When 5G Equipment Solder is exported, complete inspection documents must be delivered simultaneously; otherwise, the entire shipment will be detained or even returned at the destination port. Last month, our three tons of SN96.5AG3.0CU0.5 Solder Bars shipped to Poland were returned by customs because the original records of the copper mirror corrosion test specified in Appendix B of EN 61249-2-21 were missing. Re-running the tests and sending the documents by air cost an extra four thousand euros in shipping fees. Inspection documents are not simply stamped certificates of conformity; they must be traceable to the melting temperature curve of each furnace batch, records of inert gas purity, online XRF composition scan spectra, and dynamic wetting force test curves from at least three different batches. Each spool of JJY Solder Wire has undergone these data collection steps before leaving the factory, with a unique QR code embedded; customers can scan the code to access links to the original database.

Customers have extremely strict requirements for impurity control in 5G equipment solder. In particular, the total content of lead, bismuth, and antimony must not exceed 30 ppm. Recycled Tin Ingots commonly used in conventional production lines often contain 0.012% residual lead, so we must switch to primary high-purity tin ingots and add a secondary vacuum degassing process after melting. Otherwise, even if the composition report meets the standards, bismuth-rich phases may still precipitate at the edges of BGA solder joints during actual Reflow Soldering, causing cold soldering or defective joints. Meanwhile, the fluctuation of silver content in the solder must be controlled within ±0.05%; otherwise, the melting range of the same spool of solder wire can differ by 1.8°C across different temperature zones, which directly leads to bridging or tombstoning on the tiny pads of millimeter-wave RF modules. We once reworked two hundred sets of AAU motherboards due to this issue, resulting in losses far exceeding the inspection costs.

Melting point inspection in export documents cannot only list the initial melting and final melting temperatures; DSC thermal analysis spectra must be attached, with the half-width of the endothermic peak at a heating rate of 2°C/min marked. This is because customers use this parameter to calibrate the PID algorithm of their reflow ovens. Each DSC spectrum in JJY's inspection reports is labeled with the instrument number, calibration date, and measured nitrogen flow rate. Wettability testing must use the copper plate method specified in IPC J-STD-002E rather than the solder ball method, and the wetting time must be accurate to the 0.5-second level. We use the Japanese Shimadzu DTA-2000 dynamic wetting tester, and perform baseline calibration with standard Solder Paste before each test to avoid misjudgment of the contact angle caused by copper plate oxidation.

Halogen content testing must clearly distinguish between ion chromatography (IC) and oxygen bomb combustion-ion chromatography combined method (CIC). EU customers mandate the CIC method because it can detect organic halogen forms, while the simple IC method only measures free halide ions. All JJY 5G equipment solder exported to the EU is tested using the CIC method, with the detection limit reduced to below 50 ppb. Tin whisker growth assessment must provide aging photos and SEM cross-sectional images after 1000 hours in an environment of 120°C/90%RH; it is not enough to simply write "no tin whiskers observed". Customers want to see the correspondence between grain orientation, Cu6Sn5 layer thickness, and tin whisker initiation points. The accelerated aging chamber in our laboratory automatically records temperature and humidity deviations daily, with data errors not exceeding ±0.3°C and ±1.5%RH.