PCB Tech - PCB circuit board distributed test scheme

Software tools for testability analysis during PCB design allow test engineers and designers to work together, thereby shortening time to market.

The general development direction of electronic technology is that products are becoming more and more complex and smaller and smaller, which will increase the number of I/Os and the density of circuit boards. Nowadays, it is not uncommon for the number of solder joints on a circuit board to exceed 20,000. At the same time, the complexity of the assembly process is also increasing. PCB circuit boards often go through double-sided SMT assembly, manual assembly, wave soldering, press-fitting, and mechanical assembly. Process. Although manufacturers are working hard to increase production capacity and reduce defects, they find it difficult to reduce the number of defects on the circuit board.

Software tools for testability analysis during circuit board design allow test engineers and designers to work together, thereby reducing time to market.

If engineers can predict the distribution of faults before the layout of the PCB design, plan the test plan, and understand the trade-off between fault coverage and test access, they will have a great competitive advantage and fundamentally make the design Fewer iterations, fewer difficulties, lower production test costs, higher manufacturing efficiency, and shorter time to market.

In addition to using software tools that can perform testability analysis during circuit board design, manufacturers are also looking for other test solutions to reduce test development time, speed up the introduction of new equipment, and provide a high level of fault coverage and judgment in the early stages of manufacturing. Resolution.

In addition, the sooner PCB manufacturers can meet consumer demand for new products, the more they can win market share and profits. Increasing output in a cost-competitive environment requires effective detection and suppression of defects at the source, and finding out the root causes of defects, as well as greater production capacity.

For specific circuit boards, if the distributed test program can well balance various factors, including diagnostic resolution, fault coverage, testability, test development time, required technical level and training costs, working hours and utilization Condition and cost and output, etc., this kind of scheme can make the test obtain the good result.

How to develop the optimal PCB distributed test program? Since each test method has a different level of performance in terms of different measurement characteristics, it is unimaginable to evaluate all combinations. To solve such a complex problem requires modern software analysis methods. If there is no effective quantitative analysis, and different test methods have many options and have complex and overlapping characteristics, it will be very difficult and time-consuming to obtain an optimized test method. And it is very likely to lead to problematic results.

The above is an introduction to the distributed test scheme of PCB circuit boards