Semiconductor device and method of manufacturing semiconductor device

Patent metadata

Field	Value
Publication number	US-9466548-B2
Application number	US-201214358917-A
Country	US
Kind code	B2
Filing date	Feb 22, 2012
Priority date	Feb 22, 2012
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

A semiconductor device incorporating a heat spreader and improved to inhibit dielectric breakdown is provided. The semiconductor device has an electrically conductive heat spreader having a bottom surface, a sheet member having a front surface and a back surface electrically insulated from each other, IGBTs and diodes fixed on the heat spreader and electrically connected thereto, and a molding resin. The front surface contacts with the bottom surface and has a peripheral portion jutting out from edges thereof. The molding resin encapsulates the front surface of the sheet member, the heat spreader and the semiconductor elements. At least part of the back surface of the sheet member is exposed out of the molding resin. The heat spreader has, at a corner of its bottom surface, corner portions having a beveled shape or a curved-surface shape as seen in plan and having a rectangular shape as seen in section.

First claim

The invention claimed is:

1. A semiconductor device comprising:
a heat spreader including a bottom surface and being electrically conductive;
a sheet member including a front surface and a back surface, the front and back surfaces electrically insulated from each other, the front surface contacting the bottom surface of the heat spreader, the sheet member including a peripheral portion that juts out from an edge of the bottom surface;
a semiconductor element fixed on the heat spreader and electrically connected to the heat spreader; and
an encapsulation resin body in which the front surface of the sheet member, the heat spreader, and the semiconductor element are encapsulated, and at least a portion of the back surface of the sheet member exposed from the encapsulation resin body;
wherein the heat spreader includes a corner portion at a corner of the bottom surface, the corner portion includes a C-beveled shape as seen in the plan view, the corner portion is rectangular as seen in the section of the heat spreader.

2. A semiconductor device comprising:
a heat spreader including a bottom surface and being electrically conductive;
a sheet member including a front surface and a back surface, the front and back surfaces electrically insulated from each other, the front surface contacting the bottom surface of the heat spreader, the sheet member including a peripheral portion that juts out from an edge of the bottom surface;
a semiconductor element fixed on the heat spreader and electrically connected to the heat spreader; and
an encapsulation resin body in which the front surface of the sheet member, the heat spreader, and the semiconductor element are encapsulated, and at least a portion of the back surface of the sheet member exposed from the encapsulation resin body;
wherein the front surface of the peripheral portion includes a layer formed of an electrically insulating coating material, the layer includes at least one of higher insulation quality electrical insulating property and higher adhesion to the front surface of the sheet member compared with a material of the encapsulation resin body.

3. The semiconductor device according to claim 2 , wherein
the electrically insulating coating material is a material selected from the group consisting of polyimide, polyamide and a polyfunctional epoxy polymer.

4. A method of manufacturing of a semiconductor device, the method comprising the steps of:
preparing a heat spreader including a bottom surface and being electrically conductive, a semiconductor element to be fixed on the heat spreader, and a sheet member including a front surface and a back surface, the front and back surfaces electrically insulated from each other;
bending a peripheral portion of the sheet member to the heat spreader side by bent portion forming means, after placing the sheet member, the heat spreader and the semiconductor element fixed on the heat spreader into a cavity of a mold, placing the sheet member on a cavity bottom surface of the mold so that the back surface faces the cavity bottom surface, and placing the heat spreader on the front surface of the sheet member to provide the peripheral portion that juts out from an edge of the bottom surface of the heat spreader; and
performing an encapsulating process, in a state where bending on the peripheral portion is completed, so that the front surface of the sheet member, the back surface of the peripheral portion, the heat spreader, and the semiconductor element are encapsulated, and at least a portion of the back surface of the sheet member is exposed.

5. The method of manufacturing of a semiconductor device according to claim 4 , wherein the bent portion forming means is a projection provided for the back surface of an end portion of the sheet member.

6. The method of manufacturing of a semiconductor device according to claim 4 , wherein the bent portion forming means is a pin provided in the cavity bottom surface in the mold and capable of projecting into the cavity.

7. The method of manufacturing of a semiconductor device according to claim 4 , wherein the bent portion forming means is a projecting portion provided on the cavity bottom surface in the mold.

8. A semiconductor device comprising:
a heat spreader including a bottom surface and being electrically conductive;
a sheet member including a front surface and a back surface, the front and back surfaces electrically insulated from each other, the front surface contacting the bottom surface of the heat spreader, the sheet member including a peripheral portion that juts out from an edge of the bottom surface;
a semiconductor element fixed on the heat spreader and electrically connected to the heat spreader; and
an encapsulation resin body in which the front surface of the sheet member, the heat spreader, and the semiconductor element are encapsulated, and at least a portion of the back surface of the sheet member exposed from the encapsulation resin body;
wherein the peripheral portion includes a smaller-thickness portion in the back surface, the smaller-thickness portion is a portion reduced in thickness to a tip of the peripheral portion so that a step is produced, and the step recesses the front surface side.

9. A semiconductor device comprising:
a heat spreader including a bottom surface and being electrically conductive;
a sheet member including a front surface and a back surface, the front and back surfaces electrically insulated from each other, the front surface contacting the bottom surface of the heat spreader, the sheet member including a peripheral portion that juts out from an edge of the bottom surface;
a semiconductor element fixed on the heat spreader and electrically connected to the heat spreader; and
an encapsulation resin body in which the front surface of the sheet member, the heat spreader, and the semiconductor element are encapsulated, and at least a portion of the back surface of the sheet member exposed from the encapsulation resin body;
wherein the front surface of the peripheral portion includes at least one of a projecting portion extending from the front surface or a recess formed in the front surface.

10. The semiconductor device according to claim 9 , wherein the at least one projecting portion includes a step projecting the front surface side compared with a central portion of the sheet member, and the step is provided at least in a vicinity of a corner of the bottom surface in the peripheral portion.

11. The semiconductor device according to claim 9 , wherein the front surface of the peripheral portion includes a projection-recess portion having projection and recess so that the front surface of the peripheral portion has larger surface roughness than that of the front surface of a central portion of the sheet member,
the at least one projecting portion is the projection of the projection-recess portion, and
the at least one recess is the recess of the projection-recess portion.

12. The semiconductor device according to claim 9 , wherein the at least one projecting portion includes an up-down form provided in the peripheral portion and projecting to a side of a surface contacting to the encapsulation resin body.

13. The semiconductor device according to claim 9 , wherein the at least one recess includes a plurality of dimples formed on the peripheral portion.

14. A semiconductor device comprising:
a heat spreader including a bottom surface and being electrically conductive;
a sheet member including a front surface and a back surface, the front and back surfaces electrically insulated from each other, the front surface contacting the bottom surface of

Assignees

• Sakamoto Ken
• Shikano Taketoshi
• Sasaki Taishi
• Mitsubishi Electric Corp

Inventors

• Sakamoto Ken
• Shikano Taketoshi
• Sasaki Taishi

Classifications

• H10W90/756

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

• H10W90/753

  between laterally-adjacent chips · CPC title

• H10W90/736

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

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/5445

  being orthogonal to a side surface of the chip, e.g. parallel arrangements · CPC title