Molded intelligent power module and method of making the same

Patent metadata

Field	Value
Publication number	US-10396019-B2
Application number	US-201816170895-A
Country	US
Kind code	B2
Filing date	Oct 25, 2018
Priority date	Oct 16, 2016
Publication date	Aug 27, 2019
Grant date	Aug 27, 2019

Abstract

An intelligent power module (IPM) has a first, second, third and fourth die paddles, a first, second, third, fourth, fifth and sixth metal-oxide-semiconductor field-effect transistors (MOSFETs), a tie bar, a metal slug, a plurality of spacers, a plurality of leads and a molding encapsulation. The molding encapsulation encloses the first, second, third and fourth die paddles, the first, second, third, fourth, fifth and sixth MOSFETs, the tie bar and the plurality of spacers. A bottom surface of the metal slug is exposed from the molding encapsulation. A process for fabricating the IPM comprises preparing the first, second, third and fourth die paddles, the first, second, third, fourth, fifth and sixth MOSFETs, the tie bar, the plurality of leads, the metal slug and the plurality of spacers and applying a molding process to form the molding encapsulation.

First claim

The invention claimed is:

1. A method for fabricating an intelligent power module (IPM) for driving a motor, the method comprising the steps of:
providing a leadframe comprising a first, second, third and fourth die paddles and a plurality of leads;
providing a first transistor attached to a top surface of the first die paddle, a second transistor attached to a top surface of the second die paddle, a third transistor attached to a top surface of the third die paddle, a fourth, fifth, and sixth transistors attached to a top surface of the fourth die paddle;
electrically connecting the first, second, third, fourth, fifth, and sixth transistors to the plurality of leads respectively;
providing a metal slug and a plurality of spacers; wherein the plurality of spacers are between the metal slug and the first, second, third and fourth die paddles; and wherein the plurality of spacers separate the metal slug from contacting the first, second, third, and fourth die paddles; and
applying a molding process to form a molding encapsulation enclosing the first, second, third, and fourth die paddles, the first, second, third, fourth, fifth, and sixth transistors and the plurality of spacers.

2. The method of claim 1 , before the step of applying the molding process to form the molding encapsulation,
forming a first, second, third and fourth location pins;
placing the metal slug in a location so that
the first location pin is disposed adjacent to a first side of the metal slug;
the second location pin is disposed adjacent to a second side of the metal slug;
the third location pin is disposed adjacent to a third side of the metal slug; and
the fourth location pin is disposed adjacent to a fourth side of the metal slug.

3. The method of claim 1 , before the step of providing the metal slug and the plurality of spacers,
applying a plurality of wire bonding processes to connect an integrated circuit (IC) to the first, second, third, fourth, fifth, and sixth transistors and a portion of the plurality of leads.

4. The method of claim 1 , before the step of providing the metal slug and the plurality of spacers,
applying a first plurality of wire bonding processes to connect a low voltage integrated circuit (IC) to the first, second and third transistors and a first portion of the plurality of leads; and
applying a second plurality of wire bonding processes to connect a high voltage IC to the fourth, fifth, and sixth transistors and a second portion of the plurality of leads.

5. The method of claim 1 , wherein the step of providing the metal slug and the plurality of spacers comprises the sub-steps of
printing and curing the plurality of spacers on the metal slug so that bottom surfaces of the plurality of spacers directly contact a top surface of the metal slug; and
placing the first, second, third and fourth die paddles on top of the plurality of spacers so that bottom surfaces of the first, second, third and fourth die paddles directly contact top surfaces of the plurality of spacers.

6. The method of claim 1 , after the step of applying the molding process to form the molding encapsulation,
grinding a bottom surface of the molding encapsulation so that the bottom surface of the metal slug is exposed from the molding encapsulation.

Assignees

• Alpha & Omega Semiconductor Cayman Ltd

Inventors

• Niu Zhiqiang
• Suh Bum-Seok
• Cho Wonjin
• Lu Jun

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

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/5525

  comprising copper [Cu] · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title