Encapsulation Sheet Cutting for OLED Substrate Crack Prevention
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Solution Overview
Problem
In organic light-emitting display apparatus manufacturing, size discrepancies between substrates and encapsulation sheets can lead to stress concentration and cracking during the cutting process due to uneven support, resulting in unstable product production.
Innovation Solution
A method involving the preparation of a substrate with a display unit and peripheral parts, forming a cutting line on the encapsulation sheet to match the substrate size, adhering the sheets together, removing peripheral parts, and cutting the encapsulation sheet along the formed line to prevent step height generation and reduce cracking, using an encapsulation sheet with an insulating base film and metal wirings for conductive paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the encapsulation sheet size is made smaller than the substrate size, then the encapsulation sheet cannot provide adequate support during cutting, but increasing the encapsulation sheet size increases material cost and device complexity
Solution Approach 1:
The patent applies preliminary action by forming a cutting line on the encapsulation sheet before the cutting process. This pre-formed line guides the cutting tool and ensures that the cut follows the exact boundary between the display unit and peripheral parts, preventing deviation that could cause cracking or support issues. The cutting line is created through selective removal of metal wirings and partial punching of the base film at the boundary location.
Solution Approach 2:
The patent segments the encapsulation sheet structure by distinguishing between the base film and metal wirings, applying different treatments to each at the cutting line. The metal wirings are completely removed while the base film is partially punched, creating a structured separation that maintains support integrity during cutting while enabling clean separation afterward.
2Productivity
If the cutting process is performed without proper support from the encapsulation sheet, then cutting speed can be increased, but cracks are generated in the substrate due to stress concentration
Solution Approach 1:
The patent applies beforehand cushioning by ensuring the encapsulation sheet fully covers and supports the substrate periphery before the cutting process begins. The encapsulation sheet acts as a cushioning support layer that distributes cutting stresses uniformly across the substrate, preventing stress concentration at the edges. This pre-established support system allows for faster cutting speeds without generating cracks.
3Reliability
If the peripheral parts of the substrate are removed after bonding, then the display unit is properly isolated, but step heights are generated that lead to cracking
Solution Approach 1:
The patent applies preliminary action by forming the cutting line on the encapsulation sheet before removing the peripheral parts of the substrate. This ensures that the encapsulation sheet is already prepared with the correct cutting guidance structure, and when the peripheral parts are removed, the encapsulation sheet maintains its full-size support function without creating step heights that could lead to cracking.
Data Source
AI summary
A method of manufacturing an organic light-emitting display apparatus includes: preparing a substrate including a display unit and peripheral parts; forming a cutting line on an encapsulation sheet to correspond to a boundary line between the display unit and the peripheral parts, wherein a size of the encapsulation sheet corresponds to that of the substrate; adhering the substrate and the encapsulation sheet together; removing the peripheral parts of the substrate; and cutting the encapsulation sheet along the cutting line. According to the method, a step height is not generated between the substrate and the encapsulation sheet when cutting the substrate and thus cracks may be avoided. Accordingly, products may be stably produced.