Direct Chip Attach Circuit Board with Segmented Interconnect Zones
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Solution Overview
Problem
Current IC chip packaging and motherboard mounting technologies face challenges such as increased Z-height, higher costs, reduced manufacturing rates, and specialized equipment requirements, particularly when trying to accommodate smaller die sizes and higher interconnect densities in devices like smartphones and tablets.
Innovation Solution
The proposed solution involves a direct chip attach (DCA) method where the IC chip is mounted directly onto the motherboard without a packaging substrate, using a breakout area with finer pitch interconnects and laser scribing processes to create aggressive design rule-compatible zones, allowing for a transition from chip-level to motherboard-level interconnect pitches without scaling the entire motherboard technology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single HDI substrate is used for interconnect scaling, then die routing capability is improved, but substrate body size increases and manufacturing complexity increases
Solution Approach 1:
The circuit board is divided into a first interconnect zone with finer pitch contacts for die routing and a second interconnect zone with larger pitch contacts for system board interfacing. This segmentation allows different pitch requirements to be satisfied in different regions without requiring the entire substrate to accommodate the finest pitch, thereby reducing overall substrate size while maintaining die routing capability.
Solution Approach 2:
The circuit board implements local quality by providing different contact pitches in different zones: the first interconnect zone has finer pitch contacts optimized for die routing, while the second interconnect zone has larger pitch contacts optimized for system board interfacing. This localized optimization allows each zone to perform its specific function efficiently without compromising the other.
2Reliability
If current IC chip packaging is used, then electrical connections are enabled, but Z-height increases and manufacturing rate decreases
Solution Approach 1:
The patent extracts the packaging substrate from the traditional IC chip assembly, enabling direct attachment of the die to the circuit board. By removing the intermediate packaging layer, the Z-height is reduced and manufacturing steps are simplified, improving production rate while maintaining electrical connection reliability through direct die-to-board bonding.
3Area of moving object
If smaller die sizes are used, then device footprint is reduced, but interconnect density requirements increase
Solution Approach 1:
The patent addresses the interconnect density challenge by transitioning to a three-dimensional stacked architecture with multiple interconnect zones at different vertical levels. The first interconnect zone handles fine-pitch connections to the smaller die, while the second interconnect zone provides larger pitch connections to the system board, allowing small die footprint to be maintained while satisfying high interconnect density requirements through vertical dimension utilization.
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 reduces Z-height, decreases costs, increases manufacturing efficiency, and eliminates the need for specialized equipment, providing a cost-effective solution for attaching IC chips to motherboards in devices like smartphones and tablets while maintaining or improving signal routing capabilities.
Implementation Method 1
laser scribing processes to create aggressive design rule-compatible zones
Data Source
AI summary
A circuit board upon which to mount an integrated circuit chip may include a first interconnect zone on the surface of the circuit board having first contacts with a first pitch, and a second interconnect zone, surrounding the first zone, having second contacts or traces with a second pitch that is smaller than the first pitch. The first contacts may have a design rule (DR) for direct chip attachment (DCA) to an integrated circuit chip. The first contacts may be formed by bonding a sacrificial substrate having the first contacts to a surface of the board; or by laser scribing trenches where the conductor will be plated to create the first contacts. Such a board allows DCA of smaller footprint processor chips for devices, such as tablet computers, cell phones, smart phones, and value phone devices.