Supporting Glass Substrate for Dimensional Stability in Fan-Out Packaging
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Solution Overview
Problem
The existing methods for manufacturing fan-out type wafer level packages face challenges in maintaining high-density wiring and accurate solder bump formation due to dimensional changes in the processed substrate during heat treatment, which can lead to deformation and chipping of semiconductor chips.
Innovation Solution
A supporting glass substrate with a polished surface and controlled total thickness variation of less than 5.0 μm is used to support the processed substrate, enhancing processing accuracy and preventing deformation, while its high Young's modulus and low warpage level ensure stability and ease of handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heat treatment is performed at about 200°C during the manufacturing process, then the semiconductor chips can be molded and wired, but the sealing material may be deformed and the processed substrate may change in dimension
Solution Approach 1:
A supporting substrate is introduced as an intermediary component between the processed substrate and the manufacturing environment. This supporting substrate has superior thermal stability and dimensional rigidity, acting as a mediator that prevents the processed substrate from deforming during heat treatment. The supporting substrate absorbs thermal expansion stresses and maintains the geometric integrity of the processed substrate throughout the manufacturing process.
Solution Approach 2:
The invention changes the physical parameters of the support system by transitioning from a conventional supporting substrate to one with specifically controlled thermal expansion coefficient and mechanical properties. The supporting substrate is designed with parameters that match or exceed the processed substrate's thermal and mechanical characteristics, enabling it to withstand heat treatment temperatures without transmitting deformation to the processed substrate.
2Temperature
If the processed substrate changes in dimension, then heat treatment can be performed, but it becomes difficult to arrange wiring at high density and form solder bumps accurately
Solution Approach 1:
The supporting substrate serves as a stable intermediary platform that decouples the heat treatment process from the processed substrate. While the supporting substrate undergoes thermal expansion during heat treatment, its superior mechanical properties and larger size prevent this expansion from translating into dimensional changes of the processed substrate, thereby maintaining wiring and solder bump precision.
Solution Approach 2:
The supporting substrate provides beforehand cushioning against thermal deformation by being pre-designed with sufficient mechanical strength and thermal stability. This cushioning effect is built into the support structure before heat treatment begins, preventing dimensional changes in the processed substrate that would otherwise occur during temperature cycling.
3Reliability
If a conventional supporting substrate is used, then the processed substrate can be supported, but it may still be difficult to arrange wiring at high density on one surface
Solution Approach 1:
The invention optimizes the parameters of the supporting substrate, specifically its thickness, material composition, and mechanical properties, to enhance its ability to maintain the processed substrate's dimensional stability. By carefully selecting and controlling these parameters, the supporting substrate provides sufficient support while enabling high-density wiring arrangement on the processed substrate surface.
Data Source
AI summary
Devised are a supporting substrate capable of contributing to an increase in density of a semiconductor package and a laminate using the supporting substrate. A supporting glass substrate of the present invention includes a polished surface on a surface thereof and has a total thickness variation of less than 2.0 μm.