normand

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  1. PCBWay VS OSH Park VS Smart Prototyping I was working on designing a pcb for a new project when I was approached by someone at PCBWay who asked if I was willing to review their pcb service. I said yes and they offered to manufacture and send me the pcb’s for my project for free. The price calculator and ordering system is fully automated on their website, you just fill in the details, you get a price quotation, next you upload your gerber files and place your order. A day later after submitting my files I was contacted by someone who was reviewing my gerber files. After exchanging some emails on those points my order went through manufacturing and I was notified it has been shipped with DHL. About 5 days later I had the boards in my hands and let me tell you these must be the most beautiful PCBs I ever had manufactured. This is mostly due to the nice gold plating and the matte black soldermask. Definitely perfect for making front panels as I intended for one of these pcbs. So let’s go through some things and compare these 3 pcbs. First let’s take a look at the quality of the silkscreen. All three have white silkscreen and I tried to get similar sized text for comparison. All images have been captured under my low cost microscope, at the same magnification level on the same flat bed surface. Unfortunately the pcb from OSH Parkdoesn’t have any silkscreen, I don’t remember why, it was a prototype I did a while ago. The most likely scenario is that I forgot to export the silkscreen layer in my gerber files. In this case, the result is quite clear, much better printing from PCBWay, they seem to have a higher resolution print. Most of you might not care to pay extra just for a better silkscreen but then again there might be some people who are designing for example a front panel pcb which needs a nice higher resolution silkscreen. Next let’s take a look at soldermask alignment. In this category we can compare all three, and let me explain first that, with bigger mask relief (that is the clearance from mask to exposed copper pad) it is easier to handle offsets of the soldermask with regard to the actual copper layer. So I think, manufacturers that can’t maintain a tight tolerance on their mask alignment just increase the relief to make sure the mask never accidentally covers what should be an exposed pad. On this point, PCBWay again seems to be the best, I don’t even know what kind of process they use, but judging from the photos that I could get with my microscope, it looks like the soldermask extends right up to the copper pad with perfect alignment. The spacing between the copper pads is also marked on the image and that is something to consider because with very low spacing some manufacturers cannot guarantee soldermask in between those pads. Having no soldermask in between pads might affect your soldering quality, you might get solder bridges more often for example. And in this test, the pcb from Smart Prototyping doesn’t get any soldermask in between those pads. Next, let’s take a look at via/hole registration. This becomes quite important when working with small drill sizes like 0.3mm and below. You want your pcb to have that hole drilled right in the middle of the pad/via to ensure even copper distribution around it. Starting from the left, we have PCBWay with a 0.5mm drill via, with excellent registration, clearly the winner judging by the even copper surface all around the drill hole. Next we have OSH PARK with 0.3mm tinted via, very good registration, no problem at all. And on the right we have Smart Prototyping probably 0.4mm drill tinted via, with a small offset. So to conclude my experience with PCBWay, their website is great, you get all the info you need there and the process of ordering is very streamlined. Their customer support was very professional, not wasting time at all and the pcb quality was superb, the pictures speak for themselves.