JJY LFP series halogen-free Solder Paste has recently completed batch process verification at multiple leading EMS manufacturers in East China and South China, with a focus on Reflow Soldering scenarios for QFN and DFN fine-package devices. Among them, the LFP-JJY5RQ-0307T4 model achieved an average solder climb height of 98.7% of the pin height on 0.4mm pitch QFN devices, with some production line batches stably approaching 100%. This result has been double-confirmed by X-ray and cross-section metallography, with the solder joint void rate controlled within 3.2%, a decrease of approximately 1.8 percentage points compared to the average level of similar halogen-free solder pastes in the industry.

This series of solder paste adopts the 0307 (Sn99Ag0.3Cu0.7) alloy system, with a melting point range of 221–227℃, which is compatible with the 240–260℃ peak temperature window of mainstream nitrogen reflow ovens. Combined with T4 grade spherical alloy powder and ROL1 grade rosin Flux system, the single halogen content is below 900ppm and the total halogen content is below 1500ppm, which not only meets the environmental protection requirements for halogen-free PCBA specified in IEC 61249-2-21 and JEDEC JESD22-A112B, but also avoids the wetting force attenuation problem caused by excessive dehalogenation. It particularly exhibits excellent capillary climb sustainability and oxide film penetration ability at the interface between QFN bottom pads and PCB copper surfaces.

Compared with the same manufacturer's LFP-JJY5RTS-0307 model (solder climb rate 70%–90%) and LFP-JJY5RNTT-0307 model (suitable for high-precision scenarios such as communications and laptops), the 5RQ series achieves a better balance between activity strength and residue transparency. Its post-soldering residue is uniformly light amber with good light transmittance, and can pass ICT and AOI optical inspection without additional cleaning. Moreover, after high-temperature and high-humidity accelerated aging test (85℃/85%RH/1000h), it still maintains an insulation resistance >1×10¹¹Ω, with no signs of ion migration observed.

The currently verified QFN package types cover the full size range from 3×3mm to 8×8mm, with pin counts ranging from 16pin to 124pin. Among them, on 64pin QFN devices with 0.5mm pitch and thermal pad opening area ratio exceeding 65%, the cold solder defect rate decreased from 0.37% (when using a certain international brand ROL0 solder paste previously) to 0.09%, and rework man-hours were reduced by approximately 62%. This data has been reproduced in the mass production of three power management chip module customer production lines for three consecutive months.

JJY also provides a supporting process support package, including reflow profile recommendation templates, stencil opening optimization parameters (recommended thickness 120μm, opening ratio 1:1.05), and wettability matching instructions for different PCB surface finishes (ENIG, OSP, ImAg). All LFP series solder pastes are produced under the dual-system control of ISO 9001 and IATF 16949, with a batch-to-batch activity fluctuation CV value <4.3%, ensuring long-term soldering stability and yield consistency for QFN-type devices on automated SMT production lines.