Wafer-Processing Tape with Segmented Adhesive Zones
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Solution Overview
Problem
Conventional wafer-processing tapes face challenges in preventing adhesive residue on the ring frame during the dicing process, requiring complex surface modifications and increased production costs due to difficulties in controlling the peeling force between the adhesive layer and the removable adhesive layer.
Innovation Solution
A wafer-processing tape with distinct areas of different peeling forces between the adhesive layer, removable adhesive layer, and base film, where the adhesive layer is transferred to the chip side during pickup and the removable adhesive layer remains on the base film side during peeling, preventing adhesive transfer to the ring frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the adhesive layer is designed with high adhesive strength to prevent wafer peeling during dicing, then the wafer remains securely fixed, but the adhesive transfers to the ring frame during tape peeling, causing adhesive residue
Solution Approach 1:
The tape structure is segmented into distinct functional zones: a wafer adhesion area with high adhesive strength for securing the wafer during dicing, and a ring frame contact area with low adhesive strength or release properties to prevent adhesive transfer during tape removal. This spatial segmentation allows the tape to exhibit different adhesive characteristics in different regions, resolving the contradiction between strong wafer fixation and clean tape release.
Solution Approach 2:
The adhesive layer is designed with locally differentiated properties: high adhesive strength in the wafer mounting region and low adhesive strength or release coating in the ring frame contact region. This local quality variation enables the tape to maintain strong bonding where needed while preventing adhesive residue where not needed, without requiring complex global modifications to the adhesive formulation.
2Ease of operation
If the peeling force between the adhesive layer and removable adhesive layer is reduced to enable easy chip pickup, then the chip can be easily separated, but the adhesive layer becomes too weak to maintain wafer fixation during dicing
Solution Approach 1:
The tape structure incorporates a removable adhesive layer with differentiated bonding characteristics: strong bonding to the wafer surface to ensure secure fixation during dicing, and weak bonding to the base film to enable easy chip pickup. This layered segmentation creates distinct failure planes that allow controlled separation during the pickup process while maintaining integrity during dicing.
Solution Approach 2:
The removable adhesive layer is pre-designed with selective bonding properties before the dicing process begins. The layer is formulated to bond strongly to the wafer surface under dicing conditions but to release easily from the base film during pickup, anticipating the different operational requirements of each process stage and preparing the adhesive system in advance to meet both demands.
3Ease of manufacture
If conventional tapes use uniform adhesive properties across the entire tape surface, then the manufacturing process is simple, but the tape cannot selectively adhere to the wafer while preventing adhesive transfer to the ring frame
Solution Approach 1:
The tape is manufactured with segmented adhesive functionality through a laminated structure comprising a base film, a removable adhesive layer with uniform properties applied across the surface, and an adhesive layer with spatially varying properties. This segmentation approach maintains manufacturing simplicity by using standard lamination processes while achieving precise adhesive transfer control through the inherent functional differentiation of the layered structure.
Solution Approach 2:
The tape employs a composite structure combining multiple layers with different adhesive characteristics: a base film providing structural support, a removable adhesive layer with uniform bonding properties for consistent wafer adhesion, and an adhesive layer with locally differentiated properties for controlled release. This composite material approach enables precise adhesive transfer control while maintaining compatibility with conventional manufacturing processes.
Data Source
AI summary
A wafer-processing tape, which has an adhesive layer and a removable adhesive layer formed on a surface of a base film, and which has an area where B>A, and an area where A>B, in which a peeling force between the base film and the adhesive layer is designated as A, and peeling forces between a target to be bonded and the adhesive layer and between a target to be bonded and the removable adhesive layer are designated as B, wherein the adhesive layer is transferred onto the chip side during pickup in the area where B>A, and the removable adhesive layer is not transferred onto the target to be bonded in the area where A>B during peeling off the tape.