Semiconductor Package Dummy Solder for Signal Interference Reduction
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Solution Overview
Problem
As semiconductor integrated circuits become denser and highly integrated, there is a growing need for more reliable and simpler flip chip bonding methods to manage the increasing number of pin connections and narrow electrode terminals in semiconductor packages, while maintaining reliable electrical connections without signal interference or electrical shorts.
Innovation Solution
The semiconductor package design includes a circuit substrate with exposed substrate connection terminals and insulation layers that feature dummy openings for non-electrical dummy solder, which does not connect the semiconductor chip to the substrate, allowing for the formation of inner solder balls between chip and substrate terminals while preventing electrical shorts and reducing signal interference by keeping dummy solder away from the chip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dummy solder is used to fill openings in insulation layers, then manufacturing reliability is improved by preventing electrical shorts, but signal interference may occur if dummy solder is positioned too close to chip terminals
Solution Approach 1:
The patent divides the solder structure into two distinct segments: inner solder balls that form actual electrical connections between chip terminals and substrate, and dummy solder that fills openings in insulation layers without contacting terminals. This segmentation allows dummy solder to provide manufacturing reliability (preventing shorts during assembly) while being spatially separated from chip terminals to avoid signal interference.
Solution Approach 2:
The patent applies local quality by creating different functional zones: areas with inner solder balls for electrical connection and areas with dummy solder for structural support and short prevention. The dummy solder is strategically positioned in openings of substrate or chip insulation layers away from terminal regions, providing local reliability enhancement without creating harmful electromagnetic interference in sensitive terminal areas.
2Adaptability or versatility
If the number of pin connections and electrode terminals is increased to meet higher integration demands, then device functionality is improved, but manufacturing complexity and risk of electrical shorts increase
Solution Approach 1:
The patent implements preliminary action by forming dummy solder structures in openings of insulation layers before final chip assembly. This pre-positioned dummy solder prevents electrical shorts during the bonding process and eliminates the need for complex post-assembly adjustments or inspections, thereby supporting higher integration without proportionally increasing manufacturing complexity.
3Reliability
If inner solder balls are formed to connect chip terminals to substrate, then electrical connection reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies self-service through self-aligned solder ball formation where inner solder balls automatically position themselves during the bonding process. The solder material flows and solidifies in a self-regulating manner, utilizing the thermal and mechanical conditions of the bonding process itself to achieve precise positioning without requiring external alignment mechanisms or highly precise pre-positioning, thereby reducing manufacturing precision requirements while maintaining connection reliability.
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 design ensures reliable electrical connections between semiconductor chips and substrates, reduces signal interference, and prevents electrical shorts, thereby enhancing the reliability of semiconductor packages without altering existing signal wiring designs.
Implementation Method 1
An inner solder ball is between the substrate connection terminal and the chip connection terminal. The inner solder ball electrically connects the substrate connection terminal to the chip connection terminal.
Implementation Method 2
A dummy solder fills a dummy opening in at least one of the substrate insulation layer and the chip insulation layer. The dummy solder does not electrically connect the semiconductor chip with the substrate.
Data Source
AI summary
A semiconductor package includes a circuit substrate, a semiconductor chip on the circuit substrate, an inner solder ball between the circuit substrate and the semiconductor chip, and dummy solder filling a dummy opening in at least one of an substrate insulation layer of the circuit substrate and a chip insulation layer. The dummy solder does not electrically connect the semiconductor chip with the substrate. The circuit substrate may include a base substrate, a substrate connection terminal on the base substrate, and the substrate insulation layer covering the base substrate. The semiconductor chip may include a chip connection terminal and the chip insulation layer exposing the chip connection terminal. The inner solder ball may be interposed between the substrate connection terminal and the chip connection terminal to electrically connect the circuit substrate to the semiconductor chip.