Shining light into a dark zone, bringing reflow to the next level

Davina McDonnell Press

Originally published in SMT Today.

When we installed KIC’s smart oven technologies earlier this year, everyone at Saline Lectronics was incredibly enthusiastic. With these systems, we would finally get full visibility inside the “blackbox” of PCB assembly – the reflow oven! No longer relying on a single profile board and spot checks, we are now able to measure and track the exact time and temperature profile that every single PCBA experiences during reflow.

This continuous process verification provides peace of mind to both our customers and electronic manufacturing team alike; as our Manufacturing Manager, Jason Sciberras put it, “KIC’s tools let me sleep better at night.”

Smart Oven Technology - PCB AssemblyPreviously considered a type of dark zone in circuit board manufacturing, the oven has long been a suspicious piece of equipment. KIC‘s smart oven technologies shine a spotlight within our ovens providing full visibility to what’s happening to each circuit board as it moves through reflow.

Tracked by serial number, we are able to provide our customers with profile information for every circuit board assembly. In the event of a failure, this process traceability data becomes invaluable. With proof that the profile is in spec, Engineers can quickly rule out any oven or reflow issues in order to better identify true root cause.

Thorlabs, a customer of Lectronics, recently encountered a failure on a new product design, and initially suspected it was a fault from the reflow process. When they contacted their Account Manager to explain the issue and communicate their suspicions about extreme temperature exposure during reflow, they were pleasantly surprised to receive documentation verifying that every PCBA was reflowed within spec.

“During the beta development phase, one of our products was exhibiting intermittent issues, and originally we thought that they might be the result of hardware faults stemming from extreme temperature exposure during the solder reflow process,” commented Patrick Caputo, Senior Photonics Engineer at Thorlabs.  “Lectronics was able to supply oven temperature profile information for each board, which allowed us to rule out that concern and quickly arrive at the true root cause, which was software related.”

PWI - Process Window IndicatorAs many other OEMs can attest to, this added quality control and enhanced visibility to the oven profiling process is paramount as it provides added security that the process is staying within control. These tools basically function as the “eyes and ears” for our customers giving them added assurance that their products are being manufactured correctly.

Beyond enhanced visibility to what is actually happening to the PCBAs within the oven, we’ve also been able to better qualify PCB profiles with the Process Window Indicator (PWI) tool. The PWI tool measures how well the profile fits the process window and characterizes this relationship into a single number for simplicity and ease of use. Think of this number as Richter Scale of the process.

This PWI tool characterizes each profile in terms of how close it is to the center of the process window, automatically ranking alternative profiles, and immediately providing the ideal oven setup.

Before implementing KIC’s PWI, we relied on our Lead SMT Engineer to create and validate the oven profile for each product. With PWI, more technicians are able to take on this responsibility because the software is automatically monitoring the perfect profile. This not only saves a lot of time during production, but it also creates a better understanding of the overall oven process for many of our technicians. With an increased understanding, and buy-in, of what it takes to optimize an oven profile, we’ve seen an increased drive from our technicians to share ideas on how to potentially improve the assembly process.

Additionally, by constantly measuring and displaying the PWI for each PCBA, we are able to validate that it is staying within spec. In essence, PWI removes the subjectivity from creating oven profiles and offers clear, precise data that the thermal process is accurate.

As part of Lectronics Connected Factory, we are optimizing our entire electronic manufacturing process, and all of our production machines, to create a connected, intelligent and transparent electronic assembly plant. With these smart oven technology tools, we’re able to add the reflow ovens to the Connected Factory and leverage the data from these systems to better improve the manufacturing experience for our customer’s products. And in electronic contract manufacturing, that’s what it’s all about – keeping our customers happy.