What is Controlled Impedance?

Controlled Impedance PCB (also refers to Impedance Control printed circuit board), Controlled impedance is the characteristic impedance of a transmission line formed by PCB conductors. In controlled impedance PCB, impedance cannot to be confused with resistance, although they are both measured in Ohms (Ω). Because resistance is a DC characteristic, while impedance is an AC characteristic.

Controlled Impedance PCB

Controlled Impedance PCB

Today PCB designers are driven by the pressure of speeding up signal switch, corresponding to the shorter signal transmission times and higher clock rates of modern digital circuits. PCB traces are no longer simple connections, but transmission lines. It is very important for PCB design engineers to understand how to control the impedance of PCB traces.

How we do it?

Venture provides free stack-up and impedance control calculations suggestions to customers. Our experienced engineers are ready to help you 24/7. We can work with your team at the conceptual stage of the controlled impedance PCB design to help you obtain the best results in controlling impedance, through selecting the proper material and layer stack up.

We control impedance by varying the dimensions and spacing of the trace or laminate, and perform a test to make sure that we achieve the requested impedance using TDR coupons. We at Venture are experiencing increasing demands for multilayer PCBs with controlled impedance requirement. An estimated 60 % of the multilayer PCB’s with six layers or more are controlled impedance PCBs. We believe in the near future, all PCB’s will likely include at least some impedance requirements.

Controlled Impedance Test System

Controlled Impedance Test System

Venture manufactures controlled impedance PCB (printed circuit board) using the latest materials and technology. We have full strict Incoming Inspection (IQC) for all laminates, pre-preg and copper foil, since raw materials’ thickness variances are some of the main challenges for producing controlled impedance PCBs.

We also use LDI (laser direct imaging) equipment that eliminates the variances in trace width, once a controlled impedance board is imaged, it must go into the etcher. The purpose is to develop a configuration on an etcher to minimize undercut. With our 10 years’ experience in the controlled impedance PCB industry, Venture understands how to manage the etch process to make sure that we meet the requested impedance tolerance data.

LDI Machine

LDI (laser direct imaging) Machine

Through our 2 hours rapid response services from our 24/7 sales and tech support team, and excellent after-sales service, we will be your best controlled impedance PCB manufacturer & supplier in China. At Venture we can answer any controlled impedance PCB questions that you may have, please feel free to contact us anytime.