Electrolytic copper foil And Calendered copper foil Similarities and differences of! Features of calendered copper foil and electrolytic copper foil:

1. Features of electrolytic copper foil:

(1) Electrolytic copper foil has better conductivity

(2) Electrolytic copper foil is loose and easy to break

(3) Electrolytic copper foil is finished by electroplating process.

2. Features of calendered copper foil:

(1) The rolled copper foil has good winding performance,

(2) The unit price of calendered copper foil is more expensive than electrolytic copper foil. The calendered copper foil has compact molecules, good flexibility, and the thinner the better flexibility. Generally, products with bending requirements use calendered copper foil.

(3) Calendered copper foil is produced by coating.

The similarities and differences between electrolytic copper foil and calendered copper foil! Thickness control of calendered copper foil and electrolytic copper foil: usually, the factory has very strict requirements on the thickness of copper foil, which is generally between 0.3mil and 3mil, and there is a special copper foil thickness tester to check its quality. The control of copper foil thickness is mainly based on two reasons

1. A uniform copper foil can have a very uniform resistance temperature coefficient and a low dielectric constant, which can reduce the loss of signal transmission. This is different from the requirement of capacitance, which requires a high dielectric constant, so that it can accommodate a higher capacity in a limited volume. Why is the resistance smaller than the capacitance? In the final analysis, the dielectric constant is high!

2. The temperature rise of thin copper foil is small under the condition of high current, which is very beneficial to heat dissipation and component life. It is also true that the width of copper wire in digital integrated circuits is less than 0.3cm. The well made FPC finished board is very uniform and has a soft gloss (because the surface is brushed with solder resist), which can be seen by the naked eye, but there are few people who can see the good or bad of the copper clad substrate, unless you are an experienced quality inspector in the factory.

Difference between calendered copper foil and electrolytic copper foil:

1. The manufacturing process is different. Electrolytic copper foil is completed by electroplating process, and calendered copper foil is produced by coating.

2. The performance is different. Electrolytic copper foil has better conductivity, and rolled copper foil has better winding performance. Generally, rolled copper foil is used for products with bending requirements. The unit price of rolled copper foil is more expensive than that of electrolytic copper foil.

3. Electrolytic copper foil is loose and easy to break; The calendered copper foil has compact molecules and good flexibility. The thinner the foil, the better the flexibility; Phosphorus containing calendered copper foil has fine molecules and bright post-treatment electroplating appearance, but its flexibility is worse than that of pure calendered copper foil.

4. Electrolytic copper foil is formed by separating copper ions from copper sulfate solution with electric current, and is completed after oxidation resistance and roughening treatment. Calendered copper foil is rolled from copper ingots, and then processed by forging, oxidation resistance, roughening, etc. Relative to electrolytic copper foil, Production of calendered copper foil It is difficult. At present, there are only three companies in the world that can produce in large quantities (according to the relevant report), and the ductility is good (up to 30%, while the SHTE type of electrolytic copper foil is only 15% - 20%). It is mainly used in FPC, laptop, tablet, printer and other places that need shielding.

The similarities and differences between electrolytic copper foil and calendered copper foil! Differences between rolled copper foil and electrolytic copper foil in quality and use:

1. As its name implies, electrolytic copper foil is formed by adsorbing copper ions on the substrate through electrolysis, so its characteristics are: strong conductivity, but relatively weak bending resistance.

2. The calendered copper foil is obtained by extrusion. It is characterized by good bending resistance, but its conductivity is weaker than electrolytic copper foil. It is mainly used for camera in flip phone. From the appearance, the electrolytic copper foil turns red and the calendered copper foil turns yellow.

Difference between calendered copper foil and electrolytic copper foil manufacturing method:

1. Calendering copper foil is to stick high-purity (>99.98%) copper onto FPC by rolling -- because FPC and copper foil have excellent adhesion, the adhesion strength and working temperature of copper foil are high, and it can be dip welded in 260 ℃ molten tin without foaming. This process is quite like rolling dumpling skin, the thinnest can be less than 1mil (industrial unit: mil, that is one thousandth of an inch, equivalent to 0.0254mm). If the skin of the dumpling is so thin, the filling will leak in the next pot!

2. Electrolytic copper foil has been learned in junior high school chemistry. CuSO4 electrolyte can continuously produce layers of "copper foil", which is easy to control the thickness. The longer the time, the thicker the copper foil!

The difference between the microstructure of calendered copper foil and electrolytic copper foil: due to the different processing technology, the section of the material is observed under a 1000x microscope, and the atomic structure of the calendered copper is irregular layered strong crystal. For the recrystallization after heat treatment, it is not easy to form cracks, and the copper foil material has good bending performance; The electrolytic copper foil material presents columnar crystal structure in the thickness direction, which is prone to crack and fracture when bending; Similarly, when observing the cross section of high elongation electrolytic copper foil material after heat treatment and other special processing, although columnar crystals are still dominant, layered crystals are formed in the copper layer and are not easy to break when bending.