How To Clean PCB- Everything You Need To Know in 2024

Introduction

How to clean PCB- It’s a common query for those who are frequent users of electronic applications. In most cases, personal digital assistants suffer from dust, corrosion, moisture contamination, etc. These cause serious damage to circuit boards.

PCBMay offers reliable services to clean electronic circuits at affordable costs. Do you know the process of cleaning PCBs?

Don’t worry. This article will cover all the necessary details related to PCB cleaning processes. We hope it will help save your device from abuse. Let’s make a move.

Why Is PCB Cleaning Important

PCB is undoubtedly the most crucial part of electronic appliances. It contains vital components that control the entire mechanism of a device by maintaining perfection. That’s why PCB needs to keep away from external contamination so that you can get the optimum output from a device.

PCB Cleaning Through IPA

PCB Cleaning Through IPA

But you can’t keep a circuit board in a completely compact zone. It must have gone through contaminants. So, there is a huge possibility of a PCB malfunctioning. On that note, the importance of PCB cleaning will be brought to the book.

You need to clean the dust on a regular basis so that it can remain functional for an extended period. Besides, removing corrosion, solder fluxes, conformal coating removal, etc are also equally important.

All of these ensure a high-quality, durable circuit board in the long run. So, you need to have proper knowledge on how to clean the PCB board to upgrade your device’s performance.

First, it is required to know how a PCB gets contaminated. If you have a clear understanding of the problems, you can find the solutions properly.

The Ways A PCB Gets Contaminated

Various contaminants (Both dry and wet) are responsible for damaging a printed circuit board. Such as-

Dry Contaminants

If you survey a wide range of damaged electronic devices, dry contaminants are the sources of most of the damages. Dirt, dust, etc reduce the longevity of electronic components.

Besides, dry elements can reach complicated portions of PCB designs. You can’t clean them through brushes from those places. You need to use compressed air or a vacuum cleaner to clean dust from problematic zones.

PCB Contaminated By Dirt

PCB Contaminated By Dirt

Wet Contaminants

Wet materials like moisture, flux, water, grime, oil, etc are the silent killers of circuit boards. These contaminants can hamper electrical and mechanical properties.

So, what to do?

You can use Acetone or Isopropyl Alcohol to remove wet contaminants from the PCB surface. Again, you have an option to apply demineralized water while removing moisture at low temperatures.

Dependable Ways Of Cleaning PCBs

Proper cleaning of a printed circuit board mostly depends on the method you are using. That’s why you need to have a clear conception of various processes used in removing dust and dirt from the PCB.

Removal Of Dust From The PCB Surface

Removal Of Dust From The PCB Surface

The safest and most convenient ways include-

Cleaning Through IPA (Isopropyl Alcohol)

Because of being economical, IPA is the most common PCB cleaner nowadays. This Alcoholic solution contains a lesser amount of chemicals compared to other PCB cleaners. It also evaporates quickly.

That means this PCB cleaning solution offers sustainability while being used as a cleaning solution. Usually, 90% IPA is the most appropriate for manual cleaning.

If you use more concentration, there is a chance of damaging the human body while contacting this solution. Don’t forget to use gloves and goggles during their use.

Cleaning Through Compressed Air

When you want to clean a small amount of dirt and dust from the circuit board, using compressed air is the best option for you. You need to use short bursts to apply air into the ventilation ports.

If you find more specks of dust in some critical portions of PCB, reassemble the circuit board and apply compressed air carefully.

Cleaning Through Distilled Water

Distilled water is a poor conductor of ions. That’s why it is often mixed with the cleaning solution.

Cleaning Through Baking Soda

The chemical name of Baking soda is Sodium Bicarbonate (NaHCO3). You can clean grime accumulated on the circuitry without causing minimum damage.

This chemical compound also offers abrasive properties that help remove corrosion to a certain extent. It is effective to dissolve the damaged portion. Besides, baking soda can neutralize the acidic property of dirt because of being a basic compound.

PCB Cleaning Through Ultrasonic Machines

If your circuit boards suffer from bubbles during operations, you can rely on ultrasonic cleaning machines to clean bubbles. Do you have any idea about ultrasonic sounds?

Let’s find out.

Ultrasonic PCB Cleaner

Ultrasonic PCB Cleaner

Ultrasonic sounds have a higher frequency compared to the normal audible range of the human ear, which lies between 20 to 20000 Hz. These sounds have some demerits due to causing damage to electronic components while dealing with grime and dirt.

These PCB cleaning machines imply high-frequency signals to create cavitation that acts to clear a bunch of bubbles produced on a PCB surface. You can clean dirt and grime from the most difficult portion of high-density circuit boards through ultrasonic machines.

Usually, this technique is suitable for THT (Through-Hole Technology). Its fast operations are quite impressive for high-volume PCB manufacturing and maintenance. Check this video to get a better idea:

How Does An Ultrasonic PCB Cleaner Function?

An Ultrasonic PCB cleaner functions through ultrasonic sound waves. Here, transducers create bubbles at the lower portion of the ultrasonic cleaner tank. Besides, generators excite these bubbles to ultrasonic frequencies.

When these bubbles implode, they clean all the dirt on the surface of the PCB. Actually, cavitation is a complicated and sensitive task to do. It is necessary to keep the temperature and pressure more than 10000 ⁰F and 10000 PSI, respectively during the implosion of bubbles.

Ultrasonic PCB cleaners are capable of producing up to 100KHz frequency. Usually, a lower frequency is more appropriate to produce larger bubbles compared to higher frequencies.

That means you can clean a larger space of dirt, and wet contaminants by using a low frequency of ultrasonic sound. In the most sophisticated and polished PCB surfaces, higher frequencies are widely used.

Ultrasonic Cleaner Transducer

Ultrasonic Cleaner Transducer

But lower frequencies can clean fabricated metallic portions with excellent reliability. So, get confused?

Don’t worry. You should focus on your preferences and use the suitable frequency as required.

Necessary Equipment For PCB Cleaning

The success of PCB cleaning depends on the effectiveness of equipment to a large extent. You need to manage high-quality cleaning tools to ensure the safe removal of dust and dirt. But do you know which tools are widely used for this purpose?

We are here with a list of important and common tools which are used in your attempt to clean PCB at home. Let’s have a look.

Brush

You should choose a brush containing soft bristles while dealing with how to clean PCB dust. Besides, a small-size brush can easily go through various dirty zones. So, you must focus on collecting a brush having a suitable size and soft bristles.

Usually, manufacturers and cleaning service providers deliver brushes as per your requirement. If not, you can use a toothbrush or a paintbrush.

PCB Cleaning Through Soft Brush

PCB Cleaning Through Soft Brush

Cotton Swab

Otton helps attach cleaning solvent to the dirty portion of the PCB surface. Usually, cotton swabs are compatible with IPA which indicates their high acceptability and outstanding performance.

IPA

This is a very common solvent used for PCB cleaning.

Towels

You must use lint-free towels to rub and dry the printed circuit boards. You can’t find any huge shed of debris. Towels enable you to eradicate unwanted materials from the contaminated portion of the PCB.

Blow drier

Using a blow dryer instead of an oven will be a smart choice for you. It helps dehydrate extra moisture or other wet contaminants after the completion of cleaning.

Flux Remover

A solder flux remover allows you to remove flux after soldering.

Except for these, you need to use Aerosol, trigger spray, vapor degasser, etc for cleaning your circuit boards. You can see the manuals delivered by the manufacturer to know how to clean PCBs.

Proper Ways Of Using PCB Cleaning Tools

  • Use the brushes only in the problematic areas.
  • Ensure a moderate evaporation rate
  • Don’t let the PCB completely dry out because it causes the drying of partially solvated solder fluxes.

PCB Cleaning Tool

PCB Cleaning Tool

Step-by-Step Process OF PCB Cleaning Though IPA

IPA (Isopropyl Alcohol) is a popular ingredient for cleaning circuit boards. This material helps remove the germs, moistures, fluxes, and conformal coatings without causing significant damage to the PCB components.

IsoPropyl Alcohol

IsoPropyl Alcohol

The necessary steps how to cleaning PCB with Isopropyl Alcohol include-

Getting The Materials Ready

First, you need to gather 99% Isopropyl Alcohol, cotton swabs, and a pot. It is highly important to arrange all of these things before starting the cleaning procedure.

PCB Cleaning

Take the necessary amount of IPA in your pot and dip a cotton swab into the Alcohol. You need to squeeze the cotton swab to remove excess solutions if any. Then, brush the cotton on the circuit board to clean dirt, dust, flux, etc.

You can dip the cotton again to keep it wet as much as required.

Dry The PCB

In most cases, users forget this step and don’t get the desired result of cleaning PCB. But you should not make the same mistake, shouldn’t you?

It is highly recommended to dry the clean circuit board for at least 30-40 minutes before further use.

One last thing about IPA. Don’t forget to collect it from a registered or high-class source. It will increase the durability of PCB in the long run.

How Does Corrosion Hamper A PCB?

Corrosion hampers a printed circuit board in multiple ways. Have you ever thought of the causes of corrosion and its consequences?

Usually, metallic components having no shield react with air and create rust. Rust, also known as Iron Oxide, is a less-conductive material. This is the most familiar type of corrosion that happens in electronic applications.

Corrosion In PCB Surface

Corrosion In PCB Surface

Besides, the following points are the common reasons for causing corrosion-

  • Leaving an electronic device or PCB without drying up properly.
  • Exposure of metallic connections to the oxidants of nature, like Oxygen, Hydrogen, Sulfur, Nitrogen, etc.
  • Leakage of acid from a defective power source
  • Getting connected to salty water or air

You must remove corrosion from the PCB surface as soon as you notice this effect. If you leave it by paying less attention, your circuit board will turn into a faulty element within a short period. So, never underestimate corrosion in the case of PCB.

The Safest Way To Clean Corrosion From PCB

Initially, it is necessary to manage the cleaning tools required for removing corrosion from PCB. As we mentioned the equipment list for PCB cleaning earlier, you have already come to know the basic preparations.

After that, it’s time to create the cleaning solution and make the PCB ready for restoration.

How To Clean PCB Corrosion

  • Mix a couple of tablespoons with a quarter-cup of baking soda or IPA until it gets the required thickness.
  • You can make note of the PCB design configuration to ensure easy re-assembly after the cleaning.
  • Disconnect chips and cables attached to the circuit board.
  • Dip the brush into the cleaning solution.
  • Scrub the corroded PCB surface with the brush carefully.
  • After covering the whole space affected by corrosion, wait for around 30-40 minutes to get it dry.
  • Rinse the PCB to remove the solution from the PCB. You can also use a wet brush to clean IPA or baking soda solution if rinsing is not possible.
  • Apply a phosphate-free cleaner to the PCB and wait for around 20-30 secs.
  • Scrub the circuit board again with a toothbrush or paintbrush.
  • Rinse the PCB
  • Dry it by using a lint-free towel.
  • Heat the circuit board until all the wet materials and moistures get removed completely. It may take time. But you need to do this properly to get the desired output.
  • Reassemble the circuit board.
  • Check its functional properties before using it.
  • In the case of any corrosion that remains on the surface, apply an eraser to remove it.

Solder Flux Removal From PCB Surface

Soldering is an effective process of connecting two metals having low melting points. Solder flux protects the solder joints from metallic oxides. Fluxes get accumulated on the pins of electronic chips during the soldering.

Cleaning Solder Flux

Cleaning Solder Flux

That’s why it is important to remove solder flux from the PCB surface. Its removal can improve the functionality and longevity of solder joints.

But how do you remove it safely?

You can easily fix the problems of solder flux attachment by using the following materials-

  • 90% IPA
  • Soft and short brush
  • Microfiber cloth or lint-free towels

What next?

The removal process is very easy. You just need to get the bristle brush through IPA and scrub the PCB. You have to continue the process until all solder flux gets removed. Then, dab the PCB with a microfiber cloth. You can also incorporate a lint-free towel for this purpose.

You can watch this video about solder flux removal:

Effect Of Solder Flux Type In PCB Cleaning Process

Solder flux types have a significant effect on PCB cleaning processes. It is highly important to match the flux types and solvent types.

Usually, regular flux removers are compatible with R, RMA, and RA fluxes. They can easily clean these solder fluxes from the PCB surface. You can imply IPA to remove them.

But what should you do in the case of solder fluxes which are more difficult to clean?

It is essential to use aggressive solvent in this event. Besides, using brushing is more effective for no-clean flux.

When you have the intention of removing aqueous fluxes, you can use Alcoholic solvents. In this case, you can also incorporate deionized water.

Moreover, you need to consider the concentration of PCB cleaner, temperature rise, cycle time, etc while choosing the flux remover.

Reliable Way Of Cleaning A Wet PCB

Electronic equipment often gets connected to water or liquid substances. If you find a wet circuit board, it is not mandatory to replace the whole board. You can clean the wet portion conveniently if you follow a reliable procedure.

In the initial stage, you need to gather 90% IPA, container, distilled water, soft brush, blow drier, etc. Then, disassemble the device and turn it. Next, you need to remove the battery and shake enough to ensure safe drainage of liquid.

Cleaning A Wet PCB

Cleaning A Wet PCB

Now, you have come to the most crucial part of the cleaning process. Do you know what to do now?

In this stage, you have to place the circuit board in a container with an IPA solution. In the case of the unavailability of Isopropyl Alcohol, you can use distilled water.

Next, pick the PCB from the cleaning solution and remove the remaining grime through a bristle and soft brush. You need to use the brush carefully so that the PCB components don’t get damaged.

Then, use a blow dryer to dry the whole circuit board properly. After completing this task, check all components and replace the defective materials, if any.

In the end, you need to assemble the circuit board and place it into the device carefully.

The Most Suitable Time To Apply Final Rinse

You need to apply the final rinse when solvated flux residues get removed from the corners and under PCB components. Final rinsing indicates that there is no flow of PCB. Improper use of rinse can cause latent ionic contamination.

Besides, it increases the time of the PCB cleaning process to a large extent. That’s why always apply the final rinse at a suitable moment.

How To Clean Under Components Of PCB

Using an Aerosol flux remover is an impressive way to clean under components of a circuit board. It is easier to clean a faulty component whose both sides are exposed. You can pass the solvent directly to the corners that help break any kind of dam produced by flux there.

The more you find the open channels, the more the chance of getting solder flux exposed to solvent. Then, you can remove the maximum portion of flux from the lower portion of PCB components.

You have an opportunity of using both static and oscillatory spray in this case. It depends on the component size to a large extent.

Basically, moving spray allows you to cover the maximum portion beneath the PCB components. It can be used from various sides and angles.

It is beneficial to use stationary spray for a small size component and vice versa.

Considerable Factors For A Hassle-Free Flux-Residue In PCB Cleaning

There are various factors that influence the process of removing flux residue. If you can control these factors, it will be easier for you to upgrade the PCB performance. The most crucial variables for how to clean PCB after soldering are-

Type Of Solder Flux

Different solder fluxes have separate cleaning mechanisms. Such as tacky solder flux requires more cleaning time and additional agitation. You must apply the right cleaning process considering the strength of the solder flux to remove.

Lead-Free Soldering

Manufacturers prefer lead-free soldering for its immense positive points. But its removal is a little bit complicated. You have to imply highly activated flux removers and a high temperature while cleaning this type of solder fluxes.

PCB Lead-Free Soldering

PCB Lead-Free Soldering

Interval Between Soldering And Cleaning

You need to keep the time interval between soldering and its cleaning as minimal as possible. Otherwise, solder fluxes get harder and more difficult to remove within time.

Temperature

Excessive soldering temperature can melt the flux residues in many cases. Then, it becomes more complicated to clean. That’s why the cleaning period to soak time, etc are also increased.

Type Of Flux Remover

You should choose the flux remover and agitation concerning the thickness and hardness of solder flux residues.

Conclusion

It’s a great concern for all who deal with PCB to get a dependable solution on how to clean PCB. If you have the right knowledge about the ins and outs of different cleaning mechanisms, along with challenges, you can optimize the PCB performance through proper cleaning.

PCBMay provides PCB assembly and manufacturing services ensuring firm reliability. You can depend on us to take care of your PCB cleaning and keep them functional like a new circuit board.

We hope you have already got the answers to your queries based on PCB cleaning. Stay tuned to get more up-to-date information about different PCBs.

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