Application
The polyimide films market has been segmented into FPC, specialty fabricated product, pressure sensitive tape, motor / generator and wire & cable. As per the findings of research, FPC held the largest share of the market in terms of both revenue and volume in 2016. Polyimide films are most preferred over other materials such as polycarbonates, epoxy resins, and polyurethanes, for manufacturing FPC owing to its blend of electrical, chemical, mechanical, and thermal properties.
Asia-Pacific held the largest share of the polyimide films market in terms of both revenue and volume in 2016. In Asia-Pacific, PI films are mostly consumed in semiconductor foundries and semiconductor component manufacturing facilities located in Taiwan, China and Japan. In addition, growing usage of PI films based electronics devices among users has created surge in demand for the polyimide films market.
How to make the polyimide film?
Preparation of monomers. The first step is to prepare the monomers, which are the building blocks of polyimide resin. The most common monomers used to make polyimide resin are diamines and dianhydrides. Diamines are compounds with two amino groups, while dianhydrides are compounds with two carboxylic acid groups.
Polycondensation reaction. The monomers are then reacted together in a polycondensation reaction to form poly(amic acid). This reaction is typically carried out in a solvent, such as dimethylformamide (DMF) or N,N-dimethylacetamide (DMAc).
Imidization. The poly(amic acid) is then imidized to form polyimide. This is done by heating the poly(amic acid) to a high temperature, typically in the range of 200-300 degrees Celsius. The imidization reaction is exothermic, so the temperature of the reaction must be controlled carefully.
Film formation. The polyimide can then be cast into a film. This is typically done by dissolving the polyimide in a solvent and then casting the solution onto a substrate. The solvent is then evaporated, leaving behind the polyimide film.
The following are some additional details about the process:
The choice of monomers will affect the properties of the resulting polyimide film. For example, the type of diamine used will affect the film’s thermal stability, while the type of dianhydride used will affect the film’s mechanical properties.
The polycondensation reaction can be carried out in either a solution or a melt phase. The solution phase is more common, as it is easier to control the reaction conditions.
The imidization reaction can be carried out in either a batch or a continuous process. The batch process is more common, but the continuous process is more efficient.
The film formation process can be carried out using a variety of methods, including casting, spin coating, and extrusion. The casting method is the most common, as it is relatively simple and inexpensive.
So far, the thermal decomposition temperature of our PI is 450°C, the long-term use temperature can reach more than 200°C, and the short-term use above 300°C is acceptable.