Heat Transfer Issues in Print-heads: Control and Applications

摘要

Thermal Control in MEMs is becoming a major subject. As the manufacturing capabilities increase and help design and build more complex structures, driving more power in smaller scale dimensions it becomes a must to harness the heat flows within the device. Sometimes, to enable a concrete function that precise, accurate heat transfer, other times just to ensure device and operation reliability. We will review the subject of heat transfer in MEMs in general and print/heads specifically. MEMs in general and thermal inkjet print-heads in particular have different functional layers and structures designed for its intended function. When considering control over the MEMs desired operation this puts a series of constraints on the dimensions and material properties of this layers that are discussed. Equally important is the degree of "intelligence" build up on the device itself has an impact on the capability for Thermal and Energy Control. Having more capability is an enabler of several features such as speed of operation but many times needs to be traded by cost. Discussion of current solutions such as sensors in the print-heads, firing pulse schemes, pulse width modulation and others are discussed in the paper. Last but not least it is increasingly important to take a global system perspective when designing for Thermal Control in MEMs since many of the times MEMs are meant to work within a system where other components act as important heat sources.