When we are making PCB boards, we often have common problems with circuit boards caused by humidity, which leads to changes in circuit parameters in the circuit board and circuit board failures. The circuit in the circuit board is in a short-circuit condition, resulting in circuit board failures and signal processing or transmission lines are open. , Causing the circuit board to malfunction.

Common problems with circuit boards caused by humidity

The definition of dampness means that it contains more water than under normal conditions, so the circuit board used in a humid environment, because the air contains relatively large humidity, when the humidity is too large, it will turn into water droplets and fall to the circuit board. When the water droplets fall on the circuit board and disperse on the circuit board, they will attach to each pin or printed line of the electronic component.

Since the electronic components currently used in circuit boards are all SOP or SSOP SMD components, the spacing between pins is very fine, especially for SSOP packaged integrated circuits, the spacing between pins is very fine. When moisture is converted into water drops on the pins of the SSOP package integrated circuit, if the circuit board is in operation at the moment, an invisible resistance will be added between the pins of the integrated circuit (because water is conductive), or even worse. It will cause a short circuit, causing the circuit board in working condition to show faults.

If the water droplets converted from moisture drop between the pins of the electronic components on the circuit board, and the circuit board is just in a non-working or power-off condition, it will not immediately cause damage to the circuit board, but the pins of the electronic components Or after the printed lines are moistened by water droplets, the pins of the components will be rusted. Over time, the feet will be broken due to corrosion and cause circuit board problems. After the printed lines are moisturized by water droplets, especially the signal transmission lines are relatively fine. After being moisturized for a period of time, the printed wire will appear to be broken, causing the circuit board to be unable to operate when it is put into work.

Regarding the causes of circuit board problems caused by moisture, they are classified into three categories:

1. Cause the circuit parameters in the circuit board to change and cause the circuit board to malfunction;

2. Cause the circuit in the circuit board to be in a short circuit condition, causing the circuit board to malfunction;

3. The signal processing or transmission line in the circuit board is broken, causing the circuit board to malfunction. We can formulate relevant measures based on these three items to reduce or avoid the occurrence of circuit board defects due to wetting of the circuit boards in the equipment under your jurisdiction.