For such design problems, in the case of ensuring that the design manuscript is not changed, the parameters of the copper sink and the board can be appropriately adjusted to ensure that the copper thickness at the A is sufficient to avoid opening the copper in the subsequent process.
The main method can extend the original copper-plating time or after the completion of a copper sinking, the plate is again poured into the copper from the prepreg cylinder to ensure the thickness of the copper layer; and after a copper sinking, the small current is short (8ASF*). 30min) After the board is powered, the copper is again poured from the degreasing cylinder into the board, and then the hole copper is thickened enough in the board; in addition, the board current density can be appropriately reduced under the condition of the copper sinking condition. Extend the plating time to ensure that the copper ions in the hole are sufficient and the plating is uniform.
The production operation class causes no metal in the PTH hole to be mainly equipment abnormality and illegal operation. The slicing characteristics mainly include residual foreign matter in the hole, defects in the hole, electric copper wrapping plate, electric copper, etc.
The metal in the hole caused by the production operation is mainly caused by the deburring of PTH and the activation of the copper-cylinder equipment during the PTH process. The main abnormalities are: the high-pressure water washing abnormality after the PTH deburring stage, resulting in the drill copper powder in the hole. When the foreign matter cannot be discharged in time, the syrup in the hole cannot be exchanged normally during the subsequent PTH process, resulting in poor copper sinking in the hole; in addition, during the PTH process, the vibration and the gas cap in the activation cylinder and the copper sink are abnormally stopped or the vibration amplitude is abnormal. If the frequency is unqualified, the bubbles in the hole will not be discharged in time, affecting the exchange of the syrup in the hole, resulting in abnormal copper deposit, resulting in no metal defects in the hole.
For high aspect ratio products, it is important to ensure that the equipment is in normal working condition during PTH and pre-deburring. In addition, for such deep-hole plating products, the process parameters are changed to ensure clean and sufficient syrup exchange.
In the pre-treatment deburring, an additional high-pressure rocking water washing can be performed after a normal burr, and the product hole can be cleaned again; in addition, the electric amplitude of the PTH activation cylinder and the copper sink cylinder can be appropriately increased when processing the high aspect ratio product, The original 2.5m/s is increased to 3m/s to ensure that no bubbles remain in the pores during the PTH process.
to sum up
For deep hole plating products, the thickness of the plate is thicker, the aperture is smaller, and the aspect ratio is high. In order to ensure that there are no metal defects in the hole during the PTH process, the equipment, process parameters and process flow should be properly adjusted to ensure the hole. Internal PTH quality. The specific measures are as follows:
A. After deburring the PTH, perform another high-pressure rocking wash to remove foreign matter such as drill cuttings in the hole.
B. During the PTH process, the parameters of each cylinder, especially the activated and immersed copper syrup, and the thermometer are guaranteed to be within the normal process range.
C. During the PTH process, the electrical amplitude of the activation cylinder and the sinking copper cylinder are appropriately increased from the original 2.5m/s to 3m/s.
D. After a PTH, the plate is again fed into the plate from the prepreg cylinder, and the copper is additionally deposited once; or after the PTH is once, the plate is plated with 8NSF 8NIN and then the copper is again plated from the degreasing cylinder; the copper layer uniformity in the hole is ensured.
E. PTH rear panel power needs to use a small current for a long time to ensure that the copper ions in the hole are sufficient to ensure the plating effect of the hole wall.