At Bittele Electronics, we guarantee 100% electrical testing on all PCBs that leave our facilities.We make this guarantee in order to ensure both the quality of our work and the satisfaction of ourclients. Electrical testing, in the world of PCB manufacturing, is the process of checking the electricalconductivity of a finished PCB against the NETLIST file that was defined during the project’s designstages, before the PCB layout was created. Using the NETLIST from the design stages offers protectionnot only against discrepancies which may occur during production, but also against those which mayoccur during PCB layout or Gerber file generation.

The Flying Probe Method is a type of electrical testing that is largely reserved for small-volumeproduction. During this procedure, electro-mechanically-controlled test probes are moved through theboard, testing for expected electrical values at various predefined test points, in sequence. This testingmethod has existed nearly as long as the more well-known “Bed of Nails” In-Circuit Test (ICT), but it didnot enjoy widespread industry adoption until the early 2000s. Low-cost and open-source PCB designsoftware was beginning to allow for smaller businesses and even hobbyists to design boards forprofessional production. Meanwhile, professional designers were looking for a cost-effective solution forthe fabrication and assembly of their prototype runs.

The largest barrier to low-cost, low-volume PCB fabrication and assembly was the cost ofdesigning and building a fixture to be used during ICT. A unique fixture must be created to test each newPCB design, and these fixtures can present complex devices which incorporate numerous preciselyplacedtesting and tooling pins. The time and resources required for PCB manufacturing facilities to buildthese fixtures, relative to the number of PCBs being assembled, is simply not viable for many designers.

This untapped corner of the market, not being served by the industry at large, prompted manyfacilities to take a second look at the Flying Probe’s possible advantages.

The Flying Probe offers a superb solution for low-volume production by eliminating the cost offixture design and production from the equation. Though each individual board test may take marginallylonger using the Flying Probe, the time savings incurred by avoiding fixture creation will more thancompensate for this fact, so long as order quantity remains low. The removal of fixture cost from lowvolumePCB assembly services has opened the market to many new avenues, and the widespreadadoption of Flying Probe testing has allowed for some additional benefit in terms of functionality aswell.

In addition to its advantages in terms of price and time requirement, this procedure also offerssome functionality that cannot be achieved by the “Bed of Nails” ICT. First of all, the probes are capableof making precision connections at a tighter pitch than the ICT is able to achieve. High-accuracy flyingprobes boast an incredible electrical test pitch of 0.1mm, compared to the standard ICT’s 0.5mm pitch,allowing for greater coverage on small and/or HDI (High-Density Interconnect) PCBs.

The Flying Probe can also employ automated optical inspection (AOI) to allow for some specifictests that are not possible using a Bed of Nails. AOI-assisted Flying Probes can catch polarity reversals,low-value components, and individual components in parallel; none of these tests can be performedusing a standard ICT fixture.

At Bittele Electronics, we offer both Flying Probe and “Bed of Nails” ICT electrical testing, andour expert staff will work with you every step of the way to determine the best fit for your particularproject. For low-volume and prototype assembly projects, we are happy to offer Flying Probe testing tosave you those fixture costs. For some high-volume projects, you may want a Flying Probe test to beperformed in addition to the ICT for added functionality, and in this we are also happy to oblige.Depending on the specifics of your design and the quantity of your order, as well as your own personalpreference, we will select the most cost-and-time-efficient method to ensure the quality and accuracy ofevery PCB that leaves our facility.

Related Articles:

• Manufacturing Defect Analysis (MDA) Testing
• Bittele's Essential Design for Testing (DFT) Tips for PCB Assembly
• Bed of Nails PCB Testing
• PCB Netlist Files and Their Use in Printed Circuit Board Fabrication
• PCB Electrical Testing