Insulating Layer Stack for Smoother Metal Bump Interconnects
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Solution Overview
Problem
The increase in surface roughness of metal layers in electronic devices due to increased process steps affects the electrical properties, necessitating a solution to improve the design and manufacturing process.
Innovation Solution
The implementation of multiple insulating layers to protect and stabilize metal bumps and layers, including a first insulating layer with a second insulating layer covering part of the first metal bump, a third insulating layer exposing part of a second metal bump, and a fourth insulating layer extending to contact the second metal bump, thereby reducing surface roughness and enhancing electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple process steps are increased to achieve higher integration and more functions, then the functionality and complexity of the electronic device are improved, but the surface roughness of the metal layer increases and electrical properties deteriorate
Solution Approach 1:
The patent divides the protective structure into multiple insulating layers (first insulating layer, second insulating layer, third insulating layer) with different functions. Each layer is positioned at different stages to protect metal bumps and layers, allowing the system to maintain electrical properties while accommodating complex multi-functional designs.
Solution Approach 2:
The insulating layers act as intermediary protective elements between the metal bumps/layers and the external environment or subsequent processing steps. These intermediary layers prevent direct exposure and damage, maintaining surface smoothness and electrical conductivity despite increased process complexity.
2Adaptability or versatility
If more chips and I/O circuits are integrated into a single device, then the functionality is improved, but the surface roughness of metal layers increases affecting electrical properties
Solution Approach 1:
The protective structure is segmented into multiple insulating layers positioned at different locations and stages. The first insulating layer protects underlying metal layers, while the second and third insulating layers protect metal bumps at different elevations, ensuring electrical reliability across densely integrated I/O circuits.
Solution Approach 2:
The patent extends protection into the vertical dimension by stacking multiple insulating layers at different heights and positions. This multi-layer approach protects metal structures in three-dimensional space, maintaining electrical properties despite high integration density requiring complex routing and stacking.
3Adaptability or versatility
If the quantity of I/O is increased to meet requirements, then the adaptability is improved, but the surface roughness increases and electrical properties worsen
Solution Approach 1:
The insulating structure is divided into multiple layers that can be selectively applied to different I/O regions. This segmentation allows protection of individual metal bumps and layers regardless of the total number of I/Os, maintaining surface quality even as I/O quantity increases.
Data Source
AI summary
An electronic device includes: a first insulating layer; a first metal bump disposed on the first insulating layer; a second insulating layer disposed on the first metal bump; a metal layer, wherein the first insulating layer is disposed between the second insulating layer and the metal layer; a second metal bump disposed between the metal layer and the first insulating layer, wherein the second metal bump electrically connects to the first metal bump; a third insulating layer disposed between the second metal bump and the first insulating layer, wherein the third insulating layer includes an opening exposing a portion of the second metal bump; and a fourth insulating layer disposed between the third insulating layer and the first insulating layer, wherein a portion of the fourth insulating layer extends and is disposed in the opening to contact the second metal bump.