About Ionic Cleanliness Testing

Numerous Printed Wiring Board (PCB) and Assembly (PWA) failures that occur in the field can be attributed to manufacturing and/or assembly process residue that were not properly removed from the end-product. It is essential that the cleaning process be monitored to ensure proper removal of contaminants that may, when exposed over time, temperature, and humidity, lead to higher failure rates.

The Ionic cleanliness test(s) are utilized to measure the conductivity or Resistivity of Solvent Extract (ROSE) of a PCB/PCBA which can be directly correlated to the amount of ionic materials present on the sample. These tests are commonly used as process control tools. However, they are primarily used to inspect printed wiring boards or printed wiring assemblies to determine if they conform to the monitoring level of the user’s performance specification. Ionic Cleanliness Testing may be accomplished by measuring the ionizable surface contaminants extracted by the following three methods:

Numerous Printed Wiring Board (PCB) and Assembly (PWA) failures that occur in the field can be attributed to manufacturing and/or assembly process residue that were not properly removed from the end-product. It is essential that the cleaning process be monitored to ensure proper removal of contaminants that may, when exposed over time, temperature, and humidity, lead to higher failure rates.

The Ionic cleanliness test(s) are utilized to measure the conductivity or Resistivity of Solvent Extract (ROSE) of a PCB/PCBA which can be directly correlated to the amount of ionic materials present on the sample. These tests are commonly used as process control tools. However, they are primarily used to inspect printed wiring boards or printed wiring assemblies to determine if they conform to the monitoring level of the user’s performance specification. Ionic Cleanliness Testing may be accomplished by measuring the ionizable surface contaminants extracted by the following three methods:

The resistivity of the solution will decrease as the amount of ionic contamination increases. There are two types of contaminants – Ionic and Non-Ionic. Ionic contaminants are typically flux residues or other harmful materials that are encountered during the manufacturing process and may remain as the result of insufficient final cleaning. These contaminates are normally water-soluble organic or inorganic acids or salt residues. They contain molecules that are conductive when in solution that can separate into positively or negatively charged ions and increase the overall conductivity of the solution. These ionic contaminants may then degrade the reliability of the electronic components and/or assemblies as they contribute to current leakage between the circuitry and could promote dendritic growth, increasing the danger of corrosion.

References

Detection and Measurement of Ionizable Surface Contaminants by Resistivity of Solvent Extract (ROSE)

Ionic Analysis of Circuit Boards by Ion Chromatography

    • IPC/EIA J-STD-001
      Requirements for Soldered Electrical and Electronic Assemblies
    • IPC-TP-1113

Circuit Board Ionic Cleanliness Measurement: What Does It Tell Us?

    • IPC-5702

Guidelines for OEMs in Determining Acceptable Levels of Cleanliness of Unpopulated Printed Boards

    • IPC-TR-583

AN IN-DEPTH LOOK AT IONIC CLEANLINESS TESTING

    • IPC-HDBK-001

Handbook and Guide to Supplement J-STD-001

  • Manual Extraction Method
  • Dynamic extraction method (Most-efficient and Highest-level of Accuracy)
  • Static Extraction Method

QUICK CONTACT