new to etching

[3v0]

Is there some where locally you can get this chemical like home hardware ext. I live in Ontario, Canada. Digikey does not seem to have it in there cataloge.

The stuff I use is made by MG-Chemicals the 1Kilo bottle product number is 410-1KG. For MG-Chemical distributors in Ontario see

It is a starter kit, PCB Fab-In-A-Box by a company called Pulsar. Has 20 Sheets TTS, a role of green TRF, White TRF, 2PCS 8"x10" double sided .032", 1/2oz copper boards and 2 same spec. 8"x10" single sided boards.

I didn't buy the laminator they suggest, most of the boards I plane to make are small and I figure I can use a close iron.

I did use a progie called "expressPCB and ExpressSCH" but when you print out the laters they are not mirrored for the board. I will try the eagle program.

Eagle works great. The Beta version is easier to use but it is a beta.
I use the pulsar system with very good results. There site has a tips section that tells how to use a wood dowel under the PCB to simulate a laminator with a iron.

Most of the boards I make are small. I have a laminator and would not go back to using an iron. But thats me and YMMV.

Make sure to set your laser printer to max dark. You transfer can only be as good as what the laser printer prints.

I would be happy to answer any questions on using the kit. It is one of my favorite subjects.
The pulsar site has good info.

The same paper can be used to make decals. I have the spray adhesive but have not tried it yet. You can do some neat stuff with this system.

For SS boards I spray the top with Krylon Fusion white. This makes a nice background for a toner transfer of the topside artwork (silkscreen). I coat the artwork with conformal or clear acrylic.

EDIT:
I use 3M brand blue painters tape to tape the TTS paper to the printer paper to print the image. And the same to tape the TTS to the PCB to transfer the image.

 

[dasatboy]

Just going through this eagle program's tutorial. Obviously I'm new at this, but when they refer to a bus this meant as a means between two seperate objects, either though a ribbon, cable or such. Am I correct?

 

[Peter_wadley]

Yes as 3v0 suggest - I would buy from MG chemicals (Thats where I bought mine) .. well actually I bought it from a store called 'Sayal Electronics' .. Check to see if there is one near you .. they really offer everything you need except for speciality parts like MCUs ect.

Or search from a store called 'Active electronics'

As for the 'Bus' feature in eagle .. I believe (not 100percent though) that you basically lay it down .. lay a stripe of bus wire down.. in the program..

Then you use the 'Net' type of wire and make connections off of the bus ... you name these net wires... The bus basically just makes things more neat by allowing you to compact all of these nets in one wire... with the ablilty to using the different nets in the bus .. via their names..

I hope that makes sense.. sorry for the very shotty explaination.. just learned about them really

 

[3v0]

Peter is correct regarding meaning of bus. It is just a way to clean up a schematic.

Suppose you ran signals A-Z from one place to another on the schematic with a bus. When you layout the board it will be no different then if you had used a individual net/wire/line for each signal. A net that goes into a bus anywhere can exit the bus anywhere.

The wide blue lines in the attached schematic are buses. Notice how the top bus picks up all the signals related to the transistors. The bus on the bottom right has the signals for the switches and ICSP connector.

EDIT: If you give two physical nets the same name they will be connected whey you layout the board. In this schematic I got sloppy and did not cause RA6 and RA7 to join the intended bus at the processor. But they are shown as part of the bus in the area of the transistors. This still works because I have given each section of the net(s) the correct name.

You use this same feature used a lot for power and gnd. It would be messy to run these all over the schematic. Instead we show what they are with a label (ABC) after giving them the correct name.

Try these things out on a blank schematic and then make the board from it. Just a simple thing to see how it works.

 

[Krumlink]

Looks great Pommie!

Here is that same PCB with the components:

Looks good, but whats with the giant heat sink? To run it off 40VDC

 

[dasatboy]

I see said the blind man. Great to know. Basically a bus combines together several nets in one to clean up the work space. That will come in handy in my next project.

Now another question. Can I tell Eagle to only autoroute for a single layer PCB. I let it do it for me but I used a dual layer?

 

[3v0]

I see said the blind man. Great to know. Basically a bus combines together several nets in one to clean up the work space. That will come in handy in my next project.

Now another question. Can I tell Eagle to only autoroute for a single layer PCB. I let it do it for me but I used a dual layer?

Yes, when you click the autoroute tool it puts you in autoroute setup. Just pick N/A for the layer you want it NOT to route in.

The auto router is not all that great. Mostly you should be routing the traces by hand. One in a while I will use it to see if it can find a path that I missed but it is sort of a Hail Mary.

 

[dasatboy]

sorry guys I figured that answer out on my own Thanks

You must have typed this as I experimented>

 

[dasatboy]

LOL that is basicallly what I wanted to see. I used express PCB earlier in the week to rout my project. I placed the components close to the same place in the board here in eagle and ran auto route to see how close I was.

Is there any settings like clearence, thickness of routes ext. I should change from the default. Keeping in mind I am etching these boards!

I already ordered the etchant you recomended earlier and I do have a etching tank with air hose/pump (no heater I think), no laminator (as of yet - maybe in my next digikey order)?

 

[3v0]

Find the laminator that Pulsar recommends at officemax or the like.

Under change you will find settings for many things. Width will change the trace width that you lay down. Or if you change the width without hitting route any trace you click on will change width.

You need to use ERC and DRC. The DRC will tell you if there are problems with the board. There are many things you can set from the DRC setup.

Restring sets the size of pads as a percentage of the drill size.

With the pulsar system you should not have any problems using the eagle defaults. But to make things easier to solder you may want to increase clearance in the DRC. Start with a trace width of .016, I often use .012 and even .010 if the board is dense. Check the blue paper after you print it to ensure that the printer is doing its job. Do not use off brand or refilled toner cartridges.

Enough for now.

 

[dasatboy]

Thanks for all your help. I did do a quick draw up of a AVR Programmer I want to build. didn't change any of the settings yet. I will go through with you instructions. Attached is a copy of my schematic and the board layout.

As for laminator. I have a lamanator we use for documents and such. is this the same as one you use for PCB's?

 

[3v0]

As for laminator. I have a lamanator we use for documents and such. is this the same as one you use for PCB's?

Many such laminators will work. The one Puilsar sells/suggest is such a beast.

 

[dasatboy]

Thanks I will try mine and then if it does not work I will go buy the one from the site.

 

[3v0]

Just looked at you board. Unless you changed it red is used for the top side layer. Your traces should be on the bottom layer which would make them green like the pads.


Keep in mind that you do not have plated through holes so you need a via with a wire in it each time you change layers. You can not do it at a IC socket pin. You can do it at a resistor if you solder it top and bottom.

 

[Pommie]

Just looked at you board. Unless you changed it red is used for the top side layer. Your traces should be on the bottom layer which would make them green like the pads.

If you don't tell the printer, it won't know. Just make sure it isn't a mirror image thats printed.

Mike.
BTW, my bottom layer comes out blue.

 

[3v0]

If you don't tell the printer, it won't know. Just make sure it isn't a mirror image thats printed.

Mike.
BTW, my bottom layer comes out blue.

Correct, top red, bottom blue, pads green. Mind fart

You are right about the printing but he may as well get it right to start with.

 

[dasatboy]

Thanks both of you. I was thinking when I did it that copper will be on bottom.
but didn't apply it what I was doing "oops".

As for the via's ext. in this board I don't need to wory about them here do I, as all components will be soldered to copper on the bottom. Right?

I was just working the schematic for project #2 which will be a double sided board, I was going to use the Resistors as VIA's as you said this is good right?

 

[3v0]

Thanks both of you. I was thinking when I did it that copper will be on bottom.
but didn't apply it what I was doing "oops".

As for the via's ext. in this board I don't need to wory about them here do I, as all components will be soldered to copper on the bottom. Right?

Yes, your board has one layers and no jumpers.

I was just working the schematic for project #2 which will be a double sided board, I was going to use the Resistors as VIA's as you said this is good right?

Yes. If only a few resistors are used as vias I document which ones and add that info to a text file kept in the project directory. You can also look at the top side of the board and solder all resistors that have traces leading to them.

From the control panel you can do an edit description. This is at the project level. I use that to document what the major changes are for each rev of project.

 

[Pommie]

With your existing board, you can correct it by,

Use the group tool and draw a box around all the board.
Use the change tool and select layer 16-bottom.
Right click on any trace to change them all.

Mike.

 

[dasatboy]

thanks I will do this tonight!!