This paper is co-authored by two of our member companies, Henkel Corporation and LPKF Laser & Electronics AG
Laser Direct Structuring and Liquid Semiconductor Encapsulants May Hold the Key to Increased Function for Certain Applications
As mobile 5G and 6G electronics advance and data traffic explodes, innovation in IC designs to incorporate expanded function, improved high-frequency shielding performance, better reliability, and lower power consumption are required. To enable the ongoing miniaturization of mobile devices in combination with improved performance, new techniques that leverage existing architectures to integrate additional active electrical functions have been explored.
One application is mobile antennas. Data send and receive signals in mobile devices are managed, in large part, through the mobile antenna. If mobile antennas’ real estate could be allocated from existing structures by leveraging the IC’s mold compound to add active electrical functionality, then even more capability can be integrated into current device footprints.
With this technique, known as active mold packaging (AMP), unutilized areas of the IC package’s epoxy mold compound (EMC) are allotted for metallization layers to deliver an alternative for mmWave applications. Using the standard well-known electronic processes of EMC, laser technology for laser direct structuring (LDS), and additive copper metallization, circuits can be created for various applications. This AMP approach with LDS technology is used today and is well-understood. However, the challenges with current processes center around limitations with the mold materials. All available EMC materials for LDS are granular or powder-like solids that have difficulty achieving thin layers, are not automation- and cleanroom-friendly, and may pose health and safety concerns.
This paper explores an active mold packaging (AMP) process using a laser direct structuring (LDS) technique and the use of two novel encapsulant technologies – a liquid compression molding material and a printable LDS material – to facilitate thin layers and fine lines and spaces. With this method, unutilized areas of the IC’s epoxy mold compound (EMC) are earmarked for additive metallization to create circuits and provide a mmWave application alternative.
While this approach has been explored and employed previously, there are limitations with the solid mold materials generally used. They cannot achieve the thin layers required for contemporary designs, are challenging to automate, and may present some health and safety concerns. Liquid-type materials overcome many of these challenges and, in combination with LDS, offer other functional enhancement opportunities such as thermal control, wire bonding alternatives, and EMI shielding.
