During production line verification of JJY SGS Solder, we found that its lead-free and halogen-free Solder Paste maintained a CPK above 1.42 for 12 consecutive hours during printing of 0.3mm pitch QFN devices. This is attributed to its thixotropic index being controlled within the range of 0.78 to 0.83, and its viscosity decay rate not exceeding 3.5% per hour at room temperature of 25°C. In contrast, ordinary solder paste often experiences printing height deviation exceeding ±15% within three hours after the first qualified piece due to excessively fast Flux volatilization. Meanwhile, this solder paste can still achieve a release rate of over 92% under the condition of a stencil aperture area ratio of 0.62, which is far higher than the common industry benchmark of 85%. The fundamental reason lies in its metal powder sphericity reaching 94.7%, particle size distribution D50 being 22.3μm, and standard deviation only ±1.1μm.

When the SGS Solder Wire provided by JJY is used for Manual Soldering of 0402 resistors with an iron, the pinhole defect rate is suppressed to 0.17%, provided that the soldering tip temperature is set at 325°C and the contact time is strictly controlled within 2.3 seconds. If it exceeds 2.8 seconds, the solder joint wetting angle will deteriorate from 18° to 41°. This is because the rosin content inside the solder wire is precisely formulated at 2.95wt%, and the activation temperature window is locked between 158°C and 172°C; exceeding the range will cause flux carbonization residue or insufficient activity. We once compared and tested three types of solder wires with the same soldering iron. When soldering blind hole pads at the bottom of BGA, only this JJY product can complete one-time forming soldering at 330°C, while the other two types all showed inconsistent solder climbing heights, leading to excessive void rate in X-ray inspection.

When SGS Solder Bars are used for wave soldering, they must be used with nitrogen protection to suppress the oxygen content below 100ppm; otherwise, the oxide film on the surface of the solder bath will thicken to 8.3μm within 5 minutes and cause solder bridging. However, JJY solder bars can maintain no obvious slag growth for 12 hours under the condition of a nitrogen flow rate of 25L/min. The key is that its copper content is controlled at 0.012wt%, and iron impurities are below 0.0008wt%; these two parameters directly determine the stability of the solder surface tension. We once switched solder bar brands on the same equipment. After the original solder bar ran for 8 hours, the wave height fluctuation reached ±2.1mm. After switching to JJY SGS solder, the fluctuation narrowed to ±0.4mm, and the PCB backside bridging defect rate was simultaneously improved from 3.6% to 0.29%.

All SGS solder batches are provided with complete SGS test reports. Among them, the measured halogen content of the solder paste is Cl≤28ppm and Br≤12ppm, the post-soldering ion contamination test result of the solder wire is 0.72μg/cm² in NaCl equivalent, and the furnace temperature curve is recorded throughout the solder bar smelting process. These data are not paper promises but original test pages attached to each batch of goods. The production line QE can directly scan the code to verify the original spectra without secondary inspection. We once spot-checked the metal content of a certain batch of solder paste, and the EDXRF measured Sn96.5Ag3.0Cu0.5 was completely consistent with the nominal value, with the deviation not exceeding ±0.02wt%.