Laminated Structure Polyester Protective Layer Peeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dry film photoresists face issues with peeling properties and electrostatic interactions, leading to defects such as short-circuits, scratches, and static electricity during the manufacturing of printed circuit boards, due to the formation of air holes and coarse particles at the interface between the protective and photosensitive resin layers.
Innovation Solution
A laminated structure with a protective polyester film layer having a maximum surface roughness between 1,500 nm and 2,500 nm and a sheet resistance between 1×10^8 Ω/□ and 1×10^12 Ω/□, which enhances the peeling property and reduces electrostatic interaction, preventing slip, wrinkles, contamination, and residual air holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polyethylene protective layer is used, then flexibility and chemical resistance are improved, but fish eyes form during polymerization causing air holes and defects
Solution Approach 1:
The patent changes the material parameter from polyethylene to polyester film, fundamentally altering the chemical composition to eliminate polymerization gel formation. This parameter change resolves the fish eye defect while maintaining the required chemical resistance for protective layer functionality.
Solution Approach 2:
The patent adopts a disposable polyester protective layer that is peeled off after use, eliminating the need for complex polymerization processes. This approach trades material permanence for process simplicity and defect-free production.
2Manufacturing precision
If polyethylene terephthalate film is used as protective layer, then fish eyes are avoided, but coarse particles form increasing adhesion and causing fracture during peeling
Solution Approach 1:
The patent precisely controls the surface roughness parameter of the polyester film within 5.0 nm≦SRa≦25 nm, optimizing the balance between adhesion and peeling properties. This parameter optimization prevents both fish eyes and excessive adhesion that would cause fracture.
Solution Approach 2:
The patent applies localized surface treatment to the polyester film to create specific roughness characteristics only on the surface layer, maintaining uniformity while enabling controlled adhesion properties for easy peeling without fracture.
3Manufacturing precision
If surface roughness and summit density are decreased, then fish eyes are avoided, but friction coefficient increases causing scratches and static electricity
Solution Approach 1:
The patent optimizes the surface roughness parameter to a specific range (5.0 nm≦SRa≦25 nm) that simultaneously prevents fish eye formation and maintains low friction coefficient. This precise parameter control eliminates static electricity generation while ensuring surface uniformity.
Solution Approach 2:
The patent uses polyester film with specific surface characteristics that combines smoothness for low friction with appropriate roughness for defect prevention, creating a composite structure that addresses multiple conflicting requirements simultaneously.
4Ease of operation
If conventional protective layer is peeled off, then electrostatic interaction occurs causing foreign substance adhesion and spark discharge
Solution Approach 1:
The patent modifies the surface electrical properties of the protective layer by controlling sheet resistance through surface treatment, reducing electrostatic charge accumulation during peeling. This parameter change enables easy peeling without spark discharge or foreign substance adhesion.
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 specified surface roughness and sheet resistance of the protective layer ensure easy peeling without residual photosensitive resin and minimize electrostatic issues, improving the quality and reducing defects in the circuit pattern formed on printed circuit boards.
Implementation Method 1
the strong electrostatic interaction produced when the protective layer is peeled off, foreign substance may adhere to the film and it is very likely that spark discharge may occur
Implementation Method 2
gels with a high molecular weight may be generated during polymerization of polyethylene
Data Source
AI summary
A laminated structure for use as a thy film photoresist, which includes a supporting layer, a photosensitive resin layer and a protective layer. The protective layer is a polyester film that has a maximum surface roughness between 1,500 nm and 2,500 nm, and a sheet resistance between 1×108Ω/□ and 1×1012Ω/□. The laminated structure is particularly applicable to the manufacture of a photosensitive device and a circuit of a printed circuit board or a lead frame.