Implantable Device Case Fit-Up Using Selective Encapsulation
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Solution Overview
Problem
Existing implantable medical devices face challenges in ensuring proper fit-up and sealing due to component variations and aging, which can lead to manufacturing difficulties and potential device failures such as hermeticity breaches and electrical failures.
Innovation Solution
The use of first and second encapsulant layers molded on or adjacent to components, which accommodate size changes and tolerances by defining air gaps, allowing for flexible assembly and welding without accounting for component size variations, thereby simplifying the design process and ensuring secure fit-up within the device housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional frames and spacers are used to accommodate component variations, then component fit-up is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent removes traditional frames and spacers from the device assembly by using the encapsulant material to directly secure components to the canister wall. The encapsulant performs multiple functions previously requiring separate structural elements, thereby reducing device complexity while maintaining manufacturing precision.
Solution Approach 2:
The encapsulant material serves multiple functions: it secures components to the canister wall, absorbs thermal expansion, provides electrical isolation, and ensures hermetic sealing. This multi-functionality replaces what previously required multiple separate components (frames, spacers, thermal barriers), reducing overall device complexity.
2Reliability
If frames and spacers with air gaps are provided to account for component swelling and shifting, then reliability is improved, but manufacturing precision requirements worsen
Solution Approach 1:
The patent changes the physical state and properties of the encapsulant material to create a compliant interface that can absorb thermal expansion and accommodate component variations. The encapsulant's viscoelastic properties allow it to deform and adapt to component swelling and shifting, maintaining reliable electrical connections without requiring tight manufacturing tolerances for air gaps.
Solution Approach 2:
The encapsulant material is applied beforehand to create a cushioning layer between components and the canister wall. This layer anticipates and absorbs future thermal expansion, component swelling, and manufacturing variations, preventing stress on electrical connections and maintaining reliability without requiring precise pre-calculated air gaps.
3Reliability
If tight tolerances are applied to account for component variations, then hermetic sealing is improved, but ease of manufacture worsens
Solution Approach 1:
The encapsulant material acts as a flexible interface layer between the rigid canister wall and internal components. This flexible layer accommodates component variations and thermal expansion while maintaining the hermetic seal, eliminating the need for tight tolerances in canister fit-up and simplifying the welding process.
Solution Approach 2:
The encapsulant serves as an intermediary layer between the canister wall and internal components, absorbing dimensional variations and preventing stress transmission to the hermetic seal. This mediator allows the canister welds to be performed without requiring precise alignment and tolerance control, significantly easing manufacturing.
Data Source
AI summary
Methods of manufacturing a medical device, and medical devise made by such methods. One or more layers or portions of encapsulant are used to secure components of a medical device in a housing. The case fit-up of the device may be modified to reduce reliance on size tolerances of components of the medical device, while still accounting for any anticipated changes in component size due to aging.