Issue link: https://iconnect007.uberflip.com/i/1207026
84 SMT007 MAGAZINE I FEBRUARY 2020 ical stresses are not going to be good for those particular alloys. Indium Corporation has developed a unique low-temperature alloy technology that pro- vides high drop-shock performance. Durafuse™ LT surpasses the drop-shock performance of bismuth alloys by two orders of magnitude and is comparable to SAC alloys when an opti- mal reflow process is employed. We'll be talk- ing about this technology a lot in the coming years as it gains traction in low-temperature applications. Matties: Do you see more jet technology for solder paste, probably more in North America than Europe and Asia? Nash: We see a trend with jetting all over the world, but a lot of times, it's going to be for niche applications, or it's going to be for low- volume, high-mix applications. These low- volume, high-mix applications have a lot of changeover, and the engineers don't want to buy hundreds of stencils for the vast amounts of products that they are building. Placing components in cavities is another application where we see jetting and/or dis- pensing technology becoming more popular. Indium Corporation has done a remarkable job with our materials, but we couldn't have done it alone. We've partnered with many of the jet- ting and dispensing equipment suppliers to ensure that we have materials that will work in their equipment sets and meet the end user's soldering requirements. I believe this technol- ogy is trending upward, but I also don't feel that jetting equipment will be taking over for stencil printing any time soon. Johnson: We started this conversation with the statement that solder, solder paste, and appli- cation technologies are the center of the chal- lenge in moving to smaller components. It seems to me like you're suggesting that a key part within that is flux. Nash: You're correct in saying materials are one piece of the puzzle; however, processes might be a bigger piece of the puzzle than materi- als. Going one step further within the material scope, flux and powder are your two big areas of concentration on miniaturization. Smaller deposits are going to need a finer powder sol- der paste. Manufacturing the finer powder is challenging, but we have the capabilities to do it. Standard mainstream applications are going to be using Type 3, 4, 5, and 6 powders at this point in time. Johnson: What I heard you say was that as boards get smaller, there's less flux overall, but the flux needs to do even more work at the same time. Nash: Yes, it's less flux, but because you have finer powder, you have more surface area, which means more oxygen content so that the flux has to work that much harder to clean the oxide off of the powder and the substrate met- allizations that you're soldering to. Then, it has to perform through a reflow process as well and not burn off to create any hidden pillow defects or coalescence issues. You still want to end up with a smooth solder joint that wets well at the end of the reflow process. The flux has to work that much harder, and there's less of it, so that's a challenge. Johnson: It doesn't sound like the challenge is in the powder. Nash: For many of the defects seen within the industry, the challenge is with the flux technol- ogy. The flux is the most important technology within the solder paste and soldering process to eliminate any end-of-line defects because it plays a significant role in printing and reflow. However, the process plays a significant role; It is important to ensure the flux technology is current and will handle any of the challenges that manufacturing sees.