Semiconductor Device Wiring Layout for Signal Integrity
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Solution Overview
Problem
In semiconductor devices with multiple chips mounted on a board, achieving high signal integrity is challenging due to the reduced timing margin in double data rate systems, and the use of resistors and power supply components for termination increases size and power consumption.
Innovation Solution
The solution involves optimizing the layout of wiring layers on the mounting board to reduce wiring impedance and crosstalk, eliminating the need for terminating resistors and power supply components by closely placing data and strobe signal wirings, using differential clock signal wirings, and strategically placing power and ground planes to minimize inductance and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If series resistors are added for termination of the transmitting end to match wiring impedance, then signal quality is improved, but packaging area increases and device complexity increases
Solution Approach 1:
The patent removes the series resistors from the transmitting end termination approach, extracting the problematic component that occupied packaging area. Instead, it implements termination resistors only at the receiving end, which eliminates the need for additional components at the transmitting end while maintaining signal quality through proper impedance matching at the receiver side.
Solution Approach 2:
The patent segments the termination function to be performed only at the receiving end rather than at both transmitting and receiving ends. This segmentation allows the system to achieve impedance matching where it is most needed (at the receiver) while avoiding the packaging area consumption and complexity associated with adding components at the transmitting end.
2Reliability
If regulators, inductors and capacitors are mounted for generating terminating power supply at the receiving end, then signal quality is improved, but size of the whole system increases and current consumption increases
Solution Approach 1:
The patent makes the mounting board serve multiple functions: it provides both the termination resistors and the terminating power supply (1/2Vccq) generation capability. By integrating the power supply function into the mounting board rather than requiring separate regulators, inductors and capacitors, the system achieves the needed signal quality improvement while reducing the total number of discrete components.
Solution Approach 2:
The patent merges the termination resistor function and the terminating power supply generation function into a single integrated solution on the mounting board. This combination eliminates the need for separate regulators, inductors and capacitors, thereby reducing component count, system size, and current consumption while maintaining the ability to provide proper termination at the receiving end.
3Reliability
If regulators, inductors and capacitors are mounted for generating terminating power supply, then signal quality is improved, but heat generation increases due to continuous DC current flow
Solution Approach 1:
The patent merges the power supply function into the mounting board's existing structure, eliminating the need for separate regulators and associated components. This integration reduces the continuous DC current flow through separate regulator circuits, thereby reducing heat generation while maintaining the terminating power supply function needed for signal quality.
Data Source
AI summary
A mounting board has a plurality of semiconductor memory devices operated in sync with a clock signal, and a semiconductor data processing device which access-controls the semiconductor memory devices. Layouts of data-system terminals of the semiconductor memory devices with respect to memory access terminals of the semiconductor data processing device are determined in such a manner that wirings for data and a data strobe system (RTdq/dqs) become shorter than wirings for a command/address system (RTcmd/add). The wirings for the data and data strobe system (RTdq/dqs) are laid down using an area defined between the semiconductor memory devices. The wirings for the command/address system (RTcmd/add) bypass the side of the mounting board.