What is the relationship between the thickness of the polyimide film layer and the corona resistance

The interlayer thickness of the polyimide film is related to the corona resistance. Everyone knows this, but everyone is not too clear about the specific relationship. Here, we have invited a professional manufacturer to answer for us, come and take a look at the detailed introduction below.

Polyimide film

The corona resistance test was performed on five three-layer composite polyimide films with different thickness shares and Kapton 100 CR film. During the test, five samples of each film were taken for relatively independent experiments, and Wilbur was also adopted. Distribution function method for data processing. The corona resistance time of 5 groups of three-layer composite films can be obtained as 54.8 h, 57.9 h, 107.3 h, 92.6 h, 82.9 h, respectively, and the corona resistance time of Kapton 100 CR film can be obtained. For 48 h.

It can be seen that the corona resistance of the three-layer composite polyimide film with different doping thickness ratios of Keji’s five kinds are all greater than Kapton 100 CR. With the increase of the relative thickness of the doped polyimide layer, the three-layer composite The corona resistance of the polyimide film firstly increases and then decreases, and the three-layer thickness share d:d:d. =0.42:1:0.42 The three-layer composite polyimide film has the longest corona resistance time of 107.3 h, which is more than twice the corona resistance time of Kapton 100 CR under the same conditions.

According to the trap theory, after the introduction of nanoparticles into the polymer, a lot of trap structures will be formed inside the material. These traps can capture the carriers injected by the electrodes. The captured carriers will form a space charge electric field, which can not only hinder The further injection of carriers can also shorten the mean free path of the carriers, make the terminal velocity of the carriers smaller, and weaken the damage effect on the organic/inorganic phase interface structure. Followed by the thickness of the doped polyimide layer The increase in the share is equivalent to introducing more trap structures, increasing the hindering effect on carrier transfer, and improving the corona resistance of the three-layer composite polyimide film.

On the other hand, it can be seen from the analysis of the breakdown field strength above that as the thickness share of the doped polyimide layer increases, the distribution field strength of each layer increases. Therefore, as the thickness share of the doped polyimide layer increases , After the carriers enter the data, the greater the energy obtained due to the acceleration effect of the electric field, the greater the damage effect of the carriers on the data, and the carriers can also transfer energy in the process of collision, resulting in heat energy , It damages the internal chemical structure of the data, accelerates the aging and breakdown of the data, and reduces the corona resistance.

Based on the above two reasons, the corona resistance time of the three-layer composite polyimide film increases first and then decreases with the increase of the relative thickness of the doped polyimide layer. The thickness proportion should be appropriately selected so that The breakdown function and the corona resistance function have been appropriately improved.