Fan-Out Packaging Strain Adjustment Layer After Laser Debonding
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Solution Overview
Problem
Conventional fan-out type packaging structures face challenges with warpage issues after the laser debonding step, which affect fabrication yield rates and require additional steps and materials for warpage prevention.
Innovation Solution
Incorporating a strain adjustment layer made of a polymer material with at least 95% laser absorbance, which is partially embedded with chips and surrounds the encapsulation layer, replacing the need for a back protection layer and laser-debond film, thereby preventing warpage and simplifying the fabrication process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a back protection layer and laser-debond film are used in conventional fan-out packaging, then warpage prevention is attempted, but the process complexity increases and fabrication yield rates decrease due to severe warpage issues
Solution Approach 1:
The patent removes the separate back protection layer and laser-debond film from the conventional structure, extracting the warpage prevention function into the encapsulation layer itself. This simplifies the structure by eliminating redundant layers while maintaining or improving warpage control through the integrated design.
Solution Approach 2:
The patent merges the warpage prevention function with the encapsulation layer by configuring it with specific material properties (modulus of elasticity between 1-10 GPa) and structural features (thickness 50-200 μm). This integration combines multiple functions into a single layer, reducing overall process complexity.
2Reliability
If a back protection layer is adhered to prevent warpage after laser debonding, then some warpage is reduced, but additional adhering steps are required which consume time and reduce productivity
Solution Approach 1:
The patent implements warpage prevention in advance during the encapsulation process rather than as a corrective step after laser debonding. The encapsulation layer is designed with specific mechanical properties beforehand to inherently resist warpage, eliminating the need for subsequent adhering operations and improving productivity.
Solution Approach 2:
The encapsulation layer serves dual functions: protecting the chips and inherently preventing warpage through its material properties. This self-service capability eliminates the need for separate warpage prevention layers or additional processing steps, thereby improving fabrication efficiency.
3Strength
If multiple layers (back protection layer, laser-debond film, encapsulation layer) are used, then chip protection is achieved, but the number of fabrication steps increases
Solution Approach 1:
The patent extracts and removes the separate back protection layer and laser-debond film from the multi-layer structure, simplifying the manufacturing process while maintaining chip protection through the optimized encapsulation layer design.
Solution Approach 2:
The encapsulation layer is designed to perform multiple functions simultaneously: mechanical protection of chips, structural support, and warpage prevention through its specific modulus of elasticity range. This multi-functionality reduces the need for separate specialized layers.
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 strain adjustment layer effectively reduces warpage, improves fabrication yield rates, and saves time and costs by omitting the need for additional adhering steps, with the ability to adjust thickness based on projected warpage.
Implementation Method 1
The strain adjustment layer is made of a polymer material and has at least 95% laser absorbance
Data Source
AI summary
A fan-out type packaging structure includes a strain adjustment layer, a plurality of chips, an encapsulation layer, a redistribution layer, and a plurality of solder balls. The strain adjustment layer is made of a polymer material and has at least 95% laser absorbance. The plurality of chips are partially embedded in the strain adjustment layer and are spaced apart from each other. The encapsulation layer surrounds the chips and is connected to the strain adjustment layer. The redistribution layer covers the encapsulation layer and the chips. The plurality of solder balls are disposed on the redistribution layer and are spaced apart from each other.