Liquid Solder Resist Composition Surface Smoothness
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Solution Overview
Problem
The existing liquid solder resist compositions containing powdery hydroquinone epoxy compounds face challenges in achieving high surface smoothness and glossiness, leading to potential slip marks and metal powder adhesion, while also requiring time-consuming heating processes that decrease productivity.
Innovation Solution
A liquid solder resist composition comprising a carboxyl group-containing resin, a thermosetting component with a powdery epoxy compound having a specific melting point range, and a photopolymerizable component, which allows for photocurable and alkaline-developable coatings with improved smoothness and heat resistance, eliminating the need for pre-heating the hydroquinone epoxy compound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a powdery hydroquinone epoxy compound is contained in the solder resist composition, then the solder resist layer has good alkali developability, low tackiness, flexibility, heat crack resistance, and heat resistance, but the surface smoothness and glossiness of the solder resist layer decrease
Solution Approach 1:
The patent changes the physical state parameter of the hydroquinone epoxy compound from solid powder to liquid by heating it above its melting point (138-145°C). This parameter change allows the compound to be mixed homogeneously with other components to form a smooth liquid composition, while the heated liquid state is maintained during application and drying to prevent crystallization and precipitation, thereby achieving both good reliability and high surface smoothness
Solution Approach 2:
The patent utilizes the phase transition of the hydroquinone epoxy compound from solid to liquid state through heating. By maintaining the compound in its liquid phase during composition preparation and application, the patent achieves homogeneous mixing and smooth surface formation. The phase transition enables the compound to lose its crystalline structure that causes surface roughness while retaining its functional properties
2Manufacturing precision
If the hydroquinone epoxy compound is heated and melted in advance to improve surface smoothness, then the surface smoothness and glossiness improve, but equipment as well as time and effort for heating and melting are required, resulting in decreased productivity
Solution Approach 1:
The patent merges the heating process into the standard manufacturing workflow by incorporating the heating step within the existing coating formation process. The hydroquinone epoxy compound is heated to its liquid state and then applied to the substrate in the same continuous process, eliminating the need for separate heating equipment and operations. This integration maintains surface smoothness while improving productivity by reducing process steps and equipment requirements
Solution Approach 2:
The patent applies the heated liquid solder resist composition directly to the substrate without requiring additional cooling steps. The composition is applied and dried while maintaining the temperature above the melting point, allowing the process to proceed efficiently without external intervention for temperature management, thereby improving productivity
3Manufacturing precision
If the hydroquinone epoxy compound is heated in advance to prevent crystallization, then the surface smoothness improves, but cooling the solder resist composition is likely to cause crystallization and precipitation, making it difficult to apply and dry
Solution Approach 1:
The patent performs preliminary heating of the hydroquinone epoxy compound to its liquid state before application. By pre-heating the compound and maintaining it in liquid form throughout the application and drying process, the patent prevents crystallization and precipitation that would occur upon cooling. This preliminary action ensures both surface smoothness and ease of operation by keeping the composition in an applicable liquid state
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 results in a solder resist layer with enhanced surface smoothness, reduced tackiness, and improved heat resistance, preventing slip marks and metal powder adhesion, while maintaining productivity by eliminating the need for pre-heating and melting the hydroquinone epoxy compound.
Implementation Method 1
a liquid solder resist composition which has photocurability
Implementation Method 2
can be developed with an alkaline solution
Data Source
AI summary
The present invention aims to provide a liquid solder resist composition which can be formed into a solder resist layer which is glossy and has a highly smooth surface despite containing a powdery hydroquinone epoxy compound. A liquid solder resist composition according to the present invention contains a carboxyl group-containing resin (A), a thermosetting component (B), a photopolymerizable component (C), and a photopolymerization initiator (D). The thermosetting component (B) contains a powdery epoxy compound (B11) represented by following formula (1).