Functional Laminate Patchwork Layer Stress Absorption
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Solution Overview
Problem
The existing methods for manufacturing functional laminates, such as smart cards, often result in mechanical stress and cracking due to differential shrinking properties between plastic cover layers and embedded chip modules during the lamination process, leading to reduced service life.
Innovation Solution
Incorporating a patchwork layer made of thermoplastic polyurethane (TPU) or pure polyurethane (PU) with alternating zones of polycarbonate, which acts as an auxiliary material to absorb mechanical stress and prevent cracking by providing smoother, uninterrupted bridges between layers, thereby reducing stress on the chip module.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If layers are laminated using heat and pressure, then the layers are joined together to form a functional laminate, but the plastic material shrinks causing mechanical stress that leads to cracking or delaminating
Solution Approach 1:
The patent introduces a layer with modified shrinkage parameters (different thermal expansion coefficient) between the chip module and cover layers. This layer undergoes controlled shrinkage during lamination that compensates for the shrinkage of adjacent layers, reducing mechanical stress and preventing cracking while maintaining joint strength.
Solution Approach 2:
The patent uses a composite structure where a layer with specific material properties (different thermal expansion characteristics) is combined with the chip module and cover layers. This composite approach allows the intermediate layer to absorb differential shrinkage stresses, preventing failure of the overall laminate structure.
2Reliability
If a rubberlike auxiliary layer is added between layers to reduce stress, then cracking is prevented, but the device complexity increases
Solution Approach 1:
The patent applies the auxiliary layer with different thermal expansion properties only in specific locations where stress concentration occurs (between the chip module and cover layers), rather than throughout the entire laminate. This localized approach prevents cracking at critical interfaces while minimizing the increase in overall device complexity.
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
The use of TPU or PU patchwork layers effectively absorbs mechanical stress and prevents cracking, enhancing the structural integrity and longevity of the laminated product by maintaining the chip module's integrity and preventing delamination.
Implementation Method 1
Incorporating a patchwork layer made of thermoplastic polyurethane (TPU) or pure polyurethane (PU) with alternating zones of polycarbonate, which acts as an auxiliary material to absorb mechanical stress and prevent cracking
Implementation Method 2
During cooling, the support and the chip exhibit different shrinking properties, resulting in stresses which may lead to cracks
Data Source
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AI summary
The invention refers to a functional laminate (1) comprising at least two colaminated layers (2, 2', 3, 3'), wherein at least one of the layers (2, 2', 3, 3') is a patchwork layer consisting of zones (2.1 to 2.n, 2'.1 to 2'.n, 3.1 to 3.n, 3'.1 to 3'.n) of multiple types distinct from each other, wherein at least one zone (2.1 to 2.n, 2'.1 to 2'.n, 3.1 to 3.n, 3'.1 to 3'.n) of a first type comprises a first material and one zone (2.1 to 2.n, 2'.1 to 2'.n, 3.1 to 3.n, 3'.1 to 3'.n) of a second type comprise a second material, distinct from the first material, and wherein the proximate layer or layers (2, 2', 3, 3') adjacent to the patchwork layer (2, 2', 3, 3') comprises or comprise at least one zone (2.1 to 2.n, 2'.1 to 2'.n, 3.1 to 3.n, 3'.1 to 3'.n) comprising the first or the second material. Furthermore the invention refers to a Method for manufacturing such a functional laminate (1), the method comprising the following steps: - providing at least one patchwork layer (2, 2', 3, 3'); - stacking the patchwork layer (2, 2', 3, 3') with at least one other layer (2, 2', 3, 3') in order to obtain a stack of layers (2, 2', 3, 3'), wherein at least one proximate layer (2, 2', 3, 3') directly adjacent to the patchwork layer comprises at least one zone (2.1 to 2.n, 2'.1 to 2'.n, 3.1 to 3.n, 3'.1 to 3'.n) comprising a first material or a second material; - laminating the stack of layers (2, 2', 3, 3') together by heat and/or pressure and/or gluing.