Flexible copper clad laminate (FCCL) is the raw material of flexible printed circuit board (FPC).
FCCL is thin, light and flexible, it also has excellent electrical, thermal and heat resistance properties. Because of its low dielectric constant (DK), the electrical signal can be transmitted quickly. Good thermal performance can make the components easy to cool down. Higher glass transition temperature (TG) can make the module operate well at higher temperature. Since most of the products of FCCL are provided to users in the form of continuous coils, the use of FCCL to produce printed circuit boards is conducive to the automatic continuous production of FPC and the continuous surface installation of components on FPC.
Flexible copper foil substrate (FCCL) can be divided into two categories: traditional three-layer substrate with adhesive (3L-FCCL) and new two-layer substrate without adhesive (2L-FCCL). It is composed of flexible insulating base film and metal foil. The flexible copper clad laminate, which is composed of copper foil, film and adhesive, is called three-layer flexible copper clad laminate (3L-FCCL). The flexible copper clad laminate without adhesive is called two-layer flexible copper clad laminate (2L-FCCL). Because the manufacturing methods of these two kinds of soft copper foil substrates are different, the material properties of these two kinds of substrates are also different. In terms of application, the application products of the two types of FCCL are different. 3l-fccl is applied to bulk soft board products, while 2L-FCCL is applied to higher-level soft board manufacturing, such as soft and hard board, COF, etc.
The composition of flexible copper clad laminate mainly includes three types of materials:
Insulating base film materials: the insulating base film materials for flexible copper clad laminate include liquid crystal polymer (LCP) film, polyester (PET) film, polyimide (PI) film, polyester imide (PEI) film, fluorocarbon film, imine fiber paper, polybutene phthalate film, etc. Among them, the most widely used are polyester film (PET film) and polyimide film (PI film) and liquid crystal polymer (LCP) film. New high-performance polymer materials are developing to replace PI (polyimide) film, among which the most influential are liquid crystal polymer (LCP) and polyether ether ketone (PEEK). From the basic properties of the film, these two kinds of polymer materials can effectively make up for the defects of PI (polyimide) film, mainly including low moisture absorption, low coefficient of thermal expansion, low dielectric constant and high dimensional stability.
Metal conductor foil is the conductor material for flexible copper clad laminate, including copper foil (ordinary electrolytic copper foil, high ductility electrolytic copper foil, calendered copper foil), aluminum foil and copper beryllium alloy foil. Copper foil rae mostly used, including electrolytic copper foil (ED) and rolled copper foil (RA).
Adhesive is an important part of three-layer flexible copper clad laminate, which directly affects the product performance and quality of flexible copper clad laminate. The main adhesives used for flexible copper clad laminate are polyester adhesives, acrylic adhesives, epoxy or modified epoxy adhesives, polyimide adhesives, phenolic butyral adhesives, etc. In the three-layer flexible copper clad laminate industry, adhesives are mainly divided into acrylic adhesives and epoxy adhesives.
It includes: PI film, PET film, polyester film, polyimide film, acrylic film, epoxy film, single-sided copper foil substrate, double-sided copper foil substrate, electrolytic copper foil substrate, calendered copper foil substrate, liquid crystal polymer (LCP) film, PI film substrate, PET film substrate, PVC film substrate, pen film substrate, polyimide copper foil substrate Foil base material, polyester copper foil base material, PVC copper foil base material, PTFE copper foil base material, adhesive free copper foil base material, double-sided adhesive free copper foil base material, single-sided adhesive free copper foil base material, acrylic pure film, epoxy resin pure film.
film thickness：25μm, 30μm, 35μm, 36μm, 38μm, 40μm, 42μm, 50μm, 60μm, 75μm, 80μm, 100μm, 115μm, 120μm, 125μm, 160μm, 320μm;
film width：120mm, 130 mm, 150 mm, 250 mm, 260 mm, 270 mm, 280 mm, 300 mm, 304 mm, 305 mm, 310 mm, 330 mm, 450 mm,500 mm, 510 mm, 550 mm, 600 mm, 610 mm, 630 mm, 750 mm, 800 mm, 810 mm, 1220 m, 1300 mm;
film length：250mm, 300 mm, 305 mm, 420 mm, 450 mm, 500 mm, 600 mm, 610 mm, 630 mm, 750 mm, 800 mm, 810 mm, 1220 mm, 1300 mm, 25M, 27.4M, 50M, 100M, 600M, 1000M.
The main suppliers of copper foil base materials are: Nippon Steel, Nippon mektron, Arisawa, Toray, Mitsui chemical, Nitto denko, 3M, DuPont, Taihong, changjieshi, Lvsheng, Xinyang, etc.
日本的生产全球约二分之一的FCCL原料，而大厂数目亦是全球最具规模的国家，生产的FCCL涵盖了3L-FCCL与2L FCCL，各厂的生产情形不同，但是日本厂商因为重视研发且于制程技术上注重品质管制，所以一般而言，全球的FPC厂商对于日本的FCCL接受度普遍较高。美国生产FCCL的产量并无明显成长的趋势，但是美国有能力供应特殊用途的FCCL材料，特用材料的产品型态以片状（sheet）居多，Roll材料，其部份并以宽幅的型式呈现。美国厂商生产2L的比例较高，所以美国摆脱大量生产的方式，改生产特殊利基型的产品。日本、美国朝 laminate 2L FCCL研发，尤其在two metal 制程和使用TPI原料上，美国2L FCCL 的生产制程中，casting 制程占80%；sputtering占15%, laminate则小于5%。未来在2L FCCL制程稳定且价格降至市场可接受的范围时，将有部份的3L FCCL被2L FCCL被取代，直到一个稳定平衡的的应用市场，3L FCCL与2L FCCL各有其应用市场。
以全球供应的观点来看，全球最大的供应商为日本的Nippon Steel，约占有全球81%的市场，以供应国而言属於日本和美国厂居多，三层有胶系软性铜箔基板材主要的供应商有： Nippon Mektron、Arisawa、Toray等。二层无胶系软性铜箔基板材则以Nippon Steel、Mitsui Chemical、Nitto Denko、3M等为主。