Firstly, let’s clarify that Workingbear is not a metallurgy expert. The content of this article is based purely on personal experience and information gathered from the internet. If there are any errors, feel free to point them out for correction. However, Workingbear takes no responsibility for any consequences.
Have you ever noticed those tiny circles on PCBs and wondered why they’re there? They don’t seem to have any parts soldered onto them, and some don’t even have solder paste. Well, those small circles are called test points, and they play a crucial role in ensuring that the electronics on the PCB are working correctly during the assembly process.
For those who know about electronics, having test points on a PCB is common knowledge. However, for those with a background in mechanics or other fields, the term “test point” might be a bit confusing.
Do you know what ICT (In-Circuit Test) is? Please note that we are not talking about Information and Communication Technology (ICT) here. And what about MDA (Manufacturing Defects Analyzer)? If these tests are commonly implemented in PCB assembly manufacturing, what are their pros and cons? How do they differ from ATE (Automated Test Equipment)?
ICT is primarily used for the electrical testing of Printed Circuit Board Assemblies (PCBA). Think of it as an advanced “multimeter” or an LCR meter. It allows us to test the electrical characteristics and check for open/short circuits of all components on the circuit board without removing them.
In the reflow soldering process of Surface Mount Technology (SMT) in electronic assembly, the occurrence of “Graping” solder defect refers to the situation where the solder paste does not completely melt and joint together during reflow. Instead, individual solder powders gather and stack together, resembling a cluster of grapes.
So, how does this “Graping” solder defect happen? Solder paste is essentially a mixture of tiny solder powders combined with flux. When the flux in the solder paste evaporates, it leaves behind individual solder powders.
In the assembly and soldering process of printed circuit boards (PCBs), we often hear engineers or lab reports mentioning the term “IMC.” But what exactly is IMC? What role does IMC play in the PCB assembly (PCBA) soldering process? Does it impact solder joint strength? People often comment on IMC being too thin or too thick, so what is a reasonable thickness for IMC?
