𝐈𝐧𝐬𝐢𝐝𝐞 𝐃𝐢𝐫𝐞𝐜𝐭𝐏𝐂𝐁’𝐬 𝐐𝐮𝐚𝐥𝐢𝐭𝐲 𝐋𝐚𝐛 𝐑𝐞𝐯𝐢𝐞𝐰: 𝐇𝐨𝐰 𝐖𝐞 𝐂𝐚𝐭𝐜𝐡 𝐖𝐡𝐚𝐭 𝐎𝐭𝐡𝐞𝐫𝐬 𝐌𝐢𝐬𝐬 (𝐏𝐚𝐫𝐭 𝟐)

𝘈 𝘭𝘰𝘰𝘬 𝘢𝘵 𝘵𝘩𝘦 𝘦𝘲𝘶𝘪𝘱𝘮𝘦𝘯𝘵 & 𝘱𝘳𝘰𝘤𝘦𝘴𝘴𝘦𝘴 𝘴𝘵𝘢𝘯𝘥𝘪𝘯𝘨 𝘣𝘦𝘵𝘸𝘦𝘦𝘯 𝘺𝘰𝘶𝘳 𝘣𝘰𝘢𝘳𝘥 𝘥𝘦𝘴𝘪𝘨𝘯 & 𝘢 𝘥𝘦𝘧𝘦𝘤𝘵𝘪𝘷𝘦 𝘴𝘩𝘪𝘱𝘮𝘦𝘯𝘵. (Read Part 1 here).

𝗡𝗶𝗰𝗸𝗲𝗹 𝗖𝗼𝗿𝗿𝗼𝘀𝗶𝗼𝗻 𝗖𝗼𝗻𝘁𝗿𝗼𝗹: 𝗦𝗼𝗹𝘃𝗶𝗻𝗴 𝘁𝗵𝗲 “𝗕𝗹𝗮𝗰𝗸 𝗣𝗮𝗱” 𝗣𝗿𝗼𝗯𝗹𝗲𝗺 𝗕𝗲𝗳𝗼𝗿𝗲 𝗜𝘁 𝗥𝗲𝗮𝗰𝗵𝗲𝘀 𝗬𝗼𝘂

If you’ve specified ENIG (Electroless Nickel Immersion Gold) surface finish, you’ve likely heard of “black pad” — a form of nickel corrosion that can occur under the gold layer and lead to brittle, unreliable solder joints that pass initial inspection and fail later under stress.

It’s one of the most reputation-damaging defects in the industry precisely because it’s invisible until failure.

How we control it:

•     KYKY-EM6900 Scanning Electron Microscope with EDS. We pair high-magnification SEM imaging — which resolves nickel surface morphology down to the nanometer scale — with Energy-Dispersive Spectroscopy, which identifies the elemental composition at any suspect site. This SEM+EDS combination is the industry-standard diagnostic pairing for confirming (or ruling out) black pad corrosion, not a guess based on surface appearance alone.

•     Morphology and composition analysis, side by side. We don’t just look — we measure. SEM imaging shows us the microscopic form of any corrosion (pitting patterns, surface irregularities), while EDS spectroscopy tells us exactly what’s chemically present at that site, giving us a root-cause answer rather than a visual impression.

Root causes we screen for: environmental exposure to sulfur-containing gases, chemical bath contamination from chloride ions, deviations in nickel plating parameters, and gold layers thin enough to lose their protective function.

Each has a distinct signature under SEM+EDS, and identifying which one is at play is what lets us fix the process, not just flag the symptom.

Why it matters to you: black pad failures typically surface after your product has already shipped to your customer.

Catching the corrosion signature at the material level, before the gold finish leaves our facility, is the difference between a quality control line item and a field recall.

𝘐𝘯 𝘵𝘩𝘦 𝘵𝘩𝘪𝘳𝘥 𝘢𝘯𝘥 𝘧𝘪𝘯𝘢𝘭 𝘱𝘰𝘴𝘵, 𝘸𝘦’𝘭𝘭 𝘵𝘢𝘭𝘬 𝘢𝘣𝘰𝘶𝘵 𝘤𝘳𝘰𝘴𝘴-𝘴𝘦𝘤𝘵𝘪𝘰𝘯 𝘤𝘰𝘯𝘵𝘳𝘰𝘭.