Printing electronics is a group of ways or methods to print particular electric functions in electronic devices. In past, printed papers were used for indicating the functions of electric devices and this was due to their very small size. However, the drawback of this method was rough surface and high humidity absorption of paper. Afterwards, use of some other printing materials were started such as plastic, ceramics, and silicon.
Printing electronics is a technical way of printing using special ink and equipment having a high quality of printing. These methods are less expensive and the printing quality is comparatively superior. Several printing processes have been developed for printing electronics such as screen printing, flexography, offset lithography, gravure ,and inkjet. Now, optical inks are used in place of printing graphic arts inks.
Different Methods of printing small electronic components
The methods of printing different electronic devices such as ICs, transistors, and CPU are as follows.
The mass-printing methods are very famous in the market compared to other printing methods due to their enhanced productivity. Their throughout is up to 10.00m²/h, and hence, especially suitable for a dramatic reduction of fabrication costs. These methods are so well developed that that they allow for high resolution down to 20µm and below. They are used for high quality and for large achievable layer properties as well. Some of the most famous methods under mass-printing are given below.
- Rotogravure Printing
The principle of Rotogravure is similar to the intaglio printing process. This printing is based on engraving the image onto an image carrier. In this method, a copper cylinder is used as image carrier. Hence, we can say that this technology is based upon printing on a roll of paper rather than sheet of paper. It provides high layer quality; due to this, it is suitable for quality sensitive layers such as semiconductor and dielectric interfaces in transistors.
- Offset Printing
Offset printing is a very common technique in which the inked image is transferred from a plate to a rubber blanket. The image is then transferred to printing surface from that rubber blanket. However, the non-printing area uses a water-based film called fountain solution for keeping itself ink free.
This technology is used for printing inorganic and organic conductors. This is also used in computer to plate (CTP) printing technology.
- Flexography Printing
This is a process of printing in which a flexible relief plate is used, and this technique is an updated version of the letterpress. This method can be used for any type of substrate such as plastic, metallic films, cellophane, and paper.
For printing electronics, this method is better than offset printing and can be used for inorganic and organic conductors.
Inkjet Printing Method
Inkjet printing is the most common method of printing different electronic devices. This process is flexible and versatile as well. It can be
set up with comparatively low effort. It is poorer than mass printing methods due to its throughput and also in terms of resolution. This method provides throughput typically up to 100 m²/h and resolution down to50 µm.
This method is used for soluble materials, like organic semiconductors and high viscosity materials like organic dielectrics. This method provides limited homogeneity due to the drop-wise declaration of layers.
This method is also used for printing organic field effect transistors, and organic light emitting diodes. Some other devices such as front planes, integrated circuits, and back planes can be prepared by this method. However, printing in OFET is completely done by this method.
Screen Printing Method
This method has been used worldwide for many years due to its thick layer printing ability. This method is used for printing in circuit boards, antennas, and they are also used for printing insulating layers. Although it has the quality of printing with high layer thickness, but its throughput and resolution quality is bad compared to other methods. It gives throughout nearly 50m2/h and resolution is 100 µm. It’s a very simple method and used for printing conductive and dielectric layers.
The most important goal of printing electronics is to develop more and more technologies of printing small components, so that to make the work of printing easier. This part of electronic engineering is working on enhancing the quality of printing with comparatively low cost. This technology is actually very close to its goal; however, it still needs integration and optimization of many factors. It requires developing high quality ink for printing and high quality equipment design for handling the printing work.
Image: Printing Electronics- Flickr.com
Image:- gtai.com-Mass- Printing Method
Image:microfab.com– Ink Jet Printing Method-
Image: printingimpact.com-Screen Printing Method-
Referance: Image Processing & Computer Vision- A.K. Jain