Surface Treatment Process of Soft Board FPC Production
Surface Treatment Process of Soft Board (FPC) Production
In the electronics industry is growing today, with the electronic products to light, thin, short trend, high-performance and multi-functional development and improvement of electronic components welding technology, flexible circuit board (FPC) as the same for electronic Even the circuit board has been in the past two years in China PCB industry to the rapid development of electronic products due to light, thin, short of demand, the application of soft PCB more and more widely, flexible PCB and other types of printing Plate, a lot of wiring in a small space, the need to repeatedly bend the site due to the selection of special materials, compared to other cables have a longer bending life.
Because of the characteristics of light and thin, the surface of the soft board in the processing of surface treatment of machinery and equipment and processing methods have their special requirements, the production of soft board, surface cleaning is a key link, because it requires not only the surface Dimensional stability of the plate depends on the dimensional stability of copper foil laminated layer of the rate of change, but also with the production process has a great impact on mechanical grinding, grinding brush roller running direction and board transfer In the opposite direction, is to ensure uniform grinding effect, but the soft substrate thin and soft substrate, grinding too much pressure on the substrate will be subject to great tension and elongated or snapped, which is caused by size changes in one of the important reasons, grinding The process should avoid the substrate scratches, tear and pallets, if the equipment is not specialized in the production of soft board conditions, the proposed use of pallets, so as to avoid the machine drive wheel spacing, high pressure washing rinse and drying hot air The impact of deformation caused by substrate pallets, or even scrapped.
According to the requirements of the soft board production process and abrasive grinding wheel grinding comparison, the use of chemical cleaning process in the production of flexible printed circuit and nylon needle brush roller is a pattern transfer, hole metallization and paste coating process surface The ideal choice of treatment, both to remove the copper oxide layer can do board with good roughness.
In the chemical immersion gold and other surface processing technology before the treatment, you can choose low-power non-woven brush roller, because of its uniform and detailed grinding effect, to ensure removal of residual plastic plate, the pad evenly grinding treatment, which is nylon Needle brush can not reach the surface treatment effect, because of its soft pad generally small and small pads, ordinary nylon needle brush can not be completely ground to the pad, and grinding will leave strip-like scratches, welding and surface Beautiful. Non-woven brush roller can improve the effect which can not be achieved by the nylon needle brush. The non-woven brush roller is the first choice for many manufacturers of high-precision circuit board because of its uniform and fine grinding effect. It is recommended to use brush roller surface Hardness of 30-45 degrees 1000 # +1200 # red non-woven brush roller with the use of wear marks control in the 8-10mm, can ensure that the dirt pad to remove the surface coating formation.
The surface of the soft plate is cleaned and polished before the hole metallization to improve the bonding strength between the plated layer and the substrate, and the copper surface is effectively treated before the patterning of the hole metallization image. For the enhanced copper foil and the anti- The adhesion strength of the etching layer is also very important, FPC plate metallization of the surface before the untreated clean, hole metallization coating layer may occur, blister phenomenon, the image before the copper surface cleaning and roughening is not enough, and the resist layer Of the combination is not enough, the production of fine line pattern in the back plating process prone to seepage plating, short circuit defects, resulting in board scrap.
In the hole metallization and pattern transfer before the CCL surface roughening method, it is recommended to use alumina abrasive 800 # +1200 # nylon needle brush roller, not only can effectively remove the copper particles, and can be effective for the copper surface rough The effect of wear control, wear marks control in the 8-12mm, can effectively prevent the coiling and grinding over the board caused by elongated and other issues, with alumina abrasive nylon needle wire in the treatment of copper surface, the cutting force than the traditional silicon carbide abrasive to small , Can reduce the scratches board scratches, the more dense the more fine scratches, the board with the combination of the resistivity of the better, in the back of the paste when the paste we recommend using wet film to enhance the board with the same The adhesion of the resist layer.
Chemical cleaning method is to remove the surface of organic chemicals and organic pollutants, and then use the micro-etching solution on the surface roughing treatment after the surface of the copper plate has a good flatness, and there is no mechanical scratch and The residual abrasive particles, and therefore the fine wire printed circuit board processing ideal cleaning rough surface treatment method, but this method in the removal of copper foil surface is not easy to complete the copper particles and foreign objects for leveling, easy oxidation, rough The degree of mechanical grinding effect is not good, suitable for covering the film before the paste treatment process.
Soft PCB as the domestic rapid growth of the industry, many materials and equipment still need to continue to explore, the need for mass production of machinery and equipment, materials, the field of continuous integrity, this paper draws a link from the impact of soft board quality Of the factors discussed, only to master the essentials of all aspects of production in order to produce higher performance and more reliable, more beautiful appearance of the product, the growing soft PCB industry in China.