The applications of inkjet technology in printed circuit board 1
Printed circuit board (PCB) initially started making process is to print circuit board type, but later because the resolution requirements for line increase, while the printing process can not meet, so the lines changed to high-resolution photolithography process replaced. However, the improvement of printing technology in recent years, some advanced printing such as ink-jet (InkJetPrinting), Screen Printing (ScreenPrinting), offset printing (FlexographyPrinting) and printed (GravurePrinting), the resolution can be printed line by the hundreds of um upgraded to make use of printing for hundreds of um line of production regained. Repeatedly stressed in recent years, green printing process is another try for the reasons discussed widely, because the use of printing can reduce the circuit production process of waste materials, and process steps can be reduced to save energy and reduce waste. Printing technology has the following advantages.
1. Manufacturing process steps to reduce: the circuit board can be made on line photoresist, exposure, development, etching and resist stripping steps reduced, replaced by printed photoresist, conductor lines and insulating material on the substrate, eliminating the negatives and the use of work mask.
2. Material use reduction: to reduce photoresist, developer, etching and stripping liquid film former such as the use of chemicals, but also exempt from the process waste and waste treatment.
3. Conversion process is easy: You can directly digitized by the computer directly to the line to be printed on the substrate, no longer prepared to meet the different product set and the mold and light equipment.
4. Thinning line: yellow line process of PCB manufacturing capacity of L / S = 3mil/3mil, R & D capabilities to 2mil/2mil, if the printed circuit materials and equipment with good resolution can be achieved 1mil/1mil.
5. Low-cost process: to reduce photoresist, developer, etching and stripping liquid film former such as the use of chemicals, reduce material costs, because the process steps also reduce the use of space can also increase plant flexibility.
PCB ink-jet technology to create an instance as an example when the EPSON, EPSON original use of inkjet technology improvements, there are CBIT (Circuit Board InnovationbyI nkJet Technology), through its production of inkjet machine with metal conductors and insulating material on the PI to ten laminates, selected as the basis for the first target COF.
Second, market overview
Inkjet technology used in production lines to the success of PCB production line, impact factor were the process, cost, materials were observed.
Process: continuous inkjet technology is still in development, PCB is the need to quickly produce a large number of industries, so the production speed and ink-jet technology can yield the same process with the existing yellow, or would affect the possibility of better replace the photolithography process to become the future mainstream of reasons.
Cost: As inkjet technology is still evolving, the current cost of materials and equipment are quite high, so the cost of materials and equipment are high, the future can be reduced by how much will that affect its ability to enter the mainstream market reasons one.
Material: Conductive inks can achieve a good match with the equipment, including viscosity / flow and molecular weight, will not block the inkjet head, conductive nano-metal conductor ink formulation, the material has been commercialized Ag using silver-based materials because the oxidation of copper is also necessary to overcome the problem. But silver is precious metals, high prices, can reduce the cost or the development of nano copper conductive paste will be the focus.
Because the material is made from metal powder slurry, after the inkjet line to go through sintering, but also because of other substances mixed with the metal powder slurry evenly distributed, so that the sintered conductor lines have a problem with impedance Therefore, the line too small electrical conduction problems arise, it is also for this reason can only be used in the early fine lines generally did not focus on home appliances with a single / double panel based.
Because all of these restrictions, PCB manufacturers discourage the use of inkjet technology, but also to the development of inkjet technology in the market, highly opaque information, blocking the interest of inkjet technology vendors want to try put, it is expected in 2012, IEK Only a few companies before using inkjet technology used in the PCB, screen printing, photoresist, and to mark the PCB on the other components of the position. Fabricated using inkjet technology for research and development and only limited prototype production, and the successful development of very few manufacturers really want to be able to IJP conductive lines for the production of products to line width from 70um ~ 100um single, Soft-sided main board and hard board, more than 100um line products will consider the cost of screen printing technology for production, so inkjet technology to manufacture PCB market growth is rather slow. Estimated 2012 global use of inkjet technology used in the production of conductive circuit board on the market size could reach 0.09 million, in 2013 the market size could reach 0.5 million, in Figure 1. 2012? Most of the companies is only just to test products, not mass production. 2013 on the circuit board industry, inkjet technology is still only a trial of new technology, can have a chance in 2013 after a wide circuit board into the application, still need to rely on material properties, material and equipment costs and the head of the able to produce and set the line width.
Third, the investment element of inkjet line substrate
PCB manufacturers are willing to ink-jet technology for PCB production, business strategies need to account for the firm, and the ink-jet technology itself material, equipment development.