Etched Die Singulation to Reduce Defects and Delamination
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Solution Overview
Problem
Existing semiconductor die singulation methods, such as mechanical dicing and laser grooving, often result in defects and delamination issues due to the mechanical stress and heat-induced damage, which can compromise the reliability and strength of the semiconductor packages.
Innovation Solution
A method involving the etching of a die stack to expose a wider top surface of the substrate than necessary for singulation, creating an exposed feature that reduces contact with the metal and oxide layers during the singulation process, thereby minimizing defects and delamination risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical dicing or laser grooving is used for singulation, then the singulation process can be completed, but defects and delamination issues occur due to mechanical stress and heat-induced damage
Solution Approach 1:
The patent replaces mechanical dicing systems with a plasma etching system. The plasma etching process uses reactive ions and radicals to chemically remove material without mechanical contact, eliminating mechanical stress that causes defects and delamination. The plasma process operates at lower temperatures compared to laser grooving, reducing heat-induced damage to the semiconductor structure.
Solution Approach 2:
The patent changes the physical and chemical parameters of the singulation process by using plasma chemistry instead of mechanical force or laser heat. By controlling plasma power, gas flow rates, and etch chemistry, the process achieves clean separation without the harmful effects of mechanical stress or excessive heat, thereby improving reliability and reducing defects.
2Reliability
If the die stack is etched to expose a wider top surface than necessary for singulation, then contact with metal and oxide layers is reduced minimizing defects, but the etching process complexity increases
Solution Approach 1:
The patent applies preliminary patterning and etching actions before the final singulation step. By pre-exposing the die stack to create a wider exposed top surface, the process prepares the structure to minimize contact with metal and oxide layers during subsequent singulation, thereby reducing defects and delamination risks through advance preparation.
Solution Approach 2:
The patent applies different etching conditions to different regions of the die stack. The wider exposed top surface is created with specific etching parameters, while the singulation cut uses different parameters optimized for clean separation. This localized quality control allows the process to reduce defects in critical areas without unnecessarily complicating the entire process.
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 the reliability and strength of semiconductor die by reducing defects and delamination risks, improving the overall performance and longevity of semiconductor packages, especially in applications like iBGA packages.
Implementation Method 1
etching the die stack to expose a top surface of a substrate material of the substrate in the die street
Data Source
AI summary
Implementations of a method of singulating a plurality of die from a substrate may include removing a die stack coupled to a substrate in a die street by etching the die stack to expose a top surface of a substrate material of the substrate in the die street. The first width of the top surface of the substrate material may be exposed. The method also may include forming a plurality of die by singulating, using a kerf width of a second width, the exposed substrate material of the substrate in the die street. The second width may be smaller than the first width.