Big Problems with Testing Small PCBAs

Electronics manufacturers have been busy investing in new production equipment that has dramatically increased the productivity of their assembly lines. New pick and place technology can accurately place tens of thousands of components per hour. When combined with more powerful chips that have been shrinking board designs and reducing component counts, boards have never been manufactured so fast.

For example, a recent 30-up panel of control boards was produced every 45 seconds, so the line was cranking out 2400 boards per hour.

Unfortunately, the traditional test process has no chance of keeping up with modern SMT lines. For this project, the functional test time was 5s / board. But, the manual handling time of 10s / board means that only 240 boards per hour could be tested. Typically, that speed is sufficient for single boards, but, for highly panelized boards, modern production has vastly outpaced test time improvements.

The result is a 10x mismatch between production throughput and test throughput. This is not a bottleneck, it’s the Hoover Dam!

Manufacturers of high volume, panelized boards are experiencing this type of mismatch across a wide variety of small boards, such as connected sensors, automotive electronics, and consumer electronics. CheckSum has witnessed three common responses:

1. Build a large "Work-in-Process" Inventory of untested boards that can slowly be worked down between production runs.
2. Slow Down production to match test throughput.
3. Purchase More Functional Test Equipment and hire additional staff to increase test throughput. In this case, 10 additional stations.

The cost of addressing the mismatch is high. Building up a daily WIP inventory of untested boards also carries risk. CheckSum has heard numerous stories about “that time 5000 untested boards were found to all have the same defect.” How much did that cost to fix? Were production commitments missed?

As many OEMs restrict rework, untested boards can end up being scrapped, hitting a manufacturer’s P&L as well as production schedule. Slowing down the line or buying a lot of standard functional test equipment is extremely expensive.

While the costs of the mismatch are a concern, the quality impacts are generally what our customers are most worried about. When the manufacturing process includes building up an inventory of thousands of untested boards every day, it is just a matter of time before disaster strikes.   

Moreover, manufacturers are utilizing new information tools, such as Industry 4.0, leveraging real-time data and high powered analytics to optimize various processes. The key to these systems is Real-Time Data, yet traditional test processes that do not operate on the manufacturing line and cannot keep up with production can only supply information from several hours ago. Is that the data you want to use to make ‘real-time’ decisions?

CheckSum’s new Parallel Functional Test capability solves the mismatch by enabling high-volume manufactures of panelized boards to keep up with production, eliminate human handling, and provide real-time test data to ensure the manufacturing process is optimized.

Do you enjoy keeping up on industry news and trends? Join our newsletter list for quarterly updates from CheckSum.