# US 2014/0151718 A1 · Semiconductor device and manufacturing method thereof

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- Number: US 2014/0151718 A1
- Document ID: US20140151718A1
- Status: Published application
- Kind: A1
- Application number: 13/951,327
- Filed: 2013-07-25
- Published: 2014-06-05
- Earliest claimed: 2012-11-30
- Assignees: Mitsubishi Electric Corporation
- Applicants: Mitsubishi Electric Corporation
- Inventors: Tatsunori YANAGIMOTO
- Web page: https://patentgrep.com/patent/US20140151718A1

## CPC

- H10W 70/411: {Chip-supporting parts, e.g. die pads}
- H10W 70/048: {Mechanical treatments, e.g. punching, cutting, deforming or cold welding}
- H10W 90/811: {Multiple chips on leadframes}
- H10W 72/884: {Die-attach connectors and bond wires}
- H10W 90/736: {between a chip and a stacked lead frame, conducting package substrate or heat sink}
- H10W 90/753: {between laterally-adjacent chips}
- H10W 90/756: {between a chip and a stacked lead frame, conducting package substrate or heat sink}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A semiconductor device according to the present invention includes a die pad, a semiconductor element joined to an upper surface of the die pad, and a resin sheet making close contact with a lower surface of the die pad, wherein the semiconductor element is resin-sealed together with the die pad and the resin sheet, wherein a recess is formed in the lower surface of the die pad, and a part of the resin sheet is filled into the recess bring the resin sheet into close contact with the lower surface of the die pad including an inside of the recess.

## Claims

### Claim 1

A semiconductor device comprising:
a die pad;
a semiconductor element joined to an upper surface of said die pad; and
a resin sheet making close contact with a lower surface of said die pad, wherein said semiconductor element is resin-sealed together with said die pad and said resin sheet,
a recess is formed in the lower surface of said die pad, and
a part of said resin sheet is filled into said recess so that said resin sheet makes close contact with the lower surface of said die pad including an inside of said recess.

### Claim 2 (depends on 1)

The semiconductor device according to claim 1, wherein a cross section of said recess is V-shaped.

### Claim 3 (depends on 1)

The semiconductor device according to claim 1, wherein a width of the inside of said recess is larger than a width of an opening of said recess.

### Claim 4 (depends on 1)

The semiconductor device according to claim 1, wherein said recess extends from one side to the other side of the lower surface of said die pad.

### Claim 5 (depends on 4)

The semiconductor device according to claim 4, wherein said recess is provided radially from a region overlapped with said semiconductor element in plan view.

### Claim 6 (depends on 1)

The semiconductor device according to claim 1, wherein
a heat dissipation filler is mixed into said resin sheet, and
a density of said filler in a portion of said resin sheet filled into said recess is lower than a density of said filler in the rest portion of the resin sheet.

### Claim 7 (depends on 1)

The semiconductor device according to claim 1, wherein said semiconductor element is a SiC semiconductor element.

### Claim 8

A semiconductor device manufacturing method comprising the steps of:
(a) forming a recess in a lower surface of a die pad;
(b) after said step (a), joining a semiconductor element to an upper surface of said die pad;
(c) after said step (b), arranging a resin sheet in a mold held at a temperature at which a sealing resin can be melted to arrange said die pad on an upper surface of the resin sheet; and
(d) after said step (c), injecting the sealing resin into said mold and pressing the lower surface of said die pad onto said resin sheet by a pressure of said sealing resin injected into said mold to fill a part of said resin sheet into said recess so that said resin sheet makes close contact with the lower surface of said die pad including an inside of said recess, and simultaneously, resin-sealing said semiconductor element by said sealing resin together with said die pad and said resin sheet.

### Claim 9 (depends on 8)

The semiconductor device manufacturing method according to claim 8, wherein coining is performed a plurality of times in said step (a) so that a width of the inside of said recess is formed to be larger than a width of an opening of said recess.