Flexible Substrate Electronic Component Connection via Thermoset Fill
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for connecting electronic components to conductive tracks on flexible substrates face issues with interference from electromagnetic radiation, resistance variations, and unstable interconnections, leading to poor signal quality and durability.
Innovation Solution
A method involving a connection layer with cutouts on the conductive track filled with a thermosetting material, which is heated to form a durable mechanical and electrical connection, using a thermoplastic material for the connection layer and potentially a different thermoplastic material for the flexible substrate, with a cover layer to reduce stress and improve adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermoplastic resin substrate with conductive pattern lands is used to form electrical interconnected portions by overlapping and softening, then electrical connection is achieved, but the interconnections have poor stability and are prone to resistance variations, cracking, or loss of connection upon repeated flexing and stretching
Solution Approach 1:
The patent uses a composite structure combining a flexible substrate with a separate connection layer made of thermoplastic material. This layered composite approach allows the substrate and connection layer to have different mechanical properties, with the connection layer providing stable electrical interconnections that are less prone to degradation during flexing and stretching, thereby resolving the contradiction between reliability and strength.
Solution Approach 2:
The patent divides the connection structure into separate functional layers: the flexible substrate containing conductive tracks and a distinct connection layer with openings for electrical interconnected portions. This segmentation allows each layer to be optimized independently - the substrate for flexibility and the connection layer for stable electrical connection, solving the contradiction between durability and connection stability.
2Strength
If the connection layer is heated above the softening temperature of the thermoplastic material, then adhesion and mechanical connection are improved, but the flexible substrate may deform or lose structural integrity
Solution Approach 1:
The patent carefully controls the heating parameters (temperature and time) during the connection process. By optimizing these parameters, the connection layer achieves sufficient softening and adhesion to the substrate without exceeding the thermal tolerance of the flexible substrate, thus maintaining structural integrity while improving connection strength.
Solution Approach 2:
The connection layer is pre-formed with openings and conductive elements positioned before the final heating and bonding step. This preliminary preparation ensures that when heating occurs, the material flows and bonds precisely where needed without requiring excessive heat or time that could damage the substrate structure.
3Ease of manufacture
If a single-layer connection structure is used, then manufacturing is simpler, but electrical insulation and mechanical stability cannot be simultaneously achieved
Solution Approach 1:
The connection layer is constructed as a composite with multiple functional components: thermoplastic material for mechanical bonding, conductive elements for electrical connection, and insulating properties. This composite structure within a single layer achieves electrical insulation and mechanical stability simultaneously while remaining manufacturable through processes like co-extrusion or lamination.
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 enhances the durability and stability of the electrical connection by forming a mechanically decoupled electrical connection, improving adhesion and reducing the likelihood of delamination and damage, especially during flexing and stretching of the substrate.
Implementation Method 1
raising a temperature of the connection layer close to or above a softening temperature (Tg) of the thermoplastic material of the connection layer. Heating the connection layer to above a softening temperature may result in a softening and thermoplastic deformation of the connection layer
Implementation Method 2
Heating the thermosetting material to above its thermosetting temperature may activate a solidification of the thermosetting material
Data Source
AI summary
An electronic component (1) is connected to a conductive track (2) on a flexible substrate (3). A connection layer (4) of a composition comprising a thermoplastic material (TPM1) is provided on the conductive track (2). The connection layer (4) has at least one cutout (5) aligned to overlap the conductive track (2). A thermosetting material (TSM1) in liquid state is used to fill the cutout (5). The electronic component (1) is provided on top of the connection layer (4). By applying heat, a temperature of the connection layer (4) is raised to above a softening temperature of the thermoplastic material (TPM1). Pressure is applied to form a mechanical connection. By the application of heat (H) a temperature of the thermosetting material (TSM1) is raised above its thermosetting temperature for solidifying the thermosetting material (TSM1) and forming an electrical connection (E).