Publishing Venue
The IP.com Prior Art Database
Abstract
Disclosed is a method for a split plated through-hole (PTH) structure for enhanced power delivery in multi-power processor systems. Benefits include improved inductance, improved power performance, and improved design flexibility.
Method for a split PTH structure for enhanced power
delivery in multi-power processor systems
Disclosed is a method for a split plated through-hole (PTH)
structure for enhanced power delivery in multi-power processor systems. Benefits include improved inductance, improved power
performance, and improved design flexibility.
Background
� � � � � CPU operation at multiple voltage domains
enables power saving features.
� � � � � The substrate core
lies in the path between the die and the first level of decoupling capacitors
in a typical pin-side cap package. The core is very thick to ensure mechanical
stability. However, the core typically contributes higher inductance and
resistance in the path to the decoupling capacitors and directly impacts their
effectiveness. Higher inductance and resistance increases the voltage
fluctuations at the die bumps, resulting in lower frequency of operation.
� � � � � A CPU that operates
at multiple voltage domains requires a robust power delivery network.
Conventional solutions (see Figure 1) include PTHs arranged in a face-centered
rectangle (FCR) pattern at a pitch that is the minimum possible for the package
technology. This solution provides the lowest possible inductance and
resistance within the scope of the substrate design rules.
� � � � � For CPUs operating at multiple
voltage domains, the conventional method of PTH placement results in higher
perforations decreasing the effectiveness of the power delivery connection
between the package caps and the die.
� � � � � The conventional PTH
can be implemented using the following steps:
1. � � Through-hole drilling
2. � � PTH plating
3. � � PTH plugging/grinding
4. � � Lid plating and
patterning
General description
� � � � � The disclosed method is a split PTH
structure of alternating polarity that replaces the conventional PTHs through a
substrate core.
� � � � � The key elements of the method include:
• � � � � Split PTH structure that alternates with VCC-VSS-VCC-VSS
polarity with respect to the orientation of the neighboring split PTH structure
• � � � � Confinement of current near the sidewalls,
resulting in substantial reduction in skin effect resistance
• � � � � Arrangement of every VSS split
PTH so that they are surrounded by three VCC split PTHs, resulting
in a substantial reduction in...