Homebrew PCBs

Hello,

Thanks for beer, here in Belgium we love beer...

You pupose a transparent spray for paper, wy not.

But, for photoresist, is necesary you expose with strong UV due to 20 
microns higth of the photoresist ==> is also necesary you have a very 
hard black film on pads and track normaly density 3 or 4.

But in industy, we d'ont use the black and transparent film, this 
film is the original film come from a lazer photoplotter.

We make a copy of the original film for 2 raison.

1, If we have a production problem ( foot on film, scratch...) we 
have a good original to make a new copy.

But an other very important raison:

With the black and transparent film, you d'ont see correctly to 
adjust your film and center the holes in the center of your pads.

We make a copy on a diazo amber film.

This film have an orange or amber transparent color on pads and 
tracks, he stop very strong the UV, and you can see the hole to 
adjust and register the pad in hole center.

This film is so simple to make, this film is an autopositive process, 
exposition with UV from your exposur unit, and developpement in vapor 
amonia, the same for architechtural plant.

We use A film from "ROHM&HAAS" type "ULTRAYIELD 200 or 300 or 310"
The problem for you is to obtain smal quatity, only box with 100 film.

But also the problem for you is to obtain a film have the correct 
dimmension, if you drill with a little CNC, you are correct with the 
coordinate "X" and "Y", bur your image have a deformation due to 
lazer cook.

But, for little dimension PCB perhaps you d'ont see this deformation.

I have a friend hi make a transparent on a inkjet printer, EPSON, and 
in A3, he have no deformation, this printer have 2 position scale for 
the 2 axes, and i am very impresioned with the precision if i see the 
difference of price of my photoploter and this little non expensive 
printer...

After print on the transparent, we make a copy on diazofilm, and no 
problem to expose with UV on dry film.

For dry film, we use "LAMINAR 5038" form "ROHM&HAAS"

The diazo film exist also from other fabricator, DUPONT and an other 
in Zwitserland.

Also with a friend, we make test with direct inkjet printing on the 
PCB plate after métalisation with special ink.

He is a group on YAHOO, and different site with this techinque.

http://blog.makezine.com/archive/2006/08/how_to_direct_to_pcb_ink_jet_
r.html

http://techref.massmind.org/techref/pcb/etch/directinkjetresist.htm

I have a big interest for this procedure for ptototype, because, no 
film, no copy, no dry film, no developement.

For direct inkjet image for simple face and etch with Fe3cl, non 
problem, the problem is for make a registration if i drill before 
inkjet printing, we see also in the futur if the special ink is 
resistant in copper and tin-lead electolitic bath.

We see, and make information to you in a few week.

For chemical trouhg holes line, from 10 year ago, i have make mysef 
the bath, but new procces are come on the market, and now we use a 
complete chemical line from "ROHM&HAAS" this proces is the "CRIMSON 
LINE" before, the name of this company is "SHIPLEY" he have good 
representation in europe and in USA.
But hi exist also an other system from "MACK DERMIT" this is 
the "BLACK HOLE".
From Bungard, i d'ont now the origin of the chemical, Bungard is not 
a fabricator of chemical, perhaps he make little bottle conditionment 
for you, i think this is an good idea for your market.

For copper and Tin or Tin-lead electro deposition, i make myself, 
this 2 bath are very stable, 8 or 10 years time life, no problem.

Just i buy the brigtner to "ROHM&HAAS" the brigtner is so difficult 
to make, this is a special preparation of "PEPTONE", hi come of 
muscle of animal, yes yes.

Other:

After etching with the process i have decribe, your Tin or tin-lead 
is MAT, to obtain glossy, is necesary to make a fusion with higt 
température oil, and heat gun, not automobile oil...but special oil, 
and this oil is clean after with watter and little of "DEFT" or "PER" 
or other liquid spons, the same use your wife to clean after 
heat...this oil is watter soluble.

To make start up solution for copper electro plating:
For 100 litres:

Demineralised watter : 54.00 liter
Sulfurik acid : 11.00 liter
Liquid copper sulfate: 29.00 liter
Brigtner type M : 4.00 litre
Brigtner type B : 0.25 litre
Brigtner type L : 0.25 litre
Ad the rest with demineralised watter.
Attention with Sulfiric acid, only acid in watter and not inverse 
watter in acid = explosion, very very dangerous!!!use glove and brill.
Add Sulfiric acid very very slowly, because you have big temperature 
elevation
Liquid copper sulfate is a 68.7 gr/litre special electro.

To make Tin-Lead start up solution electro plating:
For 100 litres:

Demineralised watter   : 50.00 litres
Fluoborik acid at 50%  : 30.00 litres
Borick acid             : 1.5 Kg disolved in warm watter before
Tin fluoborate at 50%  : 6.75 litres
Lead fluoborate at 50% : 2.25 litres
Brigtner A             : 1.75 litre
Brigtner B             : 1.75 litre
Brigtner R             : 1.00 litre
Complete with demineralised watter.
Put a back with 5 kilos of borick acid in a coin of thank permanently


Good amusement

Patrick





--- In Homebrew_PCBs@yahoogroups.com, "dandumit" <dandumit@...> wrote:
>
> Patrick and Markus, THANK YOU !
> I am following this group for more than one year but your revealings
> shared here it is the first professional  information that I have
> found it here. Are indeed some ingenious hacks in this group too but
> you two deserve a prize.  I would like you to have some beers on my
> account or a bottle of wine.
> 
> Continuing on trough hole plating :
> 1. Patrick - your solution it is very ingenious to have more simple 
> holes plated and ready etched. I have understood that in this 
process
> you use the film positive (tracks and pads are black) and the
> photoresist negative. This spray :
> http://www.crceurope.com/csp/web/ProdDisp.csp?
lng=3&country=ALL&product=TRANSPARANT%2021&business=ELECTRONIC
> Makes a regular printer paper transparent to UV light. Could you
> please tell us what could be used to replace it ? (of course a 
cheaper
> version). This way a regular laser print could be used as a film !
> 
> Patrick could you also give us some recipes some of baths ? Did you
> prepared at your work or you have bought them from a specialized 
company ?
> 
> 2. Suske - could you share with us from where do you plan to buy the
> chemicals for baths ?
> 
> Kind Regards,
> Daniel
>