Heat Shield for Printing Head on Heated Substrates
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Solution Overview
Problem
Non-contact deposition printing systems face issues with overheating of the nozzle plate and condensation of fumes on the printing head when depositing materials on a hot substrate, which affects the quality of printing in applications like solar cell production.
Innovation Solution
A heat shield is coupled to the printing head to prevent overheating and fume condensation, with a coolant-circulated shield frame and air flow induction between the shield and the printing head to manage heat and fumes, allowing for safe operation on heated substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the substrate is heated to enable material deposition, then the printing process can proceed, but the nozzle plate overheats and printing quality deteriorates
Solution Approach 1:
The system is divided into distinct thermal zones: the substrate remains heated for deposition, while the nozzle plate is isolated and actively cooled. The shield structure segments the thermal environment, allowing the substrate to be hot without transferring heat to the nozzle plate, thus maintaining printing quality while enabling substrate heating.
Solution Approach 2:
A shield structure acts as an intermediary between the heated substrate and the nozzle plate. This shield prevents direct thermal contact and heat transfer, allowing the substrate to maintain high temperature for deposition while the nozzle plate remains cool through active cooling, thereby resolving the contradiction between substrate heating and printing quality.
2Temperature
If the substrate is heated to facilitate deposition, then the printing process can continue, but fumes condense on the printing head and affect operation
Solution Approach 1:
The shield structure serves as an intermediary that blocks fumes from reaching the printing head. By positioning the shield between the heated substrate (source of fumes) and the printing head, it prevents fume condensation on critical components while allowing the substrate to remain heated for continuous deposition.
Solution Approach 2:
The harmful fumes are extracted from the vicinity of the printing head by the shield structure, which directs or contains them away from the nozzle plate. This separation removes the harmful condensation effect from the printing head while maintaining the heated substrate environment needed for deposition.
3Reliability
If active cooling is applied to the shield frame, then the printing head is protected from overheating, but the device complexity increases
Solution Approach 1:
The shield frame incorporates fluid cooling channels that circulate coolant to actively remove heat. This hydraulic cooling system provides reliable temperature control for the printing head by conducting heat away through the shield frame, balancing the need for temperature control with a practical cooling implementation.
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 solution effectively prevents overheating of the printing head and inhibits fume condensation, ensuring consistent and high-quality printing on heated substrates by maintaining a controlled environment and air flow, thereby enhancing the reliability of non-contact deposition processes.
Implementation Method 1
Water or another coolant may be circulated through the shield frame so as to remove heat from the shield frame and plate
Implementation Method 2
The air flow in between the shield and the printing head may exit through the slot and may push away hot air from the substrate that would otherwise enter through the slot in the direction of the printing head
Implementation Method 3
fumes evaporating from the liquid material dispensed onto the heated substrate
Implementation Method 4
the fumes may condense onto the nozzle plate in the form of droplets
Data Source
Figure 1~2
Figure 3~4
AI summary
A printing device for dispending material on a heated substrate is provided. The device may include a printing head having one or more nozzles and a heat shield that partially masks a side of the printing head that faces the heated substrate when printing so as to reduce heat transfer from the substrate to the printing head. The shield includes a slot aligned with the one or more nozzles to enable passage of material from the one or more nozzles to the heated substrate.