PCB Technical - Basic knowledge of PCB copper foil thickness

1. Introduction to PCB Copper Foil

Copper foil (copper foil): a kind of cationic electrolytic material, a thin, continuous metal foil deposited on the base layer of the PCB circuit board, which acts as a PCB conductor. It easily adheres to the insulating 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 deposition film on the glass plate.

Copper foil is made of copper and a certain proportion of other metals. Copper foil generally has 90 foil and 88 foil, that is, the copper content is 90% and 88%, and the size is 16*16cm. Copper foil is the most widely used decorative material. Such as: hotels, temples, Buddha statues, golden signs, tile mosaics, handicrafts, etc.

Second, the product characteristics of PCB circuit board copper foil

Copper foil has low surface oxygen characteristics and can be attached to various substrates, such as metals, insulating materials, etc., and has a wide temperature range. Mainly used in electromagnetic shielding and antistatic. The conductive copper foil is placed on the substrate surface and combined with the metal base material, which has excellent conductivity and provides electromagnetic shielding effect. Can be divided into: self-adhesive copper foil, double-conducting copper foil, single-conducting copper foil, etc.

Electronic grade copper foil (purity above 99.7%, thickness 5um-105um) is one of the basic materials of the electronics industry. The rapid development of electronic information industry, the use of electronic grade copper foil is increasing, and the products are widely used in industrial calculators, Communication equipment, QA equipment, lithium-ion batteries, civilian televisions, video recorders, CD players, photocopiers, telephones, air conditioning, automotive electronic components, game consoles, etc. The domestic and foreign markets have an increasing demand for electronic grade copper foil, especially high-performance electronic grade copper foil. Relevant professional organizations predict that by 2015, China's domestic demand for electronic grade copper foil will reach 300,000 tons, and China will become the world's largest manufacturing base for printed circuit boards and copper foils. The market for electronic grade copper foil, especially high-performance foil, is optimistic. .

Third, the global supply status of PCB copper foil

Industrial copper foil can be commonly divided into two categories: rolled copper foil (RA copper foil) and point solution copper foil (ED copper foil). Among them, rolled copper foil has good ductility and other characteristics, which is used in the early soft board process. Copper foil, while electrolytic copper foil has the advantage of lower manufacturing cost than rolled copper foil. Since rolled copper foil is an important raw material for flexible boards, the improvement of the characteristics of rolled copper foil and price changes have a certain impact on the flexible board industry.

Since there are fewer manufacturers of rolled copper foil, and the technology is also in the hands of some manufacturers, customers have a low degree of control over price and supply. Therefore, under the premise of not affecting product performance, electrolytic copper foil is used instead of rolling Copper foil is a feasible solution. However, if the physical properties of the copper foil itself will affect the etching factors in the next few years, the importance of rolled copper foil will rise again in thinner or thinner products, and high-frequency products due to telecommunication considerations.

There are two major obstacles to the production of rolled copper foil, resource obstacles and technical obstacles. The resource barrier means that the production of rolled copper foil requires the support of copper raw materials, and it is very important to occupy resources. On the other hand, technical obstacles discourage more new entrants. In addition to calendering technology, surface treatment or oxidation treatment technology is also the case. Most major global factories have many technology patents and key technology Know How, which increases barriers to entry. If the new entrants post-harvest processing and production, they are restrained by the cost of major manufacturers, and it is not easy to successfully join the market. Therefore, the global rolled copper foil still belongs to the market with strong exclusivity.

Fourth, the development of copper foil

Copper foil in English is electrodepositedcopperfoil, which is an important material for the production of copper clad laminate (CCL) and printed circuit board (PCB) circuit boards. In today's rapid development of the electronic information industry, electrolytic copper foil is called: the "neural network" of electronic product signal and power transmission and communication. Since 2002, the production value of printed circuit boards in China has surpassed the third place in the world. As a PCB substrate material, copper clad laminates have also become the third largest producer in the world. 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 of the world and the development of China's electrolytic copper foil industry, and look forward to the future, experts from China Epoxy Resin Industry Association reviewed its development.