DC Blocking Capacitors Integrated into IC Package Interconnects
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Solution Overview
Problem
In electronic systems, the large number of DC blocking capacitors required for high-speed serial links on printed circuit boards (PCBs) consumes significant space, increases complexity, and degrades signal integrity due to their placement on the PCB surface, leading to increased wiring lengths and electrical parasitics.
Innovation Solution
Repositioning DC blocking capacitors to the interconnect area between the IC package and the PCB, using custom-shaped capacitors that replace solder balls as interconnect structures, thereby reducing PCB area usage and distances between ICs, and simplifying wiring topologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DC blocking capacitors are placed on the PCB surface, then the circuit can function with DC blocking capability, but the PCB area consumption increases and wiring length increases
Solution Approach 1:
The patent merges the DC blocking capacitor with the interconnect structure between IC package and PCB. The capacitor is integrated into the signal path at the IC package level, combining the interconnect function and DC blocking function into a single integrated structure, thereby eliminating the need for separate PCB-mounted capacitors and reducing PCB area consumption.
Solution Approach 2:
The patent moves the DC blocking capacitor from the traditional PCB surface location to the interconnect area between IC package and PCB. This spatial relocation changes the dimensional arrangement from a distributed PCB layout to a concentrated interconnect-level integration, reducing the signal path length and PCB area required.
2Reliability
If DC blocking capacitors are placed on the PCB surface, then the circuit can function with DC blocking capability, but the wiring length increases and electrical parasitics increase
Solution Approach 1:
The patent merges the DC blocking capacitor with the interconnect structure between IC package and PCB. The capacitor is integrated into the signal path at the IC package level, combining the interconnect function and DC blocking function into a single integrated structure, thereby eliminating the need for separate PCB-mounted capacitors and reducing PCB area consumption.
Solution Approach 2:
The patent moves the DC blocking capacitor from the traditional PCB surface location to the interconnect area between IC package and PCB. This spatial relocation changes the dimensional arrangement from a distributed PCB layout to a concentrated interconnect-level integration, reducing the signal path length and PCB area required.
3Reliability
If a large number of DC blocking capacitors are used for high-speed serial links, then the DC blocking function is achieved, but the device complexity increases
Solution Approach 1:
The patent merges the DC blocking capacitor with the interconnect structure between IC package and PCB. The capacitor is integrated into the signal path at the IC package level, combining the interconnect function and DC blocking function into a single integrated structure, thereby eliminating the need for separate PCB-mounted capacitors and reducing PCB area consumption.
Solution Approach 2:
The patent implements a multi-functional interconnect structure that simultaneously provides mechanical support, electrical connection, and DC blocking capabilities. This universal structure replaces multiple separate components (interconnect element plus capacitor), reducing system complexity while maintaining all required functions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach decreases PCB area usage, reduces signal path discontinuities, and enhances signal integrity by providing consistent interconnect structures for high-speed serial signals, leading to improved data transmission rates and reliability.
Implementation Method 1
A capacitor is a passive electrical component having at least two electrical conductors known as plates, separated by a dielectric or insulator, and which may be used to electrostatically store energy in an electric field
Implementation Method 2
The second set of electrically conductive plates are interleaved with and electrically insulated from the first set of electrically conductive plates by a dielectric material
Data Source
AI summary
A method of attaching an integrated circuit (IC) package to a printed circuit board (PCB) with a set of direct current (DC) blocking capacitors includes: applying a conductive attachment material to a first set of attachment pads located on a first planar surface of the IC package; aligning the set of DC blocking capacitors in accordance with corresponding positions of the first set of attachment pads; attaching the set of DC blocking capacitors to the IC package by: positioning the aligned set of DC blocking capacitors so that a first surface of a first DC blocking capacitor of the set of DC blocking capacitors is adjacent to a corresponding attachment pad of the first set of attachment pads; and connecting the conductive attachment material to the IC package and to the first surface of the first DC blocking capacitor to create an IC package assembly.