As the size of devices requiring some form of spread-spectrum communications is decreasing, the problem of shielding noise-sensitive or noise-emitting parts of miniature digital and RF circuits is growing.
In today’s microminiaturized portable, wearable, and IoT devices, complete wireless radio transceivers are packaged onto modules which are themselves just one component in an architecture involving processor, memory, display drivers and user interface controllers.
As a consequence, electromagnetic interference (EMI) is a growing issue.
Up to now, the standard solution is to enclose noisy/noise sensitive components in shield cans. However...
They interfere with reflow thermal profile during assembly
They cover components, making cleaning, inspection, and rework problematic
They can have holes for thermal passage and cleaning, but these reduce EMI shielding integrity
They can have snap-on lids to permit cleaning, inspection, and limited rework
but the real bottom line is...
Shield cans just don't fit anymore
Form a Faraday Cage around the sensitive components, and make it very, very small.
This is what TransSiP’s patent-pending Trans-SHIELD™ technology does.
How it works
Depending on the topology of the circuit needing shielding, TransSiP's TransSHIELD™ technology forms micron-scale physical or "virtual" Faraday Cages inside a specially designed interposer around sensitive components or circuit functional blocks.
TransSHIELD™ does this by creating a 6-sided equipotential barrier formed by a ground/reference plane within the active circuit carrier, vias within the carrier and the TransSHIELD™ interposer, and plated or semi-plated cavities within the interposer itself.
- Smaller, Lighter- Integrated Carrier Package (ICP)
- More Reliable- cleaned, fully tested, hermetically sealed, less complex BOM
- High performance- optimized functional partitioning, DC-DC supply bias conditioned using JC™ technology
- Improved autonomy- longer battery life using high efficiency JC-PFM™ DC-DC conversion
Does TransSHIELD provide 100% EMI shielding?
Yes. The coating used in TransSHIELD™ cavities is highly conductive non-ferromagnetic material providing good electromagnetic shielding at high frequencies while enabling passage of Earth's magnetic field (good for compact design with electronic compass/Hall effect sensor) and the virtual ground plane created by interposer/carrier via arrays shields both electrical and magnetic wave components. The Faraday Cages formed within TransSHIELD™ are EMI-hermetic.
How much height does the TransSHIELD™ interposer add to the assembly skyline?
Depends on the number of layers needed for carrier I/O redistribution wiring between the shield cavity floor and interposer bottom side. Using HDI manufacturing and design rules, 6 redistribution layers can be provided within about 0.27mm (0.011").
What about testing and rework?
The assembled circuit carrier can be fully functionally tested and reworked before assembly into the TransSHIELD™ interposer and overmolding/covering.
The TransSHIELD™ interposer is a cavity package, and will cost more than a simple shield can. But-
- line QA is simplified
- thorough cleaning is possible
- active modules are reworkable
- functional testing is enabled before shielding
- assembly is simplified (simpler BOM / no shield can handling)
For the first time, very small assemblies can be individually and completely shielded.
How about availability?
TransSiP and our U.S. based manufacturing partner are ready now to support you with co-design and fabrication services, including the following:
- carrier layout partitioning assistance for Trans-SHIELD™ implementation
- carrier substrate fab (both PTH and HDI)
- carrier substrate assembly, including boundary test
- ICP interposer design and fabrication
- interposer-carrier assembly, test, and final packaging
Manufacturing facilities comply with the following certifications:
ISO13485, ITAR, Accredited NADCAP, MIL-PRF-55110, MIL-P-50884E, MIL-P-31032, and RoHS.