Solderability Test Experiment

As is well known, solderability is very important for the printed circuit boards, we must do solderability test of each batch PCB we made. In this way we can inspect the weldability of the PCB before we go ahead the assembly process, much helpful for SMT.

Today we are going to discuss the solderability test experiment. In order to explain it more clear, we now do a simple solderability test and show you all the steps.

1. Take a small solder pot, plug in the power, turn on the switch and heat the solder pot to a certain high temperature(about 8 minutes).

2. Put a tin bar to the solder pot, then you can see the tin bar is begin to melting, slowly into liquid tin, then more and more.
3. After few minutes, there will be enough melting liquid tin in the solder pot to do this test.
4.Use a tweezers to pick up a PCB circuit, first clean the PCB with rubbing alcohol. Because the unclear surface or the oxidation of the PCB will affect the test result.
5. This is the key step of this test, put the PCB into the solder pot, depth about 2 mm,time 4-5 seconds is ok. Then you can see the tin will go into the hole of the PCB.
6. Take out the PCB from the solder pot and put it into the cold water. After few seconds, you can see the experimental effect.

This solderability test is very simple and easy. We can see the results very soon. Our Best Technology did solderability of every batch PCB we made, and we also supply our customers with the solderability test report and the test samples.

Happy National Days

With the weather is getting cold , now we really greeted the Autumn, a season of harvest and happy. In this enjoyable autumn., we also willl usher in the most important festival in China- National Day.

The National Day of the China is celebrated every year on October 1. It is a public holiday in China. Usually people will have a 7 days holiday to celebrate the national day, called “Golden Week”.

National Days are festivals which can stand for independent countries. In the world, countries establish their Notional days on the basis of different ways. Therefore, the names and celebrations of National days in different countries are various. In China, The most significative activity in National Day is The Big Parade in Beijing, Parade Is a ceremony to review the armed forces.

This day is a day of national celebration. Most people will go travel on this holiday, especially to visit the “Red” tourist sites. People also can enjoy kinds of evening party.

On this national day of prayer and remembrance, we ask almighty God to watch over our nation, and grant us patience and happyness!

Our Best Technology will have a 4 days holiday from tomorrow (Oct 1) to Oct 4 to celebrate the National Day, and reopen on Oct 5. Hope everyone can enjoy this holiday and have a good rest.

Happy National Day! Best Wishes To Our Great Motherland May our country become prosperous and strong!

Happy Mid-autumn Day!

Time flies! Now we ushered in the 2011 Mid-Autumn festival.

Mid-autumn Day is one of the import traditional Chinese festivals, falls on the fifteenth day of the eighth lunar month. On that night the moon is brighter and fuller than any other night. In China, Mid-autumn Day is a time for family reunions.

In ancient China, poets considered the moon as a symbol of brightness, purity, and goodness. They wrote many beautiful poems about the moon. The most popular one was a story about a lady on the moon. She flew to the moon and lived in the Moon Palace.

On Mid-autumn Day, almost everyone gets together with his or her family, eating mooncakes, chatting and watching the moon. Mooncake, whose round shape symbolizes both the fullness of the moon and family togetherness. There are many kinds of mooncakes. They are small round cakes with meat, nuts or something sweet inside . eating mooncakes has been our custom.

The Moon Festivals is one of three major Chinese holidays, along with the Spring and Dragon Boat Festival .On that day, families get together,so we call this day getting together. This is Mid-autumn Day. I love it very much.

Our Best Technology we will have a three day holiday(from Sep 10 to Sep 12) to celebrate the Mid-autumn Day and will reopen on Sep 13. Best Technology wish you all have a happy Mid-Autumn festival! Enjoy the beautiful life together with your family forever.

Tomb-sweeping Day

Tomb Sweeping Day is one of the few traditional Chinese holidays that follows the solar calendar– typically falling on April 4, 5, or 6. Its Chinese name is “Qing Ming” literally means “Clear Brightness,” hinting at its importance as a celebration of Spring. Similar to the spring festivals of other cultures, Tomb Sweeping Day celebrates the rebirth of nature, while marking the beginning of the planting season and other outdoor activities.

The Tomb Sweeping Day in Ancient Times
In ancient times, people celebrated Qing Ming Jie with dancing, singing, picnics, and kite flying. Colored boiled eggs would be broken to symbolize the opening of life. In the capital, the Emperor would plant trees on the palace grounds to celebrate the renewing nature of spring. In the villages, young men and women would court each other.

The Tomb Sweeping Day as Celebrated Today With the passing of time, this celebration became a day to honor the past ancestors. Following folk religion, the Chinese people believed that the spirits of deceased ancestors looked after their family, sacrifices of food and “paper money” could keep them happy, then they would bless the family prosper through good harvests and have more children.
Today, Chinese visit their family graves to tend to any underbrush that has grown, remove the weeds, swept away the dirt, and set out offerings of foods and burning “paper money”.

Up to now, the custom of obeisance ancestry and grieve over those already died relatives on Tomb Sweeping Day are still very widely accepted.

Out Best Technology will have our Tomb Sweeping day holiday from today till Apr 5. And back on Apr 6. Hope everybody have a nice weekend and enjoy life better.

Solderability Test

Solderability testing has become more common in the industry particularly to assess components and printed board surface finishes during the transition to lead-free manufacture. The wetting balance is the standard method of test and provides the repeatability that other methods do not.

Test Principle: Put the samples into tin bath, detect the solderability according to the hole wetting degree.
Ttest Purpose: Test the solderability of the PCB samples
Test Instrument: Thermostatic tin stove

Procedure:
1. Setting the tin slot temperature at 245℃, turn on the power.
2.Waiting for the Test Procedure up to 245℃+/-5℃, paint the samples with rosin. Use clamps nip it , just do as wave-soldering,let samples contact with the tin slot surface. Depth is about 2mm, time is nearly 4 seconds.
3. Tin material changing times: once / two weeks
4.Comments: The plated holes permit only 10% with half infiltrating, nonwettable and air blow is not allowed.


Figure 1. PCB samples before testing with the wetting balance



Figure 2. PCB samples after testing with the wetting balance.

As assembly Electronic components to printed circuit board always need high quality Interchange connection technology, doing the solderability test has great help to the high quality and zero defects welding technology. Our Best Technology did Solderability Test for every batch PCB, but due to some objective reasons, we didn’t give customers the solderability test samples. If customers need it, can also contact us.

The PCB raw material rise in price

International copper prices surged in the latter part of last year,this directly impact the price of copper foil. Since last September it raised month by month. It is reported that February is still raising 8% to 10%, and don’t eliminate to reset to higher prices again in March.

The substantial price rise of the copper foil directly influences the CCL and PCB industry. In February, both the thick and thin CCL had raised 5%-8%. Fiberglass had risen 20%. The PCB industry have gradually turned the corner also had to rise in price. The PCB industry improved obviously in the first quarter this year since last year’s downturn. The price of fiberglass appears a rose space .

On the side, the RMB appreciate against USD dollar, furthermore, gold and copper price, still keep rising since late last year. Especially CCL have also rised this year, this made PCB manufacturers under much pressure, more than 10% of the products had been raised the prices. Some few manufacturers are still keep communicating with their customers recently.

Merry Christmas


Christmas Day is a holiday observed generally on December 25 to commemorate the birth of Jesus, the central figure of Christianity. It’s a national holiday in western countries resemble the Chinese New Year. But now, it has grown steadily over the past few centuries in many regions of the world.

Christmas means a joyful time of year. It brings friends and family together. Everyone smells joy in the air and everyone is celebrating Jesus’ birthday. It’s a matter of opening gifts, you can get a lot of presents from “Santa Claus”.

Christmas Day is the time spending with your family, seeing all the beautiful lights, decorating the tree, eating all the food you can eat, send gifts to each other. How Happy!

The Christmas atmosphere in China is getting more and more strong these years. Many family and supermarkets also have a decorated Christmas tree. People sent gifts and cards to show their blessings . All Peole are doing expect for the new year .

Christmas to me means when you think of people that love you and the people who are loved by you, not just all the presents and the decorations. It’s all about giving and recieving and spending time with your loved ones.

With the Christmas Day approaching, Best Technology take this opportunity to celebrate a fruitful results in 2010 and wish good luck and success in 2011 .

Warm greetings and best wishes for Christmas and the New Year!
Wishing everybody peace, joy and happiness through Christmas and the coming year.

The knowledge of printed circuit board via

                                     via

                                  The basic definition of via

As is known to all, via is one of the important parts of multilayer PCB. The cost of drilling usually makes up 30%~40% of the cost of PCB manufacture.

Simply speaking, every hole on PCB may be called via.

Functionally, via can be divided into two types: firstly, used for electro-connection among layers; secondly, used for fixing components.

Technically, it may also be divided into three types: blind via, buried via and though hole. Blind via is located on the top and bottom surfaces of the PCB, deep and used for connection of top traces with the inner layer traces below.

Buried via is the connecting hole which is located in the inner layer of the PCB and won’t extent to the surface.

Through hole goes through the whole PCB, which is used to realize inter-connection or used as components mounting position hole. Due to the simple technique and low cost, most of PCBs use it rather than the other two via.

The basic knowledge of PCB(3)

Today we will continue expanding some basic knowledge of PCB:

3. Components encapsulation technology

(1) Through hole technology

It means we mount components on one side, and solder the pins on the other. The disadvantage of it is space consuming. In fact, theirs pins take up space of both sides. While the advantage of it is good construction, which can bear pressure.

(2) Surface mounted technology
it means pins are soldered on the same side as components. We don’t have to drill holes  on PCB and don’t have to solder every pin. The advantage of SMT is that the components are more compact and cheaper than those in THT.

                                                smt2 

4. Gerber files:

Usually it comprises the layout plan of signal, ground, power, solder mask, silk screen, and drilling layout plan, etc.

                                          gerber file

5. Manufacture steps
choose base material, then use subtractive transfer to show the artwork on metal conductor.

The above explanation is only the most basic   information, if you want to know more, please to go our website: http://bestpcbs.com/products or contact me at Iris@bestfpc.com.

We are happy to help you clear all your questions!!!

The basic knowledge of PCB (2)

2. The classification of PCB

 (1) Single sided PCB

Single sided board means the conductor pattern appears only on one side. Because single sided PCB has many strict limits. On trace design, only circuit at early stage use this kind of boards.

(2) Double sided PCB 

Double sided board means the conductor patterns appear on both sides of the board. However if we use the conductor patterns on both sides, there should be proper circuit to connect two sides. The bridge between the circuits is called via. Those vias are plated with metal, such as tin, copper, gold, etc. Because the area of double sided PCB is two fold of the area of single sided, and the conductor pattern can cross with each other, so it suits to be used on more complex circuits.

(3) Multi-layer boards

In order to enlarge the area of conductor pattern, multilayer PCB uses more single or double boards. It uses several piece of double sided boards, and a dielectric layer is put between every layer of boards. The layers of one PCB represent the layer of conductor patterns. The amount of the layers is always even number. Technically we can make PCBs up to 100 layers.

 For via, if we use it on double sided PCB, the whole boards will be drilled. While on multilayer PCB, if you just want to connect some traces, via may will waste trace space of some layers. Then we use buried vias and blind vias to solve this problem, because they are only drilled through several layers.

a. Buried vias only connect inner PCBs, so we can’t see them from the surface.

b. Blind vias connects several layers PCB with surface PCB.

In multilayer PCB, the whole board directly connects the ground line and power (used for preventing affection of the transmission signals on the signal). So we divide layers into signal, power, or ground. If the components on PCB need different power supply, this kind of PCB would have more than two layers of power and wire layers.

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