The difference and function of HDI circuit board browning and blackening

There are many procedures for HDI circuit boards from project feeding to the last step. One of the processes is called browning. Today I will tell you about browning and its functions, as well as the difference and function of blackening.

1. The similarities between browning and blackening of HDI circuit boards: A. Enlarging the contact area between copper and epoxy resin to increase the bonding between the two; The lubricity between the two enables the epoxy resin to be injected into each blind area and has stronger adhesion after curing; C. A fine passivation layer is formed on the copper surface to avoid sealing the curing agent and copper under the condition of ultra-high pressure and high temperature Under the reaction to form water and cause explosion.

2. The difference between browning and blackening of HDI circuit boards: 1. The thickness of blackened plush and browned fluff is different; 2. The blackening potion is more difficult to supervise than browning potion; 3. The blackening potion is more brown The price of the chemical solution will be very expensive; 4. The micro-etching rate of the blackening solution is higher than that of the browning solution; 5. Quality level: the surface roughness of the blackened HDI circuit board is relatively large, if the inner layer route When the line is slightly scratched or repaired, the blackening can be covered very well, but the browning is not good.