Power module and inverter equipment

Abstract

The power module includes: a first metallic pattern; a plurality of power devices bonded on the first metallic pattern, each of the plurality of the power devices has a thickness thinner than a thickness of the metallic pattern; a frame member disposed so as to collectively enclose a predetermined number of the power devices on the first metallic pattern; a second metallic pattern disposed outside the frame member; and a resin layer configured to seal the plurality of the power devices and the first and second metallic patterns so as to include the frame member, wherein the frame member suppresses a stress according to a difference between a coefficient of thermal expansion of the metallic pattern and a coefficient of thermal expansion of the power devices. There is provided the power module easy to be fabricated, capable of suppressing the degradation of the bonded portion and improving reliability.

What is claimed is: 
     
         1 . A power module comprising:
 a first metallic pattern;   a plurality of power devices configured to be bonded on the first metallic pattern, each of the plurality of the power devices has a thickness thinner than a thickness of the metallic pattern;   a frame member disposed so as to collectively enclose a predetermined number of the plurality of the power devices on the first metallic pattern;   a second metallic pattern disposed outside the frame member; and   a resin layer configured to seal the plurality of the power devices, the first metallic pattern, and the second metallic pattern so as to include the frame member, wherein   the frame member suppresses a stress according to a difference between a coefficient of thermal expansion of the metallic pattern and a coefficient of thermal expansion of the power devices.   
     
     
         2 . The power module according to  claim 1 , wherein
 a coefficient of thermal expansion of the frame member is smaller than the coefficient of thermal expansion of the metallic pattern.   
     
     
         3 . The power module according to  claim 1 , wherein
 the first metallic pattern is a copper pattern formed on a DBC substrate or a ceramics substrate.   
     
     
         4 . The power module according to  claim 3 , wherein
 the frame member is ceramics, a metal, or a composite material between the ceramics and the metal, a coefficient of thermal expansion of the metal is lower than a coefficient of thermal expansion of the copper pattern.   
     
     
         5 . The power module according to  claim 1 , wherein
 when a value of the coefficient of thermal expansion of the first metallic pattern is 16 ppm/K and a value of the coefficient of thermal expansion of the power device is 3 ppm/K, the frame member has a value of a coefficient of thermal expansion within a range of 2 ppm/K to 10 ppm/K.   
     
     
         6 . The power module according to  claim 1 , wherein
 the frame member is disposed along an edge of the first metallic pattern.   
     
     
         7 . The power module according to  claim 1 , wherein
 the frame member is disposed an inner side than an edge of the first metallic pattern.   
     
     
         8 . The power module according to  claim 1 , wherein
 a planar view shape of the frame members is a rectangle shape; a circular shape; or a shape of a plurality of lines in parallel so as to sandwich the power device.   
     
     
         9 . The power module according to  claim 1 , wherein
 a surface roughening process is applied to a front side surface of the frame member.   
     
     
         10 . The power module according to  claim 1 , wherein
 a thickness of the frame member is substantially the same as a thickness of the first metallic pattern.   
     
     
         11 . The power module according to  claim 1 , wherein
 a thickness of the frame member is thicker than the thickness of the power device.   
     
     
         12 . The power module according to  claim 1 , further comprising
 a first block terminal electrode, one end of the first block terminal electrode being connected to an electrode of the power device, and the other end of the first block terminal electrode being connected to the second metallic pattern so as to get over the frame member.   
     
     
         13 . The power module according to  claim 11 , further comprising:
 a relaying substrate disposed inside the frame member, the relaying substrate connected by a wire to an electrode of the power device; and   a second block terminal electrode, one end of the second block terminal electrode being connected to the relaying substrate, and the other end of the second block terminal electrode being connected to the second metallic pattern so as to get over the frame member.   
     
     
         14 . The power module according to  claim 1 , further comprising
 an insulating mounting substrate, wherein   the first metallic pattern and the second metallic pattern are disposed on the mounting substrate.   
     
     
         15 . The power module according to  claim 14 , further comprising
 a heat sink, wherein   the mounting substrate is disposed on the heat sink.   
     
     
         16 . The power module according to  claim 15 , wherein
 the mounting substrate further comprises a third metallic pattern, the third metallic pattern disposed on a surface opposite to a surface where the first metallic pattern is disposed, and   the third metallic pattern is connected to the heat sink.   
     
     
         17 . The power module according to  claim 14 , wherein
 the resin layer covers a side surface of the mounting substrate.   
     
     
         18 . The power module according to  claim 1 , wherein
 a value of a coefficient of thermal expansion of the resin layer is within a range of 12 ppm/K to 14 ppm/K.   
     
     
         19 . The power module according to  claim 1 , wherein
 the power device comprises one semiconductor chip selected from the group consisting of semiconductor chips of IGBT, diode, Si based MISFET, SiC based MISFET, and GaNFET.   
     
     
         20 . The power module according to  claim 1 , wherein
 the first metallic pattern is one substrate selected from the group consisting of a DBA substrate and an AMB substrate.   
     
     
         21 . The power module according to  claim 1 , wherein
 a cross-sectional structure of the frame member has one structure selected from the group consisting of an I-shaped structure, a T-shaped structure, an inverted-L-shaped structure, and Γ-shaped structure.   
     
     
         22 . Inverter equipment comprising
 a circuit in which a plurality of switching elements are connected in series between power terminals and a connection unit of the plurality of the switching elements is used as an output, wherein   the inverter equipment is configured to mount at least one power module according to  claim 1  as the switching elements.   
     
     
         23 . The inverter equipment according to  claim 22 , wherein
 the plurality of the switching elements are connected to an external terminal, via respective pillar electrodes bonded to respective upper surfaces thereof and an upper surface plate electrode configured to commonly connect the pillar electrode predetermined.