Capacitive Isolation Assembly for Hybrid Semiconductor Packages

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Solution Overview

Problem

Existing hybrid packages face challenges in providing cost-effective voltage isolation between semiconductor dies, with current methods being either costly or unreliable, such as using laser emitting diodes or separate packages, which increase costs and risk damage to lower voltage dies from higher voltage dies.

Innovation Solution

A capacitive coupling device is implemented within the package, where a first semiconductor die acts as a transmitter and a second die as a receiver, both attached to a split die attach pad with a dielectric in between, allowing for efficient communication without conductive contact and preventing voltage damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laser emitting diodes are used for isolation, then voltage isolation between semiconductor dies is achieved, but cost increases and reliability decreases

Engineering Contradiction:

Improvevoltage isolation reliabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

A capacitive isolation device is introduced as an intermediary component between the high voltage semiconductor die and the low voltage controller die. This device provides galvanic isolation through capacitance, blocking direct electrical contact while allowing signal transmission, thereby achieving reliable voltage isolation at lower cost compared to laser emitting diodes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the optical isolation mechanism (laser emitting diodes) with an electrical capacitive isolation mechanism. This substitution eliminates the need for complex optical components and their associated control circuits, reducing manufacturing cost while maintaining isolation reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If two separate packages are used with isolation device, then voltage isolation is achieved, but device complexity and cost increase

Engineering Contradiction:

Improvevoltage isolationVSAvoidpackage structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the high voltage semiconductor die, the low voltage controller die, and the capacitive isolation device into a single integrated package. This consolidation eliminates the need for separate packages and external isolation devices, reducing overall device complexity while maintaining effective voltage isolation between the dies.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The capacitive isolation device serves multiple functions within the single package: it provides voltage isolation, enables signal transmission between dies of different voltage levels, and reduces the overall package complexity by integrating multiple functions into one component.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If direct conductive contact is used between semiconductor dies, then communication efficiency is improved, but voltage damage risk increases

Engineering Contradiction:

Improvecommunication efficiencyVSAvoidvoltage damage risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The capacitive isolation device acts as an intermediary that enables communication between the high voltage and low voltage dies without direct conductive contact. It transmits signals through capacitance, maintaining communication efficiency while blocking harmful voltage spikes and electrical noise from damaging the low voltage controller die.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This solution provides reliable and cost-effective isolation between semiconductor dies, enabling efficient communication without the risks of voltage damage, while maintaining a compact hybrid package design.

Implementation Method 1

a capacitive coupling device is implemented within the package, where a first semiconductor die acts as a transmitter and a second die as a receiver, both attached to a split die attach pad with a dielectric in between

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

a second plate separated from the first plate by a dielectric

Methodology Applied

Scientific EffectDielectric isolation: Dielectric

Data Source

PatentUS20240021546A1Apparatus including an isolation assembly

Publication Date: 2024.01.18 TEXAS INSTRUMENTS INC

AI summary

Described examples include an apparatus including a package substrate having a die attach pad and a first semiconductor die on the die attach pad, the first semiconductor die including a transmitter. The apparatus also includes an assembly having a first plate coupled to the transmitter, a second plate separated from the first plate by a dielectric and a second semiconductor die on the die attach pad, the second semiconductor die including a receiver coupled to the second plate.