A comprehensive look at how dispensing technologies like XTPL’s UPD process and aerosol printing measure up in terms of precision, materials, and applications.
A comprehensive look at how dispensing technologies like XTPL’s UPD process and aerosol printing measure up in terms of precision, materials, and applications.
Today, there are a range of different precision fabrication technologies used in the production of printed electronics, including screen printing, inkjet printing, direct-write dispensing, and aerosol printing. While they differ in terms of their deposition methods, these processes have been integral to the production of advanced printed electronics, including miniaturized devices and flexible electronics.
In this article, we are homing in on two leading printed electronics processes, direct-write dispensing technology and aerosol printing, to understand how these approaches differ and where their respective strengths and weaknesses lie.
The Rise of Precision Fabrication Technologies
When it comes down to it, the basic function of direct-write dispensing and aerosol printing are similar: they are both maskless processes built to selectively deposit materials, such as inks loaded with conductive nanoparticles, onto a substrate. These inks are patterned in traces that create functional circuits and sensors. As we’ll see, however, there are key differences between the two electronic printing techniques.
What is Dispensing Technology?
Dispensing technology, often called Direct Ink Writing (DIW), is a process that uses a fine nozzle and pressure system to selectively deposit a feedstock material onto a substrate. Similar to a printhead on an extrusion 3D printer, the nozzle, controlled by a stepper motor, moves over the substrate, dispensing lines or dots based on the design in a digital file (i.e. a Gerber file). As the name Direct Ink Writing suggests, it is almost as though the nozzle is writing on the substrate.
The dispensing process is the result of pressure which is applied to a cartridge of material. For example, there are pneumatic DIW systems that release controlled amounts of air pressure into a cartridge to deposit material, while others integrate a screw or auger to push the feedstock out of the nozzle.
Automated dispensing systems are typically able to dispense inks or pastes in a range of viscosities with a high level of precision. Up until recently, most dispensing platforms were limited in the resolutions they could achieve (in the realm of 100 µm), however recent advances have dramatically changed this. Specifically, XTPL’s Ultra Precise Dispensing (UPD) technology makes it possible to print traces as fine as 1 µm, though factors like feedstock material and printing speed can influence the overall print resolution.[1] In electronics printing, feedstock materials are filled with conductive nanoparticles, such as silver.
Benefits of Dispensing Technology
There are several benefits to using a direct dispensing system when it comes to manufacturing electronics, including:
- Very high resolution printing, in the range of 1 µm in some cases, which facilitates the miniaturization of sensors and electronic devices.
- Broad material versatility, including conductive and dielectric inks and pastes in a range of viscosities.
- Material use is highly economical, generating virtually no waste, which can reduce costs associated with expensive conductive inks. For instance, XTPL’s UPD process can print with only 0.5 ml of material to start.
- Compatible with a wide variety of substrates, including glass, silicon wafers, kapton, PEN, PC, PDMS, and PET.
- Technologies like XTPL’s UPD process can print on planar surfaces as well as on 2.5D surfaces, facilitating repairs.
- Multiple layers can be printed to create thicker and taller traces when necessary.
Applications for Dispensing Technology
Direct-write dispensing technologies have a number of applications in the field of printed electronics, especially when it comes to rapid prototyping, customized electronics, or low-volume manufacturing. Looking specifically at XTPL’s cutting-edge Ultra-Precise Dispensing, users can leverage the technology in the production of MicroLED displays, high-density interconnects (HDI), flexible electronics[2], and flexible hybrid electronics in sectors like automotive, healthtech, consumer electronics, and R&D.
Notably, XTPL’s dispensing solution also has applications in the repair of open defects for existing circuitry and PCBs. The technology can also deposit 3D interconnects within a circuit, even in the case of stacked chips.
What is Aerosol Printing?
Aerosol printing is another type of production process for printing electronics. Unlike dispensing systems that use a nozzle and pressure to deposit inks or paste, the aerosol technique atomizes conductive inks to create a fine microdroplet aerosol. The atomization is achieved using an ultrasonic or pneumatic atomizer (this varies depending on the system) and the microdroplets created in the process are then focused into a beam using a carrier gas and jetted from a fine nozzle at a high velocity, bonding to the substrate.
Like dispensing technology, aerosol jet printing is computer-controlled, meaning that the movement of the aerosol nozzle is determined by a digital CAD file. The technology also necessitates a curing process for the deposited ink to increase the conductivity. This can be done using conventional thermal treatments like sintering ovens. However, this process subjects substrates to high temperatures, which can be damaging if the sensor in question uses a low-temperature material as substrate. In these cases, a sintering laser is more suitable, as it selectively cures the conductive trace rather than the entire device. Certain aerosol printing systems, such as Optomec’s Aerosol Jet solution, can integrate laser sintering modules directly.[3]
The aerosol printing process also is notable for being non-contact, meaning that the printhead does not touch the substrate as the material is applied. This makes the application of conductive traces onto very thin (and even three-dimensional) substrates possible.
Benefits of Aerosol Printing
Aerosol printing brings with it a number of benefits, including:
- Very high resolution printing with the ability to deposit traces in the range of 10µm.
- Compatible with a range of substrates, including 2D planar 3D and non-planar surfaces, which opens up applications for flexible, conformal electronics.
- Non-contact process which limits the risks of substrate damage in the printing process, particularly when it comes to thin flexible substrates.
- Selective deposition of aerosol printing reduces material waste of costly conductive inks.
- Due to the atomized nature of the feedstock material, there is less risk of clogging the nozzle.
Applications for Aerosol Printing
In terms of applications, aerosol printing is highly versatile. As a non-contact technology, aerosol printing has the ability to precisely deposit conductive and dielectric traces onto very thin substrates, making possible the prototyping and production of flexible devices (such as wearable electronics), RFID antennas, thin-film transistors, and conformable biosensors.
Like dispensing and other maskless printing processes, aerosol printing is also highly suited to the rapid prototyping of electronics, since it can directly print devices without the need for stencils or tooling. From a developer’s perspective, this has enormous benefits in terms of being able to print, test, and adjust circuit designs with a rapid turnaround. Moreover, this makes the production of custom devices possible, as well as on-demand production for low-volume applications.
Considerations When Choosing an Electronics Printing Process
Ultimately, both dispensing technologies and aerosol printing systems present benefits and opportunities for printing electronics. Generally speaking, dispensing technologies are recognized for their relatively straightforward process (not requiring the use of special gases or atomizers) and their wide feedstock compatibility, including highly viscous pastes.
Interestingly, areas where aerosol printing had typically reigned, such as its very high resolution capabilities and ability to print on non-planar surfaces, are now being challenged by cutting-edge dispensing processes like XTPL’s UPD technology, which is capable of dispensing ultra-high-resolution traces onto planar and 2.5D surfaces.
Overall, both processes are versatile and can meet the requirements of various printed electronic applications. If you are interested in learning more about XTPL’s dispensing technology and how it is bridging the gap between the two processes, especially in terms of resolution, get in touch with a member of our team today.
Resources
[1] Ultra-Precise Dispensing. XTPL, 2025. https://xtpl.com/ultra-precise-dispensing/
[2] Roemhild M, Waldner K, Baur H, Fruehauf N. Process Considerations for Ultraprecise Deposition Printing on Flexible Substrates. In2024 IEEE International Flexible Electronics Technology Conference (IFETC) 2024 Sep 15 (pp. 1-3). IEEE.
[3] Aerosol Jet Printed Electronics Overview. Optomec, April 2014. https://www.optomec.com/wp-content/uploads/2014/04/AJ_Printed_Electronics_Overview_whitepaper.pdf
