Power module substrate, power module, and method for manufacturing power module substrate

Abstract

A power module substrate includes: a ceramics substrate having a surface; and a metal plate connected to the surface of the ceramics substrate, composed of aluminum, and including Cu at a joint interface between the ceramics substrate and the metal plate, wherein a Cu concentration at the joint interface is in the range of 0.05 to 5 wt %.

1 - 29 . (canceled) 
     
     
         30 . A power module substrate comprising:
 a ceramics substrate having a surface;   a metal plate connected to the surface of the ceramics substrate via a brazing filler metal including Si, composed of aluminum;   Cu introduced into the joint interface between the ceramics substrate and the metal plate, wherein   the metal plate includes Si and Cu; and   a Si concentration is in the range of 0.05 to 0.5 wt % and a Cu concentration is in the range of 0.05 to 1.0 wt %, in a portion which is close to the joint interface of the metal plate.   
     
     
         31 . The power module substrate according to  claim 30 , wherein
 a width of the ceramics substrate is greater than a width of the metal plate;   an aluminum phase in which Si and Cu are included in aluminum, a Si phase in which a content rate of Si is greater than or equal to 98 wt %, and an eutectic phase composed of a ternary eutectic structure including Al, Cu, and Si, are formed at an end portion in a width direction of the metal plate.   
     
     
         32 . The power module substrate according to  claim 31 , wherein
 precipitate particles composed of a compound including Cu precipitate in the eutectic phase.   
     
     
         33 . The power module substrate according to  claim 30 , further comprising:
 a high-Si concentration section formed at the joint interface between the metal plate and the ceramics substrate, having a Si concentration that is more than five times the Si concentration in the metal plate, wherein   the ceramics substrate is composed of AlN or Al 2 O 3 .   
     
     
         34 . The power module substrate according to  claim 30 , further comprising:
 a high-oxygen concentration section formed at the joint interface between the metal plate and the ceramics substrate, having an oxygen concentration that is greater than oxygen concentrations in the metal plate and in the ceramics substrate, and having a thickness of less than or equal to 4 nm, wherein   the ceramics substrate is composed of AlN or Si 3 N 4 .   
     
     
         35 . A power module comprising:
 a power module substrate according to  claim 30 ; and   an electronic component mounted on the power module substrate.   
     
     
         36 . A method for manufacturing a power module substrate, comprising:
 preparing a ceramics substrate having a connection face, a metal plate composed of aluminum, and a brazing filler metal including Si;   stacking the ceramics substrate and the metal plate in layers with the brazing filler metal interposed therebetween;   heating the ceramics substrate, the brazing filler metal, and the metal plate which are stacked in layers in a state where a pressure is applied thereon;   forming a fusion aluminum layer at a boundary face between the ceramics substrate and the metal plate by melting the brazing filler metal; and   solidifying the fusion aluminum layer, wherein   Cu is adhered to at least one of the connection face of the ceramics substrate and a face of the brazing filler metal opposing the ceramics substrate before stacking the ceramics substrate and the metal plate in layers with the brazing filler metal interposed therebetween.   
     
     
         37 . The method for manufacturing a power module substrate according to  claim 36 , wherein
 Cu is adhered to at least one of the connection face of the ceramics substrate and a face of the brazing filler metal opposing the ceramics substrate by an evaporation method or a sputtering method in the adhering of Cu.