In September, 2018, in order to provide customers with the most suitable products and the most satisfactory services, Best Technology released a new product—-2L FPC Coil Board with Bumped Point. This product was developed on the basis of the old version. The surface of the old one is flat. For this reason, it will cause poor contact when assemble with a conductive film.
Could you tell the difference between the old one and the new one? If not, hoping this article can solve your puzzle.
Picture1: New Version VS Old Version
There is an obvious difference—-the new version has bumped point, but the old one is opposite. So what is the advantage of 2L FPC Coil Board with Bumped Point? The new one with bumped point, it will get easier to connect when assemble with a conductive film. Because the shortcoming of the old one, we have improved with advanced technology, adding bumped points in the flex printed board. And it is easier to connect when the pad is attached with the conductive film.
From the following picture, we can see that the new version is single-sided flexible circuit board with bumped point.
In 2017, All the guys in Best Technology have many good and warm memories. Everyone has worked hard, and was busy for US$500 sales target in the past year 2017. Finally, we finished the sales goal successfully. On Jan 28th, 2018, Best Technology hosted a wonderful evening party to celebrate the new year. We will keep going and do the best partner of flexible printed circuit board in Asia.
Everyone has worked hard
At 5 PM, We started the night party. Under the host of two beautiful ladies, Miss Connie and Miss Luo, we have a wonderful and joyful starting.
two beautiful ladies
Then the game time, it’s fantasizing. Win the games, and then you can got the gifts. Hands up quickly, and be smart during the game. You can win the prizes easily. Best Technology have prepared many different kinds of gifts.
After the games, we sang together. Mr Gui also played a magic, and everyone thought it’s funny and laugh loudly.
Little prince was singing a song father
Picture: Little prince was singing a song <father>
Took a family picture, very nice, seems everyone had a good time.
With the development of modern industry, there are more and more projects need to use flexible circuit, and the requirements of assembly are getting higher and higher.
In the Flex Printed Circuit(FPC) typical production process, normally we will finish the entire flexible PCB production process, and then arrange to solder components. But such a finished product, components exposed, it can not pass the waterproof test. Our traditional waterproof process is to cover Silicon or conformal coating.
Our engineers decided to change the production process after discussion. For new technology,
The first step is trace Etching;
Second step is surface treatment (normally is ENIG (Electroless Nickel/Immersion Gold);
Third step is component assembling;
flex circuit with component stackup
The Forth step and the most important step is making the pure adhesive between base material and coverlay, we need to laser cutting or punching the cutout above the area of component, so that there’s no extra adhesive in that area and then the total thickness of that area will no be too high.
flex circuit with component stackup2
And you can see the full picture showing step 3 to step 4 of flex circuit components making.
flex circuit with component stackup
After that, we put the Polyimide on pure adhesive and then go the next step of lamination process. (To laminate the coverlay on the surface of component.).
You can see below pictures.
flex circuit with components
flex circuit with components details
You can visit our website or send us your email if you would like to know more about flex printed circuit.
How to deal with these situation?There have glue mark and greasy dirt on the boards in prepared processing stage, it need to clean the plate thoroughly.
The temperature is too high and time is too long in the stage of Pre-heating, so it need to control the temperature of the pre-drier, adjust it on normal temperature and strengthen the control of time.
The exposure energy is too high on the stage of exposure, or the shading rate is poor of the base boards.
The developing liquid’s concentration and the temperature are too low, so it need to check the concentration and adjust the temperature to normal timing.
Differences between Roll Anneal Copper Foil and Electrolysis Deposition Copper Foil
Roll Anneal Copper Foil (RA copper):
Formation: Roll copper block many times, and then do the annealing treatment with high temperature. The shape of its crystal is lamellar structure.
Advantage: Soft, smooth surface, suitable for flexible PCB and small lines.
Shortage: high cost
Electrolysis Deposition Copper Foil (ED copper):
Formation: Melt copper into dilute sulfuric acid, it becomes bluestone solution.
Through a high electric field, copper attach on the metal drum. With the rolling of metal drum, thin copper foil finally formed.
Advantage: Low cost
Shortage: Unsuitable for small lines; bad bending resistance.
Here is the cross section observation of RA Copper and ED Copper:
As you can see, there’re adhesive in base for each four basic thickness of 2L (double sided) flex circuits, if you need more thin, then you can use adhesiveless material, and final thickness will be thinner even you use the same copper and Polyimide thickness. Please see next article (to be continued…)
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.