Semiconductor Package Bump Formation Without Laser Ablation Damage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Double Side Molding (DSM) technology for semiconductor devices results in low reliability due to damage and abnormal shape of conductive bumps during the laser ablation process, leading to solder bridges and incomplete external interconnect structures.
Innovation Solution
A method using a laser soldering technique to form a second conductive bump on exposed portions of the first conductive bump, allowing precise control of height and avoiding shape-dependent issues, thus enhancing the reliability of semiconductor devices by preventing solder bridges and ensuring complete interconnect formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional laser ablation process is used to form conductive bumps, then manufacturing process is simple, but reliability is low due to damage and abnormal shape of conductive bumps
Solution Approach 1:
The patent replaces the conventional mechanical laser ablation process with a laser soldering process. Instead of using laser ablation to remove material and form conductive bumps, the invention uses laser energy to melt and solidify solder material, forming precise conductive bumps and interconnect structures. This substitution eliminates the damage and shape abnormalities caused by ablation while maintaining manufacturing simplicity.
Solution Approach 2:
The patent changes the fundamental process parameters from ablation (removal) to soldering (deposition and melting). By controlling laser power, duration, and material composition, the process achieves precise control over conductive bump formation, eliminating shape abnormalities and improving reliability without sacrificing manufacturing efficiency.
2Reliability
If conventional DSM technology is used, then package size is reduced, but reliability is low due to solder bridges and incomplete interconnect structures
Solution Approach 1:
The patent replaces conventional molding and ablation processes with laser soldering to form interconnect structures. This enables precise control over solder material placement and melting, eliminating solder bridges and incomplete interconnect formations while maintaining the compact package design enabled by DSM technology.
Solution Approach 2:
By changing from ablation-based to soldering-based processes, the patent achieves precise control over interconnect structure formation. The laser soldering process parameters (power, duration, material feed rate) are optimized to ensure complete and accurate interconnect formation without creating defects, thereby improving reliability within the compact package volume.
3Ease of manufacture
If laser ablation is used to expose conductive bumps, then groove formation is simple, but conductive bumps are damaged and take abnormal shapes
Solution Approach 1:
The patent replaces laser ablation with laser soldering for groove formation and conductive bump creation. The laser energy is used to melt and solidify solder material directly in the desired groove locations, forming precise conductive bumps without the damage and shape abnormalities caused by ablation. This maintains manufacturing simplicity while dramatically improving shape accuracy.
Solution Approach 2:
The patent changes the process from material removal (ablation) to material deposition and melting (soldering). By controlling laser parameters and solder material properties, the process achieves precise groove formation and conductive bump shaping without damaging the underlying conductive structures, resolving the contradiction between ease of manufacture and shape accuracy.
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 method improves the reliability of semiconductor devices by accurately forming fine-pitch ball arrays and reducing package size, while avoiding solder bridges and ensuring uniform interconnect structures, thereby enhancing the overall performance and reliability of the semiconductor package.
Implementation Method 1
forming a second conductive bump on the exposed portion of the first conductive bump using a laser soldering apparatus
Implementation Method 2
forming a groove in the first encapsulant to expose at least a portion of the first conductive bump
Data Source
AI summary
A semiconductor device and a method for forming the same are provided. The method includes: providing a package including: a substrate including a first substrate surface and a second substrate surface opposite to the first substrate surface; a first conductive bump formed on the first substrate surface; and a first encapsulant disposed on the first substrate surface and encapsulating the first conductive bump; forming a groove in the first encapsulant to expose at least a portion of the first conductive bump; and forming a second conductive bump on the exposed portion of the first conductive bump using a laser soldering apparatus.