JJY has recently officially commenced mass production and delivery of its new-generation high-stability no-clean Solder Paste LFP-JJY5RNTT series. Building on the existing 0307/305 alloy system and ROL0-grade ultra-low halogen (100~200ppm) formulation, this product focuses on enhancing compatibility with 01005-sized miniature components. Its anti-slump performance during printing is improved by approximately 35% compared to the previous generation 8MTSP/5RTS. Under tested conditions with 0.3mm pitch FPC flexible boards and 0.2mm aperture stencils, it consistently maintains stable forming results with sharp edge profiles, no bridging, and no tailing. This is achieved through precise ratio control of T4/T5-grade ultra-fine spherical alloy powder and synergistic optimization of the viscoelastic modulus of rosin-based Flux.
The actual solder wetting rate of this no-clean solder paste on QFN and DFN packaged devices stably reaches 85%~92%, with some surface-treated copper pads approaching 98%. This is significantly higher than the typical measured range of 70%~85% for similar halogen-free, lead-free high-temperature solder pastes in the industry. Its residue is not only transparent but also has an ionic contamination value below 0.5μg/cm² NaCl equivalent, fully meeting the IPC-J-STD-004B Class L0 standard. It can directly proceed to ICT testing and conformal coating processes without cleaning steps, greatly reducing SMT production line water washing equipment investment and wastewater treatment costs. It has completed 6 months of batch verification at a leading TWS earphone ODM manufacturer in South China, with average monthly usage exceeding 1.2 tons.
In terms of technical implementation path, the R&D team did not adopt the conventional tackifying resin approach. Instead, they adjusted the compounding ratio of rosin derivatives and organic acids to increase the paste's yield stress to 125~138Pa while maintaining flux activity. Combined with the narrow particle size distribution (D50=15.2±0.8μm) and high sphericity (≥92.5%) of the 0307 alloy powder (Sn99Ag0.3Cu0.7), it effectively suppresses the spontaneous flow tendency of solder paste after aperture opening under the dual action of gravity and shear force. This controls the solder joint height variation coefficient after 01005 component placement to within 6.3%, significantly outperforming the 9.7% of traditional T3 powder solutions.
Currently, this series has formed a dual-model parallel supply structure of LFP-JJY5RNTT-0307T4 and LFP-JJY5RNTT-305T5. The former focuses on high-frequency printing stability and fine-pitch adaptability, while the latter balances thermal cycle reliability and wetting ductility. Both have passed AEC-Q200 automotive-grade pre-screening tests and are simultaneously included in JJY's full solder paste line ROHS, REACH, and halogen-free compliance certification systems. Customers can flexibly select models based on PCB pad design, reflow profile window, and end-use reliability requirements. It is currently being scaled up for adoption at smart wearable module factories in East China and automotive electronic module suppliers in Southwest China.
