Head Chip Communication Hole Design for Alignment Tolerance
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Solution Overview
Problem
The miniaturization of channels and decreased pitch in head chips for inkjet printers lead to reduced tolerance in displacement between the actuator plate and the nozzle plate, resulting in deteriorated ejection characteristics and ink leakage, particularly due to challenges in bonding and processing of intermediate plates with communication holes.
Innovation Solution
The design ensures a larger dimension in the second direction of the first opening part compared to the second direction of the second opening part to maintain bonding area and strength between the intermediate and actuator plates, allowing for miniaturization and reduced pitch while ensuring alignment and durability, and incorporates a configuration where the penetrating part is shorter in the third direction to prevent damage to the actuator plate during processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the communication holes are made larger to decrease alignment accuracy requirements, then the tolerance of displacement between channels and nozzle holes increases, but the bonding area between intermediate plate and actuator plate decreases
Solution Approach 1:
The communication hole is divided into two distinct parts: a first opening part that bonds to the actuator plate and a second opening part that aligns with the channel. This segmentation allows each part to be optimized independently - the first opening part maintains sufficient size for bonding while the second opening part provides the necessary alignment tolerance
Solution Approach 2:
Different regions of the communication hole are given different dimensional characteristics. The first opening part has dimensions optimized for bonding stability, while the second opening part has dimensions optimized for alignment tolerance. This local differentiation resolves the contradiction between bonding area and alignment accuracy
2Manufacturing precision
If the intermediate plate is processed to form communication holes after bonding, then the alignment between communication holes and channels improves, but the bonding surface of the actuator plate may be damaged
Solution Approach 1:
The bonding between the intermediate plate and actuator plate is performed in advance, establishing a stable foundation. The communication holes are then formed through the already-bonded intermediate plate using methods that confine processing damage to the intermediate plate itself, protecting the actuator plate bonding surface
Solution Approach 2:
The intermediate plate serves as a mediator that absorbs the mechanical stress and damage from the hole-forming process. By performing processing on the intermediate plate rather than the actuator plate, the bonding surface integrity is preserved while still achieving precise alignment through the intermediate plate's communication holes
3Measurement precision
If channels are miniaturized and pitch is decreased to increase resolution, then the ejection characteristics improve, but the tolerance of displacement between actuator plate and nozzle plate decreases
Solution Approach 1:
The intermediate plate with communication holes acts as an intermediary layer between the actuator plate and nozzle plate. This intermediary structure provides an additional degree of freedom for alignment compensation, allowing miniaturized channels to maintain both high resolution and adequate displacement tolerance through the communication hole's dimensional design
Data Source
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AI summary
A head chip, a liquid jet head, a liquid jet recording device, and a method of manufacturing a head chip each capable of ensuring the tolerance of the displacement between nozzle holes and communication holes while ensuring the bonding area between an actuator plate and an intermediate plate are provided. The head chip according to an aspect of the present disclosure includes an actuator plate, a nozzle plate disposed so as to be opposed to the actuator plate, and an intermediate plate disposed between the actuator plate and the nozzle plate. The communication holes each include a groove part having a lower-side opening part opening toward the nozzle hole, and a penetrating part having an upper-side opening part opening toward an ejection channel. A dimension in the X direction in the upper-side opening part is larger than a dimension in the X direction in the upper-side opening part, and a dimension in the X direction in the upper-side opening part is no larger than a dimension in the X direction of the channel opening part opening on a channel opening surface of the ejection channel.