Hello Mark and Samson
Mark, Its too bad your day job interferes with your hobby!
In a previous post today, I briefly described how I modified (with
Mark's guidance) the E260 printer to directly print an toner image to a
PCB or other substrate.
I will now describe how I fix (harden) the PCB pattern to the copper
substrate.
When the PCB exits the printer with its pattern, the pattern is attached
to the PCB by an electrostatic charge. You can BANG the PCB on the table
and nothing comes off the PCB. But if you lightly touch the pattern, it
will smear. The usual way to harden the pattern is to use heat (up to
400 degrees F). Here is a method that uses NO heat.
The toner consists of finely ground poly-ester resin. Acetone will
dissolve this resin. In fact, Acetone solvent is the perfect way to
remove the toner after etching.
To FIX the toner to the PCB, without heat, in preparation to etch the
board, take a table spoon of acetone and put it in a glass dish that can
be covered and sealed. Put something in the bottom of the dish to place
the PCB on face up. I use stainless steel bolts. Seal the dish with a
glass pane or an acetone resistant plastic cover. Leave the PCB in the
VAPOR of the acetone for at least 2 minutes. Remove the PCB and allow
the acetone vapors to dissipate from the PCB (30 seconds). You can now
touch the toner traces without damaging them and the PCB is ready to etch.
Jim KI6MZ
On 9/8/2010 5:47 AM, Mark Lerman wrote:
> Hi Samson,
>
> Yes, I know that my final design does not fully mesh with the text.
> I've gotten bogged down at work and have not looked at this stuff for
> months. In conversation with some other people from this group (speak
> up if you wish), it seems that the KY can be eliminated by using foil
> over the leading edge of the pcb to connect the top and bottom
> layers. I'm hoping to get back to DLP in the next month or two -
> these are printers that might work even better that the E260.
>
> Mark
>
> At 08:03 PM 9/7/2010, you wrote:
>> Hey Mark,
>>
>> I just wanted you and everyone else to know--you are AWESOME.
>> Documentation is key to a lot of these projects, and your steps made
>> the modifications a BREEZE. I bought the E260 a few months ago, and
>> finally got around to modifying the printer! I just want everyone to
>> know that if you're about to pull the trigger, just do it because
>> the mod is very well documented and easy to do. The only thing I've
>> got to comment on is that the software steps are off from your
>> latest schematic and code, but I've figured that out. I'll probably
>> be publishing code for the PIC12F series in a few days, which I'd
>> imagine might be useful for some with dev toolchain setup.
>>
>> Once you get the process figured out for yourself, it really does
>> only take<5 minutes per print before etchant. Tape the board,
>> print, heat for 2 minutes at 400F (I use a griddle), and then a few
>> passes through the laminator and you're golden. It's SO much easier
>> than toner transfer, even with transfer paper, and the time savings
>> is definitely worth it for me. You also don't need any serious MechE
>> skills to do the mod, but you will have to get a few things off of
>> McMaster Carr. I'll probably post a few part numbers--I think I
>> found a cheaper version of that drive shaft which works fine.
>>
>> I've got to admit, I might be saying all of this somewhat early. I'm
>> still optimizing the process at this point, and later I'm planning
>> on working out the E&M and maybe getting control over however the
>> printer adjusts the transfer voltage, which varies depending on
>> substrate and other conditions.
>>
>> The prints are very very promising so far. I've been printing very
>> large black areas, which I know is most difficult for laser
>> printers, and I am getting pinholes, but much better than what I had
>> with toner transfer. There's still some open areas, but that seems
>> to be because I wasn't very careful with the lubricant spreading.
>> After etching, though, it's very clear that the toner areas are far
>> more solid than I've gotten with toner transfer--there's virtually
>> no leakage through the resist.
>>
>> I've also tried to print onto metal substrates (specifically
>> aluminum). It works with a few sheets of paper underneath the
>> aluminum carrier, but I'm not sure why. Without them, you get very
>> serious blotching in the image--I intend to work out the E&M
>> calculations sometime in the near future to figure out what's going
>> on. Maybe there's a more optimal stack, or I could try to change the
>> transfer voltage.
>>
>> Anyway, I just wanted to say thanks--this method is AWESOME. Let me
>> know how double sided is going--it does seem that the feeding
>> configuration doesn't really lend itself to particularly accurate
>> y-axis feeding, but it'd be awesome if double sided worked.
>>
>> Samson
>>
>>
>>
>> --- In Homebrew_PCBs@yahoogroups.com, Mark Lerman<mlerman@...> wrote:
>>> I am now working on producing ds boards. My first test was to see if
>>> I can print multiple times on one side of a board with good
>>> registration. If I can do that, I'm certain I can do the rest. I
>>> added a reflective sensor to locate the actual position in the motion
>>> (Y) axis. I could have used one of the leftover E260 interrupter type
>>> sensors, but it was easier for me to use black tape an white labels
>>> than to drill holes. In the final version, in the spirit of
>>> recycling, I might use a leftover. There are some pictures of the
>>> sensor and new mcu board on my pbase site<http://www.pbase.com/mark10970>.
>>>
>>> As I mentioned previously, when the carrier moves through the
>>> printer, the leading edge first hits the moving transfer roller,
>>> which pulls it up into the drum/transfer roller interface. This
>>> causes a variable delay, which messes up the registration. The "fix"
>>> is to wait till a couple of inches of carrier is completely through
>>> the interface before starting the actual timing (timing starts when
>>> pis is pulled low). I still have some work to do, but I'm pretty
>>> sure I can get it to work I printed a test with 5 mil traces - it was
>>> perfect in the Y axis, but about 5 mils off in the x axis. There is a
>>> picture on my pbase site.
>>>
>>> One problem I foresee is how to tell whether the sides are registered
>>> before etching. You can't see through the board before it is etched,
>>> and you don't want to etch it without knowing it is correct.
>>>
>>> Mark
>>>
>>
>>
>>
>> ------------------------------------
>>
>> Be sure to visit the group home and check for new Links, Files, and Photos:
>> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>>
>>
>>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>
>