Archive for March, 2020

Measures China took to fight against the COVID-19

Tuesday, March 31st, 2020

China’s fight against COVID-19 epidemic has achieved victory at this stage. Infected patients were found in 337 cities in China but now only 28 cities remaining patients in cure. So far till March 31st, there were 82545 confirmed cases in China, while 76225 cured and only 3006 remaining now. Most importantly, many of the areas finds only one figure number increase and others stop increasing for quite some days. If the first half of COVID-19 fighting is inside China national territory, the second half will be on the international stages while noticeable growth on COVID-19 infected cases are spreading all over the world now.

corona virus updates
corona virus updates

Best Technology has been collecting the measures in China on epidemic controls so in order to provide a more objective and useful reference for overseas professionals which we hope they could refer to and protect better themselves from the COVID-19.

Governmental Measures

During the height of the outbreak, trains didn’t stop at the disease’s epicenter, Wuhan

Wuhan trains
Wuhan trains

Trains, as well as other tightly packed forms of transportation, can serve as vectors of illness. The more people, the more closely packed, and the more poorly ventilated the space, you can imagine that’s a bad situation because there are a ton of people, they’re in very close quarters, and they’re a totally captive audience. Cutting off transportation was considered on the top three measures to contain the spread of the virus.

China built new hospitals in a rush, with workers toiling night and day to get them done.

China Newly-built Hospitals
China Newly-built Hospitals

China built two new 1,000-1,300-bed hospitals to fight the corona virus, one created in six days, and the second in 15 days, using prefabricated modules.

Corona virus testing was easily accessible and free

Corona virus testing
Corona virus testing

In China, patients who were confirmed to have the corona virus were either sent to an isolation center or hospital. The government also made clear that testing for the new virus was free, and COVID-19-related charges that weren’t covered by a person’s insurance would be paid for by the government.

The country implemented large-scale contact tracing in the early 2000s

Contact tracing
Contact tracing

During the SARS outbreak in 2002-2003, China set up large-scale surveillance systems that included contact tracing, a front-line public-health strategy that involves identifying and following up with people who may have come into contact with an infected person.

The country postponed non-urgent medical care and moved many doctor’s visits online. Not all patients were given the critical care they needed during the outbreak, though

Doctor's online visit
Doctor’s online visit

In China, elective surgeries and other non-critical doctors’ visits were delayed, and many medical services were moved online. Someone in one place said 50% of their consultations are now done online; they just moved a whole bunch of what was normally done physically online to be able to keep the regular health services going.

Centers for Disease Control exploring a way of therapeutic plan combing Traditional Chinese medicines and Western medicines.

 Traditional Chinese medicines treatment
 Traditional Chinese medicines treatment

The combination of Traditional Chinese medicines and Western medicines had been proven effective on the SARS fights. Doctors of traditional Chinese medicines had volunteered for consulting and participating into the virus fights.

China used technology that aims to trace every single COVID-19 case

Civilian Measures

Traditional epidemic prevention manufacturers speed up and similar production lines integrating to make more necessary products

mask production line
mask production line

Many medicinal and pharmaceutical substances manufacturers launched automation assemble lines and increase manpower to speed up the mass production of necessary drugs, masks, ventilators to meet the huge consumption during virus fighting. Many of these companies arranged 24-hour shifts for maximizing the production.

Meanwhile other manufactures such as automotive OEM had change their assemble line into masks productions machines.

At the blast of COVID-19, returning Chinese carrying back epidemic products from overseas as much as they can

epidemic products brought by overseas Chinese
epidemic products brought by overseas Chinese

 Returning travelers carried extra masks on their flights back to China and donated them to the hospital and governments in need. Some overseas Chinese unions also had helped ordering these products and sending to China.

Chinese citizens did their part to curb the disease’s trajectory on an individual level, too, though we may never know the true scale of their complaints or sacrifices in this outbreak.

China's road
China’s road

In contrast to reports in the US of people clamoring over the last hand-sanitizer, the attitude of people in China was that they were all in this together. People stay at home for self-quarantine, lockdown and response to the postpone returning to work and school.

People who thought they might have the corona virus could go to one of the nation’s many fever clinics

fever clinics
fever clinics

People who thought they had the novel corona virus in China would often be sent to a special fever clinic, which have been widespread since the country dealt with an aggressive SARS outbreak in 2002. Their temperature would be taken, and they’d discuss their symptoms, medical history, travel history, and any prior contact with anyone infected with a doctor.

If necessary, patients might receive a CT scan, which is one way to do an initial screening for COVID-19. Each machine did maybe 200 a day. 5-10 minutes/scan. A typical hospital in the West does one or two an hour.

People quickly shifted jobs in order to assist during the outbreak


When it came to the non-medical response, there was a nationwide sense of solidarity with Hubei. Other provinces sent 40,000 medical workers to the center of the outbreak, many of whom were volunteers.

Workers in transportation, agriculture, and clerical positions were encouraged to new positions such as delivery, courier and epidemic prevention manufacturing, too.

While staying home, it’s been relatively easy for Chinese people to get extra food and supplies

Enough food
Enough food

China essentially mandated a country-wide shut down, demanding that every Chinese resident stay home until the curve was flattened. But in West, unlike China, a country-wide shutdown would be difficult to enforce.

Fifteen million people had to order food online. It was delivered. Yes, there were some screw-ups. But few said: every now and again there’s something missing from a package, but food supply is pretty much normal via ordering online.

We know it’s difficult for most of people around the word to find protection devices, such as face mask, Non-surgical isolation gown , Medical gowns, protective coveralls, Surgical Cap, Surgical Dress , Medical gloves, Safety Goggles, Surgical Helmet, infrared thermometers, please contact our sales, we will be glad to support you.

How to Choose Thick or Thin FR4 PCB?

Monday, March 30th, 2020

If you’ve ever made a pie with your kids, you know that the thickness of your crust is important. Too thin, and the pie falls apart into a mess of filling. Too thick, and you might as well be chewing on a loaf of bread. Getting the thickness just right is what makes a pie worth eating.

Even though PCB substrate materials are non-conductive and do not carry current, the board material still affects the electrical performance. FR4 PCB substrate is widely used, and a thorough understanding of this material is very necessary.


FR4 Thickness Design Considerations

If you start your design process by choosing the correct board thickness, you will avoid to redesign later. A number of factors are influenced by the board thickness. Before you start designing your board, think about the following design issues:

Form factor and flexibility: Does your PCB have a strict form factor requirement? Thinner boards tend to be used in smaller devices and can flex more than a thicker board. A more flexible board may be unusable with a pick & place machine. Electrical connections in flexible boards can also break unless they have some mechanical support.

Components and connections: Will the device have any components that require the Printed Circuit Board to have a specific thickness? Components like USB edge connectors and some through-hole components require PCB in correct thickness. BGA connectors generally require thicker boards.


Impedance matching: Traces on adjacent layers in multi-layer boards form a capacitor, and the layer thickness and its dielectric constant determines the equivalent capacitance. Impedance matching is critical, and the capacitance must be taken into consideration when designing the board. This is especially true in HDI PCB.

High-speed devices: If you are working with a high-speed device, FR4 is always not the best option, and some other material should be used instead. FR4 PCB could be used in high-speed devices when the layers are coated with high-speed laminates. These laminates offer significantly improved electrical performance over standard FR4, and generally a combination of FR4 and a high-speed laminate may be preferable to an alternative material.

RF losses: FR4 tends to have higher losses than other PCB materials that are specialized for RF applications. Traces on FR4 will have larger attenuation at RF frequencies than other specialized materials for a given board thickness. The board thickness also changes the effective dielectric constant of the board, which then changes the required impedance matching in RF circuits.

Thermal and Reliability Considerations

All materials expand at higher temperatures, and the thermal expansion coefficient must be taken into consideration when choosing the board thickness. The thermal expansion coefficient of FR4 changes drastically above the material’s glass transition temperature (140℃). The board can become electrically and mechanically unstable when the board operates above the glass transition temperature.

The reliability of the trace materials, laminate materials, and solder joints on a PCB laminate are determined by the resistance to thermal cycling. When the thermal expansion coefficients of the different materials are mismatched, fatigue occurs after repeated thermal cycling. Copper plating in vias and solder balls are especially vulnerable to damage under thermal cycling.

This is a greater problem in thick FR4 PCB with high aspect ratio vias. Plating damage in through-hole vias, lifted pads, and cracked surface resin can occur under the stress caused by thermal cycling. A thicker board will have a larger expansion magnitude for a given via aspect ratio, resulting in more damage to the board and the electronic components. Thermal stresses can be huge when an FR4 PCB runs above the glass transition temperature.

Volumetric expansion is also critical in rigid-flex FR4 PCB. Thermoplastic adhesives with low glass transition temperatures and high Z-direction expansion coefficients can exhibit very large volume expansion at high temperature. Z-direction expansion in these situations can be as large as 500 ppm/℃.

Even though a thicker FR4 PCB has greater thermal mass and can dissipate more heat from electronic components, there is also the potential for more damage due to thermal expansion. Therefore, how to choose between a thick and thin FR4 PCB that satisfies all other requirements, the thinner board may be a better choice if the FR4 PCB will undergo thermal cycling frequently.

If you have any comments. queries or suggestions on this, welcome to contact us.

How to choose the thickness of copper on PCB

Tuesday, March 24th, 2020

As a general rule, this thickness of copper foil for single-sided PCB and double-sided PCB is approx.35um(1.4mil). There is also another specification, which is 50um and 70um. The surface thickness of multilayers PCB is 35um(1oz(1.4mil)) generally, and the inner layer has a thickness of 17.5um(0.7mil). 70% of PCB uses the copper foil thickness of 35um. This is based on PCB purpose and signal voltage as well as current. In addition, for PCB requiring large current, copper thickness of 70um or 105um will be used, and 140um is also used in some cases.

heavy copper pcb
heavy copper pcb

People often use OZ to represent copper thickness. 1OZ stands for the thickness of 1OZ copper covered on the area of 1 square feet evenly. I.e. approx. 1.4mil. The weight of unit area is used for representing the average thickness of copper foil. I.e. 1oz=28.35g/ FT2(FT2 stands for square feet, 1 square feet=0.09290304 square meter).

For heavy copper PCB, if the substrate has a thickness of 1 to 3mm, then the thickness of composite copper foil will be approx.35um. If the substrate has a thickness of less than 1mm, then the thickness of composite copper foil will be 18um. If the substrate has a thickness of above 5mm, then the thickness of composite copper foil will be 55um.

heavy copper pcb
heavy copper pcb

The thickness of copper foil(wiring width) will influence current. Even though there is a formula to directly calculate the largest current loading capability of copper foil, things will get more complex when designing wiring. In this case, safety should be fully taken into consideration during design.

Copper foil will have different thickness, if there are different purposes. General 0.5OZ, 1OZ and 2OZ copper foil are most widely used for consumption and communication products. The thickness of copper foil above 3OZ belongs to heavy copper products, which are widely used for products with large current, such as high pressure products, and power supply board.                                               

This is all about how to choose proper copper thickness during your project. Hope this is helpful to you. If you are still confused, please contact Best Technology. We have online customer services for 24 hours.

Aluminum PCB LED Strip

Friday, March 20th, 2020

With the development of LED technology, LED power keeps increasing. This is closely related to heat dissipation. In order to resolve heat dissipation of LED with big power, aluminum-based copper-clad laminate is highly applied in led strip field.

Aluminum PCB(metal-based heat dissipation board) is a kind of unique metal-based copper-clad laminate. It has good head conductivity, electrical insulation and machining performance. Single-sided aluminum pcb consists of three layers of structures:circuit layer(copper foil), insulation layer and metal-based layer. Circuit layer requires large current-carrying capability, so we should use thick copper foil(generally 35um to 280um). The insulation layer for heat conduction is the core technology of aluminum pcb. It is general composed of special polymer filled with special ceramic. Small heat resistance, excellent viscoelasticity and anti-aging are all its advantages. And it is also able to bear mechanical and heat stress. Metal-based layer is the supporting component of aluminum pcb, and it needs to have high heat conductivity, so we generally use aluminum board, or copper board(which can provide higher conductivity). And it is suitable for regular machining such as drilling, punching and cutting. Techniques include gold plating, solder levelling, osp, ENIG, lead-free ROHS and so on.


Aluminum pcb is commonly seen in LED products and has two sides(the front side and the reverse side). The white face is used to solder LED pin, and the other face presents natural color. It is generally painted with thermal conductivity paste and then contacted with heat conduction part. LED aluminum pcb is mainly used in power amplified mixed integrated circuits for STK series, motor cycles, automobile and electronics field.

There are many kinds of aluminum pcb for led tube, which varies based on the length and width of led tube. Aluminum pcb for led tube is popular with people due to its good quality, and durable and energy-saving features.

led strip
led strip

Aluminum pcb for led tube can save electricity as high as 70%. The light intensity of 12W Led tube is equal to 40w fluorescent tube. The service life of LED tube is is more than 10 times that of general fluorescent tube. It can be free of maintenance. Also, there is no need to change LED tube, barratter and starter frequently.

Generally, fluorescent tube has high temperature inside and needs to be used for more than 10 hours everyday in most cases. This problems are perfectly resolved by aluminum pcb for led tube.

If you have any queries, comments or suggestions on aluminum pcb for led, welcome to leave your message.

The Production Process of MCPCB Multilayer

Tuesday, March 10th, 2020
  1. Pretreatment-the 1st production process of mcpcb multilayer

Confirm the processing method of the hole: Drilling and punching are used to process the holes of mcpcb multilayer. The feed degree and rotating speed of drilling is different from FR-4 PCB material. Adjustment needs to be made according to base material. Generally, we set the feed degree at 1-1.5 mil/rev, and the rotating speed at 20000-60000RPM. Punching requires specialized tooling to meet the needs of metal punching.

mcpcb multilayer
mcpcb multilayer

Drilling of the inner layer core board should be carried out, according to the drilling parameters of FR-4 PCB. There should be enough vacuum degree and pressure foot, for keeping holes clean and removing debris. The number of drilling holes and wear condition should be well controlled.

During the process, we use dry film(1.3-2.5 mil water solubility light induced corrosion resistant dry film), and wet film(wet film light induced corrosion resistant solvent).

  • Circuits Electro-Plating/Etching-the 4th production process of mcpcb multilayer

Circuits Electro-Plating: Acid copper plating and tin plating are suitable for double-sided core board.

Etching: During etching process, we need to adjust speed according to the thickness of copper foil. In order that core board can be etched smoothly, we can reduce pressure of etching spraying, or make towing plate.

Then complete mechanical and electrical performance of mcpcb multilayer can be established.

  • Drilling/Punching and 2nd Drilling-the 6th production process of mcpcb multilayer
mcpcb multilayer
mcpcb multilayer

After lamination, when epoxy resin is completely cured, and epoxy resin of board is removed, 2nd drilling should be carried out. This operation involves mechanical processing of metal-base composite material. This is a challenge to structure of mcpcb multillayer. Special attention should be paid during operation, especially location precision and quality of processing holes.

There are 4 ways for making soldermask: liquid light induced corrosion resistant solvent; Thermosetting soldermask;UV curing soldermask; Dry film soldermask.

In order to facilitate assembly of components, exposed copper foil surface must be treated, for enough solderability, good bonding power and comprehensive manufacturing performance. There are 4 ways for surface finishing: HASL, OSP, Sn and Ni/Au.

Packaging of mcpcb multilayer is important for reducing abrasion mark and wear. Using low-sulfur sheet for vacuum sealing is a good choice. Foam can also be used separately. The key is to isolate soldering flux from aluminum surface, in this way, we can eliminate galvanic electricity reaction between different metals.

Special Women’s Day Gift for Lady in Best Technology

Saturday, March 7th, 2020

Tomorrow March 8th, 2020 will be the Women’s Day! As it’ll be Sunday, so everyone in Best Technology get the gift today: One box of facial mask, one bottle of eye cream, and one bottle of moisturizer


We hope every lady in Best Technology keep happy, beautiful, while they’re working so hard, even working in middle night, in order to give our customers immediate reply. This is one of reason why you can see email reply within one hour sometimes even in the evening!


It’s the first time that every girl in Best Technology take a photo with a face mask! Everyone in Best Technology want the Coronavirus to be finished ASAP, so that everyone doesn’t need to have a face mask and global economic turn back to normal level. At that time, we can take a photo again so that you can see the smiling face of our girls😊 and we believe that day will come in soon!

If you want to ask some information about our product (FR4 PCB, metal core PCB, ceramic PCB, PCBA) or service, you’re welcome to send email or call us anytime!