When a designer is embarking on their first flex or rigid flex layout the challenge of learning a new material set and new design rules is often compounded by the added challenge of researching and selecting a new fabricator who has the capability to manufacture flexible materials. It really isn’t surprising, there are many fabricators that work with both rigid materials and flexible materials, but there are also many that specialize in only rigid materials.
If you need to start the search for a new fabricator, where do you start? To simplify things, I think we could break the key items into three categories: technical capabilities, soft skills and quality systems.
It is important to understand that just as there are design related differences when moving from rigid materials to flexible materials, there are a few significant processing differences during fabrication as well. For example, material handling is much more critical. Flex materials can be as thin as .003” - .005” with no glass reinforcement, and any small ding or dent in that laminate will likely result in scrap in the final product. As another important example, the same equipment that is used to run the rigid panels is often used to run the flex panels as well. These thin, flexible panels are prone to getting caught up in rollers and scrapped during processing if special precautions such as taping flex panels to leader boards are not in place. Some fabricators run a few flex panels through their facility, some have a greater percentage of their business with flexible materials and others specialize in only flex. It is important to be sure that you are aligning yourself with the best fit for your long-term needs.
What percentage of your business is flex or rigid-flex?
Are you comfortable that the fabricator has enough experience with flex to help guide you through not only your first design, but future requirements?
What percentage of your business is single-sided, double-sided, multilayer or rigid-flex?
Does this align with the flex constructions you are likely to need in the future? Each of these technology levels requires a slightly different skill set.
What are key technical capabilities such as minimum line width/space and minimum hole size? What is standard versus emerging technology in flexible-only constructions?
Capabilities in these areas can vary greatly between fabricators—do these capabilities fit your requirements?
What is standard versus emerging technology with rigid flex capabilities?
Will you require multiple laminations, microvias, or other advanced technology?
What are the preferred materials in stock?
Does this fit with your design goals? Flex materials can have long lead-time and high minimum lot requirements. Understanding the material sets and properties is critical.
What is standard lead time? What expediting options are available?
Prototype and production lead time varies greatly among flex fabricators. Some specialize in quick turn, some do not. Be sure that these capabilities match with your project goals.
Watch Tara Dunn's conversation with Judy Warner about Flex Cost Drivers.
UL recognition is based on UL approved materials and the fabricators manufacturing process. Each specific stack-up is recognized. Because there is such a significant number of combinations possible with flex materials, it is more difficult to find a UL recognized supplier for flex materials, than rigid materials.
Soft skills are often overlooked in this process yet are critical to the long-term success of a business relationship.
What is the response time to initial questions?
Incoming inquiries for new business should receive high priority, if there is a slow response at this point, there will likely be slow responses for other communication.
Are you able to easily call and reach someone or is communication primarily through email?
Learning a new technology can be challenging and often a phone call can clear up confusion much more efficiently than email.
Is there an FAE or technical person well versed with flex dedicated to answer questions regarding stack up, materials and general design questions?
This may not be required for simple designs, especially if customer service has technical skills, but may be important as technology levels increase.
How long did it take to respond to a quality survey and is the response complete?
Timely and complete responses are an indicator of future communications.
Is there enough flexibility in systems to allow you to pre-order material if there is a lead time concern?
This short list is not by any means intended to be an all-inclusive list, but simply a place to start discussion. There are a wide range of technical capabilities when looking for flexible circuit fabricators and understanding those capabilities and how they support both short term and long term plans for flex and rigid-flex designs will help ensure a long-term relationship with your fabricator.
With Altium Designer®, you’ll have access to the tools you need to create any rigid-flex design you can imagine, examine its mechanical behavior, and prepare your board for production, and all within a single program. Talk to an Altium expert today to learn more.