Recommend how to etch a circuit board?

[ants]

I need to etch a circuit board but having never done so I'm not sure what is the best and cheapest method to do this.

I'll be etching a pcb layout for an audio amplifier. It requires a pcb layout to prevent ground loop problems. I have the layout from the datasheet (page 8 ).

I'd welcome some practical suggestions. For example what thickness of trace, what board to start off with, should I get a kit or get power or fluid.

Thanks.

Ant.

 

[karesz]

Hallo,
If you know, that the LM has a pin distance (1 to 3) of ca. 3.4mm, than is the layout on the datasheet ca 50% of reality, also the thickest copper lines are at 2.5mm
Of course, you can have wider, but pls not less...
Check in Farnells Catalog/webside,they has lot of things for print making:
be care pls, its not less if you wish to make only one small PCB; it will be expensive, than you need chemicals, etch tank,(photosensitive)print materials
light box, good drill mashine (and inserts into), you can practically not drill it as freehand artist! _ need a standing mashine...
K.

 

[ants]

I was wondering about drilling. I could see it had the potential to ruin the board. The hint for traces at 2.5mm I will keep in mind. Sounds like I should buy a kit rather than the parts individually, that might end up being expensive.

Thanks.

 

[karesz]

NO, Stop!
I dont wish to try an "antireklam" for home mader!!
I wished only tell for you, that it has other aspects too, 6 these is much sum in money!
I began with my "lab" some time ago too, & its not finished _ but you need a hobby too (& it has prices)...
I see for 2.5 mm the widest traces as power & output lines.

Apropos, a possibility can be to try self maked layout/print: drow it per hand, with special pens! I maked it so 25 years ago too, finest lines from ca. 0.5 mm are Ok! .-)
You need normal FR4 copper plate (not photo sensitive!) and super fat less washing/cleaning!
Point the holes, drill it make it yet absolutely clean (from fat) & draw per hand the lines (of course you can make it per photo technique too, but for that needs lot of equipments) dry it.
Than etch in i.e. ferrum3 chloride some warm water solution...
Clean it & wash precious from chemicals, BE CARFULL, ITS VERY AGRESSIVE, makes clodes & flures broken for ever!
After least cleaning you can spray onto some flux for better solderability...
K.

 

[ants]

Thanks. I think I will have to do this in the garage so I don't ruin the carpets. I think a pen to draw the lines would be quite helpful and I'll be sure and make the traces wide enough. Will have to find the right size drill bit too, there are a few things I'll need!

 

[karesz]

Garage is a good idea_or a washroom too...
By drilling is not only the right size matter, your drill must have a stabile run, for PCB drilling is best a high tour dril_if possible over 10`000/min! and HSS drill bits (3.2mm shaft), need urgently a stative/table drill_NOT hand drill, that can you forget under 1.5..2.0 mm... Most components as resistors, signal transistors & capacitors has a contact diameter of 0.5mm, also you need a drill bit of i.e. 0.7-0.8mm, it will very light broken if you have a hand drill only! (I have such experience :-()
Dont forget by drilling; FR4=glass fibres + epoxy; is not good to inhal!!
K.

 

[keith1200rs]

I have done my own PCBs in the past by printing onto transparency with a laser printer and using photo resist PCB. For drilling you really need a small drill stand to keep the holes vertical and correctly spaced. To be quite honest - I wouldn't bother nowadays. You can get a PCB professionally made for around £30 - less than the cost of buying all the bits and chemicals to make your own. Even chopping down the PCB to size is a PITA with FR4 without the right tools.

Keith.

 

[karesz]

Hi Keith,
I can not agree with choppings problem to right size; OK all these is handwork, you need saw & file + eventuell a spanner...
Clear, you can have it from a prototype deliverer, but the most has more mony need as at 35£, that I know...
And the PREMIUM: I have self maked it ...
@ants;
Here some info: Tutorial - homemade PCB www.abotech.net/diy-pcb.html
DIY worktable,www.abotech.net/diy-worktable.html
Electronics -- Creating Two-Sided PCBs www.triplespark.net/elec/design/pcb/
K.

 

[ants]

I didn't know it was that cheap to have a pcb made up for me. It would certainly be fun to make it myself though.

Thanks for the input.

 

[keith1200rs]

I didn't know it was that cheap to have a pcb made up for me. It would certainly be fun to make it myself though.

Thanks for the input.

Prices are a lot lower due to the proliferation of "pooling" for PCB manufacture. It used to cost me £150 to get the most basic PCB made in the past - most of which was photoplotting/tooling costs.

I use PCB-Pool https://www.pcb-pool.com/ but I don't think they are the cheapest any more, but I stick with them because delivery & quality is good and they will take raw PCB files so I don't have to mess about creating Gerbers & NC drill files.

The "fun" of making your own may be dampened by the chemical spills, fibreglass dust, components that don't fit due to misaligned drilling, lack of ability to do fine tracks etc. Even if you want to "understand the process" you won't learn about hot air leveling, solder masks, plated through holes...

You can buy kits which have what you need such as:

https://cpc.farnell.com/1/1/67675-etching-kit-pnp-kits.html




but make sure you are comparing the contents - some are just "etch" kits.

At the very least, I would suggest using a free schematic/PCB package & printing to transparency. That way you at least learn some useful skills (schematic capture & layout) rather than learning how to draw with a pen!

It reminds me of when I was a kid (a long time ago). My mother remarked that I had re-arranged my bedroom - "just for a change" I said. What actually happened was I kept my ferric chloride solution in an old coffee jar in a cupboard and shoved a transmitter a bit too hard into the cupboard, smashing the jar and the contents ran all over the carpet. The re-arrangement hid the stain. She found it 15 years later when she moved house!

Keith.

 

[betwixt]

Ferric Chloride is nasty stuff. I remember an incident a few years back when someone spilled it down their trousers, it was a big spill. With no change of clothes at hand, they had no option but to keep them on until it dried. Apart from an ugly brown stain, everything seemed OK for the rest of the day but when they left to go home it was raining and as they walked out, they got wet and the fabric literally fell apart. They were more than embarrassed, wearing nothing below the waist except a belt and shoes and with brown sludge running down their legs!

On topic again: I did a mini-tutorial on making PCBs a few years back, you can see it at: http://www.atv-projects.com/Making_PCBs.html and there is an update on the etching tank on the same web site.

Brian.

 

[ants]

That pcb pool is a brilliant idea, I can see why it is popular and cheap. I guess the fun of making my own pcb would be somewhat limited by the accidents. If my wife knew I had acidic chemicals here at home she probably wouldn't be impressed. I was going to do this work in the garage and she'd be none the wiser!

So i'm going to order and have it done for me. There are plenty of people who are experts at this kind of work and I don't need to be.

Those are both very amusing anecdotes

 

[keith1200rs]

That pcb pool is a brilliant idea, I can see why it is popular and cheap.

Not only that, you can now get a free laser stencil. Not much use for most people, but handy if you are making your own SM PCBs. They also sell a cheap reflow kit based on a croissant oven!

Keith.

 

[karesz]

Hi Brian,
nice home side, congratulation!
@ants,
Dont worry, this stuff with chemicals isnt end of the world, you have handle with it carefully;its all!
I maked lot of PCBs at home, beginning with hand drawings_OK over ca. 0 years; no more, but its nice easy with a good water resist pencil & etching material (F3Cl) is in most pharmacy to become, often as 50% solution to! Your "mini-project", because it has wide copper lines, I would make surly in a short time per hand & finished!
You need max so 10 minutes if its not warm & the print is etched ...
Karesz