Implantable Feedthrough Hard Solder Reservoir Design
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Solution Overview
Problem
Feedthroughs for implantable medical electronic devices are susceptible to deformation and damage, especially when using surface mount technology, requiring elaborate precautions and costly testing to ensure reliable electrical contact, which complicates the assembly process.
Innovation Solution
The feedthrough design features a primary connection element with a widening passage that serves as a material reservoir, filled with hard solder and optionally soft solder or sintered materials, eliminating the need for protective measures and allowing for precise material feeding during assembly, facilitating reflow soldering and reducing susceptibility to deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If connection pins are used in feedthroughs with surface mount technology, then electrical contact can be established, but the connection pins are susceptible to deformation and damage requiring elaborate precautions and costly testing
Solution Approach 1:
The connection pin is divided into functionally distinct segments: a biocompatible outer shell for hermetic sealing and a separate inner core for electrical conduction and soldering. This segmentation allows each part to be optimized independently, reducing the complexity of handling the entire connection pin as a single vulnerable component.
Solution Approach 2:
The passage in the insulator is pre-formed with a widening section that serves as a material reservoir, and the connection pin is pre-positioned within this widened section before final assembly. This preliminary positioning and material preparation eliminate the need for elaborate precautions during assembly, as the design inherently guides the soldering process.
2Adaptability or versatility
If connection pins are made biocompatible for external contact, then biocompatibility is achieved, but connection to electronics inside the housing becomes more difficult
Solution Approach 1:
The connection pin exhibits local quality differentiation: the outer shell is made of biocompatible material for external body contact, while the inner core uses solderable materials for electrical connection to electronics. This localized material selection allows the single component to satisfy both biocompatibility requirements and manufacturing ease requirements in different regions.
Solution Approach 2:
The connection pin is constructed as a composite structure with a biocompatible outer shell (e.g., titanium, tantalum, or gold) and an inner core of solderable material (e.g., copper or aluminum). This composite construction enables the pin to provide both biocompatibility for external contact and ease of connection to internal electronics through the solderable core.
3Reliability
If elaborate precautions and testing are implemented for feedthrough assembly, then reliability is improved, but manufacturing costs and process complexity increase
Solution Approach 1:
The passage is pre-formed with a widening section that serves as a material reservoir, and the connection pin is pre-positioned within this widened section. The hard solder is pre-placed in the widened section, creating a self-guiding assembly structure that inherently ensures proper alignment and material flow during reflow soldering, eliminating the need for costly post-assembly testing.
Solution Approach 2:
The widened passage section acts as a self-regulating material reservoir that automatically controls solder flow during the reflow process. The geometry of the widening section and the positioning of the connection pin create a self-aligning system that ensures reliable electrical contact without requiring external monitoring or adjustment, thereby reducing manufacturing costs.
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 design eliminates the risk of deformation and damage to connection pins, simplifies the assembly process, and reduces costs by eliminating the need for elaborate precautions and testing, enabling reliable and efficient electrical contact in a surface-mount device environment.
Implementation Method 1
enabling reliable and efficient electrical contact in a surface-mount device environment
Implementation Method 2
filled with hard solder and optionally soft solder or sintered materials, eliminating the need for protective measures and allowing for precise material feeding during assembly, facilitating reflow soldering
Data Source
AI summary
A feedthrough for an implantable medical electronic device that has a housing and a header. The feedthrough having an insulator that has a housing-side surface and a header-side surface opposite it, a feedthrough flange surrounding the insulator, and at least one primary connection element penetrating the insulator and for connection of an electrical or electronic component of the device. This electrical or electronic component is arranged in the housing. The connection element is fastened by a hard solder connection, so that it is fluid-tight in a passage of the insulator. The primary connection element has a housing-side end that is essentially even with the housing-side surface of the insulator or is recessed into the insulator with respect to this surface.