Any sales professional operating in the inspection space will tell you that the market is flooded with competition when it comes to solder paste inspection (SPI) and automated optical inspection (AOI) machines. Although I have no doubt their preferred solution will be the market leader, unless you are knowledgeable about the differences in provider and the array of technologies available today, you can soon fall into a trap of not selecting the correct platform for your application.
This column has previously addressed the differences between 2D and 3D optical and 3D light measurement (gold standard). However, the key element of R&D for the handful of top inspection companies is the software that accompanies the hardware they supply. The ultimate aim is for automatic process improvement and adjustment of processes by inspection machines in the line in real time. Before I jump into what is possible, I first want to explain the “why” and the current situation for many companies.
Increase in Inspection Equipment
The rise in inspection systems was originally positioned as a form of safety net to capture PCBS, not matching a comparative gold-standard product. Escapes and faults from production can be caught before they get to the customer and damage credibility, which would eventually affect company profits. Intelligent companies invested in SPI because 84% of production faults are caused by solder errors. However, more companies invested in AOI as a fault finder once the board had been populated.
Hardware has moved on, computing power has grown exponentially, and the number of sensors in inspection machines has matched this growth in computing power. This has resulted in more accurate machines with the ability to collect more data. In turn, this has culminated in detailed information now available to judge if the board is of a satisfactory standard based on the gold-standard board/programme.
Most agree that this is great, and besides the false call problems in 2D systems, I believe many readers would say that modern, real 3D systems have solved lots of those issues. The key to the next step in automated adjustment is the accuracy and repeatability of measurement. One company that is trailblazing this ideal is Koh Young. Since the Koh Young system uses light measurement, it produces the most accurate measurements of a PCB; therefore, it can be used to set the tightest tolerances. This results in better quality inspection, PCBAs, and a large reduction in false calls.
Data Collection: Adding Value
In a world of IoT communication and data collection, it was obvious that the only path for AOI and SPI was to capitalise on the data collection, repurposing the content into a deliverable that can add value to the end customer. Based on this fact, the key direction of inspection companies was to invest heavily in software and graphical user interface (GUI) to translate the content. Investment in the development of AI capabilities and machine learning for statistical analysis was also key. The aim of this investment was to create a platform, allowing end users to use real-time data from their production. Using software and algorithms to analyse the content resulted in informed process improvement decisions and enhanced upstream and downstream processes.
So, what do we have now? I will concentrate on what I know well from Koh Young; however, I have no doubt that the other top providers will be developing or have developed their own software capabilities (some better or worse than others). Koh Young has developed KSMART, which is a modular-based software solution that allows customers to access content sets through their GUI. The modular nature allows users to pick and choose what information can be seen so that the package is tailored to information benefitting specific requirements. I want to pull out one element of the software that is related to SPI because it is a good example of a module achieving the desired result (i.e., using an inspection system to automatically correct and improve upstream/downstream processes).
Let’s look at the KSMART Process Optimiser (KPO), which is a module designed specifically for SPIs and solder printers. This module takes an SPI system in connection with a configured screen printer to take real-time inspection information and form an automated feedback loop to improve the printing programme. This then improves the printing performance of the printer and the quality of the product being assembled. This SPI unit has moved from letting the operator know if the results are good or bad into evaluating the good board information further and recommending improvements to the upstream processes to make them even better. This has a direct impact on improving the production and quality of the good boards to make them of a superior standard. This innovative software is already installed on production lines globally.
Software of Dreams
More broadly, this is a process engineers dream of and is now a reality. Before, if there was a problem on a PCB—such as a component of difficulty—decisions were made from an engineer’s knowledgeable eye and adjustments made drawn from previous experience. Engineers were required to monitor and continuously adjust parameters to address any problems, such as adding more solder past or changing the reflow profile.
Now, process engineers can recall large data sets at different stages of production through the information received from the inspection stages (SPI, pre-reflow AOI, and post-reflow AOI) to come to a data-driven decision. They can monitor their actions closely across all processes, whilst in certain areas, machine-to-machine communication can lead to increased performance without any human intervention.
Further, what is not currently available, is the communication and automatic influence of other elements of the line; for example, pick-and-place and reflow to the AOI would perhaps be a good place to find a solution. For that to happen, it is key that suppliers work to the same communication standards, such as Hermes so that manufacturers can communicate freely regardless of the unit they have in each process.
As companies focus on CFX, the standard being developed by the electronics manufacturing industry, and packaging analytical products to drive Industry 4.0, I only see this ability to draw out data and analyse it becoming larger and more prominent in electronics manufacturing. I look forward to seeing further releases of software and new capabilities at the productronica show at the end of this year. But for now, there is a huge gap between the technology that is available and the way the market is utilising it to their advantage.
Joe Booth is business development and marketing manager at Altus Group Ltd.