EIPC 50th Anniversary Conference Day 1: The Past, the Present and the Future, Pt. 1

Estimated reading time: 16 minutes

As I-Connect007 technical editor and a technical consultant to EIPC, I was delighted to be invited to moderate the third conference session, on the theme of safety, process reliability and traceability in automotive PCBs. 

My first speaker was Frank Tinnefeld, joint managing director of ASS-SAA Automation, on the subject of fully integrated PCB production automation. His presentation referred specifically to the latest status of the new Unimicron factory in Geldern, for which his company had provided the automation and handling systems.

After the fire in December 2016 which destroyed their innerlayer plant, Unimicron moved quickly to specify its replacement in cooperation with ASS Luipold and SAA, who were later to merge their product portfolios as ASS-SAA Automation. The target definition was clear: the newest art of technology, to be prepared for future market requirements, with lead-time reduction by in-line production automation wherever it was useful, automation of all production processes, 100% order tracking and the elimination of manual order input and accompanying paperwork wherever possible.

The production concept was to cluster innerlayer manufacture: in-line from loading the pre-clean to unloading the develop-etch-strip line, AOI, then in-line from loading the innerlayer punch to unloading the bonding-treatment line, then multilayer lay-up and lamination followed by outer-layer X-ray and multilayer edge trimming, before proceeding to outer-layer production.

The equipment concept was realised by the integration of smart work-in-process storage solutions, first-in-first-out buffers and automatic guided vehicles carrying the work between develop-etch-strip and AOI, between AOI and innerlayer punching and bonding treatment, and between bonding treatment and multilayer lay-up. This enabled automated process load-unload without interruption of production in the case of a change of material, with double pallet automation, double cassette automation and double pallet interleave handling.

Every single panel was marked with a unique data matrix code (DMC) to enable 100% panel tracking through the entire process and every work-in-progress cassette was tracked via its barcode and its contents were always identified. And the intelligent manufacturing execution system integrated smoothly with the customers’ ERP and quality systems.

Tinnefeld’s presentation was an exemplary demonstration of the PCB 4.0 smart factory concept and provided a meaningful introduction and background to the Unimicron visit which followed at the end of the conference day.

A further example of automation and traceability in Smart manufacturing was provided by Jochen Zeller, vice-president and co-founder of AWP Group, suppliers of material handling and automation systems and horizontal wet processing equipment, who took as his model the Industry 4.0 factory integration project at Whelen Engineering’s GreenSource PCB fabrication plant in Charlestown, New Hampshire, USA.

The project mission had been to create a fully automated, integrated and data-driven PCB factory, realising a true single-piece flow. Zeller demonstrated how the automation and integration concept had been achieved using the example of the innerlayer cell. He described the features of key equipment, with specific reference to a flexible robot system capable of the gentle handling of ultra-thin material with contactless centering, which utilised a 6-tray transport cart with individual access to each tray based on data input from the MES system. Trays were loaded automatically into the machine in random order and each tray was equipped with an RFID chip, as was the cart itself. Five of these robot units were employed in the innerlayer cell.

The second piece of key equipment he described was a flexible buffer which controlled how many panels were in the entire system to ensure all the panels could be stored in a fault situation. The buffer system used pick-and-place, rather than belts, for particle-free operation and was fully flexible to compensate for different line speeds in an interconnected system. Three of these buffers were used in the innerlayer cell.

Each panel had a unique DMC code, and DMC readers were positioned at every stage of the process. If, for example, a program change was required on-the-fly at the etching machine to compensate for different copper thicknesses, all the spray bars were individually controlled, and the change would be initiated based on the data input from the DMC code on that panel. Additionally, there were RFID read-write heads and connection modules at several stages in the innerlayer cell to track carts and trays. The project mission had been achieved and the fully-automated, integrated and data driven PCB factory, with single-panel flow, had been realised.

Recently returned to Europe after a few years in the USA and China, we welcomed back former EIPC vice president Giacomo Angeloni, product realisation director with Mektec Europe. Being a football fan, he could not resist a dig at the England team’s chances in the World Cup competition in Russia, with a cartoon of their bus parked on the short-stay at Heathrow!

To more serious matters, he gave an enlightening presentation on safety in connecting technology for battery cells in EV cars. He explained that Mektec Europe is a major supplier of flexible circuits, assemblies and modules to the automotive industry, and that flexible circuits were at the crossroads of innovation in the automotive market.

Fires had been associated with lithium batteries in several high-profile incidents, notably with Boeing, Samsung and Tesla, but in the automotive examples only a very small proportion of highway fire accidents could be attributable to lithium batteries and then the problems had typically been related to overcharging or mechanical abuse. But there was still plenty of scope for improvement in some of the techniques used to interconnect the cells within the battery, to simplify the connection, avoid the possibility of short circuits, and accommodate dimensional changes during charging and discharging. Flexible circuit techniques offered reliable and cost-effective solutions. Connection could be made by riveting or ultrasonic bonding, and fuses and over-temperature sensors could be incorporated. He showed several examples of non-safe and safe connections and passed round several hand samples. Typical base materials were 2-mil polyethylene naphthenate, and 2-mil or 1-mil polyimide.

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