pcb fabrication - Removing debris from PCB

I have a PCB with no solder mask with a very dense layout and a very fine trace spacing.I didn't get a solder mask because it's still in the prototyping phase, and it's way cheaper.I keep having to stop, find the new shorts that keep popping up, and remove metal fibers that are barely visible. From what I can tell the fibers are aluminum from the pcb so a magnet is no help.Is there a trick to remove them faster or a way to stop this from happening?...Read more

pcb fabrication - How to evaluate the reliability of a PCB-printing service?

I had a talk with a friend the other day who told me that he had many issues with PCB-manufacturers in China (copying his product, long delivery times, bad quality) and that he had to sell his company because of all these issues.So I wonder: if I want to produce a PCB-board in higher quantities that also require some IP-standards, and needs certification for the european market, how do I know wheter or not the company I'm going to work with is reliable?...Read more

pcb fabrication - PCB Thickness Variability

How much variability is there in the thickness of a standard PCB?Let's say I order a 1.6mm FR-4 board. Will the actual thickness range 1.5mm-1.7mm? 1.4mm-1.8mm? 1.59mm-1.61mm? What is the (approximate) value of x in "1.6mm ± x%"?What if the board is ordered thinner? (say 0.8mm)How does controlled impedance affect this range? It's supposed to specify that the dielectric thickness must be controlled, but how much does it actually reduce the variance? I'm assuming this all varies somewhat by manufacturer, I'm just looking for some reasonable guide...Read more

pcb fabrication - Altium Designer: How do I scale the output gerber file generated by Smart PDF into 1:1 ratio?

I'm trying to export a PCB layout PDF from Altium Designer 13.2.5.When my PCB design is open, I clickMenu > File > Smart PDF...to open the PDF generation wizard. Throughout the wizard, I do the design output settings, and at the end of the wizard a one page PDF containing the PCB tracks, pads and holes is generated, as you see in the image below.However, the page of this PDF is in standard A4 size (210mm x 297mm), my PCB layout is stretched to entire page and the original scaling of my PCB is lost. My PCB manufacturer requires it to be in unit ...Read more

pcb fabrication - Gerber file edits

I'm making my own PCBs at home and I'm using KiCAD to layout the boards and create the Gerber files. From the files I'm making my template which I transfer to my boards and then finish the etching process.I was wondering if there was a way that I can modify the thru holes in the file so that they appear on the Gerber drawing as having a small hole in the middle of them. Currently they show up as a solid pad.The reason is that when I drill out the holes I'd like to have the copper already pitted/removed in the center to make it easier for star...Read more

pcb fabrication - Flat flex cable soldered to PCB is developing a short circuit over time

I'm facing the issue that an OLED display develops a short over time and stops working. The short always occurs at the solder point where the flat flex cable gets soldered to the PCB.Touching the shorted pins with the soldering iron fixes the short and I can use the OLED again but after at least a few hours the pins are shorted again.How can this happen? The OLED was hand soldered. Is there anything specific that has to be done to properly solder these connectors?The short also always appears at the Chip Select and Reset line. This problem occu...Read more

pcb fabrication - PCB Open Via Issue

I am recently bump into a problem where we found a certain percentage fallout of the open via. This is my very first time seeing this kind of problem and don't really have an idea why. It comes back from failure analysis with some images as posted. The first image looks like a corrosions on the copper plating while second image, the copper is totally open. I am checking the via plating thickness and it is within the spec. Some are saying it is caused by the copper plating during PCB fabrication but anyone please advice and explain what could b...Read more

pcb fabrication - PCB layer sequencing

I'm designing a 8-layer PCB. Two layers have been reserved for GND and 2 for various digital supply voltages. Remaining 4 are meant for various signals( mostly serial data, video and USB). How should the layers be arranged to make most sense considering noise immunity? FYI: I decided on 8 layers because in 6 layers I couldn't imagine fitting all my signal traces....Read more

pcb fabrication - Intriguing obsolete(?) PCB manufacture techniques in this old MSX

Browsing Wikipedia (as one does), I have stumbled upon this picture of a circuit board¹:Now, when you look at it, there are several things that stand out as being interesting and different to today's commonly used PCB manufacturing techniques.I don't have access to the board pictured, but here² are some more pictures of it. However I do recall seeing other circuit boards using these techniques; especially on lower-cost devices from the late 80s/early 90s and remote controls.So, here is what I'd like to find more about:Multiple soldermasks?Ther...Read more

pcb fabrication - PCB Panel Size for Maximum Manufacturability

What is a reasonable panel size to choose when ordering panelized PCBs from my manufacturer if I want to be able to get them assembled by as many PCB assemblers as possible (i.e. I haven't decided on which assembler to use yet, and/or I may change to a different assembler in the future).Also, are tooling holes needed on the tooling strips, or are just plain tooling strips sufficient?...Read more

pcb fabrication - Clearance between hole and power plane after removing unused via pads

After removing unconnected via pads and repuring copper fill, the clearance between the via hole and the fill will be defined by the rules, but the pours will be closer to the hole. Does this bring risk when manufacturing vias, especially when drilling?Clarification:Yes, the only guide in this case (as well as many other when making PCB) is to follow PCB manufacturer's guidelines. What made confusion in my case is that the rule which defines clearance between any hole and copper was wrong, so when I remove via unused via pads, the copper comes ...Read more

pcb fabrication - How to create documentation layer at PBC at home

I am making my own PCBs at home with printing on laser printer. Creating copper layer and non-soldering pads is easy, but I would like add documentation layer too and now I am stuck. How do you solve this problem?I can do PCBs like this, but I would like to add the while texts on them too like here Is there an easy way to doo that? Thanks for all suggestions :)EDITI fount thishttps://www.aliexpress.com/item/Super-PCB-UV-photosensitive-inks-white-PCB-UV-curable-solder-resist-ink-solder-mask-UV-ink/32684337516.htmland first test came out good:Fir...Read more