Electronic Pen Circuit Layout for Waterproofing Under Water Pressure
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Solution Overview
Problem
Existing electronic pens face challenges in maintaining a highly waterproof function and resistance to water pressure, particularly when exposed to environments like rain or water bodies, due to deformation and stress on circuit components, which can affect their operation.
Innovation Solution
The electronic pen employs a two-layer circuit board structure with heat-resistant components on one surface and sensitive components on the other, sealed by a thermosetting resin, and uses projected portions and a sealing member to fill gaps, along with protrusions to stabilize the circuit board and prevent warping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the circuit board is sealed using conventional waterproofing methods, then waterproof function is improved, but the circuit board deforms and circuit components are stressed under water pressure
Solution Approach 1:
The patent applies different properties to different parts of the circuit board by installing heat-resistant circuit components on the lower surface (facing the board holder) and non-heat-resistant components on the upper surface. The board holder itself is designed with heat-resistant properties to protect the heat-resistant components from the thermosetting resin curing process while allowing standard components to remain on the other side.
Solution Approach 2:
The patent performs preliminary waterproofing by sealing the circuit board with thermosetting resin before the pen is exposed to water. This pre-sealing prevents water from penetrating to the circuit board during normal use, eliminating the need for additional waterproof measures that would add complexity or compromise component stability.
2Strength
If heat-resistant circuit components are installed on the lower surface, then resistance to water pressure is improved, but manufacturing complexity increases
Solution Approach 1:
The patent segments the circuit board into two functional surfaces: the lower surface (first surface) that contacts the board holder and requires heat-resistant components for water pressure resistance, and the upper surface (second surface) that can accommodate standard non-heat-resistant components. This segmentation allows each surface to be optimized for its specific functional requirements.
Solution Approach 2:
The patent changes the thermal resistance parameter of specific circuit components based on their location. Heat-resistant components are selected for the lower surface that will be in contact with the thermosetting resin and subjected to water pressure, while standard components are used on the upper surface where such extreme conditions do not apply.
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 configuration ensures robust waterproofing and resistance to water pressure, preventing deformation and ensuring reliable operation of the pen even when submerged.
Implementation Method 1
a thermosetting resin formed over the second surface of the circuit board seals the opening
Data Source
AI summary
An electronic pen that transmits a position indication signal. The electronic pen includes a board housing including a recessed portion inside of the board housing, a circuit board housed in the recessed portion of the board housing, a plurality of circuit components including first components arranged on a first surface of the circuit board, and a thermosetting resin formed over a second surface of the circuit board that is opposite the first surface of the circuit board.The thermosetting resin seals an opening over a lower surface of the recessed portion of the board housing. The first components arranged on the first surface of the circuit board are more affected by heat than second circuit components provided on the second surface of the circuit board.