SMT007 Magazine


Issue link:

Contents of this Issue


Page 19 of 83

20 SMT Magazine • March 2017 by Stephen Las Marias I-CONNECT007 In an interview with SMT Magazine, Steve Fraser, VP of Operations at Firstronic, discuss- es the challenges they face in flex circuit assem- bly and strategies to ensure the reliability of the products. Stephen Las Marias: What do you think are the major challenges in flex-circuit assembly? Steve Fraser: We are predominately working with rigid-flex circuit automotive lighting appli- cations. One of the issues we are seeing is that while these boards used to be shipped in a rig- id panel, they are increasingly coming in non- rigid panels. This is because LEDs tend to use metal backing rather than FR4. The cost of met- al is high enough that to reduce material cost, panels are shipped in flex format. However, the tradeoff is that when this is done, the flex pan- els must be palletized. This drives added tooling cost since it requires 25–30 pallets to run prod- uct on an SMT line without impacting through- put. Post-SMT, panels/boards then require flat trays and carts for movement among produc- tion operations, which may or may not be com- patible with a manufacturer's existing PCBA handling equipment. An additional challenge is that the bond- ing material used to bond to the rigid portion is moisture sensitive, which means the product needs to be kept in sealed-in bags until ready for use in production. Typically, they must pass through the SMT process within four hours of opening to prevent unacceptable moisture ab- sorption. Consequently, if you have serializa- tion requirements, you have serialize product inline or run small batches. In lieu of this, pre- SMT baking is required which adds time and cost and is a non-value added process. Finally, we have some applications that have bend and form requirements for the rigid portions. We re- ceive them flat, bend them first and then run them through the line formed, which increases the complexity of the required pallet. Las Marias: What specific steps in a flexible circuit assembly process have the biggest effect on yields? Strategies for Addressing Flex Circuit Assembly Pain Points FEATURE INTERVIEW

Articles in this issue

Archives of this issue

view archives of SMT007 Magazine - SMT-Mar2017