Dicing Sheet Adhesive Layer for TSV Residue Control
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Solution Overview
Problem
Conventional dicing sheets used for semiconductor wafers with through-silicon via (TSV) electrodes often result in residue contamination and chipping due to the pressure sensitive adhesive layer embedding into the TSVs, leading to reliability issues and incomplete removal of adhesive residues.
Innovation Solution
A dicing sheet with a pressure sensitive adhesive layer having energy ray curable double bonds and a specific elasticity profile, which prevents the adhesive from following into the TSVs and allows for controlled curing, thereby avoiding residue and chipping during the dicing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure sensitive adhesive layer is pressed against the through-silicon via to embed the electrode, then the semiconductor wafer is fixed to the dicing sheet, but the adhesive layer embeds into the through-silicon via causing residue contamination on the chip surface
Solution Approach 1:
The patent changes the physical-chemical parameters of the adhesive layer by introducing energy ray curable components and controlling storage elasticity to prevent embedding while maintaining fixation capability
Solution Approach 2:
The adhesive layer is formulated as a composite material containing both energy ray curable components and substances providing specific storage elasticity, combining the benefits of controlled adhesion and resistance to embedding
2Manufacturing precision
If the elasticity of the pressure sensitive adhesive layer is reduced to embed the through-silicon via, then the electrode embedding is achieved, but chip chipping occurs easily due to vibration during dicing
Solution Approach 1:
The patent optimizes the storage elasticity parameter of the adhesive layer to achieve a balance between embedding capability and vibration resistance, preventing both excessive embedding and chip chipping
3Ease of operation
If the pressure sensitive adhesive layer is used to fix the semiconductor wafer, then the wafer is held in position during dicing, but adhesive residue remains between the through-silicon vias after dicing
Solution Approach 1:
The adhesive layer undergoes a phase transition from a soft, deformable state during lamination to a cured, rigid state after energy ray irradiation, preventing residue formation while maintaining ease of wafer handling
Solution Approach 2:
The adhesive layer is pre-formulated with energy ray curable components that enable subsequent curing to eliminate residue, preparing the material in advance to solve the residue problem
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 solution effectively prevents adhesive residue between TSVs, enhances dicing properties, and ensures chip integrity by regulating adhesive force and preventing water intrusion, allowing for easier chip pickup without breaking.
Implementation Method 1
a storage elasticity G′ at 23° C. of the pressure sensitive adhesive layer before curing is larger than 4 times of a storage elasticity at 23° C. of the intermediate layer
Implementation Method 2
the pressure sensitive adhesive layer comprises a compound having an energy ray curable double bond in a molecule
Data Source
AI summary
A dicing sheet includes a base, an intermediate layer on one face of the base, and an pressure sensitive adhesive layer provided on the intermediate layer and having the thickness of 8 to 30 μm. The pressure sensitive adhesive layer includes a compound having an energy ray curable double bond in a molecule, and a storage elasticity G′ at 23° C. of the pressure sensitive adhesive layer before curing is larger than 4 times of a storage elasticity at 23° C. of the intermediate layer. When the dicing sheet is laminated via the adhesive sheet on a wafer formed with a cylinder shape electrodes having a height of 15 μm and a diameter of 15 μm at a pitch of 40 μm having 3 rows 3 columns in equal spacing, at a center of the electrode of the cylinder shape electrodes formed in 3 rows 3 columns, the pressure sensitive adhesive layer does not contact at a part of a height of 7.5 μm or less of the electrode.