The absence of metal defects in the PTH hole caused by the abnormality of the syrup is mainly manifested by the poor PTH in the star point of the hole, and the electric copper package plate copper in the defect area.
A. Insufficient palladium ion content in the activator, resulting in the formation of sufficient colloidal palladium on the surface of the substrate during the activation process. In the subsequent copper sinking process, the lack of palladium ion catalysis leads to poor copper in the pore wall, causing pores. No metal defects.
B. The microbubbles are infiltrated into the activation cylinder, causing the hydrolysis of the colloidal palladium in the cylinder, so that the activation cylinder loses its activation function, and the copper layer cannot be deposited in the pores.
C. The pH value in the solution is too low. Because the chemical copper sinking needs to be carried out under the conditions of strong decrement, the reduction ability of formaldehyde decreases when the pH is too low, which affects the reaction rate of copper precipitation, resulting in poor copper sinking.
D. Insufficient complexing agent in the copper sink cylinder, causing some copper ions to form copper hydroxide precipitate. There is not enough copper ions in the copper cylinder to react and deposit on the inner side of the hole wall, resulting in poor copper sinking.
In the PTH production process, for the activation cylinder and the immersion copper cylinder, it is necessary to ensure that the components in the cylinder are maintained within the normal process concentration range to ensure the orderly progress of the chemical reaction. In addition, the PH and temperature in the cylinder will also affect the effect of sinking copper on the inside of the hole wall and should be monitored continuously.
palladium in the activation cylinder is affected by fine bubbles, which is easy to produce hydrolysis. Therefore, it is necessary to ensure that there is no gas leakage in the cylinder pipe to ensure the normal reaction of the colloidal palladium.