Backside Layer Prevents Debris Embedding in Semiconductor Dicing
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Solution Overview
Problem
Existing semiconductor die preparation methods face challenges with mechanical sawing, as they often result in silicon debris embedding into the die attach film, leading to electrical interference and requiring additional costly processing steps, and may necessitate wafer expansion, which increases the risk of die attach film un-separation.
Innovation Solution
A method involving the application of a high modulus, electrically insulating backside layer on semiconductor wafers, which acts as a hard barrier to prevent debris embedding and reduces fragment movement, allowing for mechanical sawing without wafer expansion and subsequent packaging without additional processing steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical sawing is used to cut the wafer into dice, then the dicing process can be completed, but silicon debris embeds into the die attach film causing electrical interference
Solution Approach 1:
A backside layer is introduced as an intermediary component between the wafer and the die attach film. This backside layer serves as a protective barrier that prevents silicon debris generated during mechanical sawing from embedding into the die attach film, thereby eliminating electrical interference while maintaining the efficiency of mechanical dicing
Solution Approach 2:
The backside layer is applied to the wafer before the dicing process begins. This preliminary protective measure ensures that when mechanical sawing occurs, the debris is blocked from reaching the die attach film, preventing the harmful effect before it can occur
2Shape
If wafer expansion is performed to separate dice, then dice separation is achieved, but the risk of die attach film un-separation increases
Solution Approach 1:
The backside layer acts as a stabilizing intermediary that distributes mechanical stresses during wafer expansion. By providing a compliant interface between the rigid wafer and the die attach film, it prevents stress concentration that would otherwise cause the die attach film to un-separate
Solution Approach 2:
The backside layer provides beforehand cushioning by absorbing and distributing the mechanical stresses generated during wafer expansion. This protective cushion prevents the die attach film from experiencing excessive stress that would lead to un-separation
3Object-affected harmful factors
If additional processing steps are implemented to remove debris, then electrical interference is reduced, but manufacturing cost increases
Solution Approach 1:
Instead of adding complex removal processes, the backside layer converts the harmful debris generation issue into a manageable problem by providing a sacrificial barrier. The debris embeds into the backside layer instead of the die attach film, and the backside layer can be easily removed afterward, eliminating the need for complex debris removal steps
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 electrical interference, eliminates the need for costly additional processing, and minimizes the risk of die attach film un-separation, enabling a more cost-effective and efficient semiconductor die preparation process.
Implementation Method 1
acts as a hard barrier to prevent debris embedding
Implementation Method 2
layer of an electrically insulating material
Data Source
AI summary
In a described example, a method of forming a semiconductor apparatus includes applying a layer of an electrically insulating material on a backside of a semiconductor wafer having a plurality of integrated circuit dice. The method also includes mounting the wafer to dicing tape with a die attach film, in which the die attach film is between the backside layer and the dicing tape, and cutting the wafer into respective dice.