Metallization Segmentation for Reliable Piezoelectric Contacts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical components, particularly piezoelectric actuators, face challenges in achieving reliable and durable external contacts due to material diffusion and mixed wettability issues during the metallization process, which affects the strength and reliability of the electrical connections.
Innovation Solution
A two-stage firing process is employed to form first and second metallizations with different wettability properties, where the first metallization has a glass content for strong adhesion to the base body and low wettability with solder, while the second metallization has no glass content for improved solderability, allowing for selective attachment of contact elements without material diffusion, and a U-shaped design for flexible bridging of cracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single metallization layer is applied to the base body, then the manufacturing process is simple, but the solderability and adhesion cannot be simultaneously optimized
Solution Approach 1:
The metallization is divided into two separate layers: a first metallization layer (e.g., copper) applied directly to the base body for strong adhesion, and a second metallization layer (e.g., tin or tin alloy) applied over the first layer for improved solderability. This segmentation allows each layer to be optimized for its specific function, resolving the contradiction between manufacturing simplicity and connection reliability.
Solution Approach 2:
The patent employs a composite metallization structure where two different metallization materials are combined in layers. The first metallization provides mechanical bonding to the ceramic base body, while the second metallization provides solderability. This composite approach enables simultaneous optimization of both adhesion and solderability properties that cannot be achieved with a single material.
2Strength
If glass content is increased in metallization for strong adhesion to base body, then adhesion strength improves, but solderability deteriorates
Solution Approach 1:
The metallization function is segmented into two layers: the first metallization layer contains glass content optimized for strong adhesion to the ceramic base body, while the second metallization layer has reduced or no glass content to ensure good solderability. This functional segmentation resolves the contradiction between adhesion strength and solderability.
Solution Approach 2:
Different glass content levels are applied locally to different layers of the metallization structure. The first layer near the base body has higher glass content for maximum adhesion, while the second layer exposed to solder has lower glass content for optimal solderability. This local quality variation allows each region to have the properties needed for its specific function.
3Productivity
If metallization layers are applied in a single firing process, then the process is efficient, but material diffusion between layers occurs
Solution Approach 1:
The metallization process uses periodic (sequential) firing actions instead of a single continuous firing. The first metallization layer is applied and fired separately, then the second metallization layer is applied and fired separately. This periodic processing prevents material diffusion between layers while maintaining production efficiency through optimized firing cycles.
Solution Approach 2:
The first metallization layer is completely applied and fired before applying the second metallization layer. This preliminary action ensures that the first layer is stable and non-reactive before the second layer is introduced, preventing unwanted material diffusion while maintaining an efficient two-stage process.
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 ensures strong and reliable electrical connections by preventing material diffusion, allowing for flexible contact elements that can bridge cracks without impairing the component's flexibility, and maintaining the base body's integrity during mechanical stress.
Implementation Method 1
The first metallization has a glass content and the second metallization has no glass content or a lower glass content than the first metallization. Due to the proportion of glass in the first metallization, a particularly strong connection of the first metallization to the base body, in particular to ceramic layers of the base body, can be achieved.
Implementation Method 2
With such a two-stage firing process of the metallizations, mixing of the materials of the metallizations can be prevented particularly well. In particular, a diffusion of material components from one of the metallizations into the other metallization can be prevented.
Implementation Method 3
The first and the second metallization have different wettability with solder material. Due to the different wettability, it can be achieved that a contact element, which is to be attached to at least one of the metallizations, is attached sufficiently strongly to one of the two metallizations
Data Source
Figure 1~2
Figure 3
Figure 4A~4D
AI summary
The invention specifies an electrical component (1) comprising at least one outer contact (7) having a first metallization (8) and a second metallization (9), wherein the metallizations (8, 9) are baked in, and wherein the second metallization (9) only partially covers the first metallization (8). The invention further specifies an electrical component (1) having at least one frame-like metallization (8, 9). The invention further specifies an electrical component (1) comprising a first and a second metallization (8, 9) which have a different degree of wettability with solder material. The invention furthermore specifies a method for establishing contact with an electrical component (1).