Through Wiring Substrate Polishing Depth Control
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Solution Overview
Problem
The existing methods for manufacturing through wiring substrates face challenges such as uneven polishing, plastic deformation, and gaps between through wirings and inner walls, leading to variations in film thickness, membrane stress, and electrical connection degradation, which complicate the integration of elements and pattern manufacturing.
Innovation Solution
A method involving the formation of through holes in a substrate, filling them with conductive material, and polishing to ensure that the end faces of through wirings on one surface are smaller in depth than those on the opposing surface, using a single type of conductive material to reduce deformation and enhance uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the conductive material is polished to planarize the substrate surface, then the surface flatness is improved, but gaps arise between the through wirings and the inner walls of the through holes due to plastic deformation
Solution Approach 1:
The patent changes the physical-chemical parameters of the conductive material by controlling the plating conditions to achieve uniform plating thickness and minimize protruding height variations. This reduces the amount of polishing required and consequently reduces plastic deformation at the end faces, maintaining both surface flatness and electrical connection reliability
Solution Approach 2:
The patent performs preliminary actions during the plating process to pre-compensate for potential polishing-induced deformation. By controlling the plating uniformity and protruding height in advance, the subsequent polishing process causes minimal plastic deformation, preventing gap formation between through wirings and through hole inner walls
2Reliability
If the protruding height of the conductive material is increased to ensure sufficient through wiring formation, then the electrical connection is improved, but the polishing time increases and uneven polishing occurs
Solution Approach 1:
The patent optimizes plating parameters such as current density, plating time, and solution composition to achieve uniform conductive material deposition with controlled protruding height. This uniformity reduces the total polishing time required while maintaining sufficient through wiring formation for reliable electrical connection
Solution Approach 2:
The patent replaces prolonged mechanical polishing with a more efficient process by achieving near-final dimensions through controlled plating. The reduced protruding height variation minimizes the mechanical polishing required, substituting time-consuming mechanical removal with precision chemical deposition
3Manufacturing precision
If the end faces of through wirings are concaved deeply to remove protruding portions, then the surface uniformity is improved, but the film thickness uniformity of thin films degrades and membrane stress increases
Solution Approach 1:
The patent controls plating parameters to minimize protruding height variation across the substrate surface. This reduces the depth of concavation needed during polishing, preventing excessive removal of material that would cause film thickness non-uniformity and membrane stress in subsequently deposited thin films
Solution Approach 2:
The patent performs preliminary plating with controlled uniformity to pre-establish a foundation that requires minimal subsequent material removal. This preliminary action prevents the need for deep concavation that would compromise thin film quality and cause membrane stress
4Manufacturing precision
If different materials are used for the main portion and contact portions of through wirings to reduce polishing gaps, then the manufacturing precision is improved, but the device complexity increases due to multiple plating processes
Solution Approach 1:
The patent uses homogeneous material composition throughout the through wiring structure, eliminating the need for multi-material construction. By achieving uniform plating with minimal protruding height variation, the patent reduces polishing gaps without requiring complex multi-step plating processes with different materials
Solution Approach 2:
The patent merges the functions of main portion and contact portions into a single homogeneous conductive material structure. This consolidation eliminates the complexity of coordinating multiple plating processes while achieving the same gap-reduction effect through improved plating uniformity control
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 results in a substrate with uniform film thickness and reduced membrane stress near through wirings, enabling high electrical reliability and simplified manufacturing of minute patterns with fewer processing steps.
Implementation Method 1
Methods for filling through holes with a conductive material include the electroplating method
Implementation Method 2
The conductive material protruding from both ends of the through holes is polished to be planarized
Data Source
AI summary
The present invention offers a device requiring a reduced number of manufacturing processes and providing high electrical reliability, and a method for manufacturing the device. The method for manufacturing the device forms through holes in a substrate, fills the through holes with a conductive material through electroplating from a first surface side of the substrate, polishes the conductive material to form through wirings, and forms an element portion on the first surface side. Then, the method processes the substrate so that the positions of the end faces of the through wirings measured from the substrate surface on the first surface side are made smaller in depth than the positions of the end faces of the through wirings measured from the substrate surface on the second surface side.