Recently, we conducted on-site testing of our two Domestic Solder Pastes, JJY LFP-JJY5RQ-0307T4 and LFP-JJY5RR-305, at three LED driver board factories and one automotive lighting module factory in the Pearl River Delta. All samples passed the JEDEC JESD22-A108F high-temperature high-humidity bias test, 1000 cycles of thermal shock from -40°C to 125°C, and 1000 hours of high-temperature aging on the first attempt. No defective soldering cracking or ionic residue corrosion occurred at all. This is the combined result of the dense IMC layer formed by the 0307 alloy powder within the 240–260°C reflow window and ROL0-level halogen control. In particular, the 8M9P/5RR series achieves 0 ppm halogen and a void rate below the industry-recognized 3% threshold.

The strongest production line feedback came from the 8MQP/5RQ series. When used on 0.4mm pitch QFN packages, the wetting height stably stays above 95% of the pad height, and even approaches 100% on 0.3mm pitch DFN packages. The reason is that it uses T4-grade ultra-fine spherical 0307 alloy powder paired with a high-activity rosin carrier. Under conventional parameters of a 0.08mm stencil aperture, 4.5kg squeegee pressure, and 25mm/s printing speed, it still maintains sharp edges without slumping. While the 8MTSP/5RTS has slightly lower wetting, it leaves less residue that is also more transparent, making it suitable for fingerprint lock motherboards with stringent AOI recognition rate requirements.

Engineers working on automotive modules particularly favor the 8M9P/5RR. Its zero-halogen property, combined with 305 alloy powder, can suppress the void rate to 1.8% at a peak temperature of 255°C, which is 0.7 percentage points lower than a certain Japanese competitor. Moreover, the measured average solder joint shear force reaches 42.3N with a fluctuation range of only ±1.2N, indicating extremely strong batch-to-batch consistency. This is attributed to the ratio precision control of the organic acid activator and thixotropic regulator in its rosin system being within ±0.3wt%.

For laser welding scenarios, the 5RLJ series is recommended. It exhibits excellent dispensing continuity when used for air pressure valve dispensing, with a solder ball rate of 0 at a jet frequency of 50Hz. The key is that the surface oxide film thickness of the 00507BN alloy powder is controlled within 1.2nm, paired with <500ppm> water-washable type, choose 8MW1P/5RW1, SC07 alloy powder plus ORH1-type water-soluble Flux. After cleaning, ion chromatography shows Na+ < 0.2μg/cm2 and Cl- < 0.15μg/cm2, fully meeting the IPC-J-STD-001E Class 3 standard, while the cost is only 65% of imported water-washable Solder Paste. However, note that it cannot be used on silver-plated terminals, otherwise Ag?O black spots will form.

For soldering aluminum and stainless steel, 8MW5/5RW5 must be used. SC07 plus Sn42Bi58 composite powder can activate the aluminum surface oxide layer in the 210°C holding zone, and then the water-washable system removes intermetallic compound debris. The measured thrust of solder joints on aluminum substrates reaches 38.6N, far exceeding the 25N threshold specified by IPC-TR-579, while ordinary high-temperature solder pastes generally have thrust stuck between 18–22N on such substrates.