Question: Regarding gold removal requirement under Section 4.5.1 of J-STD-001, it allows: “A double tinning process or dynamic solder wave may be used for gold removal prior to mounting the component on the assembly”.
Does this mean that if we run a through-hole CCA thru a wave solder machine twice it would meet the gold removal requirements?
If not, how would we tin the gold plated components by wave soldering?
Answer: Soldering gold parts onto printed circuit boards follows Paragraph 4.5.1 Gold Removal in J-STD-001 as you had mentioned.
The gold has to be removed from component leads whose gold thickness exceeds 2.54 micrometers or 100 micro-inches (.00001”) and from all components which will be hand soldered, regardless of gold thickness.
The double tinning process is for tinning the components prior to soldering them, and the need is to dip those components in the solder pot twice to remove the gold plating.
If the components are going to be wave soldered then just install them into the board and use the solder from the wave to dissolve the gold. There is enough solder in the solder pot to keep the gold concentrations low, so we don’t have to worry about high levels of gold contamination in the solder pot.
So to answer your question, you don’t have to tin the components that are going to be wave soldered into the board itself. If you are going to hand solder those components, then they have to tinned prior to being installed in the board and soldered.