HTD PCB manufacturer expert: Consider the component factor during impedance design

HTD PCB manufacturer expert: Consider the component factor during impedance design

Match component impedance:
This information should be found in the component data sheet.

Once you have this information you now know the required impedance value of the track you need to connect these two components.

Track characteristics: track length, width and thickness, its proximity to other tracks, ground planes, laminate thickness and dielectric constant (Er) are all important factors to consider.

For tracks located on outer layers the thickness of the solder mask must also be taken into consideration.

Use a Microstrip: This is a trace on one layer separated from a plane on another layer by a material (such as the substrate).

Remember the antenna example?

A substrate acts like the cable insulator and the plane acts like a shield.

Microstrip configurations are popular because you can use impedance calculators or field solver software to give you recommended trace dimensions based on the impedance you require and the parameters\configuration you are using.

Different configurations and combinations of these Microstrips can be used:

Surface:
Trace on one side and a copper plane on the other.

Coupled:
Where you have more than one trace on one side and a copper   plane on the other.

Embedded:
Where the trace(s) are sandwiched between the substrate with a copper plane on one side.

Stripline:
Where the trace(s) are sandwiched between the substrate with a copper plane on both sides.

Using these methods, where you calculate all the parameters in order to control the impedance is often referred to as “Controlled Dielectric”.

This is sufficient for a lot of designs, as long as you specify the parameters to your manufacturer and they stick to the specifications.


You can calculate your impedance for free here.