Flexible PCB Microcircuits

As technology advances devices get smaller and the speed requirements of data transmission on circuit boards increases. Every flexible PCB is designed to perform a function inside an allotted space, but they also need to be manufacturable, need to be held to strict mechanical tolerances, and need to be cost effective.

With component sizing getting smaller every year, it allows very small flexible PCBs to include significant functionality along with being a passive component to provide connectivity in certain applications.

How Small Can a Flexible PCB Be?

The size of the microcircuit depends on the application but some of the key items that are important to many customers are:

  • Keeping a very tight outline tolerance.
  • Impedance values that can be held to +/-5% even in high volume applications.
  • Gold plating for use in connector terminal applications.
  • Using LPI solder mask on flexible substrate to keep solder mask damns intact.
  • Adding small stiffeners to allow one end of the material to be rigid.
  • Microcircuits require very fine line and spaces which requires specialized etching equipment.
  • In-house punch press and tooling manufacturing capabilities improves our time to market.

Flexible PCB Microcircuits Near a Penny

Miniature Flexible PCB Capabilities

The following table outlines our general capabilities for flexible microcircuits. However, every application is different so please contact us with your design questions so that we can review your application parameters.

Product Miniature Flex Circuits
Smallest PCB Size 5mm x 5 mm
Line Width and Spacing 0.002" (0.05mm)
Copper Thickness 1/4 oz, 1/3 oz, 1/2 oz 1 oz, 2 oz, and higher
Via/ Drill Size
Minimum Drill (Mechanical) Hole Diameter 0.004" (0.1 mm)
Minimum Via (Laser) Size 2 mil (0.05 mm)
Minimum Micro Via (Laser) Size 3 mil (0.07 mm)
Solder Mask/Coverlay
Solder Mask Bridge Between Dam 3 mil (0.08 mm)
Solder Mask Registration Tolerance 2 mil (0.05mm)
Coverlay Registration 8 mil (0.20 mm)
PIC Registration 7 mil (0.18 mm)
Stiffener Registration 8 mil (0.28 mm)
Thickness Tolerance 10%
Smallest Stiffiner Size 0mm x 0mm
Impedance +/- 8%
Steel Rule Die (SRD))
Outline Tolerance 4 mil (0.1mm)
Minimum Radius 4 mil (0.1 mm)
Inside Radius 20 mil (0.51 mm)
Punch Minimum Hole Size 28 mil (0.7 mm)
Tolerance of Punch Hole Size +/- 2 mil (0.051 mm)
Slot Width 20 mil (0.51 mm)
Tolerance of Hole to Outline +/- 2 mil (0.05 mm)
Tolerance of Hole Edge to Outline +/-3 mil (0.07mm)
Minimum of Trace to Outline 8 mil (0.20 mm)
Electrical Testing
Test Voltage 50 - 300V
Surface Finishes Available
Hard Gold, ENIG, ENEPIG, OSP, Immersion Silver, Immersion Tin, Plating Tin

Applications for Flex Microcircuits

The continuous miniaturization of devices has driven printed circuit boards to become smaller and denser and require more capabilities. Applications we supply mini flexible PCBs include:

  • High speed digital / RF / microwave connectors
  • Industrial sensors
  • Instrumentation consumables
  • Medical devices - wearables
  • Hearing aides
  • Semiconductor packaging
  • RFID Tags/antennas
  • And many more...

Epec is a leading experienced miniature printed circuit board developer and manufacturer with an eye on industry tolerances and customer service. We offer a full design and manufacturing services that can quickly adjust to meet any high or low volume demands you have.

Celebrating 65 Years of Manufacturing Excellence  Learn More →
America's Oldest. A History of Innovation.

Today at Epec, the customer comes first, and everything we do must be put through that filter. Whether it is developing e-commerce platforms to make it easier to work with us, or creating a NPI (new product introduction) process that helps our customers get to market faster, or the other 10 new projects we have in process, we must focus on building the new. By doing that every day, and by always making the customer our top priority, we plan on being here for another 65 years and then some.

Learn more about our 65 year story →

Celebrating 65 Years - Epec Engineered Technologies