Archive for the ‘PCBA’ Category

The SMT production progressing

Thursday, November 18th, 2021

SMT (Surface Mounted Technology) is the most popular Technology and process in electronic assembly industry. SMT refers to a series of process processes based on PCB. Due to the better outcome and higher efficiency, SMT has become the primary approach used in the process of PCB assembly. In some extent, the turn-key service is a way to reduce the cost.

There are the SMT progressing in the following.

1. Solder paste printing: The function is to print the solder paste to the PCB pad to prepare for the welding of components. The screen-printing machine is located at the front end of SMT production line.

(Automatic solder paste printer)

2. Part mounting: The function is to accurately install surface assembly components into fixed positions on the PCB. The equipment is the SMT machine, located behind the screen-printing machine in the SMT production line.

3. Furnace curing: its function is to melt the patch adhesive, so that the surface assembly components and PCB board firmly stick together. The equipment used is the curing furnace, located behind the SMT machine in the SMT line.

4. Reflow welding: The function is to melt the solder paste, so that the surface assembly components and PCB board firmly stick together. The reflow furnace is located behind the SMT machine in the SMT line.

(Reflow soldering)

5. AOI optical detection: its function is to detect the welding quality and assembly quality of assembled PCB board. The equipment used is automatic optical detection (AOI)

(AIO machine)

6. Maintenance: its function is to detect the failure of the PCB board for repair. The tools used are soldering iron, repair workstation and so on. Configured after AOI optical detection.

7.Dividing board: its function is to cut PCBA of multiple connecting boards, so that they are separated to form a single individual, generally using V-cut and machine cutting.

8. Grinding plate: its role is to scrub the burr parts to make them smooth and flat.

9. Washing plate: its function is to remove welding residues such as flux and other harmful to human body on assembled PCB board and manually clean it.

Turnkey service reduces customers’ time in contacting with multiple suppliers for separate steps in PCB assembly manufacturing. And the scientific order arrangement system allows customers to get PCB assembly products with higher quality and less cost in a shorter time than the traditional way of PCB assembly.

(SMT production line)

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Notes for cleaning PCBA

Monday, October 18th, 2021

PCBA includes components assembly and DIP plug-in, in the whole process, there will be reflow soldering, wave soldering, manual soldering, due to the current Electronic products are getting smaller and smaller, and the size requirements of PCBA are getting smaller and smaller, but the requirements for quality (including product reliability and stability, etc.) are getting higher and higher. Many customers require PCBA boards with conformal coating to increase stability and reliability and ensure product quality and performance. But the PCBA board must be cleaned before with conformal coating.

Because there will be a variety of flux residues on the soldered MCPCB board, some of which are acidic, soluble and corrosive, etc., if these residues are not cleaned, the coating will also cause very great damage to the product. In this blog I’d like to share some notes for cleaning PCBA.

  1. PCBA board after soldering, should be cleaned as soon as possible (flux residue will produce corrosion over time), cleaning residual flux and other pollutants on PCBA board.
Copper Core PCB
  • When cleaning the PCBA board, prevent the cleaning agent from intruding into the unsealed components to avoid damage to the components. After cleaning, it should be placed in the oven at about 30-50 degrees, baked for about half an hour, and then removed after drying PCBA board.
FR4 PCB
  • When cleaning the PCBA board, protect the components and labels on the board. Otherwise, the mounted and welded PCBA board will be wasted.
Aluminum Core PCB

Cleaning PCBA board affects the life and reliability of electronic products. Some of PCBA boards are not cleaned, which may lead to short circuit and leakage, leading to unqualified products and many failures, increasing the cost of recovery and maintenance, so it is not worth the loss to clean PCBA boards.
 

Best Technology has own SMT factory and can help our customers to buy the components at the same time. If you have any new inquiry of PCBA, welcome to send it to me then I can send you the quotation for comparison with your other suppliers.

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What’s fiducial marks on the PCB?

Saturday, April 24th, 2021

You may ever be recommended by some PCB manufacturers to add the fiducial holes on the board edge. Do you know what is fiducial marks and what’s the purpose for this kind of holes in a PCB?

Now, let me to show you something for what is the fiducial holes.

Fiducial holes, we also call it fiducials mark, while we assemble a PCB, it will need to locate the positions for each component, and it is positioned based on the fiducial mark as the reference point.

There are 3 types fiducial marks, first type is fiducial marks on a single board, second type is the fiducial marks on a PCB panel, third one is the fiducial marks for some single component on the board.

Here are the pictures for you to understand the types of the fiducials.

Fiducial holes types
Fiducial holes

Fiducial mark on a single board is designed for positioned all circuits features on a single board. It is necessary to have a fiducial mark on a single board.

And fiducial marks on a PCB panel is used to assist positioning the circuits. 

For the fiducial mark of a single component, it is designed to position the fiducial mark of a single component, which can improve the placement progress (For QFP, CSP, BGA and other important components must have the fiducial marks).

So, it is important to add the fiducial holes on a PCB board.

Also, while we make the panel for the PCB board, on the diagonal of the four corners, it is required to have 2 fiducial points at least on 2 diagonal corners.  you can also place 4 marks on the four corners, but generally, assembly plant will only need 2 marks for recognize.

See below a PCB panel for reference:

PCB panel drawing Best Technology
Fiducial holes on a panel

In the other hand, while you design the PCB, please try not to put the silk screens, pads, traces etc. within 2mm of the optical fiducial marks. Otherwise, the SMT machine will not be able to recognize the optical fiducial on the PCB boards.

And if you add the fiducial holes on the area which without any circuits, to avoid the holes being etching while the process, so generally we suggest to add a metal circles around the fiducial holes, to make it more obviously on the boards.

If you have any new PCB design which you also want to add the fiducial marks.

You are welcome to contact Best Technology for a help and we will show our best help for you.  

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The Advantages of Surface Mount Technology of a printed circuit board

Friday, March 19th, 2021

Surface-Mount Technology has been the industry standard for assembling printed circuit board. It has maintained its popular due its wide array of advantages and relatively few drawbacks. For more than 15 years’ experience, Best Technology has been offering surface-mount service for worldwide customers, and SMT service become a great part of our business.

See some photo which we are do assembly for our customer this month.

SMT 1

Top Advantages of Surface-Mount Technology

Smaller size and reduced weight are the two main advantages to SMT. Components can be aligned closer together and end products will be more compact and light weight.

SMT 2

Here are additional benefits of SMT:

1.Component placement auto correctly â€“ there is no alignment between the PCB solder pads and components pads to avoid placement errors.

2.Low cost:

The advantage of small size up to 0201. One set, SMT typically requires lower production costs than through-hole placement. The size of the board is reduced, the number of drilled holes is reduced, and routing of traces is reduced. So bring down the cost of the whole project.

3.Design flexibility â€“ You can combine through-hole technology and SMT manufacturing on the same board for greater functionality.

4. Printed circuit boards created with the SMT process are more compact, providing higher circuit speeds. (This is the main reasons most manufacturers choose for this method.)

5.Higher circuit speeds â€“ Most manufacturers rate this the number-one benefit.

Lower resistance/induction â€“ High-frequency performance reduces unwanted consequences of RF signals.

6. Quick Turn Around

Using Surface-Mount Technology, it can save lots of time, SMT is a much more streamlined manufacturing process compared to through-hole. Time is saved because components are applied using a solder paste instead of drilling holes in the PCB

7. Quantity â€“ More components can be positioned using both sides of the circuit board, creating more connections for each component. Fewer circuit boards are needed for devices.

8. Stability â€“ Better performance delivery is realized with vibration mechanical conditions. SMT connections are more reliable, it can reduce the dis connection risks during the final test.

SMT 3

Best Technology offers expert surface-mount technology services in China, along with manufacturing bare printed circuit board, flexible circuits, and MCPCB fabrication. With more than 15 years rigid PCB board experience, Best Technology has the resources, equipment, and know-how to produce your PCBs quickly and reliably.

different assembled board photo

Call Best Technology now and let us become your partner of PCB assembly service.

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How to clean the PCB assembled boards after soldering?

Friday, June 19th, 2020

Best Technology is a full turn-key assembly service company, we can supply the assembled board with very nice and clean surface.

Do you want to know how we control the cleaning process of PCBA? We would like to share the full cleaning process.

As we know, flux is used when soldering electrical components to a printed circuit board.

After assembly process finished, we need to remove all the unnecessary flux paste or other solder flux/ residue in order to avoid any quality issue.

Although it is a simple work, but to prepare some tools and preparation is necessary and important. Like wash board water, dust-free cloth, brush,Tweezers, static bracelets, finger gloves

Here is the how the cleaning process we made:

Step1:  

Use brush to brush the solder joint and solder flux on the soldered PCB. Applying some alcohol or acetone onto the brush, do not use too much pressure, as this may cause the solder point to break. Repeat the procedure as necessary, to remove remaining flux residue on the PCBA.

PCB assembly
Step1: Brush the solder joint and solder flux on the soldered PCB

Step2:

Wipe with a clean dust-free cloth to clean the assembled PCB.

Keep board clean and tidy to make sure no impurities and finger marks. Do the same process for bottom side.

PCB assembly
Step2:Wipe with a clean dust-free cloth to clean the assembled PCB.

Step3:

When above step finished, keep the board for an extra day to let the board dry enough before packing. Best QC guys will do final inspection for the finger prints under light. this will be helpful to check the cleaning result further.

PCB assembly
Step3:  final inspection for the finger prints under light

Step4:

Finally, use dust-free cloth to do the final cleaning and let the board dry and clean enough before package.

PCBA Cleaning process
Step4: use dust-free cloth to do the final cleaning.

Above are the process for how we clean the assembled boards.

Best Tech is a very professional manufacturer in printed circuit board and assembly. We clean each of assembled boards as the procedure we showed above.

If you are interesting to know more process for how we control the quality for the PCB assembled boards, contact us at any time, we will show you more.

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