Issue link: https://iconnect007.uberflip.com/i/1424540
70 SMT007 MAGAZINE I NOVEMBER 2021 ceptable residues on electronic assemblies and the effects of the residues, and to address both clean and no-clean electronics. is SME team (or A-Team) met two to three times a month over the course of three years, resulting in the approach published in J-STD-001, Revision G, Amendment 1. Because this was such a dramat- ic change from what manufacturers were used to, the Rhino team also generated a detailed white paper, explaining the changes. IPC-WP- 019A was the resulting document. When IPC- J-STD-001 went to Revision H, WP-019 (Rev B) was also revised to keep the language cur- rent. In addition, several members of the Rhi- no team have hosted half-day and full-day pro- fessional development (PD) course to help people understand the changes. Most of the information included in the overhaul are a reaffirmation of Chapter 3, "Ma- terials, Components and Equipment Require- ments," but also addressed many questions that were not addressed in previous revisions of the standard, such as: What requalification is needed for a change in materials or process- es? What is a major change, what is a minor change? How is no-clean manufacturing ad- dressed in a section focused on cleaning? e single biggest change in the new proto- col is that prior to the new protocol, the use of the Resistivity of Solvent Extract (ROSE) test was used as the arbiter between acceptably clean and unacceptably dirty, using a metric of 1.56 micrograms of sodium chloride equiv- alence per square centimeter. e new pro- tocols declared that test as an obsolete prac- tice for determining acceptably clean or unac- ceptably dirty but could still be used for pro- cess control. It was recognized that replacing ROSE for product acceptance with another test would likely be a long process. Some of the confusion comes from what is in the white paper and what is in the re- leased revision H. e approval of J-STD-001 G Amendment 1 was supported by WP-019A, and J-STD-001 H was supported by WP-019B. One thing missing from the new cleaning section is, "For assemblies soldered with ROL0 or ROL1 fluxes and tested by Static Extraction Method, contamination shall [D1D2D3] (De- fect all classes) be less than 1.56 micrograms/ cm 2 sodium chloride (NaCl) equivalent ion- ic or ionizable flux residue." at number is no longer there. I thought it was an odd num- ber (even though it's an even number) but most of that has to do with its Imperial Eng- lish equivalent: 10 micrograms/in 2 . at's the number I remember the requirement as be- ing. Most people mention that it has been in use as long as they have been in electronics, so for me that would be the late 1970s. Also, I re- ally didn't worry about cleaning requirements at that time for a few reasons. First, I wasn't a process control engineer, I was an assembler. Also, we used high solid rosin fluxes and a va- por degreaser with a great fluorocarbon clean- er. Our assemblies also had very large electrical clearances. We hadn't heard of surface mount components at that time. e vapor degreaser worked great; I was sad to hear it was depleting the ozone and we had to get rid of it. I just recently implemented the 3 Sigma test methodology based on empirical data of ac- ceptable hardware. at upper control limit (UCL) that we came up with was significantly less than the old requirement. I was concerned with the change at first but if your process is in control then you will pass the test 99.73% of the time (at least that's what I told our lead polymerics technician). What we had feared Several members of the Rhino team have hosted half-day and full-day professional development (PD) course to help people understand the changes.