PCB Cleaner: Things You Need to Know - PCBasic

04 Aug.,2025

 

PCB Cleaner: Things You Need to Know - PCBasic

Even PCBs that have been manufactured with high precision may cause short circuits, corrosion, or even product failure due to residual flux, dust, fingerprints, or moisture if they are not effectively cleaned. For this reason, PCB cleaning is necessary, to ensure the stability of electronic products and extend electronic devices’ service life. Whether you are an electronic DIY enthusiast, a product engineer, or a technician, understanding how to clean PCBs, mastering different types of circuit board cleaning methods, and choosing the appropriate PCB cleaner are all the basis for ensuring the long-term reliable operation of the equipment.

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Next, we will delve into various PCB cleaning techniques. It covers a variety of solutions ranging from manual cleaning to the use of automated equipment such as ultrasonic PCB cleaners and deionized water cleaning machines.

Overview of PCB Cleaning

PCB cleaning is not only about appearance, but also directly affects electrical performance and service life. After soldering, contaminants such as flux residue, dust, moisture or fingerprints usually remain on the PCB surface. These impurities may cause corrosion, short circuits or performance degradation of the circuit board. Therefore, it is necessary to clean the circuit board. Common cleaning scenarios include: post-soldering treatment, maintenance/rework process, treatment before applying protective coating, and treatment before long-term storage. The so-called PCB cleaner refers to the chemicals, tools or equipment used to remove these contaminants. Choosing the appropriate circuit board cleaner can effectively ensure the long-term stable operation of the circuit board.

Types of PCB Cleaners

Different types of PCB board cleaners are suitable for different contaminants and cleaning requirements. Choosing the right cleaning agent can not only effectively remove contaminants, but also prevent damage to circuit boards or affect the performance of electronic components. The following are several common PCB cleaners:

Solvent-based PCB Cleaner

This type of cleaner is based on highly volatile organic solvents and can quickly dissolve stubborn flux residues, grease, welding fumes and other contaminants. Common types of cleaners include isopropyl alcohol (IPA) or commercial flux cleaners. They are suitable for cleaning rosin and no-cleaning fluxes and are very commonly used in manual soldering and maintenance scenarios.

Water-based PCB Cleaning Solution

This kind of PCB cleaner focuses on environmental protection and low toxicity. It adopts deionized water or water-based chemical formulas, which are more friendly to the human body and the environment. It is usually used in conjunction with a spray cleaning system or a batch cleaning machine to remove water-soluble flux. This type of PCB cleaner is widely used in mass manufacturing and green electronic production.

Dedicated PCB Flux Cleaner

Dedicated solvents developed based on the type of flux (rosin, no-rinse, water-soluble) are more targeted. An excellent PCB flux cleaner can effectively remove the active residues around the solder joints and avoid leaving white deposits. It is suitable for military and medical PCB cleaning applications with high-reliability requirements.

PCB Cleaner Spray

PCB cleaner spray penetrates quickly and removes surface contamination by spraying. This cleaner is suitable for cleaning small areas or hard-to-reach parts. It is very convenient for on-site maintenance or repair personnel to use at will and is suitable for various scenarios of cleaning circuit boards.

Electronic Board Cleaner

This type of cleaner is specially designed for sensitive circuits and features anti-static, anti-corrosion and residue-free properties. This type of cleaner is suitable for high-precision equipment, such as communication base stations, industrial control systems, medical instruments, etc. It can safely clean the surface of the PCB without damaging the components, improving the overall system stability.

When choosing the most suitable PCB cleaner, it is not only necessary to consider the type of contaminants, but also to make a comprehensive judgment by taking into account the circuit board structure, component sensitivity, environmental protection requirements and cleaning methods. Next, we will introduce several common cleaning methods to you, mainly from the aspects of manual and machine cleaning.

Manual PCB Cleaning Methods

In sample making, rework or small-batch DIY projects, manual cleaning of PCBs is a common and practical method. Compared with automated equipment, manual methods have lower costs and are more flexible to operate. This way is suitable for cleaning local solder joint residues, flux contamination or slightly oxidized areas. So, how to clean the PCB manually?

First of all, it is necessary to prepare the required tools and materials. The basic tools and cleaning supplies required include: lint-free cloths/wiping paper, anti-static brushes, cotton swabs, compressed air cans, isopropyl alcohol (IPA) or flux remover, anti-static gloves, etc. Sure, if what you pursue is convenience, you can also use PCB cleaner spray. This type of circuit board cleaner spray has good solubility and rapid evaporation characteristics, and is an ideal choice for removing flux and oil stains.

Then, the formal cleaning process can begin:

Step 1: Evenly spray the PCB cleaner spray or isopropyl alcohol on the solder joints, pins or contaminated surfaces that need cleaning, and wait for a few seconds to allow it to penetrate and soften the flux residue. This step is the initial treatment of the contaminated area.

Step 2: Use an anti-static brush or cotton swab to gently scrub the contaminated area to help separate flux residues, dust or stains. This process requires patience and avoiding vigorous scratching to prevent damage to the solder pads.

Step 3: Use a lint-free cloth or wiping paper to remove the dissolved flux and dirt to prevent it from adhering to the surface of the circuit board again after drying.

Step 4: Use a compressed air tank or a hot air gun in the low-temperature setting to dry the PCB to ensure there is no liquid residue and avoid the risk of short circuits or corrosion.

Step 5: Use a magnifying glass or microscope to carefully observe the cleaning area again: checking if there is still flux residue or white powder, and whether there are problems caused by improper cleaning such as scratches, pad damage, burrs, etc.

If there are still residues, steps 1 to 4 can be repeated, or a more powerful PCB flux cleaner can be considered. Although manual cleaning is simple, only when the operation is standardized and the materials are properly selected can the goal of electrical safety and long-term stable operation be truly achieved. For complex or large-scale applications, it is still necessary to use the best PCB cleaner, such as automatic spray cleaning, ultrasonic or deionized water systems. Only in this way can higher consistency and efficiency be achieved, as well as more professional PCB cleaning.

Machine-Assisted PCB Cleaning Methods

For large quantities or complex circuit boards, equipment cleaning is required to achieve consistent and efficient results. Common cleaning equipment includes:

Ultrasonic PCB Cleaner

The PCB ultrasonic cleaner cleans by generating microbubble vibrations in the liquid through high-frequency sound waves. This machine can penetrate deep into cracks and crevices, effectively removing flux residues and particles. And it can be deeply cleaned without touching the circuit board, making it highly suitable for cleaning multi-layer boards and high-density components.

Vapour Phase Cleaning

The vapour phase cleaning machine dissolves contaminants by heating solvent vapor and is suitable for removing no-cleaning fluxes. It has the advantages of high efficiency and suitability for industrial-grade dense circuits. However, good ventilation is required and attention should be paid to operational safety.

Spray-in-Air Systems

This type of system applies the cleaning solution to the PCB surface through a high-pressure nozzle and then dries it with an air knife. The Spray-in-air systems are suitable for large-scale cleaning and are widely used in SMT assembly lines.

Dishwasher-Type Batch Cleaners

This device is similar to an industrial dishwasher and is often used for batch PCB cleaning. It has high consistency and the cleaning, rinsing and drying process is fully automatic.

Deionized Water Cleaning Machine

The deionized water cleaning machine can effectively remove particles, oxides and organic residues by combining surface activation and ultrapure water to rinse PCBs. This type of cleaning machine is an ideal choice for aerospace, medical and other applications that require ultra-clean surfaces. Its environmentally friendly and non-corrosive process is conducive to improving the reliability of subsequent adhesion, coating and welding. Moreover, this device has zero residue, no scale or metal ions, and is highly safe.

How to Choose the Suitable PCB Cleaning Method?

How can we clean circuit boards efficiently and safely in the face of various cleaning devices and methods? Here are some common scenarios and frequently used methods. Hope they can be of some help to you:

Application Scenario / Need

Recommended Cleaning Method

Small batch soldering, prototyping, or repair

Manual cleaning

Post-solder flux removal

Solvent-based localized cleaning

High-volume production

Automated cleaning systems

High-density or complex PCBs (e.g., BGA, QFN)

Ultrasonic cleaning

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Water-soluble flux or ionic contamination

Deionized water cleaning (eco-friendly)

Spot cleaning or field repair

Spray-type cleaner

Eco-friendly and non-corrosive requirements

Water-based or plasma cleaning

Conclusion

Learning how to clean circuit boards is a basic skill that every electronics professional must master. Whether it is sample boards, repair parts or batch products on the production line, choosing the appropriate PCB cleaning methods and tools can greatly enhance the reliability of the products. Selecting the best PCB cleaner is the key to ensuring the stable operation of electronic products. After reading this article, you must have gained more understanding of PCB cleaning. Of course, if you need clean high-volume PCBs, you can also contact PCBasic!

About PCBasic

The Engineer's Guide to Choosing the Right PCB Cleaning Equipment

As an electrical engineer, selecting the right PCB cleaning equipment is crucial to ensure the reliability and performance of printed circuit boards (PCBs). Whether you're dealing with flux residues, ionic contamination, or other debris, the wrong equipment can lead to damaged components or inefficient cleaning. In this guide, we’ll walk you through the key factors for PCB cleaning equipment selection, offer a detailed PCB defluxing equipment guide, help with choosing a PCB cleaning system, and explore options for ionic contamination removal equipment. Let’s dive into the essentials to help you make an informed decision.

Why PCB Cleaning Matters for Engineers

PCBs are the backbone of electronic devices, and any contamination—whether it’s flux residue from soldering, dust, or ionic compounds—can cause short circuits, corrosion, or signal degradation. For engineers, maintaining clean boards isn’t just about aesthetics; it’s about ensuring long-term functionality and meeting industry standards like IPC- for PCB cleanliness. Studies show that up to 30% of PCB failures are linked to contamination-related issues, making proper cleaning a non-negotiable step in manufacturing and repair processes.

In this blog, we’ll break down the types of equipment available, key considerations for selection, and practical tips to match your specific needs. By the end, you’ll have a clear roadmap for choosing the best system for your projects.

Understanding the Basics of PCB Cleaning

Before jumping into equipment selection, let’s cover why and how PCBs get dirty. During assembly, soldering flux is used to improve solder joint quality, but leftover residues can attract moisture and lead to corrosion. Ionic contamination, often from salts or acids, can cause electrical leakage, reducing performance. Dust and debris from handling or environmental exposure can also interfere with connections.

Cleaning removes these contaminants, ensuring reliability. The process varies based on the type of PCB (single-sided, double-sided, or multilayer), the contaminants present, and the production volume. As an engineer, your goal is to pick equipment that balances effectiveness, cost, and compatibility with your workflow.

Types of PCB Cleaning Equipment

There are several types of PCB cleaning systems, each suited for specific applications. Below, we’ll explore the most common options to guide your PCB cleaning equipment selection.

1. Manual Cleaning Tools

For small-scale operations or rework, manual cleaning with brushes, swabs, and compressed air can be effective. These tools are affordable, with basic kits costing between $20 and $100, and are ideal for spot cleaning or low-volume tasks. However, they lack consistency and aren’t suitable for ionic contamination removal, as they can’t ensure thorough cleaning across complex boards.

Best For: Prototyping, repairs, or hobbyist projects.

2. Ultrasonic Cleaners

Ultrasonic cleaners use high-frequency sound waves (typically 20-40 kHz) to create cavitation bubbles in a cleaning solution, dislodging contaminants from PCB surfaces. They’re highly effective for PCB defluxing equipment needs, removing flux residues and particles from hard-to-reach areas like under components. Prices range from $100 for small benchtop units to $5,000+ for industrial models.

Best For: Small to medium batches, intricate boards with tight spaces.

Caution: Ensure components are rated for ultrasonic exposure, as delicate parts may be damaged by vibrations.

3. Spray Wash Systems

Spray wash systems use pressurized jets of cleaning fluid (water-based or solvent-based) to blast contaminants off PCBs. They’re often automated, making them efficient for medium to high-volume production. These systems can cost between $2,000 and $20,000 depending on capacity and features like closed-loop filtration.

Best For: Assembly lines, consistent cleaning of larger batches.

4. Inline Cleaning Systems

For high-volume manufacturing, inline cleaners integrate directly into production lines, cleaning PCBs as they move through assembly. These systems are customizable for ionic contamination removal equipment needs, often using deionized water to prevent residue. Costs start at $50,000 and can exceed $200,000 for advanced setups.

Best For: Large-scale production with strict cleanliness standards.

Key Factors in Choosing a PCB Cleaning System

When choosing a PCB cleaning system, engineers must weigh several factors to ensure the equipment meets project demands. Let’s break down the critical considerations.

1. Type of Contaminant

Different contaminants require different cleaning methods. Flux residues often need solvent-based or semi-aqueous cleaners, while ionic contamination demands deionized water to prevent conductive residues. Dust and debris might only need dry methods like compressed air. Identify the primary contaminants in your process to narrow down equipment options.

Example: If you’re working on lead-free solder assemblies, no-clean flux residues are harder to remove and may require a more aggressive ultrasonic or spray system with specialized chemistry.

2. PCB Complexity and Component Sensitivity

Multilayer boards or those with surface-mount components (SMT) have tight spaces where contaminants hide. Ultrasonic or spray systems excel here, but you must check if components can withstand the cleaning method. For instance, some MEMS sensors or quartz crystals can fail under ultrasonic vibrations.

Tip: Review component datasheets for cleaning compatibility or test a sample board before full-scale cleaning.

3. Production Volume

Your throughput dictates the scale of equipment. Manual tools work for a few boards per day, while inline systems are necessary for hundreds or thousands. A mid-range spray wash system might handle 50-200 boards daily, offering a balance for smaller manufacturers.

4. Cleaning Chemistry Compatibility

The cleaning fluid—whether solvent, water-based, or semi-aqueous—must match your equipment and PCB materials. Solvents are effective for stubborn residues but pose environmental and safety risks. Water-based cleaners are eco-friendly but may require longer drying times. Check if your chosen equipment supports the chemistry you need.

Data Point: According to industry reports, water-based cleaning systems have grown in popularity, with over 60% of manufacturers adopting them for environmental compliance.

5. Budget and Cost of Ownership

Equipment price is just one part of the equation. Consider maintenance, consumables (like cleaning fluids), and energy costs. For example, an ultrasonic cleaner might cost $1,000 upfront, but frequent fluid replacement could add $200 monthly. Inline systems have high initial costs but lower per-unit cleaning expenses in high-volume settings.

Special Focus: Ionic Contamination Removal Equipment

Ionic contamination, often from salts or acids in flux or handling, is a silent killer of PCB reliability. It can cause dendritic growth, leading to shorts, especially in high-humidity environments. Ionic contamination removal equipment typically uses deionized water or specialized solutions to eliminate conductive residues.

Key Equipment Options:

  • Ion Exchange Systems: Paired with spray or inline cleaners, these purify water to remove ions, ensuring no residue is left. Cost: $5,000–$15,000.
  • Conductivity Testers: Post-cleaning, these devices measure ionic residue levels to verify cleanliness per IPC standards (typically below 1.56 μg/cm2 NaCl equivalent). Cost: $500–$2,000.

Practical Tip: If you’re in a high-reliability field like aerospace or medical devices, invest in equipment with real-time monitoring of water purity to ensure consistent results.

PCB Defluxing Equipment Guide

Flux residues are a common challenge in PCB assembly, and choosing the right PCB defluxing equipment can make or break your process. Defluxing equipment must remove residues without damaging components or leaving secondary contaminants.

Top Considerations:

  • Cleaning Method: Ultrasonic cleaners are excellent for no-clean flux, while spray systems handle rosin-based flux better in high volumes.
  • Chemistry: Semi-aqueous cleaners offer a balance of effectiveness and environmental safety for defluxing. Ensure compatibility with your board materials—some solvents can degrade certain plastics or coatings.
  • Drying: Post-defluxing drying is critical to prevent moisture-related issues. Look for equipment with integrated drying or invest in a separate drying oven (cost: $500–$3,000).

Example: In a project involving high-density SMT boards, I used a benchtop ultrasonic cleaner with a semi-aqueous solution at 40°C for 10 minutes per cycle. This removed 95% of flux residues without affecting component integrity, as verified by visual inspection and conductivity testing.

Practical Tips for Engineers

Here are actionable tips to streamline your PCB cleaning equipment selection process:

  1. Test Before Scaling: Always run a small batch with new equipment to confirm compatibility with your PCBs and contaminants.
  2. Follow Industry Standards: Adhere to IPC cleanliness guidelines (like IPC-CH-65) to ensure your process meets quality benchmarks.
  3. Maintain Equipment: Regularly clean filters and replace fluids in ultrasonic or spray systems to avoid cross-contamination. For instance, dirty ultrasonic baths can redeposit particles, reducing effectiveness by up to 40%.
  4. Train Your Team: Ensure operators understand equipment settings and safety protocols, especially with solvent-based systems.

Common Mistakes to Avoid

Even experienced engineers can make missteps when choosing a PCB cleaning system. Avoid these pitfalls:

  • Overlooking Component Sensitivity: Using aggressive cleaning on delicate parts can lead to failures. Always check datasheets.
  • Ignoring Drying Needs: Residual moisture can cause corrosion. Budget for drying solutions if your equipment lacks this feature.
  • Choosing Based on Price Alone: Cheap equipment might save money upfront but could cost more in rework or failures. Balance cost with performance.

Conclusion: Making the Right Choice

Selecting the right PCB cleaning equipment is a critical decision for electrical engineers aiming to ensure reliability and performance in their designs. By understanding your contaminants, production volume, and budget, you can narrow down options—whether it’s a simple ultrasonic cleaner for defluxing or an advanced inline system for ionic contamination removal equipment needs. Use this guide as your roadmap for PCB cleaning equipment selection, follow our PCB defluxing equipment guide, and take a strategic approach to choosing a PCB cleaning system.

Remember, the right equipment not only cleans effectively but also integrates seamlessly into your workflow, saving time and preventing costly failures. Have a specific question or need tailored advice? Drop a comment below, and let’s discuss your unique challenges.

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