Indium Blog

Classifying Fluxes Under The New IPC J-STD-004B

  • Flux
  • Indium Corporation

  • The current version of IPC J-STD-004 is revision B, often referred to as J-STD-004B. Interestingly, all previous revisions remain useable. Let’s explore this interesting situation.

    IPC J-STD-004B directs: "Although the requirements of J-STD-004 have changed with each revision, fluxes that were classified to earlier revisions of IPC J-STD-004 do not require reclassification. Anywhere the J-STD-004 classification is documented for a particular product, the revision level of J-STD-004 to which the product was classified shall be included."

    These instructions are clear. Let’s develop a couple of scenarios to depict how fluxes should be labeled, and how we should refer to these products:


    • Your flux did satisfy a pre-B version of the standard, version A.
    • Your pre-B flux was not re-classified successfully under Rev B.

    It must be referred to as meeting J-STD-004A. It cannot be referred to as meeting 004B, nor can it be implied to have been “grandfathered” in – there is no such thing.


    • Your flux did satisfy a pre-B version of the standard, version A.
    • Your pre-B flux was re-classified successfully under Rev B.

    Your flux can be labeled as meeting J-STD-004B.


    As stewards of our processes, our companies reputations, and our technological integrity, it is our job to assure not only compliance with, but ethical treatment of, this new standard. The IPC isn’t telling us which flux to use, or even which standard to use. It is directing us as to how to properly label and refer to them. Based on the IPC directive, a flux is either compliant with a pre-B standard, a B standard, or neither. There is no “grandfathering”.

    Now is a good time to affirm the status of the fluxes in your process. Speak candidly and frankly with your vendors to affirm that everyone is crystal clear with your needs, expectations, and requirements, and with the letter of the law. An accurate and effective conversation today can eliminate a possible embarrassing, even damaging, conversation in the future.

    If you have any questions, or want to clarify your situation, feel free to contact me.