Optical Interconnection Structures for Semiconductor Packages

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Solution Overview

Problem

The integration density of semiconductor devices is limited by the increasing number of signal paths in stacked packages, making it difficult to achieve high capacitive stacked packages with efficient signal transmission.

Innovation Solution

A semiconductor package with optical interconnection structures, where a first and second transceiver are disposed on the top and bottom surfaces of an interposer, respectively, allowing optical communication between them, reducing the need for additional interconnection lines and through vias, and enabling efficient signal transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of stacked semiconductor chips is increased to process large amounts of data, then the data processing capacity is improved, but the number of signal paths increases proportionally, requiring reduced line width and pitch of metal interconnection lines

Engineering Contradiction:

Improvedata processing capacityVSAvoidsignal path complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces electrical signal transmission through metal interconnection lines with optical signal transmission through optical fibers. This substitution eliminates the need for reduced line width and pitch constraints, as optical signals do not suffer from the same electrical interference and signal integrity issues as electrical signals in densely packed interconnection lines.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces optical transmitters and optical receivers as intermediary devices between stacked semiconductor chips. These intermediaries convert electrical signals to optical signals for transmission through the interposer, and then convert them back to electrical signals at the destination, enabling high-capacitive stacked packages without the signal path complexity constraints of direct electrical connections.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If the line width and pitch of metal interconnection lines are reduced to accommodate more signal paths, then the integration density is improved, but the manufacturing precision requirements increase

Engineering Contradiction:

Improveintegration densityVSAvoidline width and pitch precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent substitutes optical interconnection structures for electrical metal interconnection lines. This replacement eliminates the need for extremely fine line width and pitch dimensions, as optical fibers can be routed with much larger dimensions that are easier to manufacture and align, thereby reducing manufacturing precision requirements while maintaining high integration density.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transitions from two-dimensional planar metal interconnection lines on the package substrate to three-dimensional optical routing through the interposer. This dimensional change allows optical signals to pass through the vertical thickness of the interposer, providing additional routing freedom and reducing the need for densely packed lateral interconnection lines.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If more metal interconnection lines are added to support increased signal paths, then the data transmission capacity is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvesignal transmission capacityVSAvoidmanufacturing ease

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent replaces the need for numerous metal interconnection lines with a smaller number of optical interconnection structures. Optical transmitters and receivers can handle high data transmission capacities through parallel optical channels, reducing the total number of interconnection structures needed and simplifying the manufacturing process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent makes the interposer serve multiple functions: it acts as both a mechanical support structure for stacking semiconductor chips and as an optical waveguide for signal transmission. This multi-functionality reduces the need for separate dedicated interconnection structures, thereby easing manufacturing complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 approach improves signal transmission speed and reduces the complexity of electrical connections, allowing for higher performance and increased integration density in semiconductor packages.

Implementation Method 1

The second optical transmitter and the second optical receiver optically communicate with the first optical transmitter and the first optical receiver through optical signals that permeate the interposer

Methodology Applied

Scientific EffectOptical signal transmission: Light

Data Source

PatentUS9906312B2Semiconductor packages with optical interconnection structures, memory cards including the same, and electronic systems including the same

Publication Date: 2018.02.27 SK HYNIX INC

AI summary

A semiconductor package includes a first transceiver disposed on a top surface of a substrate; and a second transceiver disposed on a bottom surface of the substrate. The first and second transceivers optically communicate with each other through optical signals that permeate the substrate.