Everyday electronics like our cell phones function in large part thanks to microelectronics packaging. Microelectronics packaging allows us to pack billions of transistors into really tiny spaces, like silicon chips. Transistors communicate in an Integrated Circuit (IC) and microelectronics packaging helps connect all of these ICs to each other. Learn more about how microelectronics and semiconductor packaging works.

My first job after graduate school was as a microelectronics packaging engineer. When I told my parents this, their first question to me was whether I was going to be responsible for bubble wrapping laptops before they were shipped.

While packaging microelectronics for shipping is an important activity, it pales in comparison to the sheer complexity and significance of building devices that have features that span seven orders of magnitude. Yes, seven orders. 

The smartphone in your pocket has a piece of silicon in it with tiny devices called transistors that have structures as small as a few nanometers. When you swipe the screen of your centimeters wide smartphone with your finger, these transistors are in conversation with each other to interpret that swipe and respond to it. How do these tiny, very tiny, transistors communicate with you and your relatively colossal finger? How does all this happen reliably, day after day, season after season, while weathering multiple impacts of your phone on the ground and the occasional drop into the swimming pool? The answer lies in microelectronics packaging.

The semiconductor revolution we’ve had these past fifty years owes a lot to our ability to pack transistors into really, really tiny spaces. Billions of transistors are housed in a typical silicon chip, all communicating with each other in what we call an Integrated Circuit. But unless these transistors can communicate with the world beyond their confined existence, they would not be of much use. Packaging is the key to enabling the silicon chip to play its role in modern microelectronics – and it does this in four different ways.

Firstly, packaging connects different integrated circuits to each other. This is how a Central Processing Unit or a CPU, which is the core calculating engine of a microelectronics device, accesses and writes to memory, for example. Good packaging ensures these communications happen with minimum delay or loss of the signal. Secondly, packaging provides power to the IC, managing the incoming current to the right level appropriate for each IC, a field called power delivery. Thirdly, packaging protects the IC to ensure it is reliable enough to survive the conditions electronics are subject to – from the chip under a car hood that experiences wide temperature swings, to the one in your smartphone that is turned on and off a hundred times a day and travels everywhere you do. Finally, packaging removes heat. You may have noticed that electronics equipment tends to get hot after prolonged and intensive use. If this heat is allowed to accumulate within the silicon itself, it can damage the ICs. Good packaging pulls this heat out of the silicon and provides it a pathway into the external world where it can be dissipated.

How does packaging achieve all of these remarkable accomplishments? Much like the body uses nerves, packaging employs what we call interconnects of different kinds – from tiny solder balls to wires – to connect ICs to each other. Just as bones and muscle create the structure for these nerves to reach every fingertip, a substrate with copper traces is used to support the ICs and the interconnects. Just as sweating through our skin and pumping blood through our body keeps our brain temperature manageable, different solutions such as heat sinks, heat pipes and fans keep ICs cool.

I find packaging amazing. And not just for how we are able to span those seven orders of magnitude, from nanometers to centimeters, but also because of how it leverages several different disciplines of engineering: materials science, mechanical engineering, thermal engineering, electrical engineering and more. If you enjoy learning at the intersection of the engineering sciences, I would argue there are few areas of study and discovery as rewarding as microelectronics packaging.