The difference between HDI PCB browning and blackening

The difference between HDI PCB browning and blackening has the following two major points:
1. The similarities between HDI PCB browning and blackening:

(1)Increase the contact area between the copper foil and the resin, and increase the bonding force between the two.

(2)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;

(3)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 PCB browning and blackening:

(1)The thickness of blackened fluff is different from that of browned fluff;

(2)The micro-erosion rate of the blackening potion is greater than that of the browning potion;

(3)The blackening potion is more expensive than the browning potion in terms of price;

(4)Blackening syrup is more difficult to control than browning syrup;

(5)In terms of quality: the surface roughness of the blackened 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.