As shown, since 1903, Albert Hansen pioneered the concept of "line" to 1936, Paul Eisner really invented PCB production technology, and then today, more than a hundred years have passed, it can be said that the production process of PCB has been very mature, even PCB multilayer board, is also the case (Note: According to the relevant literature, in 1964, China's Ministry of Electronics under the relevant units, has begun to study the production of PCB multilayer board).
And on the production process of PCBs, in 1947, out of the urgent need for the development of aerospace technology, the U.S. Bureau of Aeronautics and the U.S. Bureau of Standards in that year initiated the first seminar on printed circuit technology, where 26 different manufacturing methods were listed and grouped into the following six categories.
01 Coating method
Mix metal powder and adhesive to make a conductive paint, using the usual printing method to conductive graphics on the substrate (Note: substrate, referring to the PCB board insulation dielectric layer; now used in the buried capacitance buried resistance process, reference to this principle).
02 Moulding method
The use of moulding process, in the plastic insulating substrate on a metal foil, with a conductive pattern engraved on the metal foil of the mould for hot pressing, so that the heat and pressure parts of the metal foil is bonded to the substrate to form a conductive pattern, the rest of the metal foil, is off.
03 Powder sintering method
Using a template with the required graphics, the adhesive is coated on the substrate to form a conductive graphic, and then a layer of metal powder is sprinkled on top, which is then sintered to form a conductive graphic.
04 Spraying method
Cover the insulated substrate with a template and spray the molten metal or conductive paint onto the surface of the substrate, i.e. to form a conductive pattern. (Note: the spray tin process now used, reference to this principle)
05 Vacuum coating method
A stencil is used to cover the insulating substrate and a cathodic sputtering or vacuum evaporation process is used to obtain a metal film pattern under vacuum conditions. (Note: the sputtering process used today takes this principle into account)
06 Chemical deposition method
A chemical reaction is used to deposit the desired metal onto the insulating substrate to form a conductive pattern. (Note: processes such as vapour deposition, which are now used in chip production, refer to this principle)
The above methods, at the time, due to the constraints of the production process, have not been able to achieve large-scale industrial production, but some of them, until now, continue to be borrowed and developed into new processes, new methods.
For now, the modern PCB production process, mainly divided into: additive, subtractive, semi-additive method.
