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The Relationship Between Circuit Boards and Fuses

The Relationship Between Circuit Boards and Fuses

In this article, we will talk about the relationship between circuit boards and fuses, as well as their uses and characteristics.

First, let's take a look at what a circuit board is and the definition of a fuse.


  • Circuit:

Printed circuit board, that we also call them printed board, English abbreviated as PCB (printed circuit board) or PWB (printed wiring board).

We use the insulating board in the base material,  cut to a certain size,  and it attach to at least one conductive pattern , and  holes (such as component holes, fastening holes, metallized holes, etc.)  arrange to replace the chassis of the previous electronic components, and realize the interconnection between electronic components. Because such we make such board that using for electronic printing techniques,  we call them "printed" circuit boards.

  • Fuse:

Fuse is a protective electronic device.  It is usually connect in series in the circuit.

When the fault current increases to a certain value,  it will fuse by itself and cut off the circuit or heat itself up,  causing the resistance to rise sharply to prevent the current, that from passing through the circuit, and achieve the protection circuit. The purpose of other devices in the circuit.  The most commonly use in circuit overcurrent protection components is the fuse.

The relationship between the circuit board and the fuse

PCB boards and components form a circuit board.

And the fuse is a kind of components.

However,  not all boards have fuses.


  • Circuit:

The circuit board makes the circuit miniaturized and intuitive, and plays an important role in the mass production of fixed circuits,  as well as the optimization of the layout of electrical appliances

  • Fuse:

When a large overload current occurs in the circuit,  the fuse should cut off the overload current within a specified time , that to protect the safety of the components,  and other electronic or electrical equipment in the circuit.


1.Circuit boards

We divide Circuit boards into three major categories: single-sided,  double-sided,  and multi-layer circuit boards,  it’s according to the number of layers.

  • ①Single-sided: On the most basic PCB,  we concentrate the parts on one side,  and it is concentrate the wires on the other side. Because the wires only appear on one side, we call this kind of PCB a single-sided circuit board. Single panel is usually simple to make and low cost,  but the disadvantage is that it cannot apply to too complicated products.
  • ②Double-sided is an extension of single-sided.  When single-layer wiring cannot meet the needs of electronic products, we can use double-sided . Both sides have copper cladding and traces,  and it can can conducte the lines between the two layers,  through vias to form the required network connections.


  • ③A multi-layer board refers to a printed board,  whitch with more than three conductive pattern layers,  and insulating materials in between,  and the conductive patterns are interconnected as required. Multilayer circuit board,  is the product of the development of electronic information technology in the direction of high speed, multi-function, large capacity,  small volume,  thinning and light weight.

We can divide circuit boards into flexible boards (FPC),  rigid boards (PCB),  and rigid-flex boards (FPCB) according to their characteristics.

  • ①Fuse tube:

The most common type of fuse,  the outer shell is made of glass or porcelain shell, and the interior is a fuse.  It  generally use in power sockets,  electronic equipment, DVD, VCD,  TV and other places where AC power is input.

  • ②Resettable Fuses (Thermistor Type)

It is made of a mixture of high molecular polymers and conductive materials.  When the normal working current passes through, the fuse is in a low resistance state;  when there is an abnormally large current in the circuit, the fuse is in a high resistance state;  at that time,  the large current in the circuit disappears,  and the high current in the circuit disappears, the fuse is in a low resistance state again.

  • ③Thermal fuse:

The temperature of the equipment rises abnormally.  If the temperature exceeds the allowable abnormal temperature, the thermal fuse will automatically fuse. And cut off the power supply to prevent further damage to the electrical appliance, and prevent fire.

  • ④Fusible Resistor:

Also known as a fuse resistor. This is a component that has the dual functions of a resistor and a fuse.  When the circuit board is working normally,  the heat emitted under the rated power of the fuse resistor. It balance with the surrounding medium,  and it has the function of a resistor. While the circuit abnormally overload and exceeds its rated power,  it will blow like a fuse. So that the connect circuit disconnect to protect the component.

How the board and fuse are connected

The fuses are either plug into the board or attachto the board.

If it attach to the circuit board, we call it Surface Mount Technology(SMT).