Semiconductor Device With Variable Trace Width For Crack Resistance

Solution Overview

Problem

In semiconductor devices with stacked memory chips, cracks can occur in the bonding layer due to thermal stress, which complicates impedance control for high-speed signals like PCIe, limiting the trace width and affecting electrical performance.

Innovation Solution

A semiconductor device design featuring a multilayer wiring substrate with a bonding layer and trace width variations, including a thicker trace width portion to reinforce the substrate and prevent crack propagation, while maintaining impedance control for high-speed signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the trace width is increased to reduce crack influence, then reliability improves, but impedance control for high-speed signals deteriorates

Engineering Contradiction:

Improvecrack resistanceVSAvoidimpedance control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The trace width is varied locally along its length, being wider at portions where cracks are likely to occur and narrower at other portions. This local variation allows the trace to have enhanced crack resistance at critical locations while maintaining proper impedance control overall, resolving the contradiction between reliability and manufacturing precision.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If the trace width is decreased for impedance control, then electrical performance improves, but crack resistance deteriorates

Engineering Contradiction:

Improveimpedance controlVSAvoidcrack resistance

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The trace width is varied locally along its length, being wider at portions where cracks are likely to occur and narrower at other portions. This local variation allows the trace to have enhanced crack resistance at critical locations while maintaining proper impedance control overall, resolving the contradiction between reliability and manufacturing precision.

Inventive Principle:

Principle #3Local quality

3Reliability

If the trace width is made variable, then crack resistance improves, but device complexity increases

Engineering Contradiction:

Improvecrack resistanceVSAvoidtrace structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The trace is segmented into multiple portions with different width characteristics - a first trace width portion and a second trace width portion. This segmentation approach allows the trace to achieve improved crack resistance through width variation while keeping the structural complexity manageable by dividing the trace into distinct functional segments rather than using continuous complex variations.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11527469B2Semiconductor device

Publication Date: 2022.12.13 KIOXIA CORP

AI summary

A semiconductor device includes: a multilayer wiring substrate including a plurality of wiring layers; a first semiconductor chip disposed on the wiring substrate; and a bonding layer bonding the first semiconductor chip to the wiring substrate. A trace formed on the wiring substrate includes a first trace width portion and a second trace width portion, a width of the first trace width portion being greater than the second trace width portion.