Solder Paste inspection is not a perfunctory formality, but a mandatory hard threshold that must be completed before each batch goes online. Our production line requires that three actions—batch registration, sampling and packaging, and inspection handover—be completed within 24 hours of solder paste arrival. At the same time, the tank spray code, warehousing time, and warehouse location must be handwritten on the "Solder Paste Tracking Card". This card enters the constant temperature cabinet together with the solder paste; whoever picks it up signs, and whoever opens it marks the opening time. Because once solder paste is opened and exceeds 72 hours without temperature recovery and stirring, it tends to delaminate. Even if the SGS Solder paste inspection report is qualified, delaminated solder paste cannot be used for high-reliability products.

The RoHS limits in the SGS solder paste inspection report must be implemented in accordance with the latest version of IEC 62321. Lead content must not exceed 1000ppm, cadmium must not exceed 100ppm, and hexavalent chromium must not exceed 1000ppm. These values are hard thresholds; a difference of 1ppm is unacceptable. Meanwhile, the control of phthalate substances in REACH Annex XVII has been extended to the total of DEHP, BBP, DBP, and DIBP, which must not exceed 0.1%. Many procurement staff only look at the "compliant" conclusion column on the report and release it, but fail to notice whether the SGS solder paste raw data page actually tests all four items.

Halogen testing is often overlooked, but export automotive electronics customers explicitly require the total bromine + chlorine ≤ 900ppm. We once had a batch of solder paste rejected by customers because the SGS report only tested bromine and not chlorine. Later, we changed to mandatorily checking "full halogen items" for all solder paste submissions, and required SGS to note in the report remarks column that the test method is IEC 61249-2-21; otherwise, acceptance is not granted. Because the extraction efficiency of different methods can differ by up to 15%, not clearly stating the method is equivalent to not testing.

Batch traceability is not only checked when problems arise, but the process engineer randomly inspects 3 in-use batches before the daily morning meeting, verifying whether the last 4 digits of the SGS report number match the last 4 digits of the tank spray code, whether the report issuance date is earlier than the warehousing date of that batch, and whether the inspection items cover the customer's special requirements for the current order. For example, medical customers additionally require arsenic and antimony element testing, which are not included in the SGS solder paste routine package; missing these tests is equivalent to not testing at all.

The solder paste material code in the ERP system must be associated with a unique SGS report number. When the warehouse issues materials, scanning the code automatically pops up the corresponding report PDF, and the production line team leader confirms it is correct before unsealing is allowed. If the same number is found to appear twice, immediately freeze that batch and initiate a deviation investigation. Because in real production lines, SGS will never issue the same report for solder paste with different production dates; as long as the number is duplicated, one must be fake. We caught two such incidents at the Dongguan factory last year: one was a supplier copying an old report and tampering with the date, and the other was an internal document controller making an input error that caused a system mismatch.