Embedded Connection Member Structure for Stress-Resistant Circuit Boards

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Solution Overview

Problem

Existing semiconductor packages face limitations in reducing size and mechanical reliability due to silicon bridges, which are vulnerable to stress concentration and cracking, and require improved adhesion between connection members and build-up insulating layers.

Innovation Solution

A circuit board with a connection member embedded in a build-up insulating layer, comprising multiple insulating layers with different materials and stepped side surfaces, and a connection member made of organic materials with similar thermal expansion coefficients to minimize stress and improve adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a silicon bridge is used as a connection member, then electrical connection between semiconductor devices is achieved, but the size of the connection member cannot be reduced and mechanical reliability deteriorates due to stress concentration and cracking

Engineering Contradiction:

Improvemechanical reliabilityVSAvoidresistance to stress and cracking

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent changes the material parameter of the connection member from silicon to organic material, which has a coefficient of thermal expansion similar to the build-up insulating layer. This parameter change resolves the thermal expansion mismatch that causes stress concentration and cracking, thereby improving mechanical reliability while allowing size reduction.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structure where the connection member is formed of organic material that is integrated with the build-up insulating layer. This composite approach ensures compatible thermal and mechanical properties between the connection member and surrounding structures, preventing stress concentration and improving overall mechanical reliability.

Inventive Principle:

Principle #40Composite materials

2Reliability

If different insulating materials are used in the build-up insulating layer and connection member, then functional requirements are met, but adhesion between the connection member and build-up insulating layer deteriorates

Engineering Contradiction:

Improveadhesion strengthVSAvoidstress concentration at interface

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material composition parameter of the connection member to use organic material with thermal expansion coefficient matching the build-up insulating layer. This parameter alignment reduces thermal stress at the interface, preventing adhesion failure and improving bonding strength between different layers.

Inventive Principle:

Principle #35Parameter changes

3Volume of moving object

If the connection member size is reduced, then overall package size is reduced, but mechanical strength and reliability deteriorate

Engineering Contradiction:

Improvepackage sizeVSAvoidmechanical strength

Core Design Contradiction:

Volume of moving objectVSStrength

Solution Approach 1:

The patent changes the material parameter from silicon to organic material, which enables the connection member to be made smaller while maintaining or improving mechanical strength. The organic material's compatible thermal expansion properties prevent stress concentration, allowing size reduction without sacrificing mechanical 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

Enhances mechanical and electrical reliability by reducing stress, preventing cracking, and improving adhesion, while allowing for smaller connection members and more accurate semiconductor device mounting.

Implementation Method 1

a connection member made of organic materials with similar thermal expansion coefficients to minimize stress

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4597569A1Circuit board, and semiconductor package comprising same

Publication Date: 2025.08.06 LG INNOTEK CO LTD

Figure 1a
Figure 1b~1c
Figure 1d~1e

AI summary

A circuit board according to an embodiment includes a build-up insulating layer; a connection member embedded in the build-up insulating layer; and an insulating member disposed on one surface of the connection member, wherein the connection member includes: a first insulating layer; and a second insulating layer disposed on the first insulating layer, wherein the first insulating layer, the second insulating layer, and the insulating member includes different insulating materials, and wherein a side surface of the first insulating layer, a side surface of the second insulating layer, and a side surface of the insulating member have a step.