Electronic shall be a qualified electronic yarn after the beginning of the twisting process of manufacture. Then, it experiences the classification of the weaving process, being shafted with sizing, jet weaving, heat cleaning and surface chemical treatment process, finally becoming a qualified electronic cloth. The process for what has been listed, has strict limits of temperature and humidity.
Confirmed by many years of production practice, there is the proper scope of temperature and relative humidity of each process in workshop: temperature of twisting process within 26 to 30 ℃, relative humidity for (40 to 50) %. Weaving temperature within 23 to 27 ℃, relative humidity for (58 to 66) %. Cloth inspection process temperature within 26 to 30 ℃, relative humidity for (47 to 57) %.
Strict control for temperature and humidity of airflow, makes the standard deviation of a G – 75 electronic yarn reach to 0. 3161, the inner irregularity to 0. 4482%, and the deviation rate of per unit area of 7628 electronic cloth reach to more 1. 80%, or less 1.8% than before . This is better than JIS of Japan industrial standard, getting to the second standard of American IPC and the quality gets access to international advanced level.
Thickness tolerance of PCB, has a direct impact on the accuracy for the socket. The size of the tolerance of thickness, mainly depends on the deviation rate of per unit area of electronic cloth, i.e. single precision. In recent years, higher request for precision and uniformity of electronic cloth, has been put forward due to the development that requires high density, high performance, top layer and micro hole, light-weight of printed circuit board. It requires not only the uniform thickness of each paragraph of the whole cloth, but uniform thickness of each vertical and horizontal point of the whole cloth. The quality requirements of high uniformity, will only be achieved through the strict process control.
To some extent, therefore, air flow control is the guarantee for inner quality of electronic cloth, and the strict temperature and humidity control provides good technological conditions for the quality of appearance of the electronic cloth. Because strict temperature and humidity control of yarn in the process of each working procedure, prevents electronic yarn from producing hairiness in the early twisting process, makes the weft yarn equip with stiffness needed by the technology, and obtains the characteristic of fly in weaving process, which diminishes hairiness to get a smooth and clean cloth. All of these ensure that it will not produce the defects of appearance such as micelle, caused by hairiness while copper clad manufacturers glue on cloth, not make printed circuit board warp.
To sum up, the airflow control in the forming area, the temperature and humidity control in the process of textile processing, are indeed important technological conditions of high quality and high yarn in the industry.