CCL

Copper Clad Laminate (CCL) in rigid boards, also called PCB laminate, is a type of substrate material of printed circuit boards with a thin layer of copper laminated on either one side or both sides, and we call it as single-sided CCL or double-sided CCL. In rigid PCB production, manufacturers use rigid CCLs with substrate material, like resin epoxy (FR4), metal core (alu or copper), PTFE and Ceramic, to fabricate single-, double- and multi-layer circuit boards.

 

 

Resin Epoxy FR-4 CCL

 

FR-4 (or FR4) copper clad laminate (CCL) is a rigid PCB substrate material with copper clad on either one side or both sides of FR4 base, which is a composite material composed of woven fiberglass cloth with an epoxy resin binder that is flame resistant. FR stands for flame retardant, and does not denote that the material complies with the standard UL 94V-0 unless testing is performed to UL 94, Vertical Flame testing in Section 8 at a compliant lab. The designation FR-4 was created by NEMA (National Electrical Manufacturers Association) in 1968.

 

Properties of FR-4 CCL:

 

• Low Glass Transition Temperature (Tg) (Tg130 ^oC – Tg140 ^oC)
• Mid Glass Transition Temperature (Tg) (Tg150 ^oC)
• High Glass Transition Temperature (Tg) (Tg170^oC)
• High Decomposition Temperature (Td) (Td>345^oC)
• Dielectric Constant (Dk or Er) (@1GHz): 3.66-4.5
• Dissipation Factor (Df) (@1GHz): 0.016
• High UL Rated Flammability: 94V-0
• Low Coefficient of Thermal Expansion (CTE) (2.5%-3.8%)
• High Comparative Tracking Index (CTI): (CTI >=600V)
• Halogen-free
• Compatible with standard and lead-free assembly
• FR4 CCL thickness available from 0.2mm to 3.2mm
• Copper thickness available form 1/3oz to 3oz

 

Aluminum Core CCL

 

Aluminum (Aluminium or Alu) core or Aluminum base copper clad laminate (CCL) is made of aluminum plate, dielectric bonding layer and copper foil by high temperature and hot pressing. The metal layers are with high thermal conductivity, while the overall conductivity of the Aluminum core laminate is decided by the dielectric bonding layer. With high thermal conductivity, the dielectric may be filled with ceramic.

Most aluminum PCB boards are built with single-sided CCL, while double-sided CCL for double-sided Aluminum PCB and multilayer hybrid Aluminum PCB manufacturing are possible at MADPCB.

 

Properties of Aluminum Core CCL:

 

• Thermal Conductivity: 1.0W/m·K, 1.5W/m·K, 2.0W/m·K, 3.0W/m·K, 4.2W/m·K, 5.0W/m·K, 7.0W/m·K
• Aluminum (Al) Alloy Style: 1060 (138 W/m·K) and 5052 (220 W/m·K)
• Copper (Cu) Style: C1100 (386 W/m·K)
• Copper thickness available from 0.5oz to 2oz
• Glass Transition Temperature (Tg): Tg100^oC, Tg120^oC, Tg130^oC
• Dielectric Constant (Dk or Er) (@1MHz): 4.8
• Halogen-free
• Compatible with standard and lead-free assembly
• High UL Rated Flammability: 94V-0
• Aluminum Core CCL thickness available from 0.8mm to 2.0mm

 

Copper Core CCL

 

Similar to Aluminum Core CCL, Copper Core CCL is made of copper plate, dielectric bonding layer and copper foil. The thermal conductivity is mainly decided by the bonding dielectric layer and whether your board has thermal dissipation design.

Copper Core PCB, also referred to copper substrate PCB, copper based PCB or copper clad PCB, which has 3 main design types:

• Common copper core PCB: (with circuitry on copper layer without PTH)
• Chip on Board (COB) copper PCB
• Direct thermal path copper-based PCB (no insulator under the thermal path pad)

 

Properties of Copper Core CCL:

 

• Thermal Conductivity: 3.0W/m·K, 5.0W/m·K, 7.0W/m·K
• Copper (Cu) Style: C1100 (386 W/m·K)
• Copper thickness available from 0.5oz to 2oz
• Glass Transition Temperature (Tg): Tg100^oC, Tg120^oC, Tg130^oC
• Dielectric Constant (Dk or Er) (@1MHz): 4.8
• Halogen-free
• Compatible with standard and lead-free assembly
• High UL Rated Flammability: 94V-0
• Copper Core CCL thickness available from 0.8mm to 2.0mm

 

Radio Frequency (RF) /Microwave PCB CCL

 

When your PCB boards designed at microwave frequencies, the key characteristics that define CCL and prepreg (PP) performance for microwave/RF printed circuit boards include dielectric constant (Dk), dissipation factor (Df), coefficient of thermal expansion (CTE), thermal coefficient of dielectric constant (TCDR), and thermal conductivity.

The high-frequency material perhaps most familiar to designers and manufacturers is PTFE (Polytetrafluoroethylene), which is a synthetic thermoplastic fluoropolymer that has excellent dielectric properties at microwave frequencies. Below is a brief outline of the major material suppliers that we have experience with as every material is processed a bit differently and it is critical to know exactly how the materials will respond to every process.

 

There are 4 copper clad laminate companies manufacture high-frequency materials:

 

• Isola High Performance PCB laminates: since their founding in 1912, Isola has been the industry leader in developing and manufacturing copper-clad laminate products used to fabricate advanced multilayer printed circuit boards (PCBs). They have an optimal balance between cost and performance when selecting base materials. Key factors microwave and millimeter wave designers must consider when choosing a high-speed RF or microwave laminate include dielectric thickness, dielectric constant and dissipation factor, and maintaining tight tolerance within a batch as well as batch-to-batch. RF high-frequency PCB designs require extremely precise controls on dielectric constant, trace widths, and dielectric thickness.

 

• Rogers Advance Laminates for RF/Microwave Designs: As one of the oldest public companies in USA, Rogers has a rich legacy of innovative and collaborative problem-solving techniques with our customers. In 1949, Rogers introduced the first RT/duroid® material for electronic applications and today the RT/duroid® family of high frequency PTFE laminates is the leader in the industry for high speed RF/microwave PCB designs. Most PTFE PCB laminates require special equipment and processes to manufacture the highest reliability PCBs along with significant expertise in the material properties as many of the materials behave differently during PCB processing. The best-known brand name of PTFE-based formulas is Teflon, which is used in non-stick cooking pans which means that this material can be difficult to work with if you don’t have the proper experience.

 

• Taconic Advanced PCB Dielectric Laminates: Taconic has been a world leader in the PTFE products sine 1961. Today they provide PTFE and silicon coated fabrics, tapes, and laminates for a range of high-performance application. Thermally stable, low Dk, low Z axis CTE PTFE laminates are the focus for the Taconic materials used in the manufacturing of RF/microwave PCB boards. Many of the Taconic products are designed with ultra-low fiberglass content to achieve world class insertion loss properties and a homogeneous dielectric constant throughout the laminate. The uniform dispersion of ceramic throughout the laminate yields extremely low X and Y coefficients of thermal expansions. Taconic has materials for every application and a partial list of their offering.

 

• Panasonic MEGTRON 6: MEGTRON 6 from Panasonic is an advanced printed circuit board (PCB) laminate material designed for high-speed applications such as network equipment, mainframes, IC testers, and high frequency measuring instruments. MEGTRON 6 material is best-known for low dielectric constant and dielectric dissipation factors, as well as low transmission loss and high heat resistance.