Staggered Flip-Chip Bump Layout for Dense Signal Routing
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Solution Overview
Problem
The increasing number of bumps in IC chips for flip chip bonding, particularly in display driver ICs, poses challenges in the placement and routing of bumps, bond pads, and routing traces, due to the need for interfacing a large number of signals.
Innovation Solution
The implementation of a staggered bump arrangement with multiple rows of bumps, where corresponding bumps in adjacent rows are offset, allows for more efficient placement of routing traces by reducing the area required for the bump array and relaxing constraints on routing trace width and pitch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of bumps is increased to interface a large number of signals, then the signal interfacing capability is improved, but the difficulty of placement and routing of bumps, bond pads, and routing traces increases
Solution Approach 1:
The bump array is segmented into multiple rows with corresponding bumps in adjacent rows offset from each other. This segmentation allows routing traces to pass through the spaces between offset bumps, reducing routing difficulty while maintaining a large number of signal interfaces.
Solution Approach 2:
The invention transitions from a single-row bump arrangement to a multi-row staggered arrangement, utilizing the two-dimensional space more efficiently. By offsetting bumps in adjacent rows, the design creates additional routing pathways in the spatial dimension, reducing the complexity of placing and routing traces among a large number of bumps.
2Quantity of substance
If the number of bump rows is increased, then the signal interfacing capability is improved, but the constraints on routing trace width and pitch become more stringent
Solution Approach 1:
By segmenting the bump array into multiple offset rows, the invention creates larger effective pitch between corresponding bumps in different rows. This relaxed pitch allows routing traces to be wider and more easily manufactured, even when a large total number of bump rows is used to interface many signals.
Solution Approach 2:
The staggered arrangement creates locally varied spacing patterns where routing traces can utilize the offset spaces between bumps. This local quality variation allows for optimized trace width and pitch in different regions, reducing overall manufacturing precision constraints while accommodating a large number of bump rows.
Data Source
AI summary
An integrated circuit includes a semiconductor chip, a first bump row, and a second bump row. The semiconductor chip has a first edge oriented in a first planar direction. The first bump row includes a plurality of first bumps aligned in the first planar direction along the first edge, and the second bump row includes a plurality of second bumps aligned in the first planar direction. The second bump row is located farther from the first edge of the semiconductor chip than the first bump row. A first width of the first bumps in the first planar direction is narrower than a second width of the second bumps in the first planar direction.