What Is the Standard Lead Spacing for Capacitors | How Does It Matter?

There are hundreds of standardized lead spacing for capacitors. 5mm is standard capacitor lead spacing for small film radial capacitors. When you’re making a design you’ll just have to pick the package you want. 

For a specific value of capacitance and voltage, there may be a range of standard packages. The manufacturers provide you with a matrix that shows the range of lead spacing vs voltage and capacitance for a specific type of capacitor.

What Is the Standard Lead Spacing for Capacitors?

For capacitors, international standards are set by the IPC(Institute of Printed Circuits). This association aims to standardize the assembly and production requirements of electrical components. 

Figure: Capacitors of various lead spacing.

If the lead spacing of your manufactured capacitor doesn’t match the hole spacing of your PCB, you’ll have to bend the leads. This will save the capacitor from excessive mechanical stress. But avoid bending it right next to your capacitor’s body. 

What Are the Leads on a Capacitor?

Capacitors have two leads- positive and negative. To tell the leads apart, check the marked signs on the capacitor’s body. The lead closest to the negative sign is the negative lead. Another way is to look at the length of the leads. The shorter and longer leads are the negative and positive leads respectively.

Figure: Leads of Capacitor.

Lead Spacing Guide

Manufacturers provide lead spacing guides for capacitors. You’ll have to check them before making purchases. 

Do You Need to Extend Capacitor Leads?

You need to extend the leads of your capacitors if they are too small. Sometimes you’ll need to bend your capacitor leads to fit them in your design. Small leads of capacitors prevent you to bend them.

How Do You Extend a Capacitor Lead?

Step-1: Cut the wires you want to add to your capacitor’s short ends.

Step-2: Hold the wire to the end of your capacitor and melt it with your iron and connect them. Perform the steps as the following figure.

Does Length of Capacitor Matter?

The length or physical size of capacitors doesn’t matter as long as the capacitor and voltage ratings are the same. The exception occurs where a switching power supply with low ESR capacitors is used. The only concerning matter is the space between the leads of your capacitor for fitting it on a circuit board.

However, the leads of your capacitor must be short. Long leads of capacitors limit their ability to pass high-frequency signals. So, the leads must be less than 1.5mm to avoid inductive effects while passing high-frequency signals.

Conclusion

The lead spacing of the capacitor or the pitch of a capacitor isn’t its electrical characteristic. These pitch dimensions are for mechanical fits only. They mate with the corresponding distance of the holes of your board.