I want to make a PCB with BGA ICs (up to 0.5mm pitch) DIY. Is that even possible ?

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I modified several laser printers to deposit toner directly on copperclad. It worked well but was a bit cumbersome at times and I had to drag out this big printer every time I wanted to use it. For me, using either pre sensitized boards or keeping a supply of boards I have previously laminated photosensitive film on seems like it would be very quick without the intermediate step of making transparencies.

Each to his own, but it's fun experimenting. Yesterday I was able to successfully remove the backlight from an Ipad screen I bought used. Will post when I have some results.

Mark



At 01:44 AM 12/29/2021, you wrote:

I don't see the point of that.
UV lamps are cheap adn so are printer transparencies.
My cheap inkjet can do 4800x2400DPI and good photoresist is cheap.

Compared to that, 3D printer is very crappy option.
I was thinking more along the lines of reworking something like Epson's
cheap A3+ Workforce WF-77xx printer or multifunction into printing
directly on PCB panel.

For me, that would be a meaningful change.
Pritner is GREAT in general, cheap and above all, great for exactly this
purpose.





On Tue, 28 Dec 2021 08:56:15 -0500
"Mark Lerman" <mlerman@...> wrote:

> There are a number of similar YouTube videos of this. I'm currently
> experimenting with doing the same thing, but in a different way. I
> bought a 9.7 inch 2K lcd with an HDMI board that I can use as a
> second monitor. I going to remove the backlight and replace it with a
> UV source. Print Eagle to a file then display the file on the lcd and
> use it to expose the board. This should allow a lot more flexibility
> from a software point of view. Also, the lcd on a resin printer has a
> (relatively) thick piece of glass on the front to protect the screen
> that could cause some refraction problems. Hopefully I'll get to try
> this in the next week or so.
>
> Mark
>
>
>
>
>
> At 10:44 PM 12/27/2021, you wrote:
> Anyone tried this? I feel foolish for not thinking of it.
> >
> > The fastest way to make crisp PCBs at home!
> >
> >
> >
> > The fastest way to make crisp PCBs at home!
> >
> >
> >
> >
> >
> >
> > Steve Greenfield AE7HD
> >
> > --
> > Steven Greenfield AE7HD
>
> Virus-free.
>
>
>

UV lamps and a good artwork are essential if more than one PCB is needed for a mini production run.
It is a decade or two since I played with it, but there is a big difference between printer resolution, artwork resolution, degree of opacity, and finished etched lines. What line width and spacing can you reliably achieve?

Here is a link to test patterns in both Gerber and AutoCAD formats plus the US Airforce 1951 Resolution Chart.


The direct imaging avoids the issues opacity and a clever idea for people having a 3D printer available.

A long time there was a member that modified an inkjet printer using a laser instead of the inkjet head, to directly expose the PCB.

Bertho

I don't see the point of that.
UV lamps are cheap adn so are printer transparencies.
My cheap inkjet can do 4800x2400DPI and good photoresist is cheap.

Compared to that, 3D printer is very crappy option.
I was thinking more along the lines of reworking something like Epson's
cheap A3+ Workforce WF-77xx printer or multifunction into printing
directly on PCB panel.

For me, that would be a meaningful change.
Pritner is GREAT in general, cheap and above all, great for exactly this
purpose.





On Tue, 28 Dec 2021 08:56:15 -0500
"Mark Lerman" <mlerman@...> wrote:

There are a number of similar YouTube videos of this. I'm currently
experimenting with doing the same thing, but in a different way. I
bought a 9.7 inch 2K lcd with an HDMI board that I can use as a
second monitor. I going to remove the backlight and replace it with a
UV source. Print Eagle to a file then display the file on the lcd and
use it to expose the board. This should allow a lot more flexibility
from a software point of view. Also, the lcd on a resin printer has a
(relatively) thick piece of glass on the front to protect the screen
that could cause some refraction problems. Hopefully I'll get to try
this in the next week or so.

Mark





At 10:44 PM 12/27/2021, you wrote:
Anyone tried this? I feel foolish for not thinking of it.

The fastest way to make crisp PCBs at home!



The fastest way to make crisp PCBs at home!






Steve Greenfield AE7HD

--
Steven Greenfield AE7HD

Virus-free. www.avg.com

There are a number of similar YouTube videos of this. I'm currently experimenting with doing the same thing, but in a different way. I bought a 9.7 inch 2K lcd with an HDMI board that I can use as a second monitor. I going to remove the backlight and replace it with a UV source. Print Eagle to a file then display the file on the lcd and use it to expose the board. This should allow a lot more flexibility from a software point of view. Also, the lcd on a resin printer has a (relatively) thick piece of glass on the front to protect the screen that could cause some refraction problems. Hopefully I'll get to try this in the next week or so.

Mark





At 10:44 PM 12/27/2021, you wrote:

Anyone tried this? I feel foolish for not thinking of it.

The fastest way to make crisp PCBs at home!

Steve Greenfield AE7HD

--
Steven Greenfield AE7HD

--
Steven Greenfield AE7HD

开云体育

I drill all ,y boards that have 100+ holes on CNC.

All boards I design in KiCAD from where I generate drill files.

As I mainly do single sided boards, I mirror output drill file over Y axis, and, as can be seen on the attached picture, I add 2 vias in TopLeft and BottomRight corner of the board for alignment on the bed. Vias are not drilled.

Drilling and cutting to size:

CNC machine is home made, chinese "TB6600" drivers, chineese 5axis Mach3 breakout board, driven from parallel port by Mach3 or from Arduino Nano + DB25 using bCNC

Howard,

A few more details are needed. Only you know what you have, EAGLE and cnc is a bit sparse. How about a photo or two of the CNC machine, make and model, servo controller make & model, and user computer to be used for user interface. In these types of arrangements the servo controller is a central component. Some are Arduino based, others ARM, a few use custom processors, although lately a few folks are using the UK based RaspBerry Pi as the 'brians' with a hat that is either a pin breakout board or has integrated servo/stepper motor drivers, etc. I am not a CNC guy myself, but I made a homebrew delta 3D printer. In the communities where I hang my hat, there are several groups that are cnc makers and these are the things I've seen posted. Between the controller and the User Computer is another peice of software which takes the tool path code file and squirts it into the controller which converts the commands into electrical control signals.

So provide some info, and people will help you. A photo of the CNC and the make and model, along with the controller info is a good start. Good Luck...

walt
--
SETV - Autonomous Instrumentation Platforms for the Detection & Measurement of Suspected ExtraTerrestrial Objects

Hi Vesselin,

I found it as surplus at a hamfest. Some of the electronics parts places down here in Australia sell boards coated with photoresist but I've never used any.

Regards,

Morris

My thanks to all those who responded. The suggestion of a soak in sodium hydroxide solution was the solution. At first I thought that didn't work because it didn't appear to dissolve the resist but after letting it soak for 5 minutes in hot NaOH solution the coating lifted right off.

I'm delighted to be able to use this PCB material at last!

Morris

On 15/10/21 6:39 am, Jim Higgins wrote:

Received from russell shaw at 10/14/2021 04:36 UTC:

If the PCB is small enough, put in the cold NaOH and then put it all in the microwave.

I don't recommend putting a copper clad PCB into an operating microwave oven. You'll have a real mess if you get local hot spots that cause the NaOH solution to splatter.

The copper is high enough electrical conductivity and the water high enough thermal conductivity that hot spots are never a problem (have atleast 1mm or more depth on top of the pcb).

Arcing due to high Q resonator effects never happen because the conductive solution is a resistive dampener.

I've been doing it for 10+ years.

Hi all
I have got hold of a cnc to use for drilling pcb's that I make with Eagle 6.4 pro but need some help with software and best way to set it up, would also like to be able to cut out the board
Hope I can get some help
Thanks
Howard

Received from russell shaw at 10/14/2021 04:36 UTC:

If the PCB is small enough, put in the cold NaOH and then put it all in the microwave.

I don't recommend putting a copper clad PCB into an operating microwave oven. You'll have a real mess if you get local hot spots that cause the NaOH solution to splatter.

JimH

In my process, developing uses sodium carbonate (washing soda) and
*developed* resist is removed with sodium hydroxide (lye). So if your
film is undeveloped, you might try the sodium carbonate first, with a
soak in the lye after for anything that remains. Or leave it in the
sunshine for an hour, then the lye.

Note: these are *soaks* not *wipes*. It takes time if you use the
dilutions you'll find in the online guides, since they're for using the
film, not just removing it.

There's no plastic coating. Not much joy from cold sodium hydroxide either but I'll? try it hot tomorrow.

Morris

On 13/10/21 8:11 pm, Morris Odell wrote:

Hi all,
I picked up a large sheet of surplus single sided copper clad board that is coated with a reddish colored photoresist. I don't know anything about it or whether it's positive or negative. I would like to remove the photoresist and just leave the copper layer so I can use it for toner transfer. The resist is not affected by acetone, turpentine or naphtha.
Any advice on where to go from here would be much appreciated.

It's likely to have a plastic film layer to protect it from air.

Lift a corner of it using the stickiness of some stick tape, to get it to peel.

Heat sodium hydroxide NaOH (garage/concrete floor cleaner or over cleaner) in a microwave to over 30degC (higher the better).

Put PCB in and the resist starts lifting in a minute.

If the PCB is small enough, put in the cold NaOH and then put it all in the microwave.

NaOH only needs to be 10g/Lt of water

Received from Morris Odell at 10/13/2021 23:31 UTC:

Alas not, I've tried both acetone and IPA and they don't touch it. I'll try MEK but I'm reluctant to try paint stripper because of methylene chloride toxicity.

If you try methylene chloride, just use it outdoors where it will work as well as it does inside, but you don't have to breathe it.

I suggest something alkaline... like dishwasher detergent powder... though an alkaline drain cleaner would probably be better. A couple of tablespoons of the cleaner in enough water to just cover the board all in a glass dish. Soak it a few minutes (drain cleaner) or maybe 15 minutes (dishwasher powder) then rinse it carefully (no splashing) down the drain and then the resist will probably come off with a pot scrubber.

Educated guess, not guaranteed. If you can look up the product on the Internet you would have something more specific to go on.

Good luck.

JimH