1. IN-CIRCUIT TESTING
In-circuit testing (ICT) is the most robust type of PCB testing in existence. The high price reflects that — tens of thousands of dollars, though the cost will depend on board and fixture size, among other factors.To get more news about BT PCB, you can visit pcbmake official website.
An ICT, also known as a bed-of-nails test, powers up and actuates the individual circuitry on the board. In most cases, the test is designed for 100% coverage, but you’ll get closer to 85-90% coverage. The nice thing about ICT is that the 85-90% you get is totally free of human error.
This test involves using fixed probes laid out in a way that matches the design of the PCB. The probes checks the integrity of the solder connection. The bed of nails tester simply pushes the board down on the bed of probes to start the test. There are access points predesigned in the board that allows the ICT testing probes to make connections with the circuit. They put a certain amount of pressure on the connection to make sure it stays intact.
2. FLYING PROBE TESTING
Flying probe testing is a tried-and-true option that’s less expensive than in-circuit testing. It’s a nonpowered type of test that checks for:The test works through the use of needles attached to a probe on an x-y grid obtained from basic CAD. Your ECM programs coordinates to match the circuit board and then runs the program.
We touched on flying probe vs. ICT being a common comparison. Each has advantages and disadvantages.
3. AUTOMATED OPTICAL INSPECTION (AOI)
AOI uses either a single 2D camera or two 3D cameras to take photos of the PCB. The program then compares the photos of your board to a detailed schematic. If there is a board that does not match the schematic to a certain degree, the board is flagged for inspection by a technician.
AOI can be useful for detecting issues early to ensure production is shut down ASAP. However, it does not power up the board and may not have 100% coverage for all part types.
4. BURN-IN TESTING
As the name suggestions, burn-in testing is a more intense type of testing for PCBs. It’s designed to detect early failures and establish load capacity. Because of its intensity, burn-in testing can be destructive to the parts being tested.
Burn-in testing pushes power through your electronics, usually at its maximum-specified capacity. The power is run through the board continuously for 48 to 168 hours. If a board fails, it is known as an infant mortality. For military or medical applications, boards with high infant mortality are clearly not ideal.
5. X-RAY INSPECTION
Also referred to as AXI, this type of “testing” is really more of an inspection tool, at least for most ECMs.
6. FUNCTIONAL TESTING
There are customers who do like a good, old-fashioned functional test. Your ECM uses this to verify that the product will power up.
7. OTHER FUNCTIONAL TESTS
There are other types of functional tests that can be used to check your PCB, depending on the circumstances.
A PCB functional test verifies a PCB’s behavior in the product’s end-use environment. The requirements of a functional test, its development, and procedures can vary greatly by PCB and end product.