RO4835 High Frequency PCB

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RO4835 High Frequency PCB

Introduction
Welcome to our channel. My name is Ivy, the regional sales manager for Bicheng PCB. Today, we’re going to talk about a type of oxidation resistance PCB --RO4835 high frequency PCB.

All thermoset laminate materials, including FR-4, oxidize with time and temperature. Long-term oxidation can cause slight increases in the dielectric constant and dissipation factor of the circuit substrate.

Design and operating temperature have an impact on the pace of change and how well a circuit performs. Rogers has developed RO4835 laminate for applications requiring greater stability at high temperatures, which is much more resistant to oxidation than conventional hydrocarbon-based materials.

Now let’s look at the data sheet of RO4835.

RO4835 Typical Properties
RO4835 has a process DK of 3.48±0.05 at 10 GHz and 23℃, and a design DK of 3.66 for a wider frequency range of 8-40 GHz.

The dissipation factor is 0.0037 at 10 GHz and 23℃.

RO4835 has a thermal coefficient of dielectric constant (TCDk) of +50 ppm/℃ over a wide temperature range (-100℃ to 150℃), which is an excellent value for equipment used in variable temperature environments.

The volume resistivity and surface resistivity are both with high value, indicating good performance of insulation applications.

RO4835 has a high electrical strength of 30.2 Kv/mm (755 v/mil).

It shows good tensile modulus of 7780 MPa (1128 kpsi), tensile strength of 136 MPa (19.7 kpsi), and flexural strength of 186 MPa (27 kpsi).

RO4835 has excellent dimensional stability with a shift of less than 0.5 mm/m (mils/inch) after etching and exposure at 150℃.

The CTE value in X, Y, and Z directions is 10, 12, and 31 ppm/℃, respectively, within the range of -55℃ to 288℃.These low values reveal its stability over an entire range of circuit processing temperatures and reliable plated through holes.

RO4835 is high Tg material with value of greater than 280℃and decomposition temperature (Td) is as high as 390℃, which are useful for high-temperature applications.

It has a thermal conductivity of 0.66 W/m/K at 80℃.

In addition, RO4835 has a very low moisture absorption rate of 0.05% after 48 hours of immersion at 50℃, making it suitable for use in humid environments.

The density is 1.92 gm/cm³ at 23℃.

It also shows good copper peel strength of 0.88 N/mm (5 pli) after soldering floating 1 oz. ED copper foil.

Finally, RO4835 is UL 94 V-0 rated for flammability and is compatible with lead-free processes.

Property	RO4835	Direction	Units	Condition	Test Method
Dielectric Constant,εProcess	3.48±0.05	Z	-	10 GHz/23℃	IPC-TM-650 2.5.5.5 Clamped Stripline
Dielectric Constant,εDesign	3.66	Z	-	8 to 40 GHz	Differential Phase Length Method
Dissipation Factortan,δ	0.0037	Z	-	10 GHz/23℃	IPC-TM-650 2.5.5.5
Thermal Coefficient of ε	+50	Z	ppm/℃	-100℃to 150℃	IPC-TM-650 2.5.5.5
Volume Resistivity	5 x 108		MΩ.cm	COND A	IPC-TM-650 2.5.17.1
Surface Resistivity	7 x108		MΩ	COND A	IPC-TM-650 2.5.17.1
Electrical Strength	30.2(755)	Z	Kv/mm(v/mil)		IPC-TM-650 2.5.6.2
Tensile Modulus	7780(1128)	Y	MPa(kpsi)	RT	ASTM D 638
Tensile Strength	136(19.7)	Y	MPa(kpsi)	RT	ASTM D 638
Flexural Strength	186 (27)		Mpa (kpsi)		IPC-TM-650 2.4.4
Dimensional Stability	<0.5	X,Y	mm/m (mils/inch)	after etch+E2/150℃	IPC-TM-650 2.4.39A
Coefficient of Thermal Expansion	10 12 31	X Y Z	ppm/℃	-55℃to288℃	IPC-TM-650 2.4.41
Tg	>280		℃?TMA	A	IPC-TM-650 2.4.24.3
Td	390		℃?TGA		ASTM D 3850
Thermal Conductivity	0.66		W/m/oK	80℃	ASTM C518
Moisture Absorption	0.05		%	48hrs immersion 0.060" sample Temperature 50℃	ASTM D 570
Density	1.92		gm/cm3	23℃	ASTM D 792
Copper Peel Stength	0.88 (5.0)		N/mm (pli)	after solder float 1 oz. EDC Foil	IPC-TM-650 2.4.8
Flammability	V-0				UL 94
Lead-free Process Compatible	Yes

Our PCB Capability (RO4835)
This is our capability of RO4835 PCB.

Our PCBs come in a variety of layer counts including single-sided, double-sided, multi-layer and hybrid options.

There are ED copper and reverse treated copper for option.

Dielectric thicknesses of ED copper are available of 6.6 mils, 10 mils, 20 mils, 30 mils and 60 mils.

Dielectric thicknesses of RTC copper are available of 4 mils, 7.3 mils, 10.7 mils, 20.7 mils, 30.7 mils and 60.7 mils.

Copper weight for track lines includes 1oz (35µm) and 2oz (70µm).

The maximum PCB size we can provide is 400mm x 500mm; it can be a single board in the panel or the panel containing various possible designs.

The colour of solder mask in green, black, blue, yellow, red and purple etc. is available in house.

There are several options for pads protection, including immersion gold, HASL, immersion silver, immersion tin, bare copper, OSP and Pure gold etc.

PCB Material:	Hydrocarbon Ceramic Laminates
Designation:	RO4835
Dielectric constant:	3.48 ?(10 GHz)
Dissipation Factor	0.0037 (10 GHz)
Layer count:	Single sided, Double sided, Multilayer PCB, Hybrid PCB
Dielectric thickness: (ED copper)	6.6mil (0.168mm), 10mil (0.254mm), 20mil (0.508mm), 30mil (0.762mm), 60mil (1.524mm)
Dielectric thickness: (LoPro copper)	4mil (0.102mm), 7.3mil (0.186mm), 10.7mil (0.272mm), 20.7mil (0.526mm), 30.7mil (0.780mm), 60.7mil (1.542mm)
Copper weight:	1oz (35µm), 2oz (70µm)
PCB size:	≤400mm X 500mm
Solder mask:	Green, Black, Blue, Yellow, Red, Purple etc.
Surface finish:	Immersion gold, HASL, Immersion silver, Immersion tin, Bare copper, OSP, Pure gold plated etc..

A Piece of RO4835 PCB
We are currently seeing on screen a 60mil RO4835 PCB designed for point-to-point microwave applications with immersion gold plating.

RO4835 PCB has a wide variety of applications including, but not limited to, automotive radars and sensors, power amplifiers, phased array radars, and various other RF components.

Conclusion
Moreover, RO4835 material offers almost exactly the same electrical and mechanical properties as RO4350B laminates, which customers have successfully used for many years.

As a subset of the RO4000 hydrocarbon ceramic laminate family, RO4835 laminates are created to provide improved high frequency performance and affordable circuit fabrication. The end result is a low loss material that can be manufactured using common epoxy/glass (FR-4) techniques at a reasonable cost.

Well, thank you for reading. I’ll see you next time.