A blackening agent for the inner layer of a printed circuit board multilayer board and its preparation method and application

Abstract

The invention discloses a blackening agent for the inner layer of a printed circuit board multilayer board, a preparation method and application thereof. The blackening agent for the inner layer of a printed circuit board multilayer board, its raw material components are calculated by per kilogram of raw materials, consisting of 300~400g of sodium hydroxide, 200~300g of sodium chlorite, 5~15g of It consists of stabilizer, 0.005-0.01g wetting agent and water. Its preparation method is to completely dissolve the solid drug with water, then add a wetting agent until it is completely dissolved, and then add water to the calculated amount to finally obtain a blackening agent for the inner layer of a printed circuit board multilayer board. The obtained blackening agent for the inner layer of the printed circuit board multilayer board can oxidize the copper surface of the inner layer of the printed circuit board multilayer board into a dense oxide layer, thereby combining with the resin to form a large bonding force to avoid circuit Layering of boards. It also improves the unevenness of black oxidation, makes the black oxide layer denser, improves the anti-stripping strength, and the copper surface after micro-etching is cleaner and more uniform.

Description

technical field [0001] The invention relates to the surface treatment of metal materials, in particular to a blackening agent for the inner layer of a printed circuit board multilayer board and its preparation method and application. Background technique [0002] In the production process of multilayer printed circuit boards, due to the inconsistent thermal expansion coefficients of copper foil and resin, if the bonding force between the two is not enough when heated, it is easy to cause delamination at the interface. Therefore, the copper surface needs to be surface treated before lamination. , The more popular process at this stage is black oxidation treatment. The black oxidation process is a key technology in the manufacture of multilayer printed circuit boards. Among them, black oxidation is the key step of the whole blackening line process; the purpose of black oxidation is to form a uniform and dense needle-shaped oxide crystal layer on the copper surface, which inc...

AI Technical Summary

Problems solved by technology

This product has poor buffering capacity and high alkalinity, which is not conducive to the control of the pH of the potion. Poor pH control will directly lead to the loose structure of the formed black oxide layer. Usually, the micro-etching rate is maintained at about 1.3 μm / min

At the same time, it is easy to break when combined with resin, resulting in low peel strength, usually only maintained between 4.5 and 5.0 Lb / in; in addition, the copper surface after treatment is prone to unevenness