JP5935517B2 - Brazing material, joining method using brazing material, and semiconductor module - Google Patents

Description

  The present invention relates to a brazing material, a joining method using a brazing material, and a semiconductor module having a joining portion using a brazing material.

  A cross-sectional view of a semiconductor module 11 according to the prior art is shown in FIG. In the semiconductor module 11 shown in FIG. 3, the semiconductor element 2 is, for example, an IGBT (Insulated Gate Bipolar Transistor) or the like, and is provided in the wiring layer 3 formed on the insulating substrate 5. A heat dissipation substrate 14 is provided on the surface of the insulating substrate 5 opposite to the surface on which the wiring layer 3 is formed via the heat transfer layer 13.

  The wiring layer 3 and the heat transfer layer 13 are formed using, for example, aluminum or copper. Moreover, the water cooling jacket 7 is provided in the surface on the opposite side to the surface in which the heat-transfer layer 13 of the thermal radiation board | substrate 14 is provided through an O-ring (not shown). In the water cooling jacket 7, a coolant channel 7a through which the coolant flows is formed. Then, the heat dissipation board 14 and the water cooling jacket 7 are fixed with bolts 8. In some cases, the heat dissipation substrate 14 and the water cooling jacket 7 are joined by brazing without using the bolts 8.

  In such a power semiconductor module 11, the heat generated from the semiconductor element 2 is transmitted to the water cooling jacket 7 through the heat dissipation substrate 14 and is radiated from the water cooling jacket 7 (for example, Patent Documents 1 and 2).

  The insulating substrate 5 is, for example, an aluminum nitride substrate, an aluminum oxide substrate, or a silicon nitride substrate. Further, for example, aluminum having excellent thermal conductivity is used for the heat dissipation substrate 14 and the water cooling jacket 7. A method such as brazing is used as a bonding method for each member such as bonding of the insulating substrate 5 and the heat transfer layer 13 or bonding of the heat transfer layer 13 and the heat dissipation substrate 14 (for example, Patent Documents 3 and 4; Patent Document 1).

  The ceramic constituting the insulating substrate 5 has a smaller linear expansion coefficient than the aluminum constituting the wiring layer 3 and the heat transfer layer 13. Therefore, when the semiconductor element 2 generates heat, a crack occurs in the insulating substrate 5 due to a difference in thermal expansion between the insulating substrate 5 and the heat transfer layer 13 (or the heat dissipation substrate 14), or between the insulating substrate 5 and the heat transfer layer 13. There was a possibility that peeling would occur on the joint surface.

  In order to improve this problem, a semiconductor module 12 is known in which a stress relaxation layer 15 is interposed between an insulating substrate 5 and a heat dissipation substrate 14 as shown in FIG. For example, an AlSiC composite material is used as the stress relaxation layer 15. However, when the AlSiC composite material is used, even though the generation of cracks in the insulating substrate 5 and the occurrence of separation between the insulating substrate 5 and the heat transfer layer 13 can be suppressed, the stress relaxation layer 15 is interposed, so that the semiconductor element 2 There was a possibility that the heat dissipation was reduced.

  Therefore, a semiconductor module using a composite member in which a carbon material is impregnated with aluminum or an aluminum alloy is proposed as a stress relaxation layer (for example, Patent Documents 5 and 6).

JP 2007-141932 A JP 2003-86744 A JP-A-4-294890 Japanese Patent Laid-Open No. 11-130555 JP 2010-98059 A JP 2011-35308 A

Kazuyuki Miyagawa, 2 others, “Study on brazing technology for difficult-to-join materials”, [online], 2002, Yamanashi Prefectural Industrial Technology Center, Research Report, No. 16, [Search May 30, 2012], Internet, <URL: http://www.pref.yamanashi.jp/yitc/Houkoku/data/H13/01.pdf>

  However, since the composite member is mainly composed of carbon having poor brazing properties, the bonding strength between the composite member and the insulating substrate may be weakened, and it is required to perform bonding with higher reliability. In the prior art, when a composite member is provided on a semiconductor module, a metal skin layer or the like is formed on the surface of the composite member to ensure the reliability of the joint between the composite member and another member.

  In view of the above circumstances, the present invention provides a technique that contributes to improving the reliability of a joint portion between a composite member and another member in a semiconductor module having a composite member in which a carbon material is impregnated with aluminum or an aluminum alloy. The purpose is that.

  One aspect of the brazing material of the present invention that achieves the above object is that 0.1 to 2.0% by weight of Ti, 22 to 32% by weight of Cu, 3.4 to 7.4% by weight of Si, and the balance It is characterized by containing a mixture of Al and inevitable impurities.

  Another embodiment of the brazing material of the present invention that achieves the above object is characterized in that the brazing material is obtained by mixing a solvent with a mixture of Al powder, Cu powder, Si powder, and Ti powder.

  Another aspect of the brazing material of the present invention that achieves the above object is characterized in that the brazing material joins a composite member in which a carbon material is impregnated with aluminum or an aluminum alloy and an insulating substrate.

  Moreover, one mode of the joining method using the brazing filler metal of the present invention that achieves the above object is that a composite member obtained by impregnating a carbon material with aluminum or an aluminum alloy contains 0.1 to 2.0 wt% of Ti and Cu. An insulating substrate is provided via a brazing material containing 22 to 32% by weight, Si of 3.4 to 7.4% by weight, and the balance being a mixture of Al and inevitable impurities, and the composite member and the insulating substrate And the brazing material is heated and brazed in an inert gas atmosphere or a vacuum atmosphere.

  According to another aspect of the semiconductor module of the present invention for achieving the above object, a semiconductor element, a wiring layer provided with the semiconductor element, and a first composite in which the wiring layer is impregnated with a carbon material with aluminum or an aluminum alloy. An insulating substrate provided via a member, and a radiator provided via a second composite member obtained by impregnating a carbon material with aluminum or an aluminum alloy on a surface opposite to the surface on which the wiring layer of the insulating substrate is provided And at least one of the joint portion between the first composite member and the insulating substrate or the joint portion between the second composite member and the insulating substrate is 0.1 to 2.0% by weight. It is characterized by joining with a brazing material containing Ti, 22 to 32% by weight of Cu, 3.4 to 7.4% by weight of Si, and the balance of Al and inevitable impurities.

  Another aspect of the semiconductor module of the present invention that achieves the above object is characterized in that a nickel layer is formed on the brazed surface of the first composite member or the second composite member.

  According to the above invention, in a semiconductor module having a composite member in which a carbon material is impregnated with aluminum or an aluminum alloy, it is possible to contribute to improving the reliability of the joint portion between the composite member and another member.

It is principal part sectional drawing of the semiconductor module which concerns on embodiment of this invention. It is explanatory drawing explaining the joining method of the semiconductor module which concerns on Example 1 of this invention. It is sectional drawing of the semiconductor module which concerns on a prior art. It is sectional drawing of the semiconductor module which has a composite member of a prior art.

  A brazing material, a joining method using a brazing material, and a semiconductor module having a joining portion using a brazing material will be described in detail with reference to the drawings. In the following description, FIGS. 1 and 2 schematically show a semiconductor module according to an embodiment of the present invention, and the dimensional ratio on the drawing does not necessarily match the actual dimensional ratio. .

  FIG. 1 is a cross-sectional view of a main part of a semiconductor module 1 according to an embodiment of the present invention. As shown in FIG. 1, the semiconductor module 1 according to the embodiment includes a semiconductor element 2, a wiring layer 3, a heat transfer layer 4, an insulating substrate 5, a heat dissipation substrate 6, and a water cooling jacket 7.

  The semiconductor element 2 is a switching element such as an IGBT or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), for example, and is provided on the wiring layer 3 by soldering. The semiconductor element 2 may be one in which a plurality of elements such as a circuit including a switching element and a rectifying element such as a free wheeling diode (FWD) form an electric circuit instead of the switching element alone.

  The wiring layer 3 is provided on the insulating substrate 5 via the heat transfer layer 4. The wiring layer 3 is formed using, for example, aluminum or copper.

  The heat transfer layer 4 is a member having high thermal conductivity and a linear thermal expansion coefficient close to the linear thermal expansion coefficient of the insulating substrate 5. For example, the carbon material (porous carbon material, carbon fiber, etc.) is made of aluminum or aluminum. A carbon / aluminum composite member impregnated with an alloy (hereinafter referred to as a composite member) is used. A specific example of the composite member is ALC400 (manufactured by AM Technology), which is a composite member obtained by impregnating a porous carbon material with aluminum. The linear expansion coefficient of ALC400 is 7 ppm / K, which is smaller than the linear expansion coefficient of aluminum (17 ppm / K), and is an alumina substrate (linear expansion coefficient: 8 ppm / K) used as the insulating substrate 5, aluminum nitride It is close to a substrate (linear expansion coefficient: 4.6 ppm / K) and a silicon nitride substrate (linear expansion coefficient: 3.5 ppm / K). In addition, the thermal conductivity of ALC400 is 440 W / mK, which is higher than that of copper (390 W / mk) and aluminum (220 W / mK). The thickness of the heat transfer layer 4 is preferably 0.5 to 6.0 mm. Even when the heat transfer layer 4 containing the carbon material and the wiring layer 3 are fixed by mechanical means (such as fastening with bolts) by setting the thickness of the heat transfer layer to 0.5 mm or more, the heat transfer layer 4 mechanical strength can be secured. Moreover, the heat conductivity of the heat transfer layer 4 decreases as the thickness of the heat transfer layer 4 increases. Therefore, the heat conductivity of the heat transfer layer 4 can be improved by setting the thickness of the conductive layer 4 to 6.0 mm or less.

The insulating substrate 5 includes a first main surface on which the wiring layer 3 is provided via the heat transfer layer 4 and a second main surface on which the water cooling jacket 7 is provided on the opposite side of the first main surface via the heat dissipation substrate 6. Have. The material and thickness of the insulating substrate 5 are determined in consideration of required insulating properties, thermal conductivity, and mechanical strength. For example, as the insulating substrate 5, an aluminum nitride (AlN) plate, an aluminum oxide (Al ₂ O ₃ ) plate, a silicon nitride (N ₄ Si ₃ ) plate or the like having a thickness of 0.3 to 2.0 mm is used. .

  The heat dissipation substrate 6 is the same composite member as the heat transfer layer 4 and transfers heat generated in the semiconductor element 2 to the water cooling jacket 7. The thickness of the heat dissipation substrate 6 is preferably 3.0 to 6.0 mm, and this thickness is determined in consideration of the mechanical strength and thermal conductivity of the heat dissipation substrate 6 in the same manner as the thickness of the heat transfer layer 4. .

  The water cooling jacket 7 is provided on the second main surface of the insulating substrate 5 through the heat dissipation substrate 6. The water cooling jacket 7 is made of, for example, aluminum having excellent thermal conductivity, and a coolant channel 7a through which a coolant flows is formed therein. An O-ring (not shown) is provided between the water cooling jacket 7 and the heat dissipation board 6, and the water cooling jacket 7 and the heat dissipation board 6 are fixed with bolts 8. Note that the water cooling jacket 7 and the heat dissipation substrate 6 may be joined by brazing without using the bolts 8, and the brazing material is, for example, a sheet shape made of an Al—Si alloy, an Al—Si—Mg alloy, or the like. Aluminum brazing material is used.

  In the semiconductor module 1 according to the embodiment of the present invention, the bonding between the heat transfer layer 4 and the insulating substrate 5 and the heat radiating substrate 6 and the insulating substrate 5 includes 0.1 to 2.0 wt% of Ti (titanium), and the balance Uses an Al-Cu-Si (aluminum-copper-silicon) based alloy and an Al-Cu-Si-Ti based alloy which is an inevitable impurity. The Al—Cu—Si alloy containing Ti has a eutectic composition of Al-26.6Cu-5.4Si and a melting point of 524 ° C. Therefore, Al—Cu— containing 0.1 to 2.0% by weight of Ti as a brazing material for joining the ceramic substrate (insulating substrate 5) and the composite member (heat transfer layer 4 or heat dissipation substrate 6) at 600 ° C. or less. A highly reliable joint surface is obtained using a Si-based alloy. In addition, when the amount of Cu or Si in the Al—Cu—Si based alloy is greatly different from the amount of Cu or Si that is the eutectic composition of the Al—Cu—Si based alloy, in the temperature range of 550 to 600 ° C. Brazing becomes difficult. Therefore, the Cu content with respect to the Al—Cu—Si alloy is preferably 22 to 32% by weight, and the Si content is preferably 3.4 to 7.4% by weight. In particular, by adjusting the content of Cu and Si with respect to the Al—Cu—Si based alloy to be a eutectic composition ratio (Al-26.6Cu-5.4Si), the melting point change is small and good. A brazing material that can be contacted can be obtained.

  Next, specific examples will be given to describe the brazing material, the joining method using the brazing material, and the semiconductor module 1 having the joining portion using the brazing material in more detail.

[Example 1]
(1) Preparation of brazing material Ti powder so that the brazing material contains 1.6 wt% Ti, a mixture of 26.6 wt% Cu, 5.4 wt% Si, the balance being Al. (Particle size: 38 μm or less), Cu powder (50% particle size: 1 μm), Si powder (50% particle size: 5 μm), Al powder (50% particle size: 3 μm) are mixed to obtain a quaternary mixed powder. (All powders are manufactured by High Purity Chemical Laboratory). Since the Ti powder has a larger particle size than the Al, Cu, and Si powder, it was pulverized in advance in a mortar and then mixed with other powders. The quaternary mixed powder was mixed with a ball mill for 1 h, and then an appropriate amount of ethanol was added so as to form a paste, thereby preparing the brazing material of Example 1.

(2) Creation of Joining Sample Using Brazing Material ALC400 (manufactured by AM Technology) was used as the heat transfer layer 4 and the heat dissipation substrate 6 of the semiconductor module 1 shown in FIG. Further, an AlN substrate was used as the insulating substrate 5. In the description of the embodiment, the bonding between the heat transfer layer 4 and the insulating substrate 5 will be described in detail, but the heat dissipation substrate 6 and the insulating substrate 5 can also be bonded by the same method.

  As shown in FIG. 2, the brazing material 9 of Example 1 was applied to one surface of the heat transfer layer 4, and the heat transfer layer 4 was provided on the insulating substrate 5 via the brazing material 9. Note that the bonding surfaces of the heat transfer layer 4 and the insulating substrate 5 were degreased and washed in a 1 mol / l sodium hydroxide aqueous solution for 30 minutes before brazing. In a state where the heat transfer layer 4 was pressed in the direction of the insulating substrate 5 by the pressing member 10, the heat transfer layer 4 and the insulating substrate 5 were brazed by heating in an argon gas atmosphere. The load pressure is 0.05 MPa, and the insulating substrate 5 provided with the heat transfer layer 4 is subjected to temperatures of 525 ° C.-30 min, 550 ° C.-30 min, 575 ° C.-30 min, 600 ° C.-30 min, and 625 ° C.-30 min. And 5 bonded samples were obtained. Table 1 shows the joining conditions of the joined samples joined using the brazing materials of Examples 1 and 2 and Comparative Examples 1 and 2.

[Example 2]
(1) Preparation of brazing material Ti, so that the brazing material contains 0.8 wt% Ti, 26.6 wt% Cu, 5.4 wt% Si, and the balance Al. Cu, Si and Al powders were mixed to obtain a quaternary mixed powder (all powders were manufactured by High Purity Chemical Laboratory). The same powder as in Example 1 was used for each powder. And similarly to Example 1, Ti powder was pulverized in a mortar in advance and then mixed with other powders. This quaternary mixed powder was mixed with a ball mill for 1 h, and then an appropriate amount of ethanol was added so as to form a paste, thereby preparing a brazing material of Example 2.

(2) Joining Method Using Brazing Material Similar to the joining method of Example 1, the brazing material of Example 2 was applied to one surface of the heat transfer layer, and the heat transfer layer was provided on the insulating substrate via the brazing material. In a state where the heat transfer layer was pressed toward the insulating substrate by the pressing member, brazing was performed by heating to a predetermined bonding temperature in an argon atmosphere to obtain five bonded samples.

[Comparative Example 1]
(1) Preparation of brazing material Cu, Si, Al powder is mixed so that the brazing material is a mixture of 26.6 wt% Cu, 5.4 wt% Si, and the balance is Al, and ternary mixing is performed. Powders were obtained (all powders were manufactured by High Purity Chemical Laboratory). The same powder as in Example 1 was used for each powder. This ternary mixed powder was mixed with a ball mill for 1 h, and then an appropriate amount of ethanol was added so as to form a paste, thereby preparing a brazing material of Comparative Example 1.

(2) Joining Method Using Brazing Material Similar to the joining method of Example 1, the brazing material of Comparative Example 1 was applied to one surface of the heat transfer layer, and the heat transfer layer was provided on the insulating substrate via the brazing material. In a state where the heat transfer layer was pressed toward the insulating substrate by the pressing member, brazing was performed by heating to a predetermined bonding temperature in an argon atmosphere to obtain five bonded samples.

[Comparative Example 2]
(1) Preparation of brazing material Ti, so that the brazing material contains 2.5% by weight of Ti, 26.6% by weight of Cu, 5.4% by weight of Si, the balance being Al. Cu, Si and Al powders were mixed to obtain a quaternary mixed powder (all powders were manufactured by High Purity Chemical Laboratory). The same powder as in Example 1 was used for each powder. And similarly to Example 1, Ti powder was pulverized in a mortar in advance and then mixed with other powders. This quaternary mixed powder was mixed with a ball mill for 1 h, and then an appropriate amount of ethanol was added so as to form a paste, thereby preparing a brazing material of Comparative Example 2.

(2) Joining Method Using Brazing Material Similar to the joining method of Example 1, the brazing material of Example 2 was applied to one surface of the heat transfer layer, and the heat transfer layer was provided on the insulating substrate via the brazing material. In a state where the heat transfer layer was pressed toward the insulating substrate by the pressing member, brazing was performed by heating to a predetermined bonding temperature in an argon atmosphere to obtain five bonded samples.

[Evaluation of brazing material]
(1) Evaluation of visually joined portion The joining sample joined at 550 ° C., 575 ° C., and 600 ° C. is transmitted regardless of the brazing material of Examples 1 and 2 and Comparative Examples 1 and 2. It was confirmed by visual observation that the heat layer and the insulating substrate were well bonded.

  On the other hand, the joining sample joined at 525 ° C. has a state in which the brazing filler metal component does not melt in a part of the joining portion even when any of the brazing fillers of Examples 1 and 2 and Comparative Examples 1 and 2 is used. It was confirmed that it remained.

  In addition, as for the joining sample joined at 625 ° C., even if any of the brazing materials of Examples 1 and 2 and Comparative Examples 1 and 2 is used, a stain of Al that is a component of ALC400 that is a heat transfer layer is used. As a result, it was confirmed that unevenness was formed on the surface of the heat transfer layer due to exudation of Al.

  Then, the heat cycle test was done with respect to the joining sample joined on the temperature conditions (600-525 degreeC) which a change does not arise in a heat-transfer layer, and the evaluation with respect to the junction part between a heat-transfer layer and an insulated substrate was performed.

(2) Heat cycle test Using each brazing material of Examples 1 and 2 and Comparative Examples 1 and 2, a heat cycle test was performed on the joined samples joined at 525 ° C, 550 ° C, 575 ° C, and 600 ° C. . The heat cycle test was a test in which 125 ° C. (holding time 30 min) and −40 ° C. (holding time 30 min) were alternately repeated 1000 cycles. The evaluation of the bonded portion of the bonded sample was visually evaluated as to whether or not peeling occurred at the bonded portion between the heat transfer layer and the insulating substrate after the heat cycle test. Table 2 shows the evaluation results of the joints. In Table 2, the bonding sample in which the heat transfer layer and the insulating substrate were not peeled was marked with ◯, and the bonding sample in which peeling was confirmed on the heat transfer layer and the insulating substrate was marked with x.

  As shown in Table 2, when the brazing material of Examples 1 and 2 was used, any of the bonded samples bonded at 550 ° C. to 600 ° C. peeled off at the bonded portion between the heat transfer layer and the insulating substrate after the heat cycle test. It was not confirmed and the bonding between the heat transfer layer and the insulating substrate was maintained. On the other hand, when the brazing material of Comparative Examples 1 and 2 was used, in any of the bonded samples bonded at 525 ° C. to 600 ° C., peeling was confirmed at the bonded portion between the heat transfer layer and the insulating substrate after the heat cycle test. .

In the brazing materials of Examples 1 and 2, Ti activates the aluminum oxide film on the surface of the composite member and promotes the reaction of the brazing surface by adding a small amount of Ti to the Al—Cu—Si alloy. it is conceivable that. When the mixing amount of Ti is 0.1% by weight or less, the aluminum oxide film on the surface of the composite member cannot be activated, and when Ti is 2.0% by weight or more, the melting point of the quaternary alloy is increased and the intermetallic compound is increased. It is considered that the brazing material becomes hard and brittle when TiAl ₃ is produced. Therefore, by mixing 0.1 wt% or more and 2.0 wt% or less of Ti with respect to the brazing material, it is possible to bond the heat transfer layer and the insulating substrate with high reliability.

  As described above, the brazing material of the present invention is inevitable with 0.1 to 2.0% by weight of Ti, Cu of 22 to 32% by weight, Si of 3.4 to 7.4% by weight, and the balance of Al. And a brazing material and a joining method using this brazing material, the joining of an insulating substrate such as aluminum nitride and a composite member mainly composed of carbon. Reliability can be improved.

  Since Ti has a high melting point, the effect of lowering the melting point of the brazing material cannot be expected. However, since Ti is an active metal and activates the aluminum oxide film on the surface of the composite member, it has good wettability with aluminum, and Ti and carbon are TiC. It is known to form (titanium carbide) and is considered to have good wettability with carbon. Further, when a small amount of Ti is added to an eutectic composition Al-Cu-Si alloy, the composition of the obtained brazing material is slightly deviated from the eutectic composition of the Al-Cu-Si alloy. The melting point of is considered to only shift from the melting point (524 ° C.) in the eutectic composition to the high temperature side. Therefore, by adding 0.1 to 2.0% by weight of Ti to the Al—Cu—Si alloy, the reliability of the joint between the composite member and the insulating substrate is improved, and brazing is performed at 600 ° C. or lower. A brazing material that can be obtained can be obtained.

  In addition, by preparing the brazing material by mixing the powders of the constituents of the brazing material, the component ratio of the brazing material can be easily changed (or the brazing material is prepared so as to have a predetermined component ratio). it can.

  Furthermore, the joint part of the composite material which has an insulating substrate and carbon as a main component, the joint part of an insulating substrate, and aluminum or an aluminum alloy, etc. can be joined by non-flux.

  Moreover, the semiconductor module of this invention is 0.1 to 2.0 weight% Ti, Cu is 22 to 32 weight%, Si is 3.4-7 as a brazing material of the junction part of an insulated substrate and a composite member. By using a brazing material containing a mixture of Al and inevitable impurities with a balance of 4% by weight, peeling between the insulating substrate and the composite member is less likely to occur even when the heat cycle is repeated. A high-semiconductor module can be obtained.

  In addition, the semiconductor module of the present invention uses a member having a linear expansion coefficient close to that of the insulating substrate for the heat dissipation substrate, thereby causing warpage of the insulating substrate, generation of cracks in the insulating substrate, and bonding between the insulating substrate and the heat dissipation substrate. Surface peeling can be prevented. Also, by providing a heat transfer layer having a linear expansion coefficient close to that of the insulating substrate on the surface of the insulating substrate opposite to the surface to which the heat dissipation substrate is bonded, the linear expansion coefficient of the insulating substrate is provided on both surfaces of the insulating substrate. A member having a coefficient close to is provided. As a result, the occurrence of stress due to the difference in coefficient of linear expansion is reduced, the insulating substrate is not warped, the generation of cracks in the insulating substrate and the separation of the joint surface between the insulating substrate and the heat dissipation substrate (or heat transfer layer) More suppressed.

  The brazing material, the joining method using the brazing material, and the semiconductor module having the joining portion using the brazing material have been described in detail with reference to specific examples. The module is not limited to the above-described embodiment. That is, the brazing material, the joining method using the brazing material, and the semiconductor module of the present invention can be appropriately changed in design within a range that does not impair the characteristics of the present invention. It belongs to a joining method using a brazing material and a semiconductor module.

  For example, in the description of the examples, a form using a brazing material in which powders of respective components constituting the eutectic alloy are mixed is described as an example. However, a brazing material in which Ti powder is mixed with the eutectic alloy powder, Alternatively, a sheet-like brazing material in which a predetermined amount of Ti is mixed with the eutectic alloy component may be used. The solvent added to the mixture of Ti and eutectic Al—Cu—Si powder is not limited to ethanol, and a known solvent may be used as appropriate. Further, the method for forming the brazing material layer is not limited to the coating method, and a spraying method, a screen printing method, or the like can be used by adding an appropriate amount of solvent to the quaternary mixed powder.

  In addition, the bonding atmosphere of the brazing material is not limited to bonding in an argon gas atmosphere, but is reliable by bonding in an inert gas atmosphere such as a nitrogen gas atmosphere or in a vacuum atmosphere. A highly-bonded joint can be obtained.

  Further, in the description of the embodiment, the bonding between the composite member and the aluminum nitride substrate has been described in detail. However, the brazing material and the bonding method using the brazing material according to the present invention can be applied to the composite member and another ceramic substrate (for example, an aluminum oxide substrate). Even when applied to bonding of a silicon nitride substrate or the like, a highly reliable bonding portion can be obtained. Further, since the brazing material and the joining method using the brazing material of the present invention can join the composite member and the insulating substrate, it can be applied to the joining of the composite member and the composite member, and the insulating substrate and the insulating substrate. it is obvious.

  In addition, the brazing material of the present invention can be used for bonding a ceramic substrate and a metal layer because it can bond a metal and a ceramic substrate.

  In addition, when brazing the wiring layer and the heat transfer layer, the heat transfer layer and the insulating substrate, and the insulating substrate and the heat dissipation substrate, surface treatment such as nickel plating is performed in advance on the surface of the composite member that is the heat transfer layer and the heat dissipation substrate. The wettability of the brazing material is improved, and the brazing property between the members can be further improved.

DESCRIPTION OF SYMBOLS 1, 11, 12 ... Semiconductor module 2 ... Semiconductor element 3 ... Wiring layer 4 ... Heat-transfer layer (1st composite member)
5 ... Insulating substrate 6 ... Heat dissipation substrate (second composite member)
7 ... Water-cooled jacket (heatsink)
7a ... Refrigerant flow path 8 ... Bolt 9 ... Brazing material 10 ... Pressing member 13 ... Heat transfer layer 14 ... Heat dissipation substrate 15 ... Stress relaxation layer

Claims (6)

In a brazing material comprising a mixture of Al powder, Cu powder, Si powder, Ti powder,
Ti: 0.1 to 2.0 wt%, Cu: 2 2 to 32 wt%, Si: 3.4 to 7.4 wt%, that Do the balance is Al and inevitable impurities
Brazing material, wherein a call. The brazing material according to claim 1, wherein the brazing material is further mixed with a solvent. The brazing material according to claim 1, wherein the brazing material joins a composite member in which a carbon material is impregnated with aluminum or an aluminum alloy, and an insulating substrate. A composite member obtained by impregnating a carbon material with aluminum or an aluminum alloy, a brazing material made of a mixture of Al powder, Cu powder, Si powder, and Ti powder, Ti: 0.1 to 2.0 % by weight , Cu : 22 to 32 wt%, Si: 3.4 to 7.4 wt%, the balance via Carlo cormorants material such from Al and unavoidable impurities insulating substrate is provided,
A bonding method using a brazing material, wherein the composite member and the insulating substrate are pressure-bonded, and the brazing material is heated and brazed in an inert gas atmosphere or a vacuum atmosphere. A semiconductor element;
A wiring layer provided with the semiconductor element;
An insulating substrate in which the wiring layer is provided via a first composite member in which a carbon material is impregnated with aluminum or an aluminum alloy;
A radiator provided on a surface opposite to the surface on which the wiring layer of the insulating substrate is provided via a second composite member in which a carbon material is impregnated with aluminum or an aluminum alloy;
The joint of the first composite member and the insulating substrate, or at least one of the joint of the second composite member and the insulating substrate will be made of a mixture of Al powder, Cu powder, Si powder, and Ti powder. a timber, Ti: 0.1 to 2.0 wt%, Cu: 22 to 32 wt%, Si: 3.4-7.4 wt%, Carlo cormorants material such from the balance Al and inevitable impurities A semiconductor module characterized in that it is joined with The semiconductor module according to claim 5, wherein a nickel layer is formed on a brazing surface of the first composite member or the second composite member.

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