Hello...
With this type (photo with transparency) of operation I can make board
for SMD, TQFP... down to 0.5mm pin pitch. But I'm not able to make one
big board with 20cm long connector. The difference in length is random
from death true to the 1mm! You can try to draw 20cm x 20cm rectangle
and print it. Then measure size of rectangle and diagonals. Printed
with LJ1018, LJ1020, (HL2030 little better) is just rubbish!. It's not
problem for board up to aprox 10x10cm as difference is small enought to
force connector into holes. And of course as I dril with CNC the wrong
size is not good thing either.
On 09/16/2013 05:56 AM, smilingcat90254 wrote:
> Just out of curiosity, why the vector writing an image. Sounds like it would take a long time to draw out your circuit pattern.
>
> I've gone from pulsar toner transfer paper (digi key part # 182-1003-nd) to a Puretch photo resist film (from http://www.capefearpress.com/puretch.html). I like my sources to be consistent and reliable. No offense to those who go Ebay route.
>
> I print my pattern on Highland Transparency film #78-6969-8593-2 (from office depot) and use my HP 2600 laser printer set on B&W only.
>
> Puretch film is applied to a clean copper clad board. set the printed image on top. Make sure there are no spaces between the image and the board. I use a 50W halogen light about 6" away for 2"x2" board. Expose for 15 minutes.
>
> remove protective mylar film, develop the resist in soda ash solution, pat dry. then expose the film for another 10 minutes under the halogen light to cure (harden) the resist.
>
> Etch.
>
> Seems less of a hassle than creating a vector printer. Image resolution is down to the resolution of my printer.
>
> Puretch claim they can resolve down to less than a mil line width. But my printer can't. :P
>
> You might want to give this a try. I use it to pattern TQFP and 0.5mm pitched parts along with 0402 components.
>
> Just a thought.
>
> And just follow the direction carefully on capefear youtube video. Lastly, the image has to be reversed. where you want the copper, you want a clear view. Where you don't want the copper the image on the transparency has to be black.
>
> Either way, I wish you lots of fun tinkering with solid state laser.
>
>
> --- In Homebrew_PCBs@yahoogroups.com, Slavko Kocjancic <eslavko@...> wrote:
>> I found that posts but there are 150mW laser involved. And this thing
>> isn't cheap. In other side the UV power led is cheap. And I think that
>> 3W UV led should compare to 150mW laser. (20x more power)
>>
>> And my intention is to make that beam aprox paralel to with size let's
>> say 1mm squared. And then to use aperture whell wit round holes from
>> 8mil up to 40mil, and used gerber stile data to work as old day
>> photoploter. Ie not raster scan but vectors...
>>
>> Just don't know if LED is good enought...
>> Slavko
>>
>>
>> On 09/14/2013 09:05 PM, designer_craig wrote:
>>> If you are interested in direct imaging a photo sensitized board search back
>>> through the posts around Nov of 09 for Volkan. He built a UV laser diode direct
>>> writer that did spectacular images. The 400 nm blue-ray lasers are available on
>>> ebay. He has some images posted under the Files secton of the forum. These UV
>>> lasers are very strong >> 100mW.
>>>
>>> I took him a board I had coated in AQ3000 (water based photo resist) to try an
>>> image. Once we got the exposure set the image was amazing crisp.
>>>
>>> Volkan also built a drum photo plotter.
>>>
>>> Both these project on my list of cool things to build.
>>>
>>> Craig
>>>
>>>
>
>
>
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