formed. Then, the Si in the molten metal region 29 is further diffused toward the metal plate 23 side and the heat sink 40 side. As a result, the Si concentration in the portion which has been the molten metal region 29 is gradually lowered, the melting point is raised, and the solidification progresses while maintaining the temperature constant. In other words, the heat sink 40 and the metal plate 23 are bonded by so-called Transient Liquid Phase Diffusion Bonding. After solidification proceeds in this way, cooling is carried out to room temperature.

Similarly, Si in the first molten metal region 27 and the second molten metal region 28 is diffused toward the metal plates 22 and 23 side. As a result, the Si concentration in the portion which was the first molten metal region 27 and the second molten metal region 28 is gradually lowered and the melting point is raised, and the solidification progresses while maintaining the temperature constant. Thus, the ceramics substrate 11 and the metal plates 22 and 23 are bonded.

The metal plates 22 and 23 as the circuit layer 12 and the metal layer 13 are bonded to the ceramics substrate 11 and the metal plate 23 and the heat sink 40 are joined together, A substrate for a power module with a heat sink is manufactured.

In the power module with a heat sink and the power module 1 according to the present embodiment having the above-described configuration, the Si layer 26 is provided between the metal plate 23 serving as the metal layer 13 and the heat sink 40 (Si) is formed on the bonding interface 30 between the metal plate 23 and the heat sink 40. In this case, Here, since Si is an element for lowering the melting point of aluminum, the molten metal region 29 can be reliably formed at the interface between the metal plate 23 and the heat sink 40, even at a relatively low temperature.

The molten metal region 29 is formed by diffusing Si of the Si layer 26 formed on the other surface of the metal plate 23 toward the metal plate 23 side and the heat sink 40 side in the heat sink heating step (S03) The Si in the molten metal region 29 is further solidified by diffusing the Si in the molten metal solidification step (S04) toward the metal plate 23 side and the heat sink 40 side so that the heat sink 40 and the metal layer 13 Metal plate 23) are bonded to each other, it is not necessary to use an Al-Si-based brazing foil or the like.

The oxide film is formed on the surface of the metal layer 13 (the metal plate 23) and the heat sink 40 (the top plate portion 41) because Si is directly fixed to the metal layer 13 The total thickness of the oxide film existing at the interface between the metal layer 13 (the metal plate 23) and the heat sink 40 (the top plate portion 41) becomes thinner than in the case of using a brazing filler metal. This makes it possible to reliably remove the oxide film and suppress generation of voids at the bonding interface 30 with the metal layer 13 (metal plate 23) and the heat sink 40 (top plate portion 41) It is possible to improve the bonding strength between the metal layer 13 (the metal plate 23) and the heat sink 40 (the top plate portion 41).

In this embodiment, the ceramics substrate 11, the circuit layer 12 (the metal plate 22), and the metal layer 13 (the metal plate 23) The first Si layer 24 formed on the joining surface of the first molten metal region 27 and the second molten metal region 27 is formed by diffusing the Si of the second Si layer 25 toward the metal plates 22, Si in the first molten metal region 27 and the second molten metal region 28 are further joined to the metal plates 22 and 23 in the first molten metal and the second molten metal solidifying step S14, The ceramic substrate 11 and the circuit layer 12 (the metal plate 22) and the metal layer 13 (the metal plate 23) are bonded to each other. The metal layer 13 and the metal layer 23 are formed on the bonding interface of the layer 12 (the metal plate 22) and the bonding interface of the ceramic substrate 11 and the metal layer 13 The total thickness of the film becomes thin and the yield of the initial bonding of the ceramics substrate 11 and the circuit layer 12 (the metal plate 22) and the ceramic substrate 11 and the metal layer 13 (the metal plate 23) .

Since the brazing material is not used for joining the heat sink 40 and the metal plate 23 and for joining the ceramics substrate 11 and the metal plates 22 and 23, The heat sink 40 and the metal plate 23 and the ceramic substrate 11 and the metal plates 22 and 23 can be bonded to each other with certainty. Therefore, the board for the power module with the heat sink of the present embodiment can be produced efficiently at low cost.

In the present embodiment, since the ceramic substrate 11 and the metal plates 22 and 23 are bonded together and the metal plate 23 and the heat sink 40 are bonded together at the same time, Can be reduced. Moreover, since the ceramics substrate 11 is completed without repeated heating and cooling, it is possible to reduce the warpage of the substrate for the power module with the heat sink and to produce the substrate for the power module with the high-quality heat sink .

In the Si layer forming step S01, Si is fixed on the other surface of the metal plate 23 by sputtering to form the Si layer 26, so that the heat sink 40 is formed between the heat sink 40 and the metal plate 23 Si can be surely interposed. Further, the amount of Si adhering can be adjusted with high accuracy, and the molten metal region 29 can be surely formed, and the metal plate 23 can be firmly bonded to the heat sink 40.

In the substrate for a power module with a heat sink according to the present embodiment, the metal layer 13 (the metal plate 23) is provided at the bonding interface 30 between the heat sink 40 and the metal layer 13 (metal plate 23) ) And the heat sink 40 are made of Si and the Si concentration on the bonding interface 30 side of each of the metal layer 13 and the heat sink 40 is set within the range of 0.05 mass% to 0.6 mass% The portion of the metal layer 13 (the metal plate 23) and the portion of the heat sink 40 on the bonding interface 30 side is solid-solved and the metal layer 13 (metal plate 23) and the heat sink 40 It is possible to prevent the occurrence of cracks. Therefore, it is possible to provide a substrate for a power module with a highly reliable heat sink.

Next, a substrate for a power module with a heat sink and a power module according to a second embodiment of the present invention will be described with reference to Figs. 6 to 9. Fig.

The power module 101 includes a power module substrate 110 on which a circuit layer 112 is formed, a semiconductor chip 3 bonded to the surface of the circuit layer 112 via a solder layer 2, And a heat sink 140 are provided.

The substrate 110 for a power module includes a ceramic substrate 111, a circuit layer 112 formed on one surface (upper surface in Fig. 6) of the ceramics substrate 11, And a metal layer 113 formed on the surface of the substrate (lower surface in Fig. 6).

In addition, the ceramic substrate 111 is made of AlN (aluminum nitride) having high insulation property.

The circuit layer 112 is formed by bonding a metal plate 122 made of a rolled plate of aluminum (so-called 4N aluminum) having a purity of 99.99% or more to the ceramics substrate 111.

The metal layer 113 is formed by bonding a metal plate 123 made of a rolled plate of aluminum (so-called 4 N aluminum) having a purity of 99.99% or more to the ceramics substrate 111, like the circuit layer 112.

6, the thickness of the metal layer 113 is set to be larger than the thickness of the circuit layer 112. In this embodiment,

The heat sink 140 is for cooling the above-described power module substrate 110 and includes a top plate 141 bonded to the power module substrate 110, a flow path 142 for flowing the cooling medium, . The heat sink 140 (the top plate portion 141) is preferably made of a material having good thermal conductivity, and in the present embodiment, it is made of A6063 (aluminum alloy).

7, the metal layer 113 (the metal plate 123) and the heat sink 140 are bonded to each other at the bonding interface 130 between the metal layer 113 (the metal plate 123) and the heat sink 140, One or two or more additional elements selected from Cu, Zn, Ge, Ag, Mg, Ca, Ga and Li are added to Si. In this embodiment, Ge is employed as an additional element.

In addition, in addition to Si, at the bonded interface between the circuit layer 112 (metal plate 122) and the ceramics substrate 111 and the bonded interface between the metal layer 113 (metal plate 123) and the ceramics substrate 111, Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li. In this embodiment, Ge is employed as an additional element.

Here, the concentration gradient layers 133, 133 are formed in the vicinity of the bonding interface 130 of the metal layer 113 and the heat sink 140 so that the Si concentration and the Ge concentration gradually decrease as they are separated from the bonding interface 130 in the stacking direction. 134 are formed. Here, Si and additional elements (Ge in the present embodiment) on the bonding interface 130 side of the concentration gradient layers 133 and 134 (near the bonding interface 130 of the metal layer 113 and the heat sink 140) Is set within a range of 0.05 mass% or more and 6.5 mass% or less.

The Si concentration and the Ge concentration in the vicinity of the bonding interface 130 of the metal layer 113 and the heat sink 140 were measured at five points at a position of 50 占 퐉 from the bonding interface 130 by EPMA analysis (spot diameter 30 占 퐉) It is an average. The graph of FIG. 7 shows a line analysis in the lamination direction at the center of the width of the metal layer 113 (metal plate 123) and the heat sink 140 (top plate portion 141) And the concentration at the site.

Hereinafter, a method for manufacturing a substrate for a power module with the above-described structure with a heat sink will be described with reference to Figs. 8 and 9. Fig.

(Si bonding step (S101))

9, a first Si layer 124 is formed by fixing Si to one surface of a metal plate 122 serving as a circuit layer 112 by sputtering, and at the same time, Si is fixed to one surface of the metal plate 123 by sputtering to form the second Si layer 125. [ The first Si layer 124 and the second Si layer 125 may contain at least one additive element selected from Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li in addition to Si And Ge is used as an additive element in the present embodiment.

(Ceramic substrate laminating step (S102))

Next, the metal plate 122 is laminated on one surface side of the ceramics substrate 111, and the metal plate 123 is laminated on the other surface side of the ceramics substrate 111. At this time, the metal plates 122 and 123 are laminated so that the first Si layer 124 of the metal plate 122 and the second Si layer 125 of the metal plate 123 are formed to face the ceramics substrate 111.

(Ceramic substrate heating step (S103))

Next, the metal plates 122 and 123, the ceramic substrate 111 and the metal plate 123 are charged into the vacuum furnace under the pressure (pressure 1 to 35 kgf / cm2) in the stacking direction and heated, A first molten metal region and a second molten metal region are formed at the interface between the first molten metal region and the ceramic substrate 111, respectively.

Here, in the present embodiment, the pressure in the vacuum furnace is set in the range of 10 -6 Pa or more and 10 -3 Pa or less, and the heating temperature is set in the range of 600 ° C or more and 650 ° C or less.

(The first molten metal and the second molten metal solidification step (S104)),

Next, the temperature in the state where the first molten metal region and the second molten metal region are formed is kept constant, and Si in the first molten metal region and the second molten metal region is diffused toward the metal plates 122 and 123, The ceramic substrate 111 and the metal plates 122 and 123 are bonded to each other. Thus, the substrate 110 for the power module is produced.

(Si layer forming step (S105) / heat sink laminating step (S106))

Next, Si and Ge are fixed to the other surface side of the metal layer 113 of the power module substrate 110 to form the Si layer 126. Next, The amount of Si in the Si layer 126 is set to 0.002 mg / cm 2 or more and 1.2 mg / cm 2 or less, and the amount of Ge is set to 0.002 mg / cm 2 or more and 2.5 mg / cm 2 or less.

Then, the heat sink 140 is laminated on the other surface side of the metal layer 113 with the Si layer 126 interposed therebetween.

(Heat sink heating step (S107))

Next, the substrate 110 for a power module and the heat sink 140 are charged in a vacuum heating furnace under pressure (pressure: 1 to 35 kgf / cm2) in a stacking direction and heated to form a metal layer 113 and a heat sink 140). ≪ / RTI >

Here, in the present embodiment, the pressure in the vacuum furnace is set in the range of 10 -6 Pa or more and 10 -3 Pa or less, and the heating temperature is set in the range of 600 ° C or more and 650 ° C or less.

(Molten metal solidification step (S108))

Next, the temperature is kept constant while the molten metal region is formed. Then, Si and Ge in the molten metal region are further diffused toward the metal layer 113 side and the heat sink 140 side. As a result, the Si concentration and the Ge concentration at the portion which was the molten metal region are gradually lowered, the melting point is increased, and the solidification progresses while the temperature is kept constant. After solidification proceeds in this way, cooling is carried out to room temperature.

In this manner, the power module substrate 110 and the heat sink 140 are bonded to each other to produce a substrate for a power module with a heat sink of the present embodiment.

In the power module with a heat sink and the power module 101 according to the present embodiment having the above-described configuration, Ge is fixed with Si between the heat sink 140 and the metal layer 113, It is not necessary to use a brazing filler metal since the molten metal region is formed by diffusing Ge and further the Si and Ge in the molten metal region are diffused to bond the heat sink 140 and the substrate 110 for power module. Since Si and Ge are directly fixed to the metal layer 113 (metal plate 123), the total thickness of the oxide film existing at the interface between the heat sink 140 and the metal layer 113 (metal plate 123) Thinner than when using a foil. This makes it possible to reliably remove the oxide film and suppress generation of voids at the bonding interface 130 with the metal layer 113 (metal plate 123) and the heat sink 140, (123) and the heat sink 140 can be improved.

In addition, since Ge is added in addition to Si and these Si and Ge are diffused to form a molten metal region, the melting point of the heat sink 140 and the metal layer 113 in the vicinity of the bonding interface 130 is lowered Even if the bonding temperature in the heat sink heating step S107 is set lower than the bonding temperature in the ceramics substrate heating step S103, the heat sink 140 and the power module substrate 110 are bonded .

Since the thickness of the metal layer 113 is larger than the thickness of the circuit layer 112 in the present embodiment, the thickness of the metal layer 113 (that is, the side of the heat sink 140 ) Is set higher than the stiffness on the side of the circuit layer 112, so that the warp of the substrate for a power module with a heat sink after bonding can be suppressed.

Next, a substrate for a power module with a heat sink and a power module according to a third embodiment of the present invention will be described with reference to FIGS. 10 to 14. FIG.

The power module 201 includes a power module substrate 210 on which a circuit layer 212 is formed, a semiconductor chip 3 bonded to the surface of the circuit layer 212 via a solder layer 2, And a heat sink 240 are provided.

The substrate 210 for a power module includes a ceramic substrate 211, a circuit layer 212 formed on one surface (upper surface in Fig. 10) of the ceramics substrate 211, And a metal layer 213 formed on the surface of the substrate (lower surface in Fig. 10).

Further, the ceramics substrate 211 is made of AlN (aluminum nitride) having a high insulating property.

The circuit layer 212 is formed by bonding a metal plate 222 made of a rolled plate of aluminum (so-called 4N aluminum) having a purity of 99.99% or more to the ceramics substrate 211.

The metal layer 213 is formed by bonding a metal plate 223 made of a rolled plate of aluminum (so-called 4N aluminum) having a purity of 99.99% or more to the ceramics substrate 211 in the same manner as the circuit layer 212.

The heat sink 240 is for cooling the above-described substrate 210 for a power module. The heat sink 240 according to this embodiment includes a top plate portion 241 joined to the power module substrate 210, a bottom plate portion 245 arranged to face the top plate portion 241, a top plate portion 241 And a corrugated fin 246 interposed between the bottom plate portion 245 and the bottom plate portion 245. The top plate portion 241 and the bottom plate portion 245 and the corrugated fin 246 form a flow passage (242).

Here, the heat sink 240 is formed by soldering the top plate portion 241, the corrugated fin 246, the corrugated fin 246, and the bottom plate portion 245, respectively. 14, the top plate portion 241 and the bottom plate portion 245 are formed by stacking base layers 241A and 245A made of the A3003 alloy and bonding layers 241B and 245B made of the A4045 alloy And a top plate portion 241 and a bottom plate portion 245 are formed so that the bonding layers 241B and 245B face the corrugated fin 246 side. In other words, the base layer 241A of the top plate portion 241 is in contact with the metal layer 213.

11, at the bonding interface 230 between the heat sink 240 (the base layer 241A of the top plate portion 241) and the metal layer 213 (the metal plate 223), the metal layer 213 (Si), Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li in addition to Si (a metal layer 223) and a heat sink 240 (a base layer 241A of the top plate portion 241) Species or two or more kinds of additional elements are dissolved. In this embodiment, Ag is used as an additive element.

In addition, in addition to Si, the bonding interface between the circuit layer 212 (metal plate 222) and the ceramics substrate 211 and the bonding interface between the metal layer 213 (metal plate 223) and the ceramics substrate 211 Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li. In this embodiment, Ag is used as an additive element.

Here, near the bonding interface 230 of the metal layer 213 and the heat sink 240, the concentration gradient layers 233 and 233, which gradually decrease in Si concentration and Ag concentration as they are separated from the bonding interface 230 in the stacking direction, 234 are formed. Here, Si and additional elements (Ag in the present embodiment) on the bonding interface 230 side of the concentration gradient layers 233 and 234 (near the bonding interface 230 of the metal layer 213 and the heat sink 240) Is set within a range of 0.05 mass% or more and 6.5 mass% or less.

The Si concentration and the Ag concentration in the vicinity of the bonding interface 230 of the metal layer 213 and the heat sink 240 were measured by EPMA analysis (spot diameter 30 占 퐉) at five points at a position of 50 占 퐉 from the bonding interface 230 This is the average value measured. The graph of Fig. 11 shows a line analysis in the lamination direction at the center of the width of the metal layer 213 (the metal plate 223) and the heat sink 240 (the top plate portion 241) And the concentration at the site.

Hereinafter, a method for manufacturing a substrate for a power module with a heat sink having the above-described structure will be described.

(Si bonding step (S201))

First, as shown in Fig. 13, a first Si layer 224 is formed by adhering Si to one surface of a metal plate 222 serving as a circuit layer 212 by sputtering, and a metal layer 213 Si is fixed to one surface of the metal plate 223 by sputtering to form a second Si layer 225. [ One or more additional elements selected from Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li in addition to Si are added to the first Si layer 224 and the second Si layer 225 And in this embodiment, Ag is used as an additive element.

Here, in the present embodiment, the amount of Si in the first Si layer 224 and the second Si layer 225 is set to 0.08 mg / cm 2 or more and 2.7 mg / cm 2 or less. The amount of Ag is set to 0.08 mg / cm2 or more and 5.4 mg / cm2 or less.

(Ceramic substrate laminating step (S202))

Next, as shown in Fig. 13, the metal plate 222 is laminated on one surface side of the ceramics substrate 211, and the metal plate 223 is laminated on the other surface side of the ceramics substrate 211. Next, as shown in Fig. 13, the first Si layer 224 of the metal plate 222 and the second Si layer 225 of the metal plate 223 are formed on the ceramic substrate 211 so as to face the ceramics substrate 211. In this case, , 223 are stacked. That is, the first Si layer 224 and the second Si layer 225 are interposed between the metal plates 222 and 223 and the ceramics substrate 211, respectively.

(Ceramic substrate heating step (S203))

Next, the metal plate 222, the ceramics substrate 211 and the metal plate 223 are charged into the vacuum heating furnace while being pressed (pressure is 1 to 35 kgf / cm2) in the stacking direction and heated, ) And the ceramics substrate 211, the first molten metal region and the second molten metal region are formed.

Here, in the present embodiment, the pressure in the vacuum furnace is set in the range of 10 -6 Pa or more and 10 -3 Pa or less, and the heating temperature is set in the range of 600 ° C or more and 650 ° C or less.

(The first molten metal and the second molten metal solidification step (S204)).

Next, the temperature is kept constant in a state where the first molten metal region and the second molten metal region are formed. Then, Si and Ag in the first molten metal region and the second molten metal region spread further toward the metal plates 222 and 223. As a result, the Si concentration and the Ag concentration at the portions which were the first molten metal region and the second molten metal region are gradually lowered, the melting point is increased, and the solidification progresses while maintaining the temperature constant. As a result, the ceramics substrate 211 and the metal plates 222 and 223 are joined together to form the power module substrate 210.

(Si layer forming step (S205))

Next, Si and Ag are fixed to the other surface of the metal layer 213 by sputtering to form the Si layer 226. [ Here, in this embodiment, the amount of Si in the Si layer 226 is set to 0.08 mg / cm 2 or more and 2.7 mg / cm 2 or less, and the amount of Ag is set to 0.08 mg / cm 2 or more and 5.4 mg / cm 2 or less.

(Heat sink laminating step (S206))

14, a top plate portion 241 constituting a heat sink 240, a corrugated fin 246, and a bottom plate 242 are formed on the other surface side of the metal layer 213 of the power module substrate 210, The plate portion 245 is laminated. At this time, the top plate portion 241 and the bottom plate portion 245 are formed so that the bonding layer 241B of the top plate portion 241 and the bonding layer 245B of the bottom plate portion 245 face the corrugated fin 246 side. Laminated. A flux (not shown) containing, for example, KAlF 4 as a main component is interposed between the top plate portion 241 and the corrugated fin 246, and between the bottom plate portion 245 and the corrugated fin 246 .

The surface of the metal plate 223 on which the Si layer 226 is formed faces the top plate portion 241 of the heat sink 240 and the Si layer 226 is disposed between the metal plate 223 and the heat sink 240 ).

(Heat sink heating step (S207))

Next, the stacked power module substrate 210, the top plate portion 241, the corrugated fin 246, and the bottom plate portion 245 are pressed (pressure 1 to 35 kgf / cm2) in the lamination direction, The molten metal region is formed between the metal plate 223 and the top plate portion 241 of the heat sink 240 by heating. A molten metal layer obtained by melting the bonding layers 241B and 245B is formed between the top plate portion 241 and the corrugated fin 246 and between the bottom plate portion 245 and the corrugated fin 246. [

Here, in the present embodiment, the atmosphere in the atmosphere heating furnace is a nitrogen gas atmosphere, and the heating temperature is set within the range of 550 占 폚 to 630 占 폚.

(Molten metal solidification step (S208))

Next, the temperature is kept constant while the molten metal region is formed. Then, Si and Ag in the molten metal region spread further on the metal plate 223 side and the top plate portion 241 side of the heat sink 240. As a result, the Si concentration and the Ag concentration at the portion which was the molten metal region are gradually lowered, the melting point is increased, and the solidification progresses while maintaining the temperature constant. In other words, the top plate portion 241 of the heat sink 240 and the metal plate 223 are bonded by so-called diffusion liquid phase diffusion bonding. After solidification proceeds in this way, cooling is carried out to room temperature.

The melted metal layer formed between the top plate portion 241 and the corrugated fin 246 and between the bottom plate portion 245 and the corrugated fin 246 is solidified so that the top plate portion 241 and the corrugated fin 246, The plate portion 245 and the corrugated fin 246 are soldered. At this time, an oxide film is formed on the surfaces of the top plate portion 241, the corrugated fin 246, and the bottom plate portion 245, and these oxide films are removed by the above-described flux.

The top plate portion 241, the corrugated fin 246 and the bottom plate portion 245 are soldered to form the heat sink 240 and the heat sink 240 and the power module substrate 210 And a substrate for a power module with a heat sink, which is the present embodiment, is bonded.

In the method for manufacturing a substrate for a power module with a heat sink and a substrate for a power module with a heat sink according to the present embodiment having the above-described structure, Ag is fixed with Si between the heat sink 240 and the metal layer 213 And the heat sink 240 is bonded to the power module substrate 210 by diffusing Si and Ag in the molten metal region to form a molten metal region by diffusing these Si and Ag, The heat sink 240 and the power module substrate 210 can be securely joined.

Here, in the case where the heat sink 240 is formed by soldering using flux, the heat sink 240 is bonded under a nitrogen gas atmosphere at a temperature of 550 ° C or more and 630 ° C or less. In this embodiment, Since Si and the additive element Ag are used for bonding the substrate 210, bonding at a low temperature condition and bonding in a nitrogen gas atmosphere can be performed as described above. Therefore, the heat sink 240 and the power The top plate portion 241 and the corrugated fin 246 and the bottom plate portion 245 are joined together by soldering to form the heat sink 240 at the same time as the module substrate 210 is bonded. Therefore, the manufacturing process of the substrate for the power module with the heat sink can be omitted, and the production cost can be reduced.

Next, a substrate for a power module with a heat sink and a power module according to a fourth embodiment of the present invention will be described with reference to Figs. 15 to 18. Fig.

 The power module 301 includes a power module substrate 310 on which a circuit layer 312 is disposed, a semiconductor chip 3 bonded to the surface of the circuit layer 312 via a solder layer 2, And a heat sink 340 are provided.

The substrate 310 for a power module includes a ceramic substrate 311, a circuit layer 312 formed on one surface (upper surface in Fig. 15) of the ceramic substrate 311, And a metal layer 313 formed on the surface (lower surface in Fig. 15).

Further, the ceramics substrate 311 is made of AlN (aluminum nitride) having high insulation property.

The circuit layer 312 is formed by bonding a metal plate 322 made of a rolled plate of aluminum (so-called 4N aluminum) having a purity of 99.99% or more to the ceramics substrate 311.

The metal layer 313 is formed by bonding a metal plate 323 composed of a rolled plate of aluminum (so-called 4N aluminum) having a purity of 99.99% or more to the ceramics substrate 311, like the circuit layer 312.

The heat sink 340 is for cooling the above-described substrate 310 for a power module. The heat sink 340 according to this embodiment includes a top plate portion 341 joined to the power module substrate 310, a bottom plate portion 345 arranged to face the top plate portion 341, a top plate portion 341, And a corrugated fin 346 interposed between the bottom plate portion 345 and the bottom plate portion 345. The flow pathway 342 is formed by a channel plate 341, a bottom plate portion 345, 342 are partitioned.

Here, the heat sink 340 is formed by soldering a top plate portion 341, a corrugated fin 346, a corrugated fin 346, and a bottom plate portion 345, respectively.

The metal layer 313 (the metal plate 323) and the top plate portion 341 are bonded to the top surface 341 of the heat sink 340 and the metal layer 313 Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li. In this embodiment, Ag is used as an additive element.

In addition, in addition to Si, the bonding interface between the circuit layer 312 (metal plate 322) and the ceramic substrate 311 and the bonding interface between the metal layer 313 (metal plate 323) and the ceramic substrate 311 One or more additional elements selected from Cu, Zn, Ge, Ag, Mg, Ca, Ga and Li are dissolved. In this embodiment, Ag is dissolved.

Hereinafter, a method for manufacturing a substrate for a power module with a heat sink having the above-described structure will be described.

(Fixing layer formation step (S301))

17, a first Si layer 324 is formed by fixing Si on one surface of a metal plate 322 to be a circuit layer 312 by sputtering, and at the same time, a metal layer 313 Si is fixed to one surface of the metal plate 323 by sputtering to form the second Si layer 325. [ The Si layer 326 is also formed by fixing Si on the other surface of the metal plate 323 by sputtering.

In addition to Si, at least one selected from Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li is added to the first Si layer 324, the second Si layer 325, Two or more kinds of additional elements are fixed, and in the present embodiment, Ag is used as an additive element.

Here, in this embodiment, the amount of Si in the first Si layer 324, the second Si layer 325, and the Si layer 326 is set to 0.08 mg / cm 2 or more and 2.7 mg / cm 2 or less. The amount of Ag is set to 0.08 mg / cm2 or more and 5.4 mg / cm2 or less.

(Laminating step (S302))

17, a metal plate 322 is laminated on one surface side of the ceramic substrate 311 and a metal plate 323 is laminated on the other surface side of the ceramic substrate 311. Next, as shown in Fig. 17, the first Si layer 324 of the metal plate 322 and the second Si layer 325 of the metal plate 323 are formed face the ceramic substrate 311 so as to face the ceramic substrate 311. In this case, , And 323 are stacked.

Further, a top plate portion 341 is stacked on the surface side of the metal plate 323 where the Si layer 326 is formed.

(Heating step (S303))

Next, the metal plate 322, the ceramics substrate 311, the metal plate 323, and the top plate portion 341 are charged in the vacuum heating furnace under pressure in the stacking direction (pressure is 1 to 35 kgf / cm2) A first molten metal region and a second molten metal region are formed at the interface between the metal plates 322 and 323 and the ceramics substrate 311 and a molten metal region is formed between the metal plate 323 and the top plate portion 341 .

Here, in the present embodiment, the pressure in the vacuum furnace is set in the range of 10 -6 Pa or more and 10 -3 Pa or less, and the heating temperature is set in the range of 600 ° C or more and 650 ° C or less.

(Molten metal solidification step (S304))

Next, the temperature is kept constant in a state where the first molten metal region and the second molten metal region are formed. Then, Si and Ag in the first molten metal region and the second molten metal region are further diffused toward the metal plates 322 and 323. Then, the Si concentration and the Ag concentration at the portions which were the first molten metal region and the second molten metal region are gradually lowered, the melting point is raised, and the solidification progresses while maintaining the temperature constant. Thus, the ceramics substrate 311 and the metal plates 322 and 323 are bonded.

Further, the temperature is kept constant in a state where the molten metal region is formed. Then, Si and Ag in the molten metal region spread to the metal plate 323 and the top plate portion 341 side. Then, the Si concentration and the Ag concentration at the portion which was the molten metal region are gradually lowered, the melting point is raised, and the solidification progresses while the temperature is kept constant. Thereby, the metal plate 323 and the top plate portion 341 are joined.

(Pin stacking step (S305))

18, a brazing filler metal foil 347 (e.g., a low-melting-point aluminum alloy foil such as an Al-10% Si alloy foil) or a corrugated fin (for example, 346 and the bottom plate portion 345 are stacked. At this time, the bottom plate portion 345 is laminated so that the bonding layer 345B of the bottom plate portion 345 faces the corrugated fin 346 side. Between the top plate portion 341 and the corrugated fin 346 and between the bottom plate portion 345 and the corrugated fin 346, a flux (not shown) containing KAlF 4 as a main component, for example, is interposed .

(Soldering step (S306))

Next, the top plate portion 341, the corrugated fin 346 and the bottom plate portion 345 are charged into the atmosphere heating furnace under the pressure (pressure 1 to 35 kgf / cm2) in the stacking direction and heated, A molten metal layer obtained by melting the brazing filler metal 347 and the bonding layer 345B is formed between the corrugated fin 341 and the corrugated fin 346 and between the bottom plate 345 and the corrugated fin 346. [

Here, in this embodiment, the atmosphere in the atmosphere heating furnace is a nitrogen gas atmosphere, and the heating temperature is set within the range of 550 占 폚 to 630 占 폚.

The molten metal layer formed between the top plate portion 341 and the corrugated fin 346 and between the bottom plate portion 345 and the corrugated fin 346 is solidified by cooling so that the top plate portion 341 and the corrugated fin 346 The bottom plate portion 345 and the corrugated fin 346 are soldered. At this time, an oxide film is formed on the surfaces of the top plate portion 341, the corrugated fin 346, and the bottom plate portion 345, and these oxide films are removed by the above-described flux.

In this manner, a substrate for a power module with a heat sink, which is the present embodiment, is manufactured.

In the method for manufacturing a substrate for a power module with a heat sink and a substrate for a power module with a heat sink according to the present embodiment having the above-described structure, a heat- Ag is fixed together with Si, and the Si and Ag are diffused to form a molten metal region. Further, Si and Ag in the molten metal region are diffused to form a top plate portion 341 of the heat sink 340 and a substrate The top plate 341 of the heat sink 340 and the substrate 310 for the power module can be securely bonded even under relatively low temperature conditions.

Although the embodiment of the present invention has been described above, the present invention is not limited thereto, and can be appropriately changed without departing from the technical idea of the invention.

For example, the description has been made on the assumption that the metal plate constituting the circuit layer and the metal layer is a rolled plate of pure aluminum having a purity of 99.99%. However, the present invention is not limited to this, and aluminum (2N aluminum) having a purity of 99% may be used.

In the above description, the ceramic substrate is made of AlN. However, the present invention is not limited to this, and it may be made of other ceramics such as Si 3 N 4 and Al 2 O 3 .

In the second, third, and fourth embodiments, Ge or Ag is fixed as an additional element together with Si in the Si layer forming step. However, the present invention is not limited to this. One or more elements selected from Cu, Zn, Ge, Ag, Mg, Ca, Ga and Li may be used as the additional element. Here, it is preferable that the sum of the bonding amount of Si and the added element is 0.002 mg / cm2 or more and 10 mg / cm2 or less.

In addition, in the Si layer forming step, Si is fixed to the other surface of the metal plate as the metal layer. However, the present invention is not limited to this, and Si may be adhered to the bonding surface of the heat sink, Si may be fixed to the other surface of the surface and the metal plate.

In the above description, Si is fixed by sputtering in the Si layer forming step. However, the present invention is not limited to this, and plating, vapor deposition, CVD, cold spray or application of paste or ink in which powder is dispersed The Si may be fixed.

In addition, in the Si layer forming step, Al may be fixed together with Si.

In the present embodiment, one power module substrate is bonded on the heat sink. However, the present invention is not limited to this, and a plurality of power module substrates may be bonded on one heat sink.

Further, etc. The first and second embodiment in form, has been described by the bonding of a heat sink and a metal layer (metal plate), carried out using a vacuum heating, it is not limited to, N 2 atmosphere, Ar atmosphere and a He atmosphere The heat sink may be bonded to the metal layer (metal plate).

Further, the ceramic substrate and the metal plate are bonded without using a brazing material. However, the present invention is not limited thereto, and a substrate for a power module in which a ceramics substrate and a metal plate are joined by using a brazing material may be used.

In the third embodiment, the top plate portion and the bottom plate portion are made of a laminated aluminum material having a base layer and a bonding layer. However, the present invention is not limited to this, and a corrugated fin may be used, for example, And a clad material having a bonding layer made of A4045 on both sides of the core material. In this case, a simple aluminum plate can be used for the top plate portion and the bottom plate portion.

The material of the top plate portion, the corrugated fin, and the bottom plate portion is not limited to the present embodiment.

Further, the structure of the heat sink including the shape of the corrugated fin and the like is not limited to this embodiment. For example, only the top plate portions in the third and fourth embodiments may be bonded to the power module substrate with a heat sink.

19, the second metal plate 413 may have a structure in which a plurality of metal plates 413A and 413B are laminated. In this case, the metal plate 413A located on one side (upper side in Fig. 19) of the second metal plate 413 is bonded to the ceramics substrate 411, and the metal plate 413A located on the other side 413B are bonded to the top plate portion 441 of the heat sink 440. By forming the Si layer between the metal plate 413B on the other side and the top plate portion 441 of the heat sink 440, the metal plate 413B located on the other side and the top plate portion 441 are joined. Here, the second metal plate 413 may be constituted by joining the laminated metal plates 413A and 413B via the Si layer. Although two metal plates 413A and 413B are laminated in Fig. 19, there is no limitation on the number of laminated plates. As shown in Fig. 19, the metal plates to be laminated may have different sizes and shapes, or may be adjusted to the same size and shape. The composition of these metal plates may be different.

3 Semiconductor chip (electronic parts)
10, 110, 210, 310, 410 substrate for power module
11, 111, 211, 311, 411 Ceramics substrate
12, 112, 212, 312, and 412 circuit layers (first metal plate)
13, 113, 213, 313, 413 metal layer (second metal plate)
40, 140, 240, 340, 440 Heatsink
24, 124, 224, 324 A first Si layer (first metal layer)
25, 125, 225, 325 Second Si layer (second metal layer)
26, 126, 226, 326 Si layers
27 first molten metal region
28 second molten metal region
29 Molten metal area
30, 130, 230 bonded interface

Claims (13)

A first metal plate made of aluminum having one surface bonded to the surface of the ceramic substrate; a second metal plate made of aluminum having one surface bonded to the back surface of the ceramic substrate; and a second metal plate bonded to the ceramic substrate And a heat sink made of aluminum or an aluminum alloy joined to the other surface opposite to the one surface, the method comprising the steps of:
A ceramic substrate joining step of joining the ceramics substrate and the first metal plate and the ceramics substrate and the second metal plate;
And a heat sink joining step of joining the heat sink to the other surface of the second metal plate,
In the heat sink joining step,
A Si layer forming step of forming a Si layer by fixing Si to at least one of the other surface of the second metal plate and the bonding surface of the heat sink;
A heat sink laminating step of laminating the second metal plate and the heat sink through the Si layer;
A heat sink heating step of pressing and heating the stacked second metal plate and the heat sink in a stacking direction to form a molten metal region at an interface between the second metal plate and the heat sink,
And a molten metal solidification step of solidifying the molten metal region to join the second metal plate and the heat sink,
Wherein the molten metal region is formed at an interface between the second metal plate and the heat sink by diffusing Si of the Si layer into the second metal plate and the heat sink in the heat sink heating step A method for manufacturing a substrate for an attached power module. The method according to claim 1,
Wherein at least one of Cu, Zn, Ge, Ag, Mg, Ca, Ga, and Li is added to at least one of the other surface of the second metal plate and the bonding surface of the heat sink, A method for manufacturing a substrate for a power module with a heat sink, characterized in that two or more kinds of additional elements are fixed. 3. The method according to claim 1 or 2,
Wherein the step of forming the Si layer comprises fixing Al together with Si. 3. The method according to claim 1 or 2,
In the ceramics substrate bonding step,
At least one of Cu or Si is adhered to at least one of a bonding surface of the ceramics substrate and a bonding surface of the first metal plate at a bonding interface between the ceramics substrate and the first metal plate to form a first metal layer A metal forming a second metal layer by fixing at least one of Cu or Si to at least one of a bonding surface of the ceramics substrate and a bonding surface of the second metal plate at a bonding interface between the ceramics substrate and the second metal plate, A fixing step,
A ceramic substrate lamination step of laminating the ceramics substrate and the first metal plate via the first metal layer and laminating the ceramics substrate and the second metal plate with the second metal layer interposed therebetween;
The first metal plate, the ceramic substrate, and the second metal plate are pressed and heated in the lamination direction to form an interface between the first metal plate and the ceramics substrate and the interface between the ceramics substrate and the second metal plate, 1) a ceramic substrate heating step of forming a molten metal region and a second molten metal region;
And a first molten metal and a second molten metal solidification step for solidifying the first molten metal region and the second molten metal region to join the first metal plate and the ceramics substrate and the ceramics substrate to the second metal plate,
At least one of Cu and Si of the first metal layer and the second metal layer is diffused into the first metal plate and the second metal plate in the step of heating the ceramics substrate to form an interface between the first metal plate and the ceramic substrate, Wherein the first molten metal region and the second molten metal region are formed at the interface between the ceramics substrate and the second metal plate. 3. The method according to claim 1 or 2,
Wherein the ceramic substrate bonding step and the heat sink bonding step are performed at the same time. 3. The method according to claim 1 or 2,
The Si layer forming step may be performed by at least one of bonding surfaces of the heat sink and the other surface of the second metal plate by plating, vapor deposition, CVD, sputtering, cold spray, or application of paste or ink in which the powder is dispersed Wherein the Si substrate is bonded to the Si substrate. 3. The method according to claim 1 or 2,
Wherein the second metal plate is formed by stacking a plurality of metal plates. delete delete delete delete delete delete
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040022029A1 (en) * 2000-08-09 2004-02-05 Yoshiyuki Nagatomo Power module and power module with heat sink
JP2010093225A (en) * 2008-03-17 2010-04-22 Mitsubishi Materials Corp Substrate for power module with heat sink and method for manufacturing the same, power module with heat sink, and substrate for power module
JP2010098057A (en) * 2008-10-15 2010-04-30 Mitsubishi Materials Corp Substrate for power module with heat sink, power module with heat sink and substrate for power module with buffer layer

Family Cites Families (2)

* Cited by examiner, † Cited by third party
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JP2001018074A (en) * 1999-07-07 2001-01-23 Sumitomo Metal Ind Ltd Manufacture of aluminum clad material
JP4747315B2 (en) * 2007-11-19 2011-08-17 三菱マテリアル株式会社 Power module substrate and power module

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040022029A1 (en) * 2000-08-09 2004-02-05 Yoshiyuki Nagatomo Power module and power module with heat sink
JP2010093225A (en) * 2008-03-17 2010-04-22 Mitsubishi Materials Corp Substrate for power module with heat sink and method for manufacturing the same, power module with heat sink, and substrate for power module
JP2010098057A (en) * 2008-10-15 2010-04-30 Mitsubishi Materials Corp Substrate for power module with heat sink, power module with heat sink and substrate for power module with buffer layer

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