RO4350B And FR4 Combination For High Reliability PCB Application

RO4350B and FR4: The perfect combination for high-reliability PCB application

Hello, Today we want to share a 6-layer hybrid PCB, which has been supplied with the highest quality materials and construction details to ensure optimal performance. The PCB material used consists of Rogers RO4350B and ITEQ IT180A FR-4, and has undergone a lead-free process to enable it to operate in temperatures ranging from -40℃ to +85℃.

The board, including tooling strips, measures 98 x 95 mm and has a minimum trace/space of 6/6 mils and a minimum hole size of 10 mils. No blind or buried vias are present, and the board's construction includes base copper of 35um, prepreg, and IT180A FR-4 layers, with a finished board thickness of 1.6 mm and finished Cu weight of 1 oz (1.4 mils) all layers.

The surface finish of the board has been achieved using ENIG (Electroless Nickle and Immersion Gold), with the top and bottom silkscreen in white. The top solder mask is in matt black, as is the bottom solder mask. There is no silkscreen on the solder pads, and the board's quality is ensured through the use of a 100% electrical test.

This PCB has been designed to match an impedance of 50ohm, with a +/- 10% tolerance, and the top layer has 18mil/10mil track and spacing. Impedance matching is achieved using reference layer 2.

In this PCB, we supply a panelized solder paste stencil for the top side of the board. The PCB statistics are impressive, with 107 components, 235 total pads, 71 thru-hole pads, 79 top SMT pads, 85 bottom SMT pads, 263 vias, and 81 nets.

If you have any technical questions or inquiries about our PCB, please contact Ivy at sales10@bichengpcb.com. Our high-quality PCB can be purchased today, ensuring maximum performance.

The benefits of using RO4350B and FR4 for high-reliability PCB applications

-Best practice for designing with RO4350B and FR4 material

High-performance printed circuit board (PCB) design involves selecting the ideal materials for the job, taking into account their individual properties and how they can impact the PCB's performance. Two commonly used materials in PCB design are RO4350B and FR4, each with unique characteristics that can affect the PCB's functionality. In this comprehensive guide, we'll explore the differences between these materials and how they can be used in high-performance PCB design.

Dielectric Constant and Dissipation Factor

The dielectric constant and dissipation factor are crucial factors to consider when designing high-frequency applications. RO4350B boasts a typical dielectric constant of 3.48±0.05 and a dissipation factor of 0.0037 at 10 GHz/23℃. Comparatively, FR4 has a dielectric constant of around 4.4 and a dissipation factor of around 0.02. RO4350B's low dielectric constant and dissipation factor make it an ideal choice for high-frequency applications.

Thermal Coefficient of ε and Thermal Conductivity

Another important factor to consider is the thermal coefficient of ε and thermal conductivity. At 80℃, RO4350B has a thermal coefficient of ε of +50 ppm/℃ and a thermal conductivity of 0.69 W/M/oK. FR4, on the other hand, has a thermal coefficient of ε of around 150 ppm/℃ and a thermal conductivity of around 0.3 W/M/oK. RO4350B's low thermal coefficient of ε and high thermal conductivity make it an ideal choice for thermal management in PCBs.

Electrical Strength and Surface Resistivity

Electrical strength and surface resistivity are also important factors to consider in PCB design. RO4350B has an electrical strength of 31.2 (780) Kv/mm (v/mil) at 0.51mm (0.020"), while FR4 has an electrical strength of around 20 Kv/mm (v/mil). RO4350B also has a surface resistivity of 5.7 x 109 MΩ, which is much higher than FR4's surface resistivity of around 1 x 106 MΩ. These properties make RO4350B a better choice for high-voltage applications and for preventing electrical interference between components.

Tensile and Flexural Strength

When it comes to mechanical strength, RO4350B also has an advantage over FR4. RO4350B has a tensile modulus of 16,767 MPa (2,432 ksi) in the X direction and 14,153 MPa (2,053 ksi) in the Y direction, while FR4 has a tensile modulus of around 3,000 MPa (435 ksi). RO4350B also has a higher flexural strength of 255 MPa (37 kpsi) compared to FR4's flexural strength of around 240 MPa (35 kpsi).

Dimensional Stability and Coefficient of Thermal Expansion

Dimensional stability and coefficient of thermal expansion are important factors to consider in PCB design, particularly in high-temperature environments. RO4350B has a dimensional stability of less than 0.5 mm/m (mil/inch) after etch+E2/150℃ and a coefficient of thermal expansion of 10 ppm/℃ in the X direction, 12 ppm/℃ in the Y direction, and 32 ppm/℃ in the Z direction. FR4 has a similar dimensional stability but a higher coefficient of thermal expansion of around 17 ppm/℃.

Moisture Absorption and Copper Peel Strength

Moisture absorption and copper peel strength are other important factors to consider in PCB design. RO4350B has a moisture absorption of 0.06% after 48 hours immersion at 50℃, while FR4 has a moisture absorption of around 0.15%. RO4350B also has a higher copper peel strength of 0.88 N/mm (5.0 pli) after solder float with 1 oz. EDC foil, compared to FR4's copper peel strength of around 0.5 N/mm (3.0 pli).

Flammability and Lead-free Process Compatibility

Flammability and lead-free process compatibility are important factors toconsider in PCB design, particularly in terms of safety and environmental impact. RO4350B has a UL 94 V-0 flammability rating, indicating excellent flame resistance. It is also compatible with lead-free processes, making it an environmentally friendly choice. FR4, on the other hand, has a lower flammability rating of UL 94 V-1, indicating less flame resistance.

In conclusion, both RO4350B and FR4 have their unique properties and advantages in high-performance PCB design. RO4350B is best suited for high-frequency applications, thermal management, high-voltage applications, and components requiring mechanical strength. FR4, on the other hand, is a more affordable option and is suitable for less demanding applications. When selecting the ideal material for your PCB, it is essential to consider your specific application requirements and select the material that best meets those needs.