5G deployment is in full swing with mid-band infrastructure installed by the end of 2021 representing nearly 6 times what it was in 2019. However, this doesn't mean that all of the challenges have been solved. Much of the 5G infrastructure is repurposed 4G equipment at lower frequency bands. The real transition to 5G comes from the adoption of higher frequencies which have largely been categorised into sub-6 GHz and mmWave (> 20 GHz) bands. One of the key challenges is thermal management. As 5G deployment transitions to higher frequency, the antenna design, technology and material choices transition too. This will impact several factors such as the semiconductor technology, the associated die attach materials and thermal interface materials.
IDTechEx expects much of the infrastructure deployment in the short term to be in the lower frequency sub-6 GHz band. Later into the decade, we expect a significant increase in mmWave installations where more units will be required to provide sufficient coverage
https://www.idtechex.com/en/research-report/thermal-management-for-5g-2022-2032/857