Last week, at the Smart Systems Integration conference in Brussels IMEC announced it’s latest 3D SiP technology – the ultra-thin chip package (UTCP). The announcement came while I was at the IMAPS Device Packaging Symposium, which was also being attended by Eric Beyne, scientific director of IMEC’s Advanced Packaging and Interconnect Center, so I asked him for some more details.
Beyne told me the process involves embedding a thinned, 25µm die in polymer film to form a 3D structure. At this stage, Beyne said the Known Good Die (KDG) issue can be addressed, because the chip can be tested through the film. The resulting package is a vehicle for embedding either rigid or flex PCB using standard processes. After embedding, other components, such as a Texas Instrument DSP processor or a wireless sensor can be mounted above and below the embedded chip, leading to high-density 3D integration. If the UTCP is embedded in flexible or even stretchable substrate material, it’s ideal for wearable electronics.
Here comes the really cool part. Beyne explained some of the applications this technology is intended for. One is for measuring brain activity, and interest has been expressed by a hospital that performs epileptic analysis in children. It is less invasive than current methods, which, as Beyne put it, requires the patient to be hooked up with all sorts of wires, and then told to “behave normally.” Kind of hard for a child to do, wouldn’t you think? However, with the UTCP technology, a wireless sensor can be embedded into a stretchable substrate that is part of a hat worn by the child, and transmit signals remotely, so the child can certainly behave normally. Beyne says a similar concept could apply to sleep studies.
Beyne also noted that in the scheme of 3D technologies, these low volume biomedical applications would be difficult to achieve using TSV processes, and is another reason why it makes sense to develop embedded technologies as well. Which is why at IMEC, R&D is largely technology driven. “In the end, we need to have applications to fit the technologies,” noted Beyne. – F.v.T