Circuit board plasma cleaner

• Categories:Industry News
• Author:plasma cleaning machine-surface treatment equipment-CRF plasma machine-Sing Fung Intelligent Manufacturing
• Origin:
• Time of issue:2020-12-05
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(Summary description)PCB, especially high density interconnection boards, need to be metallized through the holes, so that the electrical conduction between the layers can be realized through metallized holes. Laser hole or mechanical hole due to the local high temperature of drilling, drilling after the residual gel is often attached to the hole. In order to avoid quality problems in the subsequent process, it must be removed before the next process. At present, the removal of drilling pollution mainly involves wet processes, such as potassium permanganate method. Due to the difficulty of liquid entering the hole, the removal of drilling pollution is limited. As a dry cleaning method, plasma cleaning machine solves this problem well.   Principle of plasma cleaning:   A plasma, also known as the fourth state of matter, is an electrically neutral ionization mass. The plasma gas must have several conditions: a certain degree of vacuum; The selected gas is supplied with a certain degree of vacuum. Turn on the RF power and apply a high voltage electric field to the electrodes in the vacuum to ionize the gas between the electrodes, generating a glow and forming a plasma. The plasma cleaning process in printed circuit board can be divided into three stages. One is the process of adsorbed the generated gas phase substances containing free radicals, electrons and molecular plasmas on the surface of the contaminated solid. Secondly, the adsorbed groups are reacted with the molecules on the surface of dirty solid to form molecular products, which is the process of analyzing the generated molecular products into gas phase. The third is the process of separating the reaction residue from the plasma.   Plasma hole cleaning:   Plasma hole cleaning is the primary application of printed circuit board. Oxygen and tetrafluorocarbons are usually mixed as the gas source. In order to obtain better treatment effect, controlling the proportion of gas is the determinant of plasma activity.   Plasma surface activation:   PTFE(polytetrafluoro-ethylene) materials are mainly used in microwave plates. The general FR-4 multilayer plate hole metallization process is difficult to achieve, mainly because of the activation process before chemical copper deposition. The existing wet treatment method is to use naphthalene sodium complex treatment solution to make PTFE surface atoms in the pore eroded, so as to achieve the purpose of wetting the pore wall. It is difficult to synthesize, toxic, and has a short shelf life. Plasma processing is a dry process, which solves these problems well.   Plasma removal residue:   Plasma removal is a good choice in PCB production. In the process of image transfer, the printed circuit board after sticking the dry film needs to be developed for plasma etching to remove the copper area that does not need to be treated. The process is to use the developer to dissolve the dry film that is not exposed. In the subsequent etching process, the dry film copper surface that is not exposed is etched. In this development process, often because of the development cylinder nozzle pressure is not uniform and other reasons, local unexposed dry film can not be completely dissolved, forming residue. This is more likely to occur in fine wire fabrication, resulting in a short circuit after subsequent etching. The residue can be well removed by plasma treatment. In addition, when the circuit board is mounted, areas such as BGA need to have a clean copper surface, and the residual copper will affect the reliability of welding. It is proved that this method is feasible and achieves the purpose of plasma cleaning by using air as air source.   Plasma treatment process is a dry process, compared with the wet process has many advantages, these advantages are determined by the characteristics of plasma itself. The whole reactive neutral plasma from high voltage ionization has a high degree of activity, and can continuously react with the atoms on the surface of the material, so that the surface material is constantly excited into gas, volatilization, in order to achieve the purpose of cleaning. It has good practicability in the process of printed circuit board production and is a clean, environmental friendly and efficient cleaning method.   Atmospheric injection plasma cleaning machine has the advantages of high cost performance, simple and convenient installation, can be installed on the assembly line and automatic equipment. So atmospheric jet plasma cleaning machine has been the preferred use of most enterprises plasma surface treatment equipment processing circuit board, according to the nozzle can be rotating different, atmospheric jet plasma cleaning machine can be divided into direct jet atmospheric jet cleaning machine and atmospheric jet rotary plasma cleaning machine two types.