Flexible PCB -Flexible Printed Circuits are made of thin dielectric substrate & high ductility metal foil, flexible pcb can be bent or folded and used in static and dynamic applications.
Do you know why the fpc need to add the stiffener?
Flexible-only PCBs can withstand fewer components than rigid-flex. The rigid part of rigid-flex can also be as complex as a traditional rigid Circuit Board. Stiffeners are occasionally laminated the same time as the coverlay.
When we need to add the Stiffeners ?
Components are near or in an active, or dynamic, flex zone Component size and weight will import stress onto the flex A large number of SMT pads make planarity critical Connectors that require repeated insertions or assemblies require a stiffener, or something to help alleviate the stress of pads.
When we donāt suggest to to add the Stiffeners ?
Ā Small āstaticā components do not exert a large amount of strain on the flexible of the PCB.There are no components in the flex region. Ā
How to choose the FPC stiffener? As we all know, the Stiffeners are typically made of FR4, PI(Kapton), stainless and alumimum stiffener.Then how we we too choose the right stiffener?
PI is often used when the end of the flex must be thickened and inserted into a ZIF connector. However, the use of Kapton(PI) requires a separate lamination cycle. For golden area, we will be need to add the PI stiffener to meet the total thickness 0.2mm, 0.3mm or 0.5mm.
PI stiffener
FR4 stiffenerĀ can be done within the same lamination cycle.Ā FR4 stiffener usually added for the USB connector area.
FR4 stiffener1
Stainless stiffenerĀ is not easy to transformation. And it has the good hardness. And it can play a conductive and inductive role.
Stainless stiffener
Aluminum stiffener has the best heat disspation effect, because it usually need to openning a tooling to cut the alumunum stiffener outline, then the cost is the highest.
Alumininum stiffener
Are you got it? If you have any comments, please kindly feel free to let me know. Please contact Best Technology at sales@bestfpc.com.
Covering is the film that covers and presses on the surface of the flexible circuit, usually polyimide resin, used for solder mask, etc., and has little effect on signal shielding. The Electro-Magnetic Interference (EMI) shield is generally attached to the coverlay, and the price of the EMI shield is much more expensive than the coverlay. What is the difference between FPC coverlay and EMI shield?
FPC coverlay, known as CVL in the industry, it has the same main function as the solder mask of PCB: 1) Protect the copper foil from being exposed to the air and avoid oxidation of the copper foil; 2) Cover for the areas which it do not need to do surface treatment. 3) The solder resist function in the SMT. The usual colors are yellow, black and white in Best Tech.
The EMI shield uses mixed composite metal as the shielding material and has excellent OSP performance and corrosion solvent resistance. It is superior to similar products in the market in shielding and winding characteristics. The EMI shield is suitable for flexible printed circuits. It has high shielding, bending and heat resistance. The usual color is black in Best Technology.
EMI material
After pressing the cpverlay, the FPC will press a layer of EMI shield as a conductive layer to shield the external electromagnetic interference. EMI shield is mainly used in 3C products such as notebook computers, GPS, ADSL and mobile phones, because they all produce noise due to high-frequency electromagnetic interference, which affects the quality of communication.
Before we point to the topic, Iād like to share one story with you first.
Recently, one of our customers, whose projects need ENIG(1uā) on whole surface, and we didnāt know these projects was strict with the gold surface on some special area.
There are two pre-treatment for ENIG, one is gridding plating, another is sand blasting. At first, what we used is gridding plate, so when customer watched the gold surface can saw some cracks.
Gridding plate
To solve this issue, we suggested to try sand blasting ENIG pre-treatment. Compared with gridding plating, it only need slightly brush the plate. But itās still cannot meet customerās need.
Sand blasting
For normal design, change the surface treatment from ENIG(1uā) to gold plating can completely solve this issue. But in this design, the PADs on boards are separate, and there are in different gridding with outside. So gold plating is infeasible for this design.
Only when the inner PADs lie in same gridding with big copper plate, the gold plating is feasible.
So, let going to todayās the topic. Whatās the difference between ENIG and plating gold?
The difference in process.
ENIG is called immersion gold, achieved by chemical deposit. Through an oxidation-reduction chemical reaction, it formed a layer of coating. Itās one of chemical nickel-gold depositing methods, can reach thicker gold layer.
It need pre-treatment gridding plating and sand blasting before immersion gold, need brush the board to enhance the adhesion between the board and the gold surface.
2ļ¼Gold plating use the principle of electrolysis, also known as electroplating. Neednāt pre-treatment before plating gold.
The difference in color.
ENIG is golden.
Plating gold will be slightly whiter (nickel color).
The difference in performance.
The crystal structure between ENIG and gold plating is different. Compared with plating gold, ENIG is easier to weld and will not cause bad welding.
The stress of ENIG is more easily controlled, for the products with bond, more conducive to the processing of the bond.
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Last but not least, as we mentioned at the beginning, if your project need plating gold, pls make sure these area need gold plating can connect with outside gridding.
Hope above information is helpful for you to know more about ENIG and plating gold.
Flexibility is the most obvious advantage for flex PCB, but we should maintain a degree during use, not just bend casually, so what should we pay attention to when bending?
BESTFPC1
bestfpc2
Although the FPC can be bent, if it is bent at 180Ā°, this may cause damage to the copper traces, and it lead to open or short circuits.
Most of the ink-type protective layer is not resistant to bend, such as text/silk screen, marking, solder mask, etc. It is strictly prohibited to have more than 90Ā° bending action in the assembly process.
The corners of the FPC outline, which are prone to tearing during the assembly process, reminding users to pay attention to it.
The exposed part of the FPC is subjected to surface plating treatment, such as gold/gold plating, etc., the focus is on preventing oxidation. This area is not suitable for bending.
Although there is a stiffener design in the golden finger plug-in area, it is still not suitable for bending in this area. Special attention should be paid to the assembly process.
Do not bend directly on the via area of FPC.
If you have any design question about bending area, please feel free to contact us at sales@bestfpc.com. We will share more details about increasing the bending times soon.
We received a special project, one of our customer need 2L FPC, and want the thickness between two copper layers to be 0.15mm. Because this customer is specialized in RF product, he need so thick dielectric(0.15mm) between two copper layers.
Firstly, for adhesive material, it means āadhesive + Polyimide + adhesiveā should meet 0.15mm. If Adhesive is 25um, two adhesive layer totally 50um, the minimum Polyimide thickness will be 4mil.
Secondly, for 4mil Polyimide, it usually refers to adhesive-less material. So if deduct 50um adhesive, it require 6mil adhesiveless material. 6mil adhesiveless PI is very hard to purchase, need to customize, have MOQ limit, and lead time will be very long.
Is there any solution to meet customerās need?
After discussed with our engineers and manufacture department, we put forward one suggestion. Draw an stack up with 6L FPC, itās made up of three double-sided FPC. Etch out one copper layers in TOP and Bottom double-sided FPC. And for the middle double-sided FPC, weāll etch out two copper layers, only leave Polyimide and adhesive.Ā
By doing this, it finally will only leave two copper layers, and the thickness between two copper layers is 0.15mm. (As below stack up show)
To be honest, when customer put forward to his design requirement, I was amazed, 0.15mm material is so hard to purchase. But our engineers and manufacture department find a good solution for our customer. Our customer are satisfied with our work.
As we all known, some customer need to do following assembly in their side when received the bare boards. In order to facilitate customers for subsequent assembly, weāll ship out boards in panels. So, whatās the difference between FPC and PCB paneling connection mode?
For FPC , we often use connecting tabs to connect the boards.
FPC connecting tabs
For Rigid PCB, we often use V-cut and connecting tabs(with stamp holes) to connect the boards.
PCB V-cut
For Rigid-flex PCB, weāll use connecting tabs(without stamp holes) in flex part, and use connecting tabs(with stamp holes) in Rigid part.
connecting tabs(with and without stamp holes)
Take the Rigid-flex PCB for example, if the boards are easy to fallen from panels when do assemble, how to improve the design?
Best Technology, a China- based assembly manufacturer will be exhibiting at electronica MunichĀ 2020 in Bavaria, Germany at booth No. 623(Hall B1) from November 10, 2020 to November 13, 2020(Western Time). Actually, we have participated in this exhibition for continuous 2 years. Here are some pictures for your reference.
pcb exhibition
pcb exhibition
pcb exhibition
pcb exhibition
At our exhibition booth, attendees will be able to learn more about our company for PCB manufacturingĀ and PCB assemblyĀ technology.
For interested professionals, Best Technology had on hand experts to offer detailed insights and experience on PCB assembly, covering PCB prototype and low/high-volume production. For more information on PCB assembly and fabrication, welcome to visit our booth.
You are warmly welcome to see how we can manage the components wastage and efficiency to help save your time, money and energy.
About electronica Munich:
Electronica is the international trade show for electronic components, systems and applications and shows the full range in all its diversity in width and depth as the world’s leading trade fair. It reflects the high degree of innovation throughout the industry. Exhibitors and users in the areas of systems, applications and technologies of electronics can receive the information of the latest innovations and developments in the fields of system peripherals, power engineering to printed circuit boards or EMS.
Welcome to visitĀ us at Booth 623 from November 10, 2020 to November 13, 2020(Western Time).
Regarding HS code and duty rate of face masks in some major countries, we collected some information in main trade partners (US, Japan, EU, Korea, Taiwan, Australia, New Zealand) of China. This is aimed at the face masks such as personal protective masks without special function components, including medical face masks and disposable face masks. All of below information were published by the custom officially.
According to Harmonized Tariff Schedule of the United States, HTSUS, the HS code of face masks in the US is 6307909889. And the duty rate imported from China is 7%. Regarding tariff imposed, according to announcement from the United States Trade Representative on March 12, 2020, the tariff is excluded for the face masks belonging to this HS code since September 1, 2019. Since then, all the face masks imported from China has been exempted from tariff. You can refer to the below chart for more information.
face mask tariff
Japan:
The HS code of face masks in Japan is 630790029. The duty rate imported from China is 4.7%. To learn more, see below:
face mask tariff
EU:
The duty paragraph for face masks imported from China in EU is 6307909899 and the duty rate is 6.3%. You can see below for more information:
face mask tariff
Korea:
The duty paragraph for face masks imported from China in Korea is 6307909000, and normally, the tariff is 10%. However, from March 18, 2020 to June 30, 2020, Korea has been suspending imposing tariff for face masks from China(0 tariff currently), see below for more information:
face mask tariff
Taiwan, China:
The HS code(also referred to as duty paragraph) of face masks imported from China mainland in Taiwan is 63079050.
And, the duty rate for face masks imported from China mainland is 7.5%. However, from February 27, 2020 to May 26, 2020, provisional tax rates (also referred to asāflexible tax rateāin Taiwan area) for face masks was carried out in Taiwan area, i.e. the tariff is zero. You can see below for more information:
face mask tariff
Australia:
The HS code of face masks imported from China in Australia is 63079099 and the duty rate is 5%. See below for more information:
face mask tariff
New Zealand:
The HS code of face masks imported from China in New Zealand is 63079028. Zero tariff is applied to the face masks imported from China according to āNew free trade agreementā. See below for more information:
Global demand for supplies used by our customers to treat and help protect people, such as respirators, is currently exceeding supply. Best Technology expects demand for respirators to outpace supply for the foreseeable future.
disposable face mask
Throughout all the recent developments, Best Technology is working hard to uphold the commitments we made to supporting your business. We are very focused on protecting the health and safety of our workforce while maintaining the ability to keep serving you.
With more than 10 years of domain expertise in the industries we serve, we are here to help you adjust to whatever may happen next.
The COVID-19 pandemic continues to affect all of us, and all Best Technology colleagues are working around-the-clock to help provide critical tools for the fight. Our current focus: supporting health care and front-line workers as well as our regular and new customers around the world by providing products they need to help protect their lives.
We are seriously in choosing partners who can provide various kinds of respirators as well as medical products:
The partners who can double their global output rate to nearly 100 million respirators per month are in our priority;
Also, we anticipate doubling global capacity of our partners to almost 2 billion respirators in the next 12 months.
We have not increased the prices we charge for our respirators in this crisis.
KN95 mask
Our efforts are guided by our value of Caring ā for our people and their families, our consumers, and importantly, for those most in need right now. We want to share a few of the ways that we are responding to this global health crisis.
Moreover, after our efforts, all of our face masks, KN95 masks and all of other medical products have passed GB2626-2006 and CE standard. You can also find out the certificates from the above website.
Anything I can do for you? If there is a need, contact us anytime. Our sales team will be here to reply you instantly. Please keep safe and take good care of yourself and your families. Come on, our friends, wish the pandemic will end asap and everything can return to normal soon.
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
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.
During the height of the outbreak, trains didn’t stop at the disease’s epicenter, Wuhan
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 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
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
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
In China, elective surgeries and other non-critical doctorsā 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
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
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
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
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
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
volunteers
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
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.
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