Process validation and standards compliance
becoming more and more important that companies have the latest systems in place to help insure that they can fully validate their manufacturing processes. Having such systems in place can greatly aid in helping a company to get certified as being compliant to a number of industry stan- dards, and, when implemented well, can ensure high marks are received aſter a cus- tomer process audit. Tis article will out- line a number of areas in which the latest manufacturing execution systems (MES) systems, which are designed specifically for the electronics manufacturing industry, can aid in validating key manufacturing processes providing an infrastructure ideal for maintaining compliance with both industry standards and customer expecta- tions.
The MPD and build record When discussing process validation, we find it useful to refer to a couple of key concepts. Te first is the manufacturing pro-
cess definition or MPD. Te MPD defines the exact set of operations that a product must flow through in manufacturing as it is being assembled, tested, and packaged. Along with this definition of the ‘route’ the product takes through manufactur- ing it also includes the complete set of programs needed by equipment in manu- facturing, information about required fix- tures, detailed instructions for operators related to equipment setup, and, for manual assembly or inspection operations, a full set of instructions outlining exactly what the operator needs to assemble and/or inspect. Te second concept is the build record.
the build record is a complete history of exactly what has happened to any unit that has been produced by the operation. It con- tains: • a complete record of every operation and equipment that the product went through during production
• detailed traceability informa- tion identifying what material was added to the product at each operation
• information concerning what operator was working on the prod- uct at each operation
• data concerning key process parameters collected from the equipment that was used in assem- bling and testing the product
• all measurement results from every test and inspection operation • additional quality information
16 – Global SMT & Packaging – February 2011
Figure 2. Powerful material management systems identify when a moisture sensitive component must be dried, increasing overall quality.
such as a full defect and repair his- tory for the product
Process validation
and control Te definition of the MPD is a prereq- uisite for an MES system and is the basis for enabling good process validation, and more importantly,
control. Tis starts
from the basis of having a system in place that enforces that the product follows the proper MPD. Tat is, the system needs to have the capability to ensure that a prod- uct follows the exact routing that is defined in the MPD. If, during manufacturing, the product moves to an operation that it is not supposed to be at (because it is not part of the MPD, or earlier operations in the MPD have not been passed successfully) the system should alert the operator that this unit should not be at this operation and let them know where it should be. Te most advanced systems provide
additional capabilities such as: • interlocking automated assembly equipment such as SMT place- ment machines when a unit is not properly following the MPD
• verification that the proper NC programs are loaded on automated assembly/test equipment and that key settings on the equipment are within required tolerances
• verification that all fixtures and material (components, sub assem- blies, and consumables) are correct
for the particular operation and unit
• automated, paperless, delivery of the correct revision of assembly and inspection instructions to operators
To provide a comprehensive set of process validation and controls in the operation, the MES system needs to have coverage of all key operations and equipment in the factory from screen printers, through SMT placement machines, reflow ovens, manual assembly stations, wave solder machines, AOI, ICT, and functional testers, manual inspection locations, system assembly loca- tions, etc. A site’s operators are a key part of its
manufacturing capabilities, and ensuring that they have the proper skills and training to perform key assembly and test related tasks on specifics product can be challeng- ing. More importantly, it is key that a man- ufacturer has the ability to validate that all operators working on a product have the proper training to perform their assigned tasks when manufacturing a product. A good MES system will have the ability to manage the details of all the operators in a site along with their skills and qualifica- tions. If during production, an operator is found to not have the prerequisites to perform a given task assigned to them, the system needs to alert the operator in ques- tion, and when possible interlock the par- ticular equipment until an operator with the proper qualifications logs into the
www.globalsmt.net
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80