Die Attach Film Singulation for Particle-Free Wafer Dicing
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Solution Overview
Problem
The presence of silicon particles from incomplete die attach film separation during singulation processes in chip on lead (COL) devices leads to shorts or leakage between the lead and the attached die, causing manufacturing defects and increased costs due to inefficient etch processing.
Innovation Solution
A method involving controlled singulation of non-conductive die attach film and semiconductor dies from a wafer, ensuring a non-zero gap distance between the semiconductor die and the end of the die attach film, using a combination of blade, laser, and plasma dicing techniques to minimize silicon particle formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a die attach film singulation process is performed to separate die attach film portions, then the die attach film can be isolated from the die, but silicon particles are generated that cause shorts or leakage between the lead and the die
Solution Approach 1:
The die attach film is singulated separately from the die in a first singulation process before the die is singulated in a second process. This preliminary separation prevents silicon particles from being generated during the die attach film cutting operation, as the film is already isolated from the die substrate before dicing occurs.
Solution Approach 2:
The singulation process is divided into two distinct segments: first singulating the die attach film from the die, then singulating the die from the wafer. This segmentation allows each process to be optimized independently, preventing cross-contamination and silicon particle generation that would occur if both were singulated together in a single process.
2Object-generated harmful factors
If etch processing is used to remove silicon particles, then particle contamination can be reduced, but manufacturing costs increase and productivity decreases
Solution Approach 1:
Instead of using costly etch processing to remove harmful silicon particles, the invention converts the potential harm into a benefit by designing a process that prevents particle generation in the first place. The separate singulation approach ensures that no silicon particles are generated during die attach film processing, eliminating the need for subsequent particle removal steps.
Solution Approach 2:
The problematic interaction between the die attach film and the die during singulation is extracted and eliminated by performing the film singulation separately. This removes the source of silicon particle generation from the process, making etch processing unnecessary and improving both cost efficiency and productivity.
3Device complexity
If the die attach film is singulated together with the die, then the process is simpler, but incomplete separation occurs leading to manufacturing defects
Solution Approach 1:
The singulation process is segmented into two independent operations: first singulating the die attach film from the die, then singulating the die from the wafer. This segmentation ensures complete separation of each component without interference, achieving high manufacturing precision while maintaining reasonable process complexity through systematic division of steps.
Solution Approach 2:
The die attach film is singulated in advance before the die singulation step. This preliminary action ensures that the film is completely separated and isolated before the die dicing process, preventing any incomplete separation defects while allowing each process to be optimized for its specific 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 reduces silicon particle-related defects, enhances electrical isolation, and lowers manufacturing costs by improving process yield and productivity in electronic device packaging.
Implementation Method 1
performing a first singulation process that separates portions of a die attach film on a wafer, performing a second singulation process that separates a semiconductor die from the wafer
Implementation Method 2
using a combination of blade, laser, and plasma dicing techniques to minimize silicon particle formation
Implementation Method 3
using a combination of blade, laser, and plasma dicing techniques to minimize silicon particle formation
Data Source
AI summary
An electronic device includes a conductive lead, a semiconductor die, a package structure enclosing the semiconductor die and a portion of the conductive lead, and a non-conductive die attach film extending between the conductive lead and the semiconductor die, with a lateral side of the semiconductor die extending beyond an end of the die attach film by a non-zero gap distance. A method of fabricating an electronic device includes performing a first singulation process that separates portions of a die attach film on a wafer, performing a second singulation process that separates a semiconductor die from the wafer having a portion of the die attach film, and attaching the semiconductor die to a lead frame with the die attach film extending between a prospective lead portion and the side of the semiconductor die.