Homebrew PCBs

Great idea i will give it a try

gary


----- Original Message ----
From: Jim Hutchinson <jhutch17@...>
To: PCB_Homebrew <homebrew_pcbs@yahoogroups.com>
Sent: Sunday, March 4, 2007 8:00:12 AM
Subject: [Homebrew_PCBs] Toner Transfer

Hello to HB_PCB group
I am a new member and this is my first post ... the common thread in the 
TT process is difficultly in cleaning the paper residue from the bare 
copper after soaking and prior to etching ... the traces I make are 
usually 0.015 or larger and spacing is 0.015 or larger and the residue 
removal has been the most difficult step ... recently I was talking to a 
chemist friend about this problem and he suggested using some enzyme 
boosted washing powder (either automatic dishwasher powder or cloths 
washing powder) they have enzymes that convert oil to sugar, dirt to 
sugar and cellulose to sugar ... the clay coating on the paper I think 
is close to dirt and the paper fiber is cellulose ... I used Tide 
clothes washing powder (1 tsp to 1 and one half cup of water) at room 
temp ... after the initial soaking (in warm water) to remove the bulk 
paper and the rubbing of the residue with my thumb to remove as much of 
the residue as possible I now soak the PCB in the Tide solution and 
after about 5 minutes, almost all the residue in holes and between 
traces can be easily scrubbed off with a tooth brush ... an additional 
soak may be required for some real stubborn areas ... I now can be 
etching 30 minutes after image transfer ... I found the dish washing 
powder was too aggressive and would cause small pin holes if the soak 
was too long (it works but the timing in more critical ) I would like to 
hear from someone that has tried this ... it really seems to work for 
me . the toner I use is the toner that comes with my HP1022 laser 
printer ... it softens at about 230 degrees F and melts at 310 degrees F 
... I heat a 1 inch thick by 4 inches long and 3 inches wide piece of 
steel that I have ground flat to about 0.001 inch to about 350 degrees F 
... this is placed on top of the cover paper / image paper/blank PCB / 1 
inch thick wood stack and clamp it to about 250 pounds per sq inch for 1 
to 2 minutes ... the PCB is then put in the first water soak ... the 
transfer paper is Impreso Glossy Photo Paper for ink jet printers ... 47 
lb ... it is coated on both sides (I buy it at Frys Electronics) ... I 
have had good results with the TT process on small boards and with the 
enzyme soak to remove the residual paper/clay it is also a fast process ...
Jim KI6MZ





 
____________________________________________________________________________________
Sucker-punch spam with award-winning protection. 
Try the free Yahoo! Mail Beta.
http://advision.webevents.yahoo.com/mailbeta/features_spam.html

[Non-text portions of this message have been removed]