2012年9月2日 · Placing vias over SMD pads is pretty common and an acceptable practice provided you take good care while designing. Here are some practices I follow when I use Via in Pad: I don't tend to use through hole via in pad for 0201 passives. The pads for an 0201 are pretty small for a through hole mechanical drill and may damage the pad in the process.

2022年1月27日 · SMD pads come in basically two shapes: rectangular and rounded rectangle. Does either offer advantages? For instance for etching, or HF signal integrity?

2012年4月11日 · Which of the three ways shown above would be the best way to short two adjacent SMD pads together, and why? These are TSSOP pads and the assembly process will be lead-free reflow, if that matters. If there are better ways that I have not pictured, feel free to show them too. I can imagine that in terms of impedance, C is best and A is worst.

2022年6月30日 · SMD pads; That works very well. These SMD pads stay attached to the board in spite of the heavy transistors with heat sink because I put in holes inside the pads. So they're SMD pads, but with a via in the middle. You can also put vias in the corners too. The vias take up less space on the other side of the board than a full thru-hole pad.

2014年8月27日 · I agree with @Vladimir that smaller pads can be a pain, and in fact can make the boards hard to inspect because you can't see the fillet easily through a microscope that is vertical. For what it's worth, the solder mask used in a recent board with QFNs used a 0.106mm (4 mils) default (rule-based) expansion factor, which left slightly less than ...

2017年2月5日 · Yes, SMD footprints should have rounded corners as per IPC-7351A. Corner radius is 25% of the shorter side of the pad but not more than 0.25mm (10mil which is not exactly the same but close enough here)

2022年1月26日 · The drawing in the O.P. comes from a datasheet. Some datasheets have a dimensioned drawing for the footprint (land pattern). Here's an example. Notice that the pads (top right corner) a somewhat wider than the legs. Originally from here. Found this by googling SOT-223. SOT-223 is a fairly common package.

2018年1月7日 · What I use to do is put soldering paste on pads (I use a syringe with a very fine needle to apply it, it really doesn't need much), place the component as best as possible. It doesn't have to be 100 % perfect, especially if the board has solder resist, as the reflowing soldering paste will allow the part to align itself a bit, but not too much.

I am working on a 2 layer board and the PCB will be a double sided job. Some components on the top layer will have exact mirrors on the bottom right under them. My question is, for SMD components, can I just connect those pads with a VIA right in the center of the pads? Yes, will the assembly house be happy about it? No.

2021年4月24日 · Here is a side view showing pins above the pads that would need bent down to contact the pads: Here is a top view to show how the pins align with the pads: We found that edge-mounting a TO-Can package to a PCB will really save a lot on manufacturing. However, it comes with fairly long through-hole pins that are taking up too much space.