Semiconductor Package Carrier With Dam Spacing For Heat Dissipation
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Solution Overview
Problem
Conventional semiconductor packaging methods face challenges such as high yield loss due to delicate wafer handling, thermal hot spots, and the need for expensive equipment, particularly in achieving high thermal performance and low production costs for miniaturized, stacked packages.
Innovation Solution
A chip package design featuring a carrier with a support structure that creates convection paths for heat dissipation by providing spacing between the dam and the chip or chip stack, allowing for efficient thermal management without requiring extensive reflow or expensive equipment, using a carrier with contact pads and a dam to secure and dissipate heat from stacked chips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional wafer-to-wafer or chip-to-wafer stacking is used to achieve 3D packages, then high memory density and shorter electrical connections are achieved, but repeated handling of thin wafers causes cracking and high yield loss
Solution Approach 1:
A carrier substrate is introduced as an intermediary component to hold multiple chips in a stacked configuration. The carrier substrate provides mechanical support and alignment features, eliminating the need for direct handling of thin wafers during stacking operations. This mediator approach allows precise stacking without causing wafer cracking or damage.
2Reliability
If multiple reflow cycles are performed for stacked packages, then proper bonding is achieved, but thermal hot spots are generated that affect device functionality
Solution Approach 1:
The reflow process is extracted from the stacking operation itself and performed separately on individual chips before mounting. By pre-bumping chips with solder balls and then mounting them cold onto the carrier, the patent eliminates the need for multiple reflow cycles during stacking, thereby avoiding thermal hot spots while maintaining bonding quality through the pre-formed solder joints.
3Manufacturing precision
If wafer-to-wafer or chip-to-wafer stacking equipment is used, then high precision stacking is achieved, but expensive equipment is required
Solution Approach 1:
The stacking process is segmented into separate operations: chip preparation with bumps is done individually, then chips are mounted onto the carrier using standard pick-and-place equipment. The carrier substrate includes alignment features and recesses that enable precise positioning without requiring expensive specialized stacking equipment. This segmentation approach achieves high precision using conventional assembly tools.
4Volume of moving object
If chips are stacked closely together to maximize density, then space is optimized, but heat dissipation becomes difficult
Solution Approach 1:
The carrier substrate is designed with localized thermal management features including heat sinks positioned at specific locations beneath or adjacent to chip stacks. These heat sinks provide targeted thermal pathways that conduct heat away from high-density chip regions without requiring increased spacing between chips. The local quality approach maintains high density while addressing thermal issues through strategically placed thermal management structures.
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
The solution enhances thermal performance and reduces production costs by minimizing thermal challenges and handling-related issues, enabling robust and efficient heat dissipation in stacked semiconductor packages while maintaining compatibility with existing assembly equipment.
Implementation Method 1
The spacing creates convection paths to dissipate heat
Data Source
AI summary
A chip package includes a carrier having a first and a second major surface. The first major surface includes an active region surrounded by an inactive region. The chip package includes contact pads in the active region for mating with chip contacts of a chip. A support structure is disposed on the inactive region of the first major surface. The support structure forms a dam that surrounds the active region. When a chip or chip stack is mounted in the active region, spacing exists between the dam and the chip or chip stack. The spacing creates convention paths for heat dissipation.