Semiconductor Package Underfill Dam Formation via Temperature Control
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Solution Overview
Problem
The miniaturization and increased functionality of electronic products lead to high-density mounting of semiconductor devices, causing underfill overflow into peripheral regions, which contaminates electronic devices and circuit patterns, resulting in potential failures and reduced connection reliability.
Innovation Solution
A method of manufacturing semiconductor packages involves forming a dam around the semiconductor chip using a first solution at a lower temperature and filling the gap with underfill using the same solution at a higher temperature, preventing overflow and ensuring reliable connection by controlling the viscosity and temperature of the solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the underfill is sprayed at high temperature to reduce viscosity and improve filling, then the filling efficiency is improved, but the underfill overflows into peripheral regions causing contamination
Solution Approach 1:
The patent changes the temperature parameter of the underfill solution dynamically: first heating to high temperature (e.g., 80-100°C) to reduce viscosity for efficient spraying and filling, then cooling to low temperature (e.g., 20-40°C) to increase viscosity and prevent overflow into peripheral regions. This parameter change resolves the contradiction between filling efficiency and overflow prevention.
Solution Approach 2:
The patent applies preliminary cooling to the underfill solution after filling to increase its viscosity before overflow can occur. By cooling the solution in advance (or immediately after filling), the system prevents the harmful overflow effect before it happens, resolving the contradiction between efficient hot filling and overflow prevention.
2Object-affected harmful factors
If the underfill is sprayed at low temperature to prevent overflow, then contamination is reduced, but the filling efficiency decreases due to high viscosity
Solution Approach 1:
The patent temporarily increases the temperature parameter during the filling phase to reduce viscosity and improve filling efficiency, then decreases the temperature after filling to prevent overflow. This time-dependent parameter change allows the system to achieve both high filling efficiency and overflow prevention at different stages.
Solution Approach 2:
The patent applies periodic temperature control: high temperature during the filling period for efficiency, then low temperature during the stabilization period to prevent overflow. This periodic action resolves the contradiction by applying different temperature conditions at different time periods of the process.
3Manufacturing precision
If different solutions are used for forming the dam and filling the underfill, then the dam formation precision is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent makes the underfill solution multi-functional by using it for both dam formation and gap filling. The same solution serves multiple purposes: it forms the dam structure, fills the gap between chip and substrate, and provides overflow prevention through temperature-controlled viscosity changes. This universality reduces manufacturing complexity while maintaining precision through parameter control.
Solution Approach 2:
The patent achieves different functional outcomes (dam formation vs. gap filling) using the same solution by changing its temperature parameter. During dam formation, the solution is at low temperature for high viscosity and precise structure formation; during gap filling, it is at high temperature for low viscosity and easy flow. This parameter change allows one solution to perform multiple functions with different precision requirements.
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 effectively prevents underfill overflow, reduces failures, and enhances connection reliability by using the same solution for both dam and underfill, simplifying the curing process and reducing manufacturing costs.
Implementation Method 1
a viscosity of the first solution used for forming the dam at the temperature below the set temperature may be higher than a viscosity of the first solution used for filling the region under the semiconductor chip and the region defined by the dam with the underfill at the temperature equal to or higher than the set first temperature
Data Source
AI summary
A method of manufacturing a semiconductor package includes preparing a package substrate including a semiconductor chip mounting region. A semiconductor chip is mounted in the semiconductor chip mounting region. A dam surrounding the semiconductor chip is formed. The formation of the dam includes depositing a first solution having a temperature below a set first temperature. A region under the semiconductor chip and a region defined by the dam are filled with an underfill by depositing the first solution having a temperature equal to or higher than the set first temperature.