Removable Polyimide Dielectric Layer for Dense IC Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The semiconductor industry faces challenges in creating smaller and more integrated semiconductor packages due to limitations in packaging techniques, particularly in achieving high component density and stability during processing, especially with the need for advanced packaging methods like Package-on-Package (PoP) technology.
Innovation Solution
A method involving the formation of a semiconductor package with a dielectric layer that provides strength, durability, and flexibility, which can be efficiently removed in subsequent steps, including the use of a polyimide dielectric layer with an electron-attracting functional group for stability and a wet etching process for efficient removal, allowing for the formation of a front-side redistribution structure and efficient packaging of integrated circuit dies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dielectric layer is formed over an integrated circuit die to provide structural support and adhesion, then the stability and durability during processing are improved, but the complexity of subsequent manufacturing steps increases due to the need for selective removal
Solution Approach 1:
The dielectric layer uses a specific chemical composition (polyimide with electron-attracting functional groups) that enables selective removal through chemical etching. This parameter change in material composition allows the layer to provide structural stability during processing while being removable in subsequent steps through chemical reactions, resolving the contradiction between reliability and manufacturing complexity
Solution Approach 2:
The dielectric layer acts as an intermediary element that temporarily provides structural support and adhesion during processing, then is selectively removed to expose underlying structures. This intermediary function allows the layer to serve its protective role without permanently complicating the device structure, as it can be cleanly removed when no longer needed
2Quantity of substance
If advanced packaging techniques like Package-on-Package are used to achieve high component density, then the integration density is improved, but the difficulty of maintaining stability during processing increases
Solution Approach 1:
The dielectric layer is formed in advance over the integrated circuit die before packaging operations, providing preliminary structural support and adhesion. This preliminary action stabilizes the die structure before the complex Package-on-Package assembly process, enabling high component density while maintaining processing stability through the protective dielectric layer
3Strength
If a dielectric layer with high strength and durability is used to maintain robust adhesion during processing, then the reliability is improved, but the ease of removal in subsequent steps deteriorates
Solution Approach 1:
The dielectric layer's chemical composition is specifically designed with electron-attracting functional groups that create a dual-character material: strong mechanical adhesion to substrates and devices, but high chemical reactivity to specific etchants. This parameter change enables the layer to be both strong and easily removable, resolving the contradiction between adhesion strength and ease of removal
Solution Approach 2:
The chemical reactivity that would normally make a material difficult to remove is converted into a benefit through selective etching. The electron-attracting functional groups create chemical susceptibility that allows easy removal via wet etching, transforming what could be a harmful property (chemical reactivity) into a useful feature for manufacturing
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 approach enables the creation of stable and densely integrated semiconductor packages with improved manufacturing efficiency, maintaining robust adhesion and durability during processing, and facilitating efficient etching, thus addressing the need for smaller and more integrated semiconductor devices.
Implementation Method 1
a dielectric layer that provides strength, durability, and flexibility, which can be efficiently removed in subsequent steps, including the use of a polyimide dielectric layer with an electron-attracting functional group for stability
Implementation Method 2
a wet etching process for efficient removal
Data Source
AI summary
A method includes attaching an integrated circuit die adjacent to a first substrate, the integrated circuit die comprising: an active device in a second substrate; a pad adjacent to the second substrate; and a first dielectric layer adjacent to the second substrate, the first dielectric layer comprising a polyimide with an ester group; forming an encapsulant around the integrated circuit die; and removing the first dielectric layer.