PCB Insulating Sleeves for Through-Hole Creepage and Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing production methods for circuit boards result in large electrically unused regions due to the need for creepage distances around through-holes, which reduces the current-carrying capacity and increases parasitic inductance and resistance, especially when reinforced with copper vias and annular copper layers.
Innovation Solution
Integrating insulating sleeves made of high-strength, high-insulation materials into the circuit board through-holes, eliminating the need for copper vias and allowing metal layers to be closer to the through-holes while maintaining required creepage distances, thereby increasing the usable board surface area and copper cross-section.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If copper vias and annular copper layers are used to reinforce through-holes, then mechanical strength is improved, but creepage distances are increased and electrical performance deteriorates
Solution Approach 1:
An insulating sleeve is introduced as an intermediary component between the through-hole and the copper layers. The sleeve provides mechanical reinforcement while its insulating properties allow copper layers to be positioned closer to the through-hole, reducing creepage distances and improving electrical performance without sacrificing mechanical strength.
Solution Approach 2:
The reinforcement function is segmented into two separate components: the insulating sleeve provides mechanical strength, while the copper layers provide electrical functionality. This separation allows each component to be optimized independently, with the sleeve enabling closer positioning of copper layers without direct contact, thus reducing creepage distances.
2Reliability
If creepage distances are maintained around through-holes, then electrical insulation is improved, but usable board area is reduced
Solution Approach 1:
The insulating sleeve acts as a mediator that provides the necessary electrical insulation function, allowing copper layers to extend closer to the through-hole. This reduces the lateral creepage distance required while maintaining adequate electrical insulation through the vertical insulation provided by the sleeve.
Solution Approach 2:
The insulation function is shifted from the lateral dimension (creepage distance in the board plane) to the vertical dimension (insulation through the sleeve wall). This dimensional transition allows copper layers to be positioned closer in the lateral direction while maintaining insulation through the vertical path along the sleeve.
3Strength
If through-holes are reinforced with additional copper layers, then mechanical strength is improved, but parasitic inductance and resistance increase
Solution Approach 1:
The insulating sleeve enables a more direct connection between copper layers and the through-hole region without requiring additional annular copper layers. This reduces the number of copper transitions and connections, thereby minimizing parasitic inductance and resistance while the sleeve itself provides the necessary mechanical reinforcement.
Data Source
AI summary
A circuit board includes a plurality of circuit board layers arranged one on top of the other, wherein through-holes are integrated in the circuit board, wherein the through-holes are configured to receive metal screws that screw the circuit board to a heat sink. Insulating sleeves made of an insulating material are integrated into the circuit board, wherein the through-holes are formed in the circuit board in the region of the insulating sleeves.