For RF and microwave design teams, Rogers RO4350B has become one of the most widely used high-frequency substrates on the market.
Boards built with this material are known as Rogers RO4350B PCB, and they solve a real industry pain point: reliable high-frequency performance without the high cost of PTFE-based materials.
Rogers RO4350B PCB provides the low loss and stable dielectric properties RF engineers need for consistent impedance-controlled designs, including filters, couplers and signal distribution networks. This combination makes it particularly well suited for broadband RF and microwave systems.
Specifying RO4350B is mostly a paperwork exercise on the buying side. Three numbers matter when you compare quotes: Dk 3.48 ±0.05, Df 0.0037 at 10 GHz, and a Z-axis CTE of 32 ppm/°C. Thickness availability, panel size, copper foil type and lead time differ between distributors, so ask for the current datasheet revision and a stack-up drawing with your quote, not after the order.
That is why an RO4350B quote is worth reading line by line. Two boards with the same grade name can differ in core thickness, foil type and panel utilization, and those are the lines that move the price.
What to Ask Before You Quote
A quote on RO4350B only compares once the same paperwork sits behind every bid. Ask for the items below in writing, and the numbers start to mean something.
- The datasheet revision the laminate is cut from, not just the grade name
- A stack-up drawing with core thickness, prepreg type and finished copper weight for every layer
- Copper foil type, since HVLP and standard foil differ in insertion loss and in price
- Which thicknesses sit in stock and which need a mill order
- Panel size and the panelization proposed, because it sets material utilization
- Lead time counted from material arrival, not from the order date
- Minimum order quantity and the price breaks above it
- Whether an impedance test coupon report ships with the boards
Drilling Performance and Tool Life
RO4350B drills cleanly with standard epoxy/glass-compatible bits. Hole-wall roughness stays between 8 and 25 microns even after extended tool use, and tools commonly pass 2,000 hits while holding acceptable quality. Drilling parameters, tool-life data and lamination notes are collected in our RO4350 fabrication guide.
Two process steps decide whether those numbers hold in production. Aluminum entry foil with a phenolic backup board stops the exit side from chipping, and the panel is deburred before plating. RO4350B is a hydrocarbon resin rather than an epoxy, so the desmear step ahead of plated-through-hole metallization runs on permanganate with a narrower window than FR-4 allows. Push it too hard and the resin under the copper lifts.
Processing and Cost Advantages
Rogers RO4350B laminates offer tight Dk control and low loss while using nearly the same fabrication flow as standard FR-4.
Multilayer builds bond the cores with RO4450F prepreg, pressed on a cycle close to FR-4 but with a slower ramp so the resin does not flow out at the panel edge. In a hybrid stack that mixes RO4350B cores with FR-4, keep the high-frequency layers symmetric about the center line and check the Z-axis expansion of the whole stack, not only of the Rogers core.
They cost significantly less than conventional microwave laminates and do not require special through-hole treatments or handling associated with PTFE materials.
The material carries a UL 94 V-0 flammability rating, making it suitable for active devices and high-power RF circuits where safety and reliability are required.
Key Specifications
- Dielectric Constant (Dk): 3.48 ± 0.05
- Dissipation Factor (Df): 0.0037 at 10 GHz
- Z-axis Thermal Expansion: 32 ppm/°C
The full sheet, including Dk and Df across frequency, sits in our RO4350B datasheet.
Real-World Benefits
- Compatible with standard FR-4 processes for lower fabrication cost
- Lower cost than traditional high-frequency laminates
- Excellent dimensional stability across temperature and frequency
Before you commit a stack-up, our RO4350B laminate performance comparison sets it against RO4003C and RO4450F.
OPCBA operates production lines optimized for Rogers RO4350B PCB manufacturing. If you’re working on an RF, microwave or broadband design, we can support your prototype and volume production needs.
Contact us today to discuss your project.
