Thermal Print Head Convex Portion Rounded Ends
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Solution Overview
Problem
The existing thermal print heads with silicon-containing substrates have a convex portion that protrudes sharply in the main scanning direction, leading to potential damage of the recording medium during printing.
Innovation Solution
A thermal print head design featuring a substrate with a convex portion that includes a top surface and inclined surfaces, where at least one end forms a third and fourth inclined surface connected to the main surface, preventing the convex portion from sharpening and reducing the risk of medium damage, achieved through anisotropic etching and specific mask layer configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the convex portion is formed with steeply inclined end surfaces for compact design, then the device size is reduced, but the end becomes sharp causing damage to the recording medium
Solution Approach 1:
The patent applies curvature by forming rounded end surfaces on the convex portion instead of sharp edges. The end surfaces are designed with a radius of curvature R1 (0.1-10 μm) and R2 (0.1-10 μm), creating a smooth过渡 that eliminates sharp corners while maintaining compact dimensions. This curvilinear design prevents concentration of stress at the ends, thereby avoiding damage to the recording medium during printing operations.
2Manufacturing precision
If the convex portion has a sharp end for precise heat generation, then printing precision is improved, but the risk of medium damage increases
Solution Approach 1:
The patent implements local quality by creating different surface characteristics in different regions of the convex portion. The top surface maintains a flat or slightly curved configuration for precise heat generation and contact with the recording medium, while the end surfaces are specifically designed with larger radi of curvature to be non-sharp. This localized differentiation allows the convex portion to simultaneously achieve printing precision at the top and safety at the ends.
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 design inhibits the sharpening of the convex portion's ends, minimizing contact area with the recording medium and enhancing printing quality while maintaining high heat conductivity and cost-effectiveness.
Implementation Method 1
forming a main surface and a convex portion on the substrate by an anisotropic etching
Data Source
AI summary
The present disclosure provides a thermal print head and a method of fabricating the thermal print head. The thermal print head includes a substrate made of a semiconductor material and having a main surface and a convex portion, a resistor layer including a plurality of heat generating portions on the convex portion, and a wiring layer conducted to the plurality of heat generating portions and formed to contact the resistor layer. The convex portion has a top surface, a first inclined surface and a second inclined surface. At least one of two ends of the convex portion in the main scanning direction forms a third inclined surface connected to the main surface and the first inclined surface, and a fourth inclined surface connected to the main surface and the second inclined surface.