RO5880 is a high-performance high-frequency laminate prized for its low-loss characteristics. However, its smooth surface poses a challenge of relatively weak copper foil adhesion, making it prone to delamination under thermal or mechanical stress. Selecting the appropriate surface treatment is crucial for enhancing its reliability. Here are five effective surface treatment solutions to prevent delamination.

Solution 1: Optimize the Brown Oxide Treatment Process
This is the most fundamental and critical solution. For the smooth surface of RO5880, it is essential to use a specialized brown oxide (oxidizing) chemical designed for low-roughness substrates. This process creates a microscopically uniform and dense oxide layer on the copper surface, significantly increasing the surface area and mechanical interlocking force. This greatly enhances the bond between the inner layer copper foil and the prepreg (PP), preventing delamination at its root.

Solution 2: Employ Plasma Cleaning Technology
This is an advanced dry process treatment. Bombarding the board surface with plasma achieves two key outcomes: first, it thoroughly cleans the copper surface, removing organic contaminants and minor oxidation; second, it slightly roughens the surface at a microscopic level through physical bombardment and increases surface energy. This provides an extremely clean and highly active interface for subsequent lamination or solder mask application, significantly improving adhesion.

Solution 3: Apply Chemical Micro-etching
Before lamination, subject the copper surface of the RO5880 board to a controlled chemical micro-etch. This process uniformly etches away a very thin layer of copper through a chemical reaction, forming a microscopically rough structure with a specific profile. This structure creates a larger effective bonding area, allowing the flowing resin to better “anchor” to the copper surface. This provides excellent mechanical locking, resisting delamination stress.

Solution 4: Select High-Performance Bonding Sheets
Address the issue synergistically from the material system. Use high-performance bonding sheets compatible with RO5880’s properties, such as PP materials with higher resin content, lower flow, or specific chemical functional groups. During lamination, these bonding sheets can more effectively fill the micro-gaps on the copper surface and form stronger chemical bonds with the treated copper, enhancing bond strength from both sides of the interface.

Solution 5: Implement Combined Surface Treatment
For applications requiring the highest reliability, a combined treatment of “Brown Oxide + Plasma Cleaning” is recommended. First, perform the standard brown oxide treatment to establish a foundation for chemical bonding. Subsequently, conduct plasma cleaning to remove any residues potentially left after oxidation and further activate the surface. This dual assurance maximizes both chemical bonding and physical interlocking at the interface, providing the highest level of anti-delamination performance for RO5880.

Summary and Recommendations:
When selecting a solution, factors such as production cost, equipment availability, and product reliability requirements must be considered holistically. Typically, optimizing the brown oxide process (Solution 1) is the essential starting point. If conditions permit, adding plasma cleaning (Solution 2) or adopting the combined treatment (Solution 5) can significantly enhance quality. Simultaneously, close collaboration with material suppliers to match high-performance bonding sheets (Solution 4) is key to solving the problem from a systemic perspective.