Asymmetric Adhesion Regions for IC Package STIM Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional integrated circuit (IC) packages face challenges with heat management due to bleedout and voiding of solder thermal interface materials (STIMs), which compromise thermal performance and require large keep-out zones, limiting device density and reliability.

Innovation Solution

Incorporating asymmetric adhesion material regions on the lid of IC packages that guide the melted STIM towards specific areas, reducing bleedout and voiding, and enabling the use of STIMs instead of polymer-based thermal interface materials, thus enhancing thermal conductivity and package density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If symmetric adhesion material regions are used on the lid, then the STIM distributes evenly during assembly, but the STIM experiences bleedout and voiding that compromise thermal performance

Engineering Contradiction:

ImproveSTIM distribution uniformityVSAvoidthermal performance

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies asymmetry by configuring the adhesion material region on the lid with an asymmetric footprint relative to the die. The adhesion material extends beyond the die footprint on specific sides (first and second sides) but not on other sides (third and fourth sides), creating a non-uniform distribution pattern that prevents STIM bleedout and voiding while maintaining reliable thermal performance.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent implements local quality by providing different extension distances of the adhesion material beyond the die footprint on different sides. The adhesion material extends by a first distance on the first side and a second distance on the second side, where these distances differ, creating localized variations in adhesion strength that control STIM flow and distribution during the attachment process.

Inventive Principle:

Principle #3Local quality

2Reliability

If large keep-out zones are used to prevent STIM bleedout, then thermal performance is maintained, but device density is reduced

Engineering Contradiction:

Improvethermal performanceVSAvoiddevice density

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The asymmetric adhesion material configuration eliminates the need for large symmetric keep-out zones by providing targeted adhesion control only where needed. The adhesion material extends beyond the die footprint selectively on specific sides, preventing STIM bleedout in those areas while allowing closer component placement on other sides, thereby increasing device density without compromising thermal performance.

Inventive Principle:

Principle #4Asymmetry

3Ease of manufacture

If polymer-based thermal interface materials are used, then ease of manufacture is improved, but thermal conductivity is reduced

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidthermal conductivity

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The patent changes the material parameter from polymer-based thermal interface material to solder thermal interface material (STIM). This material substitution significantly improves thermal conductivity while the asymmetric adhesion material configuration ensures the STIM remains controllable during assembly, preventing bleedout and voiding that would otherwise compromise manufacturing 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

The asymmetric adhesion material regions effectively control STIM distribution, reducing keep-out zones and ensuring reliable thermal performance, allowing for more densely packed and thermally efficient IC packages.

Implementation Method 1

a solder thermal interface material (STIM) in contact with the first adhesion material region and the second adhesion material region

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the lid includes a second adhesion material region, asymmetric with respect to the die, in contact with the STIM

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS11682605B2Integrated circuit packages with asymmetric adhesion material regions

Publication Date: 2023.06.20 SK HYNIX NAND PRODUCT SOLUTIONS CORP

AI summary

Disclosed herein are integrated circuit (IC) packages with asymmetric adhesion material regions, as well as related methods and devices. For example, in some embodiments, an IC package may include a solder thermal interface material (STIM) between a die of the IC package and a lid of the IC package. The lid of the IC package may include an adhesion material region, in contact with the STIM, that is asymmetric with respect to the die.