Author: Thierry ARZAILLER
Process engineer and industrial manager
SAFRAN Morpho, Saint Etienne du Rouvray (France)
SAFRAN Morpho presentation:
Morpho (Safran) is a global leader in identity and security solutions for an increasingly digital and connected world. We employ more than 8,600 people in 55 countries and generated revenues of more than €1.5 billion in 2014. Backed by more than 40 years of experience in biometrics, our unique expertise lies in developing innovative technologies for a wide range of markets and applications for people, governments and business. Morpho contributes to managing identities, protecting borders, detecting threats, supporting law enforcement and providing trusted on-line transactions and services. Our solutions protect identities, ensure safety and safeguard privacy, for easier, everyday lives. To provide customers with innovative solutions adapted to their needs, we invest heavily in Research and Development. In 2014, 8% of the annual turnover was dedicated to R&D initiatives. About 30 percent of our employees work in R&D centers around the world. Their outstanding expertise and multi-cultural background play an important role in maintaining our technological leadership. Our network of state-of-the-art production plants maintains a high degree of flexibility and responsiveness to meet specific customer needs. We provide an extensive range of services, from design to support and maintenance. Our close relationship with customers helps us anticipate future trends and fuel innovation. Saint-Etienne du Rouvray (France) is the reference plant for new product introduction and manufacturing of terminals and complex systems.
Morpho and the Vi TECHNOLOGY partnership:
The partnership between our two companies started in July 2013, with our decision to be, in Saint-Etienne du Rouvray, a beta site for new products developed by Vi TECHNOLOGY: the new 3-Dimension Solder Paste Inspection system (3D SPI), called PI PRIMO, and the associated software suite, called SIGMA Link, allowing us to do the first move toward Industry 4.0.
Before acquiring PI, we were sampling some PCBs by using the 2D SPI functionality (presence, absence, XY offsets) embedded in our paste printer. Paste height measurement was done using additional off-line equipment. However, this old-fashioned methodology provided limited measurements, compromised our productivity and prevented us from detecting an important defects, like insufficient paste due to clogged stencil apertures or bridging between pads.
Once we installed PI PRIMO, we were immediately seduced by its innovative user interface, allowing any operator regardless of his experience level to quickly use the machine by himself with limited training, and to test his first PCB in less than one day. In addition, we immediately took advantage of PI specificities, i.e. the possibility of grouping pads according to their size and shape. This allowed us to significantly ease the fine-tuning and limits settings for paste volume, height, area, location XY, shape, coplanarity.
Touch-screen user interface from PI:
Picture: Thierry Mamberti / SAFRAN
Finally, this test phase of PI PRIMO was a great success because the production team quickly adopted the technology of very accurate paste volume measurement. This allowed us to detect the majority of our defects and then predicting the end-quality level of our production line.
By using PI PRIMO, we improved our process knowledge by realizing the relationship between the deposited paste volume and the following 3 parameters:
• the Aperture Area Ratio (AAR) characterizing the link between the stencil aperture area and its thickness,
• the speed and pressure of the squeegee,
• the location of support pins, in our paste printer.
Exemple d’un écran de sérigraphie : Example of printer stencil:
Picture: Thierry Mamberti / SAFRAN
From this knowledge, we meticulously scrutinized our stencils by redesigning the aperture dimensions according to AAR and we fine-tuned our print parameters (cleaning frequency, speed and pressure of the squeegee). PI PRIMO allowed us to develop new ways to control our print process and to handle defective PCBs earlier in the production cycle to minimize the associated cost of waste.
Following this positive experience with Vi TECHNOLOGY Solder Paste Inspection system, we acquired their Automated Optical Inspection system (AOI), model “2K”, in order to perform post-reflow component inspection. To reduce programming time for SPI and AOI, we also adopted SIGMA Import, part of the SIGMA Link software suite. This allowed us to work with a single interface for programming files from Gerber, VIS, CAD xy files, and create a unified database required to satisfy our growing needs for traceability.
Today, the average programming time using SIGMA Import is 30 minutes for complex PCBs (dual sided PCB with active components) and 10 minutes for simple PCBs (LED, mux/demux boards…). Once both programming files are generated, we define tolerance settings for PI PRIMO (from 5 to 15 minutes) and finalize AOI programming using Vision 64 embedded software (time depends on new component types on the PCB; for example it takes 30 minutes for a PCB with limited new types).
From the beginning of 2015, we are also evaluating SIGMA Review which allows us to simultaneously review, on a single workstation with all defects detected by SPI and AOI. This allows us to compare them with reference images so as to ease the operator’s decision (pass/fail). This software allows us to validate SPI/AOI correlation, and to better detect and understand defects like tombstoning and paste offset (for example when components are correctly placed, but with slightly shifted solder paste).
SIGMA Review helps us improve our response to defect detection and contingency actions.
At the beginning of 2015, we decided to rely on SIGMA Analysis instead of using statistical tools like Matlab or Minitab for filtering collected process data, and identifying trends. This offers advanced Statistical Process Control capabilities which allows technician-level workers to perform adequate data mining from SPI/AOI. This in turn enables needed analysis to quickly identify the root-cause of any defect with associated corrective actions. The traceability offered by SIGMA Import, together with SIGMA Analysis capabilities, are key contributors of our continuous improvement strategy, which allows us to clarify major Key Performance Indicators (KPI):
• top 10 defects
• defect location on each PCB
• 3D defect image
• real-time monitoring (line performance)
• Cp / Cpk and various detailed Pareto and pie charts
SIGMA Analysis is also very convenient to correctly manage in the qualification phase of new processes. It helps in immediately characterizing the effects due to such things as new solder paste introduction, or comparing individual influences of process changes.
SIGMA Analysis is the needed software to simplify any new process introduction, and to significantly reduce implementation time.
SIGMA Analysis (for SPI):
Thanks to PI PRIMO (SPI), 2K (AOI) and SIGMA Link (Process Improvement Software Suite), the Vi TECHNOLOGY solution allows us to quickly detect each defect, to understand its root-cause and to take appropriate corrective actions at the lowest cost.
Vi TECHNOLOGY has contributed to significantly improving the quality of our production line.
The continuous improvement strategy deployed on our production line, for the past 18 months, has allowed us to reduce our end-of-line defect level from 120 to 80 ppm.