PCB circuit board copper foil basic knowledge

Introduction to copper foil

Copper foil: A negative electrolytic material, a thin, continuous metal foil deposited on the substrate of the circuit board, which acts as the conductor of the PCB. It is easily bonded to the insulation layer, accepts the printed protective layer, and forms a circuit pattern after corrosion. Copper mirror test(copper mirror test) : A flux corrosion test using a vacuum precipitated film on a glass plate.

Copper foil is made of copper plus a certain proportion of other metals, copper foil generally has 90 foil and 88 foil two, that is, the copper content is 90% and 88%, the size is 16*16cm. Copper foil is the most widely used decorative material. Such as: hotels, temples, Buddhist statues, gold signboards, tile mosaics, handicrafts and so on.

Second, product characteristics

Copper foil has low surface oxygen characteristics, can be attached to a variety of different substrates, such as metal, insulation materials, etc., with a wide temperature range. Mainly used in electromagnetic shielding and antistatic, the conductive copper foil is placed on the substrate surface, combined with the metal substrate, has excellent conductivity, and provides the effect of electromagnetic shielding. Can be divided into: self-adhesive copper foil, double guide copper foil, single guide copper foil and so on.

Electronic grade copper foil (purity above 99.7%, thickness 5um-105um) is one of the basic materials of the electronic industry, the rapid development of the electronic information industry, the use of electronic grade copper foil is increasing, products are widely used in industrial calculators, communication equipment, QA equipment, lithium ion batteries, Civilian TV, video recorder, CD player, photocopier, telephone, heating and cooling air conditioning, automotive electronic parts, game consoles, etc. The demand for electronic grade copper foil, especially high performance electronic grade copper foil, is increasing at home and abroad. Relevant professional institutions predict that by 2015, China's domestic demand for electronic grade copper foil will reach 300,000 tons, China will become the world's largest manufacturing base of printed circuit boards and copper foil, electronic grade copper foil, especially high-performance foil market is optimistic.

Third, the global supply of copper foil

Industrial copper foil can be commonly divided into two categories: calendered copper foil (RA copper foil) and point decomposition copper foil (ED copper foil), of which calendered copper foil has better ductility and other characteristics, and is the copper foil used in the early flexible plate process, while electrolytic copper foil has the advantage of lower manufacturing cost than calendered copper foil. As calendered copper foil is an important raw material of soft plate, the characteristic improvement and price change of calendered copper foil have a certain impact on the soft plate industry.

Because there are fewer manufacturers of rolled copper foil, and the technology is also in the hands of some manufacturers, so the customer's grasp of the price and supply is low, so under the premise of not affecting the performance of the product, using electrolytic copper foil instead of rolled copper foil is a feasible solution. However, if the next few years due to the physical characteristics of the copper foil structure itself will affect the etching factors, in the fine line or thin products, in addition to high-frequency products due to telecommunications considerations, the importance of rolled copper foil will increase again.

There are two major obstacles to the production of rolled copper foil, the obstacle of resources and the obstacle of technology. The resource barrier refers to the need for copper raw material support for the production of rolled copper foil, and the possession of resources is very important. On the other hand, technical barriers deter more new entrants, in addition to calendering technology, surface treatment or oxidation treatment technology is also. Most of the global manufacturers have many technical patents and key technology Know How to increase the barriers to entry. If the new additions are processed after the production, and are subject to the cost of the large factory 拑 system, it is not easy to successfully join the market, so the global rolled copper foil still belongs to the strong monopoly market.

Four, the development of copper foil

Copper foil for electrodeposited copperfoil in English, is copper clad (CCL) and printed circuit board (PCB) manufacturing of important material. In the rapid development of today's electronic information industry, electrolytic copper foil is known as the "neural network" of electronic product signal and power transmission and communication. Since 2002, the production value of China's printed circuit board has entered the world's third place, and as the substrate material of PCB, copper-clad plate has also become the world's third largest producer. As a result, China's electrolytic copper foil industry has developed by leaps and bounds in recent years. In order to understand and understand the past and present development of the world and China's electrolytic copper foil industry, and look forward to the future, according to experts of China Epoxy Resin Industry Association, the development of it is reviewed.