PCB News - The difference between hdi circuit board browning and blackening

The difference between hdi circuit board browning and blackening

PCB manufacturers know that there are many procedures in the production of HDI circuit boards from the planned feeding to the last step. One of the processes is called browning. Some people may ask what is the role of browning? What is the difference between it and blackening? Today, the editor of Shenzhen Zhongke Circuit Technology Co., Ltd. (hdi circuit board/soft-hard combined board) will take you to find this answer.
The browning and blackening in the hdi circuit board manufacturing process are both to increase the bonding force between the original board and the PP. If the browning is not good, it will cause the oxidation surface of the hdi circuit board to delaminate, the inner layer is not etched cleanly, and the problems such as infiltration plating.
The function of hdi circuit board browning has the following three aspects:
1. Remove grease and debris on the surface to ensure the cleanliness of the board;
2. After browning, it must be pressed within a certain period of time to prevent the browning layer from absorbing water, which may cause the board to burst;
3. After browning, make the copper surface of the substrate have a layer of uniform fluff, thereby increasing the bonding force of the PCB substrate and PP, and avoiding problems such as delamination and explosion.

The difference between hdi circuit board browning and blackening has the following two major points:
1. The similarities between browning and blackening of hdi circuit boards:
A. Increase the contact area between the copper foil and the resin, and increase the bonding force between the two;
B. Increase the wettability between the copper surface and the flowing resin, so that the resin can flow into the dead corners and have stronger adhesion after hardening;
C. A fine passivation layer is formed on the copper surface to prevent the hardener and copper from reacting to produce water under high temperature and high pressure conditions to cause plate explosion.
2. The difference between hdi circuit board browning and blackening:
1. The thickness of blackened fluff is different from that of browned fluff;
2. Blackening syrup is more difficult to control than browning syrup;
3. The blackening potion is more expensive than the browning potion in terms of price;
4. The micro-erosion rate of the blackening potion is greater than that of the browning potion;
5. In terms of quality: the surface roughness of the blackened hdi circuit board is relatively large. If the inner layer of the circuit is slightly scratched or patched, the blackening can cover it well, but the browning will not work.
To sum up, this is the difference between browning and blackening of hdi circuit boards. How about, have you learned another little knowledge?