A Customer has a Problem
A customer approached us with a big problem. They had thousands of components they needed to solder to a PCB using BGA spheres, but they couldn’t solder them. The leads on the components were so badly oxidized they wouldn’t take solder.
Badly oxidized leads – a real problem and a common one.
Badly Oxidized Leads
Leads on components can oxidize when the components are kept in storage for any meaningful period.
But how do components go bad when their leads are typically tinned to prevent just this sort of thing?
The case of our customer offers up a good example. Yes, the leads on their components had been plated with Tin, creating a layer of Tin over the Copper of the leads. But over time the Copper can leach into the Tin creating a Tin-Copper matrix that is impervious to solder, which was a disaster for our customer. They thought their only solution would be to strip the plating off the component leads and then replate the leads with Tin, a costly and time-consuming process.
What did our customer do? They did what anyone should do when they have a problem soldering something. They called the flux experts at Superior Flux. After all, flux’s main job is to reduce oxides from a metal surface so that you can solder onto that surface.
Indeed, sometimes the only thing you need when you have badly oxidized leads is a strong flux that can eliminate the oxide layer off the leads so that it can accept solder.
But, in this case our customer’s component leads were so badly oxidized that none of the fluxes in our arsenal could eliminate them sufficiently to enable solder.
No big deal. Sometimes when a strong flux is not enough, we try out our Preflux Cleaners. We use these cleaners, usually in heated form, to remove particularly tenacious oxides before fluxing and soldering.
A New Preflux Cleaner is Born
So, we tried our Preflux Copper Cleaner, but it didn’t do the trick. Then we tried our far more aggressive Nickel Preflux Cleaner, but the oxides on these components wouldn’t budge. Then we did what we always do when one of our “off-the-shelf” products doesn’t do the job. We went to our lab, rolled up our sleeves, and formulated something new for this customer’s need.
The result is a new product called DPI-SCC-1. It’s a tacky paste that can be brushed onto badly oxidized leads. Once applied the leads are run through a reflow oven. After reflow and cool down, the leads are washed off with water-based cleaners and dried. And then…
Well, and then our customer was able to solder these once un-solderable components, which to our customer meant a lot. Now instead of having thousands of components that were a liability, they now had perfectly good components that could be soldered as though they were brand new.
Moral of the Story
The moral of the story? If you have a problem involving flux or soldering or brazing or even welding, contact the folks as Superior Flux and let us help!