or the voltage regulator to respond, decoupling capacitors provide additional power to the die. Voltage regulators located on the PCB often have response times in the microsecond range. Thus, large decoupling capacitors are placed on the packaging substrate to compensate for slow response times. The large decoupling capacitors occupy a large area. One conventional arrangement includes a bulk capacitor of microFarads and a multi-layer chip capacitor (MLCC) having hundreds of nanoFarads along with the voltage regulator on the PCB. The combination of the bulk capacitor and the MLCC supplies voltage to the die while the voltage regulator responds to the current transient.
Attempts have been made to place voltage regulators on the dies. However, voltage regulators include passive components such as inductors and capacitors that are also embedded in the dies. Passive devices consume die area, which increases manufacturing cost. For example, a die manufactured using 45 nm technology has a capacitance density of 10 femtoFarads/m2. At this density a suitable amount of capacitance may consume over 2.5 mm2. Providing inductance to the voltage regulator conventionally uses an on-die inductor or a discrete inductor mounted on the packaging substrate. In addition to consuming large areas on a die, conventional on-die inductors have a low quality factor.
A quality factor for passive components embedded in a die is low because the passive components are manufactured thin to fit in the die. As the amount of conducting material shrinks, conductive or magnetic losses increase and degrade the quality factor. The quality factor is defined by the energy stored in a passive component versus energy dissipated in the passive component, for a passive component embedded in a die is low.
Thus, there is a need for a voltage regulator that is in close proximity to the die without consuming large amounts of die area.
According to one aspect of the disclosure, a voltage regulator has a passive portion at least partially embedded in a packaging substrate. The voltage regulator also has an an active portion fabricated in a die coupled to the passive portion.
According to another aspect of the disclosure, a method of supplying voltage to a die mounted on a packaging substrate includes mounting an active portion of a voltage regulator on the packaging substrate. The method also includes coupling the active portion of the voltage regulator to at least one passive component at least partially embedded in the packaging substrate. The method further includes coupling the die to the at least one passive component.
According to yet another aspect of the disclosure, a method of supplying power to a die includes providing a supply voltage to an active portion of a voltage regulator mounted on a packaging substrate mounted on a printed circuit board. The method also includes passing the supply voltage from the active portion of the voltage regulator to at least one inductor at least partially embedded in the packaging substrate. The method further includes passing the supply voltage from the at least one inductor to at least one capacitor at least partially embedded in the packaging substrate. The method also includes passing the supply voltage from the at least one capacitor to the die.
According to a further aspect of the disclosure, a semiconductor packaging system includes a packaging substrate into which at least one means for storing energy is at least partially embedded. The semiconductor packaging system also includes means for regulating voltage mounted on the packaging substrate. The regulating voltage means cooperating with the energy storing means.
The foregoing has outlined rather broadly the features and technical advantages of the present disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed