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56 SMT007 MAGAZINE I JULY 2021 Feature Article by Debora Obitz IPC IPC-WP-019, "An Overview on Global Change in Ionic Cleanliness Requirements," was initially released in August 2017. is doc- ument, a white paper, was released to help the industry understand new cleanliness require- ments in the G revision of IPC J-STD-001 Requirements for Soldered Electrical and Electronic Assemblies. Leading up to that time, for many years, vast facets of the industry utilized a requirement of 1.56 µg/cm 2 NaCl to determine accept- able cleanliness of printed circuit assemblies. is was conducted using Resistivity of Sol- vent Extract (ROSE) testing per IPC-TM-650, method 2.3.25. With the complexity of assemblies increas- ing and flux chemistries and cleaning solu- tions changing, the ROSE test—originally developed in the 1970s as a process control method for rosin-based fluxes—was not an adequate test for acceptable levels of ionic res- idues on the majority of the new flux chemis- IPC-WP-019: The How-to Behind the Cleanliness Requirements in IPC J-STD-001G tries. Many datasheets indicate that the new flux chemistries cannot be brought into solu- tion with alcohol or water. e ROSE test is based on spraying/immersing the board into a 75% alcohol/25% deionized water solution. From this information, science tells us that the ROSE test is inadequate in these situa- tions. A different method or combination of meth- ods for establishing cleanliness of an assem- bly is needed to provide "objective evidence." at knowledge and understanding led to a small group of dedicated volunteers who named themselves the "Rhino Team" to look at the requirements of IPC J-STD-001 and make recommendations for change. is team included technical subject matter experts from aerospace, materials, automotive, and commercial companies. Over the course of several years and presen- tations to the IPC J-STD-001 task group, new cleanliness requirements were beginning to emerge. e task group determined that a qual- ified manufacturing process was required for manufacturers of Class 2 and Class 3 products.

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