3D packaging saves space by stacking separate chips in a single package. This packaging, known as System in Package (SiP) or Chip Stack MCM, does not integrate the chips into a single circuit. The chips in the package communicate using off-chip signaling, much as if they were mounted in separate packages on a normal circuit board. In contrast, a 3D IC is a single chip. All components on the layers communicate using on-chip signaling, whether vertically or horizontally. A 3D IC bears the same relation to a 3D package that a SoC bears to a circuit board.
Microfluidics deals with the behavior, precise control and manipulation of fluids that are geometrically constrained to a small, typically sub-millimeter, scale. Typically fluids are moved, mixed, separated or otherwise processed. Numerous applications employ passive fluid control techniques like capillary forces. In some applications external actuation means are additionally used for a directed transport of the media. Examples are rotary drives applying centrifugal forces for the fluid transport on the passive chips. Active microfluidics refers to the defined manipulation of the working fluid by active (micro) components as micropumps or micro valves. Micro pumps supply fluids in a continuous manner or are used for dosing. Micro valves determine the flow direction or the mode of movement of pumped liquids. Often processes which are normally carried out in a lab are miniaturized on a single chip in order to enhance efficiency and mobility as well as reducing sample and reagent volumes.
It is a multidisciplinary field intersecting engineering, physics, chemistry, microtechnology and biotechnology, with practical applications to the design of systems in which such small volumes of fluids will be used. Microfluidics emerged in the beginning of the 1980s and is used in the development of inkjet printheads, DNA chips, lab-on-a-chip technology, micro-propulsion, and micro-thermal technologies.
How do we define an interposer? Traditionally the chip packaging community defines an interposer as the bridge between the on chip pitch and the on board pitch, i.e the interposer is traditionally the package. With 2.5D or 3D, once again it’s all about the pitch. Chip IO cannot be connected in a stack unless the interfaces have been standardized to match. Thus today’s 2.5D interposer serves as a high density RDL so the chips can be connected either through the interposer. The one criteria true for all of todays 2.5D interposers is that they must contain TSV.
Upon completion, the entire wafer is covered with an insulating layer of glass and silicon nitride to protect it from contamination during assembly. This protective coating is called the passivation layer. The final mask and passivation etch removes the passivation material from the terminals, called bonding pads. The primary inorganic dielectric passivation films are SiO2 and SiN, while polyimides and epoxy resins are used for low-cost polymer encapsulation. Patterns are formed in the passivation-layer material to enable electrical contact to the completed circuit. The area of these contact pads is sufficiently large. Polybenzoxazole (PBO) products are also used as a protective layer or “buffer coat” before packaging or redistribution layer and are well suited to be aligned and exposed with a 1X full field mask aligner.
NxQ has a unique print chamber purge feature and can precisely control outgassing of Polyimides and PBO materials.
High concentrated photovoltaics, or HCPV, concentrate the sun’s irradiation by a factor of 1,100. With a record-breaking efficiency of over 33 percent, HCPV systems have the potential to achieve the lowest power generation costs of any solar technology. Because the cells are so small and powerful, manufacturing a module requires less semiconductor material per watt. The challenge lies in process engineering for the procedure.