In Printed Circuit Board (PCB) design, solder jumpers (also known as solder bridge jumpers) are a technique used to create a connection between two points on a circuit board track.
Understanding Solder Jumpers
A solder jumper typically consists of a pair of conductive pads placed very close together on a PCB trace. These pads are designed so that a small amount of solder can be applied to bridge the gap between them, forming a connection.
How They Work
- Connection Method: A technician applies a blob or ball of solder across the two pads.
- Purpose: This physically connects the trace on one side of the gap to the trace on the other side, completing a circuit path.
- Functionality: They are essentially manual switches or configuration options built into the PCB layout, allowing a connection to be made or left open during assembly.
An Alternative: 0 Ohm Resistors
While a direct solder bridge works, a cleaner and often preferred method for creating this type of connection is to use a 0 Ohm resistor.
- What it is: A 0 Ohm resistor is a component that looks like a standard surface-mount resistor but has essentially zero resistance.
- How it's used: Instead of pads for a solder ball, the PCB layout includes standard footprints for a resistor component where the connection is needed.
- Advantages:
- Cleaner Layout: It uses standard component footprints, making the board look more professional and organized.
- Reliability: Soldering a component is often more reliable and consistent than creating a solder bridge.
- Availability: 0 Ohm surface-mount resistors are very common, low-cost, and readily available.
- Automated Assembly: Using component footprints allows for automated pick-and-place assembly.
Using a 0 Ohm resistor provides the same electrical connection as a solder bridge but integrates better into modern surface-mount PCB assembly processes.
Conclusion
In summary, a solder jumper on a PCB is a pair of pads designed to be connected by a solder ball to complete a circuit trace. Although simple solder bridges are used, the practice of bridging pads with a 0 Ohm resistor component is widely adopted for its benefits in manufacturing and board cleanliness.
