Protective Tape Modulus Ratio for Residue-Free Semiconductor Bumps
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Solution Overview
Problem
Conventional back grind tapes with a thermosetting resin layer can obstruct solder bonding and degrade connection properties during the semiconductor manufacturing process due to resin residue on bumps.
Innovation Solution
A protective tape with a specific composition including an adhesive layer, a thermoplastic resin layer, and a backing material film layer, where the modulus ratio of the adhesive layer to the thermoplastic resin layer's shear storage modulus is 0.01 or less at application temperature, ensuring the adhesive layer remains and other layers are removed, thereby suppressing resin residue on bumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a thermosetting resin layer is left on the wafer during back grinding, then the wafer surface is protected during grinding, but resin residue remains on bumps and obstructs solder bonding
Solution Approach 1:
The protective tape is divided into multiple functional layers: a thermosetting resin layer for protection during grinding, a thermoplastic resin layer that allows selective removal, and an adhesive layer for bonding. This segmentation enables the thermosetting resin to provide protection while the thermoplastic layer can be removed to prevent residue issues.
Solution Approach 2:
The invention extracts the problematic thermosetting resin layer from direct contact with the bumps by placing it behind a removable thermoplastic resin layer. The thermoplastic layer acts as a sacrificial barrier that can be completely removed, taking the potential residue problem away while the thermosetting layer continues to provide structural protection.
2Strength
If the adhesive layer has high shear storage modulus, then strong adhesion is achieved, but resin residue obstructs solder bonding
Solution Approach 1:
Different layers are assigned different mechanical properties suited to their specific functions: the adhesive layer has high shear storage modulus for strong bonding to the substrate, while the thermoplastic resin layer has lower shear storage modulus enabling its removal without leaving residue. Each layer's local properties are optimized for its particular role in the system.
3Device complexity
If a single-layer protective tape is used, then the structure is simple, but it cannot provide both protection and prevent resin residue
Solution Approach 1:
The protective tape uses a composite structure combining thermosetting resin (for rigid protection during grinding), thermoplastic resin (for removable protection preventing residue), and adhesive materials (for bonding). This composite approach integrates multiple functions—protection, residue prevention, and adhesion—into a single multi-layer system, achieving reliable connection properties while maintaining practical structural complexity.
Data Source
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AI summary
A protective tape and a method for manufacturing a semiconductor device using the same capable of achieving excellent connection properties. The protective tape includes an adhesive layer (11), a thermoplastic resin layer (12) and a backing material film (13) in that order; a modulus ratio of a shear storage modulus of the adhesive layer (11) to a shear storage modulus of the thermoplastic resin layer (12) at an application temperature at which the protective tape is applied is 0.01 or less. This suppresses resin residue on bumps thereby achieving excellent connection properties.