Basic knowledge of copper foil tape

There are two types of copper foil: bare copper and adhesive-backed copper foil with a layer of mylar tape covering the surface of the adhesive-backed copper foil, and vice versa for bare copper.

1. White bare copper foil, mainly copper and nickel is the main raw material.
2. Purple bare copper foil, mainly made of pure copper, the purity of copper can reach more than 99.9%.
3. Yellow bare copper foil, mainly made of copper and zinc, with different ratios of the two raw materials and different properties and uses.
4. Green bare copper foil, mainly copper and tin is the main raw material.

Appearance quality

• Both sides of copper foil shall not have scratches, pressure pits, wrinkles, dust, oil, corrosives, fingerprints, pinholes and penetration points, and other defects affecting the life, serviceability, or appearance of copper foil.

Unit area quality

• In the manufacture of printed wiring boards, generally speaking, under the same conditions of the manufacturing process, the thinner the thickness of copper foil, the higher the accuracy of the line produced. However, as the thickness of copper foil decreases, the quality of copper foil becomes more difficult to control, and the production process of copper foil becomes more demanding. Generally, double-sided printed circuit boards and multilayer boards use 0.035mm copper foil for the outer circuit and 0.018mm copper foil for the inner circuit of multilayer boards. 0.070mm copper foil is mostly used for the power layer circuit of multilayer boards. As the level of electronic technology continues to improve, the accuracy of the printed circuit requirements is increasingly high, now a large number of 0.012mm copper foil has been used, and 0.009mm, and 0.005mm carrier copper foil is also in use.

Peel strength

• In the manufacture of printed wiring boards, the important characteristics of copper foil are clearly required in the copper foil standard. However, the peel strength, whether IEC, IPC, JIS, or GB/T5230, does not have clear requirements for this, and only stipulates that the peel strength should be in accordance with the procurement documents or agreed by the supply and demand sides. For PCB with electrolytic copper foil, the most important of all properties is the peel strength. The copper foil is pressed together on the outer surface of the laminate, and if the peel strength is poor, the copper foil lines formed by etching may be more easily disconnected from the surface of the insulating substrate material. In order to achieve a stronger bond between the copper foil and the substrate, the rough surface of the raw foil (bonding surface with the substrate) needs to be roughened to form a solid lumpy, and dendritic crystalline surface and a rough surface with a high degree of spread to achieve a high specific surface area, strengthen the adhesion and embedding of the resin (resin on the substrate or copper foil adhesive resin) penetration, and also increase the chemical affinity of copper and resin.
  In general, for the outer layer of printed wiring boards with electrolytic copper foil, the peel strength needs to be greater than 1.34kg/cm.

Oxidation resistance

• Since the 1990s, due to the development of printed circuit technology, the formation of printed circuit boards with copper-clad laminates must be able to withstand higher temperatures and longer heat treatment than in the past. The surface of copper foil, especially for the welding surface (copper foil glossy surface) of the resistance to thermal oxidation discoloration performance has put forward higher requirements.

• Copper foil tape is an excellent electrical conductor, ideal for electrical and electronic applications.
• Copper foil tape is easy to use and can be cut with scissors to the desired size and shape. It's perfect for all kinds of DIY can withstand high temperatures, and is resistant to moisture and chemicals.