Assembly & Packaging

 l1 lite

We are often asked how we have achieved this level of miniaturization. It is the result of nearly 20 years of research at Uppsala University and ÅAC Microtec. In short, we have made significant breakthroughs in three areas.

Thin film instead of bond wires
Instead of relying on bond wires to make electrical connections, we have developed high density, fine pitch interconnects using thin film deposition. The advantages are many: faster transfer of information, less crosstalk, better heat conduction and simplified manufacturing. Due to the efficient dissipation of heat, fans are often made unnecessary.


MCM/SiP (multi-chip module/System-in-Package) with BGA interposer designed, prototyped and produced by ÅAC Microtec using XiVIA™ technology. Both SiP and interposer contain TSV interconnections

Through Silicon Vias (TSV)-holes instead of bond wires
To connect the vertically stacked wafer substrates, we have developed a technique that makes extremely robust vias through the silicon wafers. This proprietary technique, XiVIA™, is available for licensing.


pic2  pic3
SEM picture of ÅAC Robust Through Silicon Via (TSV), XiVIA™

XiVIA™ is a low-resistive (metallic) via compatible with silicon substrates ranging from thinned 300 µm to 800 µm wafers. The typical resistance of a 180 µm diameter via in a 300 µm substrate is less than 10 mΩ. XiVIA™ technology enables interposers, stacked memories (MCP), POP, Wireless-SIP, WLP RP-SIP, 3D-System-on-Chip (3D-SOC). XiVIA™ is extremely robust and has been space qualified, and was e.g. used in the development of the European Space Agency (ESA) motion control chip (MCC).

Mounting of bare dies
A bare electronic die is in itself very small. It is the die’s individual packaging that increases its typical size. At ÅAC Microtec, we have succeeded – with the help of our thin film technology and Under Bump Metallization (UBM) processes – in mounting fine pad pitch dies directly on silicon and ceramic substrates. In this way, we are able to manufacture complete systems – containing dies and MEMS sensors – in an extremely small package.

Right Now

Contact Us

ÅAC Microtec AB
Uppsala Science Park
Dag Hammarskjölds Väg 48
SE-751 83 Uppsala
Tel. +46 18 56 01 30
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Contact ÅAC USA: This email address is being protected from spambots. You need JavaScript enabled to view it.  
USA toll free Tel.  +1 (844) 831-7158

Follow Us