Ceramics Green Sheet Lamination for Gas Sensor Yield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing gas sensors, such as those for measuring NOx concentration, face challenges in achieving high lamination accuracy due to deformation of ceramics green sheets during the printing and drying process, leading to yield deterioration and laminating failures.
Innovation Solution
A method involving the formation of a preceding lamination sheet by bonding at least two blank ceramics green sheets, followed by screen printing a pattern on a non-preceding lamination sheet, which is then laminated in a predetermined order with the preceding sheet, using a bonding paste with a specific binder and solvent composition to minimize deformation and ensure stable adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If printing is performed multiple times on a green sheet to form patterns, then the circuit pattern can be formed on each layer, but the green sheet deforms and lamination accuracy deteriorates
Solution Approach 1:
The manufacturing process is segmented into two distinct sequences: (1) laminate multiple green sheets first to form a thick laminated body, then print patterns on the laminated structure; or (2) print patterns on individual green sheets, then laminate them. This segmentation avoids repeated printing-deformation cycles on the same sheet while achieving the required circuit patterns on each layer.
Solution Approach 2:
The green sheets are prepared with patterns printed in advance before lamination, or the lamination structure is prepared in advance before pattern printing. This preliminary action ensures that printing operations are minimized and performed on stable, non-deformed green sheets or laminated bodies, preventing deformation-related accuracy loss.
2Strength
If multiple green sheets are laminated with bonding paste, then the laminated body can be formed, but the repeated printing and drying processes cause deformation
Solution Approach 1:
The lamination and printing operations are segmented into separate process stages. Green sheets are either laminated first without patterns, then patterns are printed on the laminated body; or patterns are printed on individual sheets, then they are laminated. This eliminates the problematic sequence of printing then re-laminating the same sheet multiple times.
Solution Approach 2:
The bonding paste serves as an intermediary that enables lamination without requiring repeated printing on the same green sheet. By applying bonding paste to the lamination interface rather than printing circuit patterns on each sheet multiple times, strong adhesion is achieved while minimizing deformation.
3Strength
If thick green sheets are used to ensure structural integrity, then the sensor element has sufficient strength, but deformation during printing becomes more significant
Solution Approach 1:
Patterns are printed on green sheets before lamination, or the laminated body structure is prepared before final pattern printing. This preliminary action ensures that thick green sheets undergo printing only once under controlled conditions, minimizing deformation while maintaining structural integrity.
Solution Approach 2:
The printing process parameters (such as paste viscosity, drying conditions, and printing pressure) are optimized for thick green sheets to minimize deformation. Additionally, the lamination pressure and temperature parameters are adjusted to accommodate the thickness while achieving proper bonding without excessive deformation.
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 allows for the formation of a laminated body with high accuracy, reducing deformation and lamination defects, thereby improving the yield and reliability of gas sensors by stabilizing the adhesion between green sheets.
Implementation Method 1
bonding paste with a specific binder and solvent composition to minimize deformation and ensure stable adhesion
Implementation Method 2
each of the ceramics green sheets includes an oxygen ion conductive solid electrolyte as a ceramics component
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of forming a laminated body includes a first lamination step of forming a preceding lamination sheet which is substantially treated as one green sheet by laminating and bonding at least two green sheets out of a plurality of green sheets with predetermined pattern printed thereon; a printing step of printing a predetermined pattern on the preceding lamination sheet and at least one non-preceding lamination sheet which is a not used for forming the preceding lamination sheet; and a second lamination step of laminating and bonding the preceding lamination sheet and non-preceding lamination sheet, on which the predetermined pattern is printed in the printing step, in a predetermined order.