Flip Chip Substrate Bump Ring for Thermal Strain Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing integrated circuit packages face challenges in achieving high performance, compactness, reliability, low cost, and simplified manufacturing while addressing heat-related issues in flip chip designs, as traditional methods to increase gap height compromise on cost, simplicity, and structural integrity.
Innovation Solution
The implementation of a substrate with a bump ring having an inner cavity area and an outer bump area, where a substrate mask layer is applied adjacent to the perimeter of the outer bump area, increasing the gap height without complex fabrication, and applying a compound between the device and the substrate to minimize thermal strain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If larger connectors are used to raise the flip chip higher away from the substrate to increase gap height, then more compound material can be applied to improve heat management, but cost increases and height dimensions are compromised
Solution Approach 1:
The substrate is segmented into different regions: a first region with a first thickness and a second region with a second thickness greater than the first thickness. This segmentation allows the substrate itself to provide the height variation needed for increased gap height in specific areas without requiring larger connectors throughout the entire package.
Solution Approach 2:
Instead of increasing gap height uniformly across the entire substrate or using larger connectors, the invention introduces thickness variation in the substrate's vertical dimension at specific locations. This localized thickness change creates the necessary gap height increase only where needed, avoiding the need for larger connectors while maintaining cost-effectiveness and compact dimensions.
2Reliability
If larger connectors are used to increase gap height, then more compound material can be applied, but manufacturing complexity and cost increase
Solution Approach 1:
The substrate is divided into regions of different thicknesses, allowing localized gap height increase without requiring changes to the connectors or complex fabrication processes. This segmentation can be achieved through standard substrate manufacturing techniques, avoiding the need for specially designed substrates with complex fabrication.
Solution Approach 2:
The substrate structure itself provides the gap height increase function through its varied thickness design, eliminating the need for additional components or complex assembly steps. The substrate serves multiple functions: providing mechanical support, electrical connections, and the height variation needed for compound material application.
3Reliability
If specially designed substrates are used to increase gap height, then heat management improves, but structural integrity is compromised
Solution Approach 1:
The substrate has different thicknesses in different regions: a first thickness in the first region and a greater second thickness in the second region. This local quality variation allows the substrate to provide increased gap height and improved heat management in specific areas while maintaining adequate structural integrity in other areas. The thicker second region provides the necessary height for compound material application, while the overall substrate structure remains robust.
4Reliability
If sufficient compound material is applied to fill gap areas, then heat related problems are avoided, but gap height must be increased
Solution Approach 1:
The substrate is segmented into regions of different thicknesses, creating localized areas of increased gap height. This allows sufficient compound material to be applied in specific regions where heat management is critical, without requiring a uniform increase in gap height across the entire package.
Solution Approach 2:
The invention addresses the gap height requirement by varying the substrate thickness in the vertical dimension at specific locations rather than increasing the overall gap height uniformly. This allows sufficient compound material application for heat management while maintaining a compact overall package height.
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 enhances thermal management, reduces manufacturing costs, and maintains the advantages of compactness and reliability, while avoiding the need for small filler particle sizes and minimizing voids in the compound, thus providing a cost-effective and efficient solution for high-performance integrated circuit packages.
Implementation Method 1
The compound material is applied between the active surface of the flip chip and the substrate... The compound fills gaps between and around the connectors and fills areas between the flip chip and the substrate... A key to solving heat related issues of the flip chip is the application of a compound material such as a thermally conductive epoxy
Data Source
AI summary
An integrated circuit package system includes: providing a substrate having a top side with a trace conductor connected to a bottom side with a system interconnect; forming a bump ring on the substrate, the bump ring having an inner cavity area over the trace conductor and an outer bump area; applying a substrate mask layer adjacent a perimeter of the outer bump area; connecting a device to the trace conductor below the bump ring; and applying a compound between the device and the substrate.