PCB category

Panelizing made easy in Eagle

Sjaak shared a tip for panelizing PCB boards in Eagle:

Panelizing is done by machining a slot between two or more boards, but keep them attached by a small amount of PCB material (mousebites). I used to do it by hand: generated all the schematics into multiple sheets and then route the board and finally add the slots with mousebites in the PCB editor. I generally use slotwidth of 50 mil and the smallest drill possible (12 mil) 12.5 mil apart as breakingline. I tend to place the mousebites about 2cm from each other to maintain PCB strength.

Panelizing made easy in Eagle – [Link]

Circuit Board Design for Beginners

By: Alex Danovich,President San Francisco Circuits

We live in an exciting time where we see a resurgence in electronics as a hobby. Mass production has wiped out a generation or two of kids learning to build radios from scratch with their mom or dad. In the good old days, not sure when, you had companies like Heathkit walk you through building a full size color TV at home, for example. “Yes, I made that!” you’d proudly exclaim to yourself after hours of work.

What’s causing this hobbyist resurgence?

  • Television shows such as How it’s Made, Mythbusters and other programming on TLC.
  • Websites such as instructables.com, hackaday.com, and specialized hobbyist blogs.
  • Interest in RC cars, robotics, gaming, computers etc.
  • Advent of Arduino boards, modules and free software.
  • Open source software/hardware.
  • The whole maker movement in general.

So what does this have to do with making circuit boards?

Well, it’s now easy and fairly cheap to make a nice circuit board for your project without a lot of fuss. So you want to get the kids away from the TV and build a fun, blinking LED project for your kids? Gone are the days of tedious hand wiring, empty coffee cups, smoking components and unprintable words; they’re now replaced with easy online applications.

In times past, I would sketch out a circuit on a raw copper board using a Sharpie pen. Then I dipped it in a bath of some nice toxic Ferric Chloride from Radio Shack and waited and waited. After a long while, you removed the board and then hand drilled the work of art. To prevent corrosion, you rubbed some silver powder on it. Finally, stuff the board and there it is. Your mom (or wife) is now furious over the stains, mess and the stink you just created. But there it is. You let out a great sigh of personal satisfaction.

Fast forward to post-dinosaur times.

The Steps to Glory

  1. There are several good choices for a free schematic and circuit board design program. I prefer Eagle. Lots of hobbyists and pros use it so there are lots of free designs and tutorials available. The free version is somewhat limited but very useful for smaller work. What’s nice is that if you like this as a hobby, you can progress to the “pro” version.
  2. Next you will have to find a “board house” to make the boards. The author of this article is a good place to start for a free quote – San Francisco Circuits.  SFCircuits is a full service PCB fabrication and PCB assembly provider  from hobbyist to military grade work with some helpful tutorials in the PCB School section. Who knows – you just might go from blinking LED project one day to a nice ICBM with them. Impress the neighbors?
  3. Once you have a board on its way, consider it time for buying assembly parts from Digikey or Mouser. They are great distributors and cater to hobbyists with smaller quantities with good pricing. It’s so much better than Radio Shack which carries less and less useful components lately. However, you must be careful buying integrated circuits, resistors, capacitors, etc. online as they come in a dizzying array of sizes.

Design Considerations

  1. Sketch out on paper what your PCB will look like.  Do you need holes for mounting? Do you have a box in mind? You can get a nice plastic case with battery compartments from Pactec. Did you leave room for connectors to stick out? Make sure you leave clearance for taller components. Part of the trick is to visualize all the pieces and how they fit. Make sure you have clearance for your soldering iron as well.
  2. It’s best to do a single-sided circuit board. You have connection traces between the components on the top side only. A double-sided board can get complicated for first timers. For sensitive analog and high speed digital circuits, consider adding a ground place area on the backside.
  3. Once your layout is done, a critical step is to verify every trace. Adding jumper wires later is not fun. The traditional method is to print the schematic and start in one corner with your favorite highlighter color. Verify every line. A very important thing to remember is that some schematic packages hide the chips’ power lines for clarity. So you may have chips with no power.

An alternate method is to create a “netlist.” This is a point to point list of every connection (more highlighter). A really smart thing is to allow the layout software (if it supports it) to do an automated netlist check. It will give you a list of all the errors, a much faster solution. I like to do some of the manual method as a sanity check to make sure all is well. There is a lot to think about. Some places sell scrap boards to check your soldering skills or to make art out of other folks’ mistakes. Do your best to avoid it.

So cross your fingers, say your prayers and away you go.

Now aren’t hose blinking LEDs pretty cool?

“Yes, I made that”.

This article was written as a guest post by San Francisco Circuits, a PCB solutions provider located in Northern California.

Layout software eases 3D prototype production

2016-10-24-eete-jh-beta

A manufacturer and service provider for PCB prototyping, Beta LAYOUT has developed a 3D MID CAD program to speed up the prototyping and small-series manufacturing of 3D Mechatronic Interconnect Devices (MIDs). by Julien Happich @ edn-europe.com:

Circuit carriers of the three-dimensional circuit boards are produced at Beta LAYOUT using 3D printing. This eliminates the need for costly injection moulding dies, as commonly used in series production. After this, the MID components are processed on a special production line using laser direct structuring, and then assembled.

Layout software eases 3D prototype production – [Link]

Creating footprints in KiCad using a scanner

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Jan @ jasiek.me decided to use a flatbed scanner to trace out a footprint in KiCad. [via]

Some time ago I sourced a number of very cheap SD card sockets from China for a hobby project I was working on. Sadly, when it came to PCB design, I couldn’t find the footprints for this particular socket anywhere – the part being a proprietary invention of the factory rather than a cheap knockoff of a reputable brand like Amphenol or Molex for which drawings are readily available off of snapeda.com.

Creating footprints in KiCad using a scanner – [Link]

Exploring Eagle CAD ULPs #4 – Renumber The Parts Number In Order

SnapEDA launches on-demand PCB symbols service

snapeda

SnapEDA launched a new on-demand PCB symbols service. Get any schematic symbol and PCB footprint delivered in 24 hours. Just $29

SnapEDA follows IPC-7351B standards for its footprints, and a combination of IEEE-315 and its own standards for symbols.

All models are created by our component engineering team and verified using proprietary patent-pending verification technology as part of a three-step verification process.

SnapEDA launches on-demand PCB symbols service – [Link]

Exploring Eagle CAD ULPs #3 – Teardrops.ULP Make A Teardrop Shape Connection With Pads and Vias

Welcome to the third post of the “Exploring Eagle CAD ULPs” series. Every week we will publish a new post about one useful ULP in Eagle CAD.

“ULP” User Language Program is a plain text file which is written in a C­-like syntax and can be used to access the EAGLE data structures and to create a wide variety of output files. You can consider it like a plug-in for Eagle.

You can reach the posts published in this series using the following link.

ulpserpost3

In this post we are going to explore a ULP called ‘Teardrops.ULP’. This ULP makes a teardrop shape connection between the traces and the vias or pads.

Before I found this ULP, I thought that I can’t do the teardrop thing using Eagle CAD, while I saw a lot of designs that have been done using Altium have this feature.

Using teardrop shape connection may result in many advantages:

  1. It prevents drill breakout due to drill misalignment where the trace joins the via or through hole.
  2. It makes stronger connection between the traces and the pads. Thermal expansion when re-soldering/desoldering could sometimes lead to a loose connection where the trace joins the pad.

 

Image Source - Youtube/Premier EDA Solutions
Image Source – Youtube/Premier EDA Solutions

 

Image Source - Youtube/Premier EDA Solutions
Image Source – Youtube/Premier EDA Solutions

This ULP should be used with forethought or on a copy of your board file just before plotting because it would be difficult to remove teardrops afterwards. Once added, they can’t be undone using ctrl-z.

Teardrop.ulp GUI
Teardrop.ulp GUI

In the GIF below, I tried to demonstrate how to use this ULP.

teardropulp

Note: You don’t need to download and add this ULP. it’s available in the ulp directory.
To use it, just press the ULP icon from the tool-bar and search for ‘teardrop.ulp’.

Exploring Eagle CAD ULPs #2 – ‘Unrouted.ULP’ Zoom To The Last Left unrouted Wire

Welcome to the second post of the “Exploring Eagle CAD ULPs” series. Every week we will publish a new post about one useful ULP in Eagle CAD.

“ULP” User Language Program is a plain text file which is written in a C­-like syntax and can be used to access the EAGLE data structures and to create a wide variety of output files. You can consider it like a plug-in for Eagle.

You can reach the posts published in this series using the following link.

ULPSerPost2

In this post we will discover “Unrouted.ULP” by Daniel Mack. The job of this ULP is to zoom to the first unrouted wire in the board editor. This might be helpful when searching for tiny leftover air wires especially in big boards.
When we use ‘ratsnest in layout editor, a result with remaining airwires is shown in the bottom of the editor. Sometimes airwires are not visible to our eyes and need a lot of searching.

One Airewire Is Left - See the red circle
One Airewire Is Left – See the red circle

“Unrouted.ULP” can zoom to unrouted line and solve this problem for us.

You can see this ULP in action in the below GIF

unroutedulp

You can download the ULP from here: Unrouted_ULP

That’s all for this time, see you next post in this series!

Tracespace Online Gerber Viewer (beta)

nixie

This particular PCB viewer takes your Gerber and drill files and gives you individual layer renders as well as very fancy renders of what your completed boards are going to look like.

The tracespace viewer accomplishes all this locally (nothing gets sent to any server!) by converting your files to SVGs. Thanks to the “Scalable” and “Vector” in “SVG”, the renders are easy to examine and quite accurate.

Tracespace Online Gerber Viewer (beta) – [Link]

Exploring Eagle CAD ULPs #1 – PickUp.ULP Select Components Both in Schematic And Layout

EagleUlpSeries

Welcome to the first post of the “Exploring Eagle CAD ULPs” series. Every week we will publish a new post about one useful ULPs in Eagle CAD.
“ULP” User Language Program is a plain text file which is written in a C­-like syntax and can be used to access the EAGLE data structures and to create a wide variety of output files, you can consider it like a plug-in for Eagle.

You can reach the posts published in this series using the following link.

ULPSerPost

When we work on schematic design, we always add parts here and there, adding a missed capacitor for a power pin of a regulator or a missed resistor for a data line and so on.
When we will generate the board file to start routing, we will find the parts scattered in the board.

The first rule in placing and routing in PCBs is to place connected components near to each other, but in the raw board file you will find every component located in a different place according to the order of adding them in the schematic.

This becomes very annoying in big designs. You need to gather the connected components manually, you will using MOVE tool for that. For example, to gather the components C9, C11, Y1 and R1 of a crystal connected to the MCU, you should run the following commands in the layout editor:

MOVE C9;
MOVE C11;
MOVE Y1;
MOVE R1;

Some MCUs have up to 50 capacitors and resistors or more connected to them, so obviously gathering components manually is not the way.

Personally I was doing the gathering process manually until the day I told myself, SHOW tool can highlight the component or components (by selecting them using ctrl+SHOW tool) both in schematic and PCB editor, you should find a similar way.

When I googled about the problem I found an ULP (made by lorenznl) in a response of one of Element14 forum discussions “How can I select components booth in schematic and layout at the same time?”, it was exactly what I was looking forward.

To use this ULP, you must select a group of components using GROUP tool then run “PickUp.ULP” from the schematic editor. Now when you will go to the layout editor, you will find the components you grouped them in the schematic editor movable as a group in the layout editor.

The below GIF demonstrates how this ULP works.

PickUpULP

 

You can download the ULP from here: PickUp_ulp

See you in next post in this series with another useful ULP.