Medical sensors impose extremely stringent requirements on the long-term stability and biocompatibility of solder joints. After JJY Sensor Soldering Solder completes Reflow Soldering at a peak temperature of 235°C, the shear strength of the solder joints remains stably above 28MPa. Meanwhile, no microcrack propagation is observed in thermal cycling tests (-40°C to 125°C, 1000 cycles). This is attributed to the precisely incorporated composite trace elements of bismuth and germanium in its tin-silver-copper matrix, which not only suppresses excessive growth of the IMC layer but also avoids the risk of chloride ion migration caused by traditional halogen-containing Fluxes.

Our mass production line tests at an IVD equipment factory in Shenzhen found that after using this sensor soldering solder to replace the original halogen-containing Solder Paste, the AOI missed detection rate dropped from 0.37% to 0.09%. This is mainly attributed to the more uniform surface tension during solder melting, approximately 18% faster wetting and spreading speed, and the post-soldering residue being in a transparent glassy state rather than white crystalline form, completely eliminating the hidden danger of moisture penetrating into PCB buried vias during the cleaning process, which would otherwise cause subsequent high-temperature failures.

The lifespan of SMT machine nozzles has also been extended by 2.3 times. This is because the active agents in this solder have undergone special complexation treatment, reducing adhesion to the wall surfaces of stencil apertures by 35%, resulting in more thorough printing release. After 8 hours of continuous operation, there is no obvious clogging at the bottom of the stencil, whereas traditional no-clean solder already exhibits a 12% decrease in aperture rate under the same conditions.

For miniature NTC thermistors with package dimensions smaller than 1.0×0.5mm, we recommend controlling the heating slope in the reflow zone to within 0.8°C/s and using it in conjunction with a nitrogen atmosphere (O?＜100ppm). This can reduce the solder joint void rate to below 3.2%. Otherwise, voids concentrated at the edges of the pads will directly weaken the heat transfer efficiency, causing clinical body temperature monitoring deviations exceeding ±0.15°C.

The rosin-based carrier of JJY sensor soldering solder completely decomposes at 217°C, with a residue dielectric strength of 28MV/m, far exceeding the 15MV/m threshold required for medical electronics. This means that even after 2 years of continuous operation in high-humidity environments (RH＞90%), the insulation resistance between solder joints can still be maintained above 1.2×1012Ω, without inducing signal drift or excessive leakage current.

A batch rework case of ventilator pressure sensor modules at a tertiary Class A hospital showed that the original halogen-containing solder batch exhibited 3.8% zero-point drift exceeding the tolerance after 6 months. After switching to this halogen-free no-clean solder and tracking for 18 months, the maximum drift was only 0.02kPa, fully meeting the long-term stability requirements of YY/T 0664–2020 for active implantable sensors.