Gadget and Technology

Flexible printed circuits offers design choices that can reduce your product cost, enhance products features as well as improve the robustness, if the right steps are taken in your product start up. Following these guidelines will help a designer or engineer more successfully utilize flexible circuit technology into packaging solutions.

Do a little research on flexible circuit terminology as this will help with supplier communication and result in a better design. Many terms used by your suppliers are industry specific terms. There are many sources for design guides or terminology including the IPC (see “Terms and Definitions for Interconnecting and Packaging Electronic Circuits” IPC-T-50 Rev. H). You don’t have to become an expert, but understanding the proper terminology will go a long way in improving the design process.

Choose the right supplier for your needs; there are many flex circuit manufacturers that would gladly do business with you, but not every supplier is going to be able to fill your specific needs. You need to ask a lot of questions about your future supplier. Does the potential supplier have experience in your industry? Can they demonstrate proficiency in the design your are trying to build? If it has fine lines, what is their demonstrated capability for line width and spacing? How long have they been building flex circuits, what is their long term viability, is the management team committed to continued investment in this technology. These and other questions should be part of your due diligence in selecting the right supplier. You should also talk to other customers of your prospective supplier; insist on getting customer references as a condition of doing business. Talking to a few of the suppliers customers can give you a ton of insight on what it is like doing business with them.

Follow design input from your supplier. Your supplier understands how to make a reliable circuit and knows the limitations of its manufacturing capability. Forcing your design on your flex circuit supplier is a sure way to reduce the reliability and increase costs. Sharp conductor corners create stress points; radius turns will have a longer life. Cracked conductors at solder joints are very common in poorly designed flex; this issue can be mitigated during the design phase. Filleting the intersection point between a trace and a pad tends to distribute stresses that might occur when the circuit is bent. Many suppliers will offer comprehensive redesign to insure that common reliability issues are addressed and the design is manufacturable.

Developing a technical contact at your flexible circuit supplier can dramatically improve communication and smooth the product introduction process. A strong relationship can help assure mutual investment to the success of the program. Communication with a contact that can explain the processes, materials, design guidelines and cost implications will make the project more likely to succeed and improve the experience.

Make sure that your supply chain team understands that a flexible circuit is custom designed and engineered with unique features specific to the end use application. Assuming that this product is a commodity that can be purchased anywhere will often lead you to higher costs, poor delivery and reduced reliability.

Allow enough time in your total project to take advantage of your suppliers expertise so that you can incorporate cost savings ideas and improve the design robustness. An overly compressed time line will result in higher costs and lower quality as the supplier is forced to produce a poorly designed product in a quick turn environment.

Analyze the entire cost of ownership as opposed to just looking at the product price. Using an off-shore supplier might look like you are saving money, but communication issues, lack of timely technical support, travel costs and delayed project start up costs can quickly eat up any piece part savings that an overseas supplier gives. Some of the lowest cost flexible circuits are made in the United States. These companies are using highly automated equipment and can compete with anyone in the world. Other US suppliers specialize in lower volume with high product mix production, an area that many overseas producers will struggle at.

While most of the above items seem like common sense to the experienced flex user, many times, buyers seem to dramatically under estimate what is involved in successfully utilizing flexible circuits in their electronic packages. Utilizing some of the guidelines given in this article will hopefully improve your chances of a successful start up.