As a halogen-free, lead-free high-temperature Solder Paste launched by the company for laser micro-welding scenarios, the JJY 5RLJ series is core-positioned to solve common process pain points of traditional solder paste under instantaneous localized laser heating, such as solder ball spattering, uneven wetting, and whitish residue. Leveraging a rosin-based Flux system and T3 to T7 multi-gradient metal powder grading technology, this product significantly improves the rheological response consistency and surface tension regulation capability of the solder under laser heat sources, while preserving the inherent melting point range (221–227℃) of high-temperature alloy powders including 0307, 105, 305, and 00507BN, thereby ensuring full, bright solder joint formation and sufficient interfacial metallurgical bonding.
Actual production line verification shows that in laser Reflow Soldering of fine-package devices such as QFN and DFN, 5RLJ maintains a stable solder climb coverage rate of over 85%. When dispensed with pneumatic valves or jet valves, it delivers consistent dispensing and precise collapse control. Especially within the 200–300W fiber laser power range, the solder paste has strong controllability over its thermal melting time window, effectively avoiding spattering and increased void rate caused by local overheating. Meanwhile, its total halogen content is controlled below 500ppm at the ROL0 level, meeting the long-term reliability requirements of scenarios sensitive to ionic contamination, such as communication modules, high-frequency PCBs for automotive radar, and high-density FPCs.
Compared with other high-temperature solder pastes in the same series such as 5RQ or 5RTS, 5RLJ further refines the alloy powder particle size distribution toward T6 and T7, and introduces trace nickel and bismuth elements for composite modification, resulting in transparent post-soldering residue and higher insulation impedance stability. Unlike water-washable or ultra-low-temperature solder pastes, this product is strictly limited to a 240–260℃ soldering temperature range, which not only avoids the risk of solder explosion in the laser focus area common to medium and low-temperature solder pastes, but also prevents the wetting delay phenomenon that may occur in zero-halogen REACH series under extreme thermal cycles, forming an exclusive high-temperature solder paste technical path for the laser welding process chain.
Currently, 5RLJ has been batch-deployed in processes such as COB mounting and VCSEL device bonding at multiple domestic semiconductor packaging and testing enterprises and optical module manufacturers. User feedback shows that its solder joint consistency for pad sizes below 0.3mm is approximately 12% better than that of conventional high-temperature solder pastes, and no additional cleaning is required after soldering before direct entry into AOI optical inspection, comprehensively reducing production line changeover debugging frequency and rework costs. It has become one of the key material options for JJY in the laser solder paste segment, supporting customers in improving micro-assembly yield and process robustness.
