Semiconductor Package Bonding Layout to Prevent Copper Ion Leakage

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Solution Overview

Problem

During the manufacture of multi-chip semiconductor packages, voids at the bonding interface can lead to leakage defects due to copper ion migration caused by potential differences between adjacent bonding pads, resulting in reduced bonding quality.

Innovation Solution

The semiconductor package design includes dummy bonding pads in the peripheral regions without redistribution pads, preventing electrical signal transmission and thus eliminating potential differences between adjacent pads, which prevents copper ion migration and enhances bonding quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bonding pads are arranged in peripheral region for electrical connection, then electrical signals can be transmitted, but voids at bonding interface cause leakage defects due to copper ion migration

Engineering Contradiction:

Improvebonding qualityVSAvoidleakage defects

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies equipotentiality by configuring dummy bonding pads in the peripheral region to have the same electrical potential as adjacent bonding pads. This eliminates potential differences between neighboring pads, thereby preventing copper ion migration that occurs due to voltage gradients. The dummy pads act as potential equalizers, ensuring that even if voids exist at the bonding interface, no leakage current can flow because there is no driving potential difference.

Inventive Principle:

Principle #12Equipotentiality

Solution Approach 2:

The patent introduces dummy bonding pads as intermediary elements between functional bonding pads in the peripheral region. These dummy pads serve as mediating structures that intercept and equalize potential differences, preventing direct electrical interaction that would cause copper ion migration. The dummy pads act as a buffer zone, mediating the electrical environment to eliminate harmful potential gradients without affecting the functionality of primary bonding pads.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If dummy bonding pads are added in peripheral region, then potential differences are eliminated and leakage prevented, but device complexity increases

Engineering Contradiction:

Improvebonding qualityVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by implementing dummy bonding pads specifically in the peripheral region where bonding interface voids are most likely to occur, rather than uniformly across the entire device. This localized approach addresses the specific problem area (peripheral bonding interfaces) without unnecessarily complicating the central functional regions. The dummy pads are strategically placed only where needed to eliminate potential differences, maintaining simplicity in non-problematic areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent modifies the electrical parameters of the peripheral region by introducing dummy bonding pads that change the potential distribution. Instead of altering the fundamental bonding structure, the invention changes the electrical parameter (potential difference) locally in the peripheral region. This parameter-based solution eliminates leakage by adjusting voltage conditions rather than redesigning the entire bonding interface, thereby minimizing structural complexity while achieving reliability improvement.

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 design effectively prevents leakage defects by eliminating potential differences between adjacent bonding pads, thereby increasing the bonding quality and reliability of the semiconductor package.

Implementation Method 1

pad-to-pad direct bonding may be performed without using solder bumps

Methodology Applied

Scientific EffectDirect bonding: Diffusion Welding

Implementation Method 2

leakage defects may occur due to the migration of copper ions based on a potential difference between the power signal and the ground signal between adjacent bonding pads

Methodology Applied

Scientific EffectPotential difference: Electric Field

Data Source

PatentUS20250006676A1Semiconductor package and method of manufacturing the semiconductor package

Publication Date: 2025.01.02 SAMSUNG ELECTRONICS CO LTD

AI summary

A semiconductor package includes a first semiconductor chip including first bonding pads disposed in a first main region on a first surface of a first substrate, first dummy bonding pads disposed in a first peripheral region on the first surface of the first substrate, and a first passivation layer disposed on the first surface, and a second semiconductor chip on the first semiconductor chip and including a wiring layer on a third surface of a second substrate and including redistribution pads in a second main region, second bonding pads disposed on the redistribution pads, second dummy bonding pads disposed in a second peripheral region on the wiring layer, and a second passivation layer disposed on the wiring layer. The first bonding pads and the second bonding pads are directly bonded to each other. The first dummy bonding pads and the second dummy bonding pads are directly bonded to each other.