Utilization of a vendor qualification checklist as part of your vendor qualification procedure is a simple way to ensure that design criteria and manufacturer capabilities are properly addressed. The vendor qualification checklist should include, but is not limited to, the following:

1. Company and site information

• Is the company ISO9000 certified?
• What is the company’s organizational structure?
• Site description
• Manufacturing history
  This information may be needed to meet contractual obligations and to help justify the selection of a manufacturer. It should also provide chain of command and reporting structure, workforce capabilities, and facility size.

2. Accreditations and standards certifications

• Is the manufacturer certified for the type of board that is going to be produced?
• IPC Standards
• Mil Standards
• Industry accreditations and awards
  What product class is your end-product required to meet? Is the fabricator capable of manufacturing to that class, as set by specific standards?

3. Process and product capabilities

• Process capabilities
• Panel size limits
• Board size limits
• Line width and spacing capability
• Aspect ratios
• Hole size limit
• Lamination methods
• Surface finish types
• Data transmission requirements
• Process precision
  Along with manufacturing-specific information such as conductor forming method, plating method, and image transfer process.
• PWB Testing
• PWB test methods
• Number of nets and nodes
• Probe point pitch and accuracy
• Test percentage in single pass
• Grid density and probe accuracy
• Netlist capability
• Test equipment limits for voltage, impedance

4. Product capabilities

• Multilayer layer count limit
• Via technology
• Via fill, including board thickness and hole size limit
• Number of nets
• Rigid PWB
  
• Rigid/Flex PWB
• Flex PWB
• PWB Materials
  Note that a process used in one material may not be appro priate or possible in others. One needs to be very specific in certain circumstances, when special processes are needed or exotic materials are being used. Also, one needs to know if certain processes are outsourced if the shop does not have the capability in-house.

5. Equipment list
The equipment information included can be useful in verifying actual capability or in determining which supplier may be a better choice.

• Quality control methods
  What control methods do they use to maintain their processes, and do they have data to substantiate?
• Quality development
• Customer reference
  Speaking with someone else who has used a particular manufacturer and has applied similar processes can help one to avoid process pitfalls.
• Delivery schedule capability
  The realistic delivery capabilities, especially when complex and special processes are being utilized, can cause disastrous consequences if rushed.

Understanding the basics of PWB fabrication and the requirements of a particular design, in conjunction with a vendor qualification checklist, will ease the selection of a PWB fabricator and reduce the need for on-site audit or vendor qualification. For more information about developing an exhaustive vendor qualification checklist for your unique needs, please contact the EMPF Helpline at (610) 362-1320.