Question: We all have from time to time had solder, be it in paste or wire form, sitting on shelves for what seems like years. I know there are all types of variables related to its’ longevity, but given this, what’s really going on with the expiration dates and are there tests you can perform to validate or extend this period?
Question: We are having a discussion about whether or not solder can touch a component body; in particular, we have a plastic SMT component where the solder has wicked up to the body on the legs. Sections are shown below. Is this condition acceptable under any circumstances, or is it always a reject in all three classes?
Question: I have always had in the back of my head that burnt flux is a defect for all class 3 assemblies. Upon further review I have not been able to identify the specific section of the IPC-A-610F standard which identifies burnt flux as an acceptable or defect condition.
Question: We are having a hard time with the removal of gold from hollow cup connectors. Using lead free solder, we are wicking the solder out with braid, but what is happening is that the pins are getting overheated and coming loose from the connector. Are there other methods we could explore?
Question: We have some PCB cards that are flooded with champagne size encapsulated bubbles. While no single bubble bridges between conductors there are numerous small bubbles similar to Figure 10-131 below, None have popped, as they are all encapsulated. Is Figure 10-131 a Defect Photo?
Question: The IPC lists different splices for wires including wrap, hook, mesh, and lap. We have all seen wires spliced together by twisting the two wires together forming a gentle twist before soldering. This splice would not have the physical strength of a wrap or hook splice, but it seems like it would offer at least the same strength as a lap splice with less aggravation, since the splice would stay in place during the soldering process. Why does the IPC not recommend creating this type of splice?
Question: We are working with components with leads of tin/lead over nickel. After the manufacturing processes, some of the pins are exhibiting what appears to be flaking plating, leaving behind unsolderable surfaces. They will re-tin with flux, but reappear following steam-aging. Is this something you have encountered before?
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”…
Question: Can Butane solder irons be used for soldering coax cable (pin on center conductor) or any other type of cabling? We are concerned about the temperature as compared to regular soldering stations.
Question: We have some PCB assemblies that show incomplete solder flow due to signs of flux exhaustion.