To edit an existing component in ExpressPCB :

1. Select the component you want to edit.
2. Click on the "Component" menu.
3. Select "Ungroup PCB Component".
4. Once you have done this, unselect the item, (by clicking somewhere else on the screen...)
5. double click the pad you want to edit, a window will pop up where you can change the size of the pad and drill hole.
6. make the changes you want......
7. once you are done editing, select the whole component again,
8. click on the component menu again
9. select "Group to make component"
10. then you can save the component under your favorite components....

You can make then any size you want, as long as you leave enough room between pads so you don't easily bridge the solder across 2 pads...

But you save as a custom component correct? So for example, I already have a number of diodes placed. I want to change the pad size of all of them. I need to first edit as you described, then replace all of the components?

 

I use staples brand photo paper, it has worked the best out of all the different ones I used when I used to use the toner transfer method, it is the Photo Basic Gloss (Item # 471861) it has 30 sheets in a package, cheaper than others too last time I bought some......

No problems with removing the paper as Sarge described?

 

No problems with removing the paper as Sarge described?

I didn't have much of a problem removing the paper, I usually just let it soak in some warm soapy water for about 20 minutes, then it rubs right off......

 

But you save as a custom component correct? So for example, I already have a number of diodes placed. I want to change the pad size of all of them. I need to first edit as you described, then replace all of the components?

Yes, you will have to replace all the existing components with the newly edited custom component.

 

I bought Staples Photo Basic Gloss (#648181, 50 sheets) the other day; it did not work well because it had a couple of thin layers of plastic material in it.

 

I bought Staples Photo Basic Gloss (#648181, 50 sheets) the other day; it did not work well because it had a couple of thin layers of plastic material in it.

You have to use the 471861 photo basic gloss, that's what worked for me, but like I said, it has been a while (maybe a couple of years) since I have bought any, so they may not have that particular item anymore....

 

Yes, you will have to replace all the existing components with the newly edited custom component.

How? I am only seeing Save Custom Component.

Do you just overlay the file? Or is there an easier way?

 

What is the best etchant to use? Considering I am snowed in and doing anything outside will be difficult. )

I have a basement but no garage.

I use cupric chloride or ferric chloride by the kitchen sink. Just don't get them too warm. Cupric chloride requires a bit more set-up and its endpoint is a bit more sensitive to detect, so I recommend ferric chloride with mechanical agitation (i.e., not a bubbler) over cupric chloride for your first attempts. You can warm it, but not too hot. Some people just take a pan of very hot water, put the etching bath in it, and that is sufficient. I would not go above a 55 to 60°C bath temperature with ferric chloride. 60°C is the temperature at which most people just start to feel a little pain, but it is not unbearable. I drill a hole in a corner of the board, thread a piece of thin plastic thread or tubing (e.g., polypropylene, polyethylene, or Teflon) and use that to rock the board. Polyester thread might also work for a one-time deal, but I have not tried it.

The peroxide-based methods, e.g., HCl or H2SO4 plus hydrogen peroxide are a bit more messy, in my experience. Remember, HCl is volatile; H2SO4 is not. So, splashes of sulfuric acid stay around and can get more concentrated with time.

As for the ammonium or sodium persulfate methods using the pre-made persulfates, I have very little experience with them. You are still dealing potentially with sulfuric acid, though.

In any case WEAR EYE PROTECTION --ALWAYS!

John

 

I use cupric chloride or ferric chloride by the kitchen sink. Just don't get them too warm. Cupric chloride requires a bit more set-up and its endpoint is a bit more sensitive to detect, so I recommend ferric chloride with mechanical agitation (i.e., not a bubbler) over cupric chloride for your first attempts. You can warm it, but not too hot. Some people just take a pan of very hot water, put the etching bath in it, and that is sufficient. I would not go above a 55 to 60°C bath temperature with ferric chloride. 60°C is the temperature at which most people just start to feel a little pain, but it is not unbearable. I drill a hole in a corner of the board, thread a piece of thin plastic thread or tubing (e.g., polypropylene, polyethylene, or Teflon) and use that to rock the board. Polyester thread might also work for a one-time deal, but I have not tried it.

The peroxide-based methods, e.g., HCl or H2SO4 plus hydrogen peroxide are a bit more messy, in my experience. Remember, HCl is volatile; H2SO4 is not. So, splashes of sulfuric acid stay around and can get more concentrated with time.

As for the ammonium or sodium persulfate methods using the pre-made persulfates, I have very little experience with them. You are still dealing potentially with sulfuric acid, though.

In any case WEAR EYE PROTECTION --ALWAYS!

John

So you would recomend or all of them ferric chloride for my first project then?

Where would I get it? How do I render it inert when I am finished? Can I strain it and use it again? If so, what would I use?

 

You have to use the 471861 photo basic gloss, that's what worked for me, but like I said, it has been a while (maybe a couple of years) since I have bought any, so they may not have that particular item anymore....

View attachment 16251

Looks like they still have it.

 

Looks like they still have it.

That is the #648181 which I purchased, and does not work well.
It is not the same as what BMorse bought, #471861, and does work well.

The devil is in the details. The packages look almost identical, but the quantity of sheets is different (50 vs 30) and the stock number is different - and so is the paper itself.

 

Here is a tip for you:
Use the "Place Filled Plane" on the bottom layer to create a copper fill.

This will save time and etchant, as you will not have to etch away as much of the copper. Read the help before using the feature.

 

So you would recomend or all of them ferric chloride for my first project then?

Where would I get it? How do I render it inert when I am finished? Can I strain it and use it again? If so, what would I use?

I would recommend ferric chloride for your first project. It is time proven and bullet proof.

Getting it is another issue. RadioShack used to carry it, but I have heard it is no longer available there. Wherever you buy the PCB might have it; also, the companies that sell the photoresist boards have it, like MG Chemicals.

Disposal of ferric chloride by itself is not a problem. It is sold as root killer to put down one's drains. The problem is the dissolved copper used etchant contains. Copper is a good fungicide, so some people put it in their swimming pools. Some let it dry out or add various solids to it to make it a paste and dispose of it in their trash (I don't believe small amounts are regulated, if not liquid). You might also consider the sanitary sewer, after checking local regulations for small producers. Ferric chloride is a coagulant used in most sewage treatment facilities.

To reiterate, the real concern as a waste product is the copper content, which is the same regardless of the etching method you use.* I like to use copper pours in my pcb design (e.g., ground planes) not only for their electrical advantages, but because you reduce significantly the amount of copper that needs to be etched. That allows your etchant to be used for more boards and reduces waste.

John

*Except for the cupric chloride, which is regenerated and the volume of useful etchant keeps growing.

 

That is the #648181 which I purchased, and does not work well.
It is not the same as what BMorse bought, #471861, and does work well.

The devil is in the details. The packages look almost identical, but the quantity of sheets is different (50 vs 30) and the stock number is different - and so is the paper itself.

You are VERY observant. I just did a search on BMorse's number and that is what came up.

I need to learn to look!!!!

 

I would recommend ferric chloride for your first project. It is time proven and bullet proof.

Getting it is another issue. RadioShack used to carry it, but I have heard it is no longer available there. Wherever you buy the PCB might have it; also, the companies that sell the photoresist boards have it, like MG Chemicals.

Disposal of ferric chloride by itself is not a problem. It is sold as root killer to put down one's drains. The problem is the dissolved copper used etchant contains. Copper is a good fungicide, so some people put it in their swimming pools. Some let it dry out or add various solids to it to make it a paste and dispose of it in their trash (I don't believe small amounts are regulated, if not liquid). You might also consider the sanitary sewer, after checking local regulations for small producers. Ferric chloride is a coagulant used in most sewage treatment facilities.

To reiterate, the real concern as a waste product is the copper content, which is the same regardless of the etching method you use.* I like to use copper pours in my pcb design (e.g., ground planes) not only for their electrical advantages, but because you reduce significantly the amount of copper that needs to be etched. That allows your etchant to be used for more boards and reduces waste.

John

*Except for the cupric chloride, which is regenerated and the volume of useful etchant keeps growing.

I was kind of hoping it was going to be one of those off the shelf products you get on the cheap. Can the root killer stuff be used? Or does it have chemicals in it?

These folks have it They carry a limited amount of items but they are good folks.

Can the stuff be reused?

I guess to save echant, I need a narrow container like this. Any tips on what to use?

Oh is there a stop rinse I need to do or just water?

 

You are VERY observant. I just did a search on BMorse's number and that is what came up.

I need to learn to look!!!!

Had I been observant in the first place, I wouldn't have bought what I did!

I had purchased a similar pack of Staples' Basic awhile back, but it must've been a different stock#, because it worked OK - but this new paper does not.

Just trying to save you from a similar pain in the keister as I have gone through in the last week. The magazine-paper ad flyers from the newspaper are like night and day difference.

I forgot to mention previously - don't handle the paper or the board with your fingers, as your finger oils will goof up the process. Use rubber gloves. Wash the outside of the gloves with dishwashing soap after you put them on to remove your finger oils.

 

These folks have it They carry a limited amount of items but they are good folks.

Shop around. You can buy it on ebay too.

Can the stuff be reused?

YES, usually many times. Keep using it until it stops working.

I guess to save echant, I need a narrow container like this. Any tips on what to use?

I just use a small Pyrex baking dish (about 4"X8"X3"high). Some people just sponge it on the board. If you do that, be sure to use gloves. Etching is actually an oxidation process, as opposed to simply dissolving the copper as a metal. Therefore, the sponge method works quite well and maximizes exposure to oxygen in the air.

Oh is there a stop rinse I need to do or just water?

No stop rinse. Just rinse in water. Note: If your sink is stainless, ferric chloride drips will quickly dull its surface. Have the water flowing and be very careful not to drip the concentrated ferric chloride on the SS. You could also have a rinse bath to get it diluted. There are lengthy articles all around about how to etch with lots of detail and pictures. I would suggest minimizing your investment, until you have done a few PCB's and know what to expect.

John

 

Had I been observant in the first place, I wouldn't have bought what I did!

I had purchased a similar pack of Staples' Basic awhile back, but it must've been a different stock#, because it worked OK - but this new paper does not.

Just trying to save you from a similar pain in the keister as I have gone through in the last week. The magazine-paper ad flyers from the newspaper are like night and day difference.

And thanks!!!

I forgot to mention previously - don't handle the paper or the board with your fingers, as your finger oils will goof up the process. Use rubber gloves. Wash the outside of the gloves with dishwashing soap after you put them on to remove your finger oils.

Knew that about the board but not about the paper. Makes sense. Now I need to make sure my paperboy was not eating jellyrolls when he delivers.


One other question that I asked above but did not see answered. How much do you need to heat the board? One guy I saw preheated it but then pointed out (which makes sense) you need to get it right the first time.

Do you really need to preheat?


Then he heated the heck out of it!! He filmed the whole heating process.

 

I haven't been pre-heating the blank board.

I use a scrap piece of plywood as a flat base to iron on.
I use two layers of thick paper towels over the scrap of plywood as a cheapie insulation layer.
I then put the board copper-side up on the layers of paper towels.
Then I make sure the iron is pre-heated to 300°F, +/- 15°F
Then I place the trimmed magazine print transfer toner-side down on the board, and line it up on two edges.
Then I put another single layer of paper towel down over that, just to make sure the iron doesn't stick to the magazine print paper - keeping one hand on the magazine print so that it doesn't shift.
Then I set the iron on it for maybe 20 seconds to warm up the toner, and then I move the iron around (picking it up and putting it back down; otherwise the steam holes in the bottom of the iron won't heat it up evenly) and let it rest for another 20 seconds or so.

I'll move the iron around several times, and then do a few edge/tip passes (tipping the iron slightly so that pressure is concentrated in just one line across the board) - the heel of the iron works OK for that.

If you have any pits or lines on the copper after soaking/brushing the magazine paper off, just touch it up with a Sharpie or similar type pen. Staedtler Lumocolor overhead projector marking pens (the red ones) work quite well as resist ink. Their black Lumocolors work OK too, but the reds work better.

 

I etched my first test board today. Not bad results. I used a cheap laminator from Target. About 4 runs through and let the board soak a few minutes and the magazine paper just falls right off. Etched using the muriatic acid + hydrogen peroxide solution. Few adjustments to do. Some pinholes in the larger traces and the trace edges are not as crisp (had to scrape a few before etching. I could tell from the few test runs through the printer that some of the lines (mostly the horizontal ones at the top of the page) looked like the toner speared in the printer or something.

Will try rotating the image so most of the major lines are vertical in the page. Not sure what to do about the pin holes. Perhaps let the laminator heat up longer, different paper, or I might try the other printer (I ran these through an old HP 4500, we also have a newer OKI 6100) since the HP doesn't seem to like the magazine paper.
Anyone having good results with other papers other than that older Staples photo basic? Magazine seems to be the most liked.


A CD Pen will also work for writing or filling in as I jsut wrote on the board to see if it would survive the acid soak (the one I have is TDK CD Mark)