Single Sided Flexible Circuits

What Single Sided Flexible Printed Circuit (FPC) is:

A single-sided flexible printed circuit (1 layer flex circuit) is a flex circuit with one layer of copper trace on one substrate (normally Polyimide), and with one layer of Polyimide overlay laminated to copper trace so that only one side copper will be exposed, so that it only allowing access to copper trace from one side, comparing to dual access flex circuit which allows access from both top and bottom side of a flex circuit. 

As there’s only one layer of copper trace, it is also named as 1 layer flexible printed circuit, 1-layer flexible circuit, or even 1-layer FPC, or 1L FPC.
This is the simplest stack up of flex circuits and also the most popular flexible circuit board used before, because the thinnest thickness, 1 layer FPC is the most flexible than other types of FPC and this is one of the reasons why people turn from Rigid Board to flexible board. 

The lead time is the shortest (can be made within 24 hours) as you can see the manufacturing process is compared simply. If you want to replace the wire/cables to reduce assembly difficulty and avoid potential mistakes, the single-sided flex circuit is the best solution

Single Sided Flexible Printed Circuits

Single Sided Flexible Printed Circuits

1 Layer Flexible Printed Circuit (FPC) Stack Up


For the normal flex circuit, there’ll always be an adhesive layer between Polyimide and copper, and the thickness is similar to Polyimide, so people will choose to “ignore” that layer and you will not see it most of time. But for better understanding, we will list it bellowing:

1 Layer Flexible Printed Circuit (FPC) Stack Up

If you want a thinner thickness and more flexibility, then an adhesiveness base material will be your choice. There’s no adhesive /glue between copper and Polyimide, so the total FPC thickness will be thinner than the same FPC with the same copper and Polyimide thickness. See stack up bellowing: (0.11mm VS 0.13mm)

polyimide and copper

And the thinnest thickness of 1 layer flex circuit Best Technology can make is 0.06mm. See details:

There’s various stack up combination for 1 layer FPC, click to download the basic stack up of flexible circuits in Best Technology.
Normal Stack Up: 
Adhesiveless Stack Up: 
In normal stack up, adhesive layer will be hided so that customer can focused on other more important elements. Bellowing is two stack up /layer up and the only different is Coverlay material: One is Polyimide (the most popular one) and another is soldermask oil

One is Polyimide

another is soldermask oil

(Solder mask Type - Single-Sided Flex PCB)

Manufacturing process:


For Single-Sided Flex PCB, here are the basic manufacturing processes following up IPC 6013 standard  See more details, please check Flex Circuit Manufacturing

Flex Circuit Manufacturing



Here are the major application of 1 layer flex circuit, but not limited to:

  • Optical Pick-up for A/V & Computer (or CDP & DVDP)
  • Digital Camera
  • Capstan Motor for Camcoder & VCR
  • Vibration Motor for Mobile Phone
  • Stepping Motor
  • Membrane switch 
  • Flexible wire cable
  • Static application
  • Printer
  • Robot (arms)
  • Antenna


Product Photos:

Here are pictures of single sided flex circuits (BFS17043 top and bottom).


single sided flex circuits top         single sided flex circuits bottom


You can click to see more pictures of single sided flex circuit board to see how it can be useful for your application. 

Welcome to contact Best Technology  to see more information about single sided Flexible circuit board.

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