High frequency PCB fabrication

High frequency PCB is widely used in RF and Microwave PCB. High frequency PCB materials are different from conventional FR4 materials. Most of them use PTFE &Teflon materials. Good electrical properties and low signal loss are the basis.

High frequency PCB needs special materials to realize the high frequency signal provided by this type of printed circuit board. Many PCB designers choose Rogers dielectric material because of its lower dielectric and signal loss, lower circuit manufacturing cost, and more suitable for rapid turnover prototype application.

In addition to selecting the right PCB material and determining the correct Er value, the designer should also consider the conductor width and spacing, substrate constant, and other parameters. The highest level of process control must be used to specify and implement these parameters precisely.

Rocket PCB is an experienced full-service high frequency PCB manufacturer, which can provide reliable and excellent high-frequency PCB fabrication services. Evaluate your requirements according to your design, rich variety of high frequency materials, mature high frequency PCB manufacturing experience.

What is high frequency PCB?

High frequency PCB board (HF PCB) refers to the special circuit board with high electromagnetic frequency, which is used for high frequency (frequency greater than 300MHz or wavelength less than 1m).  Generally speaking, high frequency board can be defined as a circuit board with a frequency above 1GHz.  Substrate materials need to have excellent electrical properties and good chemical stability.  With the increase of power signal frequency, the loss requirement on the substrate is very small, so the importance of high-frequency material is highlighted.

High frequency PCB board with induction heating technology has been widely used in the communication industry, network technology, and high-speed information processing system, which meets the requirements of many high-precision parameter instruments. A reliable high-frequency circuit board, in the actual production, provides great help.

What are the advantages of such a powerful high frequency pcb?

High efficiency

High-frequency circuit board with a small dielectric constant will also have a small loss, and the advanced induction heating technology can meet the demand of target heating, and the efficiency is very high. Of course, while focusing on efficiency, it also has the characteristics of environmental protection, which is very suitable for the development direction of today's society.

Fast

The transmission speed is inversely proportional to the square root of the dielectric constant, which means that the smaller the dielectric constant, the faster the transmission speed. This is the advantage of high-frequency PCB, it uses special material, not only to ensure the characteristics of small dielectric constant but also to maintain stable operation, which is very important for signal transmission.

A large degree of regulation

High-frequency circuit boards, which are widely used in various industries for the heating treatment of precision metal materials, can not only realize the heating of components with different depths but also focus on heating according to the local characteristics.  Whether the heating methods of surface or deep level, concentration or dispersion can be easily completed.

It is well tolerated

The dielectric constant and medium have certain requirements on the environment.  The use of the circuit board will be seriously affected by humid weather. The high-frequency circuit board made of materials with low water absorption can challenge this environment.  At the same time, it has the advantages of resistance to chemical corrosion, moisture resistance, high-temperature resistance, and great peel strength, which makes the high-frequency circuit board play a strong performance


Processing characteristics of high-frequency PCB

  • Impedance control requirements are relatively strict, relative to the line width control is very strict, with the general tolerance of about 2%.

  • Due to the special material, so the adhesion of PTH copper is not high.  It is usually necessary to roughen the via hole and surface with the help of plasma treatment equipment to increase the adhesion of PTH hole copper and solder mask ink.

  • Do not grind the board before the solder mask, otherwise, the adhesion will be very poor, only use a micro etching solution to roughen.

  • Most of the materials are made of polytetrafluoroethylene, and there will be a lot of burrs formed by ordinary milling cutters, so a special milling cutter is needed.

  • Its physical properties, precision, technical parameters requirements are very high, commonly used in automotive anti-collision systems, satellite systems, radio systems, and other fields.



Application field of high-frequency PCB


  • Mobile communication products, intelligent lighting system

  • Power amplifier, low noise amplifier, etc

  • Power divider, coupler, duplexer, filter, and other passive components

  • In the fields of automobile anti-collision systems, satellite systems, and radio systems, the high frequency of electronic equipment is the development trend.

 



Classification of high frequency PCB material

Powder ceramic filled thermosetting materials

A. Manufacturer:

Rogers 4350b / 4003c

Arlon 25N / 25FR

Taconic TLG series

B. Processing method:

The processing process is similar to that of epoxy resin/glass woven fabric (FR4), but the board is brittle and easy to break.  When drilling and punching, the service life of drill bit and Gong knife will be reduced by 20%.


PTFE material

A: Manufacturer

1.  Rogers Ro3000 series, RT series, and TMM series

2.  Arlon AD / AR series, isoclad series, and cuclad series

3.  Taconic RF series, TLX series, and TLY series

4.   F4B, F4BM, F4BK, TP-2 of Taixing microwave

B: Processing method

1. Cutting: the protective film must be reserved to prevent scratch and indentation

2. Drilling:

  • Use a new drill bit (standard 130, presser foot pressure is 40psi

  • The aluminum sheet is the cover board, and then use 1 mm melamine backing board to tighten the PTFE board

  • After drilling, blow out the dust in the hole with an air gun

  • With the most stable drilling rig, the drilling parameters (basically, the smaller the hole, the faster the drilling speed; the smaller the chip load, the smaller the return speed)

3. Hole treatment

Plasma treatment or sodium activation treatment is beneficial to pore metallization

4.  PTH copper deposition

  • After micro etching (the micro erosion rate is controlled by 20 micro inch), the board is fed from the oil cylinder after PTH pulling

  • If necessary, the second PTH will be passed, and the board can only be fed from the predicted cylinder

5. Soldermask

  • Pretreatment: acid washing, not mechanical grinding

  • After pretreatment, bake the board (90 ℃, 30min), brush green oil to solidify

  • Three stages of baking: 80 ℃, 100 ℃ and 150 ℃ for 30min respectively (if oil is found on the surface of the substrate, rework can be done: wash off the green oil and reactivate it)

6. Gong board

Lay the white paper on the surface of the PTFE board line, and clamp it with FR-4 baseboard or phenolic baseboard with a thickness of 1. 0 mm to remove copper:

The rough edge of the backboard of the Gong board needs to be carefully scraped by hand to prevent damage to the base material and copper surface, and then separated with sulfur-free paper of a certain size, and visual inspection should be carried out to reduce the burr.  The key point is that the removal effect of the Gong board process should be good.

 

List of common high speed and high frequency PCB material parameters

List of common high speed and high frequency PCB material  parameters
supplierboardResin   typeMaterial   propertiesprice   indexapplication   area Evaluation   conclusion
DKDFTgTdZ-CTET288Water   absorption
(1GHZ)(1GHZ)(DSC)(TGA)(50-260)(min)(%)
SYSTS7439(EL230T)/3.80.0045200℃380℃/>60min0.08%/Network   equipment, measuring equipment
S7240/3.90.005200℃360℃2.00%>60min0.10%/Backplane,   server, router
EL190T/4.30.011220℃345℃/20min///
FL700/3.70.003205℃350℃/20min///
FL700LD/3.50.0025205℃350℃/20min0.24%//
ITEQIT200LK/3.80.01200℃350℃2.50%30min0.10%//
IT150DA/3.560.0047172℃350℃3.81%30min0.12%//
ISOLAFR408FR4 +   hydrocarbons3.770.011180℃360℃3.50%200.15%//Board   thickness ≤ 2.0mm, pitch ≥ 0.8mm
FR408HR3.680.009200℃370℃2.80%300.06%3.2/Board   thickness ≤ 3.0mm, pitch ≥ 0.8mm
IS680-345/3.450.0035192℃376℃2.90%60min0.10%5/
NECLON4103-13CE   (cyanate ester)3.70.009210℃365℃3.40%100.10%3.9Automotive,   aviation, defense, communications infrastructure, semiconductors, high-speed data
N4103-13EP3.70.009210℃350℃3.50%10+0.10%3.9
N4103-13SI3.40.008210℃365℃3.50%10+0.10%3.9
N4103-13EPSI3.40.008210℃350℃3.20%10+0.10%4.3
Mercurywave 9350/3.70.004200℃360℃2.50%40min0.15%/
PanasonicM4   (R5725)FR4+PPO3.80.005175℃362℃2.80%300.14%4
M6 (R5775K)PPO3.60.002185℃410℃/60min0.14%5.8
TUCTU-872/SLK/3.80.008200℃340℃/20min/3.3/
TU-872/SLKSP/////////3.3/
EMCEM828/3.70.008170℃380℃/30min///
HITACHIFX-2/3.50.002180℃350℃/60min0.03%10.3/
MCL-LX-67/3.50.005235℃///0.03%8.4/
ROGERSRO4350BHydrocarbons   + ceramics3.480.0031280℃390℃0.63%60min0.06%8.3Satellite   TV LNB, microstrip line, power amplifier
RO3003PTFE   ceramics30.0013/500℃//<0.1%16.7Communication   satellite, backplane
RO4533PTFE   ceramics3.30.0025/500℃//<0.02%25Cellular   base station antenna
RO3730PTFE   ceramics30.0016/500℃//0.04%25Base   station antenna, the satellite transmission antenna
ARLONTC350PTFE   ceramics3.50.002/567℃1.20%>60min0.05%6.5Power   amplifier, filter, connector
AD300CPTFE   ceramics2.970.002/555℃/>60min0.06%8.3Base   station antenna, power amplifier
CLTE-ATPTFE   ceramics30.0013/529℃/>60min0.03%16.5Car   radar, sensor
Multiclad/3.70.004205℃432℃1.20%>60min0.10%4Backplane,   power amplifier, receiver
TACONICRF35A2PTFE   + glass fiber3.50.0011/528℃2.65%/0.02%18Wireless   link, transmitter, power divider, combiner, filter, base station antenna
TLY-5PTFE   + glass fiber2.20.0009////<0.02%/
TSM-30PTFE   + glass fiber30.0015////0.03%36
TLX-8PTFE   + glass fiber2.450.0015////<0.02%/
RF35PTFE   + glass fiber3.50.0018////0.03%14
TLC-30PTFE   + glass fiber30.028////<0.02%/


List of different high frequency PCB materials corresponding to dielectric constant (Df) in different stages





List of high frequency and high speed PCB materials with low dielectric loss (DK) in different stages



Please refer to our PCB material list for more PCB material selection, https://www.rocket-pcb.com/pcb-materials


High-frequency PCB Process flow

1.  Npth PTFE board processing process

Cutting - Drilling - dry film - Inspection - etching – etching checking - soldermask- character - HASL- forming - testing - final inspection - Packaging - Shipping

2.  PTFE board processing flow of PTH

Cutting - Drilling - Plasma treatment or sodium naphthalene activation treatment-PTH- Plate plating - dry film-Inspection- pattern plating-etch-inspection-soldmask-silkscreen-HASL-profiling-test-FQC-packaging-shipping

 

Difficulties in high frequency board processing

1. Copper deposition: the hole wall is not easy to deposite copper

2. Control of line gap and sand hole in graph rotation, etching and line width

3. Green oil process: green oil adhesion, green oil foaming control

4. The scratch on the board surface is strictly controlled in each process

 

The advantage of Rogers PCB materials prototyping and costs

1. The commonly used high-speed boards are as follows:

  • Rogers Rogers: ro4003, ro3003, ro4350, ro5880, etc.  

  • TUC: Tuc862, 872slk, 883, 933, etc. 

  • Panasonic: megtron4, megtron6, etc. ,

  • Isola: fr408hr, is620, is680,

  • Nelco: n4000-13, n4000-13epsi,

  • Dongguan Shengyi, Taizhou Wangling, Taixing microwave, etc

Rogers circuit board is very popular in the market.  Rogers brand materials are mostly used in the high-frequency communication industry. 


2. Main substrate of Rogers circuit board

Rogers 4350b is one of the boards imported from Rogers, USA, which is mainly used in the production of high-frequency circuit boards. In addition, there are also ro4350b, ro4003c, rt5880, ro3003 and ro3010. For detailed parameters, please refer to the materials data sheet on Rogers's website.


Rogers high-frequency board is usually mixed with special materials

Rogers and special materials, copper-based materials + Rogers become Rogers hybrid copper substrate PCB, and ceramic base + FR4 are Rogers communication hybrid base board, etc,


3. The cost of Rogers circuit board prototyping

Rogers high-frequency board prototyping costs note that there are a few aspects of the composition,

  • Rogers base material model

  • The process requirement, the more complex the process, the more expensive the price

  • The number of layers, the higher the number of layers, the price will increase accordingly, and the difficulty of making boards will also increase

  • In addition, there are engineering costs.  If there is an urgent need, there are also urgent costs, etc


High frequency PCB manufacturing in Rocket PCB

Rocket PCB is a professional high-frequency PCB board manufacturer. Rogers high-frequency PCB prototyping is more done in the high-frequency board.  In addition, there are other high-frequency materials, such as tekonik high-frequency board, PTFE high-frequency board, Arlon, etc.

Rocket PCB has 20 years of PCB production experience, 300 skilled technical teams, professional PCB and PCBA quality inspection team, to ensure product quality, delivery on time, high-frequency board as soon as 48 hours delivery, 24 hours uninterrupted quotation, timely solve customer problems. Please consult rocket PCB for more details.



Actual Product Cases


Basic product  information
Number of layers8L 
Thickness of finished board 2.0±0.2mm 
Finished product size11.81×6.44inch 
Aspect ratioThrough hole 7:1, blind hole 0.63:1
Board material RO3003+RO4835LowPRo
    + s1000-2 hybrid 
Minimum drill tip/Finished hole size 0.275/0.2mm 
Minimum line width/Line spacing0.102/0.114mm 
Back drillStub control 8mil
Impedance tolerance ±10%
surface treatmentImmersion Silver 
HDI design; Back drilling;Mixed compression of three  materials; Impedance control; Pofv process.77GHz
    Radio frequency microwave radar


Basic product information

Number of layers8L 
Thickness of finished board 2.0±0.2mm 
Finished product size11.81×6.44inch 
Aspect ratioThrough hole 7:1, blind hole 0.63:1
Board material MT-77+RO4835LowPro+S1000-2 mixed pressure
Minimum drill tip/Finished hole size 0.275/0.2mm 
Minimum line width/Line spacing0.102/0.114mm 
Back drillStub control 8mil
Impedance tolerance ±10%
Surface treatmentImmersion Silver
   
HDI (L1-L3 macroporous laser); Back drilling; Mixed compression of three materials; Impedance control; Pofv process
    77GHz RF microwave radar
   



Basic product information
Number of layers10L 
Thickness of finished board 1.4±0.14mm 
Finished product size15.66×12.24inch 
Aspect ratioThrough hole 5.4:1, blind hole 0.93:1
Board material Ro3003 + r5785 mixed pressure
Minimum drill tip/Finished hole size 0.25/0.2mm 
Minimum line width/Line spacing0.13/0.1mm 
Back drillN/A 
Impedance tolerance ±10%
surface treatmentOSP 

Large size panel design;HDIMicrowave RF board; High frequency mixed pressure ,  electroplating hole filling; 

steam Car board (77GHz RF microwave radar )   


Basic product information
Number of layers8L 
Thickness of finished board 1.6±0.16mm 
Finished product size5.98*3.94 
Aspect ratioThrough hole 6:1, blind hole 0.58:1
Board material Mixed pressure of ro4835 + it180a(n + n structure)
Minimum drill tip/Finished hole size 0.25/0.2mm 
Minimum line width/Line spacing0.102/0.114mm 
Back drillN/A 
Impedance tolerance ±10%
surface treatmentImmersion Nickel gold
   
HDI, N + n mechanical blind hole; Radio frequency microwave; High frequency mixed pressure;
    Pofv process; Impedance control.24GHz RF microwave    



Basic product information
Number of layers6L 
Thickness of finished board 1.6±0.16mm 
Finished product size6.79×5.08inch 
Aspect ratioThrough hole 5.9:1, blind hole 0.58:1
Board material RO4835+IT180A 
Minimum drill tip/Finished hole size 0.25/0.2mm 
Minimum line width/Line spacing0.102/0.114mm 
Back drillN/A 
Impedance tolerance ±10%
surface treatmentImmersion Nickel gold 

HDI 

POFV 

impedance

Mixed pressure

24GHz radio

Frequency microwave


Basic product information
Number of layers8L 
Thickness of finished board 1.64±0.17mm 
Finished product size13.78*12.81 
Aspect ratioThrough hole 6.1:1, mechanical blind hole 1.17:1
Board material S7135 + it180a mixed pressure
Minimum drill tip/Finished hole size 0.25/0.2mm 
Minimum line width/Line spacing0.5/0.127mm 
Back drillThree kinds of mechanical PTH depth control drilling
Impedance tolerance N/A 
surface treatmentImmersion Silver
   
Large panel; Mechanical blind hole plate; Microwave radio frequency; Mixed pressure, different depth back drilling
   


Basic product information
Number of layers14L 
Thickness of finished board 2.5±0.25mm 
Finished product size21.73*10.91inch 
Aspect ratio9.8:1 
Board material TU-862HF+S7135 
Minimum drill tip/Finished hole size 0.25/0.2mm 
Minimum line width/Line spacing0.114/0.114mm 
Back drillDouble side back drilling, stub value in the same hole  control 8 mil
Impedance tolerance ±10%
surface treatmentImmersion Nickel gold
   
    Oversize
    Different depth back drilling
    8mil Stub
    Mixed pressure
    PODV
    5G PA product
   




Related reading

How to choose high speed and high frequency PCB material

Chat Online 编辑模式下无法使用
Chat Online inputting...
Thank you for your attention. Please kindly describe your question first, or please send your inquiry to our email sales@rocket-pcb.com, we will reply to you ASAP. Skype account: hans.hu@rocket-pcb.com welcome to consult!