Implantable Medical Device Header Two-Shot Molding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for forming headers for implantable medical devices (IMDs) face challenges in efficiently integrating components like antennas and electrodes while ensuring proper mechanical and electrical coupling, often resulting in defects and increased handling risks for delicate components.
Innovation Solution
A two-shot molding process is employed, where a first-shot assembly with protrusions is created to interact with the second-shot mold, preventing electrode coverage and guiding molding material flow, and an attachment plate is embedded to mechanically couple the header to the IMD body, reducing handling and potential defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional molding processes are used to form headers for implantable medical devices, then the manufacturing process is simpler, but component integration is inefficient and handling of delicate parts increases defect risks
Solution Approach 1:
The molding process is divided into two sequential shots: first forming the header body with basic components, then forming the attachment plate with embedded features. This segmentation allows each shot to be optimized independently, reducing defects while managing complexity through structured process division.
Solution Approach 2:
The first-shot assembly is formed in advance with specific features (protrusions, recesses, alignment elements) that prepare it for the second molding shot. This preliminary action ensures proper component positioning and integration before final attachment plate formation, preventing defects during subsequent handling and assembly.
2Reliability
If components are handled separately before assembly, then each component can be individually prepared, but handling risks and potential defects increase
Solution Approach 1:
Multiple components (attachment plate, antenna, electrode, insulation material) are combined into a single integrated header structure through the two-shot molding process. This merging eliminates separate handling steps, reduces assembly complexity, and improves reliability by ensuring precise integration of all components in one manufactured unit.
Solution Approach 2:
The first-shot assembly serves as an intermediary structure that facilitates the integration of subsequent components during the second molding shot. It provides predefined interfaces (protrusions, recesses, alignment features) that guide the attachment plate and other components into proper positions, simplifying the overall manufacturing process while ensuring reliable component integration.
3Reliability
If the electrode is exposed during molding, then it can be accessed for electrical coupling, but molding material may cover and contaminate the electrode
Solution Approach 1:
The header structure incorporates localized features (protrusions, recesses, shielding walls) that specifically protect the electrode area from molding material contamination while leaving other areas accessible. This local quality approach ensures the electrode remains clean for electrical coupling without compromising the overall manufacturing process.
Solution Approach 2:
The first-shot assembly is formed in advance with protective features (protrusions, recesses, alignment elements) that prevent molding material from contacting the electrode during the second shot. This preliminary anti-action eliminates the need for post-molding electrode cleaning or protection steps, maintaining electrode cleanliness while preserving accessibility for electrical coupling.
4Strength
If the attachment plate is not embedded in molding material, then it can be easily removed for assembly, but mechanical coupling strength decreases
Solution Approach 1:
The attachment plate is nested within the header body through the two-shot molding process, with the second shot forming the attachment plate embedded in the first-shot assembly. This nesting creates a strong mechanical bond while maintaining ease of manufacture through the integrated molding process, eliminating the need for separate attachment mechanisms.
Solution Approach 2:
The first-shot assembly is formed in advance with predefined embedding features (protrusions, recesses, alignment elements) that guide the attachment plate into proper position during the second shot. This preliminary action ensures strong mechanical coupling while simplifying the manufacturing process by eliminating complex assembly steps.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Techniques for forming a header for an implantable medical device via a two-shot molding process are described. The two-shot molding processes may include a first molding step that creates a first-shot assembly and a second molding step that creates a second-shot assembly. The first-shot assembly may be formed to include one or more protrusions configured to interact with a second-shot mold and/or molding material in the second molding step. The second molding step may be configured to overmold the first-shot assembly. The header may include an attachment plate at least partially embedded in molding material and configured to be mechanically coupled to a body of the implantable medical device.