PCBA Cleaning

The number of PCBAs used in the automotive, healthcare, aviation, communications and other industries is growing rapidly. Ensuring the functional reliability of these modules is therefore very important. Everything is further enhanced by miniaturization of PCBAs and their subsequent exposure to climatic influences (humidity, gases, temperature,…).

One solution to future problems is to thoroughly clean the PCBA surface after fitting components from flux residues, chemicals and other potentially harmful substances. Thorough use of cleaning agents on the surface consequently affects other process steps such as conformal coating. Poorly cleaned or uncleaned PCBAs can subsequently cause module failure in the final product.

How our systems/machines work and what are their main advantages – see our PCBA cleaning procedure. Or take a look at our case studies about PCBA cleaning. Our cleaning fluids will help you avoid these problems.

PCBA Cleaning After Soldering

Remove post-solder flux residues with a cleaning process built around the specific assembly, soldering material, required cleanliness, and production capacity.

DCT combines cleaning systems, cleaning fluids, rinsing, drying, and process validation. When a DCT cleaning system and DCT cleaning fluid are used together, DCT takes 100% responsibility for the functionality of the cleaning process.

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Review the selection process

One supplier for the cleaning system, fluid, and process

Worldwide availability: DCT supports customers through local distributors, technical sales managers, and demo centers.
Process responsibility: DCT takes 100% responsibility for the functionality of the cleaning process when the DCT machine and DCT fluid are used together.
More than 25 years of experience: DCT has developed cleaning agents, cleaning systems, and process-control solutions for electronics manufacturing since 2001.

Visit the DCT US website and worldwide network overview

Why should flux residues be removed from a soldered PCBA?

PCBA cleaning removes flux residues and other process contamination after soldering. The objective is a clean, rinsed, and dry assembly that meets the cleanliness requirement defined for the product and its next manufacturing step.

Cleaning becomes more demanding when residues are trapped under low-standoff components, assemblies contain complex connectors, or several soldering cycles have thermally stressed the flux. A result that appears visually clean may still require an ionic-cleanliness test when the application demands it.

Information needed before selecting a process

Exact solder paste, wire, or wave-flux designation.
PCBA dimensions, component layout, standoff heights, connectors, labels, inks, and sensitive materials.
Required production capacity per shift.
Required visual, ionic, coating, or customer-specific cleanliness criteria.
Available utilities, floor space, traceability needs, and preferred level of automation.

How DCT selects a PCBA cleaning solution

Define the contamination and acceptance criteria. DCT identifies the soldering material, critical component geometry, material-compatibility risks, required cleanliness, and throughput.
Test the actual assembly. Fresh production samples are cleaned with candidate fluids and process settings. Results are checked visually and, where required, by an appropriate analytical method.
Match chemistry and mechanical action. The fluid, temperature, time, pressure, holder orientation, rinsing configuration, and drying method are selected as one process.
Verify rinsing and drying. Dissolved residues and cleaning fluid must be removed from the assembly, and retained moisture must be addressed around connectors and low-clearance components.
Transfer validated settings to production. Final settings and capacity are confirmed for the selected machine configuration and real production load.

Cleaning-fluid starting points

Typical starting points that must be confirmed with the actual PCBA and soldering material
Cleaning fluid	Documented use	pH	Selection note
Decotron® 417XP	Post-solder flux residues, including modern no-clean solder pastes	pH-neutral	Frequently selected for difficult modern fluxes and assemblies with material-compatibility requirements. Compatibility still requires testing.
Decotron® CP381	Post-solder flux residues and selected combined applications	10-11	Alkaline, water-based fluid. DI-water rinsing is required, and the process must be checked against assembly materials.
Decotron® 411A	Difficult post-solder flux residues and under-component cleaning	11	Alkaline, water-based fluid with documented use on demanding residues. Some low-resistance plastics may be affected.

Review the DCT cleaning-agent category

Cleaning-system starting points by capacity

Documented capacity bands for PCBA cleaning
Required capacity	System starting point	Process consideration
50-300 PCBAs per shift	InJet® 388 or InJet® 388 TWIN configurations	Vertical high-pressure spray-in-air is used to reduce shadowing. The exact chamber and rinse configuration depends on the process.
300-600 PCBAs per shift	InJet® 3179 CRD BigBoard or selected InJet® 888 configurations	Board format, holder design, and the possible shadowing effect of a horizontal arrangement must be evaluated.
600-2,000 PCBAs per shift	InJet® 388 DOUBLE TRIPLE CRRD	Separate process chambers support high-capacity cleaning, pre-rinsing, final rinsing, and drying.

Review the DCT cleaning-system category

What does a complete PCBA cleaning process include?

Cleaning: The selected fluid and spray process release and dissolve the tested post-solder residues.
Draining or pre-rinsing: The process limits drag-out of contaminated cleaning fluid into the final rinse.
Rinsing: DI water removes released contamination and cleaning-fluid residues. Rinse-water quality must be controlled for the required result.
Drying: Hot air and, where required, focused compressed air remove retained water from components, connectors, holes, and other critical geometry.
Verification: Visual inspection, ROSE testing, microscopy, or another agreed method confirms whether the acceptance criteria were met.

Times and temperatures shown in laboratory reports apply to the tested samples and machine configuration. They are not universal settings for every PCBA.

Use evidence from the actual assembly, not a generic recipe

DCT test reports show that the same fluid can produce different outcomes when component geometry, thermal history, holder orientation, rinse quality, or drying requirements change. The recommended process is therefore based on a sample test and defined acceptance criteria.

Visual inspection identifies visible residues, staining, and material changes.
Microscopy supports inspection around solder joints and under accessible component edges.
ROSE testing can quantify extractable ionic contamination when that method is appropriate for the requirement.
Compatibility testing checks labels, inks, plastics, seals, metals, and other assembly materials.
Read the KOKI flux-residue case study
See why rinsing and drying matter

Frequently asked questions about PCBA cleaning

Can one cleaning recipe be used for every PCBA?

No. The soldering material, residue age and thermal history, component geometry, board materials, required cleanliness, load, and machine configuration can change the result. DCT confirms the process with representative samples.

Why is cleaning under low-standoff components difficult?

Small clearances restrict fluid exchange beneath the component. Chemistry, mechanical action, cleaning time, orientation, rinsing, and drying must work together, and some geometries can remain at the limit of what the process can reach.

Is a visually clean PCBA always ionically clean?

Not necessarily. Visual inspection and ionic-cleanliness testing answer different questions. The validation method should match the product requirement.

Why are rinsing and drying part of the cleaning result?

Cleaning releases contamination, but rinsing must remove both the released residues and the cleaning fluid. Drying must then remove retained moisture from connectors, holes, and other critical geometry.

How is the correct cleaning fluid selected?

DCT starts with the exact soldering material, PCBA construction, material risks, cleanliness target, and production capacity. Candidate fluids and settings are then tested on representative samples.

Can labels, inks, plastics, or seals be affected?

Yes. DCT reports document both compatible combinations and cases involving label lifting, ink changes, plastic sensitivity, or seal swelling. Compatibility must be checked during process validation.

Start with a representative cleaning test

Send DCT the exact solder paste or flux designation, representative freshly soldered PCBAs, target cleanliness, board dimensions, critical materials, required capacity, and any known drying challenges.

A DCT specialist can use this information to define the test scope and propose a machine, fluid, rinse, drying, and verification concept.

Email: info@dct.cleaning

Post-solder fluxes and solder pastes successfully tested and removed by DCT

The records below summarize documented DCT tests on soldered PCBs or PCBAs. They demonstrate prior experience, not a universal fluid recommendation. A current process must be confirmed with the actual assembly, soldering material, acceptance criteria, and production equipment.

Documented post-solder PCB and PCBA cleaning cases
Contamination / trade designation	Contamination type	Application / cleaned part	Successfully used DCT fluid	Documented test note
Alpha CVP 390V	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	All surface residues were removed in 5 minutes in the documented test.
Indium SN62 NC-SMQ92J Type 3	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	All flux residues were removed; label and ink compatibility varied by component.
Indium 8.9 HF Type 4	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	All flux residues were removed in the documented process.
Shenmao Nevo PF606-P30	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	Visual cleanliness required 15-20 minutes; at least 20 minutes was needed beneath components in the test.
ALPHA OEM 340	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	Documented tests achieved complete visual cleanliness with acceptable ionic-cleanliness results.
Senju SAC305 M705 ULT369	No-clean post-solder flux residue	PCBA after soldering	Decotron® 417XP	All flux residues and process contamination were removed in the documented process.
Alpha EF6850HF	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	All flux residues and process contamination were removed in the documented process.
AIM H10 SAC305 88.7-T4	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	All residues were removed in 5 minutes, including beneath a component with an approximately 150 µm standoff.
AIM V9 SAC305 88.5-T4	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	All residues were removed in 5 minutes, including beneath a component with an approximately 150 µm standoff.
Senju M705-GRN360-K1-V	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	Visible flux residues were removed after the cleaning time was extended to 15-20 minutes.
Senju M716-INJ7-32-11	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	Visible flux residues were removed after the cleaning time was extended to 15-20 minutes.
Senju M705 GRN360 K2-V	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	Visible residues were removed within 6 minutes; no material incompatibility was observed in the test.
Almit LFM-48W TM HP-I	No-clean post-solder flux residue	PCBA after soldering	Decotron® 417XP	All flux residues and process contamination were removed in the documented test.
KOKI S3X58-CF100-4	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	Visual inspection and ROSE testing documented complete cleanliness in the tested process.
Alpha OM 340	Post-solder flux residue	PCBA after soldering	Decotron® 417XP	The documented comparison achieved complete visual cleanliness with Decotron® 417XP.
KOKI S3X58-M500C	Post-solder flux residue	PCB after soldering	Decotron® 411A	Flux residues were removed from the surface and beneath components in the documented process.
Almit LFM-48U SUC-UI	Post-solder flux residue	PCBA after soldering	Decotron® 411A	Visual inspection documented complete cleaning after 10 minutes.
Koki SS48-M956-2	Post-solder flux residue	PCBA after soldering	Decotron® 411A	Visual inspection documented complete cleaning after 10 minutes; an aluminum cooler required the inhibited fluid variant.
Heraeus F645 IL-89M30	Post-solder flux residue	PCB after soldering	Decotron® CP381A	The recommended cycle left no visible flux residues in the documented test.
Alpha WB-700TF	Post-solder flux residue	PCBA after soldering	Decotron® 411	The tested sample achieved complete removal with no observed material incompatibility.
SMIC Senju Sparkle Flux WF-6317	Post-solder flux residue	PCBA beneath a BGA	Decotron® CP381A	The documented ROSE result after cleaning was 0.031 µg NaCl/cm².
Alpha OM-338 T45	Post-solder flux residue	PCBA after soldering	Decotron® CP381	Most residue was removed within 5 minutes, with the best documented result after 10 minutes.
Heraeus F 620	Post-solder flux residue	PCB after soldering	Decotron® CP381	All flux residues were removed after 15 minutes in the documented vertical spray-in-air process.
Almit SR-38 RMA LFM-48-S 3.5%	Post-solder flux residue	PCB after soldering	Decotron® CP381	All flux residues were removed after 15 minutes in the documented vertical spray-in-air process.
Alpha CVP-390	Post-solder flux residue	PCB after soldering	Decotron® CP381	All flux residues were removed after 15 minutes in the documented vertical spray-in-air process.
ROL0 pure rosin flux	Hand-soldering flux residue	Soldered PCB	Decotron® 411A	All flux residues were removed after one cycle; extended compatibility cycling identified component-marking limitations.
Alpha OM-338	Post-solder flux residue and ionic contamination	PCBA after soldering	Decotron® 411A	Visual inspection documented complete cleanliness and ion chromatography showed a significant reduction in extractable ions.
Interflux® DP 5505	Post-solder flux residue	PCBA after soldering	Decotron® CP381	All flux residues were removed after 6 minutes and complete visual cleanliness was documented.
Alpha® Telecore HF-850	Post-solder wire-flux residue	PCBA after soldering	Decotron® CP381	All flux residues were removed after 6 minutes and complete visual cleanliness was documented.
Senju M705-GLV-Type 4	Post-solder flux residue	PCBA after soldering	Decotron® 411A	The documented cleaning process successfully removed residues from the tested assemblies.
LFSOLDER TLF-201-111 M	Lead-free post-solder flux residue	PCBA after soldering	Decotron® 409	The tested PCBA was completely clean after 6-7 minutes.
LFSOLDER TLF287-171AT	Lead-free post-solder flux residue	PCBA after soldering	Decotron® 409	The tested PCBA was clean after 10-15 minutes.
Interflux IF2005C	Post-solder flux residue	Flex PCB after soldering	Decotron® CP381	Flux residues were completely removed after 5 minutes; the documented ROSE result fell from 2.042 to 0.281 µg NaCl/cm².
390-RX-HT soldering flux	Post-solder flux residue	PCBA after soldering	Decotron® 351S / Decotron® CP381	Flux residues were completely removed after 10-12 minutes in the documented test.
AIM M8	Post-solder flux residue	PCB after soldering	Decotron® CP381	Complete cleaning required 15 minutes around a critical component; the cleaned boards passed the ROSE test.
ALMIT LFM 48W TM-HP	Post-solder flux residue	PCBA after soldering	Decotron® 351S	The documented test achieved complete cleaning; paper-label compatibility required attention.
AIM NC257	Post-solder flux residue	PCBA after soldering	Decotron® 351S	The documented test achieved complete cleaning; drying depended on assembly orientation.
Alpha OM338PT	Post-solder flux residue	PCBA after soldering	Decotron® 351S	Visual inspection documented successful residue removal after 200 seconds.
EMIL OTTO S-250/FRO	Post-solder flux residue	PCB after soldering	Decotron® CP381	The tested PCBs were completely free of residues.
SHENMAO PF606-P245-T4	Post-solder paste-flux residue	PCB after soldering	Decotron® CP381	The tested PCBs were completely free of residues.
AIM NC258 SAC305	Post-solder flux residue	PCB after soldering	Decotron® 351S	The documented ROSE result decreased from 0.316 to 0.026 µg NaCl/cm².
SSA48-M955	No-clean post-solder flux residue	PCBA after soldering	Decotron® CP381	The fully automatic cleaning, rinsing, and drying process achieved the documented target result.
KOKI S3X58 M500	Post-solder flux residue	PCB after soldering	Decotron® 356S	Complete removal was documented after at least 10 minutes in the tested ultrasonic process.

InJet®

InJet® 388 CRRD 1PR "Combo"

The InJet® 388 CRRD “Combo” is primarily designed for precision plate cleaning after soldering. The cleaning system can also be used for high-quality removal of solder pastes and SMT adhesives...

InJet®

InJet® 388 TWIN CRRD "Sausage dog"

InJet® 388 TWIN CRRD “Sausage Dog” is developed primarily for high-capacity and precise plate cleaning after soldering. The cleaning system can also be used for high-capacity removal of solder pastes...

InJet®

InJet® 388 DOUBLE TRIPLE CRRD

The InJet® 388 DOUBLE TRIPLE CRRD offers more than twice the cleaning capacity of the InJet® 388 TRIPLE CRRD and is a high-performance vertical spray system for cleaning boards after...

DECOTRON®

Decotron® CP381

Water-based cleaning fluid determined to clean misprints and remove flux residues from PCBs after the soldering process. Ready-mix, intended for direct use. Intended for use in all types of DCT...

DECOTRON®

Decotron® 351S

Water-based cleaning fluid determined to clean misprints and remove flux residues from PCBs after the soldering process. Intended for use in all types of DCT cleaning machines, mainly in the...

DECOTRON®

Decotron® 411A

Water-based cleaning fluid determined to remove flux residues from PCBAs after soldering process. Can be used to clean misprints. Ready-mix, intended for direct use. More effective cleaning under components. Intended...

PROTON®

Flux Remover 4

Precision Rework Solutions: Maximizing PCBA Reliability with FLUX REMOVER 4 In the high-stakes environment of Surface Mount Technology (SMT), the margin for error is shrinking alongside component sizes. As component...

Other

DI water

DCT Deionized water intended for dilution of concentrates of cleaning fluids and as a rinsing medium. For a professional use for dilution of concentrates of cleaning fluids and as a...

InJet®

InJet® 388 CRD 2PR

The cleaning system is developed primarily for cleaning boards after soldering or for a combination of board cleaning and for removing solder paste and SMT adhesives from stencils, PumpPrints, squeegees...

Software support

Traceability ONLINE

1. Basic Traceability Data: Records times, temperatures, conductivities, and program numbers. Output: CSV/XML files on PC HDD. Barcode Reader: PLC ready; choose standard or own reader. Network: Set IP, copy...

Software support

Traceability OFFLINE

The basic version of Traceability is when general process data like set times, temperatures, conductivity levels, conductivity, and cycle number are stored to CSV file in a cleaning system onto...

DECOTRON®

Decotron® 417XP

Unique water-based, pH-neutral cleaning agent designed to remove flux residues from PCBAs after the soldering process. Ready-mix, intended for direct use. Revolutionary cleaning of modern “no-clean” solder paste flux without...

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100% RESPONSIBILITY FOR THE CLEANING PROCESS

We take full responsibility for the functionality of the cleaning process.

Complete cleaning solutions

We can offer complete cleaning solutions for all existing applications.

Quality of cleaning systems

We manufacture cleaning systems exclusively in stainless steel because it has long-term advantages.

pure quality of cleaning agents

We care about the functionality of the cleaning chemistry, but also about ecology.

Technical and economic improvements

With every project, our greatest motivation is to bring the customer a better technical and economic solution.

Development and customization

By continuously developing our cleaning technologies, we are moving forward and responding to developments in the electronics industry.

Democenters Worldwide

We give customers the opportunity to actually test the cleaning solution.

Direct service Support

For us, service support does not end with the installation, it begins.

For 40 years, SEHO Systems GmbH has been the world’s leading manufacturer of complete solutions for soldering processes and automated production lines. Many pioneering innovations in the field of soldering have their origin in SEHO. With our modern, innovative systems and the high quality standard of our products, we are a strong and reliable partner for our international customers. DCT Czech s.r.o. provides us with the ideal system solution for the cleaning processes required in our technology centre. Thanks to the comprehensive solution from DCT Czech s.r.o. we are very successful in cleaning the filter systems of our soldering lines as well as soldering accessories such as soldering frames used in wave soldering processes. We use the INJET 888 CRRD in conjunction with the Decotron T383 cleaning fluid from DCT. We are very satisfied with this technology because it meets the most demanding requirements in the cleaning process.

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SEHO Systems GmbH

Frank Schneider

application technician

Continental Automotive Czech Republic – Frenštát pod Radhoštěm is assembling PCBs for a major automotive client that requires maximum reliability of all its parts. Due to these high quality requirements, we were looking for a suitable supplier who could set up the entire cleaning process after soldering these PCBs. By working with DCT, we were able to gradually eliminate most of the technical problems associated with the cleanliness of the parts and satisfy a very demanding customer. What we appreciate most about our cooperation is the expertise of the DCT team and their ability to flexibly address emerging technical issues and the more stringent requirements of the end customer.

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Continental Automotive Czech Republic

Zbyněk Zahradil

Quality Department

We have been cooperating with DCT since 2006. We use DCT washing processes for cleaning: stencils, PCB overprints, soldering frames, filters from reflow ovens and also for manual cleaning. We are very happy and satisfied with our cooperation with DCT. We appreciate the support directly from DCT, but also from local DCT specialists.

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Celestica Romania

Bogdan Opris

NPI Press Engineer

DCT Czech helped us to solve the application of cleaning the printing templates from the residues of solder paste and SMT glue and at the same time cleaning the soldered PCBs from the residues of flux. After implementing the new Injet 388 mCRD cleaning technology and Decotron CP381 cleaning agent, it is possible to clean all parts in one cleaning machine with one type of cleaning fluid. A comprehensive solution has thus been achieved that ensures long-term stable cleaning results. We are also working with DCT Czech to improve other cleaning processes in our production.

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Connectgroup

Miroslav Černý

Process Engineer

At Tyco Fire Protection Products, our primary focus is on fire protection products and services. With the transition to lead-free soldering, we have struggled with the quality of washdown results for PCBs after the soldering process. Thanks to our long-standing relationship with DCT Czech, their expertise in cleaning, flexibility and customer solution orientation, we successfully changed and implemented a new PCB cleaning process using vertical spraying. DCT Czech designed and manufactured a high-capacity cleaning system for us, which we have been using successfully for almost 2 years.

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Tyco Electronics

Radek Matuška

Process Engineer

Since the opening of our new facility, we added both the InJet®388 for cleaning stencils and AirJet®594 for washing reflow heat exchangers. We requested multiple custom design changes for the InJet and DCT worked with us to modify the machine accordingly. We run 24/7 and have had exceptional service with DCT night/day/weekend. The machines are built very well and we haven’t had any major hardware or software issues for the last 2 years.

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Continental Corporation

Christopher Treadway

SMT Manager