Proper testing procedures are the key to manufacturing high-quality printed circuit boards. In-circuit testing, in particular, is utilized at the end of the manufacturing process to verify that every board is fully functional. If you are new to the world of PCB manufacturing, you may be aware of the importance of this type of PCB testing without being familiar enough with the industry to determine whether or not your PCB manufacturing partner is well-equipped for thorough In-circuit testing. Fortunately, SMG will walk our customers through the basics of in-circuit testing below, setting up our customers for success.
The Basics Circuit Board Testing: Bed of Nails Testing
When becoming acquainted with the ins and outs of in-circuit testing, you will quickly come across the term “bed-of-nails testing.” As the primary electric testing fixture required for in-circuit testing, a bed of nails tester is one of the most critical components to understand when learning about the basics of PCB testing. The way that bed of nails testing works is by implementing a laminated sheet of epoxy glass over the printed circuit board and placing a number of tooling pins into testing points. Because the pins are connected by wires to a measuring unit, bed-of nails is capable of testing for shorts or other faults within the board design.
The Basics Circuit Board Testing: Fixtureless Circuit Board Testing
While bed of nails testing is a common method of in-circuit testing, it is certainly not the only method available for manufacturers to take advantage of. While bed of nails testing is a procedure that requires specialized fixture tooling, fixtureless circuit board testing exists in the form of flying probe tests.
Rather than use numerous testing pins, Flying probe tests work by moving one or more probe tools across a printed circuit board. While this process is typically an automated one, operating along a two-axis system, flying probe testing is at a disadvantage as it concerns speed. However, while fixtureless circuit board testing is a slightly slower process, flying probes are advantageous because they leave the printed circuit board unmarked from the testing process, unlike bed of nails testing.
Interestingly, flying probe tests are more commonly combined with other circuit board testing features, providing manufacturers with a way to incorporate more comprehensive quality assurance measures into the circuit board testing process.
Designing for In Circuit Board Testing
Regardless of the chosen method of in-circuit board testing, there are design steps that can be taken to optimize the process. For example, when possible, it is wise to avoid designing boards with limited probing access, especially where double-sided printed circuit boards are concerned. By prioritizing accessibility for circuit board operators, it allows for a quicker and easier testing process, which in turn allows the manufacturer to deliver the finished products to your facility with quick turnaround. Unsure of how to limit the density of your printed circuit boards to optimize design for testing? SMG’s experts are available to walk you through the more complex steps of board design to ensure you receive the highest quality service available!