When is it advisable to test for ionic contamination?
Whether it’s production approval, a process change, a customer complaint, or a field failure: When the reliability of electronic assemblies is at stake, you need reliable measurement results. Our analyses show whether ionic residues are a critical issue, what the possible causes are, and what the next technically sound steps should be.
Fast, reliable
measurement results
- Determination of the sum parameter for ionic impurities using the ROSE Test
- Assessment of the ionic contamination (anions, cations and organic acids) present on the assembly using Ion chromatography
- Qualitative and quantitative resolution of substances using high-performance liquid chromatography (HPLC)
- Assessment of unknown substances based on the retention time
- Continuous quality monitoring and surface qualification
- Analysis in accordance with standards such as IPC TM-650 2.3.25, IPC TM-650 2.3.28 or customer-specific requirements
Detection of Ionic Contaminants According to IPC-TM-650
To detect ionic contaminants, we use the ROSE test in accordance with IPC-TM-650 2.3.25 and ion chromatography (IC) in accordance with IPC-TM-650 2.3.28. Other customer-specific standards may also be applied.
ROSE Test
The ROSE Test (Resistivity of Solvent Extract) is a proven method for determining total ionic load. In this process, ionizable residues are extracted from a sample and evaluated based on changes in conductivity/resistivity.
The ROSE test is suitable when…
- a quick overall assessment is needed
- processes are monitored regularly
- limit values or internal standards need to be checked
Ion Chromatography
Ion chromatography (IC) is the method of choice for the detailed analysis of ionic contaminants. Unlike the ROSE test, it not only provides a total value but also identifies and quantifies individual ions.
Ion chromatography is suitable when…
- individual ion species need to be determined
- the causes of contamination need to be narrowed down
- abnormalities identified in a ROSE test, batch, or complaint need to be further investigated
The Right Method for Every Need
| Method | ROSE-Test | Ionic Chromatography |
|---|---|---|
| Results | Total value of total ionic load | Identification and quantification of individual ions (anions, cations, and organic acids) |
| Application | Screening, serial monitoring, process control | Root cause analysis, complaints, detailed evaluation |
| Advantages | Fast, robust, comparable | Comprehensive, detailed analysis; targeted measures are possible |
Components that are particularly critical
in cases of ionic contamination
Ionic residues become particularly critical when tight structures, hard-to-reach areas, moisture, and electrical stress converge. In these areas, even small residual amounts can lead to leakage currents, corrosion, or long-term effects.
Among others, the following are particularly susceptible:
- Components that are difficult to clean and hidden areas
- BGA, CSP, and µBGA with residues beneath the component
- QFNs and LGAs, as areas beneath the package may contain residues
- Fine-pitch ICs and very small passive components such as 0402 and 0201
- THT holes and solder pads with potential capillary effects
- Areas with small trace spacing
- Connectors, contact surfaces, and sensitive connection areas
- High-impedance and high-voltage areas, e.g., in analog front ends or sensor systems
Typical Applications of Ionic Contamination Measurement
Ionic contamination measurements are used to objectively assess the cleanliness of printed circuit boards and electronic assemblies, to validate processes, or to narrow down the causes of anomalies.
Typical applications include:
- Quality assurance in series production, e.g., through sampling and trend monitoring
- Incoming goods inspections and supplier comparisons
- Process approvals following changes to flux, cleaners, or process parameters
- Complaints, damage analyses, and investigations of field returns
- Verification prior to protective coating, conformal coating, or potting
Frequently Asked Questions About Ionic Impurities
Ionic contamination refers to residues on surfaces that can become electrically conductive under certain conditions. In electronics, this primarily affects printed circuit boards, assemblies, solder joints, and component terminals. This contamination becomes particularly critical in the presence of moisture and electrical voltage.
Ionic contaminants can originate from flux, soldering processes, cleaning chemicals, process residues, handling, packaging, storage, or environmental factors. Often, the cause is not immediately apparent and must be identified through analytical testing.
Possible consequences of ionic contamination include corrosion, leakage currents, electrochemical migration, dendrite formation, short circuits, malfunctions, or field failures. Residues can also contribute to adhesion problems with protective varnishes or coatings.
Ionic contamination is measured using test methods such as the ROSE test or ion chromatography. In these methods, residues are removed from the surface of the printed circuit board or assembly and then analyzed. The method used depends on the specific problem at hand.
The ROSE test measures total ionic contamination as a sum value. Ion chromatography provides a more precise analysis: it identifies which ions are present and in what concentrations. The ROSE test is therefore particularly suitable for rapid screening, while ion chromatography is better suited for detailed root-cause analyses.
Ion chromatography is useful when ionic impurities need to be analyzed in greater detail. Unlike the ROSE test, it identifies and quantifies individual ion species, such as anions, cations, or organic acids. This makes it particularly suitable for root cause analyses, customer complaints, unusual measurement results, or technical issues where determining the total concentration alone is insufficient.
The assessment depends on the product, the application, the standard, the specification, and the specific operating conditions. General threshold values are therefore not always sufficient. What matters most is the technical evaluation within the specific technical context.
Using ion chromatography (IC), cations and anions are determined with the aid of standards. This allows even unknown substances to be identified based on their retention time.
As part of our standard ionic contamination analysis, we analyze the following for you:
- Anions (bromide, chloride, fluoride, nitrate, nitrite, phosphate, sulfate)
- Cations (ammonium, calcium, lithium, magnesium, potassium, sodium)
- Organic acids (acetate, adipate, glutamate, malate, methanesulfonate, succinate, phthalate)
Please feel free to contact us for special analyses.
Accredited test laboratory for the analysis of ionic contamination
Identification and quantification of organic and inorganic substances, materials, residues, deposits and contaminants using FT-lR and energy dispersive (EDX) spectroscopy are accredited by Deutsche Akkreditierungsstelle GmbH (DAkkS) in accordance with DIN EN ISO/IEC 17025. Furthermore, all our other specialist areas have also been accredited.
You can read more about the advantages our accreditation offers you here:
Quality Analysis
the right partner for
ionic contamination
Are you looking for a partner for ionic contamination?
We would be pleased to advise you about the analysis options and assist you choosing the proper analysis method. The goal: the best, most cost-effective and most efficient analysis of your component.