Low-temperature Solder Paste Process Advantages

Reading time ( words)

Figure 5 shows the data for the 12-mil circles with AR=0.6, Figure 6 presents the data for 15-mil circles with AR=0.75, and Figure 7 presents the data for 20-mil circles with AR=1.


Figure 5: Response to pause data for AR=0.6


Figure 6: Response to pause data for AR=0.75


Figure 7: Response to pause data for AR=1.

Stencil Life

Stencil life was evaluated by measuring the printed solder paste volumes for a given aperture. The classification was made based on the solder paste volume variability between the different printing conditions. The time between prints was used as a process variable (one-hour intervals up to 12-hour intervals were used). Figure 8 shows the data for the 12-mil circles with AR=0.6, Figure 9 presents the data for 15-mil circles with AR=0.75, and Figure 10 presents the data for 20-mil circles with AR=1.


Figure 8: Stencil life data for AR=0.6.


Figure 9: Stencil life data for AR=0.75.


Figure 10: Stencil life data for AR=1.


For the reflow step, a seven-zone Vitronics oven was employed. The reflow profile employed for the low-temperature alloys and SAC305 spheres is shown in Figure 11.


Figure 11: Low-temperature reflow profile.



Suggested Items

High-reliability, Low-temperature Solder Alloys

05/18/2020 | Dr. Pritha Choudhury, MacDermid Alpha Electronics Solutions
Increased digitalization and greater connectivity have been driving miniaturization and more complex and integrated designs in electronics. As the real estate on PCBs shrinks, so does the size of packages. However, the drive for finding design solutions for increased performance has continued to expand. The solder joint is an essential part of assemblies for electronic devices as it provides electrical, thermal, and mechanical connections. Therefore, soldering materials have been evolving to enable such a technological revolution.

This Month in SMT007 Magazine: How Engineers Can Use SPI Tools for Verification

05/06/2020 | Nolan Johnson, I-Connect007
Koh Young’s Ray Welch and Brent Fischthal detail how engineers can work with SPI tools to verify how small they can go in component size with their solder paste application, and how the company’s SPI equipment is helping not only to verify but also to help drive the development collaboration between solder paste and stencil printer manufacturers, and inspection tools and software.

This Month in SMT007 Magazine: Indium Metal Forecast—Supply Chain Strong, Demand Continues to Grow

05/05/2020 | Donna Vareha-Walsh, Indium
Indium is a critical metal for the indium-tin oxide (ITO) market and other coating applications. Donna Vareha Walsh—director of sales and global supply chain and trade compliance at Indium Corporation—describes the plentiful global supply of indium and its recycling loop, examines indium’s history of price volatility and the market reactions from the recent Fanya Metal Exchange auction, and provides an overview of indium supply and demand drivers, as well as the impact of recycling efforts.

Copyright © 2020 I-Connect007. All rights reserved.