Semiconductor Device Wiring Stability via Tapered Mask Sandblasting

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Solution Overview

Problem

Existing semiconductor devices face a high risk of wiring member disconnection due to the formation of tapered through holes with steep sidewalls, which are created using sandblasting techniques, leading to unstable connections.

Innovation Solution

A method involving the use of a mask with a first opening and a second opening that tapers inwardly to form a slope on the substrate, allowing for a sandblast process that creates a through hole with a moderate slope, enabling the formation of wiring members that reduce the risk of disconnection by providing a more stable surface for electrical connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a sandblasting technique is used to form a through hole in the substrate, then the through hole can be formed efficiently, but the sidewall becomes steep which increases the risk of wiring member disconnection

Engineering Contradiction:

Improvethrough hole formation efficiencyVSAvoidwiring member connection stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The mask opening is divided into two distinct parts: a first opening at the upper surface and a second opening at the lower surface of the upper substrate. This segmentation allows the sandblasting process to create a through hole with a controlled moderate slope rather than a steep sidewall, thereby improving wiring member connection stability while maintaining formation efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The mask with the specific two-part opening structure is prepared in advance before the sandblasting process. This preliminary action of designing the mask geometry ensures that when sandblasting occurs, the wiring members will be deposited on a moderately sloped surface rather than a steep one, preventing disconnection issues before they can occur.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a mask with a first opening and a second opening is used to form a moderate slope, then wiring member disconnection risk is reduced, but the mask structure becomes more complex

Engineering Contradiction:

Improvewiring member connection stabilityVSAvoidmask structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The mask combines the first opening and second opening into a single integrated structure. This merging allows the complex function of creating a moderate slope to be achieved through one mask component rather than requiring multiple separate processing steps or components, thus managing overall device complexity while improving reliability.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the second opening has a smaller area than the first opening, then a moderate slope is formed improving connection stability, but the area for sandblast process is reduced

Engineering Contradiction:

Improvewiring member connection stabilityVSAvoidsandblast process area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The mask opening has different areas at different locations: the first opening at the upper surface has a larger area to allow sufficient sandblast access, while the second opening at the lower surface has a smaller area to create the moderate slope geometry. This local variation in area optimizes both the sandblast process effectiveness and the resulting connection stability.

Inventive Principle:

Principle #3Local quality

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 method effectively reduces the risk of wiring member disconnection by forming a semiconductor device with a moderate slope, allowing for stable electrical connections without increasing process steps or costs, and enabling the creation of both sidewalls and slopes simultaneously.

Implementation Method 1

carrying out a sandblast process on the upper substrate exposed to an outside via the first opening and the second opening

Methodology Applied

Scientific EffectSandblasting: Abrasion

Data Source

PatentUS11148937B2Method of manufacturing semiconductor device and semiconductor device

Publication Date: 2021.10.19 MITSUBISHI ELECTRIC CORP

AI summary

A method includes attaching an upper substrate to an upper surface of a sensor substrate, forming, on an upper surface of the upper substrate, a mask providing a first opening and a second opening communicating with the first opening, the second opening having a width that decreases with increase in a distance from the first opening, carrying out a sandblast process on the upper substrate exposed to an outside via the first opening and the second opening, allowing the sensor substrate to be exposed to the outside immediately below the first opening, and forming a slope on the upper substrate immediately below the second opening, and forming a first wiring member in contact with the exposed sensor substrate and a second wiring member being in contact with the slope and continuing to the first wiring member.