High-TG FR4 Printed Circuit Board

December 31st, 2020

If you work in Printed Circuit Board industry, you may know a normal PCB FR4-Tg is 130-140 degrees, the medium Tg is greater than 150-160 degrees, and High-TG FR4 Printed Circuit Board is greater than 170 degrees.
And what is a High-TG FR4 Printed Circuit Board? High-TG PCB is another name for a high-temperature FR4 PCB, it means the printed wiring boards designed to endure for extremely high-temperature. A Printed Circuit Board is defined as high-TG FR4 PCB if its glass transition temperature (TG) is higher than 170 degrees Celsius. High-TG FR4 will have better mechanical and chemical resistance to heat and moisture than standard FR4. The higher the TG value, the better the temperature resistance of the material, so High-TG FR4 is more and more popular particularly working in high power industry.
Best Technology can provide many different High-TG FR4 material for Rigid Circuit board, Typical High-TG FR4 PCB material including: ITEQ-IT-180A, ISOLA 370HR, ShengYi S1000-2 and etc.

Part of the inventory of raw material-1
Part of the inventory of raw material-2
Part of the inventory of raw material-3

From the following PCB picture, you can see the normal TG130 FR4 PCB substrate is not only softening, deformation, melting, as well as other phenomenon working under high temperatures, but also there is a sharp decline in electrical properties, which will effect on product life.

Solder mask blistering-1
、Solder mask blistering-2

If your FR4 Printed Circuit Board or PCBA board appear to above problems, then you should consider to use a High-TG FR4 Rigid Circuit Board. it may be catching your interest willing to understand a little bit more about High-TG FR4 printed circuit boards. Because High Tg Rigid Circuit board have a better stability at high temperatures, the substrate provides better heat resistance, mechanical and chemical stability for the circuit board.

BPM20396)

Properties/ Applications of high Tg PCB
With the rapid development of electronics industry, High-TG FR4 PCB is widely used in Uninterrupted Power Supply, precise instrument as well as industry. High-TG FR4 PCB material probably designed for the high functionality, high multi-layer development high-density circuit; higher heat resistance and high-density surface mounting technology (SMT). So, the demand on High-TG FR4 PCB material become more widely used PCB manufacturing.
What’s more, High TG material is also popular in LED lighting industry, because heat dissipation of LED is higher than normal electronic components, but same structure of FR-4 board is much cheaper than metal core PCB, such as aluminum PCB.
High-TG FR4 PCB materials have the following properties:
 Resistance to high temperatures
 Long delamination durability (aging of materials to consider for safety reasons)
 Low thermal expansion
Excellent PTH reliability
Good mechanical properties
High temperature durability
High value of thermal stress resistance
high temperature durability
long delamination durability
Low Z axis expansion (CTE)

BPM19308

Advantages of High-TG FR4 PCB
Higher stability: it will automatically improve the heat resistance, chemical resistance, moisture resistance, as well as stability of the device if increasing the TG of a printed circuit board substrate.
Bear high power density designs: high TG PCB will be a good solution for heat management if the device has high power density with quite high heat generation rate.
It can achieve with using a larger printed circuit board to change the design and power requirements of a device when reducing the heat generation of ordinary board, what’s more, it also can use the high TG PCB.
Ideal for multilayer & HDI PCBs: there will lead to high levels of heat dissipation because multilayer & HDI PCBs are more compact and have dense circuits. So high TG PCBs are often used for the multilayer & HDI PCBs so that it can make sure reliability in Printed circuit board fabrication.

BPM20005 TOP
BPM20005 BOT

 If your applications are in any danger of subjecting your PCBs to extreme temperatures or the PCB is required to be RoHS Compliant, it will be in your best interest to look into high-TG FR4 PCBs.
Come to contact Best Technology Co., Limited. for High-TG PCB assistance. we can help you determine if you need high-temperature printed circuit boards and direct you to which specific boards are likely to be useful for your design and application. If you are transitioning to RoHS or just need more information about the High TG laminates, just give us a call and we’ll be happy to accommodate you. contact us online right now.

What’s RT/duriod 5880?

December 1st, 2020

For PCB materials, you may have ever heard about many different kinds of materials such as the materials of FR4, Aluminum, Copper base and ceramic base.

But do you know what the duriod 5880 materials is?

Actually duriod 5880 is a kind of materials of the Rogers, it is the materials which is used for high frequency circuit board. RT 5880, which is famous for its low dielectric loss, low moisture absorption, and stable dielectric constant. The PCB made of duriod 5880 can be widely used in airborne and ground-based radar systems, millimeter wave applications, and space satellite transceivers.
Different with other kinds materials, the color of the RT 5880 materials is black.

Why this material can be used in such high end field? Let’s see below to know more information.

Excellent dielectric properties:
RT/duroid 5870/5880, as a new generation of high-frequency laminate, is made of polytetrafluoroethylene composite material (PTFE). At the same time, glass microfibers are randomly distributed in the material, which provides the greatest strength during the production and application of the circuit board.

High-frequency circuit design has strict requirements on the dielectric constant of the printed circuit board. RT/duroid 5880 has an ultra-low dielectric constant and remains the same in a very wide operating frequency range.

At 10GHz operating frequency, the measured dielectric constant is only 2.33/2.2, which is significantly lower than similar materials on the market. Therefore, from the perspective of performance parameters and production costs, the board is more suitable for high-frequency application design than similar products.

At the same time, under the same standard (f=10GHz), and the dielectric loss of the RT5880 is only 0.0012/0.0009. The extremely low dielectric loss makes it very suitable for high-frequency and the field of wide-band applications which requiring minimal dispersion and low loss.

In addition, the extremely low moisture absorption rate makes it an ideal choice for applications in high humidity environments. The moisture absorption rate of RT/duroid 5880 is only 0.02%, so it can meet the strict requirements of mechanical reliability and electrical stability in the complex microwave structure design, and it is also suitable for applications in high humidity environments.

With the continuous improvement of the operating frequency of high-frequency circuits, the requirements for the dielectric constant and dielectric loss of the circuit board are becoming more and more stringent. The excellent performance of RT/duroid 5880 in these two aspects can significantly improve the design of high-frequency circuits. Definity, improve circuit performance.

Easy to process and install
In this high-frequency design, in order to meet the requirements of electromagnetic shielding and compact design, printed circuit boards are often installed in various irregularly shaped cavity structures. Therefore, the PCB board must be designed in different shapes and suitable for production and Installation.

For RT/duroid 5880 laminate, which is easy to cut, trim and good for PCB manufacturing.

At the same time, it can resist all the solutions and chemical agents used in the process of etching and plating through holes, and it has a good performance of the cold and heat resistance.

The composite material RT/duroid 5880 can be covered with a laminated copper foil for some key electrical applications, and brass plates or copper can also be used as required.
Usually laminates of the RT/Duriod 5880, it can make double-sided copper clad with thicknesses ranging from 1/2 oz. to 2 oz./ft2 (8.5~70 ÎŒm) to meet most custome’s requirements for the thickness of copper foil.

Our company has focus on the PCB fabricationi for more than 15 years, we can make PCB with Rogers PCB with RT/Duriod 5880, as well as RO4003C and RO4350B with different thickness.
If you are interesting to know more and your PCB also want to made of RT/Duriod 5880, please feel freely to contact us for more information related.

The main factor affect the heat dissipation of Metal Core PCB

December 1st, 2020

various LED applications due to its good heat dissipation, do you know what factors can affect the heat dissipation?
As we all known, MCPCB(Aluminum/Copper/Stainless steel) is widely used in
One of the reasons is that Metal base board use special substrate material which is specifically formulated to improve the reliability of designs that run at higher than normal temperatures. Instead of serving strictly as a mounting surface for the various components, the substrate actively draws heat from the locations of hot-running components through to the opposite layer of the board where it can dissipate efficiently and safely, it’s the Dielectric Layer, which is the main factor affect the heat dissipation.

Some people may also mistakenly believe that the dielectric layer is thicker, the heat dissipation will be better. Actually the thickness of Dielectric Layer depends on the customer’s design requirements, it will not effect on heat dissipation. What affects heat dissipation is the material of the dielectric layer, also known as thermal conductivity.

Compare to Metal base board, FR4 PCB has low thermal conductivity, typically around 0.3W, while MCPCB has higher thermal conductivity, which include 1.0W, 2.0W, 3.0W, 7.0W, 8.0W.

In order to save the cost, not all boards need to use 3W dielectric layer. 1W is enough for 2835 or 3030 LED. High power LED like Cree need to use 3W.

If you have other questions about MCPCB, welcome to contact Tammy (Email:sales@bestpcbs.com), she will prove you professional suggestions and solutions.

Do the vias can be filled for ceramic PCB?

November 13th, 2020

As everyone knows for FR4 PCB, people like the vias to be tented or filled for some special applications.
Ceramic PCB is more and more popular because of the thermal conductivity is very high and very good for heat dissipation. Most of customers are going to make the PCB with ceramic material, includes Al2O3, AlN, BeO or Si3N4, etc.
So do the vias can be filled for ceramic PCB becomes the frequently asked questions (FAQ).
The answer is YES.
So what’s the material can be filled in vias for DBC/DPC alumina PCB/ Aluminium Nitride PCB?

The material can be solder mask, Dow Corning 1-4173 and copper/Cu.
Normally, customers want the vias/holes to be filled with copper.
Because copper can fill the vias very well and it is easier to do and it looks very good. Please see below photo.
The left one with filling with copper, the right one without filling copper

Why you need to fill the vias with copper?
1.Becuase if let the vias open, they will allow solder to flow through to opposite side of PCB during reflow, this causes bridging under components.
Filling the open vias/holes with copper can prevent from the solder pates into the vias.
2.If you need to pull vacuum around them and a hole would compromise that, so need to fill the vias.
There are also other purposes for filling the vias, if you need such ceramic board with filling the vias, please contact Coco in Best Technology sales@bestpcbs.com

What are the commonly used aluminum base materials? What’s the difference?

November 11th, 2020

Best Technology has more than 14 year experience for producing Metal core PCB, we have our own raw materials factory for MCPCB and we fabricate MCPCB in Shenzhen, so that customer various special requirements can be meet here.

Compared to copper and stainless steel, aluminum is the most economic option considering thermal conductivity, rigidness, and cost. And many of these aluminum alloys base have been divided into classes, the commonly used on MCPCB are AL1060, AL3003, AL5052 and AL6061.

Do you know the differences between these substrates? This blog will give a brief introduction for you.

1060 alloys
AL1060 are commercially pure, unalloyed aluminum, it’s soft, ductile, workability and exceptional corrosion resistance, making it suitable for hard-forming applications. It can be welded with any method, but it cannot be heat-treated. Its cost is the lowest of the four types.

3003 alloys
AL3003 use silicon, copper, and magnesium as the main alloying elements, oftentimes with supplemental nickel and beryllium. They are heat treatable, have high strength, good resistance to cracking and wear, and have good machinability.

Mechanical PropertiesMetricEnglish
Ultimate Tensile Strength200 MPa29000 psi
Tensile Yield Strength186MPac
Shear Strength 110 MPa16000 psi
Modulus of Elasticity68.9GPa10000 ksi
Shear Modulus25 GPa3630 ksi

5052 alloys
AL5052 use magnesium as their primary alloying element and are not heat-treatable, but it’s the highest strength alloy of the more non-heat-treatable grades. Its resistance to fatigue is better than most grades of aluminum and have a great surface aesthetic when anodized.
In our company, if not special request or notes, the default material we use is AL5052 after considering all the performance and cost.

Mechanical PropertiesMetricEnglish
Ultimate Tensile Strength228 MPa33000 psipsi
Tensile Yield Strength193 MPa28000psi
Shear Strength138 MPa20000 psi
Modulus of Elasticity70.3GPa10200 ksi
GPaShear Modulus 25.9 GPa25.9 760 ksi


6061 alloys

Mechanical PropertiesMetricEnglish
Ultimate Tensile Strength310 MPa45000 psi
Tensile Yield Strength276 MPa40000 psi
Fatigue Strength207MPa30000 psi
Shear Strength96.5MPa14000 ksi
Modulus of Elasticity68.9 GPa10000 ksi
Shear Modulus26 GPa770 ksi

AL6061 implement magnesium with silicon as their principal alloying elements. Their strength is improved with heat treatment. AL6061 is one of the most widely used aluminum alloys, it has high strength and superior corrosion resistance. Its weld-ability and formability make it suitable for many general-purpose applications.

Cost Comparison: AL1060 < AL3003 < AL5052 < AL6061

If you have other questions about MCPCB, welcome to contact Tammy (Email:sales@bestpcbs.com), she will prove you professional suggestions and solutions.

ENIG surface finish of FR4 Printed wiring board

November 4th, 2020

Continued to my last blog, do you know why we want to talk more for Gold surface finish of rigid Boards? I would like to take this chance to share more information for the capability from Best Technology.

Electroless nickel immersion gold (ENIG) is a type of surface plating used for printed circuit boards. It consists of an electroless nickel plating covered with a thin layer of immersion gold, which it can protects the nickel from oxidation. It is also used for welding and applied to contacts (such as keys, gold fingers on memory strips, etc
See attached complexity design for ENIG FR4 printed circuit board.

ENIG has several advantages over more conventional (and cheaper) surface plating such as HASL (solder), including excellent surface planarity (particularly helpful for PCBs with large BGA packages), good oxidation resistance, and usability for untreated contact surfaces such as membrane switches and other contact points. See the complex circuit boards design photo.

ENIG also does not wet as evenly or easily as HASL. In addition, ENIG is a costlier finish, but offers the best characteristics for printed circuit boards. The process requires the most steps compared to other common finishing types.
The thickness of Gold Best Technology conforms to IPC Standard IPC-6013.
Let us see the different for gold finish.

Gold-ENIG
The most important factor the gold serves as barrier and protectant to the nickel.
Advantages of ENIG

Immersion finish = excellent flatness
Good for fine pitch / BGA / smaller components from Samtec/Hirose/Molex
Wire bondable
Good heat dissipation
Long shelf Life (12 months in vacuum pack)

Disadvantages of ENIG
Expensive finish
Black Pad/Black Nickel concerns on BGA
Damage from ET (electronics test)
Signal Loss (RF)
Complicated Process

Gold-Hard Gold

Advantages of ENIG
Hard, Durable Surface
No Pb
Long shelf life

Disadvantages of ENIG
Very Expensive
Extra Processing/ Labor Intensive
Use of more solder Resist/Tape
Plating/ Bus Bars
Demarcation(delamination)
Difficulty with other surface finishes.

As an rich experience PCB manufacturer since 2006, Best Technology always improve its Rigid Circuit boards capability to meet customer requirements, If you have any question about the printed circuit boards (PCBs). Warmly welcome to send mail or call Best Tech.

Main types surface finish of FR4 Printed wiring board

November 4th, 2020

Printed Circuit Board surface finish is a coating between bare FR4 board and components. The main function for surface finish is to protect the exposed copper circuitry and provide a solderable surface when assemblingsoldering) the components to a copper clad PCB board.

Most of the Rigid Circuit board company can make several different types of surface finish. Best Technology as a leading custom FR4 printed circuit board manufacturer since year 2006, it could provide following different finish.
HASL
Lead-free HASL
Immersion Tin/Immersion Silver
OSP (organic Solderability Preservative)
Gold
ENIG (Electroless Nickel Immersion)
Hard Gold
Wire bonding Gold

As the surface mounts assembly service became more complex and needs to conform to new regulations like RoHS and WEEE. People maybe face the question how to choose a suitable surface finish for your FR4 Copper board?

Before decide to choose suitable surface of copper conductors circuit board, you may need to take the cost, RoHS, your components type, PCB assembly method, factory circuit fabrication capability, and rigid board circuit testability into consideration.
Basis on above information of copper foil PCB, we would like to make a explain PCB finish in detail, wish this may help when you make decision at circuit board design and manufacturing.

HASL/Lead Free HASL
It is a most popular surface finish, and the cost is low and easy to repairable, it is acceptable for simple SMT. But the surface is uneven, it is not suitable for fine pitch components and not good for plated through-hole(PTH). In other way, it is poor wetting.
Material different with same finish
HASL(standard):Typically Tin-Lead
HASL(Lead Free):Typically Tin-copper, Tin-Nickel, without lead
The thickness will conform to IPC 6012 class 2 standard

Advantages of HASL-LF
Excellent solderability
Inexpensive / Low cost
Widely Available and used
Easy reworkable
Allows large processing window
Long industry experience / well known finish

Disadvantages of HASL-LF
Uneven surfaces for printed circuit board
No good for fine pitch components from Samtec/Hirose/Molex
Thermal shock
Solder Bride for circuit board assembly
Plugged or reduced PTH’s
Not suited for < 20mil pitch SMD & BGA
Bridging on fine pitch
Not ideal for HDI products

Immersion Tin

Advantages
Flat surface
No Pb
Good for fine pitch / BGA / smaller components
Mid range cost for lead free finish
Press fit suitable finish
Good solderability after multiple thermal excursions
Easy reworkable

Disadvantages
Very sensitive to handling – gloves must be used
Tin whisker concerns
Aggressive to solder mask – solder mask dam shall be ≄ 5 mil
Not recommended to use peelable masks
Exposed tin on final assembly can corrode
Not good for multiple reflow/assembly process
Difficult to measure thickness

OSP (organic Solderability Preservative)
OSP(organic Solderability Preservative) same with HASL, lower cost but the OSP have flat surface, and it is not good for PTH components, sensitive and short shelf life, it is very easy come to oxidation.

Advantages
Flat surface
No Pb
Good for fine pitch / BGA / smaller components
Inexpensive / Low cost
Easy reworkable
Simple Process
Disadvantages
Not easy to measure thickness
Not good for circuit copper board plated through-hole(PTH)
Short Shelf Life
Maybe cause ICT issue
Exposed Cu on Final assembly
Handling sensitive– gloves must be used and scratches avoided

The above surface finish of Printed Wiring Board compared with Gold finish, the cost is corresponding cheaper, but in my coming blog, I would like mainly to explain Gold finish for printed circuit board fabricator with 13 years rich-experienced in FR4 PCB custom contract manufacturer.

If you have any question about the printed circuit boards (PCBs). Warmly welcome to send mail or call Best Tech.

What is PP (Prepreg) and CORE in a PCB?

October 30th, 2020

We all know that both Prepreg (PP) and CORE are important parts for the printed circuits board. And they are also very common on the PCB structure.

But what exactly they are? What’s the difference of a PP and Core for a FR4 PCB?

Prepreg, referred to as PP, it is a sheet material impregnated with resin and cured to an intermediate level (B-stage), known an insulating material for the PCB board.
As a prepreg material while the PCB production process, before lamination, it is mainly used as an adhesive material and insulating material for the inner conductive pattern of a multilayer PCB.

After the Prepreg is laminated, the semi-cured epoxy resin is squeezed away, starts to flow and solidify, bonding the multilayer circuit boards together, and forming a reliable insulator.

PP, it is placed between the two copper layers to isolate and make the two copper layers adhere. Below picture for you to see where the PP is on a PCB stack up.

And CORE, it is totally different as the Prepreg.

Core is with certain hardness and specified thickness, and with copper foil in both sides.
It is the basic material for making printed circuits boards, and the multilayer PCB board is actually made by pressing Core and Prepreg.
Sometimes, when people are talking about the Copper Clad Laminate (CCL), they also refer to the CORE.

And here is the major difference for the PP and Core:

  1. Prepreg is stayed with a semi-solid material in a PCB, similar to cardboard. But core is different, core is hard, similar to copper;
  2. Prepreg is similar to adhesive + insulator; while Core is the basic material of PCB, they have completely different functions;
  3. PCB Prepreg can curl, but PCB Core cannot bend;
  4. Prepreg is non-conductive, and the core has a copper layer on both sides, which is the conductive medium for a PCB board.

As an PCB manufacturer with more than 15 years experiences in China, Best Technology insists on using the best Copper Clad Laminate ( CCL) materials to make the PCB, no matter Prepreg or CORE, we will select the best FR4 materials for the PCB manufacturing, to make sure all the PCB boards we supplied to customers are with qualified materials and to be your best PCB suppliers in China.

What’s the Countersink and counter bore on a PCB drawing?

September 30th, 2020

Firstly, do you know what’s a countersink and counter bore?

By definition, a countersink is a stepped hole, which can allow the fasten parts head to sink fully to the parts.

With counter sink on your design, the tapered head of a screw can sit flush with the top of the laminate, commonly countersink is used to install bolts or other connecting parts.

Below is the example for the hole drawing and picture for a countersink:

Picture: counterbore holes attributes

To drill your countersunk holes accurately in our PCB fabrication plant, the following information is need to be defined when you supply the PCB drawing for us to make the PCB:

  • Which side of the board is the countersink hole should be drilled, on top or bottom?
  • Is the sink and shaft to be through plated or non-plated?
  • Taper angle or countersink angle. 82°, 90°,120° etc.
  • Countersink diameter of top
  • Countersink diameter of bottom (body)
  • Depth of the countersink is to be drilledthe height of the screw to determine the countersink depth.

By comparison, a counterbore makes a flat-bottomed hole and its sides are drilled straight down. This is usually used when a fastener such as a bolt or cap head screw is required to sit flush with or below the level of a surface.

Below is the drawing and picture for a countersink.

Same as the countersink, the counterbore holes attributes drawing is needed to supply with your PCB drawing when fabricate the counterbored holes. But for counterbore on PCB, because the sides of the hole are always parallel, there is no need to specify the angle.

With below drawing, believe it will be more helpful for you to understand the difference for a counter sink hole and counterbore on the printed circuits board.

If need to have any question regarding the counter sunk or counter board on a PCB drawing, please contact us feel free.

What are the factors affecting cost of the MCPCB?

September 29th, 2020

Best Technology considers all the factors affecting the cost of MCPCB production while formulating final cost structure. Many customers contact us to know the factors which affecting the price. The factors are Size & Thickness, Number of layers, Cu Thickness, Thermal Conductivity, Surface Finishing etc.

Size & Thickness: Since larger boards require more material.

As you know, 1.6mm is the standard thickness, if you choose non-standar thickness (Thicker or thinner than 1.6mm), sometimes the price will need to increase, it depend on the layers of your MCPCB.

The different number of layers and manufacturer technologyIt’s the main factor for affecting the manufacturing price, therefore the circuit board designing is done in such a manner that it comprises a minimum number of circuit layers. 

Thermal Conductivityis one of the most important performances of MCPCB, the higher the thermal conductivity is, the more expensive the price is. At present, the highest thermal conductivity we can provide is 8W/m.K, the commonly used thermal conductivity is 1-3W/m.K

Cu Thickness: The cost will be more expensive if the copper is thicker. We can provide 0.5 OZ, 1.0 OZ, 2.0 OZ, 3.0 OZ, up to 10 OZ.

Surface Finishing: The common Surface Finishing for MCPCB is HASL_LF, OSP  ENIG (The normal thickness of gold is 1u’’). ENIG is more expensive since the gold is expensive and it with good performance for protecting the surface from oxidized.

ENIEPIG is good for wire bonding (the normal thickness of gold is 3u”).

We always strive to formulate a competitive price structure for our customers, this enables to have a considerable reduction in the total prices and deliver superior quality services to them. If you would like to know more about MCPCB, please directly contact our sales Tammy