Copper deposition is an autocatalyzed redox reaction that allows deposition on non-conductive substrates. The role of copper deposition is to realize the hole metallization, so that the double-sided board, multilayer board to achieve the interconnection between layers. Copper sinking is suitable for printed circuit board hole metal chemical coppering, also suitable for iron, steel, stainless steel, zinc and copper alloy surface chemical coppering, also suitable for ceramic copper plating, glass copper plating, resin copper plating, plastic copper plating, diamond copper plating, leaf copper plating and so on.
Copper immersion process equipment:
Desmear, PTH and PP three-in-one automatic production line.
Copper immersion process operation safety matters:
1. When adding the potion operation, you must wear acid and alkali resistant rubber gloves, gas masks, protective eye masks, protective masks, acid and alkali resistant work shoes, work aprons and other appropriate safety and labor protection products.
2. The discharge of potion should be treated accordingly, and the recycling should be recycled to make full use of the renewable resources and to meet the national emission standard at the same time.
3. The air in the copper sink contains NO, NO2, HCHO and other irritating toxic gases, the workshop staff should wear the appropriate labor protection equipment, and the workshop pumping should be turned on all day.
4. Always check whether the level of medicine is normal (in accordance with the indication of liquid level in the tank).
5. Pay attention to the temperature indication on the control panel and whether the filtration circulating pump is normal.
6. Every time before starting the copper sinking line, the first cylinder first do board start, if a long period of time to do board, in the resumption of production need to do the first false board drag cylinder.
7. The copper sinking cylinder must be pumped frequently, and all the liquid cylinders must be kept clean to avoid dust and other pollution.
8. Pay special attention to the backlight test in the production, found that the backlight is not normal, immediately analyze and adjust.
9. Frequently check whether the swing, automatic dosing, regeneration device, fire cow, etc. are running well.
Steps of copper sinking process: including the following steps
1. Treatment before copper sinking
2. Activation treatment;
3. Chemical copper sinking.
Copper immersion process of copper immersion before the treatment:
1. Deburring: copper immersion before the substrate through the drilling process, this process is prone to produce burrs, it is the most important hidden trouble caused by poor-quality holes metallization. Deburring process must be used to solve the problem. Usually use mechanical methods, so that the hole edge and the inner hole wall without barbs or blocking the hole phenomenon.
2. In addition to oil:
(1) the source of oil contamination: the drill bit due to hand contact caused by oil contamination, take the substrate when the handprints and other.
(2) the type of oil: animal and plant fats, minerals and so on. The former belongs to the saponified oil; the latter belongs to the non-saponified oil.
(3) the characteristics of grease: animal and plant oils and fats belong to the saponification of oils and oils are mainly composed of high-level fatty acids, which reacts with alkali to generate water-soluble fatty acid salts and glycerol; mineral oils and fats, the chemical structure of which is mainly paraffinic hydrocarbons, olefinic hydrocarbons and cycloalkanic hydrocarbons and chlorides, insoluble in water and do not react with alkali.
(4) Degreasing treatment method selection based on: according to the nature of oil, according to the degree of oil contamination.
(5) Methods: Organic solvents and chemical and electrochemical alkaline oil removal.
(6) Role and principle: □ saponifiable oil and alkaline chemical reaction to generate water-soluble fatty acid salts and glycerol.
Reaction formula is as follows: (C17H35COO)3 ten 3NAOH3C17H35COONa+C2H5(OH)2
Non-saponifiable oils: mainly by surfactants such as OP emulsifiers, sodium dodecyl sulfate, sodium silicate and so on. There are two groups in the structure of these substances, one is hydrophobic; the other is hydrophilic. First of all, the emulsifier adsorbed on the boundary between oil and water, with hydrophobic groups and oil on the surface of the substrate to produce affinity, and hydrophilic groups pointing to the de-oiled liquid, water is a very strong polar molecules, resulting in the oil and the substrate surface gravity reduced by the de-oiled liquid convection, stirring, oil off the surface of the substrate, to achieve the ultimate goal of de-oiled.
3. Roughening treatment:
(1) Roughening purpose: mainly to ensure good bonding strength between the metal plating layer and the substrate.
(2) Roughening principle: to make the surface of the substrate to produce a slightly concave pit, in order to increase its surface contact area, and the copper layer to form a mechanical button combination, to obtain a high bonding strength.
(3) Roughening methods and options: there are basically the following methods, mainly play a role in acid etching and strong oxidation.
A ammonium persulfate a sodium persulfate a copper chloride solution a hydrogen peroxide / sulfuric acid.
