Issue link: https://iconnect007.uberflip.com/i/793332
44 SMT Magazine • March 2017 panels are not kept flat during the pick and place process the SMT equipment can misplace components, leading to addi- tional rework. Breaking out cir- cuits from panels can also be an issue as often only thin layers of FR4 are used, which can lead to damage if handled incorrectly. Las Marias: How should these challenges be addressed? Poppe: We would recommend working closely with the PCB supplier and perhaps invest- ing in bespoke pallets or carri- ers. If the design is stable and the volumes are high enough, then the initial cost of the pallets might make sense. If your policy is to run stan- dard oven profiles, then it's likely that you will need to refine these—particularly if pallets are used as the oven profiles will vary significantly compared to a standard profile. Las Marias: How different is the flex circuit assem- bly from the standard PCB assembly, and what are the important factors to consider? Poppe: You could argue that the processes are very similar—providing you are already working to best practice! Care and attention should be given to panelization, circuits should be baked prior to assembly, and oven profiles should be tailored to suit the circuit being assembled. A ro- bust NPI procedure should cov- er most of these points already. Las Marias: Which end-applica- tions are you seeing increasing use of flexible circuits? Poppe: The demand for flex cir- cuits in the sectors we serve— industrial electronics—is still relatively low. Clearly, there is much higher demand in auto- motive applications and con- sumer electronics, whether there is a significant increase in demand within the industrial sector remains to be seen. Las Marias: When choosing an assembly partner for flex circuit assemblies/projects, what are the top things to consider? Poppe: Robust NPI process; good material han- dling and preconditioning process prior to as- sembly (i.e., baking and dry storage; ensuring the manufacturer that you partner with is the right fit—that is, do they have demonstrable ex- perience in producing similar products and flex circuits?) and design for manufacture support on PCBA. Las Marias: Thank you, Russell. Poppe: Thank you. SMT JJS STRESSES THE NEED FOR BAKING PRIOR TO FLEX-CIRCUIT ASSEMBLY Russell Poppe At the recent IPC APEX EXPO 2017 in San Diego, California, Steve Godber, LED Commercial Manager at Al- pha Assembly Solutions, discusses with I-Connect007's Stephen Las Marias the reliability and voiding challenges in the LED market, and how the company is helping their customers address these issues through their solder tech- nologies. Watch The Interview Here Real Time with...IPC: Alpha Discusses Improving LED Reliability Issues