Homework

Files package: homework files, 20130901.zip. Layout is due on Sunday Oct 10 (2 weeks after the first class meeting).

FAQ

Related to homework

What to do with custom component (*.s) and footprint (*.p) files from the homework package?

Copy the files with the *.p extension (custom PCB footprints) to C:\Documents and Settings\[user]\My Documents\ExpressPCB\PCBComponents_Custom
Copy the files with the *.s extension (custom schematic components) to C:\Documents and Settings\[user]\My Documents\ExpressPCB\SchComponents_Custom
After you do this, restart ExpressPCB and ExpressSCH. The new footprints and components will be available in the component manager dialogs.

About surface-mount components (SMD). Most components in the homework BoM are through-hole, while several are surface-mount. Why?

I have included a few SMDs into homework to encourage you to try your hand in PCB layout for SMDs (and hand soldering them too). Through-hole components are handy for breadboarding, and through-hole boards are easy for beginners to solder. But the through-hole components are gradually fading away in the industry (for the most part). A lot of new ICs are available only in SMD packages. In light of this, it’s good to have hands-on familiarity with SMD. The lab part of this PCB class can help you familiarize yourself with SMD.

You can take this further. If you have room left in your homework board, you can fill it with various SMD pads to practice surface-mount soldering. That would allow you get a sense for which package sizes you can comfortably solder by hand, and which ones are uncomfortably small.

How should I send the completed homework?

By e-mail. My e-mail address in the handout is current. You will receive an e-mail confirmation from me within a day. If you don't receive a confirmation - contact me via e-mail, web group, or other means you can think of. If you get a chance, send me a link-test e-mail beforehand. Another good idea is to quickly follow-up your homework with a short simple e-mail without any attachments. Please don't zip the files. That increases the risk that your e-mail will be filtered out by a spam filter.

Related to ExpressPCB

How do I add a mounting hole to a board in ExpressPCB?

Place a pad (a via) with a sufficiently large hole. EspressPCB creates only plated holes.

If you want to have a non-plated mounting hole, place a via with smaller diameter than the desired mounting hole. Using the via as a drill mark, drill out the mountign hole to the desired diameter with a drill press.

Is it possible to copy and paste from one ExpressPCB file (schematic or layout) to another?

Yes, it's possible. It's just less intuitive, compared to maistream office programs. You can't open 2 separate instances of ExpressPCB and copy from one to another. The workaround is to copy and paste within the same window.

  1. Open the file which you want to copy from.
  2. Select the content that you want to copy, and copy it (press Ctrl+C).
  3. In the same instance of ExpressPCB open the file that you wan to copy to. (Or create a new file, to copy to.) It's important that you don't close this instance of ExpressPCB between copying and pasting.
  4. Paste the content (press Ctrl+V). The pasted content will remain selected. Move it to desired position. Done.

These steps were tested in version 7.3.5 of ExpressPCB.

General

Why is CadSoft Eagle not used in this workshop, and ExpressPCB is used instead? Eagle is available free of charge for education purposes. It’s widely adopted by the maker and Open Hardware communities.

This choice was made primarily because the total period of the class is just 3 weeks. ExpressPCB takes a lot less effort to become familiar with, compared to Eagle. At the same time, ExpressPCB is an adequate vehicle for gaining the fist-time PCB design experience. The goal of the workshop is to provide the introduction to the PCB phenomena and the initial hands-on experience. Using that as a foundation, you can subsequently learn a more advanced design package of your choice.

As an experiment, I have done a dry run of this class with Eagle (the version at the time was 5.4). Three of my friends volunteered as guinea pig students. The results were mixed. A disproportionate amount of students’ efforts went just into figuring out Eagle's user interface.

Can I work on my own design instead of a standard homework project?

That’s possible; however, you have to send a proposal before the start of the class. See request for proposal (RFP).

Office hours

by request

Bibliography

  1. IPC standard IPC-2221 Generic Standard for Printed Circuit Board Design.
    This is a must-read if you want to do PCB layout. Earlier editions from late 1990s and early 2000s should be adequate for designing moderately complex boards.
  2. MIL standard MIL-STD-275E Printed Wiring for Electronic Equipment. 1984
    This is a forerunner of the IPC-2221 standard. I'm referencing it for historic purposes.
  3. Mitzner, K. Complete PCB Design Using OrCad Capture and Layout. 2007
    ISBN-13: 978-0750682145
    The first portion of the book is a general overview of PCB technology, even though the OrCAD tools are mentioned in the title.
  4. IPC standard IPC-2152 Standard for Determining Current-Carrying Capacity in Printed Board Design.

Links

Tips and Tricks

Tips for designing PCBs: http://www.expresspcb.com/ExpressPCBHtm/Tips.htm

PCB design tips and patterns: http://www.robotroom.com/PCB-Layout-Tips.html. These tips are oriented towards beginners and hobbyists. Throughole components.

Message boards, Groups, Forums, Meetups

Dedicated discussion group for this PCB layout class: http://groups.google.com/group/pcbclass

San Jose TechShop holds regular meetups: http://www.meetup.com/TechshopSJ. Electronics and Embedded meetup, Arduino meetup.

ExpressPCB discussion and sharing of libraries: http://tech.groups.yahoo.com/group/ExpressPCB. Point of interest: in the files section of this group there is an ExpressPCB template for Arduino shields.

Discussions about sensors: http://tech.groups.yahoo.com/group/SensorForum

Board assembly houses

There are dozens of PCB assembly houses in the Bay Area. Geographically, the highest density seems to be in the Fremont, Milpitas, San Jose region. Some of them prefer large production runs, others prefer smaller runs. Some of them have specific quality systems needed by medical device or aerospace industries.

PCBA houses, which I have worked with: United Manufacturing Assembly Inc., Zytek Electronics Manufacturing Services, QoSTronics, Inc.