Printed Circuit Board Electrical Testing
SDY 100% performs electrical testing on all printed circuit boards to ensure their quality. Below is explanation of how these tests are performed and what they mean. SDY has its own factory with manufacture facilities and testing equipments. Your order is manufactured by us and tested by us so you can know that your printed circuit boards are free of defects and meet the standards you required.
Currently there are two different types of electrical testing, flying probe test and fixture test. Flying probe test machines are fixtureless testers and usually suitable for small quantity orders. It doesnot require any special tool or fixtures, so the cost is smaller for small quantity orders. But it takes much time for test, as it is tested point by point, or net by net. It has extra time and labour cost. So the flying probe test is required every time for orders. Fixture test, or E-fixture test, requires a special fixture or tool for a specific model of printed circuit board. These machines use fixtures built specifically for your PCB. The fixture can be used in repeat order, and can test a panel boards in one time. So the fixture charge is paid one time only, and no more electrical test charges in repeat orders. Below is a comparison of two types of electrical testing.
| Features | Flying Probe Test | E-fixture Test |
| Efficiency | Lower | Higher |
| Time | More | Less/Faster |
| Charge | Needed every time | Paid one time only(NRE) |
| Suitable orders | Small orders, samples, prototypes | Large orders, repeat orders |
Bare board testing involves capacitance and resistance tests, and each of our machines uses a combination of both. Capacitance testing for a bare board involves testing for opens and shorts by "charging" a net or plane and then probing each net to measure the induced capacity. Inaccuracies occur with this method because of the inherent variability in producing circuit boards. However field measurement or field effect testing for shorts uses a very similar approach.
Resistance testing measures the resistance found in the net. As electric current flows through a conductor collisions between electrons and atoms interfere with the flow of the electrons. This is known as resistance and it's measured in ohms.
A good conductor has LOW resistance - at common temperatures silver is the best conductor and copper is second. The amount of resistance depends on the conductor's length and its cross-sectional area. If you have two circuits of the same material and the same cross-section and one is twice as long as the other - the longer one has TWICE as much resistance. If you have two circuits of the same material and the same length but one is twice as thick as the other - the thicker conductor will have HALF the resistance.
So Resistance is proportional to length and inversely proportional to the cross-sectional area of a conductor and dissipates power in the form of heat.
SDY follows the IPC 9252 specification guidelines for Class 2 testing processes, which means that we test 100% of the networks on the board for continuity and isolation (that's opens and shorts) using a test program generated from your Gerber data.
SDY manufactures quality PCBs according to customers’ design and data. Kindly please feel free to contact Alex@sdy-pcb.com or our engineers for any PCB questions or RFQs.