Semiconductor Spacer Composition for Dense Stacked PCB Assemblies

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Solution Overview

Problem

Conventional spacers in miniaturized electronic devices face limitations due to thermal expansion mismatches and difficulties in patterning fine features, which hinder the scalability and performance of stacked electronic devices.

Innovation Solution

The use of semiconductor device spacers made from polymer-based dielectric materials with spherical ceramic fillers, featuring vias for electrical interconnections, addresses the thermal expansion issues and enables precise patterning for improved electrical connectivity and structural support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional molding compound materials are used for spacers, then the spacers provide physical separation between device components, but coefficient of thermal expansion mismatch occurs causing warpage and requiring larger solder bumps with greater spacing

Engineering Contradiction:

Improvethermal expansion compatibilityVSAvoiddevice scaling capability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent changes the material parameters of the spacer by using a polymer-based dielectric material with spherical ceramic fillers instead of conventional molding compound. This material composition change enables the spacer to achieve coefficient of thermal expansion values between 50 and 150 ppm/°C, matching the device components and eliminating warpage while allowing finer feature patterning and improved device scaling

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite material structure consisting of a polymer-based dielectric matrix reinforced with spherical ceramic fillers. This composite approach combines the advantages of both materials: the polymer provides flexibility and processability while the ceramic fillers provide thermal stability and matched CTE, resolving the thermal expansion mismatch problem

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If conventional molding compound materials are used for spacers, then the spacers can be formed with current manufacturing processes, but fine features (less than 50 μm) cannot be patterned due to material properties and mechanical process limitations

Engineering Contradiction:

Improvefeature patterning capabilityVSAvoidpatterning process complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the material parameters of the spacer material to enable fine feature patterning. The polymer-based dielectric material with spherical ceramic fillers has improved mechanical properties and etch selectivity that allow mechanical structuring processes to pattern features smaller than 50 μm, achieving the required manufacturing precision for scaled devices

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by using spherical ceramic fillers distributed within the polymer matrix, which provide localized structural support and etch resistance in critical areas. This enables the material to be selectively patterned with fine features while maintaining overall structural integrity during manufacturing

Inventive Principle:

Principle #3Local quality

3Reliability

If larger solder bumps with greater spacing are used to mitigate warpage, then thermal expansion mismatch is addressed, but the device footprint increases and connectivity density decreases

Engineering Contradiction:

Improvewarpage mitigationVSAvoiddevice footprint

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent changes the fundamental parameter of spacer material composition to match the coefficient of thermal expansion of device components. This eliminates the root cause of warpage, allowing the use of smaller solder bumps with tighter spacing and reducing the overall device footprint while maintaining reliability

Inventive Principle:

Principle #35Parameter changes

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 enhances the scalability and performance of stacked electronic devices by reducing thermal expansion mismatches and allowing for finer features, leading to increased bandwidth and efficiency.

Implementation Method 1

coefficient of thermal expansion (CTE) mismatch may occur between the device components and adjacent spacers

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a frame material including a polymer-based dielectric material with spherical ceramic fillers

Methodology Applied

Scientific EffectComposite materials: Composite Materials

Data Source

PatentUS11742330B2High connectivity device stacking

Publication Date: 2023.08.29 APPLIED MATERIALS INC

AI summary

The present disclosure generally relates to stacked miniaturized electronic devices and methods of forming the same. More specifically, embodiments described herein relate to semiconductor device spacers and methods of forming the same. The semiconductor device spacers described herein may be utilized to form stacked semiconductor package assemblies, stacked PCB assemblies, and the like.