Microwave Tech - Rogers RO4835 laminate dielectric constant data sheet, high frequency circuit board material

Rogers RO4835™ laminate dielectric constant data sheet, high frequency circuit board material

RO4835™ laminates are suitable for applications that require higher stability at high temperatures and more oxidation resistance than standard RF thermoset materials. As part of the RO4000® series of materials containing hydrocarbon resins and ceramic fillers, RO4835 laminates can provide excellent high-frequency performance and low circuit processing costs.

As time goes by and temperature changes, oxidation will affect all thermoset sheets, including FR-4 sheets. In the long run, oxidation will lead to a slight increase in the dielectric constant and loss factor of the circuit board. The rate of change and the effect on circuit performance depend on the specific design and operating temperature. For applications that require higher stability when the temperature rises, Rogers has successfully developed the Ro4835TM circuit board, which can be more stable in high temperature environments.

Compared with other radio frequency thermosetting materials, its oxidation resistance is greatly improved. In addition, the electrical properties of Ro4835 The performance and mechanical properties are almost the same as that of Ro4350BTM, which has been successfully used by customers for many years. As a member of the Ro4000 series of hydrocarbon material family, Ro4835 provides excellent high frequency performance and low circuit production costs.

When the operating frequency of the circuit is above 500MHz, the range of plates that the design engineer can choose will be greatly reduced. Ro4000 series materials have the attributes required by RF and microwave circuit design engineers, allowing them to design circuits easily, such as network matching and impedance control of transmission lines. The Ro4000 series board has low dielectric loss, so it can be used in higher operating frequencies that traditional circuit boards cannot apply. The coefficient of thermal expansion (CTE) of Ro4000 series boards is close to that of copper, which brings many benefits to circuit designers. It can provide better dimensional stability. This characteristic is more conducive to the structure of the mixed-voltage circuit board. Even in severe thermal shock applications, the low Z-axis CTE of the Ro4000 series plates ensures the quality of the metallized vias. The Tg of RO4000 series board is greater than 280°C (536°F), so its thermal expansion characteristics remain stable throughout the circuit processing temperature range.

RO4835T™ laminate is a ceramic-filled, low-loss thermosetting material using special open fiber glass cloth. There are three thicknesses of 2.5 mil, 3 mil, and 4 mil. Its dielectric constant (Dk) is 3.3. It is specially designed for the use of the inner layer of the multilayer board structure. It is a good supplement to the need for thinner RO4835™ materials.

In recent years, the global mobile network has continued to evolve, from GSM, to the emergence of WCDMA and LTE, which has enabled users' data flow to increase at an astonishing speed. Among them, Rogers' high-frequency circuit board materials also play a very key role in this market. Equipment such as antennas, power amplifiers, and microwave backhaul are necessary devices for establishing these mobile networks, and they all require low-loss materials with stable dielectric constants. High-frequency circuit materials are the key supporting technology for the development of mobile networks. The next-generation 5G mobile network technology using millimeter wave frequency bands will generally adopt multilayer board structure design. The Ro4835T laminate has a thinner media thickness and a variety of thickness options, and is fully compatible with Ro4450F™ prepreg, the new Ro4450T™ thin prepreg and CU4000™/CU4000LoPro® copper foil products. When used together with Ro4835 laminates and Ro4000® bonding materials, the combination of these materials allows designers to more flexibly meet the requirements of high-multilayer board (MLB) design.

Ro4835T laminate has the same oxidation resistance as Ro4835 laminate, with ultra-low loss, dielectric constant tolerance control, and strict thickness control, which can provide excellent and stable wireless performance for the circuit. In addition, its high-performance material properties make it cost-effective and stable.

In order to meet the requirements of UL 94V-0, Ro4835 laminates use flame retardant technology that meets RoHS requirements. These materials meet the requirements of IPC-4103.

main advantage
1-Compared with traditional thermosetting materials, its oxidation resistance is increased by 10 times
2- Excellent electrical performance enables applications with higher operating frequencies
3- No bubbles or stratification
4- Reliable plated through holes
5- Maintain stability in the entire circuit processing temperature range

Typical application
1-Automotive radars and sensors
2-point-to-point microwave transmission
3- power amplifier
4-phased array radar
5-RF components

What is the difference between RO4835 and RO4350?
The dielectric constant and loss factor of RO4835 and RO4350 are basically the same. The difference is that RO4835 is added with anti-oxidation filler on the basis of RO4350B, and has passed the automotive safety test, which is suitable for automotive anti-collision radar antenna design.