The Research To The Function Of Organic Chemical Additive In Printed Circuit Board Copper-plating And Technology

Good quality copper is deposited on epoxy resin substrate using electroless plating method. A kind of copper plating technique using two complexing agents is developed with appropriate deposition rate and good stability. The new multi-component organic chemical additives have been developed and suitable formula of new multi-component organic chemical additives have been obtained through analysising several kinds of organic electrocoppering chemical additives. It probably substitute the overseas import dye.The craft of chemistry copper-plating has also been studied. The working procedures' formula and operating condition have been obtained of eliminating, coarsening and activating. It has been inspected the condition such as cupric sulfate concentration, the organic additive concentration, the formaldehyde concentration, the complex agent content on the influence of the polarization curve. The results of the experiment have showed that the concentration of cupric sulfate, the content of formaldehyde and the complex agent, the ratio of organic additive, the acidity and the temperature have influence on the speed of chemistry sinking copper ,stability of plating solution and coating performance. The proper technology is as follows: CuSO₄·5H₂O: 16g/L, EDTA·2Na: 20g/L, TART·KNa: 14g/L, NaOH: 15g/L, HCHO (37%) : 15ml/L, BO2: 0.012ml/L, pH: 12.5,T: 45℃, Agitation: 60r/min. It has analysised the effect of the experimental factor on the electrocoppering. Suitable formula of organic chemical additives have been obtained through the orthogonal experiment. The effect of the concentration of domestic dye, the import dye and the assembles organic additives by oneself on cathode polarization curve has been inspected, the assembles chemical organic additives by oneself can increase the cathode polarization, which is similar with the overseas dye polarization curve. Through the experiments of the electrocoppering, it found out the proper conditions as following: CuSO₄·5H₂O: 100g/L, H₂SO4: 200g/L, organic additives:FO4 0.02g/L;CO1 0.02ml/L;MO1 0.04g/L;CO3 0.03ml/L;CO4 0.01ml/L; DO1 0.6ml/L;TO5 0.12g/L;NaCl 60mg/L, I (A/dm²) : 5,T: room temperature, agitation way: air agitation. The stability of electroless copper plating solution can be increased by using two complexing agents and stabilizer, and the deposition velocity can be kept at medium level. The results of experiments showed that the plating is dense, even and well adhered to the substrate. It can be applied to printed circuit board(PCB).Hull trough test and TEM analysis indicated that covering power of plating solution improved, crystallite of plating is careful, luminous area is increased when we added the assembles chemical organic additives by oneself in the electrocoppering. It can nearly achieve the overseas dye's effect.