Whilst the construction of wafer bumps take many forms testing their quality by bond testing requires either pull or shear testing. Shear testing has the advantage of being easier than pull testing and when it produces the failure mode of interest it can be a good choice but in most cases pull testing is more likely to produce a bond failure rather than a failure in the bulk material of the bump.
Up to 4 USB Tweezers in 1 RMU
To ensure the very best pull test data the many different types of bump construction and sizes require different tweezer jaws. xyztec’s unique 6 head Revolving Measurement Unit (RMU) can take up to 4 CBP or tweezer test heads making it ideal for such applications. You do not need to use all 4 for bump pull testing and any spare positions can be used for any other test with any other tool.
Having the test heads permanently set up on the machine and ready for immediate use improves efficiency and reduces the risk of damage when manually changing heads/cartridges.
More and more of xyztec’s Sigma bond testers are being used for fully automatic testing. The RMU with its ability to have 6 test positions with any sensor and tool configuration is an essential requirement and make it the most capable in the market. The Sigma RMU is also Quick Release allowing more than one to be configured for different test applications with safe production change over in seconds.
Cleaning shear tools and Cold Bump Pull jaws
In addition to having the largest number of test heads automatically available, automation is only possible when any test debris stuck to the sample or tool can be removed. This keeps the sample and environment clean, and the tool or jaws clean ready for the next test. The Sigma accomplishes this with a combination of two cleaning options. The first is located at the test position and uses a pulse of high-pressure air from a small precision nozzle to dislodge the debris from the sample or tool. Once dislodged the air jet blows the debris directly into a large vacuum pipe ensuring its collection.
Solder bump pull
In the case of solder bump pull solder often remains stuck in the tweezer (CBP) jaws, and is very hard to remove. For this xyztec use their patent-pending CBP Jaw Cleaner. Similar to the cold air system a small and precise air jet is used but it is heated to a controllable temperature set to melt any solder stuck in the jaws and then blow it into a fine matrix where it is absorbed.
As the system uses hot air the jaws are automatically driven to a cleaning station which is at a safe distance from the sample and test position.
CBP Jaw Cleaner Station
How to test bonds
We currently offer how-to’s on Cold Bump Pull (CBP) and Wire Pull and we intend to expand it into other test types as well in the future. Additionally, you can find the text of all MIL-STD-883 standards relevant to bond testing in accessible HTML format on our website.