Stack-up for FPC

Sorry, we cannot meet your needs. We recommend that you choose the regular.If you have further questions, you can contact your sales representative directly and she will answer them for you.

The DK of Pure gum is about 3.4, the DK of film covering is 3.8, and the DF is less than 0.04.

Hello, thanks for your question. For what you said, we can do it.

The inner layer is usually made of double-sided material, which can be 50um. If you want 100um, you can use two single-sided materials to laminate them, and the thickness including glue is 113um.

So it would be best to use a stack-up like a 6 or 8 layer, and then have some inner layers with no copper but instead serving as a spacer where I can get spacings of 50, 100, 150 um and so on, using 1, 2, or 3 sandwiched polyimide layers respectively?

Yes, you can do this.

It's difficult to have thicker copper on the inner layers than on the outer layers of a 6-layer board. Typically, the inner layers are made using 1/3 oz copper.

Hello! Here are the responses to your three questions: 1. It can be produced. 2. The minimum thickness of the flexible area is 0.07±0.05mm. The copper can be positioned at the center of the flexible part, aligned with the neutral axis. It is best to design with mesh copper, which is more conducive to bending. 3. For static bending, the bend radius is 2.5mm; for dynamic bending, the bend radius is 20mm.

Areas with more pads usually require components to be soldered and cannot be bent. You can upload your specific gerber files and requirements together to our pricing page, and a professional will review them for you.

Thank you for your questions. Here are the responses: The stiffener does not need to be at the edge of the FPC. It can reinforce only part of the area and does not need to cover the entire section. Vias can go through the stiffener. Components cannot be mounted on the stiffener because it does not have pads or traces. Components can only be mounted on the other side of the stiffener. Through-hole components can go through the stiffener and be soldered on the other side. — This applies when the stiffener is on the surface.

Thank you for the response, but I'm not sure if you fully understand my question. I understand that the stiffener does not have pads or traces. As such, the standard stiffener options (TOP/BOT/both) do not allow mounting of SMD components on the side with stiffener. However, the Avanced Option "Stiffener between top and bottom edge connector" states: "The stiffener is just laminated between top and bottom edge connectors to rigidize the edge connector area and do not influence contact on both top and bottom layers." The accompanying image suggests that this allows for exposed pads on both sides. Therefore, if I have a 4 layer flex PCB, can I have the stack: SMD-Cu1-Cu2-Stiffener-Cu3-Cu4-SMD with vias throughout? (I have omitted the other layers for clarity)

The type of stiffener you mentioned is something we can theoretically produce. However, we need to review the relevant documents to confirm. Could you please upload the relevant files to our quotation page?

The common coverlay specifications include Shengyi's SF202 1012DTN250A KNV, SF305 051813DR, SF305 051813SE, and SF305C 1035. Their dissipation factors are 0.0068 (@1Mhz）, 0.0191（@10Ghz), 0.0188（@10Ghz), and 0.0205（@10Ghz), respectively. Later on, to make it easier for you to review the corresponding specifications, we will compile them into a document and place it in the help center. I will notify you as soon as it's ready.

Have you compiled and posted this document anywhere, I am interested in it as well.

I will notify you as soon as it's ready.