Key Technology And Application Of Making Plug Holes And HDI Printed Circuit Board

The high density interconnect(HDI) technology, one of the most fashionable printed circuit board production technologies, is widely used in the fields such as communications, computer, consumer electronics products, aerospace, medical equipment etc. Its main technology is the production of fine lines and microvia. This paper is mainly focused on the production process of HDI fine lines and microvia. According to the experiment of the fine lines production process, the through holes and fine lines with simultaneous electroplating production process and plug holes production process, the main results were obtained as following:During the production of fine lines, the etching performances of semi-additive and improved semi-additive method are more excellent than subtractive method, which have more advantages in the production of fine lines. In the the production of fine lines study, L9(34)orthogonal arrangement was used to take the orthogonal experiment, the optimum subtractive method technique parameters were obtained in the study, the rate of developing is 4.0 m/min, the above and below pressure of the developing is 0.18 MPa and 0.15 MPa, respectively. The rate of etching is 4.5 m/min, the above and below pressure of etching is 0.28 MPa and 0.25 MPa, respectively.In the study of the through holes and fine lines with simultaneous electroplating production process, by taking reasonable control of drilling and hole cleaning, imaging transferring, electroless plating, Pattern Plating process etc. Through holes with thickness at 1.5 mm and diameter at 200 μm hole and fine lines with width and pitch both at 50μm were manufactured through simultaneous electroplating, the power of throwing is over 60%, and there exists binding force between fine lines and substrate. After comprehensive consideration of the throwing power of through holes, the binding force of fine lines and the brightness of plating, the optimum prescription of the electroplating liquid were obtained: the concentrations of CuSO4, H2SO4, additive a and b are 45g/L, 220g/L, 0.6ml/L and 20ml/L, respectively.As for plug holes production process, resin plug hole and prepreg direct plugging buried hole process were investigated, respectively. The resin plug hole process results demonstrated that the hole bubbles and residual moisture, the thermal expansion coefficient between the resin, the residual orifice resin and other problems would cause the thermal stability of HDI decreased, the delamination would happen under high temperature environment. The prepreg direct plugging buried hole process is simple, the buried hole is 100% full and the match between the resins is good. The thermal stability of HDI can be improved, but the problem of board surface depression would exist, which would be influenced by the diameter, depth and density of the buried hole, gel content, copper residual ratio of the board, lamination temperature and pressure atc.