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MAY 2025 I SMT007 MAGAZINE 69 Figure 2: It's essential to remove the gold plating from their surfaces before soldering them into a PCB to prevent gold embrittlement. example, an "A1P2D3" classification means acceptable for Class 1, a process indicator for Class 2, and a defect for Class 3. Before Revision F, the "N1P2D3" classifi- cation applied to the gold removal require- ment. is meant no requirement for Class 1, a process indicator for Class 2, and a defect for Class 3. With Rev F, the requirements were altered to "N1D2D3," indicating no requirement for Class 1 and defects for both Class 2 and Class 3. is change necessitated gold removal for all high-reliability applica- tions, affecting a broad spectrum of the elec- tronics manufacturing industry. Under the current J-STD-001 Rev J require- ments, gold must be removed from at least 95% of soldered surfaces on through-hole component leads with a thickness of 2.54 µm (100 micro-inches), all hand-soldered through-hole leads regardless of thickness, all soldered surfaces of surface mount com- ponents, and solder terminals plated with 2.54 µm (100 microinches) gold thickness, along with all solder cup terminals regardless of thickness. IPC-J-STD-001 Rev J specifies that a dou- ble tinning process or dynamic solder wave may be employed for gold removal before soldering components onto an assembly. It also emphasizes that gold embrittlement in solder connections can occur regardless of gold thickness, especially when the solder volume is low or the dwell time during the soldering process is insufficient for the gold to dissolve throughout the solder joint. For through-hole components, as illustrated in Figure 2, it is essential to remove the gold plating from their surfaces before soldering them into a PCB to prevent gold embrittle- ment and maintain the integrity of the solder interconnection. Improper removal of gold from component leads and terminations before PCB assem- bly can cause solder cracks and field failures.