Inlay Polymerization for Sealed Electrical Feedthroughs
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Solution Overview
Problem
The challenge of achieving a permanent, sealed connection between metal inserts and polymer surrounding materials in electrical feedthroughs through plastic housings is hindered by thermal expansion differences, leading to gaps that can compromise sealing and allow moisture ingress, causing short circuits in electronic components.
Innovation Solution
A method involving the polymerization of a monomer in contact with the metal insert, where the insert's temperature is increased to ensure heat flow from the insert to the monomer, optimizing polymerization and adhesion, and potentially using resistive or inductive heating to quickly raise and lower the insert's temperature for efficient polymerization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the metal insert is overmoulded with hot plastic, then the plastic can be attached to the metal, but thermal expansion differences cause the plastic to detach and form gaps that compromise sealing
Solution Approach 1:
The patent changes the temperature parameter during polymerization by heating the metal insert to above the monomer's polymerization temperature. This ensures complete polymerization at the contact surface, creating a durable bond that withstands thermal expansion differences and maintains sealing reliability.
Solution Approach 2:
The patent applies preliminary heating to the metal insert before monomer contact. This pre-heating ensures that when the monomer is applied, the temperature gradient immediately drives heat from the metal to the monomer, initiating and sustaining complete polymerization at the interface before thermal expansion issues can arise.
2Quantity of substance
If the monomer is brought into contact with the metal insert, then polymerization can occur, but the metal's thermal conductivity withdraws energy from the polymerization process
Solution Approach 1:
Instead of trying to prevent heat loss to the metal (the conventional approach), the patent inverts the approach by deliberately heating the metal to a temperature above the monomer's polymerization temperature. This reverses the heat flow direction, making the metal a heat source rather than a heat sink, thereby ensuring complete polymerization.
3Strength
If the monomer polymerizes at the contact surface with the insert, then adhesion is formed, but redox reactions or free protons can deactivate the polymerization process
Solution Approach 1:
The patent changes the temperature parameter to above the monomer's polymerization temperature, which provides sufficient thermal energy to overcome deactivation by redox reactions or free protons. The elevated temperature ensures that polymerization proceeds to completion despite these interfering chemical reactions at the metal surface.
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 complete polymerization and strong adhesion of the polymer to the insert, preventing gaps and maintaining a tight seal even under thermal stress, effectively protecting sensitive electronic components from moisture and electrical interference.
Implementation Method 1
The temperature TE of the insert is at least briefly increased to at least the temperature TM that the monomer assumes at most during its exothermic polymerization
Implementation Method 2
the monomer assumes at most during its exothermic polymerization to form the polymer
Implementation Method 3
the heat flow always runs from the insert to the monomer
Implementation Method 4
potentially using resistive or inductive heating to quickly raise and lower the insert's temperature
Implementation Method 5
potentially using resistive or inductive heating to quickly raise and lower the insert's temperature
Data Source
Figure 1a
Figure 1b~1c
Figure 2a~2b
AI summary
The invention relates to a method (100) for establishing a connection between an inlay (1, 1', 1") and a polymer (3) at least partially surrounding the inlay, wherein a monomer (2) is brought into contact (110) with the inlay (1, 1', 1") and is subsequently polymerized (120) to form the polymer (3), wherein the temperature TE of the inlay (1, 1', 1") is increased (130) at least briefly at least to that temperature TM that the monomer (2) assumes at its maximum during its exothermic polymerization (120) to form the polymer (3), and/or that ensures that the heat flow always runs from the inlay (1, 1', 1") to the monomer (2). The invention also relates to a method (200), (300), (400) for the sealing integration of an inlay (1, 1', 1") in a component (5). The invention also relates to a device (50) for carrying out the method (100), comprising a conveyor (51) for a lead frame (11) in which a multiplicity of inlays (1, 1', 1") are able to be fed, and an at least two-part (52a, 52b) mould (52) which is closable about an individual inlay (1, 1', 1") and has a feed (53) for feeding the monomer (2) into the space (54) between the mould (52) and the inlay (1, 1', 1"), wherein a current supply (55) is provided for the resistive and/or inductive heating (131) of the inlay (1, 1', 1") surrounded by the mould (52).