Circuitwise has installed two new reflow ovens, believed to be the most advanced in Australia. Reflow ovens are used for the reflow soldering of electronic components onto printed circuit boards, creating a printed circuit board assembly.
Circuitwise had undertaken this investment in cutting edge technology because of the trend in electronic design to pack more and more components into a smaller space, often with more sensitive specialised components that must be managed individually in the process and an increasing number of in-board circuitry layers. Electronics for these devices require tighter control of the soldering process, with time/temperature profiles customized to each PCB.
The new reflow ovens from JT Technologies have ten zones, allowing for better control and optimisation of heating and cooling, delivering a thermal profile that is customed to each PCBA.
Features of the proposed new technology include lower temperature deviation between components, smaller zones of temperature control, larger temperature difference between adjacent zones, better closed-loop control and rapid thermal compensation to reduce temperature fluctuations.
Measuring 6.3m in length and weighing 2700kg, the ovens are the largest pieces of equipment on our factory floor. It is powered by a 3 phase 380V feed with a total power rating of 80kV and power consumption of 10KW.
The greater control will allow Circuitwise to make better use of its custom reflow profiling process. In this process, we take the first board produced, or a sample supplied by the customer, and rig it with sensors attached to areas of significant thermal mass. This is run through the reflow oven to monitor the effects of the different heating zones on the PCB assembly's components.
A computer algorithm then calculates the optimal profile for temperatures and dwell time in each part of the oven. In some cases, it takes many hours to make this profile - which matches the solder paste specifications to the thermal density of the PCB. This data is used to program the oven and the board's profile is then saved for future runs of that product.
This technology is enabling a step-change in the complexity of PCBAs that Circuitwise can manufacture, In particular, it will allow us to accommodate the increasingly sensitive custom sensors/components being used in many innovative devices, particularly in the growing market of medical devices.
Designers of medical devices must reduce safety risks “as far as possible”, including the risks involved in manufacturing devices with electronics and software, requiring a higher level of process control and testing regimes. This advanced technology facilitates greater process control.
Medical devices are increasingly using Internet of Things technologies, miniaturising and compressing the electronic componentry onto ever smaller boards in more compact casings. This is increasing the demands on the process controls required to prevent shorts and tombstoning arising from increased component density.
Along with our advanced testing equipment and processes, Circuitwise can ensure that all devices shipped are manufactured in a controlled environment, inspected and tested “as far as possible” to ensure that the devices are safe and functioning as intended before being shipped to therapists for use on patients.
Thanks to the Australian Government which supported this project via a grant in Round Two of the Manufacturing Modernisation Fund.