Power module and fabrication method for the same

Patent metadata

Field	Value
Publication number	US-2016141231-A1
Application number	US-201615003156-A
Country	US
Kind code	A1
Filing date	Jan 21, 2016
Priority date	Jul 22, 2013
Publication date	May 19, 2016
Grant date	—

Abstract

A power module includes: an insulating layer; a leadframe disposed on the insulating layer; a semiconductor chip disposed on the leadframe; and a mold resin formed so as to cover the semiconductor chip and at least a part of the metal layer, wherein a groove into which a part of the insulating layer is inserted is formed on a surface of the leadframe facing the insulating layer. Accordingly, there can be provided the power module with improved reliability so that the insulating layer and the leadframe may be hardly deviated from each other even if external force is applied thereon; and a fabrication method for such a power module.

First claim

What is claimed is:

1 . A power module comprising:
an insulating layer; a metal layer disposed on the insulating layer; a semiconductor chip disposed on the metal layer; and a mold resin formed so as to cover the semiconductor chip and at least a part of the metal layer, wherein a groove into which a part of the insulating layer is inserted is formed on a surface of the metal layer facing the insulating layer.

2 . The power module according to claim 1 , wherein
a plurality of the groove are formed outside a region of the metal layer opposite to the semiconductor chip.

3 . The power module according to claim 2 , wherein
the region is a region where an angle between a line and a flat surface of the metal layer is equal to or less than 45 degrees, the line connecting between an edge part of the semiconductor chip and an edge part of the groove nearest to the semiconductor chip among the plurality of the grooves.

4 . The power module according to claim 2 , wherein
the plurality of the groove are formed only outside a region of the metal layer opposite to the semiconductor chip.

5 . The power module according to claim 1 , wherein:
a cross-sectional shape of the groove is at least one shape selected from the group consist of a rectangle shape, a semicircle shape, a semi-ellipse shape, triangular shape, and a wedge shape; and a depth of the groove is shallower than a half of a thickness of the metal layer.

6 . The power module according to claim 1 , wherein
the groove is formed along in one direction or is formed in a lattice-like shape.

7 . The power module according to claim 1 , wherein
a surface roughening process is applied on a surface of the metal layer facing the insulating layer.

8 . The power module according to claim 1 , wherein
the insulating layer is formed of a material softer than the metal layer.

9 . The power module according to claim 8 , wherein
a hardness of the insulating layer is softer than A40 in durometer hardness.

10 . The power module according to claim 1 , wherein
the insulating layer is formed of an organic material.

11 . The power module according to claim 1 , wherein
the insulating layer is formed of a silicone based resin.

12 . The power module according to claim 1 , wherein
the insulating layer is filled up with a high thermally-conductive filler.

13 . The power module according to claim 12 , wherein
the filler is at least one selected from the group consist of aluminium oxide, silicon oxide, aluminum nitride, silicon nitride, boron nitride, beryllia, and magnesia.

14 . The power module according to claim 12 , wherein
the mold resin is formed so as to cover at least a part of a side surface of the insulating layer and a corner portion of the metal layer.

15 . The power module according to claim 14 , wherein
an edge part of the insulating layer is intervened between the mold resin and the metal layer.

16 . The power module according to claim 1 , wherein
the mold resin is formed so as to cover at least a part of a side surface of the insulating layer and a corner portion of the metal layer.

17 . The power module according to claim 16 , wherein:
the semiconductor chip is formed of one selected from the group consist of an SiC based power device, a GaN based power device, and an AlN based power device; and a current change rate di/dt thereof is larger than 3×10 8 (A/s).

18 . The power module according to claim 1 , wherein
the power module is formed as any one selected from the group consist of 1-in-1 module, 2-in-1 module, 4-in-1 module, and 6-in-1 module.

19 . A fabrication method for a power module comprising:
forming a groove on a bottom surface of a leadframe; bonding a semiconductor chip to the leadframe with a conductive bonding material; electrically connecting the semiconductor chip and the leadframe to each other using a connecting member; disposing the leadframe on a metallic mold and then forming an insulating layer on a bottom surface of the leadframe, the insulating layer formed so as to be inserted into the bottom surface of the leadframe; and after curing the insulating layer, closing the metallic mold, and then pouring a mold resin therein in order to mold the leadframe, the conductive bonding material, the semiconductor chip, and the connecting member.

20 . The fabrication method for a power module according to claim 19 , wherein
the step of forming the insulating layer on the bottom surface of the leadframe comprises forming the insulating layer so as to cover a corner portion of the leadframe.

21 . A fabrication method for a power module comprising:
forming a groove on a bottom surface of a leadframe; bonding a semiconductor chip to the leadframe with a conductive bonding material; electrically connect the semiconductor chip and the leadframe to each other using a connecting member; disposing the leadframe on a metallic mold and then forming an insulating layer on a bottom surface of the leadframe; and after curing the insulating layer, closing the metallic mold, and then pouring a mold resin therein in order to mold the leadframe, the conductive bonding material, the semiconductor chip, and the connecting member, wherein the step of forming the insulating layer on the bottom surface of the leadframe comprises forming so that a surface of the mold resin and a surface of the leadframe are flush with each other at a corner portion of the leadframe, and then forming the insulating layer on the surface of the mold resin and the surface of the leadframe which are flush with each other.

Assignees

• Rohm Co Ltd

Inventors

• Yoshihara Katsuhiko
• Saito Masao

Classifications

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W90/736

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W74/111

  the semiconductor body being completely enclosed · CPC title

• H10W72/5363

  the connected ends being wedge-shaped · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title