Semiconductor Package Layout Using Eddy Currents to Cut Resistance

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Solution Overview

Problem

Semiconductor packages face increased resistance and power losses due to skin and proximity effects at medium frequency ranges (300 kHz to 3 MHz), which existing technologies fail to adequately mitigate.

Innovation Solution

Incorporating a metallic member that is inductively coupled but electrically resistively insulated within the semiconductor package, which induces eddy currents to redistribute current flow and reduce resistance by mitigating parasitic electromagnetic effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional semiconductor package structure is used, then the package is suitable for low frequency applications, but the resistance increases and power losses occur at medium frequency ranges due to skin and proximity effects

Engineering Contradiction:

Improvepackage resistanceVSAvoidpower losses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent introduces a metallic member that is intentionally left electrically isolated from other conductive parts, allowing parasitic eddy currents to be induced in this member. These eddy currents create a beneficial electromagnetic effect that counteracts the harmful skin and proximity effects in the connector, thereby reducing overall resistance and power losses at medium frequencies

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The metallic member acts as an intermediary element between the connector and the mold compound. It is positioned to be inductively coupled with the connector but electrically insulated from it, serving as a mediating structure that manipulates electromagnetic fields to reduce parasitic effects without direct electrical connection

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the metallic member is electrically connected to the connector, then direct current flow is improved, but parasitic electromagnetic effects increase due to additional current paths

Engineering Contradiction:

Improveelectrical connectionVSAvoidparasitic electromagnetic effects

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The metallic member serves as an intermediary that provides electromagnetic interaction without electrical connection. It is positioned to be inductively coupled with the connector but electrically insulated from it, serving as a mediating structure that manipulates electromagnetic fields to reduce parasitic effects without direct electrical connection

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct electrical mechanical connection with electromagnetic induction. Instead of physically connecting the metallic member to the connector for current flow, it uses inductive coupling where the alternating magnetic field induces eddy currents in the isolated metallic member to achieve the desired electromagnetic effect

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution reduces package resistance by up to 40% and power losses, making the semiconductor package suitable for medium frequency applications by enhancing current homogeneity.

Implementation Method 1

the metallic member is inductively coupled to the connector and which is electrically resistively insulated from the connector

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

eddy currents are induced in the metallic member by AC source currents flowing in the connector

Methodology Applied

Scientific EffectEddy currents: Eddy Currents

Implementation Method 3

the skin effect in the connector leads to concentration of electric current near the connector surface and a reduction of the effective cross section area

Methodology Applied

Scientific EffectSkin effect: Skin Effect

Implementation Method 4

inductive coupling between currents in the connector and other parts of the package such as the leadframe and the metallization of the semiconductor die, causes proximity effects resulting concentration of current on the inner side of the connector

Methodology Applied

Scientific EffectProximity effect:

Implementation Method 5

Eddy currents, that are induced in the die pad and leads and also in the die metallization, increase power losses in these parts

Methodology Applied

Scientific EffectEddy currents: Eddy Currents

Data Source

PatentUS20230420393A1Semiconductor package

Publication Date: 2023.12.28 INFINEON TECH AUSTRIA AG

AI summary

A semiconductor package includes: a semiconductor die having opposing first and second surfaces, a first contact pad on the first surface, and a second contact pad on the second surface; a die pad and at least one lead spaced apart from the die pad, the first contact pad of the die being mounted on the die pad and the second contact pad being electrically connected to the at least one lead by a connector; a mold compound covering the die, connector, and an upper surface of the die pad and of the at least one lead; and a metallic member inductively coupled to the connector and electrically resistively insulated from the connector. The metallic member includes a web portion arranged above the second surface of the die and at least one peripheral rim portion that extends from the web portion in a direction towards the first surface of the die.