Posts Tagged ‘PCB Assembly’

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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How to Choose a Professional PCB Assembly Company

Monday, November 18th, 2019

Hardware designers requiring turnkey PCB assembly services usually face tremendous obstacles for their need of prototyping and small batches. Large companies with huge inventory needs and long delivery horizons can wait for days or weeks for a proposal, while accepting large minimum quantity requirements. For them, delays associated with overseas manufacturing are no big deal. However, these conditions are simply unacceptable for small industries, engineers, makers, and entrepreneurs.

Best Practices of PCB Assembly Vendor

Selecting the professional PCB assembly company at the beginning determines the success of a project. Therefore, picking the right PCB assembly services provider becomes a highly important decision to be made. One must watch out for those offering very low prices, but subsequently are unable to provide the services, record of accomplishment, infrastructure, and technology to back up their promises. Rather, one must insist the PCB assembly services have the essential features, offer the services, and follow business practices such as:

Instant Quotations

Waiting for days or weeks and trading a bunch of emails only to find out the cost of a PCB assembly, is not only a waste of time, it is expensive. A vendor offering instant, online quotations is always preferable. In general, although all vendors will start by sending a quotation for the project, therefore, selecting one who gets the process off painlessly is advisable. Moreover, selecting the vendor who gives an estimate in terms of quantity offtake helps in determining capital needs and product prices.

Prototyping Requirements

Most customers, before placing their order, want to make sure their PCB works exactly as intended. This may require making a few iterations to perfect the design. So far, prototyping was a big challenge under the old manufacturing model. However, Best Technology is willing to handle even a single quantity.

Minimum Order Requirements

Earlier, PCB assembly services were unable to accept production runs of small quantities. Older technology did not allow profitability in smaller numbers, which turned out to be a major challenge for everyone. However, use of modern technologies allows easy combination of small orders into larger ones, while switching from one task to another is no longer a major hurdle. Therefore, professional PCB assembly providers accept all types of order, regardless of quantity, and execute them at reasonable prices.

Seamless Manufacturing

With advancement in PCB assembly technologies, it is no longer necessary to track multiple vendors and suffer long lead times. A modern PCB assembly solution such as the Best Technology, offers a platform to resolve any assembly problems, online and from anywhere and takes over the sourcing, purchasing, and assembly of the components. With this approach, the product can be expected to be available in days.

Looking Beyond PCB Assembly

The PCB happens to be only the first step of the many for most inventions and products and PCB Assembly is an especially non-negligible process. Quality can only be assured by finding a reliable company.

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PCB Assembly Fabrication Methods

Tuesday, November 12th, 2019

PCB or Printed Circuit Board assembly at Best Technology involves combining the bare PCB, electronic components, and other accessories effectively to allow the assembly to function as the designer intended. Generally speaking, the fabrication methods involve a number of major steps:

(1)Component placement

(2)Soldering

(3)Cleaning

(4)Inspection

(5)Testing

Component Placement

Methods of placing components on the PCB rely on several factors such as:

Single or double side component placement

SMD components only

Through-hole (TH) components only

Mix of SMD and through-hole components

A PCB may have components present only on one of its sides or on both, although assembling a PCB with through-hole components on both sides is a rare occurrence. Single side component placement with either all SMDs or all through-hole components is more common, while single sided PCBs with a mix of SMDs and through-hole components is also to be found.

For assemblies requiring SMDs on both sides of the PCB or a mix of SMD and through-hole components on the top and only SMDs on the bottom, the PCB assembly process must be broken up into several intermediate steps, and the assembler needs to take special precautions for each of them.

Soldering

Soldering is the process of joining two dissimilar metals using a molten filler metal alloy. The molten metal alloy enters the joint, and as it cools and solidifies, bonds with the adjoining metals. Primarily,  three common ways of soldering including manual soldering, wave soldering and reflow soldering are available.

Cleaning

After soldering is over, some flux residue may remain on the printed circuit board. Over time, this can turn acidic, and corrosively damage solder joints. The flux residue can also attract fingerprints and make the PCB look unclean.

Manual Inspection

Inspection is necessary at various stages of assembly. For instance, one stage of inspection is necessary when the operator has stuffed TH components into the board, and again once the assembly has undergone wave soldering.

Similarly, for reflow soldering, inspection is necessary once after solder paste printing is over, then again after mounting the SMD components, and once again after the boards have exited the reflow oven.

AOI & X-Ray Inspection

For large batches of PCB assembly, the manual inspection process may be too slow. A faster process is the Automatic Optical Inspection or AOI process. AOI machines have video cameras to capture images of the PCB, the components, and the solder quality, and they can compare the images with standard images in the machine’s memory. The AOI machines work at high speed processing a large number of PCBs within a relatively short time.

Electrical & Functional Testing

Electrical testing may be necessary after the assembly has passed through the above stages, to test whether the assembly functions as intended by the designer. This may involve programming the board, or calibrating certain components before the actual testing can begin.

Electrical and functional testing involves applying specific voltage/voltages to the circuit on the PCB and looking for normal/abnormal behavior at predefined outputs. Some tests may require a voltmeter and ammeter, while others may need more sophisticated instruments such as an oscilloscope or a waveform analyzer to complete the testing.

Conclusion

PCB assembly is a complicated process involving several technical processes with important setup parameters. Eminent assemblers such as Best Technology are always careful with these setup parameters to allow the final product achieve the desired quality.

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