Battery Module FPCB Insulation Using Stacked Polyimide Layers
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Solution Overview
Problem
Lithium secondary batteries face safety issues due to decomposition reactions under abnormal conditions, leading to heat, gas generation, and potential ignition or explosion, and conventional management systems only detect risks without providing a fundamental solution.
Innovation Solution
A battery module incorporating a flexible printed circuit board (FPCB) with a multilayer insulating structure using stacked polyimide layers and adhesive layers, which enhances insulation properties and reduces the risk of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer insulating structure is used in the FPCB, then the device complexity is reduced, but the insulation reliability deteriorates due to potential defects
Solution Approach 1:
The insulating layer is divided into multiple polyimide layers (first, second, and third polyimide layers) stacked in sequence. This segmentation allows each layer to provide independent insulation protection, so that defects in one layer do not compromise the overall insulation reliability. The multi-layer structure effectively distributes the insulation function across multiple independent barriers.
Solution Approach 2:
The patent uses a composite structure combining multiple polyimide layers with different thicknesses (5μm-20μm each) to create a robust insulating system. The composite nature of the multi-layer polyimide structure provides enhanced insulation reliability compared to a single-layer design, while maintaining compatibility with the existing FPCB architecture.
2Reliability
If the insulating layer thickness is increased to improve insulation, then the insulation reliability improves, but the manufacturing precision requirements increase
Solution Approach 1:
Instead of creating one thick insulating layer that would require precise thickness control, the patent segments the total insulation thickness into multiple thinner polyimide layers (5μm-20μm each). This segmentation reduces the manufacturing precision requirements for each individual layer while achieving the same or better total insulation effect, as thinner layers are easier to manufacture with consistent thickness.
Solution Approach 2:
The patent applies different thicknesses to different polyimide layers based on local insulation requirements. The first polyimide layer has a thickness of 5μm-20μm, the second has 5μm-15μm, and the third has 5μm-10μm, creating a gradient structure that optimizes insulation where needed while reducing manufacturing complexity elsewhere.
3Reliability
If multiple polyimide layers are stacked to improve insulation, then the insulation reliability improves, but the device complexity increases
Solution Approach 1:
The patent merges multiple polyimide layers into a unified insulating structure that functions as an integrated insulation system. By combining the first, second, and third polyimide layers with thicknesses of 5μm-20μm, 5μm-15μm, and 5μm-10μm respectively, the design achieves enhanced insulation reliability while presenting a cohesive structural solution that does not significantly increase overall device complexity.
Data Source
AI summary
The present disclosure relates to a battery module having significantly improved insulation properties. According to an aspect of the present disclosure, there is provided a battery module including: a cell stack including a plurality of battery cells; a flexible printed circuit board positioned on at least one surface of the cell stack; and a housing having an internal accommodation space in which the cell stack and the flexible printed circuit board are accommodated, wherein the flexible printed circuit board includes a base substrate, a metal layer positioned on the base substrate, and an insulating layer positioned on the metal layer, and the insulating layer includes a plurality of stacked polyimide layers, and a first adhesive layer positioned between the adjacent polyimide layers.