Publishing Venue
The IP.com Prior Art Database
Abstract
With increased frequency of operation, SoC are facing signal and power integrity issues. To address this issue, on die decaps are used to smoothen the power lines during circuit switching. These decaps occupy precious silicon area. We propose an implementation in which these decaps are implemented off-die using copper plates that are connected to circuitry through insulated copper pillars. These decaps are suitably placed over the switching circuitry so that they are electrically very near to the circuitry.
Off--Chip Parallel Plate Capacitor
using Insulated Cu Pillars
With increased frequency of operation, SoC are facing signal and power
integrity issues. To address this issue, on die decaps are used to smoothen the
power lines during circuit switching. These decaps occupy precious silicon area.
We propose an implementation in which these decaps are implemented off-die
using copper plates that are connected to circuitry through insulated copper
pillars. These decaps are suitably placed over the switching circuitry so that
they are electrically very near to the circuitry.
Fig. 1 shows the architecture of an integrated circuit (die) connected to
off-die decoupling capacitors (decaps) using copper pillars.
Fig 1: Parallel Plate Capacitor Implemented using Cu plates
and connected through insulated Cu pillars
Assembly
The structure can be thought of as a combination of two structures, as
shown in Fig. 2.
Fig 2: Structures forming the assembly
Lithographic Steps to
realize Assembly I
Capacitance Calculations
The laminated metal sheets used as power and ground plate attached to the
die area ~ 10mmx10mm. The lamination is an adhesive with min thickness of 12um
and dielectric constant 5.2.
Fig 3: Parallel
Plate Capacitor
With C= (ɛ0ɛr x A )/d, Ɛ0=8.85x10-12 F/m Ɛr=5.2, A=10x10 mm2 d= 12um
Cdf=0.384 nF
The plates can be stacked to increase the capacitance value.
Fig 4: Stacking of
plates to increase the cap value
Proposal II: Power
Connectivity
Power supplies can be connect...