Measurement of solder crack rate by cross-sectional observation.

We conducted measurements to reconfirm the temperature of heat generation during curing, following the change to a non-toxic epoxy resin. When using a large amount of resin, we apply heat generation prevention treatment for resin embedding. Without this treatment, the temperature can rise up to 138°C during curing. However, by applying the heat generation prevention treatment even with a large amount of resin, we were able to keep the heat generation during curing within 30°C.

At Aites Co., Ltd., we provide a wide range of technical services for evaluation tests of printed circuit boards (mounted boards) equipped with electronic components. We conduct reliability tests, solder joint observations, whisker observations, and cross-sectional observations. We have IPC-A-610 certified IPC specialists on staff who can assist with observations in accordance with international standards, consultations, and various observation-related concerns. Additionally, we offer services such as X-ray observations, appearance inspections, and shape measurements, so please feel free to consult with us when needed.

We would like to introduce an example of cross-sectional observation of mounted components conducted by our company. Using commercially available computer circuit boards, we observed the solder joints of mounted components and the internal structure of the components with a metal microscope. The observation modes of the metal microscope include bright field observation, dark field observation, and polarized light observation, among others. Additionally, there are observations using transmitted light, and the observation mode is selected according to the sample. By conducting cross-sectional observations before and after reliability testing, we can evaluate the reliability of the product. When observing, it is important to select an appropriate "observation mode" to clearly capture the condition of the solder joint interface and defects such as cracks.

We will introduce examples of cross-sectional observations of various components mounted on a board called an organic substrate. Inside various electronic devices around us, there are substrates equipped with electronic components. When observing the mounted substrate, you can see that numerous components are tightly soldered together. It is necessary to verify that these components are properly joined, as they will not function correctly otherwise. Please contact us if you are considering observations before and after reliability testing or cross-sectional observations.