What is Flex?
Flex circuits are the newer technology to rigid circuit boards that have arisen in popularity and need in recent years. Some types of applications flex is used for would be small to moderate size products including hard disk drives, engine management units, anti-lock braking systems, airbag controllers, cameras, hearing aids, plus many more. The advantages to flex is in the name: flexibility. With the ability to be elastic, circuits can now populate components around the folds, creating more real estate for intricate operations. The flexible nature of the circuits also negates the need of wiring and eliminated the margin of failure of connections, overall increasing the reliability of circuit boards. Inline with it’s nature, flex PCBs are space and weight friendly, increasing it’s usability in various applications that are either small or light weight. Furthermore, one of the downfalls of rigid boards that flex boards make up for is the amount of vibration that rigid boards, through their nature, have to go through. Using flex PCBs increases the integrity of the soldering and component connections, making the possibility of failure due to movement small.
Advantage is the Disadvantage
Although Flex PCBs are the better option, the nature of the circuit board is also its most challenging characteristic to manufacture. Because of the unique operations and the respective requirements of each operation to assemble a flex circuit board, it is difficult to produce a high quality and inexpensive assembly quickly when handling the flex individually. This calls for the fixture and automation of assembly, which can prevent damage or contamination of the flex, while decreasing cost of production and time-to-market.
Up until now, surface mount technology (SMT) and Through Hole were the primary technologies to populate flex circuit boards with components and connectors. However, due to the growing demand of smaller components and footprints, other technologies to combine with SMT and Through Hole have been researched to create a better stream-lined automation process for assembly. Two rising interconnect technologies that have been created to combat this need would be Chip-on-Flex (COF) and Flip-Chip-On-Flex (FCOF). COF refers to the assembly technology where a microchip or die is mounted and connected to a flex circuit, which is the method now used for small analog and digital die. Working off the advantages of COF, FCOF negates the need for wire bonds that are required for COF, overall reducing the integrated circuit footprint. Together with SMT and Through Hole, these technologies can be mixed and matched on the same flex circuit.
Automating the Process to Reduce Costs
The biggest obstacle in flex PCBA is automation. With most equipment manufacturers catering towards rigid circuit board assemblies, cost effective options are slim. Having custom operations requires custom equipment and processes designated to flex assembly. To combat this, Integrated Mirco-Electronics, Inc. has developed custom factory automation technology designed and produced in-house for our manufacturing sites. In response to the growing needs of OEM customers, these factory automation technologies are custom tailored to each unique product and have turn around times as short as a few days. Without a strong capability for factory automation and fixturing, flex manufacturing can be a costly operation with ongoing concerns for quality and reliability. IMI, Inc. is on the leading edge of these capabilities and have the methods and technologies to produce high quality and cost effective flex assemblies tailored to each client. To read full white paper: click here. To learn more about IMI’s flex capabilities, visit: www.northamerica.global-imi.com.