Interposer Conductive Wires via Nanoparticle Ink Sintering

Solution Overview

Problem

The challenge in forming reliable interconnections between integrated circuits and other components is the complexity of metal deposition into narrow vias, which can result in metal discontinuities and voids, impairing electrical conductivity and reliability.

Innovation Solution

The process involves manufacturing vias as free-standing posts using nanoparticle inks, which are then deposited and sintered to form conductive wires, and these wires are coated with a conductive layer to enhance conductivity, with the option of using magnetic fields to maintain wire shape and orientation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If metal deposition is performed into narrow vias to reduce lateral area, then the lateral area is reduced, but metal discontinuities and voids occur which impair electrical conductivity and reliability

Engineering Contradiction:

Improvelateral areaVSAvoidelectrical conductivity and reliability

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The via posts are formed as free-standing structures on a sacrificial substrate before being inserted into the final support. This preliminary formation allows for better control of the conductive material deposition process, ensuring complete filling without discontinuities or voids that would occur with direct deposition into narrow holes.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A sacrificial substrate is introduced as an intermediary element during the via formation process. The via posts are initially formed on this temporary substrate, which facilitates controlled metal deposition and subsequent insertion into the final support structure, eliminating the problems of direct narrow via filling.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Area of stationary object

If via holes are made narrow to reduce lateral area, then the lateral area is reduced, but metal deposition becomes complicated resulting in discontinuities and voids

Engineering Contradiction:

Improvelateral areaVSAvoidmetal deposition process

Core Design Contradiction:

Area of stationary objectVSEase of manufacture

Solution Approach 1:

The via posts are formed as free-standing structures on a sacrificial substrate before being inserted into the final support. This preliminary formation allows for better control of the conductive material deposition process, ensuring complete filling without discontinuities or voids that would occur with direct deposition into narrow holes.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of forming vias by directly creating holes and filling them with metal (the conventional approach), the invention inverts the process by first forming complete via posts as free-standing structures on a sacrificial substrate, then inserting them into the final support. This reversal simplifies the metal deposition process.

Inventive Principle:

Principle #13The other way round (Inversion)

3Device complexity

If conventional metal deposition is used to form vias, then the process is simpler, but metal discontinuities and voids occur which impair electrical conductivity

Engineering Contradiction:

Improvefabrication processVSAvoidelectrical conductivity

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The via posts are formed as free-standing structures on a sacrificial substrate before being inserted into the final support. This preliminary formation allows for better control of the conductive material deposition process, ensuring complete filling without discontinuities or voids that would occur with direct deposition into narrow holes.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A sacrificial substrate is introduced as an intermediary element during the via formation process. The via posts are initially formed on this temporary substrate, which facilitates controlled metal deposition and subsequent insertion into the final support structure, eliminating the problems of direct narrow via filling.

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 approach results in thin, strong, conductive wires with high aspect ratios and improved electrical conductivity, reducing porosity and enhancing the reliability of interconnections, thereby addressing the issues of metal discontinuities and voids in traditional deposition methods.

Implementation Method 1

which are then deposited and sintered to form conductive wires

Methodology Applied

Scientific EffectSintering: Sintering

Implementation Method 2

with the option of using magnetic fields to maintain wire shape and orientation

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentUS10440822B2Interposers with electrically conductive features having different porosities

Publication Date: 2019.10.08 ADEIA SEMICON TECH LLC

AI summary

Interposer circuitry (130) is formed on a possibly sacrificial substrate (210) from a porous core (130′) covered by a conductive coating (130″) which increases electrical conductance. The core is printed from nanoparticle ink. Then a support (120S) is formed, e.g. by molding, to mechanically stabilize the circuitry. A magnetic field can be used to stabilize the circuitry while the circuitry or the support are being formed. Other features are also provided.