Semiconductor Package Dummy Substrate Grinding Protection
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Solution Overview
Problem
The grinding process in semiconductor chip manufacturing often results in scratches or cracks on the chips and contamination, leading to reduced yield and quality of semiconductor packages.
Innovation Solution
A semiconductor package design that includes a stack structure with a dummy substrate and a metallic adhesive layer between the substrate and the chip, along with a mold layer on the sidewalls, which helps in heat dissipation and prevents damage during grinding, and a method of fabricating this package that involves forming redistribution lines and external terminals while protecting the chip from contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If grinding is performed on the semiconductor chip, then the chip thickness is reduced, but scratches or cracks occur on the chip and contamination happens
Solution Approach 1:
A dummy substrate is introduced as an intermediary layer between the semiconductor chip and the grinding surface. The dummy substrate absorbs the mechanical stress and contamination during grinding, protecting the actual semiconductor chip from scratches and cracks while enabling thickness reduction
2Productivity
If the semiconductor chip is ground to reduce thickness, then productivity increases, but yield decreases due to damage and contamination
Solution Approach 1:
The dummy substrate is attached to the semiconductor chip before the grinding process begins. This preliminary action prepares the chip for grinding by providing a protective interface, enabling high-speed grinding without the fear of damage, thus increasing productivity while maintaining yield
3Reliability
If a dummy substrate is added to protect the chip, then chip integrity is improved, but device complexity increases
Solution Approach 1:
The dummy substrate serves multiple functions simultaneously: it protects the chip during grinding, provides a stable mounting surface, facilitates heat dissipation, and enables precise thickness control. This multi-functionality justifies the added structural element by delivering multiple benefits from a single component
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 solution effectively increases the yield and quality of semiconductor packages by preventing scratches and cracks on the chips and reducing warpage, while maintaining or improving electrical and mechanical characteristics.
Implementation Method 1
An adhesive layer is disposed on the non-active surface of the semiconductor chip. A dummy substrate is disposed on the adhesive layer
Implementation Method 2
A mold layer is disposed on at least one sidewall of the stack structure
Implementation Method 3
A metallic adhesive layer is disposed between the dummy substrate and the semiconductor chip
Data Source
AI summary
A semiconductor package includes a stack structure, a mold layer disposed on at least one sidewall of the stack structure, a redistribution line electrically connected to the stack structure, and an external terminal electrically connected to the redistribution line. The stack structure includes a semiconductor chip having an active surface and a non-active surface opposite to the active surface. A dummy substrate is disposed on the non-active surface of the semiconductor chip. An adhesive layer is disposed between the dummy substrate and the semiconductor chip. The mold layer includes a top surface adjacent to the redistribution line and a bottom surface opposite to the top surface. The dummy substrate is exposed through the bottom surface of the mold layer.