Additively deposited interconnects as wirebond replacement in electronic packaging can have many advantages.
They can reduce or eliminate the loop and the associated inductance, which is important in high frequency electronics.
They can shorten the inteconnets, thus reducing loss. They can - depending on the printing technique- narrow the pitch and wire width down to 20 and 10um, respectively.
They can enable custom shapes for the interconnects, enabling one to have custom resistance values.
Finally, they can save space, as no bond pads will be required and can be more delicate as it is a non-contact deposition technique.
Here, we can see an example by Optomec. A microstrip is aerosol jet printed (AJP) with a width of 45um using silver nanoparticle (Ag NP) inks.
The data here suggests that wirebonds perform poorly at mmWave signals whereas AJP micrtrops can operate well upto 100 GHz. Of course, it is important to note that wire bonding is not as bad as this because often circuit compensation is built in. Furthermore, at such high frequencies, the competition is often not wire-bonding, but package-level integration.
Clearly, digital additive techniques like aerosol have many advantages. They still need to prove produciton at scale, reliability, etc. The conductivity of the printed lines- especially when the curing T is limited- needs to further improve as otherwise it becomes the dominant loss factor
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