Circuits Assembly - March 2008 - (Page 64)

Test and Inspection Implementing AOI Successfully The data are useful, but at times overwhelming. Here’s how to cut them to size. ach AOI or SPI model offers Table 1. Sample Inspection Use Models, By Application different advantages such as Product Type Use Model Reason inspection coverage, speed, Automotive Customer elected to Customer required this save a picture of every level of liability protection programming time, vendor supcomponent on the in case boards were damaged port or cost. However, general use board after reflow. during final assembly, which models are consistent: Each perThe images are saved was performed at a different facility. on a server by serial number. forms user-defined inspections of Consumer Goods Customer and vendorWith the large amount of data a board and provides lists of suscreated software to produced during AOI, it is pected defects and data for each delete certain data important to “clean” information component inspected. Depending after a fixed time that is not relevant for period while archiving manufacturing or quality requirements. on the implementation strategy other information for Understanding the field failure – SPI (3-D or 2-D), pre-reflow, longer periods of time. rates allows users to delete mixed mode, post-reflow, or information after a period. post-wave/final assembly – there Telecommunications Storing component text Many customers store and images for long-term component text, but storing is ample information available liability purposes. Data are images and text removes to the user. Again, depending on stored by serial number any question of misreads the implementation, there will be for easy retrieval. or characters that may not be 100% readable. inherent differences in the data SPI customer kept volumetric Keeping the data available and their usefulness. Certain data Automotive data for every deposit for access by other will be more applicable for differinspected until the board manufacturing and test ent users, but determining what is cleared final assembly and engineers allows them the data were deemed to use the information available, where and for how long no longer necessary. for reports, defect validation and is important to inspection success. long-term monitoring of AOI and SPI generally provide process variables. measurement data, defect calls and defect images. All this is important, but how can a user before machines are moved inline and what can occur quantify and use the information efficiently? How after the fact. long should data be stored? What information should Next, sit down with your vendor and determine be readily available and what should be archived or available data, how long they are stored, and available removed? A post-reflow AOI system can generate offformat(s). The vendor will probably have standard set, presence scores, joint measurements and additional formats available but may have several other options component data for every device on the board. On a if they understand your goals and needs. Images may laptop assembly, this could result in 40,000 data points be stored locally on the system, but scripts or configufor every board inspected. For manufacturers running rations may need to be deleted or images moved to three shifts, that means nearly 200 million data points a defined locations. day! Should all these data need to be archived infiniteThird, ensure everyone follows through on and ly? Should operators be shown every SPC chart known executes the plans. If the goal is to use AOI to improve to man? How long are images of the defects useful? the process, the relevant information must be proWhen implementing AOI, certain key steps need vided to manufacturing in real-time so that potential to take place. issues can be corrected quickly. If the goal is for First, there should be internal meetings with all liability purposes and customer reports, it’s important levels of users to determine the facility needs. Operato determine what data need be kept and for how tors and technicians should be involved in the brainlong. Backup strategies and accessing the information storming sessions, along with engineers and managshould also be at the top of the list. ers, to discuss all variations of needs and practical Finally, consider other test and measurement implementation. Important points to be considered equipment in your production facility. How can the include data storage capacity, customer requirements, data be used to improve processes or better mold your liability, factory software databases, and how each overall manufacturing and test strategies (Table 1)? group would like the data presented. A prioritized list Some of the pitfalls users should try to avoid of the needs is important for the manufacturer and include not involving operators/technicians in the vendor, as this will help determine what is required discussion. These individuals are the front line in E Jeff Bishop is product marketing engineer at Agilent Technologies (agilent.com) 64 Circuits Assembly MARCH 2008 circuitsassembly.com http://agilent.com http://circuitsassembly.com

Table of Contents Feed for the Digital Edition of Circuits Assembly - March 2008

Circuits Assembly - March 2008 Caveat Lector Letters Industry News Market Watch Talking Heads Focus on Business On the Forefront Screen Printing What Drives the Crowd? Mastering ESD Control in Automated Handling Systems Beating the RoHS Heat Trade Secrets True to Its Roots The Road Abroad - Strategic Alliance or Greenfield Facility? Tech Tips Wave Soldering Test and Inspection Process Doctor Pb-Free Lessons Learned Getting Lean Materials World Equipment Advances Apex Product Preview Ad Index Assembly Insider Technical Abstracts

Circuits Assembly - March 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.