The Importance of Accurate Inspection & Measurement on Panasonic’s PCBs
Panasonic Communications Company Ltd is taking a leading role developing a range of PBX telecommunication systems for the rapidly expanding global market. To continue producing high quality products that meet with so many regulations including both quality and environmental conditions, Panasonic utilise Vision Engineering’s Lynx stereo zoom microscope for optical inspection and measurement of Printed Circuit Boards (PCBs).
Panasonic Communications Company UK Ltd manufacture Digital Telecommunications products at their site in Newport, South Wales and over the years have implemented a number of management systems such as ISO: 9002 and ISO: 14001, with a large emphasis on sustainable waste management.
These management systems have been applied to refine manufacturing processes in relation to both quality and waste in accordance with RoHS and WEEE directives. Refining these processes for quality control and in addition to the restrictions in manufacturing PCBs with lead-free solder, results in the need to produce products manufactured to precision. To consistently achieve this, Panasonic have employed accurate equipment like the Lynx stereo inspection system in the monitoring of initial runs in their automated PCB assembly lines.
An example of one on the telephone systems that is manufactured at the Newport site is the Hybrid IP PBX System or KX-TDA 600 providing up to an impressive 960 extensions. The KX-TDA includes features that provide the optimisation of numerous communication requirements simultaneously, including hospitality, call centres, remote users and IP networking. The PCB required for this PBX system requires the technical expertise of the engineers to deliver rapid turnaround times, with the supply chain, logistics and warehousing of component parts kept to a minimum - with only a maximum of one day of stock at any one time. With the responsibility of supplying all of Europe, in addition to the rapid turnaround time, the engineers at Panasonic are required to produce a range of PCBs (for their PBX systems) assembled to extremely high specifications and within tight tolerances. For example, the first stage of a new run would require the engineers working on the production line to fine tune the pitch of the tracks on the boards within 25µm. They achieve this by using the Lynx to measure the pitch after the first board has been printed from the stencil at the first stage of assembly. The pitch of the paste is measured using graticules within the optical viewing head. The high contrast images allow the operator to precisely align the pitch with up to x120 magnification.
Panasonic have benefited from using a high performance charged-coupled device (CCD) system to digitally capture the image of the pitch allowing for further image manipulation, reporting and measuring capabilities. If the pitch of the tracks is not monitored and measured at the beginning of the run and the whole batch is printed incorrectly, this could result in a costly production error.
The SMT lines run at the site in Newport require the technical knowledge and experience from senior engineers to coordinate and maintain. Alan J. Jones, Process Engineer of the Panasert Engineering Department is part of a team having the responsibility of maintaining each line. Alan explains the importance of the use of lynx within the assembly of the PCBs.
“Although we were one of the first companies to embrace the use of lead free solder, there are many important factors that have to be considered including the extent to which the lead free solder reflows. When we were using lead solder there was an element of flexibility, but with the restricted reflow of lead-free solder, we have had to adjust our processes implementing procedures that consistently lead us to assembling extremely accurate boards. Ultimately, if we can achieve exacting pitches across the boards, within 25µm, we can be confident that the alignment will be repeated across the whole batch. We do this by aligning the pitch under the Lynx and a CCD”.
After the boards have gone through the final process of reflow, they are delivered to Main Line where they are meticulously tested before the PBX systems are fully assembled. The PCBs are 100% inspected for any imperfections before they proceed any further. At this stage, the Lynx is also used to inspect any suspicious joints or components that require further investigation. For example, the Lynx can magnify the image of any particular component, whereupon if there is a misalignment with a component and the pads, Lynx can capture the image which will provide a starting point for investigating the stages at which the misalignment may have occurred. The Lynx features either a direct or a 34° angled view oblique mode allowing a full 360° view rotation around the centre point.
Alan also explains how important the Lynx is to the Panasert Engineering Department in addition to other departments across the site at Newport.
“Since we have invested in the Lynx we have found that it has paid for itself many times over. Initially we were using it to measure the pitch on the various PCBs we produce, but over the years it has been utilised extensively across the whole site”. Alan D Griffiths, Quality Technician in Panasert explains how the Lynx has been used for quality issues.
“The Lynx is literally used 24/7 and in a number of departments for a wide range of measurement and inspection tasks. We use it extensively in the Quality Control department, mainly for magnifying the boards so that we can see the different components and the joints etc. If there is something we need to communicate back to design, we can capture the area in question and send it electronically. This will enable us to get answers quickly, optimising our time and the turnaround time of a run”.
With Panasonic’s innovative range of state-of-the-art telecommunication systems developing and expanding, Panasonic have taken the steps to invest in seamless production processes and the tools required to implement them successfully, maximising both quality and efficiency. With quality expectations running high for Panasonic’s products and increasing pressures from quality and environmental standards, Panasonic have succeeded in consistently leading the way, irrespective of these challenging manufacturing factors. |
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