How to make a PCB for my minature Robot
Archiver
Posts: 46,084
How to make a PCB for my minature Robot
Hello,
I'm at a point where I'd like to make PCB for my minature robot. Presently, it has three 1" x 1" Radio Shack general purpose PCBs stacked one above the other using some spacers. I have 30 day trial version of the Protel's s/w. I guess my question is many fold:
······· 1.····· How to tell Protel the dimensions of my board
······· 2.····· After done drawing, how do I go about making the pcb - with steps involved.
I know most of you guys have a lot of experience doing PCB stuff - if you can throw some light and point me to some text (or web site) explaining the process, that'll be really great!!!
Thanks in advance
nagi
Hello,
I'm at a point where I'd like to make PCB for my minature robot. Presently, it has three 1" x 1" Radio Shack general purpose PCBs stacked one above the other using some spacers. I have 30 day trial version of the Protel's s/w. I guess my question is many fold:
······· 1.····· How to tell Protel the dimensions of my board
······· 2.····· After done drawing, how do I go about making the pcb - with steps involved.
I know most of you guys have a lot of experience doing PCB stuff - if you can throw some light and point me to some text (or web site) explaining the process, that'll be really great!!!
Thanks in advance
nagi
Comments
I can't answer question number 1 since I'm not familiar with the software you're using.
As for number 2, there are a few ways of producing your own PCB, I find the following to be ideal if you're only going to make only one board.··Get a PCB with a layer of copper on one side, then you need to etch the tracks onto the copper side of the PCB (following the output of your software which will have drawn out the tracks for you).· Radio Shack carries different materials to etch the tracks, you can get special felt tip pens (they are good for filling in areas) but not so good for drawing straight lines, and are generally too thick to draw tracks which need to go between IC pins.·What I find best are the Dry-Etch Transfer sheets,·you just place them over the copper side of the PCB and with·a pencil you just rub off the portion of the transfer which you want to place on the PCB.· Once your PCB is all drawn which is a very laborious task if you have a big PCB to make up you·place the board into a solution·(ferric chloride)·which eats up all the exposed copper, then when it's done (10 to 15 mins) you wash the board and you can remove the etchings and·drill the holes.
Radio Shack carries all of what you need (including a small manual drill) and I believe they even have a kit with everything you need in it.· Before starting on the robot's PCB, I suggest you practice on some scrap PCB just to get a feel for it.
Alex
Original Message
From: nags [noparse][[/noparse]mailto:nags@crosscity.com]
Sent: Saturday, September 30, 2000 5:00 PM
To: 'basicstamps@egroups.com'
Subject: [noparse][[/noparse]basicstamps] How to make a PCB for my minature Robot
Hello,
I'm at a point where I'd like to make PCB for my minature robot. Presently, it has three 1" x 1" Radio Shack general purpose PCBs stacked one above the other using some spacers. I have 30 day trial version of the Protel's s/w. I guess my question is many fold:
······· 1.····· How to tell Protel the dimensions of my board
······· 2.····· After done drawing, how do I go about making the pcb - with steps involved.
I know most of you guys have a lot of experience doing PCB stuff - if you can throw some light and point me to some text (or web site) explaining the process, that'll be really great!!!
Thanks in advance
nagi
explains how I built a PCB lab for $300 that let's me design 4" X 6" PCBs
for less than $4.00 a piece. These are single sided and very good quality.
The BS/L boards I'm sending out are built with this system.
Paul
Thanks Alex. I shall experiment.
Original Message
From: Alejandro Fubini [noparse][[/noparse]mailto:alex@fubini.freeserve.co.uk]
Sent: Saturday, September 30, 2000 4:26 PM
To: basicstamps@egroups.com
Subject: RE: [noparse][[/noparse]basicstamps] How to make a PCB for my minature Robot
I can't answer question number 1 since I'm not familiar with the software you're using.
As for number 2, there are a few ways of producing your own PCB, I find the following to be ideal if you're only going to make only one board.··Get a PCB with a layer of copper on one side, then you need to etch the tracks onto the copper side of the PCB (following the output of your software which will have drawn out the tracks for you).· Radio Shack carries different materials to etch the tracks, you can get special felt tip pens (they are good for filling in areas) but not so good for drawing straight lines, and are generally too thick to draw tracks which need to go between IC pins.·What I find best are the Dry-Etch Transfer sheets,·you just place them over the copper side of the PCB and with·a pencil you just rub off the portion of the transfer which you want to place on the PCB.· Once your PCB is all drawn which is a very laborious task if you have a big PCB to make up you·place the board into a solution·(ferric chloride)·which eats up all the exposed copper, then when it's done (10 to 15 mins) you wash the board and you can remove the etchings and·drill the holes.
Radio Shack carries all of what you need (including a small manual drill) and I believe they even have a kit with everything you need in it.· Before starting on the robot's PCB, I suggest you practice on some scrap PCB just to get a feel for it.
Alex
Original Message
From: nags [noparse][[/noparse]mailto:nags@crosscity.com]
Sent: Saturday, September 30, 2000 5:00 PM
To: 'basicstamps@egroups.com'
Subject: [noparse][[/noparse]basicstamps] How to make a PCB for my minature Robot
Hello,
I'm at a point where I'd like to make PCB for my minature robot. Presently, it has three 1" x 1" Radio Shack general purpose PCBs stacked one above the other using some spacers. I have 30 day trial version of the Protel's s/w. I guess my question is many fold:
······· 1.····· How to tell Protel the dimensions of my board
······· 2.····· After done drawing, how do I go about making the pcb - with steps involved.
I know most of you guys have a lot of experience doing PCB stuff - if you can throw some light and point me to some text (or web site) explaining the process, that'll be really great!!!
Thanks in advance
nagi
circuit board program,make yourself a board on screen,then print that board
to any printer onto a transparency,use the smooth side of the transparency.
Inkjets work fine. Print it in reverse mode. Get yourself some acid and
cleaner for pre sensitized boards. To get the traces onto the board. I lay
the circuit board on a table,place the transpacerency over that,then a sheet
of thin glass to hold it down. Over that I place a desktop flourescent
lamp,mine is a F15 bulb. Just a standard flourescent tube nothing fancy. I
place the bulb 3 inchs above the board,and allow it to burn for 20
minutes.This time is for a 2x4 inch board.
Then place the board in your developer and rinse off all the green
resist,there will remain very faint green traces(hard to see with naked
eye),when done wash it under tap water.
To etch I used a large oilpan filled with hot tap water,in that I have a
coolwhip container which I place my ckt board. I then put the acid in the
coolwhip container and swish it around for about 11 minutes. The warm water
around the small container helps to keep the acid warm while it is etching.
I noticed that a black oily stuff forms onthe board initially,as you keep
swishing the board it will go away and the acid will start to etch. You will
notice copper disolve from the outside of board working inwards.
I just held the side of the coolwhip with my fingers and kept a slow steady
swishing motion. Or clamp some visegrips onto the container to keep from
splashing your hand.
When done rinse the board off.
I have made .1 thick traces with this method many times. I have noticed
that your printout must be perfect, you cannot see any breaks in the traces
on the printout or they will show up when etched. You could go over a minor
spot with a black pen for touch up,before etching.
I printout in solid black color, and I use the ExpressPCB free program to
make my circuits I have to route everything by hand,but thats not so bad for
smaller circuits.
If you need help with that program please write me,there are some tricks to
using it.
When you buy the acid and etchant it will say on the bottle what ratio to
mix them.
I have used the same mixed acid and etchant now for 5 differant boards,and
it still seems to work fine. a little goes a long ways.
Sincerely
Kerry
Admin@M...
WWW server hosting
[url=Http://mntnweb.com]Http://mntnweb.com[/url]
Binghamton online Webcam [url=Http://MntnWeb.Com/bing.htm]Http://MntnWeb.Com/bing.htm[/url]
CHRISTMAS Web Page [url=Http://mntnweb.com/xmas.htm]Http://mntnweb.com/xmas.htm[/url]
--So you think you need more memory... the LEM went to the moon on 16K,how
much do you REALLY need?
I just finished using http://www.expresspcb.com/·for a small run of boards.· If you only need a few it might be better than doing it yourself.
--
Richard Clemens
clemens@wvwc.edu
Original Message
From: nags
To: 'basicstamps@egroups.com'
Sent: Saturday, September 30, 2000 5:00 PM
Subject: [noparse][[/noparse]basicstamps] How to make a PCB for my minature Robot
Hello,
I'm at a point where I'd like to make PCB for my minature robot. Presently, it has three 1" x 1" Radio Shack general purpose PCBs stacked one above the other using some spacers. I have 30 day trial version of the Protel's s/w. I guess my question is many fold:
······· 1.····· How to tell Protel the dimensions of my board
······· 2.····· After done drawing, how do I go about making the pcb - with steps involved.
I know most of you guys have a lot of experience doing PCB stuff - if you can throw some light and point me to some text (or web site) explaining the process, that'll be really great!!!
Thanks in advance
nagi
PCB on the order of 100 hours without success.
Sean T. Lamont, CTO / Chief NetNerd, Abstract Software, Inc. (ServNet)
Seattle - Bellingham - Vancouver - Portland - Everett - Tacoma - Bremerton
email: lamont@a... WWW: http://www.serv.net
"...There's no moral, it's just a lot of stuff that happens". - H. Simpson
making PCBs with materials from Kepro. The process is very clean. I can
literally come up with an idea on Friday on the way home from work and have
a working project Sunday. The PCB software is Ares Lite. It's inexpensive
and does a great job. The software prints a negative mask on a laser
printer. The mask and Kepro boards are placed on the UV table to be
exposed. After the excposure, the board is developed in washing soda for
development. Afterwards you etch the board with sodium persulfate, which is
much cleaner and pleasant than ferric chloride. To agitate the board, I use
a foot massager. The entire set up cost me about $300 and I can make a 4" X
6" board for less than $4.
The article will be printed this December in Circuit Cellar Inc. I
encourage everyone to read a copy.
Paul
have any problems. I searched the internet for months and there are no other
printed circuit webpages that tell how to use standard printers,they all
expect you to have a laser printer. How many people have a laser printer
laying around,or special UV lamps?
Outsourcing is fine if you have $100 to spend on a single board. In
quantity is cheap for outsourcing but,one off production you will go broke
in a hurry.
Sincerely
Kerry
Admin@M...
WWW server hosting
[url=Http://mntnweb.com]Http://mntnweb.com[/url]
Binghamton online Webcam [url=Http://MntnWeb.Com/bing.htm]Http://MntnWeb.Com/bing.htm[/url]
CHRISTMAS Web Page [url=Http://mntnweb.com/xmas.htm]Http://mntnweb.com/xmas.htm[/url]
--So you think you need more memory... the LEM went to the moon on 16K,how
much do you REALLY need?
Thanks Paul, I shall look forward to this article
nagi
Original Message
From: Paul Verhage [noparse]/noparse][url=mailto:pverhage@sd131.k12.id.us]mailto[noparse]:p[/noparse]verhage@sd131.k12.id.us[/url
Sent: Monday, October 02, 2000 3:44 PM
To: 'basicstamps@egroups.com'
Subject: RE: [noparse][[/noparse]basicstamps] How to make a PCB for my minature Robot
The article I've written explains how to build an inexpensive UV table for
making PCBs with materials from Kepro.· The process is very clean.· I can
literally come up with an idea on Friday on the way home from work and have
a working project Sunday.· The PCB software is Ares Lite.· It's inexpensive
and does a great job.· The software prints a negative mask on a laser
printer.· The mask and Kepro boards are placed on the UV table to be
exposed.· After the excposure, the board is developed in washing soda for
development.· Afterwards you etch the board with sodium persulfate, which is
much cleaner and pleasant than ferric chloride.· To agitate the board, I use
a foot massager.· The entire set up cost me about $300 and I can make a 4" X
6" board for less than $4.
The article will be printed this December in Circuit Cellar Inc.· I
encourage everyone to read a copy.·
Paul
thru as I sent my letter out. In no way was I attempting to step on any
toes or criticize anyone,and I hope it will not be taken that way <S>
Sincerely
Kerry
Admin@M...
WWW server hosting
[url=Http://mntnweb.com]Http://mntnweb.com[/url]
Binghamton online Webcam [url=Http://MntnWeb.Com/bing.htm]Http://MntnWeb.Com/bing.htm[/url]
CHRISTMAS Web Page [url=Http://mntnweb.com/xmas.htm]Http://mntnweb.com/xmas.htm[/url]
--So you think you need more memory... the LEM went to the moon on 16K,how
much do you REALLY need?
still have some of the SOIC-8 to DIP-8 adapter boards available. You solder
the SOIC onto the adapter, then plug it into a regular DIP-8 socket, for
prototyping and so on. If anyone is interested, please contact me off list.
Thanks!
Steve
Steve Roberts: sroberts@s...
Go for positive photoresist. Works great!!! I have also tried the "marker"
method, did not work very well for me. All I do, is print out the board on
ink jet transparencies (... because I have an inkjet printer...) expose with
the regular florescent out in my garage, fix, and etch... Simple. Very Good
end product.
-Edward Kindler
I agree with Edward. I have tried all of the methods so far mentioned and
found that by far the easiest and simplest is using pre-sensitized positive
resist boards. You can get these at a very reasonable price from several
suppliers including Radio Shack.com. Most come with the developer. The next
best method is the negative resist however it requires a LOT more work. I
have the Datak equipment and supplies to do both types and can produce boards
up to 9" x 10" single or double sided.
You can get the Datak line from Jay-Tronics (www.jaytronics.com). You can
get the drill bits and a mini drill press from Jameco (www.jameco.com) quite
reasonable. The drill press is less than $30.00 and the bits are cheap as
well, all sizes.
For the layout work I have CircuitMaker Pro and TraxMaker Pro these cost
about $1600.00 total but you can get Eagle software for free that will do up
to a 3" x 4" board just by downloading it from their web page
(www.cadsoft.de).
I hope this will help you out.
Randy A.
Have you considered wire wrapping? Jameco sells a manual wrapping
tool for about $25. I prefer this method for single boards
primarily for the ease of making modifications/additions.
Adolph Stumpf
astumpf@u...
--- In basicstamps@egroups.com, nags <nags@c...> wrote:
> Hello,
>
> I'm at a point where I'd like to make PCB for my minature robot.
Presently,
> it has three 1" x 1" Radio Shack general purpose PCBs stacked one
above the
> other using some spacers. I have 30 day trial version of the
Protel's s/w. I
> guess my question is many fold:
>
> 1. How to tell Protel the dimensions of my board
> 2. After done drawing, how do I go about making the pcb -
with
> steps involved.
>
> I know most of you guys have a lot of experience doing PCB stuff -
if you
> can throw some light and point me to some text (or web site)
explaining the
> process, that'll be really great!!!
>
> Thanks in advance
> nagi
know where I can get free/share ware to do the PCB layouts? Thanks.
MH
Original Message
From: "Adolph Stumpf" <astumpf@u...>
To: <basicstamps@egroups.com>
Sent: Tuesday, October 03, 2000 2:11 PM
Subject: [noparse][[/noparse]basicstamps] Re: How to make a PCB for my minature Robot
> Nagi,
>
> Have you considered wire wrapping? Jameco sells a manual wrapping
> tool for about $25. I prefer this method for single boards
> primarily for the ease of making modifications/additions.
>
> Adolph Stumpf
> astumpf@u...
>
>
> --- In basicstamps@egroups.com, nags <nags@c...> wrote:
> > Hello,
> >
> > I'm at a point where I'd like to make PCB for my minature robot.
> Presently,
> > it has three 1" x 1" Radio Shack general purpose PCBs stacked one
> above the
> > other using some spacers. I have 30 day trial version of the
> Protel's s/w. I
> > guess my question is many fold:
> >
> > 1. How to tell Protel the dimensions of my board
> > 2. After done drawing, how do I go about making the pcb -
> with
> > steps involved.
> >
> > I know most of you guys have a lot of experience doing PCB stuff -
> if you
> > can throw some light and point me to some text (or web site)
> explaining the
> > process, that'll be really great!!!
> >
> > Thanks in advance
> > nagi
>
>
>
>
HREF="http://www.web-tronics.com/webtronics/printed-circuit-board-supplies.htm
l">Printed Circuit Board Supplies</A>
-Edward Kindler
Awesome site for PCB supplies, thanks a million for the link. Wish I had
found it before I purchased the etchant tank that I have. The one on that
site is infinately superior in design and the same price I paid for mine. Oh
well hindsight is 20/20. However, I will be getting my future supplies from
these guys.
Randy
price small runs.
I've hand drawn many boards: Using steel pen nib and thinned
paint. The trick is to DRILL THE HOLES FIRST! then mark
where the leads will be in pencil. [noparse][[/noparse]I draw it up 1:1 or 2:1
on graph paper and then glue a 1:1 onto the blank board
to serve as drill pattern guide - then pull drilled graph
paper off board, clean with copper pot cleaner goo and paint
lead pattern - etch]. Obviously only good for pretty simple
boards with .1 inch space components. But it only takes a
few hours to do.
If you can get access to a computer controlled sign router
you can do a board with a fie V tip router. Note that
often all you need to do is cut a bunch of channels to make
islands of copper - not elegant but works.
Note also dead bug prototypes style - ICs on back [noparse][[/noparse]"dead bug"]
and everything up in the air - you can use high value resistors
as standoffs from copper circuit board below. Hard to describe
but easy to see in picture [noparse][[/noparse]which I don't have...].
be creative... it's fun :-)
>Here is the cheapest source i have found for them:
>http://www.web-tronics.com/webtronics/printed-circuit-board-supplies.html
________________________________________________________________
YOU'RE PAYING TOO MUCH FOR THE INTERNET!
Juno now offers FREE Internet Access!
Try it today - there's no risk! For your FREE software, visit:
http://dl.www.juno.com/get/tagj.
> info on how
> to do it?
There is a product called Tin it that works OK, but is not as robust as real
plating. You have to get the material hot and it deposits a very thin
plating layer on the board.
>
> 2) They also have a clear or green coating on them. Not super sure what
> the purpose of it is (probably necessary for the tinning, but
> probably has
> other utility too). Can you point me to info on how to do it?
Solder masking? I haven't heard of an easy process to do this yourself. We
use a clear lacquer to protect the entire board after assembly.
>
> 3) They also have solder-through holes. Can you point me to
> info on how to
> do it?
Real PCB houses usually drill blank boards and deposit copper all over them
(they don't start with copper clad). This is not practical on a budget. Most
people use wire to connect both sides or eyelets through the holes. The
trick to using wire is to have "vias" between sides and solder the wire to
both sides.
>
> 4) Then there is the frigging drilling. If you're making one or
> two boards
> it's no big deal drilling by hand. But if you're making dozens of them,
> there should be some semi-cheap automated punch solution available. Any
> info on that?
Nope. We stack boards on a drill press when we make them here.
There used to be a site called www.thinktink.com that outlined the entire
process to make a "pro" PCB lab (with plating, and through hole, etc.). It
is either gone or down now, though. Be a shame if they are gone because it
was without doubt the best site on "pro" lab work.
Also read: http://fstewart.ne.mediaone.net/DaEtiCsuiPitdcrutNews.shtml
You might also enjoy: http://www.al-williams.com/wd5gnr/pcb.htm although
some of the links are out of date.
Regards,
Al Williams
AWC
* Control 8 servos at once: http://www.al-williams.com/awce/pak8.htm
> >I've enjoyed this thread, and look forward to the Ciarcia article, Paul.
> > Inspired me to sit down and write a few questions that have been bugging
> >me for a while.
>
> 1) Commercial boards have the pads tinned. Can you point me to info on
> how to do it?
At home, probably a chemical tinning like TINNIT is the only practical way.
Commercial places use plating tanks.
> 2) They also have a clear or green coating on them. Not super sure what
> the purpose of it is (probably necessary for the tinning, but probably has
> other utility too). Can you point me to info on how to do it?
This is solder resist to prevent solder bridges when wave soldering. This is a
epoxy ink that is screened on.
> 3) They also have solder-through holes. Can you point me to info on how
> to do it?
Pretty much impossible for the hobbyist. You can buy rivet type things to
peen in.
> 4) Then there is the frigging drilling. If you're making one or two
> boards it's no big deal drilling by hand. But if you're making dozens of
> them, there should be some semi-cheap automated punch solution available. Any
> info on that?
Usually drilled with CNC drill machine. You can stack boards when drilling.
> > 1) Commercial boards have the pads tinned. Can you point me to
> > info on how
> > to do it?
>
> There is a product called Tin it that works OK, but is not as robust as real
> plating. You have to get the material hot and it deposits a very thin
> plating layer on the board.
I bought some stuff called liquid tin, that worked at room temp. and worked
well. just drop the board in a bath of it, and it turns silver right away..
the longer you leave it, the thicker the plating..
--
________________________
Jason Lavoie
www.extremeroadshows.com
> article, Paul.
> >Inspired me to sit down and write a few questions that have
> been bugging me
> >for a while.
>
> 1) Commercial boards have the pads tinned. Can you point me
> to info on how
> to do it?
I personally don't tin. The boards I use are very clean after I etch them.
I find that if I solder them within a day or two, I don't need to tin.
there is a cold tinning process. You mix a dry powder with water and soak
the boards in it. This creates a replacement reaction. some of the copper
is replaced with tin.
> 2) They also have a clear or green coating on them. Not
> super sure what
> the purpose of it is (probably necessary for the tinning, but
> probably has
> other utility too). Can you point me to info on how to do it?
Green. I think you're referring to the coating put on PCBs after soldering.
It acts as an insulator and I imagine, an anti-oxidizing coating. I don't
use anything like that. It sounds like something to look into, though.
> 3) They also have solder-through holes. Can you point me to
> info on how to
> do it?
That's another one I don't do. I'm under the impression these are solder
rivets that are plugged into holes. I use single sided boards at this time.
However the method I use will let you create double sided boards. I'd start
with vias. These are wires you solder into boards to make an electrical
connection between the top and bottom.
> 4) Then there is the frigging drilling. If you're making
> one or two boards
> it's no big deal drilling by hand. But if you're making
> dozens of them,
> there should be some semi-cheap automated punch solution
> available. Any
> info on that?
I spend plenty of time drilling. A CNC machine might be the way to go, but
I don't know how to keep that cheap. That goes beyond the scope of my
article.
> 5) I checked out the Kepro page you recommend. They have a
> solder reflow
> vertical station. Is this for the pad tinning or is it for using
> surface-mount components? Seems odd if for components that
> it would be a
> vertical deal. Would think you would want board horizontal
> for components.
As I understand it, SMCs are "glued" into place, then soldered in mass in a
solder bath. I think that's what you're reading about. I'm old fashioned
and don't use SMCs (yet). The PCB lab I've created would let you work with
SMCs though. I feel sorry for those soldering SMCs. Its got to be hard on
the eyes.
> 6) Lastly, wondering if your system is scalable so that one
> could process
> let's say four boards at the same time?
I can shoot and etch three boards at a time. A larger UV table would let
you shoot more. I use a foot massager to etch. Since the boards are
hortizontal, I am limited to the number I can etch. But since it etchs
without supervisor, I haven't worried about doing more. I vertical tank in
the foot massager would let you etch more. I'll see what I can find. I
think it would be a nice upgrade.
> Thanks for the info. Lots of questions but maybe the answers
> are useful for
> others who are interested in doing a few dozen boards.
>
> Rich
I do 1,2 or 3 PCBs at a time and the method works great. I think I see
another article once I upgrade the process.
Paul
Al,
How do you hold your boards together while drilling? Does the drill move,
or the boards? The ones I have done (only single boards, not a stack), I
move the board underneath a stationary drill (well, I guess it's not
completely stationary ... it does move up and down <g>).
In order to drill a stack, you have to make sure all your boards are
accurately lined up ... can you describe how you acomplish that? I usually
cut my boards with a hobby knive, and don't get edges worthy of being used
as an alignment guide. Do you shear your boards? I did a little looking
but could not find a shear.
Thoughts?
-- Mitch
I'm clumsy), so usually someone who works for me does the actual physical
work. That being said, we will pick two holes on opposite corners of each
board and drill them by hand. Then we line up the holes and a piece of
perfboard with .1 inch spacing and make a stack that way. The top of the
stack has a laser print of the hole pattern on it. You should be able to
pass a drill bit through the whole stack where it has already been drilled,
or else something is wrong.
Then it is just a matter of moving the stack and drilling through the
perfboard. For small boards they use a small clamp to hold the edges of the
boards together. For larger ones, they will cut the boards flush after they
are lined up and use rubber bands.
We typically don't make boards here, by the way, but sometimes we have to
for whatever reason. We etch in FeCl3 (I know -- the other is so much
better) in a custom etching tank that uses an air pump and immersion heater
along with a homemade sparger (actually several depending on what kind of
boards we are doing).
For deposition of resist, we use direct transfer from release paper or clay
coat paper. This is the weak link. Once you have the process figured out, it
is easy, but it varies depending on your toner type, iron heat, etc. Even
then, you will ruin one or two boards out of a dozen (well, ruin as in you
have to wash the resist off and start over). If I had a better way to do
this, I'd consider doing small production runs in house. We have used the
photosense method, but I was not happy with making PMTs, exposing, and
developing. Not to mention stocking presense boards.
I've often wondered if you could get a sign shop to cut a stencil using a
vinyl swivel knife. Then you could just spray paint the resist on the boards
and it would be very quick. I haven't investigated this too far. I don't
think you could do very fine traces and of course no annular holes (think
about it).
Oh well, back to work.
Regards,
Al Williams
AWC
* Expand your Stamp I/O: http://www.al-williams.com/awce/pak3.htm
>
Original Message
> From: Mitchell D. Miller [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=BoUHmvz_DEM98QzxnQm57Y5lGq48xO6vgz61KaYziRyc4WuecLssZQdKT-ZHNOhDUorKiSBkf4TLrgc]mdmiller2@h...[/url
> Sent: Wednesday, October 04, 2000 11:36 AM
> To: basicstamps@egroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] RE: How to make a PCB for my minature Robot
>
>
> > Nope. We stack boards on a drill press when we make them here.
>
> Al,
>
> How do you hold your boards together while drilling? Does the drill move,
> or the boards? The ones I have done (only single boards, not a stack), I
> move the board underneath a stationary drill (well, I guess it's not
> completely stationary ... it does move up and down <g>).
>
> In order to drill a stack, you have to make sure all your boards are
> accurately lined up ... can you describe how you acomplish that?
> I usually
> cut my boards with a hobby knive, and don't get edges worthy of being used
> as an alignment guide. Do you shear your boards? I did a little looking
> but could not find a shear.
>
> Thoughts?
>
> -- Mitch
>
>
>
>
a
> solder bath. I think that's what you're reading about. I'm old fashioned
> and don't use SMCs (yet). The PCB lab I've created would let you work
with
> SMCs though. I feel sorry for those soldering SMCs. Its got to be hard
on
> the eyes.
The last board I did I used some SMC resistors, and I must say it isn't much
tougher to solder the component than it is to drill the .034" hole in the
center of pads at 0.1" spacing. In fact, my next board is going to use a
SMC processor (SX28AC/SO) so I don't have to drill the 28 holes for it!
I love the way SMC worked. I put the processor (ie: chip about to be
soldered) down on the board, untinned. Then, I put down a liberal amount of
liquid solder flux. Next, after making sure the chip is lined up well, I
solder opposite corners. After that, hold it in place with needle nosed
pliers, or similar tool, tin your iron well, and just run it down the length
of pins on one side ... every one, in turn, took it's solder from the tip of
the iron. About 1/2 way down, I stopped, retinned the iron, and finished
that side.
-- Mitch
I live in Minnesota. Do any of you guys know of a board maker shop here. I'd like to get abt 5 boards done. I like the idea of a shop making it than me doing it myself - not to mention, I will for sure screw it up if I did the boards myself.
thanks
nagi
Original Message
From: Mitchell D. Miller [noparse]/noparse][url=mailto:mdmiller2@home.com]mailto:mdmiller2@home.com[/url
Sent: Wednesday, October 04, 2000 12:14 PM
To: basicstamps@egroups.com
Subject: Re: [noparse][[/noparse]basicstamps] RE: How to make a PCB for my minature Robot
> As I understand it, SMCs are "glued" into place, then soldered in mass in
a
> solder bath.· I think that's what you're reading about.· I'm old fashioned
> and don't use SMCs (yet).· The PCB lab I've created would let you work
with
> SMCs though.· I feel sorry for those soldering SMCs.· Its got to be hard
on
> the eyes.
The last board I did I used some SMC resistors, and I must say it isn't much
tougher to solder the component than it is to drill the .034" hole in the
center of pads at 0.1" spacing.· In fact, my next board is going to use a
SMC processor (SX28AC/SO) so I don't have to drill the 28 holes for it!
I love the way SMC worked.· I put the processor (ie: chip about to be
soldered) down on the board, untinned.· Then, I put down a liberal amount of
liquid solder flux.· Next, after making sure the chip is lined up well, I
solder opposite corners.· After that, hold it in place with needle nosed
pliers, or similar tool, tin your iron well, and just run it down the length
of pins on one side ... every one, in turn, took it's solder from the tip of
the iron.· About 1/2 way down, I stopped, retinned the iron, and finished
that side.
-- Mitch
> the drill move,
> or the boards?
This is an interesting idea. Perhaps one could drill four holes in each PCB
seperately. make sure they're corner holes. Then line up the boards and
run pins through the holes. After you clamp them, they should be perfectly
aligned.
I think I'll give this a try.
Paul
>Inspired me to sit down and write a few questions that have been bugging me
>for a while.
1) Commercial boards have the pads tinned. Can you point me to info on how
to do it?
2) They also have a clear or green coating on them. Not super sure what
the purpose of it is (probably necessary for the tinning, but probably has
other utility too). Can you point me to info on how to do it?
3) They also have solder-through holes. Can you point me to info on how to
do it?
4) Then there is the frigging drilling. If you're making one or two boards
it's no big deal drilling by hand. But if you're making dozens of them,
there should be some semi-cheap automated punch solution available. Any
info on that?
5) I checked out the Kepro page you recommend. They have a solder reflow
vertical station. Is this for the pad tinning or is it for using
surface-mount components? Seems odd if for components that it would be a
vertical deal. Would think you would want board horizontal for components.
6) Lastly, wondering if your system is scalable so that one could process
let's say four boards at the same time?
Thanks for the info. Lots of questions but maybe the answers are useful for
others who are interested in doing a few dozen boards.
Rich
>Check my article in the December 2000 Circuit Cellar Inc. My article
>explains how I built a PCB lab for $300 that let's me design 4" X 6" PCBs
>for less than $4.00 a piece. These are single sided and very good quality.
>The BS/L boards I'm sending out are built with this system.
>
>Paul
>
>
>
>
_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
Share information about yourself, create your own public profile at
http://profiles.msn.com.
>I live in Minnesota. Do any of you guys know of a board maker shop here.
>I'd like to get abt 5 boards done. I like the idea of a shop making it
>than me doing it myself - not to mention, I will for sure screw it up if I
>did the boards myself.thanks
>nagi
Not in Minnesota, but check out Alberta Printed Circuits at
<http://www.apcircuits.com/>. I recommend them and others on this list have
too.
--
Greg
The green or clear mask on the board is for wave soldering the components
onto the board, it is called solder masking.
Tinning can be done with some relatively inexpensive chemicals, available
from Datak, Kepro and others.
The plated thru holes are a bit more difficult to do at home, however there
are "eyelets" that you can obtain, if you can find them, which serve the
same principle.
When doing large production runs the professionals use CNC drills to make the
holes.
Hope this helps some.
Randy