Users Stray from Profiling Verification
A survey of people involved with PCB soldering that was begun at the Assembly Process Expo in March and continued through April has yielded a surprising result about thermal processing practices. While 90 percent of survey participants showed diligence in creating a process profile, 60 percent say they do not verify it on a regular basis.
Respondents who do not verify their process profiles say the reasons are difficulty and/or time required. The survey was developed and conducted by ECD Inc., Milwaukie, Ore., a profiler equipment manufacturer.
According to ECD, the firm has addressed the issue of nonverification on three levels with its M.O.L.E. system.
First, the V-M.O.L.E. thermal profiler cuts production time, using only three thermocouples to verify previously established profiles. This method, when using correct parameters, has been established as effective by a study at Binghamton University in New York. (The study is available at www.ecd.com.)
According to the manufacturer, the V-M.O.L.E. system does not require operators to have prior profiling knowledge. Containing an “OK” button, it gives a clear “Go/No-Go” signal so the operator does not have to involve the engineer to okay a run, which helps maximize production throughput and ensure quality.
Second, ECD encourages profile verification of successive runs by simplifying thermocouple attachment. Attaching thermocouples is one of the most commonly reported barriers to consistent thermal profiling, according to ECD. The AttachEz thermocouples are compatible with lead-free profiling temperatures, fast to attach, stick well to flat or curved surfaces, can be reused, and provide number identification.
Third, continued verification of the profile throughout successive runs assumes added significance in light of the newly released J-STD-075 standard. Showing degradation of thermally sensitive passive components during reflow to be one of the main causes of product field failure, the standard concludes that such degradation often is not picked up by traditional assembly tests and inspections. Instead, degradation often appears years later, after the product is in the user’s hands. Profiling remains key to preventing both degradation of components and field failure of the product.
The ECD survey was conducted in print and online, and respondents at APEX were eligible for a drawing for a free profiling kit.