The unique characteristics and success of the VSD™ materials are made possible through the marriage of nanotechnology and polymer chemistry.
Voltage Switchable Dielectric™ (VSD™) Material
A Voltage Switchable Dielectric™ (VSD™) material is a polymer nano-composite that functions as an insulator (dielectric) during normal circuit operation and becomes conductive when the voltage increases beyond a predefined threshold. The material becomes an insulator again after the voltage drops back below the threshold to normal operating levels. This unique property, coupled with the ability to tailor the voltage threshold, opens up several new areas in electronics.
While the VSD™ material functions as an insulator, the normal current path is not affected. When the rapid increase in voltage triggers the protection properties of the VSD™ material during an ESD event (i.e., clamping voltage), its ability to carry large amounts of current is enabled.
The key feature of the VSD™ material is its ability to clamp high voltage ESD events almost instantaneously. This animation shows the corresponding response of the VSD™ material to the ESD transient pulse over time.
How do VSD™ materials work?
The VSD™ material is placed adjacent to - and in contact with - the ground plane. During an ESD event, the voltage and current ramp almost instantaneously. If the circuit has proper access to the VSD™ layer, no matter where a high voltage pulse is introduced into the device, the VSD™ material will react to it by clamping the voltage and shunting the excess current to ground in less than a nanosecond. The net result is that all ICs mounted on the board or substrate are shielded from the transient voltage spike that would otherwise damage the chip. No matter where the high voltage static charge enters the product, the following animation demonstrates the path of the excess current as it is drawn away from the active and passive components, thereby providing full system level protection.
Our applications engineers and our customers (OEM/IDM) jointly perform an assessment of the product requirements that includes design, usage, operating life, etc., as well as the product’s existing or projected vulnerabilities to high voltage ESD. On-chip surge protection is also assessed along with system level architecture, material choices and construction. A clamping voltage that provides a sufficient protection buffer is then determined.
With the clamping voltage defined, integration into the product is accomplished in two ways:
a.
Through the physical integration of the VSD™ material within the board or substrate, and
b.
Through the layout of the traces and vias to enable proximity connection to the VSD™ layer.
All circuits and components with proximity connection to plated-through-hole (PTH) and blind vias in contact with the VSD™ layer achieve protection down to the threshold voltage that is now integrated into the system design. Additional detail on designing with VSD™ materials can be obtained by contacting our design and applications engineering team at sales@shockingtech.com.
