Introduction to Copper Foil

1. Copper foil

Pure copper skin refers to the metal copper layer used for pressing copper-clad laminates or the metal copper layer used for the outer layer of multi-layer boards in printed circuits.

2. Electrodeposited copper foil (ED copper foil)

Copper foil made by electrodeposition. The manufacturing of electrolytic copper foil for printed circuit boards first involves producing the original foil (also known asHair foil "," raw foil ". The manufacturing process is an electrolytic process. Electrolytic equipment generally uses a surface roller made of titanium material as the cathode roller, with high-quality soluble lead based alloy or insoluble titanium based corrosion-resistant coating (DSA) as the anode. Copper sulfate electrolyte is added between the anode and cathode. Under the action of direct current, metal copper ions are adsorbed on the cathode roller to form electrolytic foil. As the cathode roller rotates continuously, the generated foil is continuously adsorbed and peeled off on the roller. Then it is washed, dried, and wrapped into a rolled original foil.

3. Rolled copper foil

Copper foil made by rolling method. Also known as forged copper foil.

4. Double treated copper foil

In addition to treating the rough surface of electrolytic copper foil, the smooth surface is also treated to roughen it. Using this as the copper foil for the inner layer of a multi-layer board does not require roughening (blackening) treatment before laminating the multi-layer board.

5. High temperature elongation electrodeposited copper foil

(abbreviated as)HTE copper foil)

At high temperatures（Copper foil with excellent elongation maintained at 180 ℃. Among them, the elongation at high temperature (180 ℃) of copper foils with thicknesses of 35 μ m and 70 μ m should be maintained at more than 30% of the elongation at room temperature. Also known as HD copper foil.

6. Low profile copper foil (LP)

The microcrystals of the original copper foil are generally very rough, appearing as coarse columnar crystals. The cross-sectional lines of its slices have significant undulations. The crystallization of low profile copper foil is very delicate (below 2 μ m), with equiaxed grains and no columnar crystals, presenting as layered crystals with flat edges. The surface roughness is low. The ultra-low profile electrolytic copper foil has been measured to have an average roughness (Ra) of 0.55 μ m (usually 1.40 μ m for copper foil). The maximum coarsening degree is 5.04 μ m (usually 12.50 μ m for copper foil).

7. Resin coated copper foil (RCC)

Also known as resin coated copper foil domestically. Taiwan refers to it as adhesive backed copper foil. In foreign countries, there are also insulation resin sheets carried on copper foil and adhesive films with copper foil. It is a process of coating one or two layers of specially composed resin adhesive solution (the main component of resin is usually epoxy resin) on the roughened surface of thin electrolytic copper foil (thickness generally ≤ 18 μ m), and then drying it in an oven to remove the solvent, and the resin becomes a semi cured B-stage form. The thickness used for RCC generally does not exceed 18 μ m, with 12 μ m being the most commonly used. The thickness of the resin layer is generally between 40-100 μ m. It plays a role in replacing traditional semi cured sheets and copper foils in the production process of laminated multilayer boards. As an insulating medium and conductor layer, it can be pressed together with the core board using a similar process to traditional multilayer board pressing to produce laminated multilayer boards.

8. Adhesive coated copper foil (ACC)

Also known asGlued copper foil. Copper foil products coated with resin adhesive on the roughened surface of copper foil. The general types of resin adhesives include aldehyde modified phenolic resin, epoxy acrylic resin, nitrile modified phenolic resin, etc. Adhesive coated copper foil and resin coated copper foil (RCC) differ in function, serving only as an adhesive between the copper foil and the insulating substrate. Used for manufacturing paper-based copper-clad laminates and three-layer flexible copper-clad laminates.

9. Lithium ion batteries require copper foil for lithium ion battery

Copper foil used in the manufacture of negative electrode current collectors for lithium-ion batteries. This copper foil serves as both a carrier for negative electrode materials and a collector and transporter for negative electrode electrons in lithium batteries. The copper foil used must have good conductivity. It should ensure good contact with the active substance and be evenly coated on the negative electrode material without peeling off. It should have good contact with activity, good corrosion resistance, smooth surface, and uniform thickness.

10. Ultra thin copper foil

Copper foil for printed circuit boards with a thickness of less than 9 μ m. The commonly used copper foil has an outer layer of 12 μ m or more on multi-layer boards and an inner layer of 18 μ m or more on multi-layer boards. Copper foil below 9 μ m is used on printed circuit boards for manufacturing micro circuits. Due to the difficulty in handling extremely thin copper foil, a carrier is generally used as a support. The types of carriers include copper foil, aluminum foil, organic film, etc.

11. Type of foil

IPC-4562 specifies the types and codes of metal foils based on their manufacturing processes

E - Electrolytic foil

W - Rolled foil

O - Other foils

12. Type of foil: foil grade

Various copper foils were labeled with English letters. As a variety of copper foil models.

Compare the models of various copper foils specified in IPC-4562 (2000) with those named in other standards in the table.

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13. Raw copper foil

Untreated foil produced in electrolytic machines (electrolytic cells) (also known as "untreated foil" in China)Raw foil "," hairy foil ". Raw copper foil is manufactured on this device.

14. Surface treatment

It is an important link in the production of copper foil. It includes roughening layer treatment of copper foil（Rough treatment, barrier treatment (also known as heat-resistant layer treatment), and anti rust treatment (also known as anti-oxidation treatment).

15. Rough layer treatment

To achieve higher adhesive strength between copper foil and substrateThe nodulation treatment performed on rough surfaces

16. Barrier treatment

Also known as heat-resistant layer treatment. In order to improve the heat resistance and high-temperature peel strength of copper foil pressed copper-clad laminates and multilayer boards, other metal layers are electroplated on the roughened layer of copper foil. This prevents direct contact between the bare copper surface and the substrate, avoiding the problem of water vaporization caused by the decomposition of the curing agent melamine in the resin due to high temperature, which may lead to the generation of bubbles and separation of copper foil and substrate.

17. Blackening treatment

Black roughening treatment again. A type of heat-resistant layer treatment. Coat another layer of nickel on the roughened surface. The color of the nickel plating layer is black, hence it is called blackening treatment. This type of copper foil is called nickel plated copper foil.

18. Yellow rounding treatment

A type of heat-resistant layer treatment. Coat another layer of copper zinc alloy (i.e. brass) on the roughened surface. The color of the copper zinc alloy layer is yellow, hence it is called yellowing treatment. This type of copper foil is called brass plated copper foil.

19. Anti rust treatment

Also known as anti-oxidation treatment, passivation treatment, and stability treatment. Copper foil treated with rust prevention is less prone to oxidation, discoloration, and rusting.

20. Rough surface matte side

Electrolytic copper foil (generally referring to the original foil) has a rough and matte surface, which is the side that does not adhere to the cathode roller during production. Compared to the light surface, it is called the hair surface. Also known as processing surface（treated side）。

21. Smooth shiny side

The bright surface of electrolytic copper foil, which is the side attached to the cathode roller during production. Also known as round barrel copper foil（drum side）。 The roughness of the smooth surface is a replica of the roughness of the cathode roller surface. Also known as Untreated Side.

22. Processed side

After roughening, nickel plating or zinc plating, the electrolytic copper foil has improved its adhesion to the substrate on one or both sides.

23. Crop Slitting

The electrolytic copper foil undergoes longitudinal cutting according to the specified size after surface treatment. Trimming is performed on a slicer.

24. Cutting

After surface treatment, the electrolytic copper foil is horizontally cut according to the specified direction and size. The copper foil is cut on a slicer.

25. Cathode cathode

The electrode that undergoes a reduction reaction, that is, the electrode that obtains electrons on the surface of the cathode roller in the electrolysis machine under the condition of passing current.

26. Anode anode

The electrode that undergoes oxidation reaction, that is, the electrode in the anode plate of the electrolysis machine that can receive electrons given by the reactants.

27. Current density

The current intensity passing through a unit area electrode is usually measured byA/dm2 represents. Unless otherwise specified, it generally refers to the negative current density

28. Electrolytic Forming Cell

In the electrolytic copper foil production industry, it is a synonym for "electrolytic machine". It is an important equipment for producing electrolytic copper foil It generally uses a roller with a titanium surface made of specialized titanium material as the cathode roller, and a high-quality lead silver alloy containing 1% silver (or a specially coated titanium plate) as the anode. Copper sulfate electrolyte is added between the anode and cathode, and under the action of direct current, copper metal precipitates on the cathode roller. With the continuous rotation of the cathode roller, copper continuously precipitates on the roller surface, and the precipitated metallic copper is continuously peeled off from the roller, washed and dried, wound into a roll, and formed into the original foil.

  

29. Dimensional stable anode (DSA)

Also known as insoluble anode. A type of anode used in foil making machines. DSA uses titanium material as the support for the anode, and a special coating (such as a mixed ceramic conductive layer of iridium oxide and tantalum oxide) is hot coated on the inner arc surface along the titanium anode to enhance the long-term attack of high current. It exhibits a very stable size compared to lead anodes.

30. Tensile strength

The maximum tensile stress experienced when a specimen fractures under a tensile load applied under specified experimental conditions.

31. Elongation rate

The percentage of the incremental distance between the effective part of the specimen and the initial distance between the markings when the specimen fractures under tensile load.

33. Peel strength

The force required to strip a unit width of wire or metal foil from a copper-clad laminate or printed circuit board perpendicular to the board surface.

34. Base material

An insulating material that can form conductive patterns on it. The substrate material can be rigid or flexible, and can also be uncoated or coated with metal foil.

35. Laminated board

A plate-shaped material formed by laminating two or more layers of semi cured sheets (pre impregnated materials) and bonding them together under heating and pressure.

36. Copper clad laminate (CCL)

A laminated board covered with copper foil on one or both sides, used for manufacturing printed circuit boards, abbreviated as copper-clad board. The general manufacturing process of copper-clad laminates is: gluing（Blending → impregnation → drying → cutting → lay up → lamination → trimming.

37. Single sided copper clad laminate

Copper clad laminates with copper foil on only one side.

38. Double sided copper-clad laminate

A double-sided copper-clad laminate with copper foil.

39. Inner core material

Often refers to the substrate of the inner layer of a multi-layer board. Also known as inner core layer copper-clad laminate.

40. Semi cured sheet (prepreg) prepreg (PP)

After impregnating thermosetting resin with fiber-reinforced material and curing untilB stage sheet materials. Also known as B-stage material and pre impregnated adhesive sheet.

41. Pre impregnated bonding sheet

The "semi cured sheet" of the same 40.

42. Phenolic cellulose paper copper clad laminate

A laminated board made of reinforced fiber paper and phenolic resin insulation substrate and covered with copper foil. commonXPC, XXXPC (non flame retardant) and FR-1, FR-2, FR-3 (flame retardant) models of copper-clad laminates belong to this type of board.

43. Epoxy glass fabric copper clad laminate

A laminated board consisting of an insulating substrate made of glass fiber cloth and epoxy resin, and covered with copper foil. commonG10, G11 (non flame retardant) and FR-4, FR-5 (flame retardant) models of copper-clad laminates belong to this type of board.

44. Composite copper clad laminate

A laminated board containing two or more different types or structures of reinforcing materials and covered with copper foil. commonCEM-1 and CEM-3 models of copper-clad laminates belong to this type of board. CEM-1 is a laminated board made of fiber paper containing epoxy resin as the core, covered with fiberglass cloth containing epoxy resin on the surface, and then covered with copper foil. CEM-3 is a laminated board made of fiberglass non-woven fabric (also known as fiberglass paper) containing epoxy resin as the core, covered with fiberglass cloth containing epoxy resin on the surface, and then covered with copper foil.

45. Thin copper clad laminate

The thickness of copper-clad laminates (including copper foil thickness) is less than0.8mm copper-clad laminate. Mostly used for the inner core material of multi-layer boards.

46. Ultra thin copper clad laminate

The thickness of copper-clad laminates (including copper foil thickness) is onlyCopper clad laminates with a thickness of 1.2-5 mil (0.030-0.127mm). Mostly used in the manufacturing of multi-layer boards.

47. Printed circuit board (PCB)

A printed circuit board is formed on an insulating substrate according to a predetermined design to interconnect electrical circuits from point to point, as well as printed components.