Fan-Out Semiconductor Package With Optical Debonding Interposer
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Solution Overview
Problem
Conventional fan-out semiconductor packages face inefficiencies in the manufacturing process due to residual separation layer remnants, which require etching and can lead to plump defects and contact failures, especially when using high-cost silicon interposers, and the process is inefficient and prone to defects during the separation of the interposer from the carrier.
Innovation Solution
A semiconductor package design featuring a non-silicon interposer with fine-pitched wiring and a photo imageable dielectric separation layer that is partially decomposed by light, allowing for optical de-bonding from the carrier without mechanical stress, eliminating the need for additional separation members and etching processes, and incorporating recesses on the interposer surface to enhance the under-fill resin contact area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a separation layer is used to bond the interposer to the carrier and then decompose it for separation, then the interposer can be separated from the carrier, but residuals of the separation layer remain on the interposer requiring additional etching processes
Solution Approach 1:
The patent extracts the separation layer completely from the interposer surface during the separation process. The separation layer is designed to be fully removable without leaving residuals, eliminating the need for subsequent etching processes to remove remaining separation layer material.
Solution Approach 2:
The patent replaces mechanical separation methods with chemical decomposition of the separation layer. By using a photoimageable dielectric material that decomposes upon light exposure, the separation process becomes more controlled and complete, avoiding mechanical stress that could leave residuals.
2Ease of operation
If the interposer is separated from the carrier by decomposing the separation layer, then separation is achieved, but the process efficiency is significantly reduced due to required etching processes
Solution Approach 1:
The separation layer is completely extracted during separation, eliminating the need for time-consuming etching processes to remove residuals. This complete extraction approach streamlines the manufacturing process and improves overall productivity.
Solution Approach 2:
The separation process is designed to be continuous and complete, with the separation layer decomposing fully during separation. This eliminates the need for additional etching steps, maintaining continuous productive action throughout the manufacturing process.
3Ease of manufacture
If a single interposer is adhered to the whole surface of a panel type carrier and then separated into trim panels, then the interposer can be divided into usable pieces, but the separation layer is partially broken and torn causing plump defects
Solution Approach 1:
The patent replaces mechanical cutting and separation methods with photochemical decomposition of the separation layer. This substitution eliminates mechanical stress that causes the separation layer to tear and creates plump defects, ensuring clean separation into trim panels.
Solution Approach 2:
The patent changes the state of the separation layer from solid adhesive to decomposed material through light exposure. This parameter change allows the separation layer to break down cleanly without mechanical stress, preventing tears and plump defects during trim panel separation.
4Ease of manufacture
If the separation layer is broken and torn during trim process, then trim panels are separated, but wirings on the interposer are occasionally separated from the separation layer causing contact failures
Solution Approach 1:
The patent replaces mechanical separation with photochemical decomposition, eliminating the tearing and breaking of the separation layer that causes wirings to detach. This ensures reliable electrical connections are maintained throughout the trim process.
Solution Approach 2:
By changing the separation layer's state through light-induced decomposition rather than mechanical force, the patent prevents wiring detachment. The controlled chemical breakdown maintains wiring integrity and prevents contact failures.
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 improves the flatness and reliability of the interposer, reduces contact failures, and enhances the combining force between the semiconductor package and the main board, while eliminating the need for additional etching processes and mechanical de-bonding, thus improving the overall manufacturing efficiency and package performance.
Implementation Method 1
a photo imageable dielectric separation layer that is partially decomposed by light
Data Source
AI summary
A semiconductor package includes an interposer having a separation layer on a rear surface of which a plurality of first recesses is arranged. A plurality of wiring structures is stacked on the separation layer alternately with a plurality of insulation interlayers. A plurality of semiconductor devices is arranged, side by side, on the interposer side and connected to a plurality of the wiring structures. A plurality of contact terminals on the rear surface of the separation layer is connected to the plurality of the wiring structures through the separation layer. A flatness deterioration of the interposer is minimized and the contact surface between the interposer and under fill resin is enlarged.