Photosensitive Resin Composition for Multilayer PCB Via Resolution

The patent replaces the mechanical laser processing system with a photolithography system. Instead of using laser beams to physically ablate material, the invention uses light exposure through a photomask to define via patterns, followed by chemical etching. This substitution enables parallel processing of multiple vias simultaneously, dramatically improving production efficiency while achieving finer via diameter control through optical resolution limits rather than mechanical constraints.

The patent combines multiple processing steps into an integrated photolithography-based via formation process. The exposure, development, and etching steps are merged into a single workflow that can process entire arrays of vias in parallel, rather than addressing each via individually as in laser processing. This merging of operations is the core mechanism for achieving high-volume via production.

The patent employs a composite photosensitive resin composition containing multiple functional components: epoxy resin for adhesion and mechanical strength, phenolic resin for heat resistance and dimensional stability, cyanate resin for electrical insulation properties, and silane-modified components for enhanced crosslinking. This multi-component composite system simultaneously achieves high via resolution through photopolymerization, strong adhesion to plated copper surfaces, and excellent electrical insulation reliability, particularly under humid and high-temperature conditions.

The patent modifies the chemical composition parameters of the photosensitive resin to optimize multiple performance characteristics. By adjusting the ratios and types of resin components, crosslinking density, and additive concentrations, the formulation achieves a balance between photopolymerization sensitivity (for via resolution), adhesion strength to metal surfaces, and electrical insulation properties. The specific parameter optimization enables simultaneous satisfaction of multiple conflicting requirements.

The patent changes the material parameters of the interlayer insulating film by using a specially formulated photosensitive resin composition with enhanced dielectric properties. The composition includes high-performance resins and additives that increase the breakdown voltage and reduce moisture absorption, allowing the film to maintain excellent electrical insulation reliability even at reduced thicknesses. This parameter optimization enables circuit densification without sacrificing insulation performance.

The patent uses a composite resin system combining multiple polymer types with complementary properties. The mixture of epoxy, phenolic, and cyanate resins creates an insulating film with superior electrical breakdown strength and moisture resistance compared to single-resin systems. This composite material approach allows thin films to provide adequate insulation barriers, enabling higher circuit density while maintaining reliability under humid and high-temperature operating conditions.