Mastering through-hole soldering is often a challenge for hobbyists using soldering irons, flux, and other tools. It’s reassuring to know that even large companies encounter bumps along the way. A prime example is Raspberry Pi, which has produced over 60 million boards that feature this kind of soldering.
Raspberry Pi boards blend through-hole and surface-mount devices (SMDs). SMDs make it easier to fit many tiny components onto a board using solder balls and flat contacts. However, bigger parts—like connectors that experience physical handling—still rely on through-hole soldering. This process involves pushing leads through holes in the board and applying solder to create strong connections.
The 40-pin GPIO header on Raspberry Pi boards is a key example of where through-hole soldering is essential. Components like the Ethernet and USB ports also require secure solder joints that can’t be achieved with surface-mount technology. “In the early days, these components were manually inserted. Later, robotics took over,” says Roger Thornton, Director of Applications at Raspberry Pi, in a recent blog post. After insertion, the boards would undergo wave soldering for additional support.
Today, Raspberry Pi boards enjoy a streamlined process. Through an inventive technique called intrusive reflow soldering, all components are now soldered simultaneously. This process, done in collaboration with Sony, their UK manufacturing partner, allows for precise component placement and integration. It enhances efficiency while also reducing the carbon footprint of the production process.
Interestingly, a recent industry report highlighted that companies embracing automated soldering techniques have seen error rates drop by up to 30%. This shows not just the advantages of modern technology but how far we’ve come from the days of manual soldering.
As technology evolves, through-hole soldering remains an important skill. Whether you are building your first project or refining your techniques, understanding these processes will enhance your confidence and results.