Wiring board, semiconductor device and method for manufacturing the same
A semiconductor device including a semiconductor element 1 having an active element region 1 a , a plurality of element electrodes 2 formed on a principal face of the semiconductor element, external terminals 6 and 7 connected to one or more element electrodes via connection members 8 and 9 , one or more first heat-dissipation protrusions 4 formed on the principal face of the semiconductor element, an insulation resin layer 10 covering the principal face of the semiconductor element and the first heat-dissipation protrusions, and a heat-dissipation medium 11 contacting a face of the insulation resin layer on a side opposite to a side contacting front faces of the first heat-dissipation protrusions. At least a part of the active element region is included in a region below a bottom face of the first heat-dissipation protrusion, the first heat-dissipation protrusion is not connected to the external terminal within the active element region, a thermal conductivity of the first heat-dissipation protrusion is larger than a thermal conductivity of the insulation resin layer, and a thickness of the insulation resin layer from the front face of the first heat-dissipation protrusion to the heat-dissipation medium is thinner than a thickness of the insulation resin layer from the principal face of the semiconductor element to the heat-dissipation medium. Thereby, it is possible to improve the speed of dissipating heat from the active element region of the mounted semiconductor element to the heat-dissipation medium.
1. A semiconductor device comprising:
a semiconductor element having an active element region;
a plurality of element electrodes formed on a principal face of the semiconductor element;
an external terminal connected to the one or more element electrodes via a connection member;
one or more first heat-dissipation protrusions formed on the principal face of the semiconductor element;
an insulation resin layer covering the principal face of the semiconductor element and the first heat-dissipation protrusion; and
a heat-dissipation medium contacting a face of the insulation resin layer on a side opposite to a side contacting a front face of the first heat-dissipation protrusion,
wherein at least a part of the active element region is included in a region below a bottom face of the first heat-dissipation protrusion,
the first heat-dissipation protrusion is not connected to the external terminal within the active element region,
a thermal conductivity of the first heat-dissipation protrusion is larger than a thermal conductivity of the insulation resin layer, and
a thickness of the insulation resin layer from the front face of the first heat-dissipation protrusion to the heat-dissipation medium is thinner than a thickness of the insulation resin layer from the principal face of the semiconductor element to the heat-dissipation medium.
2. The semiconductor device according to claim 1 , wherein the first heat-dissipation protrusion is formed so as to extend from above the inside of the active element region to the outside thereof and is connected to the external terminal outside the active element region.
3. The semiconductor device according to claim 1 , wherein the first heat-dissipation protrusion contains the same material as that of the connection member.
4. The semiconductor device according to claim 1 , wherein a thermal conductivity of the heat-dissipation medium is larger than the thermal conductivity of the insulation resin layer.
5. The semiconductor device according to claim 1 ,
wherein the heat-dissipation medium is a wiring board,
the semiconductor element is flip-chip mounted on the wiring board,
the external terminal is formed of a part of a conductive wiring formed on the wiring board,
the first heat-dissipation protrusion is formed so as to extend from above the inside of the active element region to the outside thereof and is connected to the external terminal outside the active element region, and
the conductive wiring is formed so as to extend from a region opposed to the first heat-dissipation protrusion via end portions of the semiconductor element to a region where the semiconductor element is not flip-chip mounted.
6. The semiconductor device according to claim 1 ,
wherein the heat-dissipation medium is a wiring board,
the semiconductor element is flip-chip mounted on the wiring board,
the wiring board comprises:
a plurality of first conductive wirings formed on an upper face of the wiring board;
a second conductive wiring formed on the wiring board at a position opposed to a region where the first heat-dissipation protrusion is formed; and
a plurality of second heat-dissipation protrusions formed on the second conductive wiring,
a part of the first conductive wiring functions as the external terminal and is connected to the element electrode via the connection member,
each top portion of the second heat-dissipation protrusions is surrounded by adjacent top portions of the first heat-dissipation protrusions and the respective side faces are opposed to each other without contacting with each other, and
an insulation resin is filled in a space between the second heat-dissipation protrusions and the first heat-dissipation protrusions.
7. The semiconductor device according to claim 6 , wherein an end portion of the first conductive wiring on a side connected to the element electrode via the connection member extends toward a center of the semiconductor element so as to form the second conductive wiring.
8. The semiconductor device according to claim 1 ,
wherein the heat-dissipation medium is a wiring board,
the semiconductor element is flip-chip mounted on the wiring board,
the wiring board comprises:
a plurality of first conductive wirings formed on an upper face of the wiring board;
a second conductive wiring formed on the wiring board at a position opposed to a region where the first heat-dissipation protrusion is formed; and
a plurality of second heat-dissipation protrusions formed on the second conductive wiring,
the element electrode and the first conductive wiring are connected via the connection member,
each top portion of the second heat-dissipation protrusions is surrounded by adjacent top portions of the first heat-dissipation protrusions and the respective side faces are opposed to each other and in contact with each other, and
an insulation resin is filled in a space between the second heat-dissipation protrusions and the first heat-dissipation protrusions.
9. A method for manufacturing a semiconductor device, comprising:
forming a first conductive wiring and a second conductive wiring on a wiring board;
forming a plurality of wiring protrusion electrodes on the first conductive wiring and a plurality of second heat-dissipation protrusions on the second conductive wiring in the same thickness;
forming an element protrusion electrode on each of a plurality of element electrodes formed on a principal face of a semiconductor element and a first heat-dissipation protrusion on each of a plurality of heat-dissipation electrodes formed on the principal face of the semiconductor element in the same thickness using a material having a hardness higher than a hardness of a material of the wiring protrusion electrodes;
arranging the wiring board and the semiconductor element so that the wiring protrusion electrode and the corresponding element protrusion electrode are opposed to each other, and the first heat-dissipation protrusion and the second heat-dissipation protrusion establish a horizontal positional relationship in which a top portion of one of the heat-dissipation protrusions is surrounded by adjacent top portions of the other heat-dissipation protrusion; and
flip-chip mounting the semiconductor element on the wiring board by connecting the element protrusion electrode and the wiring protrusion electrode while squashing the top portion of the wiring protrusion electrode, in such a manner as to arrange the top portion of the first heat-dissipation protrusion and the top portion of the second heat-dissipation protrusion at a position where the respective side faces are opposed to each other.