When "we" were manufacturing in the '90s the safe storage time for SMD was around 3 to 6 mths. Surfaces weren't 'fresh' after that. Some was wave soldered some reflow. If that is a slow moving component then maybe they coated it with a solder-thru protective layer? Doesn't seem like they used a low activity flux coating from that description. We had reasonable success with the solder-through enamelled copper wire coatings, but generally still had someone on the production line dip the ends of the coil/transformer leads in a solder pot. One of the main reasons iirc was that we had difficulty transitioning the inspectors from through-hole soldering to SMT. Historical note: I believe that NASA demonstrated that certain bad-looking joints were actually equal/superior to the ones that inspectors were trained for. It was TOO hard to characterise the iffy looking joints so that they could be reliably distinguished from bad joints. When SMT came along various inspectors nearly had breakdowns :-)
[I have no idea of current practices; and gee, THAT was 25 years ago! Feels like yesterday.] Hope you find out about that coating as I am rather interested too. John K -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Paul Andrews Sent: Tuesday, 20 August 2019 13:24 To: [email protected] Subject: Re: [neonixie-l] Q: Gold colored coating on surface mount contacts No. Still don’t know what it is. > On Aug 19, 2019, at 11:01 PM, Bill Notfaded <[email protected]> wrote: > > Did you figure it out Paul? Now you have me wondering too... > > Bill > > -- > You received this message because you are subscribed to a topic in the Google > Groups "neonixie-l" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/neonixie-l/qYuTkMwIVV4/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/015e1826-1302-4a5f-adca-ca706946fdf2%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/91C8E9B0-180E-4BAB-8F43-156BD34F86AA%40gmail.com. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/001b01d5571e%2459808d10%240c81a730%24%40internode.on.net.
