When you think of gold, you probably think of jewelry gold bars, even if you're old, like me, gold Slugger but gold is actually extremely common and important in electronics as well.
You've probably seen it on contacts for everything from Ram to HTMI to memory cards, but why is it used so widely? I mean, copper does a fine job of conducting electricity. So why do we need to use gold?
Well, you're right about copper, but gold is superior in some key ways that make it a really good choice for certain applications. For one gold is very nonreactive and resist corrosion and tarnishing, even though gold is slightly less conductive than copper. It still offers electrons extremely little resistance. And you don't have to worry about it. Reacting with chemicals in the environment as much as you do with copper. And considering that most electronic components use low voltages and current levels, a small amount of tarnish on the conducting material can have a big impact on signal integrity. So for intricate connections many manufacturers don't take their chances with anything other than gold.
This leads well into the next point. Gold is a soft, incredibly duct tile metal. It's very easy to work into any shape and size you might need. And although were can obviously be drawn into wire. Gold is even softer and can be stretched thinner, making it ideal. When you think about how small some of these connections are, we're talking only a few micrometers meaning gold softness combined with its relative. Non-reactivity make it a great choice.
In fact, gold is very popular for what's called wire bonding. The act of connecting a semiconductor dye to the package that holds it like what you might see on your typical desktop CPU.
Gold can carry a lot of heat without melting or cracking. So it won't hurt your performance just because it's inside the hot environment of your CPU package. This is especially important in automotive applications. Our cars are becoming packed with more and more electronics. Some of which control critical systems. You don't want an autonomous driving feature to fail when you're going down the highway at 70 miles an hour. So gold is used because it's resistant to the thermal and environmental hazards. Your car can encounter while it's in motion.
Additionally, gold is very easy for modern manufacturing devices to bond quickly. So it allows chips to roll off the line in large numbers, but gold is also useful for applications. You might actually see every day premium cables are sold with gold-plated connectors. Although this doesn't do anything to make your signal faster, it does keep the connector from wearing down as quickly.Although gold is a soft metal. It actually provides good resistance to wear and tear when it's aloid with a small amount of another metal such as nickel.
Gold is awesome. We love golf, but it's super expensive, right? How can we even afford our gadgets if all of this gold is in all of them? Well, it turns out that you don't need a whole lot of gold for most electronic applications. Since it's mainly used for a small, all intricate connections your typical smartphone contains less than a dollars worth of gold. So even though it's obviously more expensive than copper it's advantages still make it sensible choice in many situations.
But one thing keep in mind is that unfortunately not very much of the total gold used in electronics is ever reclaimed. This means that the cost of gold and manufacturing can and has gone up over time. So if you've got an old PC or phone that you're not selling and just need to dispose of, remember to recycle it properly and to help keep the price of gold under control.