“Solder preforms” are tiny pieces of solid tin alloy that are already shaped before use. They come in two types of flux contain and flux free. These preforms can be put in certain pads to increase the amount of solder paste. This helps when the solder paste volume is constrained due to the limitation of stencil thickness. It makes the solder joints stronger and better, and it also helps to improve voids in the solder.
What are SMT and SMD? The difference between SMT and SMD is that SMD (Surface Mount Device) refers to an electronic component mounted on a PCB using SMT (Surface Mount Technology).
What do we mean by “SMT (Surface Mount Technology)” or “SMD (Surface Mount Device)” for the electronic manufacturing services industry? Workingbear never really thought about this question before, but since someone asked, it means there are still people out there who don’t know. So, let’s take a moment to talk about them. If you’re already familiar with this industry, feel free to skip this article.
OSP (Organic Solderability Preservative) is a special chemical coating applied to the surface of copper on a PCB (Printed Circuit Board). This coating forms a thin protective film that keeps the bare copper from rusting or corroding when it’s stored. During PCB assembly, the coating can be easily removed by certain chemicals, exposing clean copper for soldering.
The OSP coating is like an invisible film, and you can’t see it easily with your eyes. Experts might use special techniques to check if it’s there. The challenge for PCB manufacturers is that OSP-finished PCBs look similar to regular bare copper boards, making it harder to inspect.
WorkingBear has noticed that many engineers or managers involved in Surface Mount Technology (SMT) have a strong passion for “PCB baking,” but their understanding of the concept might not be very clear. If you browse through discussions on PCB and SMT related forums, you’ll often find people treating “PCB baking” as a magical solution to struggle the soldering and quality issues. They believe that pre-baking PCBs before SMT can improve solderability, wetting performance, and the height of solder fillet. But is that really the case?
If you ever get the chance to hold a printed circuit board (PCB) in your hands and take a closer look, you’ll notice there are many different-sized holes. When you hold it up to the light, you’ll even see lots of tiny holes that let the light shine through. These holes aren’t just there for looks – each one serves a specific purpose. Generally, the more holes locate on the PCB, the more expensive it is to make the PCB.
