Laser Direct Ablation for RDL Trenches in Insulating Layers
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Solution Overview
Problem
Conventional semiconductor manufacturing processes face challenges in achieving smaller semiconductor devices with high mechanical properties in insulating layers for redistribution layers (RDL) due to the complexity and cost associated with photolithography, and the need for insulating layers with specific tensile strength and elongation properties.
Innovation Solution
The formation of semiconductor devices involves a first and second laser direct ablation (LDA) process to create openings and RDL trenches in insulating layers, allowing for the deposition of conductive layers within these trenches, resulting in insulating layers with enhanced mechanical properties such as tensile strength and elongation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography process is used to remove portions of insulating layers, then openings and trenches can be formed, but the manufacturing cost and complexity increase
Solution Approach 1:
The patent replaces the photolithography process (which requires photoresist coating, patterning, and development steps) with a mechanical drilling process. Drill bits are used to directly form openings and trenches through the insulating layers, eliminating the need for photoresist materials and associated processing equipment, thereby reducing manufacturing complexity while maintaining precision
Solution Approach 2:
The patent extracts and removes the photoresist layer from the manufacturing process entirely. By using mechanical drilling to create openings and trenches directly in the insulating layers, the process eliminates the photoresist coating, patterning, and development steps that are inherent to photolithography, simplifying the overall manufacturing workflow
2Manufacturing precision
If photolithography process is used to remove portions of insulating layers, then openings and trenches can be formed, but the manufacturing cost increases
Solution Approach 1:
The patent substitutes expensive photolithography equipment and materials with simpler mechanical drilling equipment. The drill bits directly create openings and trenches without requiring photoresist materials, photoaligners, or complex patterning equipment, significantly reducing capital equipment costs and material costs while maintaining the ability to form precise openings and trenches
Solution Approach 2:
The patent employs disposable drill bits that are inexpensive compared to photoresist materials and photolithography equipment. These drill bits can be replaced as needed without requiring expensive equipment investment, making the manufacturing process more cost-effective while achieving the required precision for opening and trench formation
3Ease of manufacture
If insulating layer tensile strength and elongation are reduced for photolithography compatibility, then photolithography can be used, but the mechanical properties of the insulating layer deteriorate
Solution Approach 1:
Instead of modifying the insulating layer properties to suit photolithography requirements, the patent inverts the approach by selecting insulating layers with optimal mechanical properties (high tensile strength and elongation) and using a mechanical drilling process that is compatible with these enhanced properties, thereby improving mechanical strength while maintaining manufacturability
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 enables the production of semiconductor devices with improved mechanical properties in the insulating layers, facilitating the formation of smaller, more efficient RDLs, which reduces manufacturing complexity and cost while maintaining the necessary mechanical integrity.
Implementation Method 1
a first laser direct ablation (LDA) process to create openings and RDL trenches in insulating layers
Data Source
AI summary
A semiconductor device has a semiconductor die with an encapsulant deposited over the semiconductor die. A first insulating layer having high tensile strength and elongation is formed over the semiconductor die and encapsulant. A first portion of the first insulating layer is removed by a first laser direct ablation to form a plurality of openings in the first insulating layer. The openings extend partially through the first insulating layer or into the encapsulant. A second portion of the first insulating layer is removed by a second laser direct ablation to form a plurality of trenches in the first insulating layer. A conductive layer is formed in the openings and trenches of the first insulating layer. A second insulating layer is formed over the conductive layer. A portion of the second insulating layer is removed by a third laser direct ablation. Bumps are formed over the conductive layer.