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Indium8.9HF Solder Paste: Material Comparisons for Soldering Process Issues

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  • Phil Zarrow: Brook, I understand you've been doing a lot of work in material comparisons. What have you found? Is there any one particular standout?
    Brook Sandy-Smith: So my go to paste right now is Indium8.9HF. I choose it because the largest segment of the industry is using ROL0 fluxes, for solder paste with lead-free, and Indium8.9HF is and ROL0 meaning it's halogen-free but it still has a really wide process window and is really good for a lot of applications, including automotive applications, cell phones, servers, large boards, small boards, and everything in between.
    Phil Zarrow: So what are some of those processes, window wideners, if you will? What are some of the areas where it really stands out that way?
    Brook Sandy-Smith: Well my latest work that I've done with Indium8.9HF is on its stability. So, a lot of times we'll set a shelf life based on best practices. But, I started doing testing with Indium8.9HF to see how long does this solder paste really last?
    Phil Zarrow: Push the envelope?
    Brook Sandy-Smith: Right, and I've tested it for a really long time at room temperature, even. It definitely lasts a long time in refrigeration also, and the shelf life was extended to a year for lead-free in refrigeration and a month at room temperature. 
    But, I think it's also really interesting that if you're in a high mix environment, where you have a lot of product changeovers, sometimes long pauses. This paste is really stable on the stencil, so for up to 60 hours stencil life, you can get around these long pauses. It just gives you that much more confidence, that if you have to wait for two hours, it's definitely going to be good.
    Phil Zarrow: Right, because things happen. Yeah absolutely.
    Brook Sandy-Smith: Things happen. You might have to leave it overnight, although that's not a best practice.
    Phil Zarrow: Yeah, yeah we know, like I said, it happens.
    Brook Sandy-Smith: But it gives us that confidence that even if the paste is getting toward the end of the shelf life, that it's still going to perform the way that you expect.
    Phil Zarrow: Right.
    Brook Sandy-Smith: And, it's not going to cause any problems.
    Phil Zarrow: Yeah, how's it do with voids and QFNs?
    Brook Sandy-Smith: Ah, well it has some of the best QFN voiding in comparisons that I've run. Even sometimes contending with halogen-containing materials, which, you know, conventional wisdom would say "Don't compare halogen-containing to halogen-free."
    Phil Zarrow: Right, right.
    Brook Sandy-Smith: Because halogen's always at a disadvantage. But, this particular paste just has the right process window and the right performance for all of these applications.
    Phil Zarrow: So for more information on this, we can go to the website?
    Brook Sandy-Smith: Yes, or you can email me directly at
    Phil Zarrow: Brook, thank you so much.