Electronic PCBs Tested For Quality
The circuit board is the critical connecting path for the entire device and any mistake in this stage can impact the performance of the product. It is therefore crucial to ensure that the PCBs are tested for quality before they go into final assembly. These tests can catch mistakes like scratches, dings and misalignments in copper traces that may result in intermittent failures later on.
Bare electronic pcb board are subject to a number of different testing procedures depending on the quality standards set by the manufacturer. This includes a visual inspection that examines the appearance and dimensions of the PCB. The bare boards are also subjected to electrical tests to check for shorts and open connections. The resulting report provides details about the integrity of the circuit board and highlights areas that need further inspection.
A bare board is usually also subjected to stress testing to test for long-term reliability against idealized environmental conditions. For example, the bare board might be subjected to an electrostatic discharge (ESD) test that simulates the flow of electricity between two charged surfaces. This can cause the surface of the bare board to dissipate and damage the components on it.
How Are Electronic PCBs Tested For Quality?
Other tests that can be performed on a bare PCB include an ICT test, which checks for solder connections. This test uses fixed probes arranged in a pattern that matches the underlying PCB layout and makes contact with the copper lands on the circuit board. The test probes are then pressed against the board by a rigid needle adapter or “bed of nails.” The ICT test can spot problems with solder connections like open circuits or shorts.
Another popular inspection method is automated optical inspection (AOI). This non-invasive testing technique utilizes cameras to analyze the surface of a bare board for defects such as dents, scratches and missing parts. AOI is highly effective in identifying visual defects before they become problematic during assembly. It is also useful for detecting welds on BGA and CSP packages that are hard to inspect with other methods.
A thermal imaging test can reveal defects in the board’s heat transfer system. The test can detect hot spots, cold spots and voids in the insulation material used to protect the conductive layers on the pcb board. The test can also pinpoint polarity issues with the circuit board’s solder connections.
If a bare PCB fails these tests, it must be replaced before the device can go into production. This can lead to costly delays and a waste of resources. It is therefore in the best interest of a PCB manufacturer to invest in thorough and cost-effective testing during production. This can help them avoid expensive mistakes that can negatively impact the quality of their products and customers‘ satisfaction. In addition, these early tests can reduce the amount of time and money that is required to perform further testing on populated PCBs. This is because the later testing processes are more efficient when they can rely on the bare-board inspection and functional test results.
