Almost all of the electronics ranging from smartphones to X-Ray scanners have a Printed Circuit Board (PCB). These PCBs are made of Copper-Clad Laminates (CCL), which are a type of base material of PCBs, while the reinforcing material is generally glass fiber or wood pulp paper. These laminates are copper clad on either one or both sides of reinforcing material after being soaked in resin.
Copper-clad laminates are manufactured by pressing layers of filler material impregnated with resin under heat and pressure with copper foil. They are suitable for hot or cold punching and resistant to heat and moisture and exhibit excellent mechanical and electrical properties. A key application for copper-clad laminates is in the manufacture of PCBs used to mechanically support and connect electronic components. This is done by etching pathways, tracks, or signal traces onto a non-conductive substrate.
Based on the side that is functional, PCBs are usually of three types, namely single-sided, double-sided, and multilayer. Single-sided boards have a conductive pattern only on one side of the insulating substrate, while double-sided printed boards have conductive patterns on both sides. Multilayer PCBs, which are in great demand, have more than two sides of conductive patterns that are interlocked with insulating materials and interlinked in accordance with regulation.
Paper has been used as a reinforcement in a number of Printed Circuit Boards. For impregnation, phenolic resin or epoxy resin, cyanate ester, and polyimide are used. This type of CCL is lead-free and highly effective in Printed Wiring Boards (PWB) in consumer appliances such as TV and AV devices. Also, paper CCLs soaked in phenol-formaldehyde are widely used. Paper copper-clad laminates are cheap as they come in laminated tubes formed by hot rolling. They are mechanical heat-resistance and have dielectric properties, due to which they have applications in the insulation of electrical equipment and transformers.
These CCL laminates have glass fiber that is dipped into thermoset epoxy resins and then covered with copper foil that is formed through heat pressing, on either one or both sides. FR-4 (FR denotes flame retardant) is a versatile high-pressure thermoset plastic laminate with a good strength-to-weight ratio. Tg is the glass transition temperature that is related to the durability of the PCB.
They are used in PCBs, power baseboards, PDPs, LCDs, TVs, refrigerators, and washing machines. Laminates with high Tg have better strength, dimensional stability, thermal decomposition, water absorption, and adhesiveness.
This type of laminate is composed of two substrates in which the fabric is glass fiber cloth. The core material used in this type of laminate is bleached kraft paper and is suitable for punching and drilling. With technological advancements, the Comparative Tracking Index (CTI), dimensional precision and stability have improved, due to which use of CEM-1 has increased as compared to CEM-3 and FR-4 products.
Other copper-clad laminates with different dielectrics are polytetrafluoroethylene (PTFE), matte glass and polyester (FR-6), woven glass and epoxy, alumina and polyamide. Due to decreasing size, small dissimilarities such as thickness variations, bubbles in the resin matrix, and uneven distribution of fiberglass are gaining importance. PTFE is a kind of plastic material that offers a minimum resistance and is therefore used in high speed, high-frequency applications.
The dawn of 5G has created a huge demand for copper-clad laminates. Even though 5G technology functions on a wide spectrum of frequencies, it requires a larger number of base stations as compared to 4G technology for the same coverage. Moreover, the PCBs used in 5G also have advanced design capabilities. As per the requirement of properties, the use of PTFE, ceramics, or hydrocarbon/ glass material is preferred over FR-4 glass-reinforced epoxy laminate materials, which are otherwise commonly used in the manufacturing of PCBs.
As per the Ministry of Industry and Information Technology (MIIT) in April 2019, China is the world’s largest producer, consumer, and exporter of consumer electronics. In 2018, China produced 1.8 billion mobile phones, 300 million computers, and 200 million televisions. All these products require PCBs, which in turn require CCLs. In November 2019, China also unveiled its 5G network, which has already been rolled out by other countries such as the U.S., the U.K., and South Korea.
PCB manufacturing in China looks promising even after the U.S.-China trade conflict and the fall in demand for smartphones and cars. According to the Taiwan Printed Circuit Association (TPCA), the output of Taiwanese PCB manufacturers generated USD 9,300 million in the first half of 2019. These manufacturers benefited from certain niche markets for which PCBs made from insulating raw materials were required.
As per the Korea Printed Circuit Association, in 2017, China, Taiwan, Korea, and Japan constituted 81.6% of the world’s PCB production, of which South Korea occupied 13% of the market. Meanwhile, the CCL market of Japan is experiencing a slight downfall, with the Japan Electronics Packaging Circuits Association (JPCA) reporting, in August 2019, that the output value of Japan’s PCB industry dropped by 6.9% to USD 2,060 million in the first half of 2019.
There are a number of prominent global manufacturers of copper-clad laminates such as Kingboard Holdings Ltd., Shengyi Technology (SYTECH), ITEQ Corporation, Panasonic Corp, Isola Group, Nan Ya Plastics Corp, FINELINE Ltd., Doosan Corporation Electro-Materials (South Korea), Grace Electron Corp (Wuxi city and Guangzhou city), Taiwan Elite Material Co., Ltd., Taiwan TAIFLEX Scientific Co., Ltd., UBE Industries, Ltd., Goldenmax International Technology Ltd., and Guagndong Chaohua Technology Co., Ltd.